Free-living amoebae, Legionella and Mycobacterium in tap water supplied by a municipal drinking water utility in the USA

Legionella and Mycobacterium can proliferate within free-living amoebae (FLA) where they are protected from disinfectants at concentrations that can kill bacteria but not protozoa. Despite effective treatment of drinking water, microbes can enter water utility distribution systems (DS) and hence the...

Full description

Saved in:
Bibliographic Details
Published in:Journal of water and health 2010-03, Vol.8 (1), p.71-82
Main Authors: Marciano-Cabral, Francine, Jamerson, Melissa, Kaneshiro, Edna S
Format: Article
Language:English
Subjects:
Acanthamoeba
Amoebida - isolation & purification
Animals
Bacteria
Biofilms
Cities
Culture media
Deoxyribonucleic acid
Disinfectants
DNA
DNA probes
Domestic water
Drinking water
Dynamics
Electron microscopy
Health risks
Humans
Legionella
Legionella - isolation & purification
Mycobacterium
Mycobacterium - isolation & purification
Naegleria
Opportunist infection
Pathogenic bacteria
Plumbing
Population structure
Probes
Proliferation
Protozoa
Public health
Seasons
Spring
System effectiveness
United States
Vahlkampfia
Water - parasitology
Water Microbiology
Water Supply
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Legionella and Mycobacterium can proliferate within free-living amoebae (FLA) where they are protected from disinfectants at concentrations that can kill bacteria but not protozoa. Despite effective treatment of drinking water, microbes can enter water utility distribution systems (DS) and hence the plumbing within building premises. Additionally, biofilm formation may account for the persistence of microbes in the DS. In the present study a domestic water tap in north-central United States (USA) was sampled in March and September 2007 and analysed for FLA, Legionella and Mycobacterium. Identification of organisms was determined by growth on specific culture media, light and electron microscopy, and amplification of DNA probes specific for each organism. In both the spring and fall samples, amoebae, Legionella and Mycobacterium were detected. However, Acanthamoeba was prominent in the spring sample whereas Vahlkampfia and Naegleria were the amoebae detected in the autumn. Bacterial proliferation in laboratory cultures was noticeably enhanced in the presence of amoebae and biofilms rapidly formed in mixed amoebae and bacteria cultures. It is hypothesized that temperature affected the dynamics of FLA species population structure within the DS and that pathogenic bacteria that proliferate within FLA, which are themselves opportunistic pathogens, pose dual public health risks.
ISSN:1477-8920
1996-7829
DOI:10.2166/wh.2009.129