Molecular epidemiology of Legionella pneumophila environmental isolates representing nine different serogroups determined by automated ribotyping and pulsed-field gel electrophoresis

• Published in: Epidemiology and infection Vol. 133; no. 6; pp. 1097 - 1105
• Main Authors: BOCCIA, S., STENICO, A., AMORE, R., MORODER, L., ORSINI, M., ROMANO-SPICA, V., RICCIARDI, G.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01-12-2005
• Subjects: Bacteriology; Biological and medical sciences; DNA; Electrophoresis; Electrophoresis, Gel, Pulsed-Field; Environmental Microbiology; Epidemiology; Fundamental and applied biological sciences. Psychology; Gels; Hospital buildings; Legionella; Legionella pneumophila; Legionella pneumophila - classification; Legionella pneumophila - genetics; Legionnaires' Disease - epidemiology; Legionnaires' Disease - microbiology; Microbiology; Miscellaneous; Molecular Epidemiology; Nursing homes; Ribotyping; Serotyping; Water Microbiology; Water samples; Human; Pulsed field electrophoresis; Ribotype; Legionellaceae; Microbiology; Molecular epidemiology; Bacteria; Environment; Genotype; Isolate; Legionella pneumophila
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268805004395

The purposes of the study were (i) to describe the abundance and epidemiology of Legionellaceae in the man-made environment in a northern Italian area, (ii) to assess the concordance between pulsed-field gel electrophoresis (PFGE) and automated ribotyping (AR) techniques for genotyping L. pneumophila and (iii) to investigate the correlation between serogrouping and genotyping data. Water was sampled from reservoirs in 12 buildings across an area of 80-km radius. Despite the water temperature always being maintained above 55 °C, all of the buildings sampled were contaminated with Legionellaceae on at least one occasion and 63 L. pneumophila isolates representing nine different serogroups were collected. The two DNA methods revealed a high degree of genetic heterogeneity, even though identical L. pneumophila clones were recovered at different sites. The AR technique provided a fairly reliable approximation of PFGE results (73% concordance), however there was poor correlation between serogrouping and genotyping data as identical DNA fingerprints were shared by isolates of different serogroups.