Organisms Designated as
            <i>Nocardia asteroides</i>
            Drug Pattern Type VI Are Members of the Species
            <i>Nocardia cyriacigeorgica</i>

Conville, Patricia S.; Witebsky, Frank G.

doi:10.1128/jcm.00133-07

Cited by 46 publications

(29 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additional sequences should either reassign these isolates to type strain-defined species clusters or prompt the characterization of new species. The species or subspecies status of the three subclusters of N. cyriacigeorgica would benefit from further taxonomic investigation, especially considering its importance as a human pathogen (9,39 new species, provided that they fail to cluster with additional type strains when they are incorporated into the analysis. In all cases, novel species discovery must be supported by MLSA as well as DDH data, extensive biochemical and phenotypic characterizations, and perhaps ecological distinction (12,13,20,30,31).…”

Section: Discussionmentioning

confidence: 99%

Phylogeny and Identification of Nocardia Species on the Basis of Multilocus Sequence Analysis

et al. 2010

View full text Add to dashboard Cite

Nocardia species identification is difficult due to a complex and rapidly changing taxonomy, the failure of 16S rRNA and cellular fatty acid analysis to discriminate many species, and the unreliability of biochemical testing. Here, Nocardia species identification was achieved through multilocus sequence analysis (MLSA) of gyrase B of the ␤ subunit of DNA topoisomerase (gyrB), 16S rRNA (16S), subunit A of SecA preprotein translocase (secA1), the 65-kDa heat shock protein (hsp65), and RNA polymerase (rpoB) applied to 190 clinical, 36 type, and 11 reference strains. Phylogenetic analysis resolved 30 sequence clusters with high (>85%) bootstrap support. Since most clusters contained a single type strain and the analysis corroborated current knowledge of Nocardia taxonomy, the sequence clusters were equated with species clusters and MLSA was deemed appropriate for species identification. By comparison, single-locus analysis was inadequate because it failed to resolve species clusters, partly due to the presence of foreign alleles in 22.1% of isolates. While MLSA identified the species of the majority (71.3%) of strains, it also identified clusters that may correspond to new species. The correlation of the identities by MLSA with those determined on the basis of microscopic examination, biochemical testing, and fatty acid analysis was 95%; however, MLSA was more discriminatory. Nocardia cyriacigeorgica (21.58%) and N. farcinica (14.74%) were the most frequently encountered species among clinical isolates. In summary, five-locus MLSA is a reliable method of elucidating taxonomic data to inform Nocardia species identification; however, three-locus (gyrB-16S-secA1) or four-locus (gyrB-16S-secA1-hsp65) MLSA was nearly as reliable, correctly identifying 98.5% and 99.5% of isolates, respectively, and would be more feasible for routine use in a clinical reference microbiology laboratory.

show abstract

Section: Discussionmentioning

confidence: 99%

Phylogeny and Identification of Nocardia Species on the Basis of Multilocus Sequence Analysis

et al. 2010

View full text Add to dashboard Cite

show abstract

“…This is partly due to the discrepancy between the manufacturers' recommendations and the findings of Biehle et al, who demonstrated an ϳ1-log 10 -dilution-lower inoculum size when using the recommended 0.5 MacFarland suspension (2). Major taxonomic revisions have occurred within the last 10 years, further complicating the comparison of studies (7,11,12,21). With potentially important clinical and epidemiological differences between species, it is important to identify isolates to the species level as accurately and rapidly as possible.…”

mentioning

confidence: 98%

Antimicrobial Susceptibility Testing and Profiling of Nocardia Species and Other Aerobic Actinomycetes from South Africa: Comparative Evaluation of Broth Microdilution versus the Etest

Lowman

Aithma

2010

J Clin Microbiol

View full text Add to dashboard Cite

Nocardiosis is an underrecognized clinical entity in South Africa, for which interspecies epidemiological and clinical differences are poorly understood. The taxonomical state of flux and the lack of a simple antimicrobial susceptibility testing method are partly responsible. Definitive identification is molecularly based, which further complicates the study of this ubiquitous organism, as this methodology is beyond the scope of most routine diagnostic laboratories. The Etest methodology has been proposed as an alternative to the reference broth microdilution method, although there have been a limited number of comparative studies. We profiled 51 clinical isolates of aerobic actinomycetes, including 39 Nocardia species, using sequence-based (16S rRNA) identification. Broth microdilution and Etests were done concurrently on all isolates. The overall level of categorical and essential agreement for broth microdilution and Etest for the Nocardia isolates ranged from 67.5 to 100% and 46.2 to 81.6%, respectively. Very major errors were seen with amikacin, amoxicillinclavulanate, ciprofloxacin, clarithromycin, and imipenem. For Nocardia species, uniform susceptibility to co-trimoxazole, amikacin, and linezolid was demonstrated, with a 48.8% susceptibility rate to imipenem. Nocardia farcinica (20.5%) and Nocardia cyriacigeorgica (15.4%) were the most commonly identified species among the 82% of isolates identified to species level using 16S rRNA sequences. Furthermore, drug susceptibility patterns demonstrated limited concordance with species identification. Our results suggest that, in a routine diagnostic setting, the Etest is not an acceptable alternative to the reference method of broth microdilution for antimicrobial susceptibility testing. Given the diversity and limited understanding of this group of organisms, further widespread evaluation of clinical isolates, from both clinical and diagnostic perspectives, is warranted.

show abstract

“…However, Conville and Witebsky (17) confirmed that N. asteroides drug pattern VI, which since its description in 1988 has been considered the most commonly encountered group of Nocardia isolates recovered from clinical samples, is identical by DNA-DNA hybridization to the species N. cyriacigeorgica and, as such, should not be considered a "new or emerging species of Nocardia. "…”

Section: The "N Asteroides" Storymentioning

confidence: 85%

Current Status of Nocardia Taxonomy and Recommended Identification Methods

Conville

Wallace

2015

Clinical Microbiology Newsletter

View full text Add to dashboard Cite

Organisms Designated as Nocardia asteroides Drug Pattern Type VI Are Members of the Species Nocardia cyriacigeorgica

Cited by 46 publications

References 24 publications

Phylogeny and Identification of Nocardia Species on the Basis of Multilocus Sequence Analysis

Phylogeny and Identification of Nocardia Species on the Basis of Multilocus Sequence Analysis

Antimicrobial Susceptibility Testing and Profiling of Nocardia Species and Other Aerobic Actinomycetes from South Africa: Comparative Evaluation of Broth Microdilution versus the Etest

Current Status of Nocardia Taxonomy and Recommended Identification Methods

Contact Info

Product

Resources

About