一株罕见手感染克罗彭斯特诺卡菌的鉴定

The identification on an uncommon infection of Nocardia Kroppenstedtii in hand

目的探讨如何鉴定一株罕见克罗彭斯特菌诺卡菌的鉴定方法。方法将一株从患者手分离出来的菌株,采用细菌形态学观察、菌落生化特性分析、遗传学分析(如质谱技术、16S r RNA基因扩增后做靶向DNA测序)等相结合的方法进行鉴定。结果临床分离的该罕见菌通过镜下菌体典型特征(革兰染色呈90°分枝角G+分枝菌丝,改良Kinyoun染色为阳性);在血平板、巧克力平板生长缓慢,菌落细小,时间延长起皱褶;触酶阳性,分解葡萄糖、七叶苷、尿素酶,不分解甘露醇、肌醇、明胶;经16S r RNA基因扩增后做靶向DNA测序等综合分析,最后鉴定为克罗彭斯特诺卡菌(Norcardia Kroppenstedtii)。结论各实验室可依据细菌形态学特征、菌落生化特性结合遗传学分析(如16S r RNA基因扩增后进行靶向DNA测序)鉴定诺卡菌属,可及时、准确鉴定出克罗彭斯特诺卡菌这类生长缓慢、罕见菌种。

Objective To explore the method to identify the rare Nocardia Kroppenstedtii. Methods After isolating a strain from a patient＇ s hand, the method of combining bacterial morphology, colony biochemical characteristics analysis, genetic analysis （such as mass spectrometry, sequencing targeting DNA after 16S rRNA gene amplification） etc. were used for the identification. Results Observed through microscope,the rare bacteria by the clinical isolates had typical cell feature （the result of Gram stain shows 90° branching angle and G＋ branching hyphae and improved Kinyoun staining shows positive resuh）,slow growth in blood agar and chocolate plate, small colonies, extended time to fold, catalase positive, breakdown of glucose, Esculin, urease, not broken down mannitol, inositol, gelatin. Then a comprehensive analysis included targeting DNA sequencing after 16S rRNA gene amplification was analyzed, and it was finally identified as Noeardia Kroppenstedtii. Conclusion Morphology observation, colony sublimation characteristic analysis and genetic analysis （such as sequencing targeting DNA after 16S rRNA gene amplification） any laboratory can identify Nocardia and can quickly, accurately identify Nocardia Kroppenstedtii, which is a type of rare strain with slow growth.