The Study Of Bacterial Contamination Of Drinking Water Sources: A Case Study Of Mpraeso, Ghana

摘要

The study aimed at determining the presence, type, count and causes of bacterial contamination of water used for drinking and other domestic purposes in Mpraeso. Fifty-four (54) water samples (48 from 8 groundwater wells and 6 from a stream) were collected and analyzed for six months (both during the dry and raining seasons). The results showed that groundwater sources were as polluted as surface water. The detection of bacterial cells in the water sources means that some forms of treatment needed to be done before consumption. The mean count of total coliform and faecal coliform ranged from 299 - 2267 MPN colonies/100 ml water sample and 111 – 1235 MPN colonies/100 ml water sample, respectively. For the groundwater sources, the enterobacteriaceae species detected were Escherichia coli (8 wells), Enterococcus faecalis (8 wells), Klebsiella pneumoniae (6 wells), Enterobacter cloacae (5), Pseudomonas aeruginosa (3), and Proteus mirabilis (3). All these bacterial species were detected in the surface water samples. Introduction Water is considered as the essence of life and access to safe drinking water is a basic human right essential to all. Although water is necessary for the welfare of humankind and for sustainable development, a large proportion of the world’s population do not have access to microbiologically safe sources of water for drinking and other essential purposes (WHO/UNICEF, 2000). Safe drinking water should not represent any significant risk to health over a lifetime of consumption, including different sensitivities that may occur between life stages (WHO, 2006). Sources of drinking water include piped water, rivers, reservoirs, springs, streams, wells, ponds and rain. Studies have shown that the way water is collected, handled after collection and stored at home cause quality deterioration to such an extent that the water poses potential risks of infection to consumers (Pinfold, 1990; Nala et al., 2003; Ampofo and Karikari, 2006).Microbial guidelines seek to ensure that drinking water is free of microorganisms that can cause disease. Microbial hazards are said to represent an overall greater threat than chemical hazards, and in developing countries account for 5.7% of the total global burden of disease (Larmie and Paintsil, 1996). The lack of microbiologically safe drinking water and adequate sanitation measures leads to a number of diseases including cholera, dysentery, salmonellosis, typhoid, and every year millions of lives are lost in developing countries. For the 1.1 billion people who lack access to improved water supplies, and many more with contaminated water, diarrhoeal disease is highly endemic (Clasen et al., 2007). Diarrhoea is a major cause for the death of more than 2 million people per year worldwide, mostly children under the age of five. It is the symptom of infection or the result of a combination of a variety of enteric pathogens (Zamxaka et al., 2004). Improving access to safe drinking water and sanitation are the ways of achieving the objectives of the United Nations Millennium Development Goals (MDGs). The MDGs target for water is to ‘half by 2015 the proportion of people without sustainable access to safe drinking water and basic sanitation’ (WHO/UNICEF, 2004).This study was conducted to enumerate the total and faecal coliforms, determine the presence and types of enterobacteriaceae, and assess the causes of bacterial contamination of drinking water sources in Mpraeso, Ghana. Material and Methods The study area, Mpraeso, is the capital of the Kwahu South District of the Eastern Region of Ghana.Water samples were collected in sterile bottles from each sampling site (8 wells and a stream) between 0500 and 0700 GMT, when the demand for water was high, from January to June 2008. The collection of samples was done as described by Cheesbrough (1984). Samples collected were labelled, placed on ice packs and sent to the Bacteriology Department of Noguchi Memorial Institute for Medical Research (NMI