[Comparative study of mycobactin-dependent strains of mycobacteria isolated from the wood-pigeon with Mycobacterium avium and M. paratuberculosis: study of biological and antigenic characteristics].
In this investigation three mycobacterial strains isolated in our laboratory from wood-pigeons were compared with one strain isolated by Matthews and another by Jorgensen from, respectively, a wood-pigeon and a roe-deer. The strains were also compared with various strains of Mycobacterium avium and M. paratuberculosis. The strains isolated from the wood-pigeons formed a relatively homogeneous group, which could be distinguished from M. avium and M. paratuberculosis. It was interesting to verify that most of the cultural and biochemical properties of the wood-pigeon mycobacteria were similar to those of M. paratuberculosis. The strains formed rough colonies and grew slowly in special mediums containing M. phlei extracts or mycobactin. However, one must recall that mycobactin dependence was also reported by Matthews for some strains of M. avium. The tween hydrolysis test (10 days), negative for M. avium, was positive for both the wood-pigeon mycobacteria and M. paratuberculosis. The trehalase test, which appears to be regularly positive for M. avium, was also positive for the wood-pigeon mycobacteria and M. paratuberculosis. In respect to drug susceptibility, no significant differences were observed. The organisms were resistant to most drugs studied, but were also resistant to cycloserine, in contrast to most M. avium strains. On the other hand, the organisms were not distinguished using sensitins, prepared from wood-pigeon mycobacteria and M. paratuberculosis using specifically sensitized guinea-pigs. However, the wood-pigeon mycobacteria could be clearly differentiated from M. paratuberculosis and M. avium using serology methods. Indeed, the wood-pigeon mycobacteria did not agglutinate in the presence of any of the sera defining the M. avium-intracellulare serovars (serovars 1 to 28); and by immunodiffusion in agar the wood-pigeon mycobacteria antigens formed two precipitation lines which were absent from M. paratuberculosis. Judging from our findings, the wood-pigeon mycobacteria are more closely related to M. paratuberculosis than to M. avium. It appears that biochemical and antigenic properties are not sufficient to completely differentiate these bacteria. Further studies are needed, and we plan to investigate in the near future their pathogenicity for rabbits, chicken and calves.
D000818:Animals; D000942:Antigens, Bacterial; D010856:Columbidae / Q000382:microbiology*; D003470:Culture Media; D005779:Immunodiffusion; D009161:Mycobacterium / Q000187:drug effects / Q000254:growth & development* / Q000276:immunology; D009162:Mycobacterium avium; D010080:Oxazoles / Q000494:pharmacology; D010283:Paratuberculosis / Q000382:microbiology
D000942:Antigens, Bacterial; D003470:Culture Media; D010080:Oxazoles; C018608:mycobactins
Etude comparative de souches de mycobactéries mycobactine-dépendantes, isolées de pigeon ramier, avec Mycobacterium avium et M. paratuberculosis: étude des caractères biologiques et antigéniques.