Evaluation of selected diagnostic and intervention strategies for reducing Salmonella contamination of poultry

Abstract

The purpose of the following studies was to evaluate three selected diagnostic and intervention strategies for the potential to improve the microbiological quality of poultry meat with regard to Salmonella contamination. Sampling methodologies were evaluated and compared for sensitivity of Salmonella detection on commercially processed poultry carcasses. Additionally, this same study evaluated potential sites of Salmonella contamination and cross-contamination during specific stages of processing. Another study evaluated the benefit of non-selective pre-enrichment for the detection of low levels of sublethally injured Salmonella enteritidis. The final study investigated the use of a combination of d-limonene and citric acid for the ability to remove Salmonella enteritidis from commercially processed poultry skin. Swab, skin, and carcass rinse samples were obtained from commercially processed poultry carcasses at selected stages within a commercial processing plant. In these studies, culture of excised skin from the ventral aspect of the thoracic inlet was determined to be equal in sensitivity to carcass rinse for the detection of Salmonella. Culture of cotton swabs used to manually swab a similar area in the thoracic inlet region was not effective for detection of Salmonella. These experiments also provided evidence that the site of chill immersion could be a major source for cross-contamination between negative and positive flocks. In order to evaluate the benefit of non-selective pre-enrichment, a standard non-selective pre-enrichment method followed by selective enrichment was compared to a direct selective enrichment method for the ability to detect sublethally injured Salmonella. While a marginal advantage of the non-selective pre-enrichment method was observed, either culture procedure was capable of detecting injured Salmonella at levels incapable of infecting neonatal chicks. In the study designed to evaluate a combined treatment of d-limonene and citric acid for Salmonella decontamination, the combined treatment was effective in causing 8to I 0-fold reductions in recoverable Salmonella from processed poultry thigh skin following 30 s exposure at 26 C. Increasing the temperature from 26 C to 55 C resulted in approximately-'30-fold reductions in recoverable Salmonella. Possible effects on carcass quality and consumer acceptability remain to be determined.