Antimicrobial resistance (AMR) is one of the top public health threats nowadays. Among the most important AMR pathogens, Escherichia coli resistant to extended spectrum cephalosporins (ESC-EC) is a perfect example of the One Health problem due to its global distribution in animal, human, and environmental sources and its resistant phenotype, derived from the carriage of plasmid-borne extended-spectrum and AmpC β-lactamases, which limits the choice of effective antimicrobial therapies. The epidemiology of ESC-EC infection is complex as a result of the multiple possible sources involved in its transmission, and its study would require databases ideally comprising information from animal (livestock, companion, wildlife), human, and environmental sources. Here, we present the steps taken to assemble a database with phenotypic and genetic information on 10,763 ESC-EC isolates retrieved from multiple sources provided by 13 partners located in eight European countries, in the frame of the DiSCoVeR Joint Research project funded by the One Health European Joint Programme (OH-EJP), along with its strengths and limitations. This database represents a first step to help in the assessment of different geographical and temporal trends and transmission dynamics in animals and humans. The work performed highlights aspects that should be considered in future international efforts, such as the one presented here.

This study investigated the ability of Integrated Constructed Wetlands (ICWs) to remove critically important antimicrobial resistant organisms (AROs) from farm wastewater. Influent samples from the untreated farm waste and effluent samples taken at the end of the ICW system were collected monthly from four ICWs, serving four different farm types (suckler, dairy, dairy & poultry and pig). Using selective media to screen for the presence of carbapenemase resistant organisms, plasmid mediated and AmpC β-Lactamase producing organisms (ESBL/pAmpC) and fluoroquinolone resistant organisms, a total of 82 AROs were obtained with the majority being E. coli (n = 79). Statistically significant were the differences on the number of AROs isolated from influent (higher) compared to effluent, as well as a seasonal effect, with less AROs recovered during winter in comparison to other seasons (P < 0.05). On the other hand, there was no significant differences in the recovery of AROs on different farms. The majority of isolates from each of the farms (99%) were multi drug resistant, with 65% resistant to seven or more antimicrobials. A high incidence of tetracycline, trimethoprim/sulfamethoxazole, and ampicillin resistance was common to the isolates from all four farms but there were differences in ESBL levels with 63% of the isolates recovered from Farm 4 (piggery) being ESBLs compared to 18%, 36% and 4.5% recovered from Farms 1 (suckler), 2 (dairy) and 3 (dairy & poultry), respectively. No carbapenemase producing organisms were isolated. Our results showed that ICWs are effective in removing critically important AROs from farm wastewater on all four farm types.

Aims: The aim was to exploit whole genome sequencing (WGS) to assess genomic diversity, identify virulence genes and deduce the proportion of Campylobacter colonized broilers that directly contaminate their carcasses. Methods and Results: Campylobacter jejuni isolates (107) from caeca and carcass neck skin samples (50 pairs from the same batch plus 7 individual caeca) sampled at three poultry slaughterhouses over a one-year period were selected for sequencing (MiSeq; Illumina). FastQ files were submitted to BioNumerics for analysis using the wgMLST scheme for allele calling. Campylobacter cgMLST and hierarchical clustering was performed by applying the single linkage algorithm. Sequence types (STs) were determined in silico from the WGS data and isolates were assigned into clonal complexes (CCs) using the Campylobacter PubMLST.org database. Virulence genes were determined by downloading core sequences from the virulence factor database (VFDB) and the National Center for Biotechnology Information (NCBI). A high degree of diversity was observed with 23 different STs identified. ST257 and CC-21 were the most common STs and CCs, respectively. cgMLST analysis suggested that 56% of carcass contamination was a direct result of contamination from caeca from the same batch. Virulence genes known to play a role in human C. jejuni infection were identified such as the wlaN gene and the genes associated with lipooligosaccharide synthesis, which were identified in 30% of isolates. Conclusions: Caecal colonization was the more plausible occurring source of C. jejuni contamination of broiler carcasses, compared with cross-contamination from another batch or the environment. The high rate of genetic diversity observed amongst caecal isolates is consistent with a wide variety of Campylobacter strains circulating in poultry flocks in Ireland. Significance and Impact of Study: The results will further inform broiler processors and regulators about the influence and importance of on-farm colonization versus slaughterhouse cross-contamination and the relationship between C. jejuni in caeca and carcasses during processing.