To evaluate the performance of a new automated coliform enumeration system (TEMPO® CC) for the quantitative test of coliform bacteria contaminated in domestic livestock processed foods, a total of 507 samples of livestock foods were tested by the TEMPO® CC method, the most probable number (MPN) method, and Petrifilm method, respectively. The results of those three methods were compared to each other. Of 507 samples of livestock processed foods used in this study, 217 samples were contaminated artificially with coliform bacteria and the rest (n=290) were contaminated naturally. The results of the TEMPO® CC method for all samples were equivalent to those obtained from the MPN method, except 8 samples. In addition, 496 (97.8%) out of 507 samples made agreement between the TEMPO® CC method and the Petrifilm method. The correlation coefficients between TEMPO® CC and MPN methods as well as between TEMPO® CC method and Petrifilm method were above 0.9, and the slope and intercept of the linear regression model was different in less than 1 value. In conclusion, there were statistically equivalent levels of performance between the TEMPO® CC and the reference and alternative methods for the enumeration of coliform bacteria in livestock processed foods in this study.

We constructed a standard curve to quantify Listeria monocytogenes in ready-to-eat product, especially sausage samples, using real-time PCR. A standard curve was generated using serially diluted L. monocytogenes cells in distilled water. When cells were artificially inoculated in 10 g of sausage samples in 90㎖ buffered peptone water, the cell concentration of range was approximately 1.0×108 to 100 CFU/㎖. The standard curve of the serially diluted cells was linear for at least seven orders of magnitude from 103 to 109 CFU/㎖ of L. monocytogenes. When cells were diluted in sausages, the linearity range was from 104 to 108 CFU/㎖. The correlation coefficient (R2) of diluted cells was 0.9888 and the slope of the curve was —2.6621. The coefficient and slope of inoculated samples were 0.9916 and —2.747, respectively. The R2 value for serially diluted L. monocytogenes and artificially contaminated sausage samples were acceptable. The approach described in this study represents the potency of the quantification of L. monocytogenes in sausage samples by quantitative real-time PCR. It can be used in monitoring the presence and persistence of this pathogen in sausages.