A histopathological study in road-killed European badgers (Meles meles) from the English midlands with isolation of novel non-tuberculous atypical mycobacteria

Corbetta, D; Grau-Roma, L; Rees, C; Swift, BMC; O'Cathail, C; Barron, ES; Verin, R; Morey-Matamalas, A; Sorley, M; Bennett, M

Abstract

European badgers (Meles meles) play an important role in the epidemiology of bovine tuberculosis (caused by Mycobacterium bovis) in England, but little is known about the prevalence of atypical mycobacteriosis. Badgers are also known to be infected by other infectious agents, and the relationship between mycobacteriosis and concomitant infections needs further investigation. Overall, 88 badger carcasses from the Midlands of England collected between July 2016-August 2017 were selected for histopathological examination based on the degree of autolysis (mild), mycobacterial culture results and a balanced sex ratio. Mycobacteria were cultured from 44 badgers, of which 31 were mycobacteria belonging to the M. tuberculosis complex (MTBC) (based on IS6110 PCR and Hsp64 and/or rRNA PCR and sequencing) and 13 were non-tuberculous atypical mycobacteria (NTM). Mycobacteria were not cultured from the remaining 44 animals. Histologically, the most common findings were silica-laden macrophages (85%), granulomas (53%), sarcocystosis (47%), nephritis (31%), portal/periportal hepatitis (26%), ulcerative dermatitis (18%). Culturable mycobacteriosis was associated with higher prevalence of granulomas (p < 0.001) and lower prevalence of hepatitis (p = 0.003). NTM (M. nonchromogenicum, M. avium complex, M. hassiacum, M. malmoense, M. vaccae.) infections were associated with granulomatous pneumonia, and M. malmoense was associated with pyogranulomatous and ulcerative dermatitis. In conclusion, this study describes, for the first time, histological lesions associated with NTM in badgers, the histomorphology of which was similar to those caused by MTBC. In addition, the negative relationship between mycobacteriosis and periportal hepatitis may indicate a complex relationship between mycobacteriosis and other diseases, as previously observed with tuberculosis.

Citation

Corbetta, D., Grau-Roma, L., Rees, C., Swift, B., O'Cathail, C., Barron, E., Verin, R., Morey-Matamalas, A., Sorley, M., & Bennett, M. (2024). A histopathological study in road-killed European badgers (Meles meles) from the English midlands with isolation of novel non-tuberculous atypical mycobacteria. European Journal of Wildlife Research, 70(6), https://doi.org/10.1007/s10344-024-01866-4

• Journal Article Type: Article
• Acceptance Date: Oct 17, 2024
• Online Publication Date: Oct 28, 2024
• Publication Date: 2024
• Deposit Date: Dec 2, 2024
• Publicly Available Date: Dec 2, 2024
• Journal: European Journal of Wildlife Research
• Print ISSN: 1612-4642
• Electronic ISSN: 1439-0574
• Publisher: Bioscientifica
• Peer Reviewed: Peer Reviewed
• Volume: 70
• Issue: 6
• DOI: https://doi.org/10.1007/s10344-024-01866-4
• Keywords: European badger(Meles meles); Mycobacterium malmoense; Mycobacterium nonchromogenicum; Mycobacterium avium; Mycobacterium vaccae; Nontuberculous atypical mycobacteria; PULMONARY INFECTION; BOVIS INFECTION; SOUTH-WEST; TUBERCULOSIS; DISEASE; BCG; EFFICACY; PATIENT; VIRUS