[Epidemiological study on nosocomial infection of Pseudomonas cepacia by plasmid analyses]

In order to clarify the usefulness of plasmid analyses in epidemiological study, plasmid DNA profiles, restriction fragment patterns of chromosomal DNA analysed by pulsed-field gel electrophoresis (PFGE), and patterns of extracellular products were performed in twenty-four nosocomial strains of Pseudomonas cepacia isolated at the Kagawa Medical School Hospital. Fifteen strains were obtained from 15 patients admitted in A ward, three strains were obtained from nebulizer devices used in A ward, 5 strains were obtained from 5 patients admitted in B ward, and 1 strain was obtained from a patient admitted in C ward. Three different patterns which differed from ward to ward were clearly distinguished by PFGE patterns and patterns of extracellular products. On the other hand, plasmid DNA profiles were different in some strains obtained from B ward. These results suggested that plasmid analyses combined with other typing methods are useful in more precise epidemiological analysis on nosocomial infection of P. cepacia.