Pages: (23-36 )
Abstract
Drug resistance is a global phenomenon in healthcare institutions. However, drug resistance in medically important bacteria from non-clinical settings is rapidly increasing; thus, raising environmental and public health concerns. Hence, the objective of this study was to determine the prevalence of antibiotic resistance determinants in Gram- negative bacteria from selected animal wastes. Animal waste samples (54) were obtained from 18 farms and subjected to bacteriological assessment. Bacteria were isolated and characterized using API 20E kit. Antibiotics susceptibility of the bacteria was determined by disc diffusion method. Resistance genes and plasmid were profiled by PCR and alkaline lysis, respectively. Of 123 bacteria identified, 19.5, 17.1, 14.6, 14.6, 9.8, 8.9, 8.1 and 7.3% were Enterobacter aerogenes, Serratia, Providencia stuartii, Salmonella enterica, Klebsiella pneumoniae, Escherichia coli, K. oxytoca and Pantoea species, respectively. Susceptibility test indicated that 100, 99, 96, 88, 57, 55 and 50% of the bacteria were resistant to amoxicillin/clavulanate and ceftazidime, gentamicin, cefuroxime, cefixime, ciprofloxacin, nitrofurantoin and ofloxacin, respectively. About 31 and 29% of the bacteria harbored tetA and tetB genes while 15 and 7% harbored sul1 and sul2 genes, respectively. Plasmids with molecular weight of 23.1 kb were found in 16% of the isolates. The study has shown resistant bacteria from animal waste and these bacteria harbor several resistant genes and plasmids. Hence, surveillance system is required to prevent the increasing resistance burden in bacteria within the environment.
Keywords: Antibiotics, API, Integrons, Plasmid, Resistance genes, Wastes,