MAMMALIAN DERIVED RUMINOCOCCACEAE POPULATION AS MOLECULAR TARGET OF FECAL CONTAMINATION

Abstract

Domesticated animal's fecal material, as agricultural runoff is a contributor to decreased water quality and subsequent, human exposure to waterborne illness. Fecal contamination of water sources is currently monitored by bacteria indicators such as Escherichia coli (E. coli), enterococci, or fecal coliforms. However, these bacteria typically comprise less than 1% of the intestinal bacterial population, and may not precisely predict the human health risk associated with fecal contamination. The mammalian intestinal tract is dominated by the bacterial phylum Firmicutes and a major population is the family Ruminococcaceae. The main objective of this research was to determine if animal derived Ruminococcaceae can be used as an alternative molecular indicator target for the detection of fecal pollution in surface water. To address this objective a 16S rRNA molecular target for mammalian specific Ruminococcaceae was created using the characterized diversity of rumen gastrointestinal/fecal microbial community. The Ruminococcaceae target was amplified from the fecal DNA samples of dairy cow, pig, goat, camel, bison, and water buffalo. The target population was not amplified from horse, chicken, goose, and human sewage influent DNA samples. In natural water spiked with fresh cow fecal material; the culturable indicator E. coli was detected for four days as compared to one day post inoculation, illustrating rapid signal loss. Following rain events, this population was detected in surface water samples from Spring Brook creek (n=10) and only one sample from Fox River, indicating this creek receives animal fecal pollution. The bacterial community analysis of Spring Brook and Fox River water samples demonstrated an increased diversity in the Spring Brook samples. This is most likely attributed to the surrounding agricultural area, and may suggest a significant input of agricultural related fecal pollution. Overall, this molecular target may prove useful in detecting mammalian fecal contaminations, specially that of agricultural.