title: Sequencing of hsp65 distinguishes among subsets of the Mycobacterium avium complex.
abstract: The Mycobacterium avium complex consists of epidemiologically distinct subsets. The classification of these subsets is complicated by a number of factors, including the ambiguous results obtained with phenotypic and genetic assays and the recent appreciation that human and avian strains appear to be distinct. In previous work, sequencing based on a 441-bp portion of the hsp65 gene has proven to efficiently classify isolates within the Mycobacterium genus but provides low resolution for distinguishing among members of the M. avium complex. Therefore, in this study, we have targeted the more variable 3' region of the hsp65 gene to determine whether it can effectively discriminate M. avium complex isolates at the levels of species and subspecies. Primers designed for this target consistently generated amplicons for all organisms classified as M. avium complex. Sequences obtained indicate that M. intracellulare is genetically divergent from M. avium organisms, and distinct sequevars were obtained for M. avium subsets, including M. avium subsp. avium (bird type), M. avium subsp. hominissuis, and M. avium subsp. paratuberculosis. In addition, sequence differences served to distinguish bovine from ovine strains of M. avium subsp. paratuberculosis. A unique profile for M. avium subsp. silvaticum was not obtained. These results indicate that sequencing the 3' region of the hsp65 gene can simply and unambiguously distinguish species and subspecies of the M. avium complex.
authors.affiliation: Division of Infectious Diseases and Medical Microbiology, A5-156, Montreal General Hospital, 1650 Cedar Avenue, Montreal, QC H3G 1A4 Canada.
authors.forename: Christine Y
authors.initials: CY
authors.lastname: Turenne
authors.forename: Makeda
authors.initials: M
authors.lastname: Semret
authors.forename: Debby V
authors.initials: DV
authors.lastname: Cousins
authors.forename: Desmond M
authors.initials: DM
authors.lastname: Collins
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Behr
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D015373:Bacterial Typing Techniques; D002417:Cattle; D018834:Chaperonin 60; D018833:Chaperonins / Q000737:chemistry / Q000235:genetics*; D017931:DNA Primers; D006801:Humans; D008969:Molecular Sequence Data; D015269:Mycobacterium avium Complex / Q000145:classification* / Q000235:genetics; D015270:Mycobacterium avium-intracellulare Infection / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D017931:DNA Primers; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins