WRRC Seminar: A Roadmap for Best Practices in Microbial Risk Assessment of Water

Yong Jin Lee Postdoctoral Research Associate Institute for Environmental Genomics University of Oklahoma

Rapid detection and concurrent identification of pathogens are important, especially for early identification of potential threats to public health in water. As molecular biological techniques emerged, many molecular methods have been developed for detecting new emergent strains and indicators as well as specific pathogens. Since conventional methods used to monitor microbial contamination cannot discriminate among the various contamination sources impacting a body of water, microbial source-tracking (MST) methods have been developed and tested in field applications.

Using culture-independent host-specific PCR assays, we surveyed various rural watersheds and streams and showed a combination of 16S rRNA gene andnon-16S rRNA gene probes could provide a higher level of confidence for tracking unknown sources of fecalpollution.

However, these MST methods relied on a limited number of genetic markers that were designed for a particular indicator or a group. Thus, it is necessary to develop molecular methods that directly detect and identify waterborne pathogens in a quantitative and highthroughput manner. We developed a functional gene array constructed with key virulence genesrelated to 13 major virulence factors. This arraycontains 3,715 best probes, covering 7,417 coding sequences from 1,397 microbial species (2,336strains). The specificity of the array was computationally verified, and then applied to community samples from oil-contaminated seawater.Statistical analyses showed both abundance and diversity of the virulence genes significantly increased in oil-contaminated seawater.

This array provides a powerful tool for detecting a broad range of pathogenicmicrobial populations, examining the dynamics of virulence gene in response to environmental perturbations, and assessing microbial risk in diverse environments.

For better assessment of microbial water quality,the WaterChip, amore specific and comprehensive functional gene array, is currently under development.

Event Sponsor
Water Resources Research Center, Manoa Campus

More Information
Philip Moravcik, 956-3097, morav@hawaii.edu, http://www.wrrc.hawaii.edu/seminars.php

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