Antimicrobial resistance of bacterial organisms isolated from rats.

OBJECTIVE: To determine if antimicrobial resistance occurs in various bacterial species isolated from rats. METHOD: Two hundred and fifteen rats were trapped from areas in and around Nairobi, Kenya. They were sacrificed and their intestinal, liver and spleen specimens obtained. Various bacterial species were isolated from these specimens. The species were analysed for antimicrobial susceptibility to 12 commonly used antimicrobials using the disc diffusion technique. RESULTS: The bacterial species isolated included pathogenic and potentially pathogenic ones such as Escherichia coli 137, Salmonella typhimurium 1, Klebsiella pneumoniae 2, Enterobacter cloacae 4, Enterobacter sakazakii 2, Citrobacter freundii 3, Morganella morganii (2), Pseudomonas aeruginosa 2 and Burkhoddria cepacia 6. Depending on the species, the resistance to the various antimicrobials were: 0-100% for cefotaxime, nalidixic acid, cefuroxime, tetracycline, chloramphenicol, co-amoxyclav, sulfamethoxazole, ampicillin, trimethoprim and cephradine, 0-66.6% for gentamicin and 0-25% for apramycin. CONCLUSION: The results showed that, rats from the study area harboured bacterial species with antimicrobial resistance. These micro-organisms may form an important reservoir for antibiotic resistance which could pose a public health hazard. Control of rat populations, better management of sewer systems and waste dumping sites are recommended in order to reduce occurrence of these drug resistance reservoirs.