Discrimination between Mycobacterium tuberculosis and Mycobacterium bovis using Fourier transform infrared spectroscopy.

Improving disease resistance in cattle relies on informed breeding and vaccine development, both depend on our understanding of immune mechanisms in cattle. However, transcriptomic studies of bovine immune responses often show considerable variability due to differences in tissue type, pathogen, time point, and experimental design, limiting the generalizability. Meta-analysis integrates multiple transcriptomic studies to identify consistent gene expression patterns and enhance statistical power. We integrated bovine RNA-seq datasets using immune-response specific keywords, species constraints, and high-throughput sequencing filters to prioritize biologically comparable and meta-analysis-ready studies. Specifically, in this study, we performed a meta-analysis of four bovine transcriptomic datasets to identify immune-related differentially expressed genes (DEGs) in Bos taurus. These datasets showed consistent results across analyses and represent immune responses related to mycobacterial infections (Mycobacterium bovis and Mycobacterium avium subsp. paratuberculosis), making them suitable for combined analysis. Our pipeline included FastQC, Trimmomatic, Bowtie2, SAMtools, FeatureCounts, DESeq2, and MetaRNASeq, identifying 28 DEGs (12 upregulated and 16 downregulated). We identified key immune-related genes (IL1A, RGS2, RCAN1, ZBP1, TIMD4, PPARG, TLR10, and ACP5) with known regulatory roles in immunity. KEGG enrichment analysis revealed involvement in necroptosis, osteoclast differentiation, oxytocin signaling, and cGMP-PKG signaling pathways, associated with inflammatory cell death, cytokine signaling, and immune cell differentiation. Using reproducible transcriptomic signals across systematically selected bovine immune datasets rather than relying on single-experiment analyses, we provide a robust meta-analytic framework. This meta-analysis enhances our understanding of conserved immune signaling mechanisms in cattle for identifying conserved immune mechanisms with broader biological and translational relevance.

Mycobacterium bovis causes bovine tuberculosis (bTB), a chronic infectious disease with significant veterinary, public health, and economic consequences. The interferon-gamma (IFN-γ) assay is increasingly used alongside the Single Intradermal Comparative Tuberculin Test (SICTT) in Ireland's national bTB eradication programme, but age-specific patterns associated with IFN-γ positivity or post-mortem visible lesion detection (VLD) have not been fully characterised. This retrospective cohort study includes 267,674 SICTT-negative cattle tested with IFN-γ between May 2019 and December 2023 in high-risk Irish herds. Mixed-effects logistic regression models quantify associations between age and (i) IFN-γ positivity and (ii) VLD at slaughter among IFN-γ-positive cattle. Models adjust for sex, herd type, prior inconclusive SICTTs, number of prior 'risky' SICTT tests, and herd-level breakdown size (% of animals positive). Overall, 9.6% of SICTT-negative cattle test positive to IFN-γ. Our findings show that IFN-γ positivity increases with age, peaks in cattle aged 4-6 years, plateaus until 8 years, and declines thereafter. Relative to beef breeding herds, dairy, mixed, and 'other' herd types are associated with higher IFN-γ positivity, as is a history of prior inconclusive SICTTs, and fewer prior 'risky' SICTT exposures. Among IFN-γ-positive cattle, 21.9% exhibit VLD at slaughter. VLD positivity shows a U-shaped relationship with age, highest in the youngest (0-2 years), reducing in cattle aged 2-4, then increasing linearly to oldest (>8 years) cattle. The VLD odds are approximately half in dairy herds compared with beef breeding herds and are elevated in herds in the largest quartile of breakdowns (>6.25% of animals positive). The interpretation of these results should consider that IFN-γ-positivity and VLD likely reflect different stages of bTB infection, with early immune responses detected ante-mortem and visible lesions at post-mortem representing later stage disease; the absence of visible lesions therefore does not exclude M. bovis infection. It appears that age-specific IFN-γ positivity and VLD in high-risk herds are likely shaped by production systems, prior risky SICTT exposures, and herd-level outbreak dynamics rather than simple cumulative risk. The IFN-γ testing helps to identify infected cattle missed by SICTT, particularly in the early infection or large herd breakdowns and serves to support targeted, risk-based deployment to optimize Ireland's bTB eradication programme.

Mycobacterium avium subsp. paratuberculosis (MAP) and the disease it causes in cattle were first officially documented in Colombia in 1924 and originated from imported cattle. Since then, paratuberculosis (PTB) has received little attention, and there is currently no literature offering an updated overview of this disease in Colombia. This scoping review aims to synthesize the evidence and information compiled over the last 100 years to understand the epidemiology and public health response to PTB in Colombia. Using four academic databases, we retrieved articles that mentioned MAP/PTB in Colombia, had no language limitations, and were published between 1924 and 2024. In addition, we manually searched for proceedings from the 3rd to 16th International Colloquia on Paratuberculosis for existing published primary studies. A total of 48 original studies on MAP/PTB were identified and analyzed. Most related studies have been conducted during the past two decades and have focused primarily on cattle (89.4 %). ELISA (59.6 %) and PCR (42.6 %) were the most commonly used diagnostic methods. The study designs were predominantly descriptive or cross-sectional, with no cohort or casecontrol studies reported. Despite being a notifiable disease since 2015, no research has addressed MAP detection in food or humans. The findings revealed a fragmented research landscape, with significant gaps in diagnostics, epidemiology, molecular characterization, and public health impact. Policy issues are discussed, including the absence of legal frameworks to coordinate responses to the disease and its relationship with bovine tuberculosis. Colombia should acknowledge the presence of MAP/PTB within the country and address it as a national priority.

Multiple cold abscesses of the penis due to Mycobacterium bovis following BCG therapy.

Antibiotic-resistant tuberculosis is a worldwide health threat responsible for hundreds of thousands of deaths each year. The continuous escalation of multidrug resistance demands efforts to identify effective novel therapy approaches against mycobacteria, where selective pressure on the pathogen is not the only treatment goal. In this perspective, Sertoli cells (SCs), originally considered as "sustentacular cells" in the testis, have been elevated to cells of the immune system owing to their capacity to modulate the immune response. As such, they express immunoregulatory factors with a remarkable phagocytic capacity and anti-bacterial activity. The aim of the present study was to explore whether SCs could play a role in the treatment of mycobacteria infections that, to the best of our knowledge, has never been reported before. Neonatal porcine SCs monolayer were co-cultured with three different concentrations of Mycobacterium bovis Bacillus Calmette and Guerin for 48h. The phagocytic activity of SCs and the interaction between mycobacteria and SCs have been investigated by the uptake experiment and electron microscopy analysis, respectively. The intra- and extracellular antibacterial activities of SCs have been evaluated by measuring their killing performances. SCs were shown capable of phagocyting mycobacteria while remaining viable and maintaining ultrastructure integrity. Even at higher mycobacterial concentrations, SCs demonstrated an intracellular killing activity with a Logarithmic reduction of 0.4 Log10 CFU/ml up to 7 days and an extracellular killing activity with a Logarithmic reduction of 1 Log10 CFU/ml up to 10 days post-infection. This study provided evidence that SCs could be a potentially valuable therapeutic tool for the treatment of mycobacterial infections, such as tuberculosis, by exerting a direct and indirect antibacterial action.

Systemic BCG administration induces transcription factor signature in CD4+ T cells that cooperates with IL-12 signaling to drive antiviral Th1 differentiation.

Infections with Mycobacterium bovis can lead to clinical tuberculosis in many mammals. Here, we describe M. bovis infections in 4 of 7 cats from 1 household in Germany. These cats had respiratory disorders at intervals of several months. Two of 4 euthanized animals (cats 3 and 4) were submitted for postmortem examination; lungs failed to collapse and were firm in both cats. In cat 4, a severely enlarged pulmonary lymph node was found, as well as small white granulomas in the spleen, liver, and kidney. Bacterial cultivation identified M. bovis spoligotype SB0120 as the causative pathogen in cats 3 and 4. Molecular genetic fine typing revealed that this genotype had not been reported previously in animals or humans in Germany. Serum from cat 4 shortly before euthanasia, and from cats 5–7, were tested for TB-specific antibodies by ELISA. Cat 4 was strongly positive. In contrast, cats 5–7 were negative and remained negative 4 mo later. Based on our case series, tuberculosis should be considered as a differential diagnosis in pet animals, even in countries that are officially free of the disease. A lack of awareness about tuberculosis could increase the risk of zoonotic infections with M. bovis—for both owners and other animals living in affected households.

Mycobacterium bovis, the causative agent of bovine tuberculosis, poses public health risks through animal-derived products. This study evaluated the genetic diversity of M. bovis in 103 cattle tissue samples from tuberculin-positive or lesion-suspected slaughtered animals and 435 randomly collected dairy samples (335 milk, 100 traditional cheese) in northwest Iran. Positive samples were genotyped using a 12-locus MIRU-VNTR panel. Genetic diversity indices were 0.99 in tissue samples, 0.61 in milk, and 0.83 in cheese. The MTUB21 locus exhibited the highest allelic diversity (h = 0.73), whereas QUB26 showed the lowest (h = 0.16). Minimum spanning tree analysis revealed no well-supported source-specific clusters, indicating substantial allelic and genotypic diversity across sample types. Among the genotyped samples, 8.33% belonged to the caprae genotype, the most frequent lineage in this dataset. These findings provide insight into the population structure and genetic relationships of M. bovis in the region, supporting continued molecular surveillance within a One Health framework for tuberculosis control.

Bovine tuberculosis(bTB), caused by Mycobacterium bovis, is a zoonosis that threatens public health and causes substantial economic losses in livestock. The suboptimal Escherichia coli-expressed recombinant proteins limit the diagnostic performance of current bTBserological tests. To overcome this limitation, we evaluated Mycolicibacterium smegmatis as an expression host capable of producing recombinant antigens with post-translational modifications comparable to those of M. bovis. Ten antigen candidates were individually expressed in E. coli using the pET-26b( +) vector and in M. smegmatis using the pSOΔBam vector. Their diagnostic performance was evaluated using anenzyme-linked immunosorbent assay(ELISA) with plasma samples from interferon-gamma release assay (IGRA)-negative (n = 30) and -positive (n = 46) cattle in South Korea, followed by receiver operating characteristic (ROC) curve analysis. Among the single antigens, LprA expressed in M. smegmatis demonstrated diagnostic performance comparable to that ofthe well-established antigen MPB70 (sensitivity: 50.0%, specificity: 96.6%, AUC: 0.791). In addition, several M. smegmatis-derived antigens showed higher concordance with the IGRA results, as assessed by Cohen's kappa and Fisher's exact tests, and a stronger association between age and antigen-specific antibody responses was observed among IGRA-positive cattle. Moreover, a multiple logistic regression model incorporating eight antigens, including those derived from both hosts, achieved high predictive accuracy for IGRA results (sensitivity: 87.0%, specificity: 100%, AUC: 0.991). These findings suggest that M. smegmatis is a promising host for identifying novel antigens and that a multi-host strategy may improve bTB serodiagnosis.

Non-tuberculous mycobacteria (NTM), once regarded as environmental pathogen, are now recognized as opportunistic pathogens capable of infecting humans and animals, interfering with the diagnosis of bovine tuberculosis and posing significant therapeutic challenges in humans. This study aimed to determine the prevalence of NTM in bovines and to characterize circulating species using genetic and protein mass profiling methods. A cross-sectional study was conducted with a total of 409 bovine samples, including nasal swabs (154), faecal samples (157), milk (50) and lung tissues (48) collected from farms and slaughterhouses across Tamil Nadu. Samples were processed using standard bacteriological protocols and acid-fast isolates were confirmed by PCR targeting the hsp65 gene, followed by partial gene sequencing and MALDI-TOF MS for species identification. The overall prevalence of NTM was 2.2% (9/409). Identified species included Mycobacterium kansasii, Mycobacterium asiaticum, Mycobacterium kyorinense, Mycolicibacterium fortuitum and Mycolicibacterium smegmatis. All species identified in this study, except M. kansasii, are reported for the first time from animals in India, and M. kyorinense is reported for the first time from animals globally. Sequencing and MALDI-TOF MS showed good concordance for species identification. Antimicrobial susceptibility testing was performed using the broth microdilution method against selected first and second line antimycobacterial drugs, revealing diverse resistance patterns, with several isolates exhibiting resistance to first-line anti-tuberculosis drugs. This study provides novel data on NTM prevalence and species diversity in bovines, highlighting their zoonotic potential and emphasizing the need for improved surveillance, accurate diagnostics and antimicrobial stewardship in livestock-public health interfaces.

Mycobacterium bovis, the causative agent of bovine tuberculosis, infects and persists within macrophages, triggering pro-inflammatory responses. While these mechanisms are well characterized for Mycobacterium tuberculosis, less is known about host responses to M. bovis. Inflammasome activation and IL-1β production have been linked to ESAT-6, a substrate of the ESX-1 secretion system present in both species. Here, we examined inflammasome activation in bovine macrophages infected with the virulent M. bovis strain Mb04-303. M. bovis AF2122/97 and NCTC10772 upregulated IL-1β transcription, whereas Mb04-303 and BCG did not. Unexpectedly, deletion of the genes encoding ESAT-6 and CFP-10 from Mb04-303 enhanced inflammasome activation, as evidenced by increased NLRP3 and IL-1β transcription. Complementation with either wild-type ESAT-6/CFP-10 or the T63A ESAT-6 variant restored downregulation of the response, indicating that this substitution does not alter inflammasome modulation. In contrast, deletion of ESAT-6/CFP-10 from an attenuated M. bovis vaccine candidate reduced IL-1β transcription. No differences were observed between M. tuberculosis H37Rv and its ESAT-6-deficient mutant in bovine macrophages. Together, these findings demonstrate that ESAT-6/CFP-10-mediated modulation of inflammasome activation in bovine macrophages is highly dependent on the mycobacterial genetic background.

Bovine tuberculosis is listed among the top three animal diseases that cause major animal and public health concerns in Ethiopia. Knowledge, attitude and practices (KAPs) of farmers towards bovine tuberculosis in Ethiopia remain insufficiently studied, especially among local cattle owners. Therefore, this study aimed to assess the level of cattle owners' KAPs. A cross-sectional study with 200 randomly selected study participants was carried out using a face-to-face interview from December 2023 to May 2024 in and around Nekemte town, western Ethiopia. The statistical analysis was performed using Stata version 16. Chi-square analysis was used to assess the association between independent variables and owners' KAPs, and multivariable logistic regression analysis was used to identify potential predictor variables. Among the total respondents, 34.5% and 32.0% of them knew about bovine tuberculosis and the zoonotic importance of it, respectively, while 18.8% of the respondents knew that the causative agent of bovine tuberculosis is bacteria. The KAPs of the respondents were associated with their education level. Those respondents who attended college/university and secondary education were 5.76 (1.46-22.66) and 3.26 (1.03-12.08) times more knowledgeable about bovine tuberculosis than those who did not attend a formal education. Those respondents who had completed college/university had 7.34 (2.33-23.11), secondary school had 3.34 (1.15-9.66), and primary school had 4.54 (1.48-13.89) times more likely to have a desirable attitude than those who did not attend formal education. With regard to practices, those respondents with a college/university, secondary or primary education had 6.74 (1.97-23.10), 3.53 (1.11-11.27) and 5.13 (1.52-17.32) times more appropriate practices, respectively, than those who did not attend a formal education. The respondents had a low level of KAPs regarding bovine tuberculosis in and around Nekemte town, Ethiopia. Raising awareness through education and training campaigns, both in human and animal health sectors, using a one health approach, is necessary.

Bovine tuberculosis (bTB) has been a major cause of morbidity and mortality in farm animals and the recent surge of Mycobacterium tuberculosis complex (MTC) in developing countries poses a serious threat to public and animal health. This study aimed to assess the herd-level prevalence and associated risk factors of bovine TB in cattle in northeast regions of Bangladesh. A total of 485 dairy samples (385 from dairy milk and 100 from vendor's milk) were tested by Polymerase Chain Reaction (PCR) and indirect ELISA (enzyme-linked immunosorbent assay) technique at 16 Upazilas from 4 districts in the Sylhet division of Bangladesh. Genomic DNA extracted from milk samples were targeted at IS6110 and RV1506c genomic fragments for PCR. Among the 385 milk samples tested, 15 milk samples were positive for Mycobacterium genus by PCR (3.90%, 95% CI: 1.95-5.84). Also, 10 samples were found to be positive for M. bovis and the prevalence was 2.60% (95% CI: 1.00-4.19) and only 2 milk samples were positive for M. tuberculosis by PCR whose prevalence was 0.52% (95% CI: 0.00-1.24) respectively in individual milk samples. In vendor's milk sample, the trend was lowered for each bacterium and indirect ELISA results agreed with a similar pattern of prevalence. Cows having chronic cough was one of the significant risk factors of herd-level prevalence. Findings from this study necessitate a comprehensive program for TB surveillance of associated risk factors or protective factors in human, environment and animal interface.

Commentary on the potential effects of infection with Mycobacterium bovis during the first days of life on the immune response to, and performance of diagnostics for the detection of, infection with M. bovis.

Type II toxin–antitoxin (TA) systems are significantly expanded in the Mycobacterium tuberculosis complex; however, the functional role of the VapBC40 system in Mycobacterium bovis (M. bovis) pathogenesis remains poorly characterized. This study aimed to investigate the role of VapBC40 in mycobacterial virulence and evaluate its potential as a target for rational vaccine attenuation. We performed evolutionary analysis and yeast two-hybrid assays to characterize VapBC40 system specificity, conducted in vitro macrophage infection models and in vivo murine studies to assess virulence contribution, and evaluated the immunoprotective efficacy of a VapC40 knockout strain. Evolutionary analysis revealed progressive sequence conservation and stringent homologous pairing specificity within the VapBC40 system. The VapC40 toxin correlates with enhanced intracellular bacterial survival, increased host cell death, and more severe pulmonary pathology with systemic dissemination. Based on these findings, we evaluated the vaccine potential of a vapC40 knockout strain. Immunization with this attenuated strain elicited a Th1 cellular immune response, characterized by enhanced IFN-γ production and increased frequency of CD4+IFN-γ+ T cells. Upon challenge with virulent M. bovis, the knockout strain conferred superior protection compared to the conventional BCG vaccine, significantly reducing lung pathology and restricting extrapulmonary bacterial dissemination. Although the molecular mechanisms underlying VapC40-mediated effects remain to be fully elucidated, our findings suggest an important role of the VapBC40 system in mycobacterial-host interactions and support its potential as a target for next-generation tuberculosis vaccine development.

Host transcriptional responses identify putative diagnostic biomarkers for bovine tuberculosis in cattle and buffalo.

A systematic review of machine learning approaches to bovine tuberculosis in cattle.

Intravesical Bacillus Calmette-Guérin (BCG) therapy is an established treatment for non-muscle-invasive bladder cancer. Although systemic BCG infection is rare, infectious aortic aneurysm is a potentially fatal complication. A man in his 70s underwent transurethral resection of a bladder tumor followed by intravesical BCG therapy. One year later, computed tomography revealed a saccular abdominal aortic aneurysm with extensive periaortic inflammation and an iliopsoas abscess. Polymerase chain reaction analysis confirmed Mycobacterium bovis BCG infection. Despite antituberculosis therapy, aneurysmal rupture with abscess progression occurred, necessitating prosthetic graft replacement with omental flap coverage. The patient recovered without recurrence after prolonged therapy. BCG-related infectious aortic aneurysm may develop even in the absence of fever or marked inflammatory response. Clinicians should suspect and consider early CT evaluation in patients with a history of intravesical BCG therapy when unexplained retroperitoneal or vascular abnormalities are identified, regardless of inflammatory status.

A versatile plasmid platform for auxotrophic complementation in attenuated Mycobacterium bovis BCG.