Mycobacterium caprae transmission to free-living grey wolves (Canis lupus) in the Bieszczady Mountains in Southern Poland

Mycobacterial Interspersed Repeat Unit-Variable Number Tandem Repeat Typing of Mycobacterium avium Strains Isolated from the Lymph Nodes of Free-Living Carnivorous Animals in Poland

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms, of which some, especially those of the Mycobacterium avium complex (MAC), may be opportunistic animal and human pathogens. Infection with NTM can interfere with tuberculosis (TB) diagnosis and induce zoonoses, especially in immunocompromised individuals. Diseases caused by NTM have become more readily recognized; however, they are likely still underestimated. In this study, we identified and genotyped Mycobacterium avium strains that were isolated during TB monitoring among free-living carnivorous animals from southeastern Poland. In 2011-2020, lymph node samples from 192 such animals were tested for mycobacteria. A total of 41 isolates of M. avium strains were detected with the use of IS901, IS900, IS1245, and mycobacterial interspersed repeat unit-variable number tandem repeat (MIRU-VNTR) identification. Thirty-three were identified as M. avium subsp. avium. These strains were derived from 1 beech marten (Martes foina), 1 common buzzard (Buteo buteo), 2 European badgers (Meles meles), 3 wolves (Canis lupus), and 26 red foxes (Vulpes vulpes). One strain isolated from a wolf was identified as M. avium subsp. hominissuis. The results show the widespread occurrence of MAC bacilli in the studied environment and additionally comprise new data on the molecular characteristics of M. avium subspecies carried by free-living southeastern Polish carnivores.

Detection of Mycobacterium tuberculosis Complex Genetic Material in a Free-Living Brown Bear (Ursus arctos)

Mycobacterium tuberculosis complex (MTBC) has rarely been detected in bears (Ursidae). We describe detection of MTBC genetic material using a single-tube, high-multiplex PCR and fluorescence-based detection system in a throat swab collected from a free-living, problem individual during immobilization and telemetry collar deployment. Mycobacterial culture was negative in all samples.

The eradication of M. caprae tuberculosis in wild boar (Sus scrofa) in the Bieszczady Mountains, southern Poland – an administrative perspective

Introduction

Animal tuberculosis (TB) is a zoonotic disease caused by acid-fast bacteria belonging to the Mycobacterium tuberculosis complex (MTBC). Both animals and humans are susceptible to infection by the MTBC. Interspecies transmission is also possible, including to livestock and humans. In the years 1997–2013, many tuberculosis cases were recorded in European bison in the Bieszczady Mountains; more alarmingly, TB was also recorded in wild boar in the years 2013–2020.

Material and Methods

In the years 2013–2020, 104 wild boar from the Bieszczady Mountains were tested for TB through necropsy, mycobacterial culture, strain identification and spoligotyping.

Results

The microbiological examination confirmed TB in 46 wild boar; these infections were identified as M. caprae, spoligotype SB2391.

Conclusion

Free-living European bison are at risk of TB infection from wild boar carrying M. caprae. This situation also poses a risk to local cattle. There is a need for further activities aimed at monitoring the disease, preventing further transmission, and minimising the risk to public health.

Is serological monitoring a fit-for-purpose tool to assess the epidemiological situation of tuberculosis in the sylvatic species of European bison (Bison bonasus) in Poland?

Introduction

Bovine tuberculosis is one of the most dangerous zoonotic diseases. Despite the near-complete elimination of the disease from cattle breeding in Poland achieved in 2009, its re-emergence is now observed. Globally, the number of human cases is underestimated and the importance of free-living animals as reservoirs of tuberculosis is growing. As a species highly susceptible to Mycobacterium tuberculosis complex infection, the European bison (Bison bonasus) has a role in the transmission of the disease in Poland. The purpose of the investigation was to assess the epidemiological situation of tuberculosis in Polish European bison serologically.

Material and Methods

A total of 460 serum samples were collected from 436 European bison from 15 out of 26 national populations between 2013 and 2020. An M. bovis ELISA was used, and its sensitivity and specificity were assessed with an eyelid tuberculin skin test (TST) and interferon gamma release assay (IGRA).

Results

Mycobacterium bovis antibodies were detected in nine serum samples. The presence of antibodies was found in two animals from the Białowieża Forest (1.2% of the population), and one each from the Borecka Forest (2.4%) and the Warsaw Zoo (14.3%). One European bison among the 14 sampled (7.1%) from Smardzewice was positive on five occasions. Other samples from Smardzewice and the Bieszczady Mountains, where tuberculosis had previously been reported, were negative.

Conclusions

ELISA testing is an effective, easy and cost-efficient tool for monitoring of tuberculosis-naïve populations. Serological testing in tuberculosis control programmes can significantly improve the detection of infected herds. Antibody ELISAs may supplement TST and IGRA, but cannot replace them.

Intra-Palpebral Tuberculin Skin Test and Interferon Gamma Release Assay in Diagnosing Tuberculosis due to Mycobacterium caprae in European Bison (Bison bonasus)

Despite the threat posed by tuberculosis (TB) to the protected European bison (Bison bonasus), no validated TB tests exist for this species. This pilot study evaluates two tests based on detecting cellular immunity for this purpose: interferon gamma release assay (IGRA) and tuberculin skin test (TST). Ten animals were subjected to ante-mortem and post-mortem examinations. IGRA was performed using a commercial test, and the comparative TST was performed in the eyelids. The lesions were assessed post-mortem and material was collected for mycobacterial culture. The isolated strains were subjected to genotyping. At post-mortem examination, five out of ten individuals demonstrated both tuberculous lesions and positive culture results (Mycobacterium caprae). Compared to the palpebral TST, the findings of the IGRA are easier to interpret when diagnosing tuberculosis in European bison.

Pathogens with potential impact on reproduction in captive and free-ranging European bison (Bison bonasus) in Poland - a serological survey

BACKGROUND

The European bison is an endangered species, and as such it is extremely important to monitor herds for pathogens which can lead to reproductive failure. The aim of the present study was to determine the current prevalence of antibodies to pathogens known to potentially influence reproduction in European bison. Serum samples from 183 bison, originating from different parts of Poland, were tested using commercial ELISA tests for antibodies to Chlamydia spp., Coxiella burnetti, Leptospira interrogans, Neospora caninum and Toxoplasma gondii; the findings were compared between captive and main free-ranging herds, and with regard to the influence of demographic factors such as age and sex. The prevalence of seropositivity was also checked with regard to location and the animal species sharing it.

RESULTS

Chlamydia spp. antibodies were present in 48 out of 130 (36.9%) tested samples. Coxiella burnetii was found in one sample out of 178 (0.58%). N. caninum in 36 out of 172 (20.9%) and T. gondii in 23 out of 172 (13.4%). No sample was positive for leptospirosis. Neither sex nor age appeared to have a significant effect on the occurrence of antibodies to the identified species. The prevalence of Chlamydia spp. in the samples varied significantly according to location; however, similar frequency ranges were observed between free ranging and captive herds. In contrast, antibodies to N. caninum were more common in free-ranging herds than captive herds, with the highest frequency observed in the Bieszczady Mountains.

CONCLUSIONS

Chlamydia spp., N. caninum and T. gondii might have a similar impact on the reproductive potential of European bison as they have on cattle. The high occurrence of antibodies to N. caninum in bison from the Bieszczady Mountains may be associated with the relatively high density of the wolf population in the area.

Antibody responses in European bison (Bison bonasus) naturally infected with Mycobacterium caprae

Mycobacterium caprae, a member of the Mycobacterium tuberculosis complex, infects humans and animals causing lesions and disease like that of Mycobacterium bovis. The aim of this study was to evaluate antibody responses in European Bison (EB, Bison bonasus; a vulnerable species) naturally infected with M. caprae using dual path platform (DPP) BovidTB test and multi-antigen print immunoassay (MAPIA). Study cohorts consisted of naturally M. caprae-infected EB (n = 4), M. caprae-exposed but uninfected (n = 3), EB infected with non-tuberculous mycobacteria or other respiratory pathogens (n = 3), and negative controls (n = 19). M. caprae-infected EB were seropositive by both DPP and MAPIA; 3/4 were seropositive by DPP; and 4/4 were seropositive by MAPIA. One M. caprae-infected animal that developed generalized disease with most advanced gross lesions in the group produced the most robust antibody response. All 25 EB with no culture-confirmed M. caprae infection, including three animals exposed to M. caprae and three other animals infected with non-tuberculous pathogens, were seronegative on both tests. Antibody responses to M. caprae infection included IgM antibodies against MPB70/MPB83 and IgG antibodies to both MPB70/MPB83 and CFP10/ESAT-6. This study demonstrates the potential for use of serological assays in the ante-mortem diagnosis of M. caprae infection in EB.

Biopsy and Tracheobronchial Aspirates as Additional Tools for the Diagnosis of Bovine Tuberculosis in Living European Bison (Bison bonasus)

Simple Summary

In this study, additional methods of collecting material for bovine tuberculosis diagnosis in living European bison were introduced. We showed a potential usage of tracheobronchial aspirates and ultrasound-guided biopsies from lateral retropharyngeal lymph nodes in living animals for diagnostics. We confirmed that the isolation of Mycobacterium caprae in living European bison is possible, as is the respiratory shedding of viable M. caprae in this host. This study is important as tuberculosis is a real threat for European bison which is an endangered species and the improvement of diagnostics can help with better health monitoring and further restitution.

Abstract

The diagnosis of bovine tuberculosis (BTB) in living wildlife remains a complex problem, and one of particular importance in endangered species like European bison (Bison bonasus). To identify infection and avoid the unnecessary culling of such valuable individuals, current best practice requires the collection and culture of material from living animals, as mycobacteria isolation remains the gold standard in BTB diagnosis. However, such isolation is challenging due to the need for the immobilization and collection of appropriate clinical material, and because of the sporadic shedding of mycobacteria. In the present study, we evaluated the potential of sampling for the detection of BTB in a group of seven living European bison suspected of being infected with Mycobacterium caprae. The specimens were collected both as swabs from the nasal and pharyngeal cavities, tracheobronchial aspirates (TBA), ultrasound-guided biopsies from lateral retropharyngeal lymph nodes, and post mortem, from mandibular, retropharyngeal and mediastinal lymph nodes. Clinical samples were tested for mycobacterial species via mycobacteriological culture and PCR. M. caprae was isolated from collected material in two out of four living infected individuals (TBA, biopsy) and mycobacterial DNA was detected in three out of four (TBA, pharyngeal swab) bison. This is the first report of isolation of M. caprae in living European bison. Our findings demonstrate the value of diagnostic tests based on both molecular testing and culture in European bison and confirm the respiratory shedding of viable M. caprae in this host species.

Epidemiological characterization of Mycobacterium caprae strains isolated from wildlife in the Bieszczady Mountains, on the border of Southeast Poland

Background

The majority of animal tuberculosis (TB) cases reported in wildlife in Poland over the past 20 years have concerned the European bison inhabiting the Bieszczady Mountains in Southeast Poland: an area running along the border of Southeast Poland. As no TB cases have been reported in domestic animals in this region since 2005, any occurrence of TB in the free-living animals inhabiting this area might pose a real threat to local livestock and result in the loss of disease-free status. The aim of the study was to describe the occurrence of tuberculosis in the wildlife of the Bieszczady Mountains and determine the microbiological and molecular characteristics of any cultured strains. Lymph node samples were collected for analysis from 274 free-living animals, including European bison, red foxes, badgers, red deer, wild boar and roe deer between 2011 and 2017. Löwenstein–Jensen and Stonebrink media were used for culture. Molecular identification of strains was performed based on hsp65 sequence analysis, the GenoType®MTBC (Hain Lifescience, Germany) test, spoligotyping and MIRU-VNTR analysis.

Results

Mycobacterium caprae was isolated from the lymph nodes of 21 out of 55 wild boar (38.2%; CI 95%: 26.5%, 51.4%) and one roe deer. Since 2014, no new TB cases have been reported in the Bieszczady European bison population.

Conclusions

The identification of TB in wild boar in the Bieszczady is an alarming phenomenon, which requires further investigation. The Bieszczady mountains are a precious, unique area, home to many protected species. However, it is also the only area in Poland where TB cases have been reported in free-living animals. The occurrence of TB in wild boar inhabiting this area might pose a real threat to local livestock and many of the protected species (for example European bison that can share feeding places with wild boar). Given this situation, ongoing monitoring of the prevalence of TB should be conducted, and protective measures should be considered.

Mycobacterium avium: an Emerging Pathogen for Dog Breeds with Hereditary Immunodeficiencies

Purpose of Review

Among the nontuberculous mycobacteria (NTM), Mycobacterium avium complex (MAC) is the leading cause of pulmonary disease in humans. Innate and acquired immunodeficiencies have been associated with an increased host susceptibility to NTM infections. The underlying mechanisms predisposing humans and dogs to MAC infections is being elucidated.

Recent Findings

Although MAC infection is infrequently diagnosed in dogs, a strong breed predisposition particularly for Miniature Schnauzer and Basset Hound dogs is evident. A recessively inherited defect of the adaptor protein CARD9 has recently been documented to be responsible for the increased susceptibility to MAC in the Miniature Schnauzer breed.

Summary

Given the zoonotic potential of a MAC infected dog particularly to immunocompromised human patients, diseased dogs pose a public health risk. While not a reportable disease, treatment of systemic mycobacteriosis is generally not effective and discouraged in dogs. The collaborative efforts by microbiologists, veterinary clinicians, dog breeders, primary care physicians, and infectious disease specialists applying the One Health approach is therefore crucial for the best management and prevention of MAC infection.

Molecular Characterisation of the Mycobacterium Bovis Causing Bovine Tuberculosis Outbreaks in Poland

Introduction

Since 2009, Poland has been recognised as a country officially free of bovine tuberculosis (bTB), although in each year of the last five there were from 8 to 18 outbreaks of the disease. In 2008–2016, the largest number of cattle infected with bovine mycobacteria were eliminated in the Masovian Province (the central region of Poland) and the largest number of outbreaks of this zoonosis were recorded in this area. The close proximity of farms where bTB was found led to the suspicion that tuberculosis could have been transmitted between the affected herds. The aim of the study was the molecular characterisation of the pertinent M. bovis/caprae strains and determination of the epidemiological relationship of various bTB outbreaks.

Material and Methods

The material for microbiological tests came from 119 cattle (Bos taurus) from nine herds located in five provinces, neighbouring the Masovian Province.

Results

Laboratory tests of tissue material gave results confirming tuberculosis in 54 (45%) animals. All strains belonged to the Mycobacterium bovis species. A two-step analysis of genetic affinity allowed 50 strains to be identified as phylogenetically closely related and separated between three genetic clusters consisting of 2 to 27 strains.

Conclusion

Based on the results of genotyping, bTB outbreaks were found in three herds, and three transmission chains were identified among these herds.

Shedding of Mycobacterium caprae by wild red deer (Cervus elaphus) in the Bavarian alpine regions, Germany

The number of natural infections with Mycobacterium caprae in wildlife and in cattle in the Bavarian and Austrian alpine regions has increased over the last decade. Red deer (Cervus elaphus) have been recognized as maintenance reservoir; however, the transmission routes of M. caprae among and from naturally infected red deer are unknown. The unexpected high prevalence in some hot spot regions might suggest an effective indirect transmission of infection. Therefore, this study was undertaken to diagnose the occurrence of M. caprae in faeces and secretions of red deer in their natural habitat. A total of 2,806 red deer hunted in this region during 2014-2016 were included in this study. After pathological examination, organs (lymph nodes, lung, heart), excretions and secretions (faeces, urine, saliva and tonsil swabs) were further investigated by qPCR specific for Mycobacterium tuberculosis complex (MTC), M. bovis and M. caprae. Samples tested positive by qPCR were processed for culturing of mycobacteria. In total, 55 (2.0%) animals were confirmed positive for M. caprae by pathological examination, PCR and culturing of the affected organ material. With the exception of one sample, all of the secretion and excretion samples were negative for mycobacteria of the Mycobacterium tuberculosis complex (MTC). From one red deer, M. caprae could be isolated from the heart sac as well as from the faeces. Whole-genome sequencing confirmed that both strains were clonally related. This is the first confirmation that M. caprae can be shed with the faeces of a naturally infected red deer. However, further studies focusing on a higher number of infected animals, sample standardization and coordinated multiple sampling are necessary to improve the understanding of transmission routes under natural conditions.

Seroprevalence and risk factors for selected respiratory and reproductive tract pathogen exposure in European bison (Bison bonasus) in Poland

After the complete extinction from the wild of European bison (Bison bonasus) at the beginning of the twentieth century, the worldwide species population was restored to approximately 5500 individuals, with the species however remaining endangered. Despite numerous studies on the ecology and genetics of European bison, the threats of infectious diseases have been largely unexamined. The aim of this study was to screen the exposure of the world's largest population of European bison to the pathogens, which may influence the condition and development of the endangered species. A total of 240 free-ranging and captive European bison from eight main Polish populations sampled were tested for the presence of specific antibodies against ten different viruses, bacteria or protozoan. The samples were collected from chemically immobilized, selectively culled or found dead animals. Based on serology, the exposure to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BoHV-1), Mycoplasma and Brucella spp. was determined as rather accidental. Using gamma-interferon assay followed by Mycobacterium tuberculosis subs. caprae detection in tissues, diagnosis of bovine tuberculosis was made for 6 out of 78 (7.7%) bison from one captive herd. The highest seroprevalence was found for bovine adenovirus type 3 (BAdV-3) -60.2% and bovine parainfluenza type 3 (PIV-3) -34.0%, while the antibodies against bovine respiratory syncytial virus (BRSV), Toxoplasma gondii and Leptospira spp. were found in 10.4%, 10.4% and 8.7% of samples, respectively. In the multivariable statistical analysis using generalized linear mixed models (GLMMS), the risk factors for PIV-3 seropositivity included population type (free-living/captive), age and health status (apparently healthy/eliminated due to the poor condition). Higher risk of BAdV-3 seropositive result was observed in free-living female European bison. The high BAdV-3 and PIV-3 seroprevalences may suggest involvement of these pathogens in the most frequently observed respiratory disorders in European bison. Moreover, this is the first study demonstrating BAdV-3 exposure in the species.