Over the past decades, Salmonella 4,[5],12:i:- has rapidly emerged and it is isolated with high frequency in the swine food chain. Although many studies have documented the epidemiological success of this serovar, few investigations have tried to explain this phenomenon from a genetic perspective. Here a comparative whole-genome analysis of 50 epidemiologically unrelated S. 4,[5],12:i:-, isolated in Italy from 2010-2016 was performed, characterizing them in terms of genetic elements potentially conferring resistance, tolerance and persistence characteristics. Phylogenetic analyses indicated interesting distinctions among the investigated isolates. The most striking genetic trait characterizing the analysed isolates is the widespread presence of heavy metals tolerance gene cassettes: most of the strains possess genes expected to confer resistance to copper and silver, whereas about half of the isolates also contain the mercury tolerance gene merA. A functional assay showed that these genes might be useful for preventing the toxic effects of metals, thus supporting the hypothesis that they can contribute to the success of S. 4,[5],12:i:- in farming environments. In addition, the analysis of the distribution of type II toxin-antitoxin families indicated that these elements are abundant in this serovar, suggesting that this is another factor that might favour its successful spread.

Background: Surgical sterilization is the most effective method of contraception for dogs. It also prevents pyometra and reduces the risk of mammary tumour development. However, this procedure also has negative effects, such as urinary incontinence. Steroid hormone deprivation following gonadectomy could also affect canine vaginal mucosa conditions and the microbial community colonizing the vaginal tract. This hypothesis was tested by comparing the vaginal cytology and microbial community of two groups of bitches, including 11 in anoestrus and 10 sterilized bitches (post-pubertal sterilization in the last 4 years). Bacteria were identified through metataxonomic analysis, amplifying the V3-V4 regions of16S rRNAgene, and culturing methods.Results: Vaginal mucosa cytology was suggestive of dystrophic conditions in sterilized bitches, whereas a typical anoestrus pattern with parabasal and intermediate cells was appreciable in anoestrous animals. Metataxonomic analysis revealed large inter-individual variability.Salmonella,MycoplasmaandStaphylococcuswere present in moderate quantities in almost all the samples in both groups. Mollicutes (class level) and Tenericutes (phylum level) were commonly present in moderate quantities in anoestrus samples, whereas these microbes were present at high levels in a single sample from the sterilized group.Based on culturing, a higher number of different species were isolated from the anoestrous bitches, andMycoplasma caniswas exclusively identified in an anoestrous bitch.Staphylococcusspp.was the most frequently isolated genus in both groups, followed byStreptococcusspp., and, among gram-negative bacteria,Escherichiaspp.andHaemophilusspp.A comparison of the numbers of the most frequently isolated genera of bacteria from vaginal cultures of bitches revealed thatPasteurellaandProteuswere the most frequently identified in sterilized animals based on metataxonomic analysis (p-value = 0.0497 and 0.0382, respectively), whereasStreptococcuswas significantly and most frequently isolated from anoestrous bitches using culture methods (pvalue = 0.0436).Conclusions: In this preliminary investigation, no global patterns of the vaginal bacteria community were noted that characterized the condition of the bitches; however, cytology suggested local modifications. Sterilization after puberty caused minimal alterations in the vaginal microbial community of bitches within 4 years after surgery.

Campylobacter is the most frequent foodborne zoonotic bacteria worldwide, with chicken meat being overwhelmingly the most important reservoir for human infections. Control measures implemented at the farm level (i.e., biosecurity or vaccination), which have been successfully applied to limit other pathogens, such as Salmonella, have not been effective in reducing Campylobacter occurrence. Thus, new approaches are needed to fully understand the ecological interactions of Campylobacter with host animals to effectively comprehend its epidemiology. The objective of this study was to analyse longitudinally the gut microbiota composition of Campylobacter-infected and non-infected farms to identify any difference that could potentially be indicative of gut colonization by Campylobacter spp. Differences in the colonization rate and timing were observed at the farms that became positive for Campylobacter jejuni over the investigated time points, even though in positive tests, the occurrence of Campylobacter jejuni gut colonization was not observed before the second week of the life of the birds. Significant differences were observed in the abundances of specific bacterial taxa between the microbiota of individuals belonging to farms that became Campylobacter positive during the study and those who remained negative with particular reference to Bacteroidales and Clostridiales, respectively. Moreover, Campylobacter colonization dramatically influenced the microbiota richness, although to a different extent depending on the infection timing. Finally, a key role of Faecalibacterium and Lactobacillus genera on the Campylobacter microbial network was observed. Understanding the ecology of the Campylobacter interaction with host microbiota during infection could support novel approaches for broiler microbial barrier restoration. Therefore, evidence obtained through this study can be used to identify options to reduce the incidence of infection at a primary production level based on the targeted influence of the intestinal microbiota, thus helping develop new control strategies in order to mitigate the risk of human exposure to Campylobacter by chicken meat consumption.

The ENGAGE project (http://www.engage-europe.eu/) was a collaboration between eight institutions across Europe. The aim was to boost the scientific cooperation to use whole genome sequencing (WGS) analysis in food safety and public health protection. ENGAGE focused on Escherichia coli (commensal E. coli) and different Salmonella spp. serotypes. A total of 3,360 genomes, 778 and 2,582 of E. coli and Salmonella, respectively, were produced. These genomes were stored and shared among partners in a temporary repository to be submitted to the European Nucleotide Archive by the end of the project. Generated genomes were used for benchmarking exercises to assess the possibility of replacing conventional typing with WGS for outbreak investigation. For the analysed strains, the benchmarking exercises showed that SPAdes assembly performed better than Velvet and that, by using different bioinformatics tools, WGS Salmonella serotyping and antimicrobial resistance genes detection, were largely in concordance with phenotypic data. Discrepancies were related to sequence quality and phenotype misclassification rather than to limitations of the bioinformatics tools. All partners were able to infer the expected phylogeny for the Salmonella and Campylobacter isolates in benchmarking exercises. Two WGS proficiency tests (assessing different genomic quality markers) were conducted among partners with satisfactory results. Guidelines including available bioinformatics tools and standard operating procedures (wet and dry lab) were prepared and posted online. Workshops, training courses and twinning programmes were conducted. The training focused on online, Galaxy‐based, and command line bioinformatics tools. To reach out beyond ENGAGE, an e‐learning course (17 videos) was developed and made available online. Several proof of concept projects were run and some outcomes published, e.g. the discovery of colistin resistance gene, mcr‐5. Overall, the project showed that laboratories without previous WGS experience need a period of time to implement and perform WGS for foodborne pathogens routine analysis. All developed material will remain available on the ENGAGE website.