Purpose: This study aimed to evaluate the hygienic level of a meat processing plant and to identify possible sources of cross contamination. A microbiological detection scheme was performed along with an overall microbial biodiversity study of the samples by 16S metagenetic analysis. Detection of the pathogenic bacteria Clostridium difficile was also performed.
Methods: The production line of two Belgian meat products (pork tomato sauce and white pudding) was monitored. Samples from operator hands (n=8), surfaces (n=9) and products (n=11) were collected at different points of the production. All samples were analysed by classical microbiology to determine the levels of total aerobic viable counts of Enterobacteriaceae, Escherichia coli, Staphylococcus aureus and to detect the presence of C. difficile. Metagenetic analysis was targeted on the V1-V3 hyper-variable region of 16S rDNA. The taxonomical assignment of the populations was performed with Mothur and Blast algorithms.
Results: None of the samples were positive for C. difficile. Using international standards, all of the samples contained acceptable levels of the other bacteria studied. Metagenetic analysis revealed the presence of some taxa in the final products that were not detected in the intermediate products, including populations from the Acinetobacter, Proteus and Staphylococcus genera isolated in some environmental samples. A large proportion of sequences did not belong to known bacterial species.
Significance: Results indicated that C. difficile contamination of the meat products studied was unlikely. High-throughput sequencing reveals a cross contamination in the production line. Further studies are needed to improve taxonomic identification.