Zeaur Rahim
International Centre for Diarrheal Disease Research, Bangladesh
Title: Mycobacterium orygis: Emerging causative agent of tuberculosis in cattle in Bangladesh
Biography
Biography: Zeaur Rahim
Abstract
Bangladesh is one of the tuberculosis (TB) endemic countries of the world. National TB control program has proper attention on
human TB, but TB in cattle is neglected. In this study, vital organs of the dead cows were analyzed after postmortem to isolate
and identify Mycobacterium from the vital organs of the dead cows, perform drug susceptibility testing and genotyping of isolates.
After post-mortem, part of the tissue samples from vital organs was processed for histopathological examination. For culture, tissue
homogenate samples were inoculated on Lowenstein-Jensen slants. Characteristic colonies were confirmed Mycobacterium by acidfast
staining and colony morphology. Anti-TB drug sensitivity testing was performed following proportion method. For molecular
characterization, DNA was extracted from the culture of Mycobacterium for RD analysis, single nucleotide polymorphism for genes like;
gyrB, mmlp6, TbD1 and PPE55 genes. Genotyping was performed by standard spoligo and VNTR-MIRU typing. Histopathological
examination, demonstrated prominent granuloma, caseous necrosis and calcification as proof of TB. Mycobacterium grew from the
vital organs of 18 out 21 dead cattle. AFB staining, sensitivity to PNB indicated that the strains belong to M. tuberculosis complex.
Molecular characterization indicated that these strains belong to new species M. orygis. Isolated strains were sensitive to all first line
anti-TB drugs. M. orygis is an emerging species of Mycobacterium causing cattle TB. Detailed epidemiological study of M. orygis
needs to be conducted to control this disease. Sensitivity to all first line anti-TB drugs indicated that human infection with this TBbacillus
could be successfully treated with anti-TB drugs.