RESUMO
Mycobacterium tuberculosis complex is consisted of homogenous organisms. They are slowly growing mycobacteria and their isolation and identification are difficult and time consuming. Differentiation of Mycobacterium bovis, causative mammalian tuberculosis, from other members of Mycobacterium tuberculosis complex is very important in epidemiology and control of disease in humans and animals. The aim of this study was to evaluate a molecular method to differentiate Mycobacteriom bovis from Mycobacterium tuberculosis. DNA human isolates of Mycobacterium tuberculosis [n=6] and Mycobacterium bovis isolates [50] were extracted and used as template in PCR. A 548bp fragment of oxyR pseudogene was amplified and digested with Alul endo nuclease. The nucleotide 285 could be adenine [M. bovis] or guanine [M. tuberculosis]. Such variation produces different restriction site for Alul. There were three incisive fragments in all Mycobacterium bovis and Mycobacterium bovis BCG strains and one incisive fragment in other members of Mycobacterium tuberculosis complex. PCR-RFLP method on 548bp fragment of oxyR gene is a rapid and accurate method to differentiate Mycobacterium bovis and Mycobacterium bovis BCG from other members of Mycobacterium tuberculosis complex