Incidence and Antimicrobial Susceptibility of Coliforms in Broiler Products at the North West Province of South Africa

This study was conducted to evaluate the incidence and antibiotic resistance of coliforms in raw and readyto-eat broiler products in the North West Province of South Africa. A total of 120 raw and 60 ready-to-eat samples obtained from butcheries and supermarkets were screened for the presence of coliforms. Coliform species were identified by correlating cultural characteristics on MacConkey and Blood agars and biochemical reactions on Enteropluri-test®/API 20NE. Identified isolates were then tested for antibiotic resistance by disk diffusion method using ampicillin (10 μg), ciprofloxacin (5 μg), amikacin (30 μg), trimethoprim-sulphamethoxasole (25 μg), cefotaxime (30 μg), meropenem (10 μg), gentamicin (10 μg) and erythromycin (15 μg). The results showed that 75% (n = 90/total raw) of raw and 25% (n = 15/total RTE) of RTE products were contaminated with various genera of coliforms. A high frequency of resistance was manifested to ampicillin (93.6%) and erythromycin (97.9%), whereas resistance to other antibiotics tested was moderate to low (27.7% to 6.4%). However, Yersinia pseudotuberculosis (from raw chicken) and Stenotrophomonas maltophilia (from polony) were both resistant to seven out of the eight antibiotics tested. The results indicate that consumption of poultry products can increase consumer exposure to antibiotic resistant organisms. This is the first report on the incidence, in RTE foods in the NWP of South Africa, of Stenotrophomonas maltophilia, a bacterium that easily transfers antibiotic-resistance genes to other bacterial species/genera in the same family.