Diversity, Community Composition, and Dynamics of Nonpigmented and Late-Pigmenting Rapidly Growing Mycobacteria in an Urban Tap Water Production and Distribution System

Abstract

e Nonpigmented and late-pigmenting rapidly growing mycobacteria (RGM) have been reported to commonly colonize water production and distribution systems. However, there is little information about the nature and distribution of RGM species within the different parts of such complex networks or about their clustering into specific RGM species communities. We conducted a large-scale survey between 2007 and 2009 in the Parisian urban tap water production and distribution system. We analyzed 1,418 water samples from 36 sites, covering all production units, water storage tanks, and distribution units; RGM isolates were identified by using rpoB gene sequencing. We detected 18 RGM species and putative new species, with most isolates being Mycobacterium chelonae and Mycobacterium llatzerense. Using hierarchical clustering and principal-component analysis, we found that RGM were organized into various communities correlating with water origin (groundwater or surface water) and location within the distribution network. Water treatment plants were more specifically associated with species of the Mycobacterium septicum group. On average, M. chelonae dominated network sites fed by surface water, and M. llatzerense dominated those fed by groundwater. Overall, the M. chelonae prevalence index increased along the distribution network and was associated with a correlative decrease in the prevalence index of M. llatzerense, suggesting competitive or niche exclusion between these two dominant species. Our data describe the great diversity and complexity of RGM species living in the interconnected environments that constitute the water production and distribution system of a large city and highlight the prevalence index of the potentially pathogenic species M. chelonae in the distribution network. N onpigmented and late-pigmenting rapidly growing mycobacteria (RGM) are ubiquitous in soil and water environments (1-6). Most are harmless saprophytes, but some, such as Mycobacterium chelonae and Mycobacterium abscessus, are opportunistic pathogens that are causing increasing concern (7-9). Potentially pathogenic RGM are associated with a wide spectrum of diseases in humans, including pulmonary tract, skin, soft tissue, and disseminated infections (10-14), mostly in patients with predisposing conditions (e.g., lung diseases, chronic obstructive pulmonary disease, cystic fibrosis, genetic predisposition, or immunosuppressive therapy). Contamination and hypersensitive reactions are often due to environmental exposure (associated with, for example, hot tubs, metalworking fluids, or contaminated dust) (15-19), and many outbreaks following invasive medical procedures have been reported over the last decade (20-25). Tap water may be an important source of contamination in urban environments (13,18,(26)(27)(28)(29)(30).RGM are commonly recovered from water treatment and distribution systems (31-38), probably because they can form biofilms (2, 39-41) and resist chlorination and oligotrophic conditions (42,43). Mycobacterium chelonae and Mycobact...

Microbiological Features and Clinical Relevance of New Species of the Genus Mycobacterium

“…The strains on which the species nova description is based were isolated from hemodialysis water in a hospital in Majorca, Spain, and other reports subsequently documented the isolation of M. llatzerense from tap water (48,57). Two clinical cases were recently reported, one in the United States, concerning a liver transplant recipient with pulmonary disease (58), and one case of abdominal abscess, in Spain (59).…”

Two Rapidly Growing Mycobacterial Species Isolated from a Brain Abscess: First Whole-Genome Sequences of Mycobacterium immunogenum and Mycobacterium llatzerense

“…The patient's subacute course was characterized by headache and visual changes, her history of sinopulmonary infections, and the fact that the coisolated bacterial species are common constituents of both upper airway and oropharyngeal flora, suggesting an initial respiratory source of inoculation. Several rapidly growing mycobacterial species, including M. llatzerense and M. immunogenum, have been isolated from water sources, suggesting potential water exposure to the mycobacterium species ultimately isolated from the abscess (13)(14)(15). However, environmental cultures were not available to investigate this possibility.…”

Abdominal Abscess Caused by Mycobacterium llatzerense

“…This rapidly growing mycobacterium was initially found in hemodialysis water in a hospital in Mallorca, Spain (3), and was then described in tap and shower water in two homes in the Netherlands (8), in the Parisian urban tap water production and distribution system (9), and in tap water from a skilled nursing facility in Pennsylvania (10). There has also been one case of invasive pneumonia attributed to M. llatzerense, identified by PCR from paraffin-embedded lung tissue, but in which no organism was recovered (11).…”