Work

Optimizing Salmonella Recovery From Commercial Poultry Environmental Samples With Selective Preenrichment

Year: 2025

Type: article

Abstract: • Selective pre-enrichment reduces isolation by 24 h without compromising serovar diversity. • Salmonella quantity is a limiting factor in the use of selective pre-enrichment. • Recovery with selective pre-enrichment and selective enrichment did not differ significantly. The current, culture-based methods for detecting Salmonella are time and resource intensive, as it can take between three to five days with pre-enrichment and selective enrichment steps. Previous work by our group has shortened this process by combining novobiocin and selective ingredients from Rappaport-Vassiliadis (RV) (malachite green; 0.1 g/L) and tetrathionate (TT) (bile salts; 1 g/L) to BPW in parallel, creating an all-encompassing selective pre-enrichment step. In this study, we sought to validate the use of selective pre-enrichment on commercial poultry live production samples, as the increased presence of background bacteria may limit Salmonella recovery. Two pairs of boot sock samples were collected from 35 houses, representing 17 different commercial broiler or breeder farms (n = 70 samples). The samples were cultured under selective pre-enrichment conditions in parallel with standard non-selective pre-enrichment (BPW) followed by selective enrichment (RV, TT). Additionally, molecular enumeration was performed to quantify the amount of Salmonella present in each sample. Overall, Salmonella was found in 74% (52/70) of samples collected, and selective pre-enrichment and selective enrichment conditions each recovered Salmonella in 14/17 farms. The average quantity per sample was greater in those recovered with selective pre-enrichment (5.2 log 10 CFU/sample) than those that were not (3.0 log 10 CFU/sample; p = 0.01, Welch two sample t-test). CRISPR-SeroSeq was used to determine the relative frequency of Salmonella serovars in each sample and culture condition. The proportion of multiserovar populations observed in the selective pre-enrichment conditions (53%, 29/55) was not significantly different from those in selective enrichment conditions (56%, 39/70; p = 0.1, McNemar’s chi-squared test). These findings suggest that increasing the selectivity of the Salmonella pre-enrichment step could eliminate the need for a subsequent selective enrichment, thus reducing the time to Salmonella isolation by 24 hours.

Source: Journal of Food Protection

DOI: 10.1016/j.jfp.2025.100627

Authors: Amy T. Siceloff, Nikki W. Shariat

Institution: University of Georgia

Language: English

Topic: Salmonella and Campylobacter epidemiology

Subfield: Food Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Zero hunger, Good health and well-being

Open Access status: gold

Estimated APC paid: $2,300