Journal of Emerging Scholarship

Enterococci are the preferred fecal indicator bacteria (FIB) for monitoring the safety of recreational beaches. A reliable and cost-effective method to identify the species of origin for entero cocci-contaminated rivers is essential for decreasing the risk to human health. In this study human and canine fecal samples were analyzed in polymerase chain reaction (PCR) studies with primers reported to amplify targets specific to enterococcal species with the goal of identifying the fecal source. While the primers successfully amplified the target sequences in many samples, amplification in non-target species made identifying one, or a small set of primers, that reliably discriminate between fecal source species more challenging. Alignment and comparison of PCR product sequences were conducted with the goal of designing novel primers with increased specificity. Analysis of multi-locus sequence typing (MLST) data suggested that specific nucleotide variations within loci found in species-specific enterococcal strains might be exploited to determine the source of contamination in local waterways. To this end, primers for two target loci were designed specifically for nucleotide sequences more frequently isolated from canine enterococcal samples and initial screening assays were conducted to optimize conditions and discriminate between source DNA without success. Collection of additional species-specific bacterial samples and additional control type strains are needed to better distinguish between the species of interest in this study.

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