Purpose: To determine the antimicrobial susceptibility of Escherichia coli, Salmonella, Campylobacter and Enterococcus in raw retail foods in Australia
Methods: Four retail foods: poultry, beef, pork and lettuce; along with four target organisms: Campylobacter, Salmonella, E. coli and Enterococcus were included in the survey. Nine food-bacteria combinations were chosen where the bacterial target was expected to exceed 10% in prevalence and to allow for the recovery of 100 isolates from each food-bacteria combination. Samples were collected from retail outlets in Sydney, Melbourne, Brisbane and Perth which accounts for the retail supply to 57% of Australians. Resistance to antimicrobials was determined in a central laboratory using Sensititre apparatus and CLSI breakpoints (where available).
Results: Isolation rates of the target organisms were sufficient to achieve the recovery of 100 isolates in seven of the nine food-bacteria combinations. Overall, resistance to the majority of antimicrobials was low by international comparison. Resistance to critically important antibiotics such as vancomycin, fluroquinolones and 3rd and 4th generation cephalosporins was non-existent or extremely low in the 300 Enterococcus, 299 E. coli, 100 Salmonella and 100 Campylobacter isolates tested. Ampicillin resistance in E. coli isolates from pork (28%) was the only resistance shown to be >10% higher than those observed in other international monitoring programs.
Significance: These data suggest that antimicrobial resistance in the selected food-bacteria combinations is generally very low. This data may be useful in managing and controlling AMR development in the Australian food chain and managing resistance in the community.