Abundance of pathogenic Escherichia coli, Salmonella typhimurium and Vibrio cholerae in Nkonkobe drinking water sources Maggy N. B. Momba, Veronica K. Malakate and Jacques Theron ABSTRACT Maggy N. B. Momba (corresponding author) Department of Water Care, Tshwane University of Technology – Arcadia Campus, 175 Nelson Mandela Drive – Arcadia, Pretoria 0002, South Africa Tel.: +27 82 513 7395 E-mail: mmomba@webmail.co.za Veronica K. Malakate Biochemistry and Microbiology Programme Unit, Faculty of Science and Technology, University of Fort Hare, P/Bag X1314, Alice 5700, South Africa Tel.:+27 40 602 2365 Fax: +27 40 602 2429 E-mail: mmomba@ufh.ac.za Jacques Theron Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa In order to study the prevalence of enteric pathogens capable of causing infection and disease in the rural communities of Nkonkobe, bacterial isolates were collected from several surface water and groundwater sources used by the community for their daily water needs. By making use of selective culture media and the 20E API kit, presumptive Escherichia coli, Salmonella spp. and Vibrio cholerae isolates were obtained and then analysed by polymerase chain reaction assays (PCR). The PCR successfully amplified from water samples a fragment of E. coli uidA gene that codes for b-D-glucuronidase which is a highly specific characteristic of enteropathogenic E. coli, enterotoxigenic E. coli and entero-invasive E. coli. The PCR also amplified the epsM gene from water samples containing toxigenic V. cholerae. Although E. coli was mostly detected in groundwater sources, toxigenic V. cholerae was detected in both surface and groundwater sources. There was a possibility of Salmonella typhimurium in Ngqele and Dyamala borehole water samples. The presence of these pathogenic bacteria in the above drinking water sources may pose a serious health risk to consumers. Key words | ground water, pathogenic bacteria, PCR, rural community, surface water INTRODUCTION In almost all South African metropolitan areas, the consumer is provided with high-quality drinking water. However, in many rural communities, the situation is very different. In 1994, an estimated 14 million people had no access to clean or safe water. Although initiatives were taken and improvement measures implemented, 7 million of the 14 million people in rural areas still lack safe and clean water (Duse et al. 2003). The Nkonkobe district is among those South African rural areas without access to an adequate water supply. The Nkonkobe district is situated in the Eastern Cape Province of South Africa. The population of the Eastern Cape is largely non-urban and poor, with an inadequate water supply infrastructure. The rural communities of this province comprise both scattered villages and subsistence farmers, and formalised towns serving subsistence farmers. The poverty rate in 1998 was 78% and only 25% of households had a tap inside their dwelling (Mey 1998). This implies that many people depend on surface and ground- water sources for their daily water needs. Water from these sources is used directly by communities and the water sources are faecally contaminated and devoid of treatment (Momba & Kaleni 2002; Momba & Notshe 2003). Among the pathogens disseminated in water sources, enteric pathogens are the ones most frequently encoun- tered. Enteric pathogens such as E. coli, V. cholerae and S. typhimurium are usually transmitted to humans by the ingestion of contaminated water and foods. These enteric bacteria are reportedly causative agents of various diseases and their complications (Grabow 1996). The impact of waterborne diseases (such as diarrhoea) is significant in South Africa. Studies have shown that diarrhoea is doi: 10.2166/wh.2006.011 289 Q IWA Publishing 2006 Journal of Water and Health | 04.3 | 2006