title: Cooccurrence of free-living amoebae and nontuberculous Mycobacteria in hospital water networks, and preferential growth of Mycobacterium avium in Acanthamoeba lenticulata.
abstract: The incidence of lung and other diseases due to nontuberculous mycobacteria (NTM) is increasing. NTM sources include potable water, especially in households where NTM populate pipes, taps, and showerheads. NTM share habitats with free-living amoebae (FLA) and can grow in FLA as parasites or as endosymbionts. FLA containing NTM may form cysts that protect mycobacteria from disinfectants and antibiotics. We first assessed the presence of FLA and NTM in water and biofilm samples collected from a hospital, confirming the high prevalence of NTM and FLA in potable water systems, particularly in biofilms. Acanthamoeba spp. (genotype T4) were mainly recovered (8/17), followed by Hartmannella vermiformis (7/17) as well as one isolate closely related to the genus Flamella and one isolate only distantly related to previously described species. Concerning mycobacteria, Mycobacterium gordonae was the most frequently found isolate (9/17), followed by Mycobacterium peregrinum (4/17), Mycobacterium chelonae (2/17), Mycobacterium mucogenicum (1/17), and Mycobacterium avium (1/17). The propensity of Mycobacterium avium hospital isolate H87 and M. avium collection strain 104 to survive and replicate within various FLA was also evaluated, demonstrating survival of both strains in all amoebal species tested but high replication rates only in Acanthamoeba lenticulata. As A. lenticulata was frequently recovered from environmental samples, including drinking water samples, these results could have important consequences for the ecology of M. avium in drinking water networks and the epidemiology of disease due to this species.
authors.affiliation: National Jewish Health, Denver, CO, USA.
authors.forename: Alida R
authors.initials: AR
authors.lastname: Ovrutsky
authors.forename: Edward D
authors.initials: ED
authors.lastname: Chan
authors.forename: Marinka
authors.initials: M
authors.lastname: Kartalija
authors.forename: Xiyuan
authors.initials: X
authors.lastname: Bai
authors.forename: Mary
authors.initials: M
authors.lastname: Jackson
authors.forename: Sara
authors.initials: S
authors.lastname: Gibbs
authors.forename: Joseph O
authors.initials: JO
authors.lastname: Falkinham
authors.forename: Michael D
authors.initials: MD
authors.lastname: Iseman
authors.forename: Paul R
authors.initials: PR
authors.lastname: Reynolds
authors.forename: Gerald
authors.initials: G
authors.lastname: McDonnell
authors.forename: Vincent
authors.initials: V
authors.lastname: Thomas
mesh_terms: D000048:Acanthamoeba / Q000302:isolation & purification / Q000382:microbiology*; D018441:Biofilms; D018920:Coculture Techniques; D060766:Drinking Water / Q000382:microbiology / Q000469:parasitology; D017753:Ecosystem; D006249:Hartmannella / Q000302:isolation & purification / Q000382:microbiology; D006761:Hospitals; D050296:Microbial Viability; D009162:Mycobacterium avium / Q000254:growth & development* / Q000302:isolation & purification; D009170:Nontuberculous Mycobacteria / Q000254:growth & development / Q000302:isolation & purification*; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D060766:Drinking Water