Search Results (129)

Background: Zoonotic infection with Mycobacterium bovis continues to occur, particularly in regions lacking bovine tuberculosis surveillance and where the consumption of unpasteurized dairy products, including artisanal cheeses, is common. We describe the clinical and microbiological characteristics, diagnostic procedures, and treatment outcomes of individuals with HIV with M. bovis infection. Methods: We conducted a retrospective study analyzing sociodemographic, clinical, microbiological, and computed tomography (CT) data, as well as treatment outcomes, in 12 patients with HIV with confirmed M. bovis infection. These findings were compared with those of 14 individuals with HIV diagnosed with Mycobacterium tuberculosis infection during the same period. Results: Consumption of unpasteurized dairy products was significantly associated with M. bovis. Patients with M. bovis infection had higher CD4+ T-cell counts compared to those with M. tuberculosis infection (p = 0.01, r = 0.45). All M. bovis cases presented with extrapulmonary disease. CT imaging in M. bovis infection more frequently demonstrated retroperitoneal lymphadenopathy, hepatosplenomegaly, and splenic abscesses compared to M. tuberculosis infection. Microbiological identification was exclusively from extrapulmonary sites in all M. bovis cases. Surgical interventions, including abscess drainage or splenectomy, were significantly more common among M. bovis patients. Conclusions: M. bovis infection in individuals with HIV is characterized by consistent extrapulmonary, often abdominal, involvement. Surgical procedures are frequently required for both diagnosis and management. Targeted efforts to identify M. bovis are warranted, particularly in high-burden regions where unpasteurized dairy consumption remains prevalent. Full article

Mycobacterium bovis is the causative pathogen of bovine tuberculosis (bTB), a disease that affects cattle and other mammals, including humans. Currently, there is no efficient vaccine against bTB, underscoring the need for novel immunization strategies. The M72 fusion protein, composed of three polypeptides derived from Mycobacterium tuberculosis and M. bovis, has demonstrated protective efficacy against M. tuberculosis in clinical trials when combined with the AS01E adjuvant. Given the established efficacy of nanocapsule formulations as vaccine delivery systems, this study evaluated a novel immunization strategy combining BCG with either full-length M72 or a truncated M72 fused to a streptococcal albumin-binding domain (ABDsM72). Both antigens were encapsulated in chitosan/alginate nanocapsules and assessed in a murine M. bovis challenge model. Priming with BCG followed by an M72 boost significantly improved splenic protection compared to BCG alone, but it did not enhance pulmonary protection. Notably, boosting with ABDsM72 further increased the proportion of CD4+KLRG1-CXCR3+ T cells in the lungs of M. bovis-challenged mice, a key correlate of protective immunity. These findings demonstrate that chitosan/alginate-encapsulated antigens enhance BCG-induced immunity, supporting their potential as next-generation vaccine candidates for bTB control. Full article

Background: Bovine tuberculosis (bTB) is an infectious disease which causes significant damage to the farming industry and remains a disease of global significance. Although control strategies have focused on a test and cull approach primarily based around specific cell-mediated immune responses, serological assays are increasingly being used as a supplementary test alongside skin testing and interferon-gamma release (IGRA) assays. The UK is moving towards the use of the Bacillus Calmette–Guérin (BCG) vaccination of cattle as an additional targeted control tool against bTB. However, there are concerns over its potential impact on the outcomes of bTB diagnostic tests and other non-TB assays, such as serological tests for Mycobacterium avium subsp. paratuberculosis (MAP). Methods: We investigated the performance of commercially available serology tests designed to detect bTB and MAP using serum samples from BCG-vaccinated animals which were subsequently infected with Mycobacterium bovis (M. bovis). Results: BCG vaccination per se did not significantly impact the specificity of serological diagnostic tests for bTB or Johne’s disease. However, increased numbers of false-positive responses in bTB serology tests were seen in BCG-vaccinated animals 3 weeks following a tuberculin skin test, where up to 23% and 54% of animals gave a positive result in IDEXX and Enferplex tests, respectively. Furthermore, M. bovis infection gave rise to false-positive test results for Johne’s disease, irrespective of the animals’ prior BCG vaccination status. Conclusions: Caution should be taken when assessing results from serology tests for bTB if tuberculin skin testing has occurred shortly before collection of blood from BCG-vaccinated cattle. Furthermore, these results highlight the potential for misdiagnosis of MAP infection when using serology tests in bTB-infected cattle. Full article

Mycobacterium is one of the most dangerous pathogens of both animals and humans. Bovine tuberculosis (BTB) is a disease caused by mycobacteria belonging to the Mycobacterium tuberculosis complex (MTBC), which spreads mainly among domestic cattle but also to mammals other than cattle. The transmission of MTBC between different species requires research and epidemiological investigations to control its spread. When multiple species are a reservoir of infection, it poses a significant public health and veterinary concern. In this study, the diagnosis of alpaca, cattle, horses, dogs, a sheep and a cat from one farm suspected of bovine tuberculosis was performed. The animals (except for one horse, the dogs and the cat) were euthanised after the intradermal tuberculin tests. Mycobacterial isolation from animal tissue samples was performed. The obtained Mycobacterium strains were genotyped using spoligotyping and mycobacterial interspersed repetitive unit–variable number tandem repeat (MIRU-VNTR) methods. The isolates from a horse, two cows, a sheep and an alpaca were classified as Mycobacterium (M.) bovis. The single M. bovis spoligotype SB0666 pattern was isolated, and the MIRU-VNTR results presented the same 222632237401435 patterns. The molecular investigation uncovered information on the relationship of Mycobacterium bovis. Full article

Gene-edited cattle overexpressing natural resistance-associated macrophage 1 (NRAMP1) have demonstrated enhanced resistance to tuberculosis (TB). However, introducing synthetic sequences and selection markers may pose potential risks. The endogenous editing of target gene promoters could effectively mitigate these risks. To date, no available mutation sites in the bovine NRAMP1 promoter have been identified to enhance host resistance to TB. In this study, we identified a unique mutation editing site, designated as 2SP, within the bovine NRAMP1 promoter, using bioinformatics analysis and dual luciferase assays. The mutation at the 2SP site specifically increased NRAMP1 promoter activity by 2.3-fold after Mycobacterium tuberculosis H37Ra infection, without modifying promoter activity in non-infected groups. By using base editing techniques, an endogenously edited THP-1 cell line with a mutation at the homologous region of the 2SP site was generated, without introducing screening markers. In H37Ra infection experiments, the edited THP-1 cells specifically upregulated NRAMP1 expression and significantly inhibited H37Ra proliferation, while maintaining baseline NRAMP1 expression levels in the absence of infection. In this research, we identified a novel mutation site and provided a fundamental reference for the development of gene-edited cattle with enhanced resistance to TB. Full article

Bovine tuberculosis (bTB) is a zoonotic infectious disease and a chronic wasting illness. Accordingly, detecting and eradicating bTB remains a significant challenge in South Korea. This study evaluated the efficacy of a modified enzyme-linked immunosorbent assay (ELISA) protocol for detecting bTB in cattle. The protocol included two ELISA tests: one performed on the day of purified protein derivative (PPD) inoculation and another seven days post-inoculation. Results show a significant increase in ELISA detection rates, from 11% to 76%, particularly in cattle that tested positive for the tuberculin skin test (TST) and/or interferon-gamma (IFN-γ) assays (p < 0.0001). Notably, some cattle that were negative or had doubtful results in TST and IFN-γ assays transitioned to ELISA positive post-PPD inoculation. Additionally, some cattle identified as positive only by ELISA (S/p value ≥ 0.3) were confirmed to have bTB through gross examination or real-time reverse transcription polymerase chain reaction (rRT-PCR). The proposed protocol was validated in bTB outbreak farms using S/p thresholds of 0.3 (PPD inoculation day) and 0.5 (seven days post-PPD), enabling the detection of infected cattle missed by TST and IFN-γ assays. Implementing this approach successfully eradicated bTB in outbreak farms with minimal culling. These findings highlight the potential of incorporating sequential ELISA tests to enhance bTB detection and support eradication efforts. Full article

This cross-sectional study investigated knowledge, attitudes, and practices (KAP) regarding bovine tuberculosis surveillance and analyzed factors influencing KAP among Thai slaughterhouse personnel, utilizing a One Health approach. A validated questionnaire was administered to 208 participants across five geographical regions of Thailand. Statistical analysis revealed moderate mean scores for knowledge (5.28/10), attitudes (38.55/65), and practices (34.62/50). Significant differences were observed in knowledge scores across education levels (F = 3.427, p = 0.005) and job positions (F = 4.562, p = 0.011), with higher education and managerial positions being associated with better performance. Path analysis demonstrated positive correlations among KAP components (p < 0.05), with the strongest correlation between attitudes and practices (r = 0.543). The most significant risk factors for poor practices were identified as lack of training (OR = 2.76, 95% CI: 1.45–5.24, p = 0.002) and inadequate tuberculosis screening (OR = 2.31, 95% CI: 1.18–4.52, p = 0.015). The Knowledge–Practice gap index of −31.14 indicated substantial discrepancy between knowledge and implementation. Developing targeted training programs is needed by focusing on knowledge enhancement and awareness-building, as well as fostering inter-agency collaboration in line with the One Health approach enhance the efficiency of bovine tuberculosis surveillance in Thailand. Full article

Tuberculosis is a zoonotic chronic respiratory infectious disease caused by the Mycobacterium tuberculosis complex. The outbreak and epidemic of tuberculosis can seriously threaten human and veterinary health. To investigate the effects of environmental factors on tuberculosis in domestic ruminants, we collected data regarding the prevalence of tuberculosis in cattle, buffaloes, sheep, and goats in China (1956–2024) from publicly published literature and available databases. We identified the key risk factors among six major air pollutants and 19 bioclimatic variables; simulated the risk distribution of tuberculosis in cattle, buffaloes, sheep, and goats in China using the maximum entropy ecological niche model; and evaluated the effects of environmental factors. The area under the curve of the model was 0.873 (95% confidence interval, 0.851–0.895). The risk factors that most significantly influenced the prevalence of tuberculosis were the nitrogen dioxide (NO₂) level, mean temperature of the coldest quarter, cattle distribution density, sheep distribution density, ozone (O₃) level, and precipitation of the driest month. The predicted map of tuberculosis risk in cattle, buffaloes, sheep, and goats indicated that the high-risk regions were mainly distributed in South, North, East, and Northwest China. Improved surveillance is needed in these high-risk areas, and early preventive measures must be implemented based on the risk factors identified to reduce the future prevalence of tuberculosis in cattle, buffaloes, sheep, and goats. Full article

Tuberculosis (TB), primarily caused by Mycobacterium tuberculosis (M. tb) and Mycobacterium bovis (M. bovis), remains the leading cause of death from a single infectious agent globally. Intracellular survival is crucial for their virulence; yet, the underlying mechanisms are not fully understood. This study aimed to demonstrate the significance of a previously unannotated bovine gene ENSBTAG00000011305 in M. bovis intracellular survival. This gene was termed NMRAL2_Bovine due to its inclusion of the NmrA domain which has a relation to nitric oxide (NO) production. We used CRISPR/Cas9 to knock out NMRAL2_Bovine in bovine lung epithelial cells and observed a significant decrease in M. bovis-induced cell death and the intracellular bacterial count, alongside increased NO levels. A transcriptome analysis revealed the upregulation of pathways linked to NO, IL-6, and TNF-α production, which was confirmed by the increased expression of iNOS, IL-6, and TNF-α. Correspondingly, Western blotting indicated that key signaling pathways, including NF-κB and MAPK, were activated. In conclusion, our findings determined that NMRAL2_Bovine functions as a negative regulator of the inflammatory response induced by M. bovis infection at the cellular level and, thereby, provide a novel insight into TB pathogenesis and a potential target for developing novel host-directed therapies against TB. Full article

Bovine tuberculosis (bTB) is a zoonotic disease with consequences for public health as well as the economy. In the EU, compulsory eradication programmes have been applied, and most territories in Italy have been reported as disease-free (FTs). However, outbreaks (OBs), i.e., an officially confirmed occurrence of bTB in one or more animals in an establishment, have continued to be reported. In this study we provide an overview of bTB in terms of OB numbers in cattle from Italian FTs. Legislative sources were collected to find the FTs, the relevant declaration of free status year (FSY), and regional control and surveillance plans. Then, descriptive and statistical analyses were applied to the collected OBs. A total of 12 regions and 19 provinces were declared FTs in the 20 years from 2003 to 2023. Differences in regional plans were observed with respect to the percentages of herds that were annually controlled (control frequency). Overall, 370 OBs were recorded. A non-statistically significant decrease in the OB incidence rate after the FSY was declared. However, a notable increase in OBs detected at slaughterhouses after the FSY suggests that control systems (serological tests) at the herd level are not completely effective. Differences in the herds’ control frequencies among FTs seem to not have had a significant influence on the observed OB number. The Tuscany region was the most affected FT based on the OB numbers after the FSY (especially in the last year). Epidemiologically relevant primary determinants seem to be the farming system (semi-extensive and adjacent herds) and the cattle movements from positive incidence areas (trade and animal fairs). The role of wild boars in the disease maintenance cannot be excluded. The results of this study stress the need to revise bTB eradication and surveillance plans based on risk analysis. Full article

Background/Objectives: Developing interventions for Johne’s disease, which focuses on controlling Mycobacterium avium subsp. paratuberculosis (MAP) in contaminated environments by treating infected cows and preventing transmission from diseased animals, is a critical priority. Bacteriophage (phage) therapy, an emerging biological intervention, offers a promising alternative for the treatment and management of MAP infections. Methods: In this study, we generated an MAP-specific lytic phage library aimed at characterizing the therapeutic potential of phages under environmental and biological conditions that mimic those encountered in infected cattle such as ruminal fluid, milk, colostrum, and the bovine intestinal epithelium, a key site of MAP colonization and, later, transmission. Results: Our library contains a diverse collection of phages that have demonstrated robust lytic activity against MAP. The host range of these phages was thoroughly assessed, revealing that several isolates produce clear plaques on a range of MAP strains, as well as other pathogenic non-tuberculous mycobacterial (NTM) species and M. tuberculosis strains. This broad host range expands the therapeutic potential of the phage collection, positioning it as a potential cross-species antimicrobial tool. In vitro tests under conditions replicating the rumen, milk, and colostrum environments show that selected phages maintain stability and lytic efficacy, even in the presence of complex biological fluids. Furthermore, a subset of these phages was capable of preventing MAP colonization and invasion in cultured bovine epithelial cells, suggesting their potential for direct prophylactic application in cattle. Conclusions. Our collection of MAP phages represents a valuable source that can be developed into probiotic-like preparations, offering a cost-effective solution for prophylaxis and control of Johne’s disease. Full article

Background/Objectives: Vaccines may improve the control and eradication of bovine tuberculosis. However, the evaluation of experimental candidates requires the assessment of the protection, excretion, transmission and biosafety. A natural transmission trial among likely infected animals was conducted. Methods: Seventy-four male heifers were randomly distributed (five groups) and vaccinated subcutaneously with attenuated strains (M. bovis Δmce2 or M. bovis Δmce2-phoP), a recombinant M. bovis BCG Pasteur (BCGr) or M. bovis BCG Pasteur. Then, they cohoused with a naturally infected bTB cohort under field conditions exposed to the infection. Results: A 23% of transmission of wild-type strains was confirmed (non-vaccinated group). Strikingly, first vaccination did not induce immune response (caudal fold test and IFN-gamma release assay). However, after 74 days of exposure to bTB, animals were re-vaccinated. Although their sensitization increased throughout the trial, the vaccines did not confer significant protection, when compared to the non-vaccinated group, as demonstrated by pathology progression of lesions and confirmatory tools. Besides, the likelihood of acquiring the infection was similar in all groups compared to the non-vaccinated group (p > 0.076). Respiratory and digestive excretion of viable vaccine candidates was undetectable. To note, the group vaccinated with M. bovis Δmce2-phoP exhibited the highest proportion of animals without macroscopic lesions, compared to the one vaccinated with BCG, although this was not statistically supported. Conclusions: This highlights that further evaluation of these vaccines would not guarantee better protection. The limitations detected during the trial are discussed regarding the transmission rate of M. bovis wild-type, the imperfect test for studying sensitization, the need for a DIVA diagnosis and management conditions of the trials performed under routine husbandry conditions. Re-vaccination of likely infected bovines did not highlight a conclusive result, even suggesting a detrimental effect on those vaccinated with M. bovis BCG. Full article

The development of vaccines and effective diagnostic methods for bovine tuberculosis requires an understanding of the immune response against its causative agent, Mycobacterium bovis. Although this disease is primarily investigated and diagnosed through the assessment of cell-mediated immunity, the role of B cells and antibodies in bovine tuberculosis has been relatively undervalued and understudied. Current evidence indicates that circulating M. bovis-specific antibodies are not effective in controlling the disease. However, local humoral immune responses may contribute to either defence or pathology. Recent studies in animal models and cattle vaccine trials suggest a potential beneficial role of B cells in tuberculosis control. This review discusses the role of B cells and antibodies in bovine tuberculosis and explores antibody-based diagnostics for the disease, including traditional techniques, such as different ELISA, new platforms based on multiple antigens and point-of-care technologies. The high specificity and sensitivity values achieved by numerous antibody-based tests support their use as complementary tests for the diagnosis of bovine tuberculosis, especially for identifying infected animals that may be missed by the official tests. Full article

Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a chronic disease with economic impact on ruminant farming worldwide. The Canary Islands count with the fourth largest goat population in Spain and are “officially free” of bovine tuberculosis. Twelve farms were included with 2774 serum samples tested by an enzyme-linked immunosorbent assay (ELISA) for detection of anti-MAP antibodies in two sessions. In the first session, an overall apparent prevalence of 18.4% (2.5% up to 61.1%) was obtained. Farms with prevalences (0–10%], (10–20%] and >20% were identified, with differences in seroconversion in the same prevalence group between farms and age ranges. Non-vaccinated (nV) and vaccinated (V) animals were included in the second sampling session. Higher levels of antibodies were detected in V animals older than 12 months, with considerable variations between age ranges and farms. Our results describe the current PTB status of the Canary Islands’ goat farming. Furthermore, new insights on the effect of the farm prevalence on seroconversion in V animals are provided, although further studies are needed to evaluate the multiple factors affecting the immune response to anti-MAP vaccination. Full article

Bovine tuberculosis is caused by Mycobacterium bovis, a member of the M. tuberculosis complex of mycobacterial species that cause tuberculosis in humans and animals. Diagnosis of bovine tuberculosis has relied on examinations of cell-mediated immune responses to M. bovis proteins using tuberculin skin testing and/or interferon gamma release assays. Even when using these methods, disease detection during the earliest phases of infection has been difficult, allowing a window for cattle-to-cattle transmission to occur within a herd. Alternative means of diagnosis could include methods to detect M. bovis or M. bovis DNA in bodily fluids such as nasal secretions, saliva, or blood. During the first 8 weeks after experimental aerosol infection of 18 calves, M. bovis DNA was detected in nasal swabs from a small number of calves 5, 6, and 8 weeks after infection and in samples of saliva at 1, 7, and 8 weeks after infection. However, at no time could culturable M. bovis be recovered from nasal swabs or saliva. M. bovis DNA was not found in blood samples collected weekly and examined by real-time PCR. Interferon gamma release assays demonstrated successful infection of all calves, while examination of humoral responses using a commercial ELISA identified a low number of infected animals at weeks 4–8 after infection. Examination of disease severity through gross lesion scoring did not correlate with shedding in nasal secretions or saliva, and calves with positive antibody ELISA results did not have more severe disease than other calves. Full article