MOLECULAR-GENETIC ANALYSIS OF MULTIDRUG-RESISTANCE IN INDIAN ISOLATESOF MYCOBACTERIUM-TUBERCULOSIS

A total of 116 isolates from patients attending the out-patient depart ment at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbio logical techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were fu rther characterized at molecular level. The multi-drug loci correspond ing to rpo beta, gyr A, kat G were studied for mutation(s) by the poly merase chain reaction-single strand conformational polymorphism (PCR-S SCP) technique. the SSCP positive samples were sequenced to characteri ze the mutations in rpo beta, and rpo A loci. While previously reporte d mutations in the gyr A and rpo beta loci were found to be present, s everal novel mutations were also scored in rpo beta locus.