ABSTRACT
Routine surveillance in a cardiovascular ward showed that the incidence of Enterobacter cloacae isolated from sputum and oropharyngeal cultures in June 2004 increased to 27.6% (8/29) compared to 5.5% (12/219) from the rest of the hospital during the same period (OR=13.2; 95% CI 2.97-58.7; P<0.05). While an increase in E. cloacae pneumonia was not verified, an investigation was undertaken by the infection control team to prevent an outbreak. The estimate of relative risk for E. cloacae infection was based on a case-control study which measured exposure to intubation, history of a stay in the intensive care unit (ICU) and oral care between patients with E. cloacae and those negative for E. cloacae. An odds ratio of 13.2 suggested cross-contamination via the transoesophageal echocardiography (TOE) probe in the ICU prior to transfer to the cardiovascular ward. Pulsed-field gel electrophoresis and antibiogram patterns were also consistent with this hypothesis. Intervention was undertaken in the form of enforcing the disinfection of TOE probes using a 0.55% phtharal solution and the use of a single-use sheath to protect the probe from recontamination. Following intervention, the incidence rate returned to previous levels. This report illustrates the limitations in the effectiveness of current nosocomial surveillance strategies due to the retrospective nature of analysis. Improved surveillance methods such as data-mining tools specifically applicable to the institution, patient population, region and country are needed to increase the sensitivity of detecting unrecognized outbreaks, including cross-contamination.
Subject(s)
Coronary Care Units , Cross Infection/epidemiology , Cross Infection/microbiology , Enterobacter cloacae/isolation & purification , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/microbiology , Equipment Contamination , Case-Control Studies , Cross Infection/transmission , DNA Fingerprinting , DNA, Bacterial/genetics , Disinfection , Echocardiography, Transesophageal/instrumentation , Electrophoresis, Gel, Pulsed-Field , Enterobacter cloacae/classification , Enterobacteriaceae Infections/transmission , Genotype , Hospitals , Humans , Incidence , Infection Control/methods , Intensive Care Units , Intubation , Japan/epidemiology , Length of Stay , Microbial Sensitivity Tests , Oropharynx/microbiology , Phenotype , Risk Factors , Sputum/microbiologyABSTRACT
RAISUS is a system for rapid bacterial identification and antimicrobial susceptibility testing. RAISUS and VITEK showed 97.8% and 75.9% agreement in identification of 45 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CoNS), respectively, and RAISUS and CLSI (formerly NCCLS) methods showed 87.2% and 87.9% agreement in the MICs for S. aureus and CoNS, respectively. RAISUS provided these data within 3.75 h, suggesting its utility for clinical bacteriological laboratories.
Subject(s)
Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests/methods , Staphylococcus aureus/drug effects , Automation , Enzymes , Evaluation Studies as Topic , Fluorescence , Humans , Oxidation-Reduction , Sensitivity and Specificity , Staphylococcal Infections/microbiologyABSTRACT
Incineration of infectious waste is considered to be biologically safe. We performed basic experiments to confirm that bacillus spores are killed by incineration in a muffle furnace. Biological samples containing 10(6) spores of Bacillus stearothermophilus were placed in stainless steel Petri dishes and then into hot furnaces. The furnace temperature and duration of incineration were 300 degrees C for 15 min, 300 degrees C for 30 min, 500 degrees C for 15 min, 500 degrees C for 30 min and 1100 degrees C for 3 min. We confirmed that all spores of B. stearothermophilus were killed at each of these settings. The effect of incineration seems to be equivalent to that of sterilization, based on the satisfactory sterilization assurance level of 10(-6).
