ANTIBIOTIC SUSCEPTIBILITY OF ESCHERICHIA COLI ISOLATED FROM SOME DRINKING WATER SOURCES IN TAMALE METROPOLIS OF GHANA

Abstract

This is the first report on the antibiotic resistance of Escherichia coli isolated from drinking water samples in Tamale Metropolis of Ghana. Antibiotic susceptibility test was performed using the disc diffusion method and the results interpreted using the Clinical and Laboratory Standards Institute guidelines. A total of 56 water sample Escherichia coli isolates were screened against nine different antibiotics. Overall, 37.90% of the Escherichia coli isolates were resistant, 12.90% were intermediate and 49.21% were susceptible. Resistance to vancomycin (94.64%) and erythromycin (85.71%) was high. Susceptibility to ciprofloxacin (94.64%), gentamicin (91.07%) and ceftrioxine (89.29%) was also high. A relatively higher percentage of the water sample Escherichia coli isolates exhibited intermediate resistance to amoxycillin/clavulanic acid (50%). The Escherichia coli isolates also exhibited 24 antibiotic resistant patterns with the pattern E-VA (erythromycin-vancomycin) and SXT-E-VA-TE (Trimethoprim/sulfamethoxazole-erythromycin-vancomycin-tetracycline) being the commonest (each exhibited by nine different isolates). Multiple antibiotic index (MAR index) ranged from 0.11-0.56. Resistance to five (MAR index of 0.56) and four (MAR index of 0.44) different antibiotics were exhibited by 8 and 21 isolates, respectively. A number of Escherichia coli isolated from different water sources did exhibit the same resistant pattern. This study revealed that Escherichia coli from drinking water sources in Tamale, Metropolis are resistant to some antibiotics. Therefore, the use of antibiotics in animal production and for human treatments in the Metropolis need to be checked and curbed to prevent more isolates from becoming resistant.