Use of an autobioluminescent Salmonella hadar to monitor the effects of acid and temperature treatments on cell survival and viability on lactic acid-treated poultry carcasses

To determine the long-term effects of a lactic acid rinse on viability and recovery of pathogens, Salmonella Hadar was isolated from poultry and bioluminescent constructs obtained by transformation with the lux (CDABE) gene cassette from Photobacterium phosphoreum. Results indicated that the transformed Salmonella Hadar lux was otherwise phenotypically similar to the wild-type strain. Viability studies were performed by measuring luminescence following lactic acid treatment of turkey breast and subsequent storage at -12, 0, 5, and 10 degrees C. The ability of the S. Hadar lux strain to recover was determined by monitoring light output after incubation at 22 degrees C for 10 h. The results showed that metabolic activity was significantly (P < 0.05) affected by lactic acid and by storage temperatures of - 12, 0, and 5 degrees C. The lowest recovery rate was observed after rinsing with lactic acid and storing at 5 degrees C. The study demonstrated that bacterial bioluminescence is an effective way of monitoring in "real time" the ability of bacteria to recover from stress.