Use of DNA fingerprinting in identifying the source case of tubercolosis in East Azarbaijan province of Iran

Abstract

In recent years inspite of medical advancement, tuberculosis remains as a worldwide health problem. Identifying the source of transmission of infection is necessary for decreasing of tuberculosis (TB). Determining the variety of TB strains by DNA fingerprinting help to this work. The aim of this study was to determine tuberculosis transmission dynamics in East Azarbaijan province by focusing on prevention of its transmission. In an attempt to identify new epidemic and transmission, Restriction Fragment Length Polymorphism (RFLP) typing was performed on 119 culture-positive specimens in East Azarbaijan. Using IS6110 as a probe, Mycobacterium tuberculosis strains were assigned to clusters based on identical DNA fingerprints. Twelve clusters were found among total of 38 strains. The clusters included 26 patients that infected by 12 another's. Ninthy-three distinct IS6110 patterns were revealed. Eighty-one of these patterns were unique and 12 were shared by 2 to 8 strains. The minimum estimate for transmission in East Azarbaijan province was 22%. RFLP typing is a useful instrument to more knowledge about transmission and the occurrence of micro-epidemics and international source tracing, as we found a Nakhichevanees patient referred to tuberculosis center of province could be a source for transmission of tuberculosis.