We tested the antimicrobial effect of rosemary extracts and the bacteriocin nisin against Campylobacter jejuni at a low storage temperature (8°C) of laboratory and food model conditions (chicken juice and meat) with or without short-term pre-freezing. The antimicrobial effect of rosemary extract was four times greater in laboratory media than in chicken meat juice. However, pre-freezing with plant extract addition proved to have a synergistic antimicrobial by more than 3.0 log reduction of Campylobacter in 48 h in the chicken meat food model.
Genotyping results and epidemiological data confirm the high genetic diversity of C. jejuni isolates in Slovenia, both in isolates from different breeders as well as within individual breeders. Strains isolated from faecal contents and carcass of the same animals had in more than half the cases the same genetic profile, which points to the direct contamination of the carcass on the slaughter line, but suggests also the possibility of cross-contamination of carcasses. Some strains with specific genetic profile, however, dominate, either in a particular geographical area or in individual slaughterhouses.