Saturday, December 31, 2005

 

Gram Positive Bacteria

GRAM-POSITIVE BACTERIA are characterised by having as part of their cell wall structure peptidoglycan as well as polysaccharides and/or teichoic acids. The peptidoglycans which are sometimes also called murein are heteropolymers of glycan strands, which are cross-linked through short peptides.

THE BASIS OF THE MUREIN are chains of alternating residues of N-acetylglucosamine and N-acetyl muramic acid which are Beta -1,4-linked. The muramic acid is a unique substance associated with bacterial cell walls. These chains are cross-linked by short polypetide chains consisting of both L- and D-aminoacids. While in Gram-negative bacteria the peptidoglycan is simple in structure and comparatively uniform throughout most genera, in Gram-positive bacteria there is a very big variation in structure and composition. In general the peptidoglycan is multilayered. There have also been recorded some minor variations in composition in some groups. Thus, in Mycobacterium and Nocardia the N-acetyl moiety of the muramic acid is replaced by the oxydised form N-glycolyl. The amino acid composition of the both the cross-linking as well the stem polypeptides can vary extensively with different groups. These differences form the basis for the taxonomy of these organisms.

THE LIPOPOLYSACCHARIDES of the Gram-positive bacteria have not been extensively studied apart from those of the streptococci, where they are the basis of their serological subdivision. They have also been used in investigating the serological relationships between streptococci, enterococci and lactobacilli. The specific polysaccharides associated with the acid-fast bacteria of the Corynebacterium-Mycobacterium-Nocardia group have also been extensively studied. They are arabinogalactans and arabinomannans linked to mycolic acids. The presence in the cell wall of these genera of arabinose, galactose and meso-diaminopimelic acid is characteristic of these genera.

THE TEICHOIC ACIDS , which are polyols consisting predominantly of glycerol, ribitol and mannitol, are covalently linked to the peptidoglycan through phosphodiester bonds and can be substituted by sugars, aminosugars or D-alanine residues. Some rare teichoic acids lack polyols. Teichoic acids are found in some actinomycetes, bacilli, lactobacilli, listeria and staphylococci.

IN ONLY A LIMITED NUMBER of Gram-positive genera including the Corynebacterium-Mycobacterium-Nocardia group are found the mycolic acids. They are 3-hydroxy acids of high molecular weight with a long alkyl branch in position 2.

MicroBioNet

FAMILIES OF GRAM POSITIVE BACTERIA

Bacillaceae

Species Profiles

CI. botulinum
B. anthracis
B. cereus
B. thuringiensis
B. mycoides

These are Gram-positive, sporing non-acid fast straight rods. If motile they have peritrichous flagellae. They include aerobes, facultative anaerobes, and strict anaerobes and are generally nonhalophylic with a wide growth range depending on the group. Many will grow on most simple bacteriological media. A variety of biochemical activities are noted in this family, including fermentative, proteolytic activities and the ability to grow on minimal media. Some species can fix nitrogen. A number of species are also characterised by producing specific toxins. Bacillus is the type genus. The two main genera Bacillus and Clostridium are distiguished by the former being aerobic, while the latter is anaerobic. Most of these include a wide variety of species.

Aerobic Genera

This is characteristic of the Bacillus and related groups. They are able to survive in air.

Bacillus: These are peritrichoulsly flagellated, form ellipsoidal or spherical, endospores, which may or may not swell the sporangium. They are aerobic to facultatively anaerobic and generally catalase positive. There are currently very many species in this genus, including, B. anthracis, B. azotoformans, B. cereus, B. coagulans, B. israelensis, B. larvae, B. mycoides, B. polymyxa, B. pumilis, B. stearothormophillus, B. subtilis, B. thuringiensis and B. validus. Many of these species form distinct groups of closely related species. One of these is the B. cereus group, which comprises apart from B. cereus, B. anthracis, B. mycoides and B. thuringiensis as well as newly described species, B. weihenstephanensis and B. pseudomycoides.

***Sporolactobacillus:

Sporocarcina
Filibacter
Caryophanum

Group Profile

B. cereus Group.

This is a group of gram-positive, spore-forming, generally motile, aerobic rod-shaped bacteria, which also grow well anaerobically. Based on recent 16S rRNA analysis the species including B. cereus, B. anthracis, B. mycoides and B. thuringiensis and the more recently identified B. pseudomycoides and B. weihendtephanensis, make up the group. The cells of these six species are all large, being >0.9µm wide. They produce ellipsoidal or cylindrical spores either centrally or subterminally. The spores do not distend the cells. They all form spores readily on most media. Based on detailed 16S and 23S rRNA analyses the members of the group have diverged only recently from a common evolutionary line. Due to its highly virulent pathogenicity B. anthracis has been maintained as a separate species, as has B. thuringiensis, whose strains form the crystalline inclusion (Cry protein) or d-endotoxin, which is highly toxic for certain types of insect. B. anthracis and B. cereus are the only members of the Bacillus genus, which are human pathogens.

Anaerobic Genera

This is the characteristic of the Clostridium group related groups and characterised generally by an inability to grow in air, although some may tolerate it.

Clostridium: These include many species, which can be psychrophilic, mesophilic or thermophilic. They are generally Gram-positive with peritrichous flagellation, they degrade organic materials to acids, alcohols, CO2, H2 and minerals. Acids, particularly butyric acid, are a frequent product of clostridial fermentation. They form ellipsoidal or spherical, endospores, which may or may not swell the sporangium. They tend to be grouped into saccharolytic, proteolytic species but some are both and there are also some species, which are specialised in being limited in their biochemical activities.

The saccharolytic species include: Cl. aerotolerans, Cl. aurantibutyricum, Cl. beijerinckii, Cl. botulinum B,E,F*, Cl. butyricum, Cl. chauvoei, Cl.difficile, Cl. intestinale, Cl. novyi A, Cl. pateurianum, Cl. saccharolyticum, Cl. septicum, Cl. thermoaceticum, and Cl. thermosaccharolyticum.

The proteolytic species include: Cl. argeninense, Cl. ghoni, Cl. limosum, Cl.putrefaciens, Cl. subterminale and Cl. tetani.

The proteolytic and saccharolytic species include: Cl. acetobutylicum, Cl. bifermenans, Cl. botulinum A, B, F (prot.)*, Cl. botulinum C,D*, Cl. cadaveris, Cl. haemolyticum, Cl. novyi B,C,* Cl. perfringens, Cl. putrefaciens, Cl. sordelli and Cl.sporogenes.

The specialist species include: Cl. acidiurici, Cl. irregularis, Cl. kluyveri, Cl. oxalicum, Cl. propionicum, Cl. sticklandii and Cl. villosum.

*Cl. botulinum is subdivided into a number of types according to the serological specificities of the toxins produced. These specificities are based on neutralisation studies. Other Clostridium species can also produce botulinum toxins.

***Micrococcaceae

These are Gram-positive, non-sporing non-acid fast cocci. They generally occur in tetrads (groups of four) or clusters and are not motile. They are generally aerobes and produce catalase. Carotenoid pigments are produced by most species. Most will grow on bacteriological media such as nutrient agar at 37°C except some psychrotropic and halophyllic species which require cooler temperatures or 5%NaCl. There are only two genera in this family; Arthrobacter and Micrococcus. The genera Staphylococcus and Planococcus which were once considered part of this family are now excluded, due to marked differences in DNA base composition, cell wall, fatty acids and other compositions.

Genera

Arthrobacter: This includes two 'groups of species', known as the A. globiformis / A.citreus group and the A. nicotianae group, based on differences in cell wall structure. They are important soil organisms, often being the numerically largest numbers of isolates on aerobic primary isolation media.

Micrococcus: This genus consists of nine species, of which M.luteus (previously known as M. lysodeikticus), M. lylae, M. roseus are most studied. M. agilis differs from other species in being motile, psychrophilic and producing beta-galactosidase. M. kristinae can ferment glucose anaerobically and M. halobius requires at least 5% NaCl for growth.

Species Profiles

M. luteus

***Mycobacteriaceae

These are Gram-positive, non-sporing acid fast straight or slightly curved bacilli. They are non-motile and range in size between 0.2-0.6 x 1.0-10 mµ). Both branching and mycelium-like growth may occur. They are generally aerobes and produce catalase. Many species form white or creamy coloured colonies but some form bright yellow or orange colonies based on carotenoid pigments, in some cases only as a response to light. They can utilise a wide range of carbon compounds. Glycerol is utilised by all cultivable mycobacteria as sole source of carbon and energy, thus media conating this substrate will grow most species. There may also be a requirement for additional CO2 particularly for clinical isolates. There is only one genus in this family; Mycobacterium. Recent studies based on 16S rRNA analyses have suggested that the family Mycobacteriaceae should include the three genera: Mycobacterium, Nocardia, Rhodococcus.

The Genus

Mycobacterium: On the basis of growth rate, this includes two groups of species, known as the Slow Growers and the Fast Growers. The Slow Growers tend to be associated with human or animal disease, while the Fast Growers tend to be non-pathogenic. They are widely distributed in soil and some marine environments. Over 300 species have been named. The GC content of the DNA of those mycobacterial species studies varies from 66-71 mol%.

Species Profiles

Mycobacterium tuberculosis

***Peptococcaceae

These are Gram-positive, non-sporing non-acid fast cocci. They are strict anaerobes and are generally nonhalophylic with a wide growth range depending on the group. Some will grow on the most simple bacteriological media, while special nutrients are required by others. These may include vitamins, other cofactors and amino acids. Many metabolize peptones and amino acids. Some require fermentable carbohydrates. A variety of biochemical activities are noted in this family, including some fermenters, some produce indole, reduce nitrate, produce urease, coagulase or catalase etc. Peptococcus is the type genus. The other genera include Peptostreptococcus, Sarcina and Coprococcus. Most of these include a wide variety of species.

Genera

Peptococcus: This includes only one species, P. niger. The cocci are arranged as diplococci, irregular clumps or regular clusters. They are anaerobic and n-caproic acid and butyric acid are the main metabolic products.

Peptostreptococcus: This genus consists of three groups of species. Ps. anaerobius is the only representative of one group. It is biochemically similar to P.niger, but grows confluently on commercial media. It forms short chains. The other two groups, which tend to form clumps and clusters; some species form diplococci, which are distinguished by their ability to form butyrate or not. Each group includes about five-six species, which are differentiated on their morphology and biochemical reactions including fermentation, reduction of nitrate, production of indole, urease, coagulase or catalase etc.

Ruminococcus:

Sarcina :
Coprococcus:

Species Profiles
P. Niger

Thursday, December 22, 2005

 

NHS 'failing' on lethal bacterial infection

NHS trusts are not doing enough to stop patients contracting a potentially fatal infection, watchdogs say.

Clostridium difficile caused just under 1,000 deaths in 2003, figures for England show.
The Health Protection Agency and the Healthcare Commission found a third of the English trusts surveyed do not routinely follow official guidelines.

Key measures to reduce risk include careful use of antibiotics and being able to isolate infected patients.

The organisations' full report is set to be published in the spring. But interim results have been released now, prior to the peak time for C.difficile infections.

C.difficile is a common hospital-acquired infection which usually causes diarrhoea but can lead to fevers or more serious infections.

The first set of data from a mandatory reporting scheme last year showed there had been over 44,000 cases of the infection in hospitals in England.

The Healthcare Commission and the Health Protection Agency surveyed directors of infection prevention and control at 118 of the 173 trusts in England.

Most directors felt the incidence of C.difficile was rising.

However 38% did not have restrictions on the use of antibiotics.

The Healthcare Commission's Marcia Fry, who headed the survey, told BBC Radio 4's Today programme that the overuse of antibiotics was a major problem.

"What they [antibiotics] do is destroy the good bacteria in the gut and allow the infection with the C.difficile to take hold.

"You want more targeted antibiotics to the specific problem being treated - but to get control of antibiotic prescription across a trust or across a community is not an easy thing to do."
In addition, over a third of the trusts surveyed said they could not isolate patients routinely, and only 11% of trusts have a ward that can be used for isolating patients with C.difficile.

Isolation call

The survey even found that hospitals do not agree on what constitutes an outbreak.
And many said their trusts did not follow guidelines on who should be informed when they did have an outbreak.

Sixty-five per cent admitted their trusts do not routinely record information on deaths from C.difficile.

Nigel Edwards, policy director of the NHS confederation representing NHS trusts, said trusts had been put under "very high pressure" by a "very large push" to take care of other priorities.
"If you're short of facilities and you're really anxious to get your elective surgery patients in and your cancer patients in, some trade-offs may be being made there," he told Today.
This made implementation of guidance "difficult in particular circumstances", he added.

'Most advanced'

The HPA and the commission recommend trusts adhere to "best practice" guidelines on antibiotic prescribing, review their ability to isolate patients and to ensure they comply with the requirement to report all C.difficile infections in over 65s.

Professor Peter Borriello, director of the Centre for Infections at the Health Protection Agency, added: "The results of this survey will help us to improve our surveillance of C. difficile and learn more about how trusts treat patients and tackle outbreaks."

Health Minister, Jane Kennedy, said the NHS system of C.difficile surveillance was "now the most advanced in the world".

But she accepted some trusts still had work to do.

"The new Hygiene Code currently undergoing scrutiny in Parliament will make it a statutory duty for trusts to have all these systems in place; and the Healthcare Commission will have the power to issue improvement notices if hospitals are failing to carry out these measures."
Ms Kennedy added that the Chief Medical Officer had written a "firm reminder" to all trusts, reminding them of the steps they should be taking to minimise the risk of C. difficile.
Shadow Health Secretary Andrew Lansley said: "Every hospital should achieve the highest level of cleanliness. Despite countless government initiatives, standards remain unacceptably low."
Steve Webb, Liberal Democrat health spokesman, said the government was "guilty of gross complacency on this issue and should sit up and take notice of their own inspectors".
C. difficile hit the headlines in June after it emerged that more than 300 patients at Stoke Mandeville Hospital, in Buckinghamshire, had contracted the infection and 12 elderly patients had died after contracting it since 2003.

BBC NEWS

Tuesday, December 20, 2005

 

Bacterial Pneumonia

WHAT YOU SHOULD KNOW

Bacterial pneumonia is an infection that causes irritation, swelling, and congestion in the lungs. It is also called bacterial pneumonitis (new-mo-NI-tis). It occurs most often in the winter.

Causes


This type of pneumonia results when bacteria are inhaled and settle in the lungs.

Signs/Symptoms


This illness usually follows a cold. It often starts suddenly with a high fever (over 102 degrees F or 38.9 degrees C) and chills. Difficult or painful breathing and a cough with bloody or yellow sputum are common symptoms. Other signs may include fast breathing, tiredness, abdominal pain, and blue or pale lips and nailbeds.

Care


If you have no other illnesses or problems, you can be treated at home. This care will include antibiotics, a humidifier to loosen your sputum (making it easier to cough up), and rest.

If your condition gets worse, or if you have other problems (such as diabetes or heart failure), you may need a stay in the hospital. There your care will be similar, but you can be carefully watched.

Risks


Without treatment, the infection could spread and become a threat to your life. Your lung problems could become worse--possibly even fatal.

WHAT YOU SHOULD DO

Take your antibiotics as directed until they are all gone--even if you feel well. If you don't think they are helping, call your doctor. Do not quit taking them on your own.

If you are taking medicine that makes you drowsy, do not drive or use heavy equipment.


If you are coughing up sputum and milk seems to make the sputum thicker, do not eat or drink foods that contain milk.


To help free your lungs of infection, take 2 or 3 deep breaths and then cough. Do this often during the day.


If you do not have to limit the amount of liquids you drink, drink 8 to 10 (soda-can sized) glasses of water each day. This helps thin the sputum so it can be coughed up more easily.


Use a humidifier to help keep the air moist and your sputum thin. This makes it easier to cough up the sputum. You must keep the humidifier free of fungus. Clean it every day.


Stay inside during very cold or hot weather, or on days when the air pollution is high. This will make it easier to breathe and will help control your cough.


Rest at home until you feel better. You may return to work or school when your temperature is around 98.6 degrees F (37 degrees C). Slowly increase your activity. You may feel weak and tired for up to 6 weeks after your illness.


If you have chest pain, apply a heating pad (set on low) or warm cloths to the sore area for 10 to 20 minutes, 2 to 3 times a day. This may ease the pain, making it easier to breathe.


Because you have had pneumonia, it may be easier for you to get other lung infections. Try to stay away from people who have colds or the flu. Get shots against flu and pneumonia.


Quit smoking. It harms the lungs. If you are having trouble quitting, ask your doctor for help.


Make an appointment for another chest x-ray, if your doctor thinks one is necessary.


Call Your Doctor If...


You have a high temperature.
Your medicine does not relieve your chest pain within a few days.
You get nauseated, or have vomiting or diarrhea.
You are coughing up bloody or pink, frothy sputum.
You have problems, such as a rash, itching, swelling, or stomach pain, that may be caused by your medicine.
Another family member shows signs of pneumonia.


Seek Care Immediately If...

You have a lot of trouble breathing or have blue or pale skin, lips, or nailbeds.
You have a severe headache, neck stiffness, or feel confused.
You continue to have fever and chills and feel worse even when taking your medicine.


IF YOU'RE HEADING FOR THE HOSPITAL...


What to Expect While You're ThereYou may encounter the following procedures and equipment during your stay.

Activity: At first you will need to rest in bed, with a few pillows to keep you sitting up a little. This will help your breathing. Do not lie flat. Once you are breathing more easily, you will be allowed to increase your exercise.


Taking Vital Signs: These include your temperature, blood pressure, pulse (counting your heartbeats), and respirations (counting your breaths). A stethoscope is used to listen to your heart and lungs. Your blood pressure is taken by wrapping a cuff around your arm.


Oxygen: Your body may need extra oxygen at this time. It is given either by a mask or nasal prongs. Tell your doctor if the oxygen is drying out your nose or if the nasal prongs bother you.

Pulse Oximeter: While you are getting oxygen, you may be hooked up to a pulse oximeter (ox-IM-ih-ter). It is placed on your ear, finger, or toe and is connected to a machine that measures the oxygen in your blood.


ECG: Also called a heart monitor, an electrocardiograph (e-LEK-tro-CAR-dee-o-graf), or EKG.


The patches on your chest are hooked up to a TV-type screen or a small portable box (telemetry unit). This screen shows a tracing of each heartbeat. Your heart will be watched for signs of injury or damage that could be related to your illness.

12 Lead ECG: This test makes tracings from different parts of your heart. It can help your doctor decide whether there is a heart problem.


Chest X-ray: This picture of your lungs and heart shows how well they are handling your illness.
Blood: Usually taken from a vein in your hand or from the bend in your elbow. Tests will be done on the blood.


Blood Gases: Blood is taken from an artery in your wrist, elbow, or groin and tested for the amount of oxygen it contains.


IV: A tube placed in your vein for giving medicine or liquids. It will be capped or have tubing connected to it.

Medicines:

Antibiotics are given to fight infection. They may be given in your IV, in a shot, or by mouth.


Expectorants (ex-PEK-ter-ants) may also be given to help thin your sputum so it is easier to cough up.


Coughing and Deep Breathing: It is important to do this often because it helps clear your lungs of infection.

To ease your pain during coughing and deep breathing, you may need to loosely wrap your rib cage with a 6-inch elastic bandage.

Holding a pillow tightly against your chest when you cough can help reduce the pain. Lying on the side that is hurting may also help ease the pain.


Heat: A warm towel or heating pad (set on low) may help ease your chest pain.
Sputum Sample: If you are coughing up sputum, your doctor may need to send a sample to the lab. From this sample, the lab can determine which kind of bacteria are causing your illness. This helps the doctor choose the medicine you need.


Postural Drainage: Periodically, a nurse may tap briskly on your back with his or her hands. This helps loosen the sputum in your lungs so you can cough it up more easily.


After You Leave


Follow the directions listed under "What You Should Do.''

-----------

See Also:

Bacterial Pneumonia

Bacterial Pneumonia - An Overview

Pneumonia Fact Sheet

Monday, December 19, 2005

 

Information Links for Bacterial Infections

Follow the links below to find information on infections caused by bacteria. For information on specific infections, such as gastroenteritis or pneumococcal disease, follow the links to those topic pages.

Updated November 2005

Anthrax HealthInsite Topic Page Links to information about anthrax.

Antibiotics HealthInsite Topic Page Links to information relating to antibiotics.

Diarrhoea HealthInsite Topic Page Links to information about the causes and treatment of diarrhoea.

Diphtheria HealthInsite Topic Page Links to information about diphtheria.

Golden Staph HealthInsite Topic Page Links to information relating to golden staph infections.

Haemophilus Influenzae Type B (HIB) HealthInsite Topic Page Links to information on haemophilus infections, including immunisation for HIB.

Impetigo HealthInsite Topic Page Links to information relating to impetigo.

Listeria and Listeriosis HealthInsite Topic Page Links to resources about listeria bacteria and associated listeriosis infections.

Meningitis and Meningococcal Infections HealthInsite Topic Page Links to resources on the various types of meningitis and meningococcal infections, their causes and symptoms.

Peptic Ulcer HealthInsite Topic Page Links to information on peptic or stomach ulcers.

Pneumococcal Disease HealthInsite Topic Page Links to resources about pneumococcal disease.

Q Fever HealthInsite Topic Page Links to information about Q fever.

Salmonella HealthInsite Topic Page Links to information on salmonella infections.

Sexually Transmitted Infections HealthInsite Topic Page Links to resources relating to sexually transmitted infections (STIs or STDs) and their prevention.

Streptococcal Disease HealthInsite Topic Page Links to information relating streptococcal disease

Tetanus HealthInsite Topic Page Links to information about tetanus.

Urinary Tract Infections HealthInsite Topic Page Links to resources relating to urinary tract infections.

Sunday, December 18, 2005

 

Bacterial Meningitis

Bacterial meningitis is a serious infection of the fluid in the spinal cord and the fluid that surrounds the brain.

Bacterial meningitis is most commonly caused by one of three types of bacteria: Haemophilus influenzae type b, Neisseria meningitidis, and Streptococcus pneumoniae bacteria.

The bacteria are spread by direct close contact with the discharges from the nose or throat of an infected person.

Bacterial meningitis can be treated with antibiotics.

Prevention depends on use of vaccines, rapid diagnosis, and prompt treatment of close personal contacts.

What is bacterial meningitis?


Meningitis is an infection of the fluid in the spinal cord and the fluid that surrounds the brain. Meningitis is usually caused by an infection with a virus or a bacterium. Knowing whether meningitis is caused by a virus or a bacterium is important because of differences in the seriousness of the illness and the treatment needed.

VIRAL MENINGITIS is usually relatively mild. It clears up within a week or two without specific treatment. Viral meningitis is also called aseptic meningitis.

BACTERIAL MENINGITIS is much more serious. It can cause severe disease that can result in brain damage and even death.

What bacteria cause bacterial meningitis?


Bacterial meningitis is most commonly caused by one of three types of bacteria: Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Streptococcus pneumoniae.

Before the 1990s, Hib was the leading cause of bacterial meningitis, but new vaccines being given to children as part of their routine immunizations have reduced the occurrence of serious Hib disease. Today, Neisseria meningitidis and Streptococcus pneumoniae are the leading causes of bacterial meningitis.

Meningitis caused by Neisseria meningitidis is also called MENINGOCOCCAL MENINGITIS.

Meningitis caused by Streptococcus pneumoniae is called PNEUMOCOCCAL MENINGITIS.

It is important to know which type of bacteria is causing the bacterial meningitis because antibiotics can prevent some types from spreading and infecting other people.

Where is bacterial meningitis found?


Bacterial meningitis is found worldwide. The bacteria often live harmlessly in a person's mouth and throat. In rare instances, however, they can break through the body's immune defenses and travel to the fluid surrounding the brain and spinal cord. There they begin to multiply quickly. Soon, the thin membrane that covers the brain and spinal cord (meninges) becomes swollen and inflamed, leading to the classic symptoms of meningitis.

How do people get bacterial meningitis?


The bacteria are spread by direct close contact with the discharges from the nose or throat of an infected person. Fortunately, none of the bacteria that cause meningitis are very contagious, and they are not spread by casual contact or by simply breathing the air where a person with meningitis has been.

What are the signs and symptoms of bacterial meningitis?


In persons over age 2, common symptoms are high fever, headache, and stiff neck. These symptoms can develop over several hours, or they may take 1 to 2 days. Other symptoms can include nausea, vomiting, sensitivity to light, confusion, and sleepiness. In advanced disease, bruises develop under the skin and spread quickly.

In newborns and infants, the typical symptoms of fever, headache, and neck stiffness may be hard to detect. Other signs in babies might be inactivity, irritability, vomiting, and poor feeding.
As the disease progresses, patients of any age can have seizures.

Who is at risk for bacterial meningitis?


Anyone can get bacterial meningitis, but it is most common in infants and children. People who have had close or prolonged contact with a patient with meningitis caused by Neisseria meningitidis or Hib can also be at increased risk. This includes people in the same household or day-care center, or anyone with direct contact with discharges from a meningitis patient's mouth or nose.

How is bacterial meningitis diagnosed?


The diagnosis is usually made by growing bacteria from a sample of spinal fluid. The spinal fluid is obtained by a spinal tap. A doctor inserts a needle into the lower back and removes some fluid from the spinal canal. Identification of the type of bacteria responsible for the meningitis is important for the selection of correct antibiotic treatment.

What complications can result from bacterial meningitis?

Advanced bacterial meningitis can lead to brain damage, coma, and death. Survivors can suffer long-term complications, including hearing loss, mental retardation, paralysis, and seizures.

What is the treatment for bacterial meningitis?


Early diagnosis and treatment are very important. If symptoms occur, the patient should see a doctor right away. Bacterial meningitis can be treated with a number of effective antibiotics. It is important, however, that treatment be started early.

How common is bacterial meningitis?


In the United States, bacterial meningitis is relatively rare and usually occurs in isolated cases. Clusters of more than a few cases are uncommon.

In parts of Africa, widespread epidemics of meningococcal meningitis occur regularly. In 1996, the biggest wave of meningococcal meningitis outbreaks ever recorded hit West Africa. An estimated 250,000 cases and 25,000 deaths in Niger, Nigeria, Burkina Faso, Chad, Mali, and other countries paralyzed medical care systems and exhausted vaccine supplies.

Is bacterial meningitis an emerging infectious disease?


With the decline in Hib disease, cases of bacterial meningitis have decreased since 1986. Meningococcal meningitis is a continuing threat in day-care centers and schools. Healthy children and young adults are susceptible, and death can occur within a few hours of onset.

How can bacterial meningitis be prevented?


Vaccines -- There are vaccines against Hib, some strains of Neisseria meningitidis, and many types of Streptococcus pneumoniae.

The vaccines against Hib are very safe and highly effective. By age 6 months of age, every infant should receive at least three doses of an Hib vaccine. A fourth dose (booster) should be given to children between 12 and 18 months of age.

The vaccine against Neisseria meningitidis (meningococcal vaccine) is not routinely used in civilians in the United States and is relatively ineffective in children under age 2 years. The vaccine is sometimes used to control outbreaks of some types of meningococcal meningitis in the United States. New meningococcal vaccines are under development.

The vaccine against Streptococcal pneumoniae (pneumococcal vaccine) is not effective in persons under age 2 years but is recommended for all persons over age 65 and younger persons with certain medical problems. New pneumococcal vaccines are under development.

Disease reporting --

Cases of bacterial meningitis should be reported to state or local health authorities so that they can follow and treat close contacts of patients and recognize outbreaks.

Treatment of close contacts --

People who are identified as close contacts of a person with meningitis caused by Neisseria meningitidis can be given antibiotics to prevent them from getting the disease. Antibiotics for contacts of a person with Hib disease are no longer recommended if all contacts 4 years of age or younger are fully vaccinated.

Travel precautions -- Although large epidemics of bacterial meningitis do not occur in the United States, some countries experience large, periodic epidemics of meningococcal disease. Overseas travelers should check to see if meningococcal vaccine is recommended for their destination. Travelers should receive the vaccine at least 1 week before departure, if possible.

Where can I find more information about bacterial meningitis?


Centers for Disease Control

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.

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Meningitis

Definition Return to top

Meningitis is an infection which causes inflammation of the membranes covering the brain and spinal cord. Non-bacterial meningitis is often referred to as "aseptic meningitis." Bacterial meningitis may be referred to as "purulent meningitis."

Causes, incidence, and risk factors Return to top

The most common causes of meningitis are viral infections that usually resolve without treatment. However, bacterial infections of the meninges are extremely serious illnesses, and may result in death or brain damage even if treated. Meningitis is also caused by fungi, chemical irritation or drug allergies, and tumors.

Types include:

meningitis - cryptococcal
syphilitic aseptic meningitis
meningitis - H. influenza
meningitis - meningococcal
meningitis - pneumococcal
meningitis - staphylococcal
meningitis - tuberculous
aseptic meningitis
meningitis gram negative
carcinomatous meningitis (meningitis due to cancer)

Acute bacterial meningitis is a true medical emergency, and requires immediate hospital-based treatment. Bacterial strains that cause meningitis include Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis (meningococcus), Listeria monocytogenes, and many other types of bacteria. In the U.S. about 17,500 cases of bacterial meningitis occur each year.

Viral meningitis is milder and occurs more often than bacterial meningitis. It usually develops in the late summer and early fall, often affects children and adults under 30. Seventy percent of the infections occur in children under the age of 5. Most viral meningitis is associated with enteroviruses, which are viruses that commonly cause stomach flu.

However, many other types of viruses can also cause meningitis; for example, viral meningitis may occur as a complication in people with genital herpes. Recently, West Nile virus spread by mosquito bites has become a cause of viral meningitis in most of the U.S. In addition to causing viral meningitis, West Nile virus can cause encephalitis in some patients and a polio-like syndrome in others.

Symptoms Return to top

fever and chills
severe headache
nausea and vomiting
stiff neck ("meningismus")
sensitivity to light (
photophobia)
mental status changes Additional symptoms that may be associated with this disease:
decreased consciousness
rapid breathing
agitation
opisthotonos (severe neck stiffness, ultimately resulting in a characteristic arched posture-seen in infants or small children)
"bulging fontanelles" may be seen in infants
poor feeding or irritability in children

Meningitis is an important cause of fever in newborn children. For this reason, a lumbar puncture is often done on newborns who have a fever of uncertain origin.

Signs and tests Return to top

Lumbar puncture with CSF glucose measurement and CSF cell count.
Gram-stain and culture of CSF (cerebral spinal fluid).
Chest X-ray to look for other sites of infection.
Head CT scan looking for hydrocephalus, abscess or deep swelling.

Treatment Return to top

Antibiotics will be prescribed for bacterial meningitis; the type will vary depending on the infecting organism. Antibiotics are ineffective in viral meningitis. Treatment of secondary symptoms including brain swelling, shock, and convulsions will require other medications and intravenous fluids. Hospitalization may be required depending on the severity of the illness and the needed treatment.

Expectations (prognosis) Return to top

Early diagnosis and treatment of bacterial meningitis is essential to prevent permanent neurological damage. Viral meningitis is usually not serious, and symptoms should disappear within 2 weeks with no residual complications.

Complications Return to top

hearing loss / deafness
brain damage
loss of vision
hydrocephalus

Calling your health care provider Return to top

If you feel that you or your child have symptoms suggestive of meningitis, you must seek emergency medical help immediately. Early treatment is key to a good outcome.

Prevention Return to top

Haemophilus vaccine (HiB vaccine) in children will help prevent one type of meningitis.
The Pneumococcal Conjugate Vaccine is now a routine childhood immunization and is very effective at preventing pneumococcal meningitis

It is highly recommended that household contacts and individuals with close contact with individuals with meningococcal meningitis receive preventative antibiotics to avoid becoming infected themselves.

Some communities conduct vaccination campaigns following an outbreak of meningococcal meningitis. Military recruits are routinely vaccinated against this form of meningitis because of its high rate of occurrence.

The American Academy of Pediatrics and the American College Health Association encourage college students (particularly freshmen living in dormitories) to consider being vaccinated with the meningococcal vaccine.

Update Date: 1/16/2004

Updated by: Daniel Levy, M.D., Ph.D., Infectious Diseases, Greater Baltimore Medical Center, Baltimore, MD. Review provided by VeriMed Healthcare Network.

Medline Plus

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See Also:

Bacterial Meningitis
eMedicine

Meningitis
Kids Health

Saturday, December 17, 2005

 

Riboswitches may help fight bacterial infection

United Press InternationalFriday, December 16, 2005

NEW HAVEN, Conn., Dec 16, 2005 (UPI via COMTEX) -- The recently emerged field of bacterial riboswitches may help in fighting bacterial infection, Connecticut researchers said.
Riboswitches are RNA elements that control gene expression in essential metabolic pathways.
The riboswitch controlling vitamin B1 -- thiamine -- levels is disrupted in the presence of pyrithiamine, a toxic compound related to the vitamin, said Ronald R. Breaker, the Henry Ford II professor of Molecular, Cellular and Developmental Biology at Yale University.

Bacteria and fungi fail to grow in pyrithiamine and become resistant by acquiring mutations in their riboswitches. This work, in combination with the recently solved crystal structures of purine riboswitches, opens a path to the directed design of drugs targeting riboswitches for use as antibiotics.

The findings are published in the journal

Friday, December 16, 2005

 

MRSA - Methicillin Resistant Staphylococcus Aureus

What is Staphylococcus aureus (staph)?

Staphylococcus aureus, often referred to simply as "staph," are bacteria commonly carried on the skin or in the nose of healthy people. Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose with staph bacteria. Sometimes, staph can cause an infection. Staph bacteria are one of the most common causes of skin infections in the United States. Most of these skin infections are minor (such as pimples and boils) and can be treated without antibiotics (also known as antimicrobials or antibacterials). However, staph bacteria also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia).

What is MRSA (methicillin-resistant Staphylococcus aureus)?

Some staph bacteria are resistant to antibiotics. MRSA is a type of staph that is resistant to antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin. While 25% to 30% of the population is colonized with staph, approximately 1% is colonized with MRSA.


Who gets staph or MRSA infections?

Staph infections, including MRSA, occur most frequently among persons in hospitals and healthcare facilities (such as nursing homes and dialysis centers) who have weakened immune systems. These healthcare-associated staph infections include surgical wound infections, urinary tract infections, bloodstream infections, and pneumonia.


What is community-associated MRSA (CA-MRSA)?

Staph and MRSA can also cause illness in persons outside of hospitals and healthcare facilities. MRSA infections that are acquired by persons who have not been recently (within the past year) hospitalized or had a medical procedure (such as dialysis, surgery, catheters) are know as CA-MRSA infections. Staph or MRSA infections in the community are usually manifested as skin infections, such as pimples and boils, and occur in otherwise healthy people.


How common are staph and MRSA infections?

Staph bacteria are one of the most common causes of skin infection in the United States and are a common cause of pneumonia, surgical wound infections, and bloodstream infections. The majority of MRSA infections occur among patients in hospitals or other healthcare settings; however, it is becoming more common in the community setting. Data from a prospective study in 2003, suggests that 12% of clinical MRSA infections are community-associated, but this varies by geographic region and population.
What does a staph or MRSA infection look like?
Staph bacteria, including MRSA, can cause skin infections that may look like a pimple or boil and can be red, swollen, painful, or have pus or other drainage. More serious infections may cause pneumonia, bloodstream infections, or surgical wound infections.


Are certain people at increased risk for community-associated staph or MRSA infections?

CDC has investigated clusters of CA-MRSA skin infections among athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, men who have sex with men, and prisoners.Factors that have been associated with the spread of MRSA skin infections include: close skin-to-skin contact, openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.


How can I prevent staph or MRSA skin infections?

Practice good hygiene:


Keep your hands clean by washing thoroughly with soap and water or using an alcohol-based hand sanitizer.
Keep cuts and scrapes clean and covered with a bandage until healed.
Avoid contact with other people’s wounds or bandages.
Avoid sharing personal items such as towels or razors.


Are people who are positive for the human immune deficiency virus (HIV) at increased risk for MRSA? Should they be taking special precautions?

People with weakened immune systems, which include some patients with HIV infection, may be at risk for more severe illness if they get infected with MRSA. People with HIV should follow the same prevention measures as those without HIV to prevent staph infections, including practice good hygiene, cover wounds (e.g., cuts or abrasions) with clean dry bandages, avoid sharing personal items such as towels and razors, and contact their doctor if they think they have an infection.


Can I get a staph or MRSA infection at my health club?

In the outbreaks of MRSA, the environment has not played a significant role in the transmission of MRSA. MRSA is transmitted most frequently by direct skin-to-skin contact. You can protect yourself from infections by practicing good hygiene (e.g., keeping your hands clean by washing with soap and water or using an alcohol-based hand rub and showering after working out); covering any open skin area such as abrasions or cuts with a clean dry bandage; avoiding sharing personal items such as towels or razors; using a barrier (e.g., clothing or a towel) between your skin and shared equipment; and wiping surfaces of equipment before and after use.

What should I do if I think I have a staph or MRSA infection?

See your healthcare provider.


Are staph and MRSA infections treatable?

Yes. Most staph and MRSA infections are treatable with antibiotics. If you are given an antibiotic, take all of the doses, even if the infection is getting better, unless your doctor tells you to stop taking it. Do not share antibiotics with other people or save unfinished antibiotics to use at another time.


However, many staph skin infections may be treated by draining the abscess or boil and may not require antibiotics. Drainage of skin boils or abscesses should only be done by a healthcare provider.


If after visiting your healthcare provider the infection is not getting better after a few days, contact them again. If other people you know or live with get the same infection tell them to go to their healthcare provider.


Is it possible that my staph or MRSA skin infection will come back after it is cured?

Yes. It is possible to have a staph or MRSA skin infection come back (recur) after it is cured. To prevent this from happening, follow your healthcare provider’s directions while you have the infection, and follow the
prevention steps after the infection is gone.

If I have a staph, or MRSA skin infection, what can I do to prevent others from getting infected?

You can prevent spreading staph or MRSA skin infections to others by following these steps:


Cover your wound. Keep wounds that are draining or have pus covered with clean, dry bandages. Follow your healthcare provider’s instructions on proper care of the wound. Pus from infected wounds can contain staph and MRSA, so keeping the infection covered will help prevent the spread to others. Bandages or tape can be discarded with the regular trash.

Clean your hands. You, your family, and others in close contact should wash their hands frequently with soap and warm water or use an alcohol-based hand sanitizer, especially after changing the bandage or touching the infected wound.


Do not share personal items. Avoid sharing personal items such as towels, washcloths, razors, clothing, or uniforms that may have had contact with the infected wound or bandage. Wash sheets, towels, and clothes that become soiled with water and laundry detergent. Drying clothes in a hot dryer, rather than air-drying, also helps kill bacteria in clothes.


Talk to your doctor. Tell any healthcare providers who treat you that you have or had a staph or MRSA skin infection.


What should I do if someone I know has a staph or MRSA infection?

If you know someone that has a staph or MRSA infection you should follow the
prevention steps.

For further reading please see the list of References

Date last modified: February 3, 2005

Content source: Division of Healthcare Quality Promotion (DHQP)

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What are the criteria for distinguishing community-associated MRSA (CA-MRSA) from healthcare-associated MRSA (HA-MRSA)?

Persons with MRSA infections that meet all of the following criteria likely have CA-MRSA infections:

Diagnosis of MRSA was made in the outpatient setting or by a culture positive for MRSA within 48 hours after admission to the hospital.

No medical history of MRSA infection or colonization.


No medical history in the past year of:


Hospitalization
Admission to a nursing home, skilled nursing facility, or hospice
Dialysis
Surgery


No permanent indwelling catheters or medical devices that pass through the skin into the body.


What is the main way that staph or MRSA is transmitted in the community?


The main mode of transmission of staph and/or MRSA is via hands which may become contaminated by contact with a) colonized or infected individuals, b) colonized or infected body sites of other persons, or c) devices, items, or environmental surfaces contaminated with body fluids containing staph or MRSA. Other factors contributing to transmission include skin-to-skin contact, crowded conditions, and poor hygiene.

How is a MRSA infection diagnosed?

In general, a culture should be obtained from the infection site and sent to the microbiology laboratory. If S. aureus is isolated, the organism should be tested as follows to determine which antibiotics will be effective for treating the infection.

Skin Infection: Obtain either a small biopsy of skin or drainage from the infected site. A culture of a skin lesion is especially useful in recurrent or persistent cases of skin infection, in cases of antibiotic failure, and in cases that present with advanced or aggressive infections.

Pneumonia: Obtain a sputum culture (expectorated purulent sputum, respiratory lavage, or bronchoscopy).

Bloodstream Infection: Obtain blood cultures using aseptic techniques.

Urinary Infection: Obtain urine cultures using aseptic techniques.

How are CA-MRSA infections treated?

Staph skin infections, such as boils or abscesses, may be treated by incision and drainage, depending on severity. Antibiotic treatment, if indicated, should be guided by the susceptibility profile of the organism.

How do CA-MRSA and HA-MRSA strains differ?

Recently recognized outbreaks of MRSA in community settings have been associated with strains that have some unique microbiologic and genetic properties compared with the traditional hospital-based MRSA strains, suggesting some biologic properties (e.g., virulence factors) may allow the community strains to spread more easily or cause more skin disease.

Additional studies are underway to characterize and compare the biologic properties of HA-MRSA and CA-MRSA strains.

There are at least three different S. aureus strains in the United States that can cause CA-MRSA infections. CDC continues to work with state and local health departments to gather organisms and epidemiologic data from known cases to determine why certain groups of people get these infections.

Are MRSA infections a reportable disease?

MRSA is reportable in several states. The decision to make a particular disease reportable to public health authorities is made by each state, based on the needs of that individual state. To find out if MRSA is reportable in your state, call your state health department.

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METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA)

DermNetNZ

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METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA)

John Hopkins Health

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Antibiotic Selection for Infections Involving Methicillin-Resistant Staphylococcus aureus

John G. Bartlett, MD

Choosing Appropriate Therapy for MRSA

 

Necrotizing Fasciitis

Necrotizing Fasciitis

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Synonyms and related keywords: Fournier's gangrene, Fournier gangrene, Meleney's ulcer, Meleney ulcer, postoperative progressive bacterial synergistic gangrene, flesh-eating bacteria, Cullen's ulcer, Cullen ulcer, hemolytic streptococcal gangrene, acute dermal gangrene, hospital gangrene, suppurative fascitis, synergistic necrotizing cellulitis, group A hemolytic streptococci, Staphylococcus aureus, Bacteroides fragilis, Escherichia coli, nonclostridial myonecrosis, Vibrio vulnificus, diabetes mellitus, fascial necrosis. (1)

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Necrotizing fasciitis is a severe bacterial infection. It is most commonly caused by Group A Strep or a mixture of bacteria including anærobic bacteria. Anærobic bacteria thrive in environments that are poor in oxygen, like wounds. Rarely, bacteria get into the thin membranes called fascia that connect the skin and underlying muscle tissues. In this environment, the bacteria destroy surrounding tissues and can spread rapidly through the body. Such an infection can quickly become deadly.

Necrotizing fasciitis sometimes occurs in people who skin pop or muscle drugs and, more rarely, among intravenous users. The bacteria may come from contaminated dope, from using dirty injection equipment, or from bacteria on your skin. If the bacteria are in the drug itself, you can't depend on "cooking" to kill the bacteria.

This type of infection has been popularized in the press as "flesh-eating" bacteria. While cases are rare in King County, over the past couple years doctors at Harborview Medical Center report treating one to two cases at any given time. Most local cases happen among injection drug users.

How to Protect Yourself

You can reduce your risk for bacterial infections and abscesses.
Use a brand new sterile syringe every time you inject or divide drugs.
Do not re-use syringes.
Do not share syringes, cookers, cottons, mixing or rinse water with anybody.
If you must re-use injecting equipment, clean it thoroughly with bleach.
Click here to learn more about "How to Bleach Your Works in 3 Easy Steps."
Before you inject, clean the injection site with soap and hot water. Really scrub to remove harmful bacteria that may be hanging out on your skin.
If you can't use soap and hot water, clean the site with alcohol wipes before you inject.

What does Necrotising fasciitis look and feel like?

Typical signs of infection are redness, swelling, warmth and tenderness.

With necrotizing fasciitis, skin around an injection site may show redness and swelling OR it may look normal.

The underlying area will feel very tender.

You may have pain, chills, and fever.

At the beginning, it may look like a regular abscess, but it gets worse very quickly. It can cause serious damage under your skin in as little as 12 hours. Necrotizing fasciitis usually MOVES REALLY FAST.

If you have these signs of infection, or the redness or swelling around a wound gets bigger, go to an EMERGENCY ROOM for treatment. Don't try to treat this infection yourself. Bring a copy of this webpage with you.

If Necrotizing fasciitis is caught early, it can be successfully treated. But it is very important to catch it early and begin treatment immediately.

This infection is nothing to play around with. If you do not get medical care early, you run the risk of losing skin, losing an arm, or even death.

MetroKCHealth

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Necrotizing soft tissue infection

Alternative names

Necrotizing fasciitis; Fasciitis - necrotizing; Flesh-eating bacteria; Soft tissue gangrene; Gangrene - soft-tissue

Definition

Necrotizing soft-tissue infection is a severe type of tissue infection that can involve the skin, subcutaneous fat, the muscle sheath (fascia), and the muscle. It causes gangrenous changes, tissue death, systemic disease, and frequently death.

Causes, incidence, and risk factors

Necrotizing subcutaneous infection or fasciitis can be caused by a variety of bacteria including oxygen-using bacteria (aerobic) or oxygen-avoiding bacteria (anaerobic). A very severe and usually fatal fasciitis is caused by a virulent species of streptococcus that is often referred to as the "flesh-eating bacteria" by the press.This type of infection develops when bacteria enter the body, usually through a minor skin injury or abrasion.

The bacteria begin to grow and release toxins that:

Directly kill tissue
Interfere with the blood flow to the tissue
Digest materials in the tissue which then allows the bacteria to spread rapidly
Cause widespread effects, such as
shock

Infection may begin as a small reddish painful spot or bump on the skin. This quickly changes to a painful bronzed or purplish patch that expands rapidly. The center may become black and dead (necrotic). The skin may break open. Visible expansion of the infection may occur in less than an hour.

Symptoms may include fever, sweating, chills, nausea, dizziness, profound weakness, and finally shock. Without treatment death can occur rapidly.

Symptoms

Severe pain in the area
Swelling in the area
Discoloration in the area
May appear reddened, bronzed, bruised, or purple (purpuric)
Progresses to dusky, dark color
Bleeding into the skin
Visibly dead (necrotic) tissue
Patchy skin color
Skin breaks (open wound)
Skin around the wound feels hot and looks reddened, raised, or discolored (inflamed)
Oozing fluid ranging from yellowish clear or yellowish bloody to puslike in quality
Fever
General ill feeling

Signs and tests

The appearance of the skin and underlying tissues and presence of gangrenous changes (black or dead tissue) indicates a necrotizing soft tissue infection. Imaging tests, such as CT scans, are sometimes helpful.

Often a patient will need to go to the operating room so a surgeon can diagnose such an infection. A Gram stain and culture of drainage or tissue from the area may reveal the bacteria to blame.

Treatment

Powerful, broad-spectrum antibiotics must be administered immediately. They are given in a vein to attain high blood levels of the antibiotic in an attempt to control the infection. Surgery is required to open and drain infected areas and remove dead tissue.

Skin grafts may be required after the infection is cleared. If the infection is in a limb and cannot be contained or controlled, amputation of the limb may be considered. Sometimes pooled immunoglobulins (antibodies) are given by vein to help fight the infection.If the organism is determined to be an oxygen-avoiding bacteria (anaerobe) the patient may be placed in a hyperbaric oxygen chamber, a device in which the patient is exposed to 100% oxygen at several atmospheres of pressure.

Expectations (prognosis)

Outcomes are variable. The type of infecting organism, rate of spread, susceptibility to antibiotics, and how early the condition was diagnosed all contribute to the final outcome.
Scarring and deformity are common with this type of disease. Fatalities are high even with aggressive treatment and powerful antibiotics. Untreated, the infection invariably spreads and causes death.

Complications

local spread of infection, progressive tissue damage
systemic spread of infection, sepsis, shock
scarring and disfigurement
functional loss of a limb
death

Calling your health care provider

This disorder is severe and may be life-threatening, so consult your health care provider immediately.Call your health care provider if signs of infection occur around a skin injury: pain, swelling, redness, drainage of pus or blood, fever, or other similar symptoms.

Prevention

Clean any skin injury thoroughly. Watch for signs of infection such as redness, pain, drainage, swelling around the wound, and consult the health care provider promptly if these occur.

Update Date: 1/16/2004

Medline Plus

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Health Canada

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Necrotizing Fasciitis

eMedicine

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Necrotizing Fasciitis (Flesh-Eating Bacteria)

Webmd

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National Necrotizing Fasciitis Foundation

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Google Diagnostic Images


 

Bacterial Contamination of Vegetables and Fruits

Vegetables And Fruits Cause More US Food Illnesses

Reuters Health

By Susan Heavey

Tuesday, November 22, 2005

WASHINGTON (Reuters) - Contaminated fruits and vegetables are causing more food-borne illness among Americans than raw chicken or eggs, consumer advocates said in a report released on Monday.

Common sources of food illnesses include various bacteria such as salmonella and Escherichia coli that can infect humans and animals and then make their way into manure used to fertilize plants. The practice of using manure fertilizer is more common in Latin America, which has become a growing source of fresh produce for the United States.

"Although poultry has historically been responsible for far more Salmonella infections, in the most recent years...produce seems to be catching up," the Center for Science in the Public Interest (CSPI) said, calling for tougher federal food safety standards.

Vegetables and fruits triggered 31 outbreaks from 2002 to 2003, compared with 29 for chicken and other poultry, according to the report.

Overall, contaminated tomatoes, sprouts and other produce made 28,315 people sick during 554 outbreaks from 1990 to 2003 -- 20 percent of all cases CSPI analyzed.

Chicken made 14,729 people sick in 476 outbreaks, and eggs were responsible for 10,847 illnesses from 329 outbreaks, according to the group.

"Pathogens can adhere to the rough surfaces of fruits and vegetables, so consumers should take precautions, such as washing produce under running water," the report said, adding people should "still eat plenty of produce."

Food-related infections cause a range of problems from discomfort to severe dehydration and death, but most problematic organisms can be killed when food is cooked long enough at high enough temperatures.

Not all people exposed to the bacteria get sick, but those who do can experience vomiting, diarrhea and fever, among other problems for as long as a week. Some experience no symptoms but can infect others.

The report found seafood was the largest cause of outbreaks but led to fewer illnesses than other foods. There have been 899 such outbreaks between 1990 and 2003, leading to 9,312 illnesses.

CSPI officials urged federal regulators to do more to protect the nation's food supply -- a job currently divided among at least 10 U.S. agencies, including the Food and Drug Administration and the Department of Agriculture.

One large, independent agency would reduce coordination troubles, conflicting standards and other problems that make the government slow to act, the group said.

Other changes could be made in the meantime, it added.

"FDA should require growers to limit the use of manure to times and products where it poses no risk. And packers and shippers should mark packaging to ensure easy traceback when fruits and vegetables are implicated in an outbreak," said Caroline Smith DeWaal, CSPI's food safety director.

CSPI's database includes reports mostly from the Centers for Disease Control and Prevention. Other sources, including state health departments and medical journals, make up 7 percent of the data.


 

Abortion Pill and Bacterial Infections - Study

New York Times Syndicate

By Diedtra Henderson Globe Staff

Wednesday, November 30, 2005

WASHINGTON - An article in Thursday's New England Journal of Medicine could increase pressure on the Food and Drug Administration to restrict the sale of abortion pills associated with four fatal infections in California.

The FDA in September 2000 approved Mifeprex - also called RU-486 and known generically as mifepristone. It is used with a second drug, misoprostol, to induce early-stage abortions.

But as early as 1992, scientists warned mifepristone could make women vulnerable to massive bacterial infections. Some doctors have routinely defied FDA recommendations by advising women to administer misoprostol vaginally. Some researchers say that could transport bacteria near the uterus, where they can grow unchecked.

Thursday's article says four young, otherwise healthy women in California died from such bacterial infections soon after using RU-486 and misoprostol.

Conservative politicians and abortion foes have already been pressuring the FDA to take RU-486 off the market. The agency said it will convene a meeting to attempt to determine if there is a connection between the abortion pill and the fatal infections.

A Canadian woman also died from the infection. The deaths, out of about 510,000 medical abortions involving RU-486, while rare, amount to a roughly 1 in 100,000 risk of developing a fatal bacterial infection. That compares with a 0.1 in 100,000 risk for women who undergo surgical abortions performed at the same stage of pregnancy, according to the Journal article.

Danco Laboratories, which manufactures Mifeprex, said the fatal infections were not caused by its drug. Nor does vaginal administration of misoprostol increase the risk of infection, said Cynthia Summers, a Danco spokeswoman.

Days after using Mifeprex and misoprostol, the women complained of abdominal pain and vomiting. Without the typical warning sign of fever, a rare bacteria - Clostridium sordellii - multiplied inside their bodies, pumping out toxins. Within hours of seeking medical treatment, the women were dead.

A team of medical sleuths who investigate unexplained deaths studied clues from the women's tissues - in one case, performing an autopsy after a woman had been embalmed - according to Thursday's Journal.

"I think, for women, the take-home message just is that this is a now known, rare complication with this medication and they should be aware of that," Dr. Marc Fischer, a Centers for Disease Control researcher who was lead author of the article.

When the FDA approved Mifeprex, it did so with its strongest label warning.

The label has since been updated to include information about other serious complications.

In the Journal article, 13 federal and state investigators described a cluster of symptoms that physicians should watch for - including elevated heart rate, markedly elevated white blood cell counts, higher-than-normal red blood counts and eventual development of low blood pressure.

These deaths have important implications both for the care of individual patients and for public policy," said Dr. Michael F. Greene, obstetrics director at Massachusetts General Hospital, in an editorial in Thursday's Journal.

"Regulators should keep this rare complication in perspective and not overreact to scant data by prematurely foreclosing the only approved medical option for pregnancy termination," wrote Greene, an obstetrics, gynecology and reproductive biology professor at Harvard Medical School and occasional federal adviser.

The FDA has faced a growing number of critics who say the agency bungled oversight of antidepressants and safety problems posed by Bextra and Vioxx, painkillers that ultimately were pulled from the market. More recently, Democratic leaders accused the FDA of putting politics above science regarding the emergency contraception known as Plan B. The agency has yet to decide whether women can buy the morning-after pill without a prescription.

"Obviously, they're sort of running scared after the whole Vioxx thing and other high-profile withdrawals where they've been accused of being slow to respond - or responding inadequately to an apparent threat to the public health," Greene said.

But a leading French ethicist, who said his daughter was one of the women who died in California, wonders whether the FDA could better help doctors and patients. The man's daughter, a 34-year-old mother of two, died five days after her medical abortion, according to a letter published in the December issue of The Annals of Pharmacotherapy. Her earliest symptoms - abdominal pain and bleeding - appeared to be typical side effects from such abortions.

"Lack of awareness of the severity of the situation at this moment is dangerous," wrote Didier Sicard, the deceased woman's father, and Dr. Laurence Chauvelot-Moachon, of Hospital Cochin in Paris.

It may be "useful" to give women who undergo medical abortions antibiotics that work against C. sordellii before, during, and after taking the pills, they wrote.

The FDA has not recommended such preventive antibiotic use.

An American microbiologist who first linked tampons to fatal toxic shock syndrome said vaginal administration of misoprostol should be prohibited because it can increase infection risk.

"That may, in and of itself, eliminate the problem," said Philip M.
Tierno, director of clinical microbiology and immunology at New York University Medical Center.

An FDA spokeswoman said the safety and effectiveness of misoprostol administered vaginally "have not been established."

Diedtra Henderson can be reached at dhendersonglobe.com


Wednesday, December 14, 2005

 

Study Links Infections with Some Childhood Cancers

Study Links Infections with Some Childhood Cancers

Reuters HealthMonday, December 12, 2005

LONDON (Reuters) - Common infections that affect mothers and babies may trigger certain types of childhood cancers, researchers said on Monday.
They found that leukemia and brain tumors, leading cancers in children, occurred in clusters, which suggests that outbreaks of infections are a contributing cause of the disease.

"We found that place of birth was particularly significant, which suggests that an infection in the mother while she is carrying her baby, or in a child's early years, could be a trigger factor for the cancer," said Dr. Richard McNally, of the University of Newcastle upon Tyne in northern England.

"These could be minor, common illnesses...such a cold, mild flu or a respiratory infection," he added in a statement.

McNally and a team of researchers from England and Scotland, who reported the findings in the European Journal of Cancer, said the results could improve understanding about how cancer develops and may lead to better prevention and treatment.

Although cancer in children is rare, rates of the disease in youngsters in Europe have increased over the past three decades. Survival rates however have improved. Five-year survival rates are about 75 percent in western Europe and 63 percent in eastern Europe.

Leukemia is the most common childhood cancer, accounting for nearly one third of all cases. Most of the rise has been in children ages 1 to 4.

The researchers believe an infection in the womb or early in life could lead to cancer in young people who carry mutant cells that would make them more vulnerable to the disease.

"The virus would hit this mutant cell and cause a second mutation, prompting the onset of cancers like leukemia or brain tumors," said McNally.

The findings are based on a statistical analysis of data from the Manchester Children's Tumour Register, which recorded all cases of childhood cancers diagnosed between January 1954 and December 1998.

They looked for unusual patterns of cancer linked to the time and place of children's birth and where they were living when diagnosed with cancer.
In some clusters they found 8 percent more cases of leukemia than would normally be expected and a 13 percent above-average incidence of the brain tumour astrocytoma.

"These findings provide more clues to a link between viruses and some types of childhood cancer, but we need more evidence before we can be sure," said Professor John Toy, of the charity Cancer Research UK, which funded the research.


Monday, December 12, 2005

 

Cure nears for flesh-eating bug

Scientists in Newcastle claim they are closer to developing a cure for some of the world's most deadly diseases.

Northumbria University researchers say the discovery could cure toxic shock syndrome, septicaemia and the flesh-eating necrotizing faciitis.

The drug-resistant diseases are caused by streptococcus bacterium, which is more common now than 10 years ago.

Scientists say they are closer to discovering why the bug, which also causes sore throats, can kill.
Dr Gary Black and a team from the university's school of applied sciences, used a technique similar to DNA testing to isolate one of the many enzymes within the bacterium, which is thought to be responsible for triggering some of the diseases.


Saving lives

He discovered that the enzyme has a rare triple-stranded beta-helix shape, which is similar to only four other enzymes out of the thousands tested in recent years.

Dr Black, 39, from County Durham, now hopes one of the world's leading pharmaceutical companies will take up his research and use his findings to develop revolutionary life-saving drugs.

He said: "This is a major breakthrough which has the potential to save thousands of lives in the future."

His findings are published in Proceedings of the National Academy of Sciences of the United States of America - one of the world's most cited multidisciplinary scientific journals.

BBC News

 

Deadly bacterial illness appears to be spreading

Deadly bacterial illness appears to be spreading: CDC report

Canadian PressThursday, December 1, 2005

ATLANTA (CP) - A deadly bacterial illness commonly seen in people on antibiotics appears to be growing more common - even in patients not taking such drugs, federal health officials warned Thursday.
The bacteria are Clostridium difficile, also known as C-diff. The germ is becoming a regular menace in hospitals and nursing homes.


One study estimates that as many as 2,000 people may have died in Quebec in 2003-2004 because of C. difficile infection, according to the Canadian Medical Association Journal.
Recent cases in four U.S. states show it is appearing more often in healthy people who have not been admitted to health-care facilities or even taken antibiotics, according to Centers for Disease Control and Prevention.


"What exactly has made C-diff act up right now, we don't know," said Dr. L. Clifford McDonald, a CDC epidemiologist.

C-diff is found in the colon and can cause diarrhea and a more serious intestinal condition known as colitis. It is spread by spores in feces. But the spores are difficult to kill with conventional household cleaners.

C-diff has grown resistant to certain antibiotics that work against other colon bacteria. The result: when patients take those antibiotics, particularly clindamycin, competing bacteria die off and C-diff explodes.

The CDC report focused on 33 cases reported since 2003.

Twenty-three involved otherwise healthy people in the Philadelphia area who were not admitted to a hospital within three months of illness. Ten more were otherwise healthy pregnant women or women who had recently given birth who had had brief hospital stays. Those reports came from Pennsylvania, Ohio, New Jersey and New Hampshire.

One of the 33 patients died - a 31-year-old Pennsylvania woman who was 14 weeks pregnant with twins when she first went to the emergency room with symptoms. Despite treatment with antibiotics considered effective against C-diff, she lost the fetuses and then died.

She had been treated about three months earlier for a urinary tract infection with an antibiotic, trimethoprim-sulfamethoxazole. Ten others among the 33 patients had taken clindamycin.
But in eight of the 33 cases, patients said they had not taken any antibiotics within three months of the onset of symptoms.


Doctors watching for C-diff in hospitals and nursing home patients need to look for it in other patients as well, McDonald said. Patients need to be wary too. "If you have severe diarrhea, seek attention from a physician," he said.

Thursday, December 08, 2005

 

Clostridium Difficile

By: Charalabos Pothoulakis, M.D., Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.

Clostridium difficile, or C. difficile (a gram-positive anaerobic bacterium), is now recognized as the major causative agent of colitis (inflammation of the colon) and diarrhea that may occur following antibiotic intake. C. difficile infection represents one of the most common hospital (nosocomial) infections around the world. In the United States alone, it causes approximately three million cases of diarrhea and colitis per year. This bacterium is primarily acquired in hospitals and chronic care facilities following antibiotic therapy covering a wide variety of bacteria (broad-spectrum) and is the most frequent cause of outbreaks of diarrhea in hospitalized patients. One of the main characteristics of C. difficile-associated colitis is severe inflammation in the colonic tissue (mucosa) associated with destruction of cells of the colon (colonocytes).

The disease involves, initially, alterations of the beneficial bacteria, which are normally found in the colon, by antibiotic therapy. The alterations lead to colonization by C. difficile when this bacterium or its spores are present in the environment. In hospitals or nursing home facilities where C. difficile is prevalent and patients frequently receive antibiotics, C. difficile infection is very common. In contrast, individuals treated with antibiotics as outpatients have a much smaller risk of developing C. difficile infection. Laboratory studies show that when C. difficile colonize the gut, they release two potent toxins, toxin A and toxin B, which bind to certain receptors in the lining of the colon and ultimately cause diarrhea and inflammation of the large intestine, or colon (colitis). Thus, the toxins are involved in the pathogenesis, or development of the disease.

Transmission Factors - An important characteristic of C. difficile-associated diarrhea and colitis is its high prevalence among hospitalized patients. Thus, C. difficile contributes significantly to hospital length of stay, and may be associated in some elderly adults with chronic diarrhea, and occasionally other serious or potentially life-threatening consequences. One study demonstrated that 20% of patients admitted to a hospital for various reasons were either positive for C. difficile on admission or acquired the microorganism during hospitalization. Interestingly, only one-third of these patients developed diarrhea while the remainder were asymptomatic carriers serving as a reservoir of C. difficile infection. The organism and its spores were also demonstrated in the hospital environment, including toilets, telephones, stethoscopes, and hands of healthcare personnel.

While patient-to-patient spread and environmental contamination can be some of the reasons of cross-infection in C. difficile-associated diarrhea and colitis, antibiotic therapy is the major risk factor for this disease. Thus, antibiotic use only when necessary is the most effective measure of preventing C. difficile infection.

Clinical Features - A wide range of conditions is associated with C. difficile infection. Most cases develop 4 to 9 days after the beginning of antibiotic intake. It should be noted, however, that some patients develop diarrhea after antibiotics are discontinued and this may lead to diagnostic confusion. Although nearly all antibiotics have been implicated with the disease, the commonest antibiotics associated with C. difficile infection are ampicillin, amoxicillin, cephalosporins, and clindamycin.

The most common presentation is either mild colitis, or simple diarrhea that is watery and contains mucus but not blood. Examination by sigmoidoscopy usually reveals normal colonic tissue. General symptoms are commonly absent and diarrhea usually stops when antibiotics are discontinued. C. difficile can also cause non-specific colitis quite reminiscent of other intestinal bacterial infections such as Shigella or Campylobacter. This is a more serious illness than simple antibiotic-associated diarrhea; patients experience watery diarrhea 10 to 20 times a day and lower, crampy abdominal pain. Low-grade fever, dehydration, and non-specific colitis are common manifestations.

Pseudomembranous colitis represents the characteristic manifestation of full-blown C. difficile-associated colitis. Sigmoidoscopic examination reveals the presence of characteristic plaque-like pseudomembranes, scattered over the colonic tissue. The presence of these plaques is a distinctive indicator of C. difficile infection in patients with diarrhea following antibiotic treatment.

The most serious manifestation of C. difficile infection, fulminant colitis (severe sudden inflammation of the colon), is frequently associated with very serious complications. This can be a life-threatening form of C. difficile infection and occurs in 3% of patients; most are elderly and debilitated from other diseases. Patients with this form of the disease experience severe lower abdominal pain, diarrhea, high fever with chills, and rapid heart beat. Timely treatment of fulminant colitis is essential; this condition can be life threatening.

C. difficile infection in patients with other intestinal diseases - It is well documented that C. difficile may complicate the course of ulcerative colitis or Crohn's disease and it is responsible for 4 to 12% of diarrhea in AIDS patients. In this case, patients develop the typical symptoms of C. difficile colitis, including diarrhea, abdominal pain, and fever reminiscent of exacerbation of inflammatory bowel disease. The reason for this complication is not entirely clear. It may be that the frequent hospitalizations and exposure to antibiotics of patients with inflammatory bowel disease or AIDS places them at increased risk for the infection. So far there is no evidence to indicate that C. difficile can complicate the symptoms associated with irritable bowel syndrome (IBS).
Laboratory Diagnosis - The laboratory diagnosis of C. difficile infection is primarily related to the demonstration of C. difficile toxins in the stool of suspected patients. The detection of C. difficile toxins in the stool can be made by a laboratory test (cytotoxicity assay) where the toxins can be easily observed in the microscope. This tissue culture assay is considered the gold standard because of its high sensitivity and specificity. Since there is no correlation between levels of C. difficile toxins in the stool and severity of the disease, the results are reported simply as "positive" or "negative." However, time is a drawback of this assay since it requires 24 to 48 hours to read the results.

Over the past few years several rapid tests that take just a few hours, and which do not require specialized personnel to run, have been developed (immuno-enzymatic assays) for the detection of C. difficile toxins in the stool. These tests are commercially available in the form of diagnostic kits. Although they are relatively less sensitive and demonstrate lower specificity compared to the laboratory tests, they are very useful not only in the every day practice when specialized personnel is not available, but also in emergency situations and in rapid screening of patients during spreading of the disease in hospitals.

Therapy - Therapy of C. difficile is directed against eradication of the microorganism from the colonic microflora. No therapy is required for asymptomatic carriers. In noncomplicated patients with mild diarrhea, no fever, and modest lower abdominal pain, discontinuation of antibiotics (if possible) is often enough to alleviate symptoms and stop diarrhea. When severe diarrhea is present and in cases of established colitis, the patients should receive the antibiotics, metronidazole or vancomycin, for 10 to 14 days. Several clinical trials have shown that these antibiotics are equally effective in cases of mild to moderate C. difficile infection and more than 95% of patients respond very well to this treatment. Diarrhea following treatment with either vancomycin or metronidazole is expected to improve after 1 to 4 days with complete resolution within 2 weeks. However, some patients do not respond despite aggressive medical therapy and require surgical intervention.

Therapy for relapsing C. difficile infection - Although C. difficile infection usually responds well to treatment with metronidazole or vancomycin, approximately 15 to 20% of patients will experience re-appearance of diarrhea and other symptoms weeks or even months after initial therapy has been discontinued. The usual therapy for relapse is to repeat the 10 to 14 day course of either metronidazole or vancomycin and this is successful in most patients. However, a subset of patients continues to relapse whenever antibiotics are discontinued and this represents a therapeutic challenge. Some authorities recommend switching to the alternative antibiotic from the one used initially. A variety of other therapies have also been described for relapsing disease. It is hoped that development of vaccines against C. difficile toxins may someday control the problem of C. difficile infection in hospitals

aboutibs

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Clostridium difficile FAQs

It seemed to come out of nowhere – a virulent strain of bacteria called Clostridium difficile. It picked up that name because when it was first discovered, it was difficult to grow in the lab.

C. difficile is not an uncommon bacterium – but it had some infectious disease specialists worrying that it has become the most dangerous superbug to hit North American hospitals in a decade. In October 2004, researchers found that 7,000 people had been infected with C. difficile in Montreal since 2003, and at least 600 of them died. Hospitals in Ottawa and Calgary have also experienced periodic outbreaks.

What is C. difficile?

C. difficile bacteria grow in the large bowel. They thrive in the stool compressed inside the colon. The bacteria produce two toxins that cause diarrhea and damage the cells lining the bowel. However, not all strains of C. difficile produce toxin. These strains are unlikely to cause disease and patients colonized by them remain healthy.

In severe cases, C. difficile can cause critical illness and death in elderly or very sick patients.

Why are health care officials concerned?

The experts investigating the outbreak say the bacterium appears to have mutated into a highly contagious and lethal strain – and they don't know why. It has caused almost four times the usual number of cases of severe diarrhea in hospitals, and can persist in the body for months despite repeated antibiotic treatments.

Doctors know C. difficile flourish after patients take certain antibiotics. Now it seems any antibiotic can bring on the disease.

"Something happened 18 to 24 months ago, where the use of particular antibiotics didn't seem to matter anymore," said Dr. Mark Miller, chief of infectious diseases at Montreal's Jewish General Hospital.

How do I get it?

The bacteria are almost exclusively picked up in hospital. Infections tend to arise when a hospitalized patient – who has been unwittingly colonized by the bug – is given antibiotics for another condition.

Your risk of contracting the bacteria rises if you're undergoing chemotherapy, have abdominal surgery or have other stomach or intestine problems.

C. difficile bacteria also make spores that can be found in the environment – on toilet seats or doorknobs, for instance.

How does it spread?

If you get diarrhea from C. difficile infection, you can spread the bacteria by touching something – like a doorknob – if you haven't washed your hands. The spores produced by C. difficile can withstand the effects of drying and direct sunlight and survive on surfaces for weeks.

When someone else comes in contact with those spores and touches their hand to their face, for instance, the spores can get into the gastro-intestinal tract and cause diarrhea.

How is it treated?

Even though the bacteria are sometimes triggered when a patient takes antibiotics, the most effective treatments are certain antibiotics. Short courses – three to five days – of antibiotics such as flagyl and vancomycin are most common. In some cases, doctors also inject patients with immunoglobulins to boost their immune systems.

How is the spread of C. difficile controlled?

Infected patients are often separated from non-affected patients. Hospital staff who deal with infected patients will wear disposable gloves and aprons.

Areas that patients come in contact with are rigorously cleaned with warm water and detergent to remove spores that can spread the condition.

The most efficient way to prevent person-to-person spread of C. difficile is to thoroughly wash your hands before and after patient contact.

What should I do if I'm caring for someone affected by C. difficile?

Wash your hands often:
Before you eat or prepare food.


After you use the toilet or handle a bedpan.

Before and after you touch a person with C. difficile.

More tips:

If you must handle stool, wear rubber gloves.

Clean the washroom daily.


Put disposable wastes – like diapers – into plastic bags, tie them and discard with the rest of the trash.

If clothes are heavily soiled with stool, wash them separately with detergent and bleach. Do not mix with the rest of your laundry.

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