Antibiograms of Staphylococcus aureus Isolates from Some Ready-To-Eat Products

A total of 229 isolates of Staphylococcus aureus from five ready-to-eat products in Nigeria were tested for their sensitivity to ten commonly used antibiotics. One hundred thirty-eight (60.3%) isolates were resistant to one or more of the antimicrobials but none to all. The resistance of isolates varied from 46.0% in dried fish to 78.1% in roasted beef. The incidence of resistance was 55.3, 58.8 and 69.4% in isolates from fried chicken, dried beef and fried fish, respectively. There was no significant difference in resistance of isolates from various food products (P>0.05, X²). Overall, resistance to penicillin (41.0%), ampicillin (28.4%) and trimethoprim (27.9%) were most frequent, whereas isolates were least resistant to erythromycin (1.3%), neomycin (0.4%) and gentamycin (0.4%). The predominant antimicrobial resistance patterns, irrespective of food source, were penicillin and ampicillin (11.4%), trimethoprim (11.4%) and penicillin (7.9%). Since these staphylococcal isolates were from ready-to-eat products of animal origin exposed to human handling during preparation and sale, their antimicrobial resistance patterns are suggestive of the extent of misuse in medical and veterinary practices in Nigeria.