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Mycobacterium microti Infections in Free-Ranging Red Deer (Cervus elaphus)
Abstract:
Infections with Mycobacterium microti, a member of the M. tuberculosis complex, have been increasingly reported in humans and in domestic and free-ranging wild animals. At postmortem examination, infected animals may display histopathologic lesions indistinguishable from those caused by M. bovis or M. caprae, potentially leading to misidentification of bovine tuberculosis. We report 3 cases of M. microti infections in free-ranging red deer (Cervus elaphus) from western Austria and southern Germany. One diseased animal displayed severe pyogranulomatous pleuropneumonia and multifocal granulomas on the surface of the pericardium. Two other animals showed alterations of the lungs and associated lymph nodes compatible with parasitic infestation. Results of the phylogenetic analysis including multiple animal strains from the study area showed independent infection events, but no host-adapted genotype. Personnel involved in bovine tuberculosis-monitoring programs should be aware of the fastidious nature of M. microti, its pathogenicity in wildlife, and zoonotic potential.
Insights
Mycobacterium microti infections are rising in wildlife and humans, potentially misdiagnosed as bovine tuberculosis. Awareness is crucial for monitoring programs due to its pathogenicity and zoonotic risks.
Area of Science:
- Veterinary Microbiology
- Wildlife Pathology
- Zoonotic Diseases
Background:
- Mycobacterium microti, part of the M. tuberculosis complex, shows increasing prevalence in humans and animals.
- Lesions from M. microti infections can mimic bovine tuberculosis, complicating diagnosis.
- Red deer are susceptible to M. microti, posing challenges for wildlife health surveillance.
Purpose of the Study:
- To report cases of M. microti infection in red deer.
- To investigate the phylogenetic relationships of M. microti strains in wildlife.
- To highlight diagnostic and surveillance implications for M. microti.
Main Methods:
- Postmortem examination of infected red deer.
- Histopathologic analysis of tissue samples.
- Phylogenetic analysis of M. microti isolates.
Main Results:
- Three cases of M. microti infection identified in red deer from Austria and Germany.
- Diverse clinical presentations observed, including severe pleuropneumonia and lung alterations.
- Phylogenetic analysis indicated independent infection events without host-specific genotypes.
Conclusions:
- M. microti poses a significant diagnostic challenge in wildlife, potentially being misidentified.
- Wildlife health and veterinary personnel must recognize M. microti's pathogenicity and zoonotic potential.
- Enhanced awareness and diagnostic capabilities are needed for M. microti surveillance programs.
