High rate of resistance to locally used antibiotics among enteric bacteria from children in Northern Ghana

Objectives: Information on antimicrobial susceptibility of bacterial pathogens is scarce in resource-poor settings. We determined the susceptibility of bacterial enteric pathogens and faecal Escherichia coli isolates obtained from children in urban Tamale, Northern Ghana, to antibiotics widely used in the that area [ampicillin or amoxicillin, trimethoprim/sulfamethoxazole (SXT) and chloramphenicol] and to alternative drugs. Methods: Five Shigella spp., 6 Salmonella spp. and 318 E. coli were isolated from stool specimens obtained from 367 children with or without acute diarrhoea. Isolates were differentiated using standard laboratory procedures and tested using a breakpoint microbroth dilution method for their susceptibility to 18 antimicrobials and by disc diffusion for their susceptibility to chloramphenicol. Results: Although the salmonellae showed an acceptable resistance pattern, E. coli isolates and the closely related shigellae were highly resistant. About 91% and 81% of E. coli isolates from patients or controls, respectively, were resistant to ampicillin (MICs >= 8 mg/L), 88% and 76% to trimethoprim/sulfamethoxazole (MICs >= 80/4 mg/L) and 46% and 41% to chloramphenicol (inhibition zones <= 12 mm). Resistance to beta-lactam antibiotics or chloramphenicol was observed more frequently among isolates obtained from infants when compared with older children (1-4 years of age). Conclusions: Enteric bacteria from children in urban Northern Ghana are highly resistant to antibiotics used in that area. Therefore, new antibiotics should be introduced for the treatment of infections caused by these bacteria. Additionally, the establishment of a surveillance of the prevalence of the main bacterial infectious agents and their antimicrobial resistance is desirable.