Spatial distribution of Legionella pneumophila MLVA-genotypes in a drinking water system

Abstract

14Bacteria of the genus Legionella cause water-based infections, resulting in severe pneumonia. 15To improve our knowledge about Legionella spp. ecology, its prevalence and its relationships 16 with environmental factors were studied. Seasonal samples were taken from both water and 17 biofilm at seven sampling points of a small drinking water distribution system in Israel. 18Representative isolates were obtained from each sample and identified to the species level. L. water. This observation deserves further studies in a broad range of drinking water systems to 34 assess its potential for general use in drinking water monitoring and management.

Temperature-Dependent Growth Modeling of Environmental and Clinical Legionella pneumophila Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Genotypes

“…In a yearly survey, we (19) demonstrated that different sites along a water network were dominated by different genotypes (for more details, see Fig. 7 in the study by Rodriguez-Martinez et al [19] and Table 1 in the current article).…”

“…Sites with the lowest temperature range (ϳ21°C) harbored Gt4 and had Legionella counts of up to 1 or 2 orders of magnitude higher than Legionella counts at the other sites. Gt15 was dominant at sites with high temperatures (45°C) but with lower Legionella counts than at the other sites (19). This effect of temperature on the survival, growth, and prevalence of the different genotypes at the different drinkingwater distribution sites (Table 1) deserves extensive investigation and was addressed in the present study.…”

“…Genotyping is epidemiologically important for recognizing the sources of infections and is needed to track L. pneumophila strains from the environment to clinical material or isolates from specific patients or, more importantly, to identify outbreak strains (18). Recent work by our group (19) showed that to obtain insight into the ecological traits of L. pneumophila in drinking-water systems, the level of genotypes (analyzed by MLVA-8: see below) has to be addressed. In a yearly survey, we (19) demonstrated that different sites along a water network were dominated by different genotypes (for more details, see Fig.…”

“…Recent work by our group (19) showed that to obtain insight into the ecological traits of L. pneumophila in drinking-water systems, the level of genotypes (analyzed by MLVA-8: see below) has to be addressed. In a yearly survey, we (19) demonstrated that different sites along a water network were dominated by different genotypes (for more details, see Fig. 7 in the study by Rodriguez-Martinez et al [19] and Table 1 in the current article).…”

“…Analysis of environmental and microbiological parameters at the sites of Legionella isolation of the three dominant genotypes (Gt4, Gt6, and Gt15) (Table 1) demonstrated that they could be addressed as different ecotypes with very distinct temperature and abundance ranges at the sites of their occurrence (for more details, see Table 6 in reference 19). Sites with the lowest temperature range (ϳ21°C) harbored Gt4 and had Legionella counts of up to 1 or 2 orders of magnitude higher than Legionella counts at the other sites.…”