Detection of Isoniazid-Resistant Clinical isolates of Mycobacterium tuberculosis from India using Ser315Thr marker by Comparison of molecular methods

International Journal of Molecular and Clinical Microbiology

مقاله 1، دوره 1، شماره 2، اسفند 2011، صفحه 52-59   

نوع مقاله: Research Article

نویسندگان

Nusrath Unissa^* ؛ Sujatha Narayanan؛ C. Suganthi؛ N. Selvakumar

National Institute for Research in Tuberculosisº Chetpet, Chennai-600031, India

چکیده

In this study, Substitution at codon Ser315 of katG gene, a reliable marker for isoniazid (INH) resistance was analyzed and compared by three molecular methods such as DNA  sequencing, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and PCR-single strand conformation polymorphism (PCR-SSCP) in 105 phenotypically resistant isolates obtained from various parts of India. Out of the 105 resistant isolates, 64 (61%) were found to be resistant by DNA sequencing, 54 (51%) by PCR-RFLP and 57 (54%) by PCR-SSCP methods. The results obtained using PCR-SSCP and PCR-RFLP methods were compared with those from DNA sequencing (gold standard). The sensitivity and specificity of PCR-RFLP were 84% and 100% respectively and corresponding values for PCR-SSCP method were 89% and 95% respectively.  The study has shown the comparison of the simple, rapid and cost effective methods with DNA sequencing targeting codon Ser315 of katG gene and suggests that PCR-RFLP and PCR-SSCP may be performed as alternative inexpensive methods in settings with a high prevalence of INH-resistant M. tuberculosis strains where sequencing cannot be afforded.

کلیدواژه‌ها

Mycobacterium tuberculosis؛ isoniazid resistance؛ DNA sequencing؛ PCR-SSCP؛ PCR-RFLP