Schmallenberg virus (SBV) was first detected in Germany in November 2011. Confirmation of infection in Ireland was reported on October 30th 2012. The results of a national serological survey carried out in early 2013 suggested that the first introduction of SBV into Ireland probably occurred in the south or southeast of Ireland in the spring or summer of 2012, with subsequent spread eastwards and northwards. It was unclear at that stage whether the virus had survived the winter period and would continue to spread in 2013. The purpose of this study was to monitor the spread of the virus in the mid-west region through the summer and autumn of 2013 using bulk tank milk from selected dairy herds.

Background/Objectives: Bovine mastitis remains a challenge for the Irish dairy industry. This study aimed to explore the seasonality and antimicrobial resistance of mastitis pathogens obtained by the regional laboratories (RVL) of the Department of Agriculture, Food and the Marine. Methods: Seasonality of isolation of the most common bacterial species and antimicrobial resistance of those species repeatedly obtained in the same herds in different years were explored using the RVL diagnostic data. Additionally, whole genome sequencing (WGS) was employed to establish the persistency of Staphylococcus aureus strains within the same herd. Results: A clear seasonality was observed in the isolation of Staphylococcus aureus, Streptococcus uberis, and Escherichia coli from milk. Seasonal differences were statistically significant within and between bacterium. Persistence of resistance within herds was highest in S. aureus against penicillin (35.5% of herds) and in S. uberis against pirlimycin (14% of herds), while E. coli did not show persistence of resistance to any antimicrobials. Sequencing of S. aureus isolates revealed that the strains causing mastitis in ten out of twenty-one herds were similar genetically in different years. In seven of these herds, S. aureus was persistently resistant to penicillin. Isolates from two different herds were practically identical and carried the human immune evasion cluster genes (IEC, scn, sak, chp and sea) suggesting a recent human-bovine host switch event. Conclusions: These findings underscore the importance of implementing targeted biosecurity measures and monitoring programs to mitigate the spread of mastitis-causing pathogens and enhance antimicrobial stewardship in the Irish dairy industry, while it also highlights the significance of including a One Health perspective in surveillance programs.

Background: Escherichia coli, a pathogen commonly infecting humans and bovines, is a prime sentinel indicator and predictor for antimicrobial resistance (AMR). Tracking epidemiological trends of AMR is essential to address this global One Health threat. Aim: To perform a comprehensive retrospective epidemiological analysis of AMR trends in E. coli isolated from human urine and blood and bovine specimens, and compare with antimicrobial consumption or sales data for humans. Methods: All E. coli isolates with susceptibility results from human urine (n = 122,419), blood (n = 2,373) and bovine specimens (n = 585) from 2012–23 in the Mid-West of Ireland were analysed. The resistance trends of nine commonly used antimicrobials were compared with their consumption by humans or sales in community and hospital settings. Results: Over the 12-year period, resistance against common antimicrobials was lowest among the bovine isolates (range: 2–44%). Human urine isolates showed lower resistance (5–59%) than bloodstream isolates (12–69%). There was a downward trend in resistance to all antimicrobials between 2012 and 2023 in the human isolates (p < 0.001), except for piperacillin/tazobactam where resistance increased, in each case correlating with antimicrobial usage. Bovine isolates demonstrated reduced resistance to co-amoxiclav (p = 0.001), with no trend observed for other antimicrobials. Conclusion: Our data showed reduced resistance to many antimicrobials for E. coli from human and bovine populations in our region. Increased use of ‘preferred’ antimicrobials in humans and reduced use of those ‘to be avoided’ was observed. The findings indicate the emerging effectiveness of AMR strategies and highlight the value of One Health AMR.

Culicoides biting midges are ectoparasites that act as vectors of animal and human pathogens. While much research effort has focused on species that serve as vectors for important livestock pathogens (belonging to the then Obsoletus and Pulicaris groups in the Palearctic region), other, less common, species are understudied. This study aimed to shed light on the genetic diversity of this lesser‐studied subgroup. A total of 133 Culicoides midges collected in Onderstepoort light traps in 13 sites across Ireland (June 2022–December 2023) were identified as Culicoides achrayi , Culicoides fascipennis , Culicoides festivipennis , Culicoides kibunensis , Culicoides impunctatus , Culicoides nubeculosus, Culicoides pallidicornis, Culicoides pictipennis , Culicoides poperinghensis , Culicoides salinarius and Culicoides vexans based on their wing morphology. Identities were confirmed using a PCR targeting a 478 bp fragment of the mitochondrial cytochrome C oxidase subunit gene (COI), followed by Sanger sequencing. Resulting sequences were compared against records on GenBank and aligned with international sequences to create phylogenetic trees and networks to assess their genetic diversity and relationship. Overall, 93.5% of morphological identifications were confirmed by COI barcoding. While several haplotypes were only recorded in Ireland, their apparent uniqueness is possibly a reflection of the limited number of published sequences in the database. Overall, there was limited evidence to suggest that midges collected in Ireland are genetically isolated from their continental European counterparts, with many sequences closely resembling or identical to those found elsewhere. The results suggests frequent exchanges between Irish and continental European midge populations, reinforcing the need for continued surveillance. Understanding the genetic structure of less‐well studied Culicoides species provides insights into midge population dynamics and connectivity, and informs future surveillance of midge‐borne pathogens in Ireland.