Incidence of Aeromonas and Listeria spp. in red meat and milk samples in Brisbane, Australia.

A total of 150 samples, 50 each of beef, lamb and pork from 10 local retail stores in Brisbane metropolitan area as well as 150 raw bovine bulk milk tank samples obtained from Queensland United Foods (QUF), were examined for the presence of Aeromonas and Listeria spp. over a period of 1 year. Different sets of enrichment and plating media were used to recover the organisms with subsequent identification using conventional biochemical and serotyping techniques. A total of 509 isolates consisting of Aeromonas spp. (350) and Listeria spp. (159) were obtained from 60%, 58%, 74%, 26.6%, 34%, 40%, 30%, 2.6% of samples of beef, Lamb, pork and milk respectively. Motile aeromonads (A. hydrophila, A. sobria, A. caviae) and Listeria innocua were isolated from all kinds of samples whereas L. monocytogenes was only isolated from flesh food. A. hydrophila contributed the largest percentage of the motile aeromonads (60%). The majority of L. monocytogenes cultures were serotype 4.