Characterisation of truncation in isolates from farm animals and human cases in the province of Quebec.

The introduction of into the food production chain is a concern, with numerous grouped cases of listeriosis associated with milk-derived or pork-derived products have been documented. Management of this zoonotic pathogen considers all strains as an equal risk. Recently, a new perspective for characterisation of strain virulence was introduced with the discovery of the unaltered sequence of as a determinant of strain virulence; this has also been reported as an infrequent finding among so-called environmental strains, that is, strains isolated from food or from surfaces in food industries. The aim of this study was to differentiate strains isolated from animal cases versus those from human cases and to differentiate clinical strains from environmental ones using a virulence testing model. In Quebec in 2013/2014, the surveillance of clinical isolates registered a total of 20 strains of animal origin and 16 pulsed-field gel electrophoresis types isolated from human cases. The mixed PCR multiplex agglutination protocol used for geno-serotyping clearly discriminated genogroup IVB strains from bovine and human origins. The presence of a premature stop codon single nucleotide polymorphism in the gene sequence in clinical strains and the identical behaviour of particular strains in the model are discussed in this paper from the perspective of industrial management of risk.