Next generation microbiological risk assessment: opportunities of whole genome sequencing (WGS) for foodborne pathogen surveillance, source tracking and risk assessment.

Whole genome sequencing (WGS) of important foodborne pathogens is a technology under development, but is already employed in routine surveillance by public health agencies and is being increasingly exploited in tracing transmission routes and identifying contamination events (source tracking) that take place in the farm-to-fork continuum. Furthermore, data generated from WGS, complemented by other -omics data, have the potential to be integrated into and strengthen microbiological risk assessment. In this paper, we discuss the contribution of WGS in diverse areas important to food safety and public health. Additionally, an outlook of future WGS applications, which should contribute to our understanding of the ecology and physiology of foodborne microorganisms, is presented.

Use of the potential probiotic strain Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers.

Campylobacteriosis is the most frequently reported zoonotic disease in humans in the EU since 2005. As chicken meat is the main source of contamination, reducing the level of Campylobacter in broiler chicken will lower the risk to consumers. The aim of this project was to evaluate the ability of Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers and to investigate the mechanisms that could be involved. Thirty broilers artificially contaminated with C. jejuni were treated by oral gavage with MRS broth or a bacterial suspension (107CFU) of Lb. salivarius SMXD51 (SMXD51) in MRS broth. At 14 and 35days of age, Campylobacter and Lb. salivarius loads were assessed in cecal contents. The impact of the treatment on the avian gut microbiota at day 35 was also evaluated. At day 14, the comparison between the control and treated groups showed a significant reduction (P<0.05) of 0.82 log. After 35days, a significant reduction (P<0.001) of 2.81 log in Campylobacter loads was observed and 73% of chickens treated with the culture exhibited Campylobacter loads below 7log10CFU/g. Taxonomic analysis revealed that SMXD51 treatment induced significant changes (P<0.05) in a limited number of bacterial genera of the avian gut microbiota and partially limited the impact of Campylobacter on Anaerotruncus sp. decrease and Subdoligranulum sp. increase. Thus, SMXD51 exhibits an anti-Campylobacter activity in vivo and can partially prevent the impact of Campylobacter on the avian gut microbiota.

Risk Assessment of Deoxynivalenol by Revisiting Its Bioavailability in Pig and Rat Models to Establish Which Is More Suitable.

Due to its toxic properties, high stability, and prevalence, the presence of deoxynivalenol (DON) in the food chain is a major threat to food safety and therefore a health risk for both humans and animals. In this study, experiments were carried out with sows and female rats to examine the kinetics of DON after intravenous and oral administration at 100 µg/kg of body weight. After intravenous administration of DON in pigs, a two-compartment model with rapid initial distribution (0.030 ± 0.019 h) followed by a slower terminal elimination phase (1.53 ± 0.54 h) was fitted to the concentration profile of DON in pig plasma. In rats, a short elimination half-life (0.46 h) and a clearance of 2.59 L/h/kg were estimated by sparse sampling non-compartmental analysis. Following oral exposure, DON was rapidly absorbed and reached maximal plasma concentrations (Cmax) of 42.07 ± 8.48 and 10.44 ± 5.87 µg/L plasma after (t(max)) 1.44 ± 0.52 and 0.17 h in pigs and rats, respectively. The mean bioavailability of DON was 70.5% ± 25.6% for pigs and 47.3% for rats. In the framework of DON risk assessment, these two animal models could be useful in an exposure scenario in two different ways because of their different bioavailability.