title: Molecular epidemiology of Mycobacterium tuberculosis strains isolated from patients in a human immunodeficiency virus cohort in Switzerland.
abstract: From 1989 to 1995, 46 patients infected with the human immunodeficiency virus were diagnosed with tuberculosis at the University Hospital in Zurich. Using the IS6110 insertion sequence as a genetic marker, restriction fragment length polymorphism analyses were done for 52 Mycobacterium tuberculosis isolates. We have found a large degree of IS6110 polymorphism, ranging from 1 to 16 copies. For isolates from patients from whom multiple isolates had been available, the IS6110 pattern remained virtually stable over a period of up to 4 years, as well as during emerging drug resistance. In none of the cases was a reinfection of a patient with another strain detected. For isolates from 10 patients we detected identical patterns which could be associated with four clusters. In one of these, the strains exhibited a low IS6110 copy number (four bands), and the strains were further analyzed by hybridizing with (i) the polymorphic GC-rich repetitive sequence (PGRS) and (ii) the 36-bp direct-repeat (DR) cluster sequence. One of these isolates had a different pattern with the PGRS as well as with the DR sequence and could therefore be safely excluded from that cluster. These findings point to the importance of applying more than one genetic criterion in the molecular biological study of strain relatedness.
authors.affiliation: Department of Medical Microbiology, Swiss National Center for Mycobacteria, University of Zurich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Strässle
authors.forename: J
authors.initials: J
authors.lastname: Putnik
authors.forename: R
authors.initials: R
authors.lastname: Weber
authors.forename: A
authors.initials: A
authors.lastname: Fehr-Merhof
authors.forename: J
authors.initials: J
authors.lastname: Wüst
authors.forename: G E
authors.initials: GE
authors.lastname: Pfyffer
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology* / Q000382:microbiology; D000328:Adult; D015331:Cohort Studies; D004251:DNA Transposable Elements; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D015345:Oligonucleotide Probes; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid; D013557:Switzerland / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D005819:Genetic Markers; D015345:Oligonucleotide Probes