Thermal inactivation of antimicrobial-resistant Gram-positive cocci in chicken meat: D and Z value determinations

Antimicrobial-resistance in Gram-positive bacteria is reported with increas ing frequency in strains isolated from food animals. Their isolation from c ommercial poultry carcasses and meat products constitute a potential risk t hat resistant strains or resistance genes might spread to humans via the fo od chain. As bacterial inactivation by thermal process is a critical contro l point in the safe preparation of many ready-to-eat foods, it is important to determine the thermal resistance of these organisms. The present study was undertaken to investigate the thermal tolerance (D and Z values) of ant imicrobial-resistant, Gram-positive cocci in ground chicken meat. The antim icrobial-resistant, Gram-positive cocci for this study were isolated from t wo poultry processing plants in Western Australia. D and Z value data indic ate that these isolates do not exhibit enhanced thermal resistant character istics. The estimated lethal effect of the cooking process for chicken meat indicates that an internal temperature of 70 degreesC for 2.1 min would pr ovide a 7-log reduction of all cell suspensions tested.