title: 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.
abstract: 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.
authors.affiliation: Department of Immunology, Tuberculosis Research Centre, Chetput, Madras, India.
authors.forename: R
authors.initials: R
authors.lastname: Sahadevan
authors.forename: S
authors.initials: S
authors.lastname: Narayanan
authors.forename: C N
authors.initials: CN
authors.lastname: Paramasivan
authors.forename: R
authors.initials: R
authors.lastname: Prabhakar
authors.forename: P R
authors.initials: PR
authors.lastname: Narayanan
mesh_terms: D015373:Bacterial Typing Techniques; D001483:Base Sequence; D006801:Humans; D007194:India / Q000453:epidemiology; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics; D015345:Oligonucleotide Probes; D012150:Polymorphism, Restriction Fragment Length; D012008:Recurrence; D012091:Repetitive Sequences, Nucleic Acid; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D015345:Oligonucleotide Probes