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Enhanced Salmonella surveillance programmes in poultry were implemented in all European Member States, with minimum prevalence targets for a list of targeted serotypes to safeguard food and public health. Based on the Belgian Salmonella surveillance programme and focusing on poultry, the overarching aim of this study was to highlight possible Salmonella transmissions across the food chain (FC). For this purpose, firstly, the prevalence patterns of Salmonella (targeted and the most prevalent non‐targeted) serotypes along the FC were described over time. Secondly, the effectiveness of the control measures against vertical transmission (breeders to 1‐day‐old broiler and layer chicks) was indirectly assessed by looking into the odds of targeted serotypes detection. Thirdly, it was appraised if Salmonella prevalence can significantly increase during broilers and layers production. In addition, it was tested if being tested negative at the end of production in broilers when tested positive at the entrance is serotype dependent (targeted vs. non‐targeted serotypes). Results showed that, firstly, the prevalence patterns of the listed serotypes were inconstant over time and across the FC. Secondly, the odds of Salmonella targeted serotype detection in 1‐day‐old broiler and in 1‐day‐old layer flocks were lower than in breeder flocks while, thirdly, infection during broiler and layer production can lead to significant increase in positivity in subsequent samples. Finally, being infected by a targeted or by non‐targeted serotype at the entrance of the flock poorly reflects the Salmonella status at the end of production. Note that this study did not make a distinction between the different sources of contamination and the effects of sampling methods and isolation methods should be subject to further investigation. [ABSTRACT FROM AUTHOR]

A number of Listeria monocytogenes strains of different origins are evaluated for invitro invasion capacity for various human cell types and for expression levels of specific virulence genes. The findings reveal that the observation led to study the mRNA expression levels of inlA, inlB, and ami, important virulence genes mediating adhesion and eukaryotic cells, by real-time reverse transcription-PCR for 27 clinical and 37 nonclinical Listeria monocytogenes strains.

Abstract Background Noroviruses (NoVs) are an important cause of acute gastroenteritis in humans worldwide. To gain insight into the epidemiologic patterns of NoV outbreaks and to determine the genetic variation of NoVs strains circulating in Belgium, stool samples originating from patients infected with NoVs in foodborne outbreak investigations were analysed between December 2006 and December 2010. Results NoVs were found responsible of 11.8% of all suspected foodborne outbreaks reported in the last 4 years and the number of NoV outbreaks reported increased along the years representing more than 30% of all foodborne outbreaks in 2010. Genogroup II outbreaks largely predominated and represented more than 90% of all outbreaks. Phylogenetic analyses were performed with 63 NoV-positive samples for the partial polymerase (N = 45) and/or capsid gene (N = 35) sequences. For 12 samples, sequences covering the ORF1-ORF2 junction were obtained. A variety of genotypes was found among genogroups I and II; GII.4 was predominant followed in order of importance by GII.2, GII.7, GII.13, GI.4 and GI.7. In the study period, GII.4 NoVs variants 2006a, 2006b, 2007, 2008 and 2010 were identified. Moreover, phylogenetic analyses identified different recombinant NoV strains that were further characterised as intergenotype (GII.e/GII.4 2007, GII.e/GII.3 and GII.g/GII.1) and intersub-genotype (GII.4 2006b/GII.4 2007 and GII.4 2010/GII.4 2010b) recombinants. Conclusions NoVs circulating in the last 4 years in Belgium showed remarkable genetic diversity either by small-scale mutations or genetic recombination. In this period, GII.4 2006b was successfully displaced by the GII.4 2010 subtype, and previously reported epidemic GII.b recombinants seemed to have been superseded by GII.e recombinants in 2009 and GII.g recombinants in 2010. This study showed that the emergence of novel GII.4 variants together with novel GII recombinants could lead to an explosion in NoV outbreaks, likewise to what was observed in 2008 and 2010. Among recombinants detected in this study, two hitherto unreported strains GII.e/GII.3 and GII.g/GII.1 were characterised. Surveillance will remain important to monitor contemporaneously circulating strains in order to adapt preventive and curative strategies.

The origin of Salmonella contamination on swine carcasses and the distribution of Salmonella serotypes in two commercial slaughterhouses during normal activity are determined by using pulsed-field gel electrophoresis (PFGE) and phage typing. The antibiotic resistance profiles (ARPs) for six antibiotics are determined as well in order to monitor the spread of multidrug-resistant strains in the feces of the pigs, on the carcasses, and in the slaughterhouse environment.

The aim of this study was to better understand the molecular epidemiology of Campylobacter coli isolated from multiple sources in Belgium, by studying the genotypic diversity and antimicrobial resistance phenotypes and resistance mechanisms of 59 C. coli isolates. Isolates from broiler carcasses and human cases were genotyped using multilocus sequence typing (MLST), porA typing, flagellin gene A restriction fragment length polymorphism (flaA–RFLP) typing, and by PCR binary typing (P‐BIT). Thirty‐two MLST sequence types, 24 flaA types, 31 porA alleles, and 29 P‐BIT types were identified among the screened isolates. Some types and alleles were shared among strains recovered from both broiler carcasses and diarrhoeal patients. Both porA typing and MLST revealed a similar discriminatory power (0.969), which was the highest discriminatory power when compared to other methods. Minimum inhibitory concentrations against seven different antibiotics (ciprofloxacin, chloramphenicol, nalidixic acid, streptomycin, tetracycline, gentamicin, and erythromycin) were analysed. Strains were most frequently resistant to tetracycline (81.4%), followed by: ciprofloxacin and nalidixic acid (76.3%); streptomycin (33.9%); erythromycin (27.1%); and chloramphenicol (3.4%). All isolates were sensitive to gentamicin. Multidrug resistance was observed in 24 of 59 C. coli isolates (40.7%). Molecular screening of antimicrobial resistance mechanisms revealed the predominance of the gyrA T86I substitution among ciprofloxacin‐ and nalidixic acid‐resistant isolates, the tet(O) gene among tetracycline‐resistant isolates and the 23S rRNA A2075G mutation among erythromycin‐ resistant isolates. Furthermore, some erythromycin‐resistant isolates harboured a diverse array of resistance mechanisms, including the presence of ermB, 23S rRNA A2074G mutation, and point mutations the rplD and rplV ribosomal genes, and the cmeABC multidrug efflux pump genes. [ABSTRACT FROM AUTHOR]