Molecular Epidemiology of Nosocomial Infection Caused by Methicillin-Resistant Staphylococcus aureus

点击翻译按钮获取中文摘要

In epidemiologic studies of MRSA nosocomial infection, phage types, coagulase types, antibiotic patterns, or biological features have been used. We conduct epidemiologic studies of clinically isolated MRSA strains, using molecular biological techniques with DNA analysis.In order to clarify details of actual nosocomial infections, the frequency of MRSA isolation and the incidence of MRSA infection in inpatients of the Nagoya University Hospital are investigated and the genotype of isolated MRSA is determined by pulsed-field gel electrophoresis.Moreover, the genotypes of 563 MRSA strains collected from national university hospitals were also determined to study the regional differences of MRSA spread.These genotypes were summarized and a DNA typing system, a computerized catalog of isolated MRSA strains, was created. Use of this system enables comparison of bacteria among the hospitals or between Japan and other countries as well as comparison of bacteria within the hospital.The degree of pathogenesis differs according to each MRSA strain. Especially, strains isolated from patients with severe MRSA infection were examined carefully to determine whether or not there were characteristic genotypes in those strains. The strains causing severe MRSA infection such as sepsis in the Nagoya University Hospital were concentrated to several genotypes. The strains causing postoperative severe enteritis in other hospitals were also certain genotypes. It will become possible to take preventive measures if MRSA strains which may cause severe infection from the genotypes can be known in advance.