Despite application of HACCP systems at slaughter and during processing, Salmonella contamination is still a significant biological hazard associated with pork products. A better understanding of slaughterhouse risk factors and contamination sources are therefore critical to improve control of this bacterium at slaughter level. The overall objective of this study was to identify the risk factors, at slaughter, associated with the presence of Salmonella in hog carcasses. We were also interested in the genetic characterization of the strains in order to assess the origin of contamination. A questionnaire on various potential risk factors was developed, Over 7400 hogs were tested. These hogs originated from 312 randomly selected production lots. The lots came from 8 different provinces and were tested at time of slaughter in 10 different abattoirs. The tests included serology and bacteriology cultures from mesenteric lymph nodes (MLN) and carcasses. Furthermore, pulsed field gel electrophoresis (PFGE) was conducted to establish genetic profiles of selected isolates from carcasses and MLN to compare their profiles to those recovered from the slaughter environment. Multivariate regression analysis indicated that the cleanliness of the hogs and the status of the scald water were significant factors associated with the final bacteriological status of the carcasses. PFGE analysis showed that most isolates from carcasses were similar to those from animals (MLN) and/or pre-evisceration environment.

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Background: Campylobacter jejuni is responsible for human foodborne enteritis. This bacterium is a remarkable colonizer of the chicken gut, with some strains outcompeting others for colonization. To better understand this phenomenon, the objective of this study was to extensively characterize the phenotypic performance of C. jejuni chicken strains and associate their gut colonizing ability with specific genes.

Tracking sources of contamination is an issue related to food safety. In a preliminary study conducted to evaluate the distribution of thermophilic Campylobacter in the environment surrounding dairy cattle and swine production, a number of Campylobacter lanienae were directly detected by PCR. The amplicons came from dairy cows and pig fecal samples, as well as from stored manure. DNA sequencing of a 360-bp fragment of C. lanienae 16S rRNA gene was performed. Alignment of sequences confirmed the bacterial identification as sequences shared 99-100% homology with C. lanienae 16S rRNA gene sequences available in GenBank. Interestingly, bioinformatics analyses also revealed two different genetic clusters depending on the animal reservoir. More samples and other molecular techniques need to be tested in order to characterize and evaluate the distribution of this microorganism in the agri-food chain.

Campylobacter spp. were recovered from 660 (77.6%) of 850 swine cecal contents at the abattoir and from 24 (8.6%) of 278 specimens from sporadic cases of human diarrhea during the same period in the same geographical area. Campylobacter coli represented 95.7% of Campylobacter isolates recovered from pigs and 8.3% of those isolated from humans. Genetic profiles were determined by pulsed-field gel electrophoresis (PFGE) using KpnI enzyme to characterize the isolates in combination with phenotypic assays to detect production of cytotoxins, enterotoxins, and hemolysins. Among a subset of isolates (n = 10), up to five colonies from the same animal were characterized by PFGE. In 5 (50%) of 10 of the isolates, more than one genetic profile was observed per pig. Among the 100 isolates from pigs selected for further analysis, 81 different genetic profiles were observed, whereas 20 different genetic profiles were found among the 24 isolates of human origin. Cytotoxicity on Chinese hamster ovary cells was observed in 11 (11%) of 98 isolates from pigs and in 5 (21%) of 24 Campylobacter isolates from humans. No enterotoxin production was detected in Campylobacter isolates in this study, but 17 (71%) of 24 human and 61 (63%) of 97 pig isolates showed hemolytic activity. The study of genotypic and phenotypic profiles of swine and human isolates revealed no epidemiological relationship between isolates. The low genomic relatedness observed between groups of isolates and the weak toxicity level of swine isolates suggest that the hazard of contamination of humans by Campylobacter associated with swine production is low.

Dairy cattle are considered a Campylobacter reservoir in the epidemiology of campylobacteriosis. Currently, very little data on the prevalence of Campylobacter in dairy herds are available in the Province of Quebec, Canada. The objectives of this study were to evaluate the prevalence of Campylobacter associated with management practices in 40 dairy cattle herds as well as to characterize the bacterial genetic diversity. Fecal samples from 797 lactating cows of 40 dairy farms, water provided to animals, milk from bulk tank, and fecal matters from pens were analyzed for the presence of Campylobacter. Management information was collected using a short survey and the geographical positioning was mapped for each farm. Bacterial genetic characterization was performed by pulsed-field gel electrophoresis and flaA-typing. In total, 29 farms (72.5%) were found positive for Campylobacter spp. and 20 (50%) of them were positive for Campylobacter jejuni. In animals, 27.6% of the fecal samples were positive for Campylobacter spp. C. hyointestinalis was the most prevalent species (19.3%) in herds, followed by C. jejuni (6.5%). No Campylobacter were recovered from water or milk samples. Component-fed ration systems and the lack of biosecurity measures were associated with an increased prevalence of C. jejuni on the studied farms. Campylobacter-positive farms were scattered throughout the region, and bacterial genetic heterogeneity was observed between farms and inside the herds. This study is the first one to characterize C. jejuni isolates from dairy herds in the Province of Quebec. These observations may be useful in order to elaborate risk-mitigation strategies.

The aim of this work was to investigate the germination process of whole flaxseed and its application in food matrices. Microbial counts, nutrient composition, dough mixing properties and bread-making potential of raw and germinated whole flaxseed were compared. A germination process of 1 day at 20C led to an improvement in the nutrient composition. Fatty acid profiles of whole flaxseed remained unchanged. Antioxidant capacity increased from 210 to 442 μmol Trolox equivalent/g dry matter, lignans from 12.4 to 13.7 mg/g dry matter and free essential amino acids from 115 to 331 μg/100 g dry matter. The flour processed from germinated whole flaxseed had little impact on dough mixing properties and showed good bread-making potential. Increases in the population of lactic acid bacteria (from 2.06 to 5.71 log cfu/g), Enterobacteriaceae (from 3.57 to 5.60 log cfu/g), and yeast and mold (from 2.41 to 5.43 log cfu/g) were observed after the germination process. PRACTICAL APPLICATIONSGermination (or malting) is a well-known process in the barley industry and is mainly dedicated to brewing purposes. In parallel, the germination of grains is recognized to improve their nutritional value while presenting some concerns in terms of microbiological stability. The present work aimed to apply a structured germination process to whole flaxseed in order to produce flours that could be successfully used as an ingredient in food matrix formulation. Our results will help manufacturer and scientist to improve their understanding of the impact of germination process on whole flaxseed nutrient composition and of the importance of controlling microbiological growth. Ultimately, this could lead to the marketing of added-value whole flaxseed ingredients.