An evaluation of U.S. EPA aPCR methods at select Door County, WI beaches

Water quality;Beach closures--Wisconsin--Door County;Wisconsin;Enterococcal infections;Lakes--Recreational use;Enterococcus--Environmental aspects--Door County;Wisconsin.

Campbell, AaronKleinheinz, Greg ;

University of Wisconsin

关键词: Water quality;    Beach closures--Wisconsin--Door County;    Wisconsin;    Enterococcal infections;    Lakes--Recreational use;    Enterococcus--Environmental aspects--Door County;    Wisconsin.;   

Others  :  https://minds.wisconsin.edu/bitstream/handle/1793/76930/CampbellAaron.pdf?sequence=3&isAllowed=y

瑞士|英语

来源: University of Wisconsin

【 摘 要 】

The United States Environmental Protection Agency (EPA) has adoptednumerous techniques for enumerating fecal indicator bacteria, each with varyingadvantages and disadvantages. Traditional culture techniques require 18-24 hours ofincubation and do not provide results in a time sufficient manner to adequately protectpublic health. To help solve this issue, the EPA has developed rapid bacterial indicatormethods based on real-time quantitative polymerase chain reaction (qPCR) technology.Some results from these rapid methods (calibrator cell equivalents, CCE) have shown tocorrelate with results from culture based methods (most probable number, MPN),accurately predicting risk for gastro-intestinal illness. However, there are no comparativestudies that have been done in the Great Lakes or at beaches that are not directlyimpacted by human fecal contributions. In this study, Enterococcus qPCR Method 1609and E. coli qPCR Method C were compared to the defined substrate methods Enterolertand Colilert, respectively, at four beaches in Door County, Wisconsin. Baileys Harborbeach does not exhibit any significant correlations (p>0.05) between the qPCR methodsand defined substrate methods (r2=0.025 (Enterococcus) and 0.002 (E. coli)). Fish Creekbeach shows a positive correlation between Enterococcus qPCR and culture methods (r2=0.387. p<0.01), while method C does not show any significant correlation (r2=0.01,p>0.05). Otumba beach shows weakly positive correlations for both qPCR assays andtheir associated cultures (Enterococcus r2= 0.141 (p=0.0169), E. coli r2=0.363 (p<0.01).Correlations for Sunset beach have r2 values of 0.021 for Enterococcus (p>0.05) and0.104 for E. coli (p=0.0307).In addition to the correlations, the agreement between methods was recorded andcompared to current regulatory standards. If adopted as the regulatory method, qPCRmethods would result in a minimum increase of beach closures of 10 percent and amaximum increase of 47 percent for either method. This suggests that qPCR would bemore protective of public health than current culture based enumeration methods. Theseincreases in beach closures may have potential social and economic ramifications in localcommunities. While it is clear much research is needed to distinguish which method ismore appropriate for the Great Lakes Region and this study suggests a site by siteevaluation of qPCR testing methods before they are adopted for use in monitoringrecreational water quality.