In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from...In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from hospital facilities for the mentally disabled. The strains were selected after a retrospective surveillance of 565 clinical records （2002-2009） and investigations of water circuit. It was possible to correlate two clinical strains with the corresponding environment, which were collected from showers that had exposed the patients （ST685, ST16） and two clinical strains present in the same structure （STI）. The other environmental strains were isolated from water in the department with confirmed or suspected clinical cases. All the strains （seven） from the first structure had ST188; two from the second structure had ST34; and the last from the third structure, gave an ST694. The results were compared with the European Working Group for Legionella Infections （EWGLI） database： the ST 1, 16, 34 and 188 were already known in literature, among clinical and nosocomial cases, especially for ST 1, the most distributed worldwide. Two STs were new to the database. ST685 was isolated both from a patient and from the water; ST694, which was found exclusively in the environmental compartment of a control structure （no cases of legionellosis and low number of nosocomial pneumonia）, was unknown in the literature and the authors could only speculate on its possible minor virulence and/or distribution. The implementation of SBT and international comparisons may be useful to gain genotypic knowledge of circulating environmental strains, also verifying their presence in the clinical setting.展开更多
文摘In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from hospital facilities for the mentally disabled. The strains were selected after a retrospective surveillance of 565 clinical records （2002-2009） and investigations of water circuit. It was possible to correlate two clinical strains with the corresponding environment, which were collected from showers that had exposed the patients （ST685, ST16） and two clinical strains present in the same structure （STI）. The other environmental strains were isolated from water in the department with confirmed or suspected clinical cases. All the strains （seven） from the first structure had ST188; two from the second structure had ST34; and the last from the third structure, gave an ST694. The results were compared with the European Working Group for Legionella Infections （EWGLI） database： the ST 1, 16, 34 and 188 were already known in literature, among clinical and nosocomial cases, especially for ST 1, the most distributed worldwide. Two STs were new to the database. ST685 was isolated both from a patient and from the water; ST694, which was found exclusively in the environmental compartment of a control structure （no cases of legionellosis and low number of nosocomial pneumonia）, was unknown in the literature and the authors could only speculate on its possible minor virulence and/or distribution. The implementation of SBT and international comparisons may be useful to gain genotypic knowledge of circulating environmental strains, also verifying their presence in the clinical setting.
