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R Sahadevan

Publications and source records attributed to R Sahadevan.

5 recordsLinked to original sources
PubMed1997

Restriction fragment length polymorphism of Mycobacterium tuberculosis strains from various regions of India, using direct repeat probe.

Intraspecies differentiation was studied on 68 M. tuberculosis strains obtained from 6 states of India by restriction fragment length polymorphism (RFLP) using a direct repeat probe (DR probe) hybridised with Alu I digest of DNA. Most strains showed polymorphism based patterns that comprised between 2 to 7 bands and were grouped into 26 RFLP types. Of the 11 strains tested from Amritsar, 8 were RFLP type 5; the remaining 3 were of type 11 and were exclusively confined to this region. The strains from other regions were more heterogeneous. We confirm that DR-associated RFLP can be an excellent tool for the differentiation of M. tuberculosis strains. Depending on their geographical origin, these strains can be differentiated to a large extent by DR fingerprinting.

DNA Fingerprinting↗
PubMed1995

Restriction fragment length polymorphism typing of clinical isolates of Mycobacterium tuberculosis from patients with pulmonary tuberculosis in Madras, India, by use of direct-repeat probe.

Large numbers of Mycobacterium tuberculosis isolates that were obtained from patients' sputa on diagnosis and during follow-up after short-course chemotherapy in Madras, India, have either no copy or only a single copy of IS6110. This poses a limitation for DNA fingerprinting with an IS6110-based probe to determine the frequency of exogenous reinfection versus that of endogenous reactivation. In the present study, we overcame this limitation by using an alternate probe, the direct-repeat element. Comparison of pre- and posttreatment isolates by direct-repeat restriction fragment length polymorphism analysis indicated a high degree of endogenous reactivation among patients who have relapses after the successful completion of chemotherapy.

Bacterial Typing Techniques↗