Explore the vast range of titles available.

Animal tuberculosis (TB) is a multi-host disease caused by members of the Mycobacterium tuberculosis complex (MTC). Due to its impact on economy, sanitary standards of milk and meat industry, public health and conservation, TB control is an actively ongoing research subject. Several wildlife species are involved in the maintenance and transmission of TB, so that new approaches to wildlife TB diagnosis have gained relevance in recent years. Diagnosis is a paramount step for screening, epidemiological investigation, as well as for ensuring the success of control strategies such as vaccination trials. This is the first review that systematically addresses data available for the diagnosis of TB in wildlife following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The article also gives an overview of the factors related to host, environment, sampling, and diagnostic techniques which can affect test performance. After three screenings, 124 articles were considered for systematic review. Literature indicates that post-mortem examination and culture are useful methods for disease surveillance, but immunological diagnostic tests based on cellular and humoral immune response detection are gaining importance in wildlife TB diagnosis. Among them, serological tests are especially useful in wildlife because they are relatively inexpensive and easy to perform, facilitate large-scale surveillance and can be used both ante- and post-mortem. Currently available studies assessed test performance mostly in cervids, European badgers, wild suids and wild bovids. Research to improve diagnostic tests for wildlife TB diagnosis is still needed in order to reach accurate, rapid and cost-effective diagnostic techniques adequate to a broad range of target species and consistent over space and time to allow proper disease monitoring.

Bovine paratuberculosis (PTB) is a chronic granulomatous enteritis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), responsible for important economic losses in the dairy industry. Current diagnostic methods have low sensitivities for detection of latent forms of MAP infection, defined by focal granulomatous lesions and scarce humoral response or MAP presence. In contrast, patent infections correspond to multifocal and diffuse types of enteritis where there is increased antibody production, and substantial mycobacterial load. Our previous RNA-Seq analysis allowed the selection of five candidate biomarkers overexpressed in peripheral blood of MAP infected Holstein cows with focal (ABCA13 and MMP8) and diffuse (FAM84A, SPARC and DES) lesions vs. control animals with no detectable PTB-associated lesions in intestine and regional lymph nodes. The aim of the current study was to assess the PTB diagnostic potential of commercial ELISAs designed for the specific detection of these biomarkers. The ability of these ELISAs to identify animals with latent and/or patent forms of MAP infection was investigated using serum from naturally infected cattle (n = 88) and non-infected control animals (n = 67). ROC analysis revealed that the ABCA13-based ELISA showed the highest diagnostic accuracy for the detection of infected animals with focal lesions (AUC 0.837, sensitivity 79.25% and specificity 88.06%) and with any type of histological lesion (AUC 0.793, sensitivity 69.41% and specificity 86.57%) improving on the diagnostic performance of the popular IDEXX ELISA and other conventional diagnostic methods. SPARC and MMP8 showed the highest diagnostic accuracy for the detection of animals with multifocal (AUC 0.852) and diffuse lesions (AUC 0.831), respectively. In conclusion, our results suggest that quantification of ABCA13, SPARC and MMP8 by ELISA has the potential for implementation as a diagnostic tool to reliably identify MAP infection, greatly improving early detection of MAP latent infections when antibody responses and fecal shedding are undetectable using conventional diagnostic methods.

The current knowledge on the histological structure of the gastrointestinal tract (GIT) in cetaceans is based on general descriptions. The aim of this study was to characterize the histology and expression of immune cell markers in samples from the GIT and lymph nodes (LNs) in a harbour porpoise (Phocoena phocoena) bycaught in the Cantabrian Sea. The thickness of the histological layers of the GIT was measured, being greater in the stomach and anal canal, although no significant differences were found among any intestinal segment (p = 0.448). Variation in thickness, morphology of the folds, and the presence of Peyer’s patches allowed the duodenal ampulla and the distal segments to be distinguished from the rest of the intestine. An immunohistochemical technique was performed to identify the following markers: IBA1 for macrophages, CD3 for T lymphocytes, and CD20 for B lymphocytes. The distribution of immune cells varied significantly along the GIT, with higher percentages of all three cell types in the distal intestine and the anal tonsil. Within the LNs, B lymphocytes represented the predominant cell population. This study provides the first description of the histological structure of the GIT and associated lymphoid tissue in a harbour porpoise, which will be useful for future research studies.

Attaining and maintaining the Official Tuberculosis Free status continues to be a challenge when several domestic and wild hosts contribute to the maintenance of the Mycobacterium tuberculosis complex (MTC). Local tuberculosis hotspots are sometimes identified in cattle in low-prevalence regions. We have, therefore, studied one such hotspot in depth in order to produce an epidemiological diagnosis. Host population size and MTC prevalence were estimated in selected wildlife and in livestock, while on-cattle environmental DNA detection was additionally used as a proxy for risk of exposure at the farm (herd) level. Positive skin test reactors were found on16 of the 24 cattle farms studied in the period 2012-2016. Although all goats tested negative to the skin test during this period, MTC was confirmed in four sheep at slaughter, thus indicating an unknown prevalence of infection in this host species. With regard to wildlife, the prevalence of MTC infection based on culture was 8.8% in the case of wild boar (Sus scrofa), and the only road-killed badger (Meles meles) submitted for culture tested positive. Two criteria were employed to divide the cattle farms into higher or lower risk: tuberculosis testing results and environmental DNA detection. Environmental MTC DNA detection yielded significant differences regarding \"use of regional pastures\" and \"proximity to woodland\". This study suggests that on-animal environmental DNA sampling may help when assessing contact risk as regards MTC in livestock at the herd level. This tool opens up new avenues of epidemiological research in complex multi-host settings.

European badgers ( Meles meles ) are reservoirs for animal tuberculosis (TB) in some European countries, complicating TB control in cattle. Badger vaccination and a deeper understanding of the subsequent protection mechanisms are necessary for effective TB control. In a previous study, two of eight badgers immunized with the heat-inactivated Mycobacterium bovis (HIMB) vaccine exhibited an unusual immune response (divergent), developing exacerbated lesions. The present study aimed to describe the local immune response in divergent badgers (those with severe disease progression), with respect to that observed in standard (where the vaccine showed efficacy) and control badgers. Immunohistochemistry was performed to evaluate immune cells (macrophages, T and B lymphocytes, plasma cells), and proteins (TGF-β, IL-10, Fox-P3) within TB granulomas in the lung and bronchial lymph node (LN), after TB challenge. Lung lesion volume, bacterial load and immunological response were also evaluated. The divergent immune response was characterized by elevated IL-10 and Fox-P3, few macrophages and high B lymphocytes (mainly in lungs), suggesting a Th1/Th2 imbalance with reduced Th1 cellular immunity leading to severe TB. In contrast, vaccinated badgers with a standard immune response showed a balanced response, with significantly lower bacterial loads (85.5% LN and 99.9% lung) than control group. This study provides new insights into the immune mechanisms in HIMB-vaccinated badgers, to improve TB control strategies.

Tuberculosis BCG vaccination induced non-specific protective effects in humans led to postulate the concept of trained immunity (TRAIM) as an innate type of immune mechanism that triggered by a pathogen, protects against others. Killed vaccines have been considered not to be effective. However, field efficacy of a commercial vaccine against paratuberculosis, as well as of a recently developed M. bovis heat-inactivated vaccine (HIMB) prompted to test whether it could also induce TRAIM. To this, we used a sarcoptic mange rabbit model. Twenty-four weaned rabbits were treated orally or subcutaneously with a suspension of either HIMB (10 7 UFC) or placebo. Eighty-four days later the animals were challenged with approximately 5000 S. scabiei mites on the left hind limb. Skin lesion extension was measured every 2 weeks until 92 days post-infection (dpi). Two animals were killed at 77 dpi because of extensive skin damage. The rest were euthanized and necropsied and the lesion area and the mite burden per squared cm were estimated. Specific humoral immune responses to S. scabiei and to M. bovis were investigated with the corresponding specific ELISA tests. Subcutaneously and orally HIMB vaccinated animals compared with placebo showed reduced lesion scores (up to 74% and 62%, respectively) and mite counts (−170% and 39%, respectively). This, together with a significant positive correlation (r = 0.6276, p  = 0.0031) between tuberculosis-specific antibodies and mite count at 92 dpi supported the hypothesis of non-specific effects of killed mycobacterial vaccination. Further research is needed to better understand this mechanism to maximize cross protection.

The growing wild ungulate populations across Europe represents an increasingly important source for the spread of zoonotic pathogens. Blastocystis is a common intestinal protist observed in humans and animals worldwide. Studies on Blastocystis occurrence and subtype (ST) diversity in free-ranging wild ruminants are lacking globally, and more data are needed to understand the epidemiological scenario in wild European ruminants. We collected 833 faecal samples from free-ranging wild ungulates across Spain ( n  = 699) and Portugal ( n  = 134) between 1998 and 2021. Using conventional PCR and next-generation amplicon sequencing, Blastocystis was found in 13.8% (115/833; 95% CI: 11.5–16.3) of the wild ruminants analysed. Its occurrence was significantly higher in Portugal (38.1%, 51/134; 95% CI 29.8–46.8) than in Spain (9.2%, 64/699; 95% CI: 7.1–11.5). Fifteen Blastocystis STs, fourteen previously recognised (ST2, ST5, ST10, ST13, ST14, ST21, ST23–ST26, ST30, and ST42–ST44), and one novel (named ST49), were detected among the surveyed wild ruminant populations. Novel ST49 was described using Oxford Nanopore sequencing to produce full-length reference sequences of the small subunit ribosomal RNA gene. A greater ST diversity was observed in Spanish samples. Mixed infections were found in 58.3% (67/115) of the total Blastocystis -positive samples. Our results have enhanced the knowledge regarding Blastocystis occurrence and ST diversity and host preference present in wild ruminants from the Iberian Peninsula, which will assist in clarifying the relationships between the sylvatic and domestic cycles of this protist and may ultimately provide tools to help manage future public health epidemiological scenarios.

Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears ( Ursus arctos ) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which— Clostridium novyi and verotoxigenic Escherichia coli —not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population.

The ongoing increase in wild boar populations across Europe has fostered human–wildlife conflicts, including the transmission of emerging pathogens with zoonotic importance. Blastocystis is a ubiquitous, faecal-oral transmitted protist that can cause gastrointestinal illnesses and is observed in humans and animals worldwide. The role of wildlife in the epidemiology of Blastocystis is insufficiently understood. Thus, we investigated the occurrence and subtype diversity of Blastocystis in free-ranging wild boars from the Iberian Peninsula using conventional PCR and next-generation amplicon sequencing of a fragment of the ssu RNA gene. A total of 459 wild boar faecal samples were collected across Spain ( n  = 360) and Portugal ( n  = 99) between 2014 and 2021. Blastocystis was present in 15.3% (70/459; 95% CI 12.1–18.9) of the wild boars analysed, and its occurrence was significantly higher in Portugal (34.3%, 34/99; 95% CI 25.1–44.6) than in Spain (10.0%, 36/360; 95% CI 7.1–13.6). Seven Blastocystis subtypes (ST5, ST10b, ST13–ST15, ST24b, and ST43) were detected among the surveyed wild boar populations, with greater variability detected in Portuguese samples. ST5 was identified in all the Blastocystis -positive animals, whereas 14.3% of them harboured ST mixed colonisations. Our results demonstrate that Blastocystis ST5 is particularly adapted to infect wild boars. The additional identification of zoonotic STs reinforces the role of wild boars as spreaders of zoonotic infections with public health significance.