Field, K. Oregon State University, fieldk@bcc.orst.edu
Bernhard, A. Oregon State University, bernhara@bcc.orst.edu
Barry, A. Oregon State University, barrya@ucs.orst.edu

 
GENETIC MARKERS FROM ANAEROBIC BACTERIA USED TO DISCRIMINATE HUMAN AND CATTLE FECAL CONTAMINATION OF ESTUARINE WATERS WITHOUT CULTURING INDICATOR ORGANISMS
 
Current methods using fecal coliforms to monitor fecal pollution do not provide reliable means to distinguish between human and animal sources. We tested the use of 16S rRNA markers from Bacteroides and Bifidobacterium, anaerobes comprising a significant percentage of mammalian fecal flora, to distinguish sources of fecal pollution in coastal waters. We developed our markers using DNAs from human and cow fecal samples and sewage effluent. PCR products resulting from group-specific amplifications were analyzed by RFLP, Length Heterogeneity PCR (LH-PCR), and T-RFLP (terminal restriction fragment length polymorphism), utilizing GeneScan (Applied BioSystems), which separates amplified fragments by size and estimates their relative proportions. All methods produced reproducible differences between human and cow fecal material. Using water samples collected from Tillamook Bay, Oregon, and rivers feeding into it, we found that we could readily detect Bacteroides fecal markers, but Bifidobacterium was much more difficult to detect, making it potentially less useful as an indicator. We are correlating our results with standard fecal coliform measurements, and testing the longevity of the Bacteroides signal. The advantages of this approach are that it avoids the need to cultivate indicator organisms, and it allows quantification of different sources of fecal pollution.
 
Day: Wednesday, Feb. 3
Time: 12:00 - 12:15pm
Location: Sweeney Center
 
Code: SS08WE1200S