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Histopathological classification of systemic Mycobacterium avium complex infections in slaughtered domestic pigs
Kenji Hibiya1, Yuko Kasumi, Isamu Sugawara
1Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases, Faculty of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903 0215, Japan. k068736@eve.u-ryukyu.ac.jp
Abstract:
The aim of this study was to classify the histopathological features of pigs infected with Mycobacterium avium complex (MAC). We used slaughtered pig organs systemically infected with MAC. The results showed granulomatous lesions which were observed predominantly in the digestive organs and regional lymph nodes rather than respiratory organs. The histological picture showed a wide range of granulomatous stages from exudative to fibrotic reactions to the MAC infection. Eosinophils and giant cells were characteristically observed in the exudative reactions. The histopathological type in primary focus tended to be maintained in the respective organs. Most strains with the same genotype showed pathogenicity for guinea pigs irrespective of the type of granuloma. Although these findings suggest that different stages of a granulomatous lesion originating from the same causative agent might influence histological patterns, other possibilities such as the hereditary background of the host, or the effects of viral infections should be considered.
Insights
This study classified pig histopathology from Mycobacterium avium complex (MAC) infection, finding lesions mainly in digestive organs. Lesion stages varied, but MAC strains showed consistent pathogenicity regardless of granuloma type.
Area of Science:
- Veterinary Pathology
- Microbiology
- Immunology
Background:
- Mycobacterium avium complex (MAC) infections pose a significant challenge in swine health.
- Understanding the histopathological manifestations of MAC in pigs is crucial for disease management.
Purpose of the Study:
- To classify the histopathological features of pigs systemically infected with Mycobacterium avium complex (MAC).
- To correlate histopathological findings with MAC strain genotypes and pathogenicity.
Main Methods:
- Examination of slaughtered pig organs systemically infected with MAC.
- Histopathological analysis of granulomatous lesions, noting stages and cellular components.
- Assessment of MAC strain pathogenicity in guinea pigs.
Main Results:
- Granulomatous lesions were predominantly observed in digestive organs and regional lymph nodes, less so in respiratory organs.
- Histological pictures revealed a spectrum of granulomatous reactions, from exudative to fibrotic, with eosinophils and giant cells in exudative stages.
- MAC strains with the same genotype exhibited pathogenicity in guinea pigs, irrespective of the observed granuloma type.
Conclusions:
- Histopathological patterns in MAC-infected pigs vary with lesion stage and host factors.
- While MAC genotype influences pathogenicity, host hereditary background and concurrent viral infections may also affect lesion development.
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