Samaneh Saedi - Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
kiarash ghazvini - Department of Microbiology and Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Masoud Youssefi - Department of Microbiology and Virology, Mashhad University of Medical Sciences, Mashhad, Iran.
Hadi Safdar - Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
saman soleimanpour - Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Parviz Afrough - Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Amir Azimian - Microbiology and Virology Research Centre, department of Bojnord University of Medical Sciences, Bojnord, Iran
hamid solgi - Departmant of Mycobacteriology & Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran. Microbiology Research Center (MRC) Pasteur Institute of Iran.
Masoud Keikha - Department of Microbiology and Virology, Faculty of Medicine, Iranshahr University of Medical Sciences, Iranshahr, Iran

AbstractBackground: Mycobacterium tuberculosis is still one of the most dangerous human pathogens. Identification of the relationships between different clinical strains has remained a high priority for epidemiology research. Methods: In this study, we used MLSA (Multilocus sequence analysis) to generate a highly robust phylogeny of M. tuberculosis. MLSA, based on single nucleotide polymorphism (SNP) was performed on five genes fragments from the Rpsl (۳۰۲ bp), MprA (۵۵۹ bp), LipR (۳۲۲ bp), KatG (۴۸۸ bp) and Fgd۱ (۲۶۶ bp), in order to identify polymorphic nucleotide sites, and the discriminatory power of each locus for all genes was measured with Hunter‐Gaston Index (HGI). Results: In this study, a sequence type (ST) number was assigned to each unique allelic profile, and ۹ sequence types were identified from ۲۰ strains, these imply that there is a high diversity of strains in this area. Conclusion: Our results showed that the presence of high genetic diversity among clinical isolates of M. tuberculosis in Northeast of Iran. There is no evidence for recent transmission. Keywords: Mycobacterium tuberculosis, Multi-locus sequence analysis; Molecular epidemiology; Tuberculosis; KatG; Rpsl۱. IntroductionMycobacterium tuberculosis (M. tuberculosis), the causative agents of tuberculosis (TB), is one of the most successful human pathogens, infecting nearly one-third of the people all around the world,causing over ۹ million new cases and ۱.۷ million deaths each year [۱-۲]. Identification of the relationships between different clinical strains of M. tuberculosis has great significance to the public health [۳].

Mycobacterium tuberculosis, Multi-locus sequence analysis, Molecular epidemiology, Tuberculosis, KatG, Rpsl