Microbial quality and antibiotic susceptibility profiles of bacterial isolates from borehole water used by some schools in Ijebu-Ode, Southwestern Nigeria

Abstract

This study was carried out to investigate the microbial quality and antibiotic susceptibility profiles of bacterial isolates from borehole water used by some schools in Ijebu-Ode, Southwestern Nigeria. Borehole water samples were taken from twelve secondary schools over a period of three weeks in September, 2012 and investigated for the presence of indicator organisms such as total coliforms, faecal coliforms, enterococci, heterotrophs and enterobacteriaceae using the spread plate technique. The membrane filtration method was adopted for the isolation pathogenic bacteria. Organisms were further identified using standard methods. Antibiogram of isolates was determined using the Kirby-Bauer method. Total coliform count ranged from 11 (as in sample A) to 2.88 x 102 cfu/100 ml (as in sample F). Total heterotrophic count was least in sample A (49 cfu/100 ml) and too numerous to count (TNTC) in sample C. The incidence of faecal coliform was lowest in sample I (9 cfu/100 ml) and highest in sample H (1.18 x102 cfu/100 ml). Genera of bacteria identified were Staphylococcus aureus, E. coli, Klebsiella sp, Pseudomonas aeruginosa, Enterobacter sp, Salmonella sp. and Serratia sp. Escherichia coli was found to be sensitive to all antibiotics but augmentin. Highest level of resistance was exhibited by Enterobacter sp. It was concluded that the borehole water used by school children in Ijebu-Ode is of poor microbial quality. A possible follow up would be necessary to identify the sources of contamination and disinfection of water in storage tanks before distribution through the school taps is also recommended as a short term solution.