Geographic Setting Influences Great Lakes Beach Microbiological Water Quality

• Published in: Environmental science & technology 2013-11, Vol.47 (21), p.12054-12063
• Main Authors: Haack, Sheridan K, Fogarty, Lisa R, Stelzer, Erin A, Fuller, Lori M, Brennan, Angela K, Isaacs, Natasha M, Johnson, Heather E
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied sciences; Bacteroides; Bacteroides - genetics; Bacteroides - isolation & purification; Beaches; Biological and medical sciences; Biomarkers - analysis; Campylobacter jejuni; Campylobacter jejuni - genetics; Campylobacter jejuni - isolation & purification; Campylobacter jejuni - pathogenicity; Continental surface waters; E coli; Enterococcus - genetics; Enterococcus - isolation & purification; Environmental science; Escherichia coli - genetics; Escherichia coli - isolation & purification; Exact sciences and technology; Feces - microbiology; Fundamental and applied biological sciences. Psychology; Geography; Great Lakes Region; Humans; Lakes - microbiology; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbial ecology; Microbiology; Natural water pollution; Pathogens; Pollution; Recreation; Ruminantia; Ruminants - microbiology; Salmonella; Salmonella - genetics; Salmonella - isolation & purification; Salmonella - pathogenicity; Shiga-Toxigenic Escherichia coli - genetics; Shiga-Toxigenic Escherichia coli - isolation & purification; Shiga-Toxigenic Escherichia coli - pathogenicity; Staphylococcus aureus; Staphylococcus infections; Various environments (extraatmospheric space, air, water); Water Microbiology; Water Quality; Water treatment and pollution
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es402299a

Understanding of factors that influence Escherichia coli (EC) and enterococci (ENT) concentrations, pathogen occurrence, and microbial sources at Great Lakes beaches comes largely from individual beach studies. Using 12 representative beaches, we tested enrichment cultures from 273 beach water and 22 tributary samples for EC, ENT, and genes indicating the bacterial pathogens Shiga-toxin producing E. coli (STEC), Shigella spp., Salmonella spp, Campylobacter jejuni/coli, and methicillin-resistant Staphylococcus aureus, and 108–145 samples for Bacteroides human, ruminant, and gull source-marker genes. EC/ENT temporal patterns, general Bacteroides concentration, and pathogen types and occurrence were regionally consistent (up to 40 km), but beach catchment variables (drains/creeks, impervious surface, urban land cover) influenced exceedances of EC/ENT standards and detections of Salmonella and STEC. Pathogen detections were more numerous when the EC/ENT Beach Action Value (but not when the Geometric Mean and Statistical Threshold Value) was exceeded. EC, ENT, and pathogens were not necessarily influenced by the same variables. Multiple Bacteroides sources, varying by date, occurred at every beach. Study of multiple beaches in different geographic settings provided new insights on the contrasting influences of regional and local variables, and a broader-scale perspective, on significance of EC/ENT exceedances, bacterial sources, and pathogen occurrence.