WRS Masters Defense

Monday, June 6th, 3pm
Elizabeth Hill
WRS Masters Student

Abstract

Thesis Title: 

A High-Throughput Microfluidic qPCR Platform for the Simultaneous Quantification of Fecal Indicator Bacteria, Microbial Source Tracking Markers, and Pathogens in Surface Waters and Municipal Wastewater

 

Abstract:

The contamination of water with enteric pathogens is known to result in adverse human health outcomes. Untreated recreational waters may carry an increased risk of gastrointestinal illnesses for water recreators, especially if waters are contaminated with sewage. Current recreational water quality standards are based on outdated methods that cannot pinpoint fecal sources of pollution or accurately predict the risk of pathogen infection. There is a critical need to elucidate the correlations between fecal pollution sources and pathogens in recreational waters. This study expanded upon previous work to develop a novel Microfluidic qPCR (MFQPCR) platform for the simultaneous detection of microbial source tracking (MST) markers, fecal indicator bacteria (FIB), and pathogens in a single water sample. Eighty previously validated TaqMan probe-based assays were applied for use in 96.96 and 192.24 GE chips from Fluidigm. Results showed that 71 of these assays were capable of quantifying genes within acceptable qPCR quality criteria with uniform concentrations and cycling conditions. Multiple host-specific MST markers, FIB, and pathogens were successfully quantified in wastewater influent and effluent, surface waters, and fecal samples. While virulence factor genes and pathogenic species were infrequently detected, a few significant relationships were observed between pathogens and human MST markers. By these associations, linear regression models were created to estimate the occurrence of Clostridium perfringens, Mycobacteria spp., and E. coli from MST marker quantities and additional physicochemical parameters. Furthermore, the lack of strong observed correlations between qPCR data and MPN quantities for fecal indicators suggested that culture-independent qPCR methodology may be a more accurate and timely tool for the future of water quality monitoring.