Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Disease, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
DSMZ - German Collection of Microorganisms and Cell Cultures, D-38124 Braunschweig, Germany.
Int J Syst Evol Microbiol. 2013 Mar;63(Pt 3):1056-1061. doi: 10.1099/ijs.0.039990-0. Epub 2012 Jun 15.
Five nocardioform isolates from human clinical sources were evaluated. Analysis of the nearly full-length 16S rRNA gene showed 99.9-100 % similarity among the strains. The results of a comparative phylogenetic analysis of the 16S rRNA gene sequences indicated that the isolates belonged to the genus Nocardia. Phenotypic and molecular analyses were performed on the clinical isolates. Traditional phenotypic analyses included morphological, biochemical/physiological, chemotaxonomic and antimicrobial susceptibility profiling. Molecular studies included 1441-bp 16S rRNA and 1246-bp gyrB gene sequence analyses, as well as DNA-DNA hybridizations. Biochemical analysis failed to differentiate the putative novel species from its phylogenetic neighbours; however, molecular studies were able to distinguish the patient strains and confirm them as members of a single species. Based on 16S rRNA gene sequence analysis, similarity between the isolates and their closest relatives (type strains of Nocardia araoensis, N. arthritidis, N. beijingensis and N. niwae) was ≤99.3 %. Analysis of partial gyrB gene sequences showed 98-99.7 % relatedness among the isolates. Nocardia lijiangensis and N. xishanensis were the closest related species to the isolates based on gyrB gene sequence analysis, and their type strains showed 95.7 and 95.3 % similarity, respectively, to strain W9988(T). Resistance to amikacin and molecular analyses, including DNA-DNA hybridization, distinguished the five patient strains from their phylogenetic neighbours, and the results of this polyphasic study indicated the existence of a novel species of Nocardia, for which we propose the name Nocardia amikacinitolerans sp. nov., with strain W9988(T) ( = DSM 45539(T) = CCUG 59655(T)) as the type strain.
从人类临床来源评估了五个诺卡氏菌样分离株。对近乎全长 16S rRNA 基因的分析表明，这些菌株之间的相似度为 99.9-100%。16S rRNA 基因序列比较系统发育分析的结果表明，这些分离株属于诺卡氏菌属。对临床分离株进行了表型和分子分析。传统的表型分析包括形态学、生化/生理、化学生态和抗菌敏感性分析。分子研究包括 1441-bp 16S rRNA 和 1246-bp gyrB 基因序列分析以及 DNA-DNA 杂交。生化分析未能将假定的新种与亲缘种区分开来；然而，分子研究能够区分患者株并证实它们为单一物种的成员。基于 16S rRNA 基因序列分析，分离株与其最亲近的亲缘种（诺卡氏菌 araoensis、N. arthritidis、N. beijingensis 和 N. niwae 的模式株）之间的相似性≤99.3%。gyrB 基因部分序列分析显示，分离株之间的相关性为 98-99.7%。基于 gyrB 基因序列分析，Nocardia lijiangensis 和 N. xishanensis 是与分离株最相关的种，其模式株与菌株 W9988(T) 的相似性分别为 95.7%和 95.3%。对阿米卡星的耐药性和分子分析，包括 DNA-DNA 杂交，将这 5 株患者株与亲缘种区分开来，多相研究的结果表明存在一种新型的诺卡氏菌，我们提议将其命名为 Nocardia amikacinitolerans sp. nov.，其模式株为 W9988(T)（=DSM 45539(T)=CCUG 59655(T)）。
