Assessing microbial differences associated with Campylobacter inoculated poultry rinsates cultured on selective and non-selective plates

The study aimed to assess the relative effectiveness of selective media for isolating Campylobacter species, a foodborne pathogen commonly associated with poultry. Poultry rinsates were inoculated with C. jejuni, C. coli, or C. lari and enriched in 2 × Blood Free Bolton Broth for 20 h at 42 °C under microaerophilic conditions. Enriched samples were spread-plated on Campy-Cefex, mCCDA, and TSA agar and incubated for 48 h under respective conditions. The library was constructed based on the V4 region of the 16S rRNA gene of the subsequent pooled colonies and was sequenced using an Illumina Miseq. The microbial composition was analyzed using 16S rRNA gene sequencing in QIIME2. Results indicated differences in microbial diversity and composition based on species and media. C. jejuni-inoculated rinsates showed the highest evenness and richness, followed by C. coli and C. lari (P < 0.05, Pielou's Evenness, Shannon's Entropy). C. jejuni-inoculated rinsates resulted in a high abundance of non-Campylobacter microbiota, including Lachsnospiraceae and Oscillospiraceae (P < 0.05, ANCOM). Meanwhile, Staphylococcus was significantly more abundant on TSA plates. mCCDA and Campy-Cefex media types did not result in significantly different microbial compositional profiles. The heightened microbial diversity observed in C. jejuni-inoculated rinsates suggests a distinct niche within the poultry environment compared to the other Campylobacter species. More so, microbial diversity and composition in enriched poultry rinsates appear to be influenced by the media used for isolation and the specific Campylobacter species present. The findings highlight the importance of selecting appropriate media for accurately assessing and isolating Campylobacter in poultry-related studies.