RESUMO
A group of pigmented, slowly growing mycobacteria identified by 16S rRNA gene sequencing as 'MCRO 33' (GenBank accession no. AF152559) have been isolated from several clinical specimens in various laboratories across Canada. Genotypically, the organism is most closely related to Mycobacterium simiae. However, it presents with a similar phenotypic profile to Mycobacterium scrofulaceum. Several reference strains obtained from ATCC and TMC culture collections, previously identified as M. scrofulaceum or M. simiae, have also been found to possess the MCRO 33 16S rRNA gene sequence. Biochemical testing, susceptibility testing, HPLC, hsp65 gene and 16S-23S spacer (ITS1) sequencing were performed on clinical and reference strains to characterize further this unique species. Of the clinical strains, one was isolated from a cervix biopsy whereas all other clinical isolates were obtained from respiratory samples. In one patient, symptoms, imaging and repeat clinical specimens positive on culture for this organism were suggestive of active clinical disease. The description of this species, for which the name Mycobacterium parascrofulaceum sp. nov. is proposed, follows the present trend of a large number of novel Mycobacterium species identified due in great part to sequence-based methods. The type strain is HSC68T (= ATCC BAA-614T = DSM 44648T).
Assuntos
Infecções por Mycobacterium/microbiologia , Micobactérias não Tuberculosas/classificação , Micobactérias não Tuberculosas/isolamento & purificação , Adulto , Idoso , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Líquido da Lavagem Broncoalveolar/microbiologia , Canadá , Colo do Útero/microbiologia , Chaperonina 60 , Chaperoninas/genética , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/isolamento & purificação , Feminino , Genes de RNAr , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium scrofulaceum/classificação , Ácidos Micólicos/análise , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/fisiologia , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Escarro/microbiologiaRESUMO
A pigmented, slowly growing Mycobacterium avium complex AccuProbe-positive organism was isolated from the sputum and pleural fluid of a 72-year-old female with bronchiectasis. The unusual morphology of the organism prompted further identification by 16S rRNA gene sequencing, revealing a perfect identity with previously uncharacterized strain Mycobacterium sp. MCRO 8 (GenBank accession no. X93034), with the closest established species by 16S rDNA analysis being Mycobacterium interjectum. HPLC of the organism corresponded to previously obtained patterns identified as M. interjectum-like and, upon sequence evaluation of a selection of strains with a similar profile, more were subsequently identified as MCRO 8. A total of 16 strains isolated from human respiratory samples were evaluated in the characterization of this novel species, for which the name Mycobacterium saskatchewanense sp. nov. is proposed. The type strain is strain 00-250(T) (=ATCC BAA-544(T)=DSM 44616(T)=CIP 108114(T)).
