Cultivable mycobacteria isolated from organs of armadillos uninoculated and inoculated with Mycobacterium leprae.

Mycobacteria were cultivated from 16 out of 32 samples of tissues from armadillos inoculated with Mycobacterium leprae. Three out of 7 samples from non-inoculated armadillos held in captivity were also positive for cultivable mycobacteria. Some isolated strains belonged to the M. avium-intracellulare-scrofulaceum complex, while others were identified as M. gordonae and M. terrae. Unclassified mycobacteria were isolated from M. leprae-inoculated armadillos only. Taxonomic studies confirmed that these new armadillo-derived mycobacteria (ADM) are different from all presently known species of mycobacteria, including M. leprae. The same new species were isolated from different armadillo colonies and were never found in non-inoculated animals. Different factors influence the isolation of these ADM in primary culture. Analysis of some specific markers of these ADM has been suggested in order to quantitatively determine the proportion of these ADM to M. leprae in armadillo tissues. No mycobacteria were cultivated from Nude mouse footpads infected with M. leprae.