You are here:
IDENTIFICATION AND CHARACTERIZATION OF AEROMONAS ISOLATES FROM DRINKING WATER DISTRIBUTION SYSTEMS
Citation:
Birkenhauer, J. M. AND M R. Rodgers. IDENTIFICATION AND CHARACTERIZATION OF AEROMONAS ISOLATES FROM DRINKING WATER DISTRIBUTION SYSTEMS. Presented at American Society for Microbiology, Washington, DC, May 18-22, 2003.
Impact/Purpose:
Investigate the occurrence of Aeromonas bacteria in potable water derived from both surface and ground water sources. Develop improved method(s) for the detection of culturable H. pylori in environmental samples and investigate the occurrence of H. pylori in potable waters.
Description:
Members of the bacterial genus Aeromonas are commonly isolated from both fresh and salt waters worldwide and some are believed to cause infections in humans, including gastroenteritis and wound infections. Currently, aeromonads are on the United States Environmental Protection Agency's Contaminant Candidate List, and are suspected of contaminating drinking water distribution systems. Identification of aeromonads to the species level is difficult as new species, taxa, and biogroups continue to be proposed. In this study, we employ both metabolic and genomic fingerprinting identification methods to obtain an understanding of the occurrence and types of aeromonads in drinking water distribution systems in the US.
Water samples were analyzed from 18 drinking water distribution systems across the US, eight of which were found to contain aeromonads. All colonies were isolated from ADA-V medium and were confirmed to be aeromonads as recommended in EPA Method 1605. Confirmed isolates, 212 in total, were then subjected both a Restriction Fragment Length Polymorphism (RFLP) analysis (Borrell et al, 1997) and to a carbon source utilization assay employing the BIOLOG microbial identification system.
The BIOLOG microbial identification system offers a straightforward approach to identifying environmental microbes. However, we found that only after compiling our own database were we able to gain confidence in the system's ability to correctly identify each isolate. The RFLP analysis, while requiring much more time and technical skill, was able to give a more consistent identification of each isolate, with the exception to certain biotypes.
Based on both the metabolic and genomic fingerprinting of these organisms we were able to identify several different biotypes, including A. hydrophila, A. bestiarum, and A. salmoncida from drinking water distribution systems. Since some of the species that were isolated have been implicated in human disease, the results from this study indicate that a more comprehensive survey of drinking water utilities is warranted to determine if aeromonads in drinking water pose a threat to public health.