Estimation of the Prevalence of Antimicrobial Resistance in Badgers (Meles meles) and Foxes (Vulpes vulpes) in Northern Ireland.

Antimicrobial resistant (AMR) bacteria can be shared between humans and animals, through food, water, and the environment. Wild animals are not only potential reservoirs of AMR, but are also sentinels mirroring the presence of AMR zoonotic bacteria in the environment. In Northern Ireland, little is known about levels of AMR in bacteria in wildlife, thus the current study aimed to estimate the prevalence of AMR bacteria in wildlife using wildlife species from two ongoing surveys as a proxy. Nasopharyngeal swabs and faecal samples from European badgers (Meles meles) (146 faecal samples; 118 nasal samples) and red foxes (Vulpes vulpes) (321 faecal samples; 279 nasal samples) were collected throughout Northern Ireland and were used to survey for the presence of extended spectrum beta lactamase resistant and AmpC-type beta lactamases Escherichia coli (ESBL/AmpC), Salmonella spp. (only in badgers) and methicillin resistant Staphylococcus aureus (MRSA). ESBLs were detected in 13 out of 146 badger faecal samples (8.90%) and 37 out of 321 of fox faecal samples (11.53%), all of them presenting multi-drug resistance (MDR). Fourteen out of 146 (9.59%) badger faecal samples carried Salmonella spp. [S. Agama (n = 9), S. Newport (n = 4) and S. enterica subsp. arizonae (n = 1)]. Overall, AMR was found only in the S. enterica subsp. arizonae isolate (1/14, 7.14%). No MRSA were detected in nasopharyngeal swabs from badgers (n = 118) and foxes (n = 279). This is the first attempt to explore the prevalence of AMR in the two common wildlife species in Northern Ireland. These findings are important as they can be used as a base line for further research exploring the origin of the found resistance. These results should encourage similar surveys where environmental samples are included to bring better understanding of AMR dynamics, and the impact on wildlife, domestic livestock and humans.

A Bayesian analysis of a Test and Vaccinate or Remove study to control bovine tuberculosis in badgers (Meles meles).

A novel five year Test and Vaccinate or Remove (TVR) wildlife research intervention project in badgers (Meles meles) commenced in 2014 in a 100km2 area of Northern Ireland. It aimed to increase the evidence base around badgers and bovine TB and help create well-informed and evidence-based strategies to address the issue of cattle-to-cattle spread and spread between cattle and badgers. It involved real-time trap-side testing of captured badgers and vaccinating those that tested negative for bTB (BadgerBCG-BCG Danish 1331) and removal of those that tested bTB positive using the Dual-Path Platform VetTB test (DPP) for cervids (Chembio Diagnostic Systems, Medford, NY USA). Four diagnostic tests were utilised within the study interferon gamma release assay (IGRA), culture (clinical samples and post mortem), DPP using both whole blood and DPP using serum. BCG Sofia (SL222) was used in the final two years because of supply issues with BadgerBCG. Objectives for this study were to evaluate the performance of the DPP in field conditions and whether any trend was apparent in infection prevalence over the study period. A Bayesian latent class model of diagnostic test evaluation in the absence of a gold standard was applied to the data. Temporal variation in the sensitivity of DPP and interferon gamma release assay (IGRA) due to the impact of control measures was investigated using logistic regression and individual variability was assessed. Bayesian latent class analysis estimated DPP with serum to have a sensitivity of 0.58 (95% CrI: 0.40-0.76) and specificity of 0.97 (95% CrI: 0.95-0.98). The DPP with whole blood showed a higher sensitivity (0.69 (95% CrI: 0.48-0.88)) but similar specificity (0.98 (95% Crl: 0.96-0.99)). The change from BCG Danish to BCG Sofia significantly impacted on DPP serum test characteristics. In addition, there was weak evidence of increasing sensitivity of IGRA over time and differences in DPP test sensitivity between adults and cubs. An exponential decline model was an appropriate representation of the infection prevalence over the 5 years, with a starting prevalence of 14% (95% CrI: 0.10-0.20), and an annual reduction of 39.1% (95% CrI: 26.5-50.9). The resulting estimate of infection prevalence in year 5 of the study was 1.9% (95% CrI: 0.8-3.8). These results provide field evidence of a statistically significant reduction in badger TB prevalence supporting a TVR approach to badger intervention. They give confidence in the reliability and reproducibility in the DPP Whole Blood as a real time trap-side diagnostic test for badgers, and describe the effect of vaccination and reduced infection prevalence on test characteristics.

Trends in Salmonella serovars and antimicrobial resistance in pigs and poultry in Northern Ireland between 1997 and 2016.

BACKGROUND: In the EU, salmonellosis is the second most commonly reported zoonosis. This pattern is reflected in Northern Ireland. Historically, foodborne salmonellosis has largely been attributed to the consumption of poultry products, and as such a number of legislative measures have been introduced by the EC. These policies focus mainly on five target Salmonella serovars. METHODS: Here the authors present a descriptive analysis of 20 years of data from the Northern Ireland National Reference Laboratory for Salmonella. RESULTS: The study's results show, for poultry submissions, a large decrease in the detection of four of the five targeted Salmonella serovars over the study period, with the fifth serovar undetected throughout the study. Additionally, there was an increase in the detection of a number of other non-regulated serovars. In pigs, S Typhimurium, which is among the most common causes of human salmonellosis, was the most commonly isolated serovar. When comparing levels of antimicrobial resistance in S Typhimurium between livestock groups, the authors found a decrease over time in poultry, but an increase in pigs, highlighting the potential significance of pigs in addressing public health concerns. CONCLUSION: The authors conclude that continued surveillance is important in the assessment of control measures at a national and transnational scale.

Evaluation of the spatial and temporal distribution of and risk factors for Bluetongue serotype 1 epidemics in sheep Extremadura (Spain), 2007-2011.

Extremadura has been one of the regions in Spain most severely affected by Bluetongue (BT) epidemics. The first incursion of BTV, which was successfully eradicated one year later, occurred in 2004, involving the BTV-serotype 4. However, a second incursion occurred in September 2007, this time involving serotype 1. Since then, the implementation of intensive vaccination programs have significantly reduced BTV-1 occurrence, but the disease has not been completely eradicated yet. This study aimed to provide, for the first time, a complete description of the spatial and temporal patterns of BTV-1 occurrence in sheep in Extremadura from 2007 to 2011 and to identify the risk factors that contributed to the seasonal occurrence of BTV-1 in this region. The results showed that risk factors contributing to BTV-1 occurrence in sheep changed between 2007 and 2011. Initially, when the population was still immunologically naïve, the main risk factors for BTV-1 occurrence were extensive management practices, large sheep farms and Culicoides abundance on farms. However, after the implementation of vaccination, other factors became more relevant for BTV-1 occurrence, mostly related to BTV reservoirs, such as the proximity of cattle farms or the introduction of cattle into farms. The Talaverana sheep breed also seemed to be associated with a significantly higher risk of BTV-1 occurrence, although it may be due to confounding factors, such as the geographical concentration of where this breed is kept and/or management practises used for this breed. The results of this study suggest that preventive and control strategies, including vaccination and active surveillance strategies, should be primarily focused on cattle farms kept in close vicinity to sheep flocks as well as in high-risk sheep farms (i.e. farms with a large farm size keeping both cattle and sheep and with a high number of animal introductions). Methods and results presented here may be used to guide decisions for the annual update of the control and eradication program in Spain.