You are here:
EVALUATION OF HOST SPECIFIC PCR-BASED METHODS FOR THE IDENTIFICATION OF FECAL POLLUTION
Citation:
SANTO-DOMINGO, J., R. LAMENDELLA, J. TANG, O. PANCORBO, O. C. SHANKS, AND C. A. KELTY. EVALUATION OF HOST SPECIFIC PCR-BASED METHODS FOR THE IDENTIFICATION OF FECAL POLLUTION. Presented at American Society for Microbiology Annual Meeting, Atlanta, GA, June 04 - 09, 2005.
Impact/Purpose:
To inform the public
Description:
Microbial Source Tracking (MST) is an approach to determine the origin of fecal pollution impacting a body of water. MST is based on the assumption that, given the appropriate method and indicator, the source of microbial pollution can be identified. One of the key elements of a successful MST method is host-specificity. In this study, we evaluated the host-specificity of human- and ruminant- specific Bacteroides PCR-based methods. Thermal gradients (55°C to 65°C) for the PCR annealing temperatures were tested for each of the assays to determine the optimal amplification condition to discriminate between different hosts. Ruminant-specific assays produced PCR signals with DNA extracted from ruminant fecal samples including cow, sheep, goat, and deer. In contrast, human-specific assays cross-reacted with turkey, chicken, goat, and sheep fecal samples. Sequence analysis of clones generated from PCR products confirmed the isolation of Bacteroides or Bacteroides like 16S rDNA sequences. While the results from this study further validate the Bacteroides-based ruminant assays, our data indicates that the human assays can produce false positive signals. In addition, these results underline the need for further validation of host-specificity in 16S rDNA Bacteroides MST assays prior to their application in field studies.