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Crimean‐Congo hemorrhagic fever virus (CCHFV) causes a serious human tick‐borne disease. In animals, CCHFV infections are mainly subclinical. The circulation of the virus has received little attention in areas where the main vector (Hyalomma spp.) is not considered to be present or established (e.g., the Northern Iberian Peninsula). The presence of antibodies against CCHFV was evaluated in sera collected from 1190 wild boars, 36 red deer, and 36 roe deer in the Basque Country (Northern Iberian Peninsula) in 2014–2019. Antibodies were found in the three wild ungulate species with an overall prevalence of 2.5%. The highest seroprevalence was found in red deer (22.2%) and in the southwest province: Araba (8.6%). The presence of antibodies against CCHFV in wild ungulates reported in this study could be due to an underestimated presence of Hyalomma ticks, the sporadic exposure to infected Hyalomma ticks transported by animals (e.g., migratory birds), or the role of other tick species in the virus's circulation. The detection of exposed animals since 2014 suggests that the circulation of the virus beyond the southwestern regions of the Iberian Peninsula could have been more widespread than previously thought. [ABSTRACT FROM AUTHOR]

Background: Mastitis, inflammation of the mammary gland, is a major disease of dairy cattle and the main cause for antimicrobial use. Although mainly caused by bacterial infections, the aetiological agent often remains unidentified by conventional microbiological culture methods. The aim of this study was to test whether shifts in the bovine mammary gland microbiota can result in initiation or progression of mastitis. Methods: Oxford-Nanopore long-read sequencing was used to generate full-length 16S rRNA gene reads (16S-metabarcoding) to characterise the microbial population of milk from healthy and diseased udder of cows classified into five groups based on their mastitis history and parity. Results: Samples were classified into six enterotypes, each characterised by a marker genus and several differentially-abundant genera. Two enterotypes were exclusively composed of clinical mastitis samples and displayed a marked dysbiosis, with a single pathogenic genus predominating and displacing the endogenous bacterial population. Other mastitis samples (all subclinical and half of the clinical) clustered with those from healthy animals into three enterotypes, probably reflecting intermediate states between health and disease. After an episode of clinical mastitis, clinical recovery and microbiome reconstitution do not always occur in parallel, indicating that the clinical definition of the udder health status does not consistently reflect the microbial profile. Conclusions: These results show that mastitis is a dynamic process in which the udder microbiota constantly changes, highlighting the complexity of defining a unique microbiota profile indicative of mastitis. [ABSTRACT FROM AUTHOR]

Campylobacter fetus is an animal pathogen that contains 2 mammal-associated subspecies: Campylobacter fetus subsp. fetus (Cff) and Campylobacter fetus subsp. venerealis (Cfv) including its biovar intermedius that exhibit different biochemical traits and differences in pathogenicity. Although plasmids are important in the horizontal transfer of antimicrobial resistance genes and virulence factors, C. fetus plasmids are understudied. Here, the closed sequences of 12 plasmids from Spanish C. fetus isolates were compared with the publicly available DNA sequences of C. fetus plasmids and other members of the Campylobacterales order. Sizes of C. fetus plasmids from Spanish isolates ranged between 4 and 50 kb and most of them (10/12) were potentially conjugative. Comparative analysis of the plasmids' gene content revealed a close genetic relationship between the plasmids of C. fetus isolated in Spain and those from other geographical regions, while being clearly distinct from plasmids of other Campylobacter species. Furthermore, C. fetus plasmids were grouped into two main clusters regardless of their geographic location or lineage. The distribution pattern of relaxase, replicase, and single-stranded DNA binding SSB protein encoding genes showed a clustering comparable to that resulting from plasmid whole gene content analysis, suggesting its potential use for the classification of C. fetus plasmids. Most of the larger plasmids harbored mobile genetic elements. These results can help to better understand the evolutionary dynamics and pathogenic implications of C. fetus plasmids. [ABSTRACT FROM AUTHOR]

Background: Bovine genital campylobacteriosis (BGC) is caused by Campylobacter fetus subsp. venerealis (Cfv) including its biovar intermedius (Cfvi). This sexually transmitted disease induces early reproductive failure causing considerable economic losses in the cattle industry. Using a collection of well-characterized isolates (n = 13), C. fetus field isolates (n = 64) and saprophytic isolates resembling Campylobacter (n = 75) obtained from smegma samples of breeding bulls, this study evaluated the concordance of the most used phenotypic (H2S production in cysteine medium and 1% glycine tolerance) and molecular (PCR) methods for the diagnosis of BGC and assessed possible cross-reactions in the molecular diagnostic methods. Results: Characterization at the subspecies level (fetus vs. venerealis) of C. fetus isolated from bull preputial samples using phenotypic and molecular (PCR targeting nahE and ISCfe1) methods showed moderate concordance (κ = 0.462; CI: 0.256–0.669). No cross-reactions were observed with other saprophytic microaerophilic species or with other Campylobacter species that can be present in preputial samples. Whole genome sequencing (WGS) of discrepant isolates showed 100% agreement with PCR identification. For the differentiation of Cfv biovars, comparison of the H2S test (at 72 h and 5 days of incubation) and a PCR targeting the L-cysteine transporter genes showed higher concordance when H2S production was assessed after 5 days (72 h; κ = 0.553, 0.329–0.778 CI vs. 5 days; κ = 0.881, 0.631–1 CI), evidencing the efficacy of a longer incubation time. Conclusions: This study confirmed the limitations of biochemical tests to correctly identify C. fetus subspecies and biovars. However, in the case of biovars, when extended incubation times for the H2S test (5 days) were used, phenotypic identification results were significantly improved, although PCR-based methods produced more accurate results. Perfect agreement of WGS with the PCR results and absence of cross-reactions with non-C. fetus saprophytic bacteria from the smegma demonstrated the usefulness of these methods. Nevertheless, the identification of new C. fetus subspecies-specific genes would help to improve BGC diagnosis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhoea (BVD), one of the most important infectious diseases affecting bovine production systems, is thought to show a subclinical course in most cases, especially in regions that have suffered highBVD prevalence for a long time. However, few studies have assessed this rigorously under non-epidemic conditions. Here we assessed how often active BVD infection in a herd, defined as at least one antigen-positive animal, is associated with clinical signs. Surveying and sampling methods were used to detect BVD infection based on clinical picture. Analysis of 1203 samples of individual animals from 167 herds clinically suspected of BVD infection showed that 33.7% of dairy farms, 30.6% of beef cow-calf farms and 40% of feedlots contained at least one animal positive for BVD viral antigen. Prevalence of BVD infection was 7.7% at the animal level, much higher than the prevalence of 1-3%reported in the literature. This suggests that clinical picture can be useful for detecting activeBVDinfection, and that infections show a variable clinical course. On dairy farms, the presence of at least one antigen-positive animal was associated with a tendency towards lower fertility and higher rates of stillbirths and calf health problems (P< 0.1). On feedlots, such presence was associated with a tendency to a higher of calf health problems. In beef cow-calf systems, however, the presence of an antigen-positive animal was not associated with any particular sign. These results suggest a higher association of active BVD infections spreading in a herd and clinical pictures at the herd level, particularly in dairy herds. [ABSTRACT FROM AUTHOR]

Background: Bluetongue (BT) is a vector-borne disease of ruminants has traditional global distribution in the last decade. Recently, BTV-1 emerged in Southern Spain and caused several outbreaks in livestock reaching the north of the country. The aim of this paper was to review the emergence of BTV-1 in the Basque Country (Northern Spain) during 2007 and 2008 analyzing the possibility that infected Culicoides were introduced into Basque Country by winds from the infected areas of Southern Spain. Methodology/Principal Findings: We use a complex HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model to draw wind roses and backward wind trajectories. The analysis of winds showed September 28 to October 2 as the only period for the introduction of infected midges in the Basque Country. These wind trajectories crossed through the areas affected by serotype 1 on those dates in the South of the Iberian Peninsula. Additionally meteorological data, including wind speed and humidity, and altitude along the trajectories showed suitable conditions for Culicoides survival and dispersion. Conclusions/Significance: An active infection in medium-long distance regions, wind with suitable speed, altitude and trajectory, and appropriate weather can lead to outbreaks of BTV-1 by transport of Culicoides imicola, not only over the sea (as reported previously) but also over the land. This shows that an additional factor has to be taken into account for the control of the disease which is currently essentially based on the assumption that midges will only spread the virus in a series of short hops. Moreover, the epidemiological and serological data cannot rule out the involvement of other Culicoides species in the spread of the infection, especially at a local level. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluated the use of enzyme-linked immunosorbent assay (ELISA) antigen detection for the diagnosis of Border disease virus (BDV) infection in fetuses, stillbirths and newborn lambs. The study notes that it is more suitable to analyze stillbirths and lambs with clinical symptoms by using reverse transcription polymerase chain reaction (RT-PCR) when confirming the presence of BDV. The study concludes that antigen ELISA is less efficient in determining viral presence in stillbirths and lambs.

Background: Listeria monocytogenes is among the most important foodborne bacterial pathogens due to the high mortality rate and severity of the infection. L. monocytogenes is a ubiquitous organism occasionally present in the intestinal tract of various animal species and faecal shedding by asymptomatically infected livestock poses a risk for contamination of farm environments and raw food at the pre-harvest stages. The aim of this study was to determine the prevalence and strain diversity of L. monocytogenes in healthy ruminants and swine herds. Results: Faecal samples from 30 animals per herd were collected from 343 herds (120 sheep, 124 beef cattle, 82 dairy cattle and 17 swine) in the Basque Country and screened in pools by an automated enzyme-linked fluorescent immunoassay (VIDAS®) to estimate the prevalence of positive herds. Positive samples were subcultured onto the selective and differential agar ALOA and biochemically confirmed. L. monocytogenes was isolated from 46.3% of dairy cattle, 30.6% beef cattle and 14.2% sheep herds, but not from swine. Within-herd prevalence investigated by individually analysing 197 sheep and 221 cattle detected 1.5% of faecal shedders in sheep and 21.3% in cattle. Serotyping of 114 isolates identified complex 4b as the most prevalent (84.2%), followed by 1/2a (13.2%), and PFGE analysis of 68 isolates showed a highly diverse L. monocytogenes population in ruminant herds. Conclusion: These results suggested that cattle represent a potentially important reservoir for L. monocytogenes in the Basque Country, and highlighted the complexity of pathogen control at the farm level. [ABSTRACT FROM AUTHOR]