Affiliation:
1. Microbiology Service, Department of Laboratory Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland
Abstract
ABSTRACT
Molecular methodologies, especially 16S rRNA gene sequence analysis, have allowed the recognition of many new species of
Nocardia
and to date have been the most precise methods for identifying isolates reliably to the species level. We describe here a novel method for identifying
Nocardia
isolates by using sequence analysis of a portion of the
secA1
gene. A region of the
secA1
gene of 30 type or reference strains of
Nocardia
species was amplified using
secA1-
specific primers. Sequence analysis of 468 bp allowed clear differentiation of all species, with a range of interspecies similarity of 85.0% to 98.7%. Corresponding 16S rRNA gene sequences of a 1,285-bp region for the same isolates showed a range of interspecies similarity of 94.4 to 99.8%. In addition to the type and reference strains, a 468-bp fragment of the
secA1
gene was sequenced from 40 clinical isolates of 12
Nocardia
species previously identified by 16S rRNA gene sequence analysis. The
secA1
gene sequences of most isolates showed >99.0% similarity to the
secA1
sequences of the type or reference strain to which their identification corresponded, with a range of 95.3 to 100%. Comparison of the deduced 156 amino acid sequences of the SecA1 proteins of the clinical isolates showed between zero and two amino acid residue differences compared to that of the corresponding type or reference strain. Sequencing of the
secA1
gene, and using deduced amino acid sequences of the SecA1 protein, may provide a more discriminative and precise method for the identification of
Nocardia
isolates than 16S rRNA gene sequencing.
Publisher
American Society for Microbiology
Reference13 articles.
1. Cloud, J. L., A. Croft, P. S. Conville, F. G. Witebsky, R. Yih, H. Chun, M. Martin, S. Ohlson, S. Hegewald, and K. C. Carroll. 2002. Evaluation of partial 16S ribosomal DNA sequencing for identification of Nocardia species by using the MicroSeq 500 system with an expanded database. J. Clin. Microbiol.42:578-584.
2. Nocardia kruczakiae
sp. nov., a Pathogen in Immunocompromised Patients and a Member of the “
N. nova
Complex”
3. Nocardia veterana
as a Pathogen in North American Patients
4. Identification of
Nocardia
Species by Restriction Endonuclease Analysis of an Amplified Portion of the 16S rRNA Gene
5. Multiple Copies of the 16S rRNA Gene in
Nocardia nova
Isolates and Implications for Sequence-Based Identification Procedures
Cited by
83 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献