为快速、准确鉴定诺卡菌，首先设计针对诺卡菌rpoB、secA1、16S rRNA基因的引物，利用单个聚合酶链反应（PCR）和测序验证引物的特异度，建立多重PCR鉴定系统。在同一反应体系和条件下，对44株诺卡标准菌株、44株临床分离株和7株对照菌株进行扩增。结果显示，利用单对引物对其中2株诺卡菌（标准株DSM 43003、临床株CDC 51）进行扩增，出现的条带均为与目的片段长度一致的单一条带。经测序和基本局部比对搜索工具（BLAST）验证，扩增片段为目的基因。建立的多重PCR结果显示，44株诺卡菌标准珠中有43株（97.7%）、44株临床分离株中有42株（95.5%）rpoB、secA1、16S rRNA这3条片段均显示，7株对照菌株均未显示条带。结果提示，本研究证实建立的多重PCR简单、快速、灵敏度高、特异度好，适用于诺卡菌的快速鉴定。

In order to identify Nocardia quickly and accurately, three primers were designed for detection of rpoB, SecA1 and 16S rRNA genes. The specificity of simplex polymerase chain reaction (PCR) was verified. Then multiple PCR method was established, and the sensitivity and specificity were tested by 44 Nocardia standard strains, 44 clinical isolates and 7 reference strains under the same reaction system and condition. The results showes that 2 strains of Nocardia (DSM 43003 and CDC 51) were amplified by using a single primer pair, and the single bands obtained were consistent with target fragment. Then the target genes were verified by sequencing and Basic Local Alignment Search Tool (BLAST). With the established multiple PCR method, rpoB, SecA1 and 16S rRNA segments were confirmed in 43 (97.7%) of 44 Nocardia standard strains and 42 (95.5%) of 44 clinical isolates, however, there were no bands obtained in 7 reference strains. The specificity met the test requirement, and the detection limit for DNA template was 1×10^-4 ng. It is concluded that multiple PCR method is fast, accurate, specific and sensitive. It can be used for identifying Nocardia strains.