Microbiota in lymph nodes of cattle presented for slaughter in a Canadian meat processing plant

Lymph nodes (LN) harboring pathogenic bacteria, when being incorporated into ground beef, may cause food safety risk. However, there is limited information on the presence of pathogens in LNs in cattle presented for slaughter in Canada. This project investigated the presence of two main foodborne pathogens, Salmonella and Shiga toxin-producing Escherichia coli (STEC) and profiled the microbiota in LNs of cattle in a federally inspected Canadian meat processing plant. We used methods including conventional culture plating, PCR, 16S rRNA gene amplicon sequencing (16S sequencing), and metagenome and whole genome sequencing. LNs at two anatomical locations, subiliac and popliteal, from 80 cattle including both cows (n=34) and steers (n=46), were included in this study.