title: Molecular typing of Mycobacterium avium isolates by sequencing of the 16S-23S rDNA internal transcribed spacer and comparison with IS1245-based fingerprinting.
abstract: The nucleotide sequence of the variable 16S-23S rDNA internal transcribed spacer (ITS) was determined in 32 strains of Mycobacterium avium, including 29 clinical isolates, two environmental isolates and the reference strain M. avium ATCC 35712. The results were compared with those obtained by the IS1245-based restriction fragment length polymorphism (RFLP) assay. The strains belonged to three distinct ITS sequevars, Mav-A, Mav-B and Mav-C. Sixteen of 17 isolates of the Mav-B sequevar were from HIV-positive patients; the Mav-A sequevar included six and five isolates from HIV-positive and HIV-negative individuals, respectively, as well as the two environmental isolates and the M. avium reference strain ATCC 35712; only one isolate, from a HIV-infected patient, belonged to the Mav-C sequevar. IS1245-RFLP analysis of M. avium isolates of sequevars Mav-A and Mav-B showed that isolates occurring in clusters of identical or highly related RFLP patterns generally belong to the same sequevar, and that M. avium strains belonging to the same sequevar may present distinct and unrelated IS1245-RFLP patterns. The question of the molecular markers specific for M. avium clones pathogenic for man is discussed.
authors.affiliation: Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università di Pisa, I-56127 Pisa, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Novi
authors.affiliation: Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università di Pisa, I-56127 Pisa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Rindi
authors.affiliation: Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università di Pisa, I-56127 Pisa, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Lari
authors.affiliation: Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università di Pisa, I-56127 Pisa, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Garzelli
mesh_terms: D000818:Animals; D001483:Base Sequence; D016172:DNA Fingerprinting / Q000379:methods*; D004251:DNA Transposable Elements / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D004783:Environmental Microbiology; D020459:Genes, rRNA / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009162:Mycobacterium avium / Q000145:classification / Q000235:genetics; D015269:Mycobacterium avium Complex / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: D004251:DNA Transposable Elements; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S