Monday, August 27, 2012
Update on bacterial nosocomial infections.
Update on bacterial nosocomial infections.
Source
Abstract
Labels: antimicrobial, drug resistance, Enterococci, escherichia coli, gram negative, gram positive, hospital infection, nosocomial infections, pathogens, Pseudomonas aeruginosa, Staphylococcus aureus
Saturday, November 22, 2008
Surgical site infections: epidemiology, microbiology and prevention.
J Hosp Infect. 2008 Nov
Owens CD, Stoessel K.
Kimberly-Clark Healthcare, Atlanta, GA, USA.
Surgical site infections (SSIs) are defined as infections occurring up to 30 days after surgery (or up to one year after surgery in patients receiving implants) and affecting either the incision or deep tissue at the operation site. Despite improvements in prevention, SSIs remain a significant clinical problem as they are associated with substantial mortality and morbidity and impose severe demands on healthcare resources. The incidence of SSIs may be as high as 20%, depending on the surgical procedure, the surveillance criteria used, and the quality of data collection. In many SSIs, the responsible pathogens originate from the patient's endogenous flora. The causative pathogens depend on the type of surgery; the most commonly isolated organisms are Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus spp. and Escherichia coli. Numerous patient-related and procedure-related factors influence the risk of SSI, and hence prevention requires a 'bundle' approach, with systematic attention to multiple risk factors, in order to reduce the risk of bacterial contamination and improve the patient's defences. The Centers for Disease Control and Prevention guidelines for the prevention of SSIs emphasise the importance of good patient preparation, aseptic practice, and attention to surgical technique; antimicrobial prophylaxis is also indicated in specific circumstances. Emerging technologies, such as microbial sealants, offer the ability to seal and immobilise skin flora for the duration of a surgical procedure; a strong case therefore exists for evaluating such technologies and implementing them into routine clinical practice as appropriate.
PMID: 19022115 [PubMed - as supplied by publisher]
Labels: coagulase-negative staphylococci, Enterococcus spp, epidemiology, escherichia coli, microbiology, prevention, Staphylococcus aureus, Surgical site infections
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 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
Tuesday, February 06, 2007
Bacterial isolates from severe infections and their antibiotic susceptibility patterns in Italy: a nationwide study in the hospital setting.
Bacterial isolates from severe infections and their antibiotic susceptibility patterns in Italy: a nationwide study in the hospital setting.
J Chemother. 2006 Dec;18
Nicoletti G,
Schito G,
Fadda G,
Boros S,
Nicolosi D,
Marchese A,
Spanu T,
Pantosti A,
Monaco M,
Rezza G,
Cassone A,
Garaci E,
Gruppo Cooperativo Infezioni Gravi Ed Antibiotico Resistenza FT.
The most frequent agents of severe bacterial infections and their antibiotic susceptibility patterns were determined in patients admitted to 45 Italian hospitals over the years 2002-2003. The most common diagnoses were: sepsis (33.8%), pneumonia (9.4%), intravascular catheter-associated infections (9.3%) and ventilator-associated pneumonia (8.1%). Overall, 5115 bacterial isolates were identified from 4228 patients. Three bacterial species, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, accounted for more than 50% of the isolates. Other prevalent bacterial isolates were Staphylococcus epidermidis and Enterococcus faecalis, while Acinetobacter baumanii ranked third among all Intensive Care Unit (ICU) isolates. 7% of S. aureus had intermediate resistance to vancomycin. Although E.faecalis displayed no vancomycin resistance, 34% of vancomycin-resistant isolates were found among Enterococcus faecium, one of the highest rates found to date, emphasizing the difference between these two enterococcal species. All the Gram-positive pathogens were susceptible to linezolid, with the exception of approximately 2% of the enterococcal isolates that were intermediate with a minimum inhibitory concentration (MIC)=4 microg/ml. Almost 10% of Escherichia coli, 14% of Klebsiella pneumoniae, 22% of Serratia marcescens and 50% of Enterobacter cloacae were non-susceptible to cefotaxime. Amikacin was the most active antibiotic against P. aeruginosa that showed lack of susceptibility to ceftazidime, gentamicin, piperacillin and ciprofloxacin ranging from 20 to 35%. Finally, Acinetobacter baumanii showed a high level of resistance to all the antibiotics tested including imipenem (58%). The results obtained in this study, the first of its kind in Italy, offer indications for guiding empirical therapy and implementing specific interventions to fight antibiotic-resistant bacterial infections and their transmission in the hospital setting in Italy.
PMID: 17267336 [PubMed - in process]
Labels: acinetobacter, cefotaxime, ciprofloxan, enterococcus, escherichia coli, gentamicin, klebsiella pneumoniae, p.aeruginosa, piperacillan, staphylococcus epidermidis, vancomycin
