Comparison of Pre-Enrichment and Screening Methods for the Detection of Salmonella enterica serovar Agona in Meat Analog Products.

With the growing demand and variety of meat analogs on the commercial market, there is a need to revisit testing methods for foodborne pathogens in these products. The U.S. Food and Drug Administration (FDA) regulatory methods for Salmonella enterica detection in meat analogs follow the Bacteriological Analytical Manual and are relatively time-consuming. Therefore, this study aimed to compare pre-enrichment and screening methods for the detection of Salmonella in meat analogs by evaluating current FDA reference methods alongside alternative pre-enrichment broths and rapid molecular screening techniques. Meat analog samples were inoculated with S. enterica serovar Agona at three levels: (1) uninoculated control, (2) fractional level, and (3) high (+1 log) level. The FDA reference method using lactose broth (LB) with Triton X-100 (LB-T) for pre-enrichment followed by culture confirmation was compared to alternative pre-enrichment methods using LB or buffered peptone water (BPW). Additionally, the current screening method (VIDAS) was compared to rapid screening methods (LAMP and real-time PCR). Pre-enrichment with LB, LB-T, and BPW showed similar proportions of positive test portions following culture confirmation, ranging from 76% for LB-T to 86% for BPW. Similarly, all three screening methods exhibited similar proportions of positive detection outcomes, ranging from 75% for VIDAS to 81% for LAMP. These results suggest that a surfactant was unnecessary for detecting S. enterica Agona applied to meat analog products under the conditions of this study, and that LAMP and real-time PCR are effective screening alternatives to VIDAS. Although one product did not achieve the target fractional response, the data provided meaningful comparative information regarding method performance in meat analog products. Further research is in progress to evaluate additional Salmonella serovars and meat analog products to support the broader applicability of these findings.