Isolation of mycobacteria from indoor swimming pools in Finland

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140

112

Drinking water distribution systems were analyzed for viable counts of mycobacteria by sampling water from waterworks and in different parts of the systems. In addition, loose deposits collected during mechanical cleaning of the main pipelines were similarly analyzed. The study covered 16 systems at eight localities in Finland. In an experimental study, mycobacterial colonization of biofilms on polyvinyl chloride tubes in a system was studied. The isolation frequency of mycobacteria increased from 35% at the waterworks to 80% in the system, and the number of mycobacteria in the positive samples increased from 15 to 140 CFU/liter, respectively. Mycobacteria were isolated from all 11 deposits with an accumulation time of tens of years and from all 4 deposits which had accumulated during a 1-year follow-up time. The numbers of mycobacteria were high in both old and young deposits (medians, 1.8 ؋ 10 5 and 3.9 ؋ 10 5 CFU/g [dry weight], respectively). Both water and deposit samples yielded the highest numbers of mycobacteria in the systems using surface water and applying ozonation as an intermediate treatment or posttreatment. The number and growth of mycobacteria in system waters correlated strongly with the concentration of assimilable organic carbon in the water leaving the waterworks. The densities of mycobacteria in the developing biofilms were highest at the distal sites of the systems. Over 90% of the mycobacteria isolated from water and deposits belonged to Mycobacterium lentiflavum, M. tusciae, M. gordonae, and a previously unclassified group of mycobacteria. Our results indicate that drinking water systems may be a source for recently discovered new mycobacterial species.

Section: Methodsmentioning

confidence: 99%

Mycobacteria in Water and Loose Deposits of Drinking Water Distribution Systems in Finland

Torvinen

Suomalainen

Lehtola

et al. 2004

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112

“…However, in most of these instances, water is proposed as a possible common vehicle of transmission. These bacteria have been isolated from treated drinking water (9,25,35), hospital and clinic water systems (44), water supplies in hemodialysis centers (6,16), and various other sites, including dental units (34), ice machines (15,24), swimming pool and hot tub water (12,19,27), metalworking fluid (28,36), and aerosols generated during the dismantling of moisture-damaged buildings (43). This group of mycobacteria is heterogeneous in terms of epidemiology, clinical disease spectrum, and drug susceptibility and is now considered a group of emerging waterborne pathogens.…”

mentioning

confidence: 99%

Diversity of Environmental Mycobacterium Isolates from Hemodialysis Water as Shown by a Multigene Sequencing Approach

Gomila

Ramírez

Lalucat

2007

Here we used a multigene sequencing approach for the identification and molecular typing of environmental mycobacteria of the fast-growing subgroup. Strains were isolated from hemodialysis water and clinical samples. Eleven type strains of related species of the genus were also included in this study. To gain further insight into the diversity of the environmental mycobacteria, we analyzed several housekeeping genes (16S rRNA, ITS1, gyrB, hsp65, recA, rpoB, and sodA). No individual phylogenetic tree allowed good discrimination of all of the species studied. However, a concatenated and a consensus analysis, combining the genes, allowed better discrimination of each strain to the species level, and the increase in sequence size also led to greater tree robustness. This approach is useful not only for the discrimination and identification of environmental mycobacteria but also for their molecular typing and studies of population genetics. Our results demonstrate high genetic diversity among the isolates obtained, which are probably new species of the genus.

“…However, there is a subset of patients who develop pulmonary disease without an obvious immune defect or a defect that is yet to be defined. Nontuberculous mycobacteria (NTM) have been demonstrated to be present in drinking water (1,8,11,12,15,16,18,26,35), drinking water distributions systems (17,18,23,(32)(33)(34), hot water systems (4), spas (6), and pools (14,19). However, several authors have failed to identify NTM in water samples, often because of unsuitable isolation techniques.…”

mentioning

confidence: 99%

Comparison of Methods for Processing Drinking Water Samples for the Isolation of Mycobacterium avium and Mycobacterium intracellulare

Thomson

Carter²,

Gilpin³

et al. 2008

Several protocols for isolation of mycobacteria from water exist, but there is no established standard method. This study compared methods of processing potable water samples for the isolation of Mycobacterium avium and Mycobacterium intracellulare using spiked sterilized water and tap water decontaminated using 0.005% cetylpyridinium chloride (CPC). Samples were concentrated by centrifugation or filtration and inoculated onto Middlebrook 7H10 and 7H11 plates and Lowenstein-Jensen slants and into mycobacterial growth indicator tubes with or without polymyxin, azlocillin, nalidixic acid, trimethoprim, and amphotericin B. The solid media were incubated at 32°C, at 35°C, and at 35°C with CO 2 and read weekly. The results suggest that filtration of water for the isolation of mycobacteria is a more sensitive method for concentration than centrifugation. The addition of sodium thiosulfate may not be necessary and may reduce the yield. Middlebrook M7H10 and 7H11 were equally sensitive culture media. CPC decontamination, while effective for reducing growth of contaminants, also significantly reduces mycobacterial numbers. There was no difference at 3 weeks between the different incubation temperatures.