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

Determination of hematological and biochemical values blood parameters for European bison (Bison bonasus)

Hematological and biochemical blood parameters are important tools for evaluating animals' health. They might be crucial in assessing the health of entire populations of wild animals, such as European bison (Bison bonasus). The aim of this study was to establish hematological and biochemical values for healthy European bison and to determine whether there were significant relations with age and sex. Blood samples were collected from 79 animals and tested according to generally accepted standards and the results were subjected to statistical analysis. Most of the age and gender-related correlations found in our study were predictable based on previous reports. Due to bone growth, juvenile animals have typically higher ALP and P concentrations relative to adults. Several age-related dependencies were surprising, like higher Na concentration in younger European bison. Determination of hematological and biochemical blood parameters of healthy European bison may significantly contribute to the further restitution of this endangered species.

Antibodies against the Mycobacterium tuberculosis complex and Brucella spp. in captive and free-living European bison (Bison bonasus) in Poland

BACKGROUND

The European bison (Bison bonasus), a symbol of Polish nature, is a protected species that requires active health monitoring. However, conservation efforts are made difficult by the zoonotic diseases such as brucellosis and tuberculosis.

OBJECTIVE

The aim of this study was to screen the Polish European bison population for exposure to the Mycobacterium tuberculosis complex (MTC) and Brucella spp.

METHODS

A total of 323 free-living and captive European bison from 13 localities were tested serologically for antibodies against the M. bovis P22 multi-protein complex (in-house ELISA) and against Brucella spp. (commercial ELISA).

RESULTS

Antibodies against the MTC (P22) were detected in 7% (22/323) of the tested European bison. Anti-MTC antibody positivity was not significantly different by sex, age, and captive/free range status. Anti-MTC antibodies were found in six of 13 populations sampled, always in populations with larger sample sizes including the four free-living ones. Antibodies against Brucella spp. were detected in 36% (116/323) of the tested bison. While Brucella spp. antibody prevalence was not different by sex, it was significantly different by age (lower in adults) and captive/free-living status. Brucella spp. seroprevalence decreased with sample size and seropositive bison were found in 12 of 13 sampling populations.

CONCLUSIONS

Our findings identify potential emerging threats to the European bison population and confirm the first serological response to P22 in European bison. As Poland is currently officially free of brucellosis and bovine tuberculosis, our results require careful interpretation. Further studies are needed to establish the presence of cross-reactions with atypical mycobacteria in the case of MTC and other bacteria (e.g. Yersinia enterocolitica O:9) in the case of Brucella spp.

Ten Years of Animal Tuberculosis Monitoring in Free-Living European Bison (Bison bonasus) in Poland

In the period 1996–2012, two outbreaks of animal tuberculosis were noted in the population of free-living European bison (Bison bonasus caucasicus) in the Bieszczady Mountains, Southern Poland. As the European bison is an endangered species and particularly susceptible to tuberculosis, not to mention a national icon, the decision was made to test all deceased bison for TB in Poland. The screened bison were obtained by elimination due to poor health or natural death. A total of 159 European bison have been examined over the last 10 years. The individuals came from four regions of Poland (Białowieża Forest, Bieszczady Mountains, Borecka Forest, Knyszyńska Forest), not only from the area where tuberculosis is still endemic. Mycobacterium bovis and Mycobacterium avium spp. hominisuis were identified in two different herds. The isolation of M. bovis from European bison was the first case described in Poland. So far, the only causative agent of tuberculosis identified in European bison in Poland, both in the wild and in captive herds, was Mycobacterium caprae. The isolated M. bovis spoligotype has not previously been registered in international spoligotype databases so far. The obtained results highlight the need to monitor TB in European bison in Poland.

Comorbidities and concentration of trace elements in livers of European bison from Bieszczady Mountains (Poland)

European bison is a species for which health monitoring is essential in conservation activities. So far, little research has been carried out on the concentration of elements in this species. Most previous studies did not associate the concentration of elements with susceptibility to diseases. In this study we investigate the relationship between comorbidities in European bison and concentrations of a wide spectrum of elements in the liver. Samples were collected during the monitoring of the European bison population in Bieszczady (southeast Poland) over the 2020-2022 period. Each individual was also visually inspected by a veterinarian in the field for the presence of lesions as a part of a post-mortem examination. The animals were divided into 3 groups: group A-one type of clinical sign; group B-two types of clinical signs; group C-three or more types of clinical signs. The ICP-OES method was applied to assess the concentration of 40 elements in livers. Discriminant analysis showed clear differences between the mineral status of individuals in the groups with one, two, and at least three types of clinical signs. Detailed analysis of selected elements showed that, in the case of eight elements, there was a relationship with age, sex, or comorbidities. Cu, Se, and Zn showed significant differences in relation to comorbidities, but only Cu concentration was lower when the frequency of lesions was higher. We concluded that in research on the mineral status of the population, apart from the availability of trace elements in the environment, the health condition of the studied individuals should also be considered. However, inferring the mineral status of the population on the basis of randomly obtained samples from dead individuals may give an incomplete view of the population, especially in the case of species susceptible to diseases, such as European bison.

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.

Review on Bovine Tuberculosis: An Emerging Disease Associated with Multidrug-Resistant Mycobacterium Species

Bovine tuberculosis is a serious infectious disease affecting a wide range of domesticated and wild animals, representing a worldwide economic and public health burden. The disease is caused by Mycobacteriumbovis and infrequently by other pathogenic mycobacteria. The problem of bovine tuberculosis is complicated when the infection is associated with multidrug and extensively drug resistant M. bovis. Many techniques are used for early diagnosis of bovine tuberculosis, either being antemortem or postmortem, each with its diagnostic merits as well as limitations. Antemortem techniques depend either on cellular or on humoral immune responses, while postmortem diagnosis depends on adequate visual inspection, palpation, and subsequent diagnostic procedures such as bacterial isolation, characteristic histopathology, and PCR to reach the final diagnosis. Recently, sequencing and bioinformatics tools have gained increasing importance for the diagnosis of bovine tuberculosis, including, but not limited to typing, detection of mutations, phylogenetic analysis, molecular epidemiology, and interactions occurring within the causative mycobacteria. Consequently, the current review includes consideration of bovine tuberculosis as a disease, conventional and recent diagnostic methods, and the emergence of MDR-Mycobacterium species.