Multiple copies of the 16S rRNA gene in Nocardia nova isolates and implications for sequence-based identification procedures.
Multiple copies of the 16S rRNA gene in Nocardia nova isolates and implications for sequence-based identification procedures.
复制标题
新诺卡氏菌分离株中 16S rRNA 基因的多个拷贝及其对基于序列的鉴定程序的影响。
DOI：
10.1128/jcm.43.6.2881-2885.2005
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发表时间：
2005
影响因子：
9.4
通讯作者：
Witebsky,FrankG
中科院分区：
文献类型：
--
作者：
Conville,PatriciaS;Witebsky,FrankG
Molecular investigation of twoNocardiapatient isolates showed unusual restriction fragment length polymorphism patterns with restriction endonuclease assays (REA) using an amplified portion of the 16S rRNA gene. Patterns typical ofNocardia novawere obtained with REA of an amplified portion of the 65-kDa heat shock protein gene. Subsequent sequence analysis of the 16S rRNA gene regions of these isolates showed the presence of ambiguous bases within an expected restriction endonuclease recognition site which were not able to be resolved on repeat testing. Cloning of amplified regions of the 16S rRNA genes and subsequent sequencing of the resulting clones from the two patient isolates showed three different 16S rRNA gene sequences which corresponded to sequences found inN. nova, a molecular variant ofN. nova, and a previously undescribed sequence. Hybridization studies using a DNA probe corresponding to an 89-bp conserved region of the 16S rRNA gene confirmed the presence of at least two copies of the 16S rRNA gene in theN. novatype strain, in a patient isolate identical to the molecular variant ofN. nova, and in the two other patient isolates. All isolates were found to belong to the speciesN. novaas determined by DNA-DNA hybridization. Because minimal variation has been found in the 16S rRNA gene sequences of different species ofNocardia, those laboratories employing molecular methods for identification of these species must be aware of the potential identification complications that may be caused by the presence of differing 16S rRNA genes in the same isolate.
