Microbial quality, diversity and antibiotic susceptibility profiles of bacterial isolates from borehole water used by schools in Greater Giyani Municipality, Mopani District, South Africa

Abstract

In the present study, the microbial quality of several boreholes, used by rural schools in Greater Giyani Municipality, was assessed over a six months period to determine their safety for human consumption and to highlight the potential occurrence of water-borne diseases. The microbiological quality of the water sources was performed using the membrane filtration technique, while standard culture methods were used for bacteria isolation. The MicroScan was used for identification and antibiotic susceptibility profiles of isolated potentially pathogenic bacteria. The results obtained indicated that the water quality of the boreholes was poor over the study period (June to October, 2009). Indicator organisms were higher than the acceptable maximum limits prescribed by the South African Department of Water Affairs and Forestry (DWAF) and the World Health Organisation. Numerous organisms that are potential enteric pathogens such as Vibriospp., Shigella species and Klebsiella spp, were isolated throughout the study period. There was high resistance to many antibiotics particularly ampicillin (92%), cefazolin (95.9%), cefuroxime (91.7%) and cefoxitin (92.6%). The most active antibiotics were tobramycin with resistance level of 8.7% and levofloxacin (23.0%). The study indicates that water from the studied boreholes was not suitable for human consumption and may pose a serious threat to the health of consumers and therefore calls for urgent intervention. High level of antibiotic resistance is of concern in the management of infections caused by these organisms. Further studies are needed to identify the sources of contamination in order to curb the negative effect of contaminated water particularly in children. Key words: Antibiotic resistance, bacterial indicators, children, water quality, borehole, schools, South Africa.