Bovine tuberculosis in India: The need for One Health approach and the way forward

Quantitative Proteome Analysis of Plasma Extracellular Vesicles Identifies Three Proteins with Potential Diagnostic Value for Mycobacterium bovis Infection in Cows

Bovine tuberculosis (bTB) is a zoonotic disease that affects cattle and human health. Although the tuberculin skin test (TST) is the main detection method, there is a need for simpler on-farm tests using fluid samples. This study analyzed plasma extracellular vesicles (EVs) from two cow groups (Cohort A, 15 negative, 22 positive; Cohort B, 28 negative, 40 positive) to explore bTB indicators using proteome profiling. Among the 756 proteins, 217 (Cohort A) and 233 (Cohort B) showed differences between healthy and infected cows, with 47 consistently dysregulated in both groups. These proteins were related to tuberculosis, neutrophil extracellular trap formation, and antigen processing and presentation pathways. Notably, three proteins, HSPA8, B2M, and HRG, were confirmed as bTB indicators using multiple methods, including least absolute shrinkage and selection operator (Lasso) regression selection, western blot (WB), and enzyme-linked immunosorbent assay (ELISA) validation with an independent cohort (Cohort C). This study identifies plasma EV biomarkers for bTB infection, offering insights for bTB detection.

Prevalence of tuberculosis in bovines in Pakistan during 2000-2024: a systematic review and meta-analysis

Background

Bovine tuberculosis (bTB) primarily caused by Mycobacterium bovis (M. bovis), is a globally prevalent zoonotic infectious disease of cattle and other livestock and wildlife species. Pakistan is the fourth-largest milk-producing country in the world, with approximately 212 million animals. Livestock farming provides a livelihood for almost 8 million families. Moreover, there is currently no effective control program and national data in place. Therefore, we constructed a first meta-analysis on the prevalence of bovine tuberculosis in Pakistan. This study aimed to provide an overview of bovine tuberculosis in this country and identify the risk factors associated with its prevalence.

Methods

We searched Science Direct, Pubmed, Base, Green File-Poly U Library, Google Scholar, and additional articles were also identified manually from reference lists of articles generated in database search, systemically for papers that presented bTB prevalence data, published in English language between January 1, 2000, and April 30 2024. A total of 35 published articles were selected for inclusion in the meta-analysis.

Results

The estimated overall prevalence of bTB was found to be 6.06% [95% CI: 4.67-7.87]. Cattle were more susceptible to infection, with a higher prevalence (6.44% [95% CI: 4.04-10.26]) compared to buffalo (5.54% [95% CI: 3.13-9.81]). The prevalence determined by PCR (5.65% [95% CI: 3.33-5.98]) was much similar to that of TST (5.61% [95% CI: 4.20-7.50]) with no significant difference. Milk samples showed the highest prevalence (14.66% [95% CI: 7.38-29.11]), particularly due to the consumption of unpasteurized milk, improper handling of dairy products and suckling by calves from the infected cows. Furthermore, the analysis considered effect of various potential risk factors (age, weight, breed, body condition score, herd size, animal status) along with different geographical factors (longitude, latitude, altitude, humidity, rainfall, temperature, climate) associated with bTB prevalence, which should be considered when developing future disease surveillance and control programs.

Conclusion

In Pakistan bTB was widely distributed throughout the country, as a neglected zoonotic disease. Long-term disease prevalence monitoring should be recommended along with the need to improve diagnostic techniques, enhance farm management practices, and implement targeted surveillance to protect both animal and public health.

A bovine pulmosphere model and multiomics reveal early host response signature in tuberculosis

Early interactions between tubercle bacilli and lung cells are critical in tuberculosis (TB) pathogenesis. Conventional two-dimensional cell cultures fail to replicate the multicellular complexity of lungs. We introduce a three-dimensional pulmosphere model for Mycobacterium tuberculosis infection in bovine systems, demonstrating through comprehensive transcriptome and proteome analyses that these multicellular spheroids closely mimic lung cell diversity, interactions, and extracellular matrix (ECM) composition. Cell viability, hypoxia, and reactive oxygen species assessments over three weeks confirm the model's suitability. To establish infection, we employed M. bovis BCG-an attenuated vaccine strain, and M. tuberculosis H37Rv-a laboratory adapted human clinical strain that is attenuated for cattle infection compared to M. bovis. Both infection upregulated key host pathways; however, M. tuberculosis induced distinct responses, including enhanced ECM receptors expression, neutrophil chemotaxis, interferon signaling, and RIG-1 signaling. A six genes/protein signature- IRF1, CCL5, CXCL8, CXCL10, SERPINE1, and CFB -emerges as an early host response marker to M. tuberculosis infection. Infection with virulent M. bovis and M. orygis revealed a shared upregulated gene signature across Mycobacterium tuberculosis complex species, but with pathogen-specific variations. This study presents a robust ex vivo bovine pulmosphere TB model with implications in biomarkers discovery, high-throughput drug screening, and TB control strategies.

A disposable, portable electrochemical immunosensor for rapid in situ detection of bovine tuberculosis

This contribution describes the development of a simple, fast, cost-effective, and sensitive impedimetric immunosensor for quantifying bovine tuberculosis (TB) in bovine serum samples. The construction of the immunosensor involved immobilizing the purified protein derivative (PPD) of M. bovis onto a screen-printed electrode that was modified with gold nanoparticles (AuNPs) and a polypyrrole (pPy) film synthesized electrochemically. The immunosensor exhibited a linear range from 0.5 μg mL-1 to 100 μg mL-1 and achieved a limit of detection (LD) of 100 ng mL-1 for the detection of anti-M. bovis antibody. The recovery percentages obtained in bovine serum samples were excellent, ranging between 98 % and 103 %. This device presents several advantages over alternative methods for determining TB in bovine serum samples. These include direct, in situ measurement without the need for pre-treatment, utilization of small volumes, thus avoiding harmful solvents and expensive reagents, and portability. In addition, the immunosensor exhibits both physical and chemical stability, retaining effectiveness even after 30 days of modification. This allows simultaneous incubations and facilitates large-scale detection. Hence, this immunosensor presents itself as a promising diagnostic tool for detecting anti-M. bovis antibodies in bovine serum. It serves as a viable alternative to tuberculin and ELISA tests.

Systematic review of knowledge, attitudes, and practices of dairy farmers and consumers towards bovine tuberculosis in low- and middle-income countries

Bovine Tuberculosis (bTB), caused by Mycobacterium bovis, is a neglected zoonotic disease primarily associated with cattle. The incidence of bTB is highest in low-income settings with high cattle density and unpasteurised dairy consumption. Smallholder dairy farming has steadily grown in low- and middle-income countries (LMICs) with limited professional support for adequate bTB surveillance and risk mitigation. Several studies have explored the knowledge, attitudes, and practices (KAP) of milk value chain stakeholders towards bTB in LMICs, but this evidence has not been collated and synthesised. We conducted a systematic review to determine what is known, believed, and done in relation to bTB among dairy producers and consumers in LMICs. We performed a systematic search of studies in OVID Medline, Scopus and CABI on 11 September 2023. KAP data were summarised using narrative synthesis and forest plots. We retrieved 2763 articles, retaining 51 for the review. Only studies from Africa (n = 38) and Asia (n = 13) met the eligibility criteria. Most populations reported awareness of human tuberculosis and knew it could be treated, but there was limited awareness of bTB and its zoonotic potential. Knowledge of bTB transmission routes and bTB mitigation varied across populations, and risky practices were also variable. Inconsistencies in study design and survey tools suggest some results may have a mid- to high-risk of bias. Awareness of bTB is surprisingly low among African and Asian populations with high bTB exposure risk, possibly due to the long-standing divide between animal and human health messages that has obscured the One Health implications of bTB. Addressing bTB in LMICs requires a structural One Health approach and standard KAP survey tools to adequately explore the socio-cultural, political, and economic processes and drivers favouring bTB spread and persistence.

Tuberculosis in wild animals in India

India is renowned for its complex megadiverse ecosystems and abundant biodiversity. Bovine tuberculosis (bTB) often remains synonymous with Mycobacterium bovis infection in cattle. The domain of tuberculosis (TB) among wild animals, induced by members of the Mycobacterium tuberculosis complex organisms (MTBC), is often underexplored and underreported in India. Within this context, instances of wild animal tuberculosis (wTB) have manifested across both captive and free-roaming animals. The sources contributing to wTB in animals can be human, animal, or environmental factors, thus illuminating the complex transmission pathways. The diagnosis of wTB continues to pose a formidable challenge, a consequence of the expansive taxonomic diversity in both the host and the pathogen. Complications inherent in acquiring samples from wildlife, the absence of standardized diagnostic protocols, limited insights into infection prevalence, and resource constraints compound diagnosis. Amidst these, adopting the comprehensive One Health paradigm surfaces as an imperative, accentuating the interconnectedness bridging human, animal, and environmental health. Recognizing key stakeholders and fostering intersectoral collaboration to provide enhanced diagnostic techniques driven by skilled personnel and advanced infrastructure play pivotal roles in a comprehensive strategy. Additionally, leveraging vaccination efforts contributes to effective control. A national wTB surveillance program is a cornerstone, ensuring an integrated and holistic approach to disease management. Through this review, we delve into the current landscape of wTB in India, unveiling its multifaceted challenges, and further explore the multifarious strategies that the One Health approach proffers in this dynamic endeavor.

A one health-focused literature review on bovine and zoonotic tuberculosis in Pakistan from the past two decades: challenges and way forward for control

Bovine tuberculosis (bTB), caused by Mycobacterium bovis (M. bovis), is a globally prevalent zoonotic infectious disease. World Organization for Animal Health (WOAH) estimates indicate that up to 10% of the total human TB cases in developing countries are attributed to M. bovis. Pakistan ranks 4th in global milk production with a livestock population of over 212 million animals. Over 8 million families are involved in raising these animals as a means of livelihood. To date, there is an absence of national-level data on the prevalence of bTB and an effective control program is still lacking. The multifaceted impacts and substantial economic losses render addressing bTB a daunting, but highly important challenge. In this review, we summarise all the freely available literature on M. bovis infection from Pakistan using Google scholar and PubMed databases. A total of 40 animal studies were identified using search terms: "bovine tuberculosis in Pakistan, bTB, Pakistan, Mycobacterium bovis in Pakistan, M. bovis in Pakistan"; while seven human studies were identified using the terms: zoonotic tuberculosis in Pakistan', 'M. bovis in humans Pakistan', 'zTB in TB patients in Pakistan". We have summarized all these studies to identify critical risk factors involved in transmission of bTB among animals and humans. Despite lack of comprehensive and geographically representative studies, the literature suggests a varying prevalence of bTB in animals, ranging from as low as 2% to as high as 19%. Regarding zTB prevalence in humans, estimates range from 1.5% to 13% in high-risk group of farm and abattoir workers, with notably higher percentages in extra-pulmonary TB cases. The review also addresses the challenges that Pakistan faces in formulating an effective policy for the control and eradication of bTB. We conclude with one-health based recommendations as a way forward for controlling TB caused by M. bovis in cattle and humans.

Unveiling insights into bovine tuberculosis: A comprehensive review

The frequent zoonotic disease known as "bovine tuberculosis" is brought on by the Mycobacterium bovis bacteria, which can infect both people and animals. The aim of this review article is to provide an explanation of the etiology, history, epidemiology, pathogenesis, clinical symptoms, diagnosis, transmission, risk factors, public health importance, economic impact, treatment, and control of bovine tuberculosis. Primarily, bovine tuberculosis affects cattle, but other animals may also be affected. Bovine tuberculosis is present throughout the world, with the exception of Antarctica. Cattle that contract bovine tuberculosis might suffer from a persistent, crippling illness. In the early stages of the disease, there are no symptoms. The tuberculin test is the primary method for detecting bovine tuberculosis in cows. Depending on its localized site in the infected animal, M. bovis can be found in respiratory secretions, milk, urine, feces, vaginal secretions, semen, feces, and exudates from lesions (such as lymph node drainage and some skin lesions). This illness generally lowers cattle productivity and could have a negative financial impact on the livestock business, particularly the dairy industry. The most effective first-line anti-tuberculosis chemotherapy consists of isoniazid, ethambutol, rifampin, and streptomycin. Second-line drugs used against bovine tuberculosis include ethionamide, capreomycin, thioacetazone, and cycloserine. To successfully control and eradicate bovine tuberculosis, developed nations have implemented routine testing and culling of infected animals under national mandatory programs.

Mapping Bovine Tuberculosis in Colombia, 2001-2019

INTRODUCTION

Bovine tuberculosis is a zoonotic disease of significant impact, particularly in countries where a pastoral economy is predominant. Despite its importance, few studies have analysed the disease's behaviour in Colombia, and none have developed maps using geographic information systems (GIS) to characterise it; as such, we developed this study to describe the temporal-spatial distribution of bovine tuberculosis in Colombia over a period of 19 years.

METHODS

A retrospective cross-sectional descriptive study, based on reports by the Colombian Agricultural Institute (ICA), surveillance of tuberculosis on cattle farms in Colombia from 2001 to 2019 was carried out. The data were converted into databases using Microsoft Access 365®, and multiple epidemiological maps were generated with the QGIS® version 3.36 software coupled to shape files of all the country's departments.

RESULTS

During the study period, 5273 bovine tuberculosis cases were identified in multiple different departments of Colombia (with a mean of 278 cases/year). Regarding its temporal distribution, the number of cases varied from a maximum of 903 cases (17.12% of the total) in 2015 to a minimum of 0 between 2001 and 2004 and between 2017 and 2019 (between 2005 and 2016, the minimum was 46 cases, 0.87%).

CONCLUSIONS

GIS are essential for understanding the temporospatial behaviour of zoonotic diseases in Colombia, as is the case for bovine tuberculosis, with its potential implications for the Human and One Health approaches.

Seroprevalence and risk factors associated with bovine tuberculosis in cattle in Eastern Bhutan

Bovine tuberculosis (bTB) is a chronic zoonotic disease affecting cattle of all age groups including wild animals. It poses a significant threat to public health and high economic losses to dairy farmers. While the disease has been eradicated from most of the developed countries through extensive surveillance, testing and culling strategy, it is endemic in Africa, Asia, and the Middle East countries. Currently, there is limited research regarding the prevalence of bTB in cattle in Bhutan. This study aimed to determine the seroprevalence of bTB in cattle in six districts of eastern Bhutan. A two-stage probability proportional to size (PPS) sampling strategy was used to determine the number of animals from which serum samples needed to be collected in each district and sub-district. All farms and cattle for sampling were randomly selected from the data in the annual livestock census of 2020. The samples were tested using bTB ELISA test kit. The seroprevalence and their 95% confidence intervals were calculated. Logistic regression models were constructed to assess the influence of various individual animal and environmental risk factors (breed, age, sex, source of animal, body condition scores of animals, respiratory system status) associated with sero-positivity in animals. The study revealed an apparent seroprevalence of 2.57% (25/971 cattle; 95% CI:1.58-3.57), with an estimated true seroprevalence of 0.91% (95% CI: 0.0-2.81). However, none of the variables were found to be significantly associated with bTB seroprevalence in cattle. We recommend, further sampling and employment of confirmatory testing to fully ascertain the extent of bTB in the cattle herds in eastern Bhutan for prevention and control.

The Establishment of a Novel γ-Interferon In Vitro Release Assay for the Differentiation of Mycobacterial Bovis-Infected and BCG-Vaccinated Cattle

BCG vaccination is increasingly reconsidered in the effective prevention of bovine tuberculosis (bTB). However, the primary challenge in BCG vaccination for cattle is the lack of a technique for differentiating between infected and vaccinated animals (DIVA). This study aimed to establish a novel DIVA diagnostic test based on an interferon-gamma in vitro release assay (IGRA). The plasmid encoding three differential antigens (Rv3872, CFP-10, and ESAT-6) absent in BCG genes but present in virulent M. bovis was previously constructed. Thus, a recombinant protein called RCE (Rv3872, CFP-10, and ESAT-6) was expressed, and an RCE-based DIVA IGRA (RCE-IGRA) was established. The RCE concentration was optimized at 4 μg/mL by evaluating 97 cattle (74 of which were bTB-positive, and 23 were negative) using a commercial IGRA bTB diagnostic kit. Further, 84 cattle were tested in parallel with the RCE-IGRA and commercial PPD-based IGRA (PPD-IGRA), and the results showed a high correlation with a kappa value of 0.83. The study included BCG-vaccinated calves (n = 6), bTB-positive cattle (n = 6), and bTB-negative non-vaccinated calves (n = 6). After 3 months post-vaccination, PPD-IGRA generated positive results in both vaccinated and infected calves. However, RCE-IGRA developed positive results in infected calves but negative results in vaccinated calves. In conclusion, this DIVA method has broad prospects in differentiating BCG vaccination from natural infection to prevent bTB.

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Origin of Antibiotics and Antibiotic Resistance, and Their Impacts on Drug Development: A Narrative Review

Antibiotics have revolutionized medicine, saving countless lives since their discovery in the early 20th century. However, the origin of antibiotics is now overshadowed by the alarming rise in antibiotic resistance. This global crisis stems from the relentless adaptability of microorganisms, driven by misuse and overuse of antibiotics. This article explores the origin of antibiotics and the subsequent emergence of antibiotic resistance. It delves into the mechanisms employed by bacteria to develop resistance, highlighting the dire consequences of drug resistance, including compromised patient care, increased mortality rates, and escalating healthcare costs. The article elucidates the latest strategies against drug-resistant microorganisms, encompassing innovative approaches such as phage therapy, CRISPR-Cas9 technology, and the exploration of natural compounds. Moreover, it examines the profound impact of antibiotic resistance on drug development, rendering the pursuit of new antibiotics economically challenging. The limitations and challenges in developing novel antibiotics are discussed, along with hurdles in the regulatory process that hinder progress in this critical field. Proposals for modifying the regulatory process to facilitate antibiotic development are presented. The withdrawal of major pharmaceutical firms from antibiotic research is examined, along with potential strategies to re-engage their interest. The article also outlines initiatives to overcome economic challenges and incentivize antibiotic development, emphasizing international collaborations and partnerships. Finally, the article sheds light on government-led initiatives against antibiotic resistance, with a specific focus on the Middle East. It discusses the proactive measures taken by governments in the region, such as Saudi Arabia and the United Arab Emirates, to combat this global threat. In the face of antibiotic resistance, a multifaceted approach is imperative. This article provides valuable insights into the complex landscape of antibiotic development, regulatory challenges, and collaborative efforts required to ensure a future where antibiotics remain effective tools in safeguarding public health.

Divergent proinflammatory immune responses associated with the differential susceptibility of cattle breeds to tuberculosis

Tuberculosis (TB) in the bovine is one of the most predominant chronic debilitating infectious diseases primarily caused by Mycobacterium bovis. Besides, the incidence of TB in humans due to M. bovis, and that in bovines (bovine TB, bTB) due to M. tuberculosis- indicates cattle as a major reservoir of zoonotic TB. While India accounts for the highest global burden of both TB and multidrug-resistant TB in humans, systematic evaluation of bTB prevalence in India is largely lacking. Recent reports emphasized markedly greater bTB prevalence in exotic and crossbred cattle compared to indigenous cattle breeds that represent more than one-third of the total cattle population in India, which is the largest globally. This study aimed at elucidating the immune responses underlying the differential bTB incidence in prominent indigenous (Sahiwal), and crossbred (Sahiwal x Holstein Friesian) cattle reared in India. Employing the standard Single Intradermal Tuberculin Test (SITT), and mycobacterial gene-targeting single as well as multiplex-PCR-based screening revealed higher incidences of bovine tuberculin reactors as well as Mycobacterium tuberculosis Complex specific PCR positivity amongst the crossbred cattle. Further, ex vivo mycobacterial infection in cultures of bovine peripheral blood mononuclear cells (PBMC) from SITT, and myco-PCR negative healthy cattle exhibited significantly higher intracellular growth of M. bovis BCG, and M. tuberculosis H37Ra in the crossbred cattle PBMCs compared to native cattle. In addition, native cattle PBMCs induced higher pro-inflammatory cytokines and signaling pathways, such as interferon-gamma (IFN-γ), interleukin-17 (IL-17), tank binding kinase-1 (TBK-1), and nitric oxide (NO) upon exposure to live mycobacterial infection in comparison to PBMCs from crossbred cattle that exhibited higher expression of IL-1β transcripts. Together, these findings highlight that differences in the innate immune responses of these cattle breeds might be contributing to the differential susceptibility to bTB infection, and the resultant disparity in bTB incidence amongst indigenous, and crossbred cattle.

Assessing and Prioritizing Zoonotic Diseases in Punjab, India: A One Health Approach

Zoonotic diseases have a significant impact on both human and animal health globally. The present study was planned to prioritize the zoonoses in Punjab state of India. To develop a zoonotic disease prioritization scoring system, a comprehensive approach has been taken, including literature review, key person interviews with animal health experts (n = 12) and medical professionals (n = 7), and nine focus group discussions (FGDs) with veterinary academicians, medical professionals, and field veterinary doctors. The scoring system comprises of seven major criteria, each assigned a weightage score (ws): prevalence/incidence of the disease (ws = 0.20), severity of illnesses in humans (ws = 0.18), epidemic potential (ws = 0.16), socio-economic burden (ws = 0.16), availability of effective control and prevention measures (ws = 0.15), inter-sectoral collaborations (ws = 0.1), and bioterrorism potential (ws = 0.05). The finalized scoring system, accompanied by a list of 15 selected zoonotic diseases, was implemented among a group of 23 professionals engaged in zoonoses research (n = 7), animal health (n = 10), and medical health (n = 6) to determine their prioritization. The zoonotic diseases prioritized for the Punjab (India) included, Brucellosis (0.70) > Rabies (0.69) > Anthrax (0.64) > Leptospirosis (0.62) = Toxoplasmosis (0.62) = Highly Pathogenic Avian Influenza (HPAI) (0.62) > Bovine tuberculosis (0.61) > Q fever (0.60) > Cysticercosis (0.59) > Listeriosis (0.58) > Crimean-Congo haemorrhagic fever (CCHF) (0.57) > Japanese encephalitis (0.56) = Echinococcosis (0.56) > Dermatophytosis (0.53) > and Scrub typhus (0.48), respectively. Higher priority is suggested for endemic zoonoses (e.g., brucellosis and rabies) as compared to those with epidemic potential (e.g., CCHF, HPAI etc.) in Punjab. Results of the current study will help in the development of targeted control and prevention strategies for zoonotic diseases in Punjab and other geographical regions facing similar challenges.

Specific identification of Mycobacterium bovis by Loop-Mediated Isothermal Amplification (LAMP) targeting the Region of Difference 12 (RD12) of the M. tuberculosis complex

Bovine tuberculosis is a prevalent zoonotic disease that causes high risks for production animals, dairy producers and consumers, together with significant economic losses. Thus, methods for easy, fast and specific detection of Mycobacterium bovis in small and medium-sized livestock under field conditions are very required. In this work, a Loop-Mediated Isothermal Amplification LAMP-PCR targeting the Region of Difference 12 (RD12) of M. bovis genome was designed for the purpose of identification. A set of six primers designed for the isothermal amplification of five different genomic fragments led to the specific identification of M. bovis from other mycobacterial species. A basic colorimetric reaction was clearly observed at first sight under natural light, indicating positive identification of M. bovis in a maximum of 30 min of isothermal amplification at 65 °C. The limit of detection was near 50 fg of M. bovis genomic DNA, corresponding approximately to 10 copies of the genome. •The proposed LAMP-PCR amplification of M. bovis genomic DNA might be performed by untrained laboratory personnel.•Specific identification of M. bovis LAMP is possible in 30 min at 65.. C using a simple water bath.•The basic colorimetric reaction for M. bovis identification could be observed with the naked eye under natural light.