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Title: Indicators of Microbial Quality in Recreational Waters
Keywords: microbiology, recreational water, indicator, pathogen, qPCR, NGS
Issue Date: 30-Jan-2014
Source: HO DANLIANG (2014-01-30). Indicators of Microbial Quality in Recreational Waters. ScholarBank@NUS Repository.
Abstract: Worldwide, recreational water quality criteria are based on the measurement of fecal indicator bacteria using culture techniques. However various limitations of using traditional fecal indicators in monitoring bathing water quality and predicting disease outbreak exist. In the present study, molecular techniques were evaluated for the ability to detect and predict pathogen occurrence. Optimisation procedures, differentiation of viable and dead bacteria using EMA and PMA pre-treatment, as well as the extent of PCR inhibition occurring within environmental samples were evaluated. The optimised qPCR assays were used to analyse indicator and pathogen count and distribution within six recreational water facilities in Singapore using a point-sampling, spatial and temporal sampling approach. Using correlation analysis, linear regression and FA/PCA, it was discovered that Enterobacteriaceae and M. smithii were good predictors of pathogen presence in study sites subjected to point-sampling, but none of the measured indicators predicted pathogens well when temporal variability was considered. The bacterial indicators and pathogenic markers possessed similar transport characteristics but markedly different decay rates under the same conditions. Direct pathogen detection and discovery was performed using clone library construction and 454-sequencing. Both methods revealed the presence of consistently dominant taxa, but the distribution of pathogenic genera were markedly different across samples, and several genera that were not known to be associated with an aqueous environment were discovered.
Appears in Collections:Master's Theses (Open)

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