Microbial quality of tropical inland waters and effects of rainfall events.

Imagen de Tasha Marie Santiago Rodriguez
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TítuloMicrobial quality of tropical inland waters and effects of rainfall events.
Publication TypeJournal Article
Year of Publication2012
AutoresSantiago-Rodriguez, TM, Tremblay, RL, Toledo-Hernandez, C, Gonzalez-Nieves, JE, Ryu, H, Domingo, JWSanto, Toranzos, GA
JournalAppl Environ Microbiol
Volume78
Issue15
Pagination5160-9
Date Published2012 Aug
ISSN1098-5336
Palabras claveAnalysis of Variance, Animals, Bacteroides, Cattle, Chickens, Coliphages, Enterobacteriaceae, feces, Humans, Lakes, Polymerase Chain Reaction, Puerto Rico, Rain, Rivers, Species Specificity, Tropical Climate, Water Microbiology, Water Pollutants
Abstract

Novel markers of fecal pollution in tropical waters are needed since conventional methods recommended for other geographical regions may not apply. To address this, the prevalence of thermotolerant coliforms, enterococci, coliphages, and enterophages was determined by culture methods across a watershed. Additionally, human-, chicken-, and cattle-specific PCR assays were used to identify potential fecal pollution sources in this watershed. An enterococcus quantitative PCR (qPCR) assay was tested and correlated with culture methods at three sites since water quality guidelines could incorporate this technique as a rapid detection method. Various rainfall events reported before sample collection at three sites were considered in the data analyses. Thermotolerant coliforms, enterococci, coliphages, and enterophages were detected across the watershed. Human-specific Bacteroides bacteria, unlike the cattle- and chicken-specific bacteria, were detected mostly at sites with the corresponding fecal impact. Enterococci were detected by qPCR as well, but positive correlations with the culture method were noted at two sites, suggesting that either technique could be used. However, no positive correlations were noted for an inland lake tested, suggesting that qPCR may not be suitable for all water bodies. Concentrations of thermotolerant coliforms and bacteriophages were consistently lower after rainfall events, pointing to a possible dilution effect. Rainfall positively correlated with enterococci detected by culturing and qPCR, but this was not the case for the inland lake. The toolbox of methods and correlations presented here could be potentially applied to assess the microbial quality of various water types.

DOI10.1128/AEM.07773-11
Alternate JournalAppl. Environ. Microbiol.
PubMed ID22610428
PubMed Central IDPMC3416411
Grant List2R25GM061151-09 / GM / NIGMS NIH HHS / United States