Survey of the incidence of Aeromonas and Yersinia species in retail foods

Abstract

A total of 520 samples of foods were purchased from six major retailers and tested for the presence of Aeromonas hydrophila (and related species) and Yersinia enterocolitica (and related species). Overall, Aeromonas and Yersinia species were isolated from 10.8% and 4.2%, respectively, of the foods tested. The isolation rate was dependent on the food type and these bacteria were obtained most frequently from fresh (raw) meats (32–57% of samples) and dressed salads (20% of samples). With Yersinia species, the contamination rate for the other food types tested (i.e. fish, fresh salads, sandwiches, milk and dairy products) was 1–5% except for desserts, soft cheeses and bottled water, from which no isolates were made. Foods, other than those above, from which Aeromonas species were commonly isolated (i.e. > 10%) were fish and fresh salads. Isolates of Y. enterocolitica were not considered to be potentially pathogenic as determined using in vitro tests. Several agar plating media and/or enrichment broths were used for both microorganisms. No single isolation procedure was able to recover all the isolates of either genus.