Prevalence and Molecular characterization of multi drug resistant Mycobacterium tuberculosis in Khyber Pakhtoonkhwa

Abstract

Spoligotyping is highly reproducible, fast polymerase chain reaction (PCR) based approach for identification of different strains of Mycobacterium tuberculosis through genotyping of Mycobacterium tuberculosis complex (MTB). Molecular typing of MTB is helpful for understanding and controlling TB epidemics. Spoligotyping was performed on 166 strains of MTB collected from 25 districts of Khyber Pakhtunkhwa, Pakistan. Results were analyzed using online database, SITVIT2, developed by Institute Pasteur de Guadeloupe, France and SPSS software V.15 (IMB Inc). Drug susceptibility test (DST) was performed on all strains using commercial liquid media in BACTECMGIT 960 instrument. Spoligotyping results showed that 145(88%) strains displayed known patterns while 21 (12%) were new. Central Asian strain (CAS) was the predominant family (73%, x2=19.9, P=0.001) followed by Beijing (5.4%) and T1 (4.2%). CAS1-Dehli was the major sub-family (82%) among the CAS family (x2=664, P=0.0001). Furthermore, new spoligotyping patterns were clustered using maximum parsimony (MP) test to find any evolutionary relationship with pre published genotypes. Analysis showed that majority of the strains with unknown pattern have evolutionary link with CAS strain and 9 (5.4%) of unknown strains, were epidemiologically linked and was named CAS-KPK (Khyber Pakhtunkhwa). The present study demonstrated that CAS is a predominant strain of MTB prevailing in different areas of KPK province of Pakistan. Spoligotyping pattern of some strains could not match to other reported pattern in international database. Other tools like MIRU/ VNTR will be helpful to perform investigation of its epidemiological characteristics in future. Keywords: spoligotyping, VNTR, DST, CAS,TB-SPRINT,