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Characterization of E. coli strains from rural communities in the Vhembe District (Limpopo South Africa)Banda, Ntshunxeko Thelma 20 September 2019 (has links)
MSc (Microbiology) / Department of Microbiology / Background: Escherichia coli is a facultative anaerobic bacterium that forms part of
the gut microbiota. It is used as an indicator that confirms recent faecal contamination.
E. coli have been identified amongst the pathogens that are mostly responsible for
moderate to severe diarrheal outbreaks in the low and middle-income countries. With
South Africa facing an issue in water scarcity, issues concern poor sanitation and
hygiene practices results in serious public health problems and allows E. coli to be
transmitted from infected human or animal faeces to a new susceptible host using
environmental reservoirs such as soil, water, hands as the transmission pathway.
Objective: The primary objective of the study was to characterize E. coli strains from
rural communities of Vhembe district, Limpopo, South Africa.
Methodology: Households of 7 villages in the Vhembe district were randomly
selected. A total of 81 households (HHs) were part of the study. In each household, a
structured questionnaire was used to background information on WASH practices.
Samples taken from each HH included toilet seat swabs, floor swabs, child and mother
handwash samples, stored water samples and running tap water samples. A total of
399 samples were analysed using Colilert® Quanti-trays®/2000 method to detect the
presence of Escherichia coli. Positive E. coli samples were further identified using
multiplex polymerase chain reaction (m-PCR) to determine the pathogenic strains of
E. coli. Transmission pathways were established using identified strains.
Results: Data from the structured questionnaires showed common problems of
availability of running tap water; lack of provision of sanitation; open practice on
defaecation and very little hand hygiene practices. A total of 91 (22.81%) samples
tested positive for E. coli with the Colilert® Quanti-trays®/2000 method. The mothers’
handwash samples had the most E. coli prevalence followed by stored water samples.
The most prevalent E. coli pathotype was EPEC with the virulence gene eae. Atypical
EPEC (60.44%) outnumbered the typical EPEC (5.49%). The pathotype ETEC was
detected in 41.76% samples and EHEC in 9.89% samples. Transmission pathway was
observed from the different households; with eae gene (aEPEC) being the most
detected from samples looking at the LT gene (ETEC).
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Discussion: All 7 villages are facing common issues such as lacking running water,
poor sanitation and improper hand hygiene practices. The mothers were the most
contaminated and it was observed that its due to the daily activities that they perform
around the house. It is of importance for them to practice proper hand hygiene to
prevent transmission of pathogenic E. coli to the children via direct or indirect
transmission route. The pathogenic E. coli was detected from all different samples
collected from the households including the floor and toilet seat samples. EPEC was
detected the most, and studies have shown that this strain is known to cause diarrheal
infections in young children from developing countries.
Conclusion: The members of the study village households were aware of the WASH
services and its importance. However, proper implementation into their day-to-day life
is lacking due to the high number of TC and E. coli detected from handwash samples
and stored water samples from the households.
Recommendation: Appropriate WASH strategies should be established to ensure
good health at the village households. Further studies should be done to check
possible transmission pathways from more village households. / NRF
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