Microbiological and molecular monitoring for bovine tuberculosis in the Polish population of European bison (Bison bonasus)

INTRODUCTION AND OBJECTIVE

In recent years, bovine tuberculosis (BTB) has become one of the major health hazards facing the European bison (EB, Bison bonasus), a vulnerable species that requires active protection, including regular and effective health monitoring. Monitoring of zoonotic disease in wildlife is also an important part of public health protection. The aim of the study was to determine whether BTB still influences the EB population in Poland.

MATERIAL AND METHODS

During 2017-2019, mandibular, retropharyngeal and mediastinal lymph nodes were collected from 90 EB during post-mortem examination, and then cultivated on Lowenstein-Jensen and Stonebrink media. Isolated strains were subjected to molecular analysis to determine the species, spoligotype and MIRU-VNTR pattern.

RESULTS

Lesions were found in lymph nodes originating from eight EB (8.89%). Positive microbiological cultures for mycobacteria were obtained in samples from six (6.67%) EB. The isolated strains were identified as Mycobacterium caprae (material from four EB) and atypical mycobacteria (material from two EB). For M. caprae strains spoligotype M. bovis 4_CA 1600 was identified and the MIRU-VNTR pattern was identified as 345751355413232.

CONCLUSIONS

It is recommended that this potentially dangerous disease should be monitored in EB via a comprehensive strategy based on a combination of microbiological and molecular methods. Such monitoring will protect the health of both animals and humans.

Large lungworms (Nematoda: Dictyocaulidae) recovered from the European bison may represent a new nematode subspecies

Although the Dictyocaulus lungworm, the agent of dictyocaulosis, is one of parasitological threats to European bison, its systematic position remains unclear. The aim of the present study was to evaluate the morphological features of the lungworm and the pathological lesions it induces, and to analyse mitochondrial (mt) genetic markers for systematic and molecular epidemiological studies. The morphological findings indicate that Dictyocaulus lungworms of European bison can be distinguished from those of cattle on the basis of differences in buccal capsule wall length, total body length, and spicules length in males, all of which were significantly longer in those of European bison. Nucleotide diversity calculated from pairwise sequence alignments of partial cytochrome c oxidase subunit 1 (cox1), cytochrome B (cytB) and NADH dehydrogenase subunit 5 (nad5) of specimens from cattle and European bison varied from 1.7% for nad5, 2.1% for cytB, to 3.7% for cox1 gene. Thus, among the lungworms of European bison and cattle, nad5 and cytB were the most conserved proteins, whereas cox1 was the most diverse. The mt cytB marker gene may be a suitable candidate for distinguishing between the two genotypes, as nad5 demonstrated the greatest within-genus sequence variation. The lung tissue of infected European bison manifests signs of verminous pneumonia characterized by interstitial pneumonia, bronchitis and bronchiolitis. Therefore, it appears that European bison and cattle are infected with slightly diverged, morphologically-different, genotypes of D. viviparus, indicating they belong to two separate worm populations. We propose, therefore, that the lungworm of European bison should be classified as D. viviparus subsp. bisontis.

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European bison harbour a unique morphotype and genotype of Dictyocaulus viviparus.

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Mt cytB is an efficient genetic marker for studying large lungworms in bovids.

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European bison lungworm can be classified as D. viviparus subsp. bisontis.

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Pathologies induced by a newly described nematode subspecies mirrored those of lungworm in cattle.