Bacterial populations associated with poultry processing in a South African abattoir

Abstract

Bacteria were isolated from yeast extract supplemented tryptone soya agar (TSAYE) plates (357 isolates) and violet red bile glucose agar (VRBGA) plates (311 isolates) of micro- biological surveys in a South African Grade B poultry abattoir. Bacterial populations from TSAYE plates of carcasses (neck skin) were dominated by Acinetobacterspp., Escherichia coli, Micrococcusspp. and Flavobacteriumspp., which collectively comprised 75.4% of isolates, while isolates from VRBGA plates showed dominance of Escherichia coli(80.0%). Environmental isolates dominant on TSAYE plates were Micrococcusspp. from equipment surfaces and air samples of the defeathering area of the abattoir (48.5 and 68.7%, respectively) and Bacillusspp. from air samples of the packaging area (37.4%). Isolates from TSAYE plates of scald tank water were dominated by E. coli(47.8%) and Micrococcusspp. (39.1%), while isolates from immersion chiller water were predominantly E. coli(54.1%). Environmental isolates dominant on VRBGA plates were E. coliin water samples and air of the defeathering and packaging areas (from 93.7 to 100%). E. coli, Enterobacterspp. and Serratiaspp. were dominant on VRBGA plates of equipment surfaces, collectively comprising 77.8% of isolates.