Antimicrobial susceptibilities of escherichia coli isolates from food animals and wildlife animals in Sarawak, East Malaysia

A total of 133 E. coli strains isolated from different food animals and wildlife sources in Sarawak, Malaysia were screened to determine their antibiotic-resistance pattern using the disk diffusion methods. The animal sources were broiler and village chickens, cattle, bats and rodents. All E. coli isolates were tested for their resistance patterns towards 12 commonly used antibiotics: ampicillin, carbenicillin, cephalothin, chloramphenicol, gentamicin, nalidixic acid, neomycin, nitrofurantoin, ofloxacin, streptomycin, sulfamethoxazole-trimethoprim and tetracycline. In general, the most frequently encountered form of resistance in all samples was resistance to tetracycline (41.35%) and sulphamethoxazole-trimethoprim (19.55%). Low levels of resistance were for gentamicin, nitrofurantoin and ofloxacin, which demonstrated less than 7% resistance of the total samples being assessed. The Multiple Antibiotic Resistance (MAR) indices were highest for broiler chicken isolates (0.479) and low for bat isolates (0.013). All isolates from both broiler chicken samples were multidrug-resistant E. coli. A high percentage of the isolates from bat (84.62%) and rodent (68.57%) samples were not resistant (totally susceptible) to all the antibiotics tested. The results in this study thus suggest that wildlife do not present a high risk of spreading antibiotic-resistant E. coli to the environment. The higher value of MAR indices as well as prevalence of multiple-resistance patterns of E. coli isolates from food animals demonstrated that indiscriminate use of antibiotics should be discouraged in food animals to overcome future resistance problem. Copyright © 2008 Academic Journals Inc.