title: Stability of Mycobacterium tuberculosis DNA genotypes.
abstract: To assess genotype stability in Mycobacterium tuberculosis, DNA genotypes were compared in sequential isolates from 49 patients who had sputum cultures separated by at least 90 days that grew M. tuberculosis. By use of IS6110 and the polymorphic GC-rich sequence (PGRS) as markers, it was found that paired isolates from 14 (29%) of 49 patients showed changes in their DNA genotypes between isolates (12 in IS6110 genotypes and 2 in PGRS genotypes). Changed IS6110 genotypes were confined to strains with 8-14 bands and were not related to the bacterial drug susceptibility, the patients' human immunodeficiency virus serostatus, or adherence to therapy. Although this rate of change complicates the interpretation of molecular epidemiologic studies, it can be exploited to gain additional insight into disease transmission. Furthermore, IS6110-related mutations may be a major source of genetic plasticity in M. tuberculosis and provide insights into the organism's evolution and virulence.
authors.affiliation: Department of Medicine, Stanford University School of Medicine, CA 94305, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Yeh
authors.forename: A
authors.initials: A
authors.lastname: Ponce de Leon
authors.forename: C B
authors.initials: CB
authors.lastname: Agasino
authors.forename: J A
authors.initials: JA
authors.lastname: Hahn
authors.forename: C L
authors.initials: CL
authors.lastname: Daley
authors.forename: P C
authors.initials: PC
authors.lastname: Hopewell
authors.forename: P M
authors.initials: PM
authors.lastname: Small
mesh_terms: D000995:Antitubercular Agents / Q000627:therapeutic use; D001482:Base Composition; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000032:analysis*; D018562:Disease Transmission, Infectious; D004352:Drug Resistance, Microbial / Q000235:genetics; D005819:Genetic Markers; D005838:Genotype; D006679:HIV Seropositivity; D006801:Humans; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D010349:Patient Compliance; D011110:Polymorphism, Genetic; D014376:Tuberculosis / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: D000995:Antitubercular Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005819:Genetic Markers