Reveal®Salmonella 2.0 Test for Detection of Salmonella spp. in Foods and Environmental Samples

Abstract

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A–E in a variety of food and environmental samples. A Performance Tested MethodSM validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A–E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

Evaluation of rapid screening techniques for detection of Salmonella spp. from produce samples after pre-enrichment according to FDA BAM and a short secondary enrichment

“…Tomatoes did not have any positive detection values by devices at 7 h, and at 24 h only the RV enriched samples were positive by devices. Use of lateral flow devices for detection of Salmonella has shown similar sensitivity with reference methods after secondary enrichment (Hoerner et al 2011;Torlak et al 2012). This study suggests that the lateral flow devices have similar sensitivity as standard plating methods after 24 h. The sensitivity of the devices were variable after a shortened 7-h enrichment in secondary media, but can be of value if a screening result was necessary 1 day sooner.…”