We have developed a model, which uses a real-time stable reporting system incorporating our bioluminescent tagged Salmonella enterica serotypes, which can be used to evaluate various pathogenic mitigation strategies. Further, this model may eventually aid in the understanding of how these serotypes are able to survive the processing continuum. We performed this experiment to demonstrate the potential value of this model as a screening tool by evaluating the performance of our bioluminescent Salmonella on chicken skin IWP-2 concentration sections at two temperatures in an aqueous environment. We selected S. Mbandaka and S. Montevideo for this skin attachment experiment
based on the consistent bioluminescence expression we observed within these serotypes (Figure 3). Individual aqueous see more solutions, each containing a Salmonella enterica serotype, were prepared and introduced to chicken skin according to protocol (described below).
Separate plates (24-well) containing replicates of each serotype were placed on a rotating stage at 4°C and 25°C for 2 h. Immediately following this step, bioluminescent imaging was collected after a five minute interval at 37°C for both serotypes and is reported (Figure 4). Bioluminescent monitoring demonstrated the ability to quantify bacteria numbers on chicken skin following cold and warm washes. Our previous work showed washing with 25°C water suppressed the reproduction of Salmonella selleck inhibitor on chicken skin likely through the physical removal of bacteria [19]. Given that Salmonella is a mesophile, refrigeration temperatures further limit bacterial growth and the bacteria become metabolically static. Bioluminescent values, confirming bacteria numbers, at post-wash (4°C) were not shown to be significantly different compared to pre-wash values for both
serotypes (P ≥ 0.25). click here Bioluminescent values at post-wash (25°C) were greater compared to pre-wash values but the difference was not shown to be significantly different (P ≥ 0.125). The increase in bioluminescence following the 25°C wash period is due to increased bacteria growth under favorable metabolic conditions (temperature) and nutrients provided by the chicken skin in solution. With our model we were able to quantify a change in bacteria number by monitoring bioluminescence following treatment. Figure 4 Monitoring bacteria number following 25°C and 4°C water washes. Bioluminescence quantified at 37°C before and after water washes at 4°C and 25°C. A) S. Mbandaka. B) S. Montevideo. These results provide evidence that our model may serve as an accurate and efficient means for in-vitro evaluation of the efficacy of pathogen mitigation strategies, i.e. antimicrobial compounds (AMC) and processing parameters, that may be utilized in the poultry processing industry to control Salmonella enterica.