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MOLECULAR EVALUATION OF CHANGES IN PLANKTONIC BACTERIAL POPULATIONS RESULTING FROM EQUINE FECAL CONTAMINATION IN A SUB-WATERSHED
Citation:
Simpson*, J M. AND J W. Santo Domingo*. MOLECULAR EVALUATION OF CHANGES IN PLANKTONIC BACTERIAL POPULATIONS RESULTING FROM EQUINE FECAL CONTAMINATION IN A SUB-WATERSHED. WEFTEC 2002 Conference, Chicago, IL, 09/28/-10/02/2002.
Description:
Considerable emphasis has been placed on developing watershed-based strategies with the potential to reduce non-point-source fecal contamination. Molecular methods applied used 16S-ribosomal-deoxyribonucleic-acid (rDNA) to try to determine sources of fecal contamination. Objectives: (1) determine if fecal source microorganisms affected bacterial communities downstream; (2) determine if anaerobic fecal bacteria (Bacteroides) were detectable. Denaturing-gradient-gel-electrophoresis (DGGE) targeting the16S-rDNA V3 region was used to examine microbial community structure. Fecal enterococci increased from (Log10) 1.4 CFU/ml upstream to 8.1 CFU/ml downstream. DGGE profiles were compared using Dices's index (Cs). Upstream DGGE patterns varied more than downstream (Cs = 42% +/- 13). Downstream samples had greater pattern similarity (Cs = 70% +/- 11). Change in pattern similarity suggests that fecal bacteria altered microbial community structure locally and maintained downstream influence. Sequenced DGGE bands were Bacteroides, Prevotella, and uncultured rumen bacteria. Identification of bacteria within watersheds after fecal contamination may allow better selection of microorganism(s) for identifying fecal contamination sources to improve water quality.