The isolation of an atypical Mycobacterium from three wood pigeons with tuberculosis-like lesions
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Abstract:
Cultural and biological tests were carried out on the livers and spleens of three wood pigeons. Acid-fast organisms were observed in histological sections and smears taken from tuberculosis-like lesions in the organs. Biological tests revealed that all the isolates sensitised the guinea pig to avian tuberculin. One was pathogenic for chickens while the remaining two were non-pathogenic. All were non-pathogenic for rabbits and domestic pigeons. The organisms could not be cultured on conventional media for Mycobacterium tuberculosis or media containing mycobactin. However they were readily maintained on 7H11 media. These results indicate a separate species of mycobacterium related to M avium.
Insights
Researchers identified a novel mycobacterium species in wood pigeons with tuberculosis-like lesions. This organism is related to Mycobacterium avium, suggesting a new pathogen affecting avian species.
Area of Science:
- Veterinary Microbiology
- Avian Pathology
- Mycobacteriology
Background:
- Tuberculosis-like lesions were observed in the livers and spleens of three wood pigeons.
- Acid-fast organisms were identified in histological sections and smears from these lesions.
Purpose of the Study:
- To characterize the acid-fast organisms isolated from wood pigeon lesions.
- To determine the pathogenicity and cultural characteristics of these isolates.
- To ascertain the taxonomic relationship of the isolates to known mycobacteria.
Main Methods:
- Histological examination and smear preparation of affected organs.
- Biological tests in guinea pigs, chickens, rabbits, and domestic pigeons.
- Culturing attempts on various media, including conventional Mycobacterium tuberculosis media, mycobactin-containing media, and 7H11 media.
Main Results:
- All isolates sensitized guinea pigs to avian tuberculin.
- One isolate was pathogenic for chickens; the other two were not.
- All isolates were non-pathogenic for rabbits and domestic pigeons.
- Organisms failed to grow on conventional media for Mycobacterium tuberculosis or mycobactin-containing media but grew on 7H11 media.
Conclusions:
- The isolated organisms represent a distinct species of mycobacterium.
- This novel species is closely related to Mycobacterium avium.
- The findings contribute to understanding mycobacterial diversity and avian diseases.