مقايسه و شناسايي ميزان آلودگي مايكوباكتريوم بويس و مايكوباكتريوم توبركلوزيس با روش هاي هيستوپاتولوژي، كشت و PCR در عقده هاي لنفاوي گاوهاي كشتارشده در كشتارگاههاي اطراف استان تهران

Comparison of histopathology, culture and multiplex PCR in order to diagnosis of mycobacterium bovis and mycobacterium tuberculosis in slaughtered cowʹs lymph nodes of slaughterhouses around Tehran province

Tuberculosis is the considered as one of the most important and dangerous zoonosis and will cause irreparable economic losses to dairy industry each year. In order to spread prevention, early diagnosis and culling infected animals is necessary. Considering the prevalence of mycobacterium in the slaughterhouses is unknown so that the prevalence evaluation of them in slaughterhouses is important. In this study 5000 slaughtered carcasses during a year were evaluated and from these, 250 samples had obvious detectable Tuberclosis lesions in their lymph nodes. Lymph nodes for confirmation of tuberculosis were referred to laboratory. Initially tissue samples were prepared and microscopic observation was done and then samples were cultured and finally multiplex PCR was performed. From 250 samples that had evaluated with histopathologic method, 230 were suspected to tuberculosis. These suspected samples were cultured in specific media and confirmed by Niacin test. The results were 137 samples infected with mycobacterium bovis, 10 samples infected by mycobacterium tuberculosis. In examining multiplex PCR method using specific primers, from 147 positive samples obtained from culture, 127 samples infected by mycobacterium bovis , 15 samples infected by mycobacterium tuberculosis and 5 samples were infected with both agents. By comparing the results of histopathology, multiplex PCR and culture, multiplex PCR has higher sensitivity than other methods in order to diagnosis of mycobacterium species.