Determining the specificity and sensitivity of previously identified human, gull, ruminant, and poultry genetic markers

Abstract

Fecal contamination of environmental waters is of major concern due to its potential to contaminate shellfish and recreational waters, posing a threat to human health. Microbial source tracking (MS1) is an important methodology for detecting the source of fecal contamination by probing water samples for genetic markers uniquely associated with bacteria from a specific host. The level of performance of genetic markers is measured by testing their specificity and sensitivity which can vary due to geographic and environmental conditions. In this project four genetic markers were tested for their specificity (n=l5, 17, or 18) and sensitivity by analyzing the products of PCR reactions containing DNA from known fecal sources and primers that target each specific marker. It was determined that the human primers, HF183, were 89.5% specific and I00% sensitive. Gull primers, Gul12, were 70.5% specific and 75% sensitive. Lastly, the poultry primers, LA35, were determined to be 100% specific and 50% sensitive. An analysis of ruminant primers, RumBac2, was inconclusive; further processing will be completed.