Sunday, April 29, 2007
Pseudomonas aeruginosa kills six babies in Canada
April 28, 2007
Montreal's Ste-Justine Hospital has confirmed that six premature babies who died three years ago in it were infected from bacteria found in a poorly maintained plumbing system, according to Canadian media reports Saturday.
The reports said that about 50 babies had contracted pseudomonas aeruginosa. Four of them, all born prematurely, died. The deaths of two other babies may also have been caused by the bacteria.
The bacterium typically targets the respiratory system, causing pneumonia and septicemia. The premature babies in the neo-natal ward are particularly vulnerable because of their already compromised immune systems.
After the first baby died in 2004, the hospital disinfected the crowded ward and searched for the source of the bacterium but over the next 18 months, five more babies died.
The hospital closed the ward in December 2005 and discovered that the bacterium was breeding in the ward's sinks, which were not draining properly, the reports showed.
The hospital replaced its aging plumbing system and built a new neo-natal ward to open next year.
Ste-Justine said the situation is now under control and there have been no deaths in the last two years.
Quebec Health Minister Philippe Couillard, under fire for this scandal, insisted Friday the public was never at risk.
Sainte-Justine is Quebec's only health care establishment exclusively dedicated to children, adolescents and mothers.
NewsLabels: premature baby, Pseudomonas aeruginosa
Thursday, April 26, 2007
Prediction of specific pathogens in patients with sepsis
J Antimicrob Chemother. 2007 Apr
Paul M, Nielsen AD, Goldberg E, Andreassen S, Tacconelli E, Almanasreh N, Frank U, Cauda R,
Leibovici L.
Department of Medicine E, Rabin Medical Center, Beilinson Campus, Petah-Tiqva 49100, Israel.
Background
Prediction of bacterial infections and their pathogens allows for early, directed investigation and treatment. We assessed the ability of TREAT, a computerized decision support system, to predict specific pathogens. Methods TREAT uses data available within the first few hours of infection presentation in a causal probabilistic network to predict sites of infection and specific pathogens. We included 3529 patients (920 with microbiologically documented infections) participating in the observational and interventional trials of the TREAT system in Israel, Germany and Italy.
Discriminatory performance of TREAT to predict individual pathogens was expressed by the AUC with 95% confidence intervals. Calibration was assessed using the Hosmer-Lemeshow goodness-of-fit statistic. Results The AUCs for Gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella spp. and Escherichia coli, ranged between 0.70 and 0.80 (all significant). Adequate calibration was demonstrated for any Gram-negative infection and individual bacteria, except for E. coli.
Discrimination and calibration were acceptable for Enterococcus spp. (AUC 0.71, 0.65-0.78), but not for Staphylococcus aureus (AUC 0.63, 0.55-0.71). The few infections caused by Candida spp. and Clostridium difficile were well predicted (AUCs 0.74, 0.54-0.95; and 0.94, 0.88-1.00, respectively). The coverage with TREAT's recommendation exceeded that observed with physicians' treatment for all pathogens, except Candida spp.
Conclusions TREAT predicted individual pathogens causing infection well. Prediction of S. aureus was inferior to that observed with other pathogens. TREAT can be used to triage patients by the risk for specific pathogens. The system's predictions enable it to prescribe appropriate antibiotic treatment prior to pathogen identification.
PMID: 17449883 [PubMed - as supplied by publisher]
Labels: Acinetobacter baumannii, escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, sepsis, Staphylococcus aureus, TREAT
Friday, April 20, 2007
Bacterial enzyme and cystic fibrosis
Bacterial Enzyme a clue to cystic fibrosis
Published: April 19, 2007 at 3:33 PM
PHILADELPHIA April 19 (UPI) -- The discovery of a bacterial enzyme infecting lungs may hold the key to new treatments for some cystic fibrosis patients, say U.S. researchers.
A team at the University of Pennsylvania found that the bacterial enzyme spingomyelinase (SMase)shuts down a lung protein called cystic fibrosis transmembrane conductance regulator.
CFTR is found in the bacteria that cause pneumonia, some types of anthrax and the opportunistic infections that occur in CF and AIDS, the researchers noted.
In healthy lungs, CFTR helps chloride ions and water cross lung cell membranes and create a thin layer of fluid to keep the airways clear. CFTR is defective in people with cystic fibrosis, so the mucus in their lungs is thicker than normal, the researchers said.
When bacteria that produce SMase enter the lungs, they break down the protective lipid barrier that surrounds CFTR, causing airway mucus to thicken even more and provide a fertile breeding ground for bacteria. The byproducts of the lipid breakdown also trigger inflammation and cell death.
Most people with CF die of lung infections, but clinicians have been puzzled because CF symptoms and infections were often more severe than the patient's CF genetic mutations warranted, the team said.
But finding SMase has cleared up this mystery, the researchers noted, adding that a combination of SMase enzyme inhibitors, antibiotics and supportive measures might improve the length and quality of life of many CF patients.
A report on the research appears in the April issue of the Proceedings of the National Academy of Sciences.
Labels: bacterial enzyme, CF, CFTR, cystic fibrosis, cystic fibrosis transmembrane conductance regulator
Monday, April 16, 2007
Helicobacter pylori Detection and Antimicrobial Susceptibility Testing.
Clin Microbiol Rev. 2007 Apr
Megraud F,
Lehours P.
Laboratoire de Bacteriologie, Hopital Pellegrin, Place Amelie Raba-Leon, 33076 Bordeaux cedex, France. francis.megraud@chu-bordeaux.fr.
The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed.
Clinical Microbiology Reviews
Labels: Helicobacter pylori
Friday, April 13, 2007
Streptococcal impetigo at topical tacrolimus application sites in a woman with atopic dermatitis.]
Ann Dermatol Venereol. 2007 Mar
Reynaert G,
Rey AC,
Graveriau C,
Hesse S,
Denoeux JP.
Service de Dermatologie et Venereologie, CHU, Groupe hospitalier sud, Amiens.
BACKGROUND: We report a case of staphylococcal impetigo in a girl treated with tacrolimus ointment (Protopic(R)) for atopic dermatitis.
OBSERVATION: A 15 year-old girl was receiving treatment with tacrolimus 0.03% (Protopic(R)) for an episode of atopic dermatitis. On reduction of applications of tacrolimus, a vesicular-pustular rash appeared and was treated with pristinamycin and valaciclovir. At the end of antibiotic and antiviral therapy, the vesicular-pustular rash recurred while the goal was receiving treatment once more with tacrolimus ointment 0.1%. The bacteriological and virological skin samples revealed B-haemolytic streptococcus group A. The negative results for cutaneous virological samples ruled out Kaposi-Juliusberg syndrome and a diagnosis of staphylococcal impetigo was made. The intrinsic imputability of tacrolimus was I3 (C3 S2).
DISCUSSION: The most obvious specific feature of this impetigo was its limitation to areas of eczema treated by application of tacrolimus. In prospective studies in large patient cohorts, tacrolimus ointment has been associated with two types of adverse effect: local irritations and skin infections chiefly caused by Staphylococcus aureus. To date, there have been no reports in the literature of impetigo due to haemolytic B streptococcus following application of tacrolimus. Because of its immunodepressant effect, tacrolimus ointment may result in increased incidence of skin infections even though a number of studies have shown a reduction in such infections.
Masson
Labels: atopic dermatitis, impetigo, pristinamycin, Staphylococcus aureus, tacrolimus, valaciclovir
Friday, April 06, 2007
Targeted drug-carrying bacteriophages as anti bacterial nanomedicines.
Antimicrob Agents Chemother. 2007 Apr 2
Department of Molecular Microbiology and Biotechnology, The George S. wise faculty of Life Sciences, and Department of Organic Chemistry School of Chemistry, Tel-Aviv University, Ramat Aviv 69978, Israel.
While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, anti bacterial targeted therapy could provide an opportunity to re-introduce toxic substances to the anti-bacterial arsenal. A desirable targeted anti-bacterial agent should combine binding specificity, a large drug payload per binding event and a programmed drug release mechanism. Recently we presented a novel application of filamentous bacteriophages as targeted drug carriers that could partially inhibit the growth of Staphylococcus aureus bacteria.
This partial success was due to limitations of drug-loading capacity that resulted from the hydrophobicity of the drug. Here we present a novel drug conjugation chemistry which is based on connecting hydrophobic drugs to the phage via aminoglycoside antibiotics that serve as solubility-enhancing branched linkers. This new formulation allowed a significantly larger drug-carrying capacity of the phages resulting in a drastic improvement in their performance as targeted drug carrying nanoparticles. As an example for a potential systemic use for potent agents that are limited for topical use, we present antibody-targeted phage nanoparticles that carry a large payload of the hemolytic antibiotic chloramphenicol connected through the aminoglycoside neomycin.
We demonstrate complete growth inhibition towards the pathogens Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli with an improvement in potency by a factor of approximately 20,000 as compared to the free drug.
Antimicrobial Agents and Chemotherapy
Labels: anti bacterial nanomedicines, bacteriophages, escherichia coli, Staphylococcus aureus, Streptococcus pyogenes
