Stability of biophotonic Eschrechia coli 0157:H7 and its effectiveness as a validation tool in beef purge sampling methodologies
Broadway, Paul Randall
BiophotonicE. coli O157:H7(BEC) was evaluated for growth and stability to evaluate the effectiveness of BEC as a tool to validate pathogen reduction interventions. Escherichia coliO157:H7 containing Xen14 and pAK1 lux plasmids were monitored for growth and stability over 10 d at 2.2˚C and 37˚C. Concentration of BECat 2.2˚C remained constant (P> 0.05) but photonic emissions (RLU/s) changed (P<0.05), resulting in a positive correlation between RLU/s and CFU/mL (P< 0.01; r=0.5718). BEC grown at 37˚C yielded no change after a decrease on day 2 (P>0.05). In phase I, purge was monitored for photonic emission after trim was inoculated with BEC. BECwas found at 4 h in Combo C and D. Phase II purge collection used inoculated trim indicative of trim used currently in the beef industry stored in simulated combos. Neither photonic emission nor CFU’s were enumerated in phase II.