Optimization of Enrichment Protocol for Campylobacter Detection

Abstract

Poultry meat represents the primary source of Campylobacter-associated foodborne illness. The current methods set forth by USDA-FSIS for qualitative detection of Campylobacter from poultry involve selective enrichment to enhance recovery of cells within a sample and can take days to accomplish complete analysis. A great deal of time and expense associated with these methods is accumulated in order to detect Campylobacter, especially for companies testing a high volume of samples. Therefore, there is a demand for more effective and economical methods of analysis that can satisfy challenging criteria. The current research was conducted in order to optimize selective enrichment of Campylobacter and reduce the time and cost associated with detection. The objectives of this study were to optimize selective enrichment of Campylobacter by evaluating growth of Campylobacter jejuni throughout 48 h in various modifications to enrichment media as well as to compare detection of Campylobacter from poultry rinse samples after enrichment in optimized media to the current USDA enrichment method. When growth comparisons in a novel inhibitory broth, Brucella-FBP and blood-free Bolton’s enrichment broth supplemented with Bolton’s selective supplement were made and incubated in a microaerophilic atmosphere, growth of C. jejuni in Brucella-FBP was better (P≤0.05) at 12, 24, and 48 h. Therefore, modified Brucella broth (Brucella-FBP incorporated with cefoperazone and amphotericin B) was developed and optimized for Campylobacter enrichment. Evaluation of modified Brucella broth demonstrated better growth (P≤0.05) of C. jejuni at both 12 h and 48 h than Bolton’s enrichment broth base incorporated with the same inhibitors. Furthermore, enrichment of poultry rinse samples in modified Brucella for 12 h showed better detection (P≤0.05) of natural levels of Campylobacter on carcasses than enrichment in blood-free Bolton’s enrichment broth. Additionally, cost analysis of one liter of prepared medium shows that the expense associated with the media evaluated for selective enrichment of Campylobacter can be greatly reduced without impacting recovery of cells by enriching samples in modified Brucella rather than blood-free Bolton’s broth. The results from this study will provide industry with improved methods for enrichment and detection of Campylobacter while also reducing the cost associated with analysis.