Application of an Environmental Phage-Based Assay (Sample6 Detect HT/L) for the Detection of Listeria spp. in Ice Cream

Dairy products are common sources of outbreaks, and early detection of the pathogen is critical to prevent outbreaks of illnesses and financial losses for dairy producers. This study aimed to evaluate Sample6 Detect HT/L for effective detection of and in ice cream. Performance of the Sample6 DETECT HT/L was compared with U.S. Food and Drug Administration (FDA) (BAM) Chapter 10 method for detection of spp. in ice cream using an unpaired study design. R2-enriched samples tested with Sample6 Detect HT/L performed as well as the reference method at all time points tested from 15 to 24 h. R2 is a proprietary blend for use with the test kit that helps with early detection. All the dPOD values (Sample6 Detect HT/L presumptive and confirmed results) equaled zero, indicating 100% concordance between the methods. Both Sample6 Detect HT/L and FDA BAM results showed low dPOD values, with confidence intervals indicating no significant differences between Sample6 Detect HT/L and reference method results. Sample6 Detect HT/L is suitable to detect spp. in ice cream, even with a 12 h enrichment. Sample6 Detect HT/L demonstrated equivalent detection of and from R2-enriched samples as expected with 15 and 18 h enrichment when compared with the 24 h FDA BAM method for These results indicate that Sample6 Detect HT/L, primarily developed for environmental samples, can be used to detect spp. in ice cream with less incubation time, resulting in faster detection.