Comparison of microbial contamination at various sites along the Plankenburg- and Diep Rivers, Western Cape, South Africa

Paulse, A.N.; Jackson, Vanessa Angela; Khan, Wesaal

doi:10.4314/wsa.v35i4.76808

Cited by 20 publications

(16 citation statements)

References 13 publications

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“…Most informal settlements are characterised by the lack of basic sanitation facilities and the inhabitants of such settlements mostly resort to rivers and nearby bushes as their main points of waste disposal. The impact of animal farming [33,34] and informal settlements on the microbial quality of aquatic ecosystems has been previously reported [4,35,36,37,38]. …”

Section: Resultsmentioning

confidence: 99%

Abundance of Pathogenic Escherichia coli Virulence-Associated Genes in Well and Borehole Water Used for Domestic Purposes in a Peri-Urban Community of South Africa

Abia

Schaefer

Ubomba-Jaswa

et al. 2017

IJERPH

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In the absence of pipe-borne water, many people in Africa, especially in rural communities, depend on alternative water sources such as wells, boreholes and rivers for household and personal hygiene. Poor maintenance and nearby pit latrines, however, lead to microbial pollution of these sources. We evaluated the abundance of Escherichia coli and the prevalence of pathogenic E. coli virulence genes in water from wells, boreholes and a river in a South African peri-urban community. Monthly samples were collected between August 2015 and November 2016. In all, 144 water samples were analysed for E. coli using the Colilert 18 system. Virulence genes (eagg, eaeA, stx1, stx2, flichH7, ST, ipaH, ibeA) were investigated using real-time polymerase chain reaction. Mean E. coli counts ranged between 0 and 443.1 Most Probable Number (MPN)/100 mL of water sample. Overall, 99.3% of samples were positive for at least one virulence gene studied, with flicH7 being the most detected gene (81/140; 57.6%) and the stx2 gene the least detected gene (8/140; 5.7%). Both intestinal and extraintestinal pathogenic E. coli genes were detected. The detection of virulence genes in these water sources suggests the presence of potentially pathogenic E. coli strains and is a public health concern.

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Section: Resultsmentioning

confidence: 99%

Abundance of Pathogenic Escherichia coli Virulence-Associated Genes in Well and Borehole Water Used for Domestic Purposes in a Peri-Urban Community of South Africa

Abia

Schaefer

Ubomba-Jaswa

et al. 2017

IJERPH

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“…coli counts (p < 0.05) of up to 3.5 x 10 7 and 1.7 x 10 7 microorganisms/100 ml, respectively, for both river systems were obtained throughout the sampling period in the studies conducted by Paulse et al . [ 16 , 17 ]. Permission was not required from any authority or body to collect water at any of these locations.…”

Section: Methodsmentioning

confidence: 99%

“…The multiple tube fermentation technique as previously modified by Barnes [ 1 ] and employed by Paulse et al . [ 16 , 17 ], was used to enumerate fecal coliforms.…”

Section: Methodsmentioning

confidence: 99%

Co-Detection of Virulent Escherichia coli Genes in Surface Water Sources

et al. 2015

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McNemar’s test and the Pearson Chi-square were used to assess the co-detection and observed frequency, respectively, for potentially virulent E. coli genes in river water. Conventional multiplex Polymerase Chain Reaction (PCR) assays confirmed the presence of the aggR gene (69%), ipaH gene (23%) and the stx gene (15%) carried by Enteroaggregative E. coli (EAEC), Enteroinvasive E. coli (EIEC) and Enterohermorrhagic E. coli (EHEC), respectively, in river water samples collected from the Berg River (Paarl, South Africa). Only the aggR gene was present in 23% of samples collected from the Plankenburg River system (Stellenbosch, South Africa). In a comparative study, real-time multiplex PCR assays confirmed the presence of aggR (EAEC) in 69%, stx (EHEC) in 15%, ipaH (EIEC) in 31% and eae (EPEC) in 8% of the river water samples collected from the Berg River. In the Plankenburg River, aggR (EAEC) was detected in 46% of the samples, while eae (EPEC) was present in 15% of the water samples analyzed using real-time multiplex PCR in the Plankenburg River. Pearson Chi-square showed that there was no statistical difference (p > 0.05) between the conventional and real-time multiplex PCRs for the detection of virulent E. coli genes in water samples. However, the McNemar’s test showed some variation in the co-detection of virulent E. coli genes, for example, there was no statistical difference in the misclassification of the discordant results for stx versus ipaH, which implies that the ipaH gene was frequently detected with the stx gene. This study thus highlights the presence of virulent E. coli genes in river water and while early detection is crucial, quantitative microbial risk analysis has to be performed to identify and estimate the risk to human health.

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“…Various water quality studies have since been conducted in the estuary. Paulse et al (2009) investigated microbial contamination at three sites along the Diep River and found that, at all three sites, the microbial counts exceeded stipulated limits in terms of water quality guidelines. Jackson et al (2009), Hutchings and and Ayeni et al (2010) determined the extent of metal contamination along the lower Diep River.…”

Section: Water Qualitymentioning

confidence: 99%