Multidrug resistance of Enterobacter Aerogenes isolated from bovine animals in Okada, Edo state, Nigeria

Abstract

Objectives: This is centered to investigate multidrug resistance among Enterobacter strains seen in bovine animals in Okada Edo state, Nigeria and the need for it to be regularly monitored especially in developing countries as it could be transferred to humans which could result in serious health implications. The emergence of multidrug resistant strains of microorganisms in humans and animals has complicated treatment decisions and may lead to treatment failures. Isolation and identification of Enterobacter aerogenes were made from fifty feacal samples of healthy bovine animal sources between March-July 2011. Method: Evaluation of prevailing resistance was carried out in 22 isolates of E. aerogenes to trimethoprim-sulfamethoxazole, chloramphenicol, sparfloxacin, ciprofloxacin, amoxicillin, imipenem, amoxicillin/clavulanic acid, gentamicin, perfloxacin, ofloxacin, streptomycin, ceftriaxone, ceftazidime, cefotaxime and cefepime. Results: Approximately 91.7% of the isolates were resistant to two or more classes of the antibiotics thereby demonstrating multidrug resistance. Among the multidrug resistant isolates, 13.6% were resistant to streptomycin and gentamicin, 22.7% to chloramphenicol, 27.3% to amoxicillin/clavulanic acid, 31.8% to ofloxacin, 59.1% to cefepime, 68.2% to ciprofloxacin, 77.3% of the multidrug resistant isolates were resistant to trimethoprim-sulfamethoxazole, 72.7% to ceftriaxone, 95.5% to ceftazidime while 100% of the isolates were resistant to cefotaxime. Interestingly, all of the 22 isolates were susceptible to imipenem. All the multidrug resistant isolates had distinct antimicrobial phenotypes. 38.9% multidrug resistant E.aerogenes bovine isolates were found to be extended spectrum beta lactamase (ESBL) producers. The ESBL positive isolates generally showed high level of resistance to all the antibiotics tested. Conclusion: Our results show that the bovine animals may serve as reservoir of extended spectrum beta lactamase producing and multidrug resistant E.aerogenes strains which could be transferred from these bacteria to humans and other animals. There is an urgent need however to recognize all factors involved in the emergence of multidrug resistance, control the use of antibiotics and select best strategies to combat the development of resistance