Isolation and identification of multiple drug resistant nontuberculous mycobacteria from organs of cattle produced typical granuloma lesions

- Nontuberculosis mycobacteria could form typical tuberculous granuloma in the lungs, livers and hilar lymph nodes of cattle.
- M. conceptionense was isolated and identified from cattle for the first time.
- Isolates of NTM from cattle were zoonotic and showed multiple drug resistance to routine anti-TB drugs.

Nontuberculosis mycobacteria are widespread in the environment and some are zoonotic. 320 tissue samples with visible lesions were obtained from dairy cows and examined by histopathology. Eleven samples showed typical granulomatous lesions and a total of 8 strains were cultured. Three genes (16S rRNA, hsp65 and rpoB) were sequenced for species identification. All mycobacterial isolates were tested for rifampicin, isoniazid, ethambutol, streptomycin, capreomycin, kanamycin, para-aminosalicylic acid susceptibility. Six strains were identified as M. fortuitum, 1 was M. avium, 1 was M. conceptionense, isolated from cattle for the first time. Seven of the 8 isolated strains showed multiple drug resistance.