title: Mycobacterium colombiense sp. nov., a novel member of the Mycobacterium avium complex and description of MAC-X as a new ITS genetic variant.
abstract: Forty-five mycobacterial strains isolated from 23 Colombian HIV-positive patients were identified as members of the Mycobacterium avium complex (MAC) and were characterized using different molecular approaches. Seven of the isolates showed characteristic features that allowed them to be differentiated from other members of the complex. The isolates had a novel 16S-23S rRNA internal transcribed spacer (ITS 1) gene sequence which is described as a new sequevar, MAC-X. All of the seven novel isolates gave a positive result with the MAC-specific AccuProbe (Gen-Probe), but tested negative for Mycobacterium avium and Mycobacterium intracellulare species-specific probes (64 and 100 % of the isolates, respectively). The novel isolates could be differentiated phenotypically from other members of the MAC on the basis of the production of urease and by a consistent mycolic acid pattern. The novel isolates shared some characteristics with M. avium, such as the avium variant I (av-I) pattern of the hsp65 gene as determined by PCR restriction analysis and a positive PCR result for the mig (macrophage-induced) gene. However, the novel isolates showed a unique 16S rRNA gene sequence. DNA-DNA relatedness values, from 24 to 44 %, confirmed the distinction of the novel isolates from other members of the MAC at the genetic level and their status as members of a separate species. The novel isolates are proposed as representatives of a novel species, Mycobacterium colombiense sp. nov., that is closely related to M. avium within the MAC. The type strain is 10B(T) (=CIP 108962(T)=CECT 3035(T)).
authors.affiliation: Departamento de Microbiologia, Facultad de Medicina, Universidad Nacional, Bogota, Colombia.|Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain.
authors.forename: Martha I
authors.initials: MI
authors.lastname: Murcia
authors.affiliation: Centro Regionale di Riferimento per la Diagnostica dei Micobatteri, Laboratorio di Microbiologia e Virologia, Ospedale di Careggi, 50134 Firenze, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Tortoli
authors.affiliation: Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Menendez
authors.affiliation: Servicio de Microbiologia, Hospital General Universitario Doce de Octubre, Madrid, Spain.
authors.forename: Elia
authors.initials: E
authors.lastname: Palenque
authors.affiliation: Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Garcia
mesh_terms: D015373:Bacterial Typing Techniques; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis; D021901:DNA, Intergenic / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D006801:Humans; D008969:Molecular Sequence Data; D015269:Mycobacterium avium Complex / Q000145:classification* / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000032:analysis* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D021901:DNA, Intergenic; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S