Save the tradition: control of stec in traditional dairy productions

Among the most serious foodborne diseases are intestinal diseases caused by enteropathogenic and Shiga toxin-producing Escherichia coli (STEC). Outbreaks caused by pathogenic E. coli have been reported as associated with milk and cheese manufactured from raw milk. Therefore, routine surveillance of pathogenic E. coli in milk and cheese processing environment is necessary to verify an early detection of this pathogenic organism to ensure food safety. Apart from the high virulent O157:H7 serotype, other non-O157 serogroups are considered of increasing concern for public health. Most studies were focused on O157:H7 in milk and dairy products, and thus problems associated with non-O157 STEC group may have been underestimated. Another serious concern for public health is the increase in multidrug-resistant E. coli. Currently, the culture-based reference methodologies to detect STEC pathogens are time expensive and intensive.

• Milk, cheese and environmental sample collection for the isolation of E. coli strains and STEC identification.
• Whole-genome sequencing of a select subset of STEC strains in order to characterize virulence-gene profiling and Antimicrobial Resistance (AMR) genes.
• Analysis of lactic acid bacteria population of traditional dairy products previously isolated for the ability to inhibit the STEC growth. 
• Constitution of a putative Lactic acid bacteria (LAB) consortium able to prevent growth of STEC in dairy matrices.
• Testing the robustness and efficiency of the inhibitory microbial consortium against different amounts of STEC inoculum in challenge test with raw milk batches. 
• Microbial analyses will be performed to determine the inhibitory power of the consortium, and 16S rDNA high throughput sequencing of the milk batches and cheeses, will enable us to evaluate the impact of the microbial composition of the raw milk batches on their inhibition properties.

• Determination of the occurrence and characteristics of STEC strains in cow's milk, traditional cheeses manufactured from raw milk in different kind of dairy farm training.
• Estimation of the potential of these sources acting as vehicles of AMR and dairy toxicants.
• Determination of the genetic diversity of isolated E. coli from milk, dairy production, and cattle by means of WGS data and identification of genetic features associated with AMR formation.
• Set up of a new approach for E. coli and in particular STEC detection in dairy matrix and determination of general applicability and limit of detection.
• Validation of a bio preservation strategy against E. coli in traditional raw milk cheeses manufacture.