Genetic Diversity of Mycobacterium tuberclusis Strains Analysed by Pulsed Field Gel Electrophoresis in Iran

Background & Objectives: In this research about hundered isolates of Mycobacterium tuberclosis strain that were gatherd in Mycobacteriology Department of Pasteur Institude in 2011 -2012 were studied by comparison of larg restriction fragment pattern (LFR) drived from XbaI endonuclease and Pulesd-Field Gel Electrophoresis apparatus to show recent DNA polymorphisms in this isolates. Methods: Isolates were inactived in 80°c for 20 minutes.150 µl of bacterial suspension with 150 µl of melted incert agarose and 10 µl lysozyme were purred in special plags molds. After solidification the plags were lysed with TE buffer containing 10 mg/ml lysozyme and incubated at 37°C for 16 hours .After washing in several stages we used a ESP buffer. Plags remain in this solution for 48 hours at 55°C. Then it washed and digested with XbaI endonuclease. Finally the digested DNA were electrophoresed on 1% agarose on CHEF-DR III apparatus. Results & Conclusion: The comparison of DNA bands between Mycobacterium tuberculosis strains and standard H37rv revealed two common pulsotype ever known.