背景：
首先从猪和兔中分离出链球菌（Streptococcus thoraltensis）。后来，记录了人类口腔和鼻腔以及喉咙和口咽的隔离情况。从患有牙周炎，扁桃体炎和绒毛膜羊膜炎的患者中分离出S.thoraltensis，表明在人类感染中可能具有病理作用。动物和人类起源的所有S.thoraltensis分离株对万古霉素敏感。

方法：
使用标准微生物鉴定方法，生化分析和使用盘扩散和E方法的抗生素敏感性测试。使用Vitek 2紧凑系统进行自动物种鉴定和抗生素敏感性测试。使用具有vanA的特异性引物的PCR进行万古霉素抗性基因的分子分析。

结果：
我们报告了一名健康的年轻女性成年人，年龄为19岁，有接触过鼻腔定植于S.thoraltensis的宠物兔的历史。 S.thoraltensis的鉴定基于传统的微生物学方法（培养，革兰氏染色和生化测试）和Vitek 2紧密系统，置信率为97％。该分离株的抗生素敏感性试验表明对大多数抗生素具有抗性，包括青霉素，头孢菌素，甲氧西林和糖肽。万古霉素和替考拉宁的最小抑制浓度异常高（>256μg/ mL）。分子分析表明S.thoraltensis中缺乏vanA基因。

结论：
我们首次报道了从健康的人类前鼻腔中分离出完全耐万古霉素的S.thoraltensis，而不依赖于vanA。这种新鉴定的生物体在人类感染中具有特别罕见的抗性模式的病理作用尚未确定。

BACKGROUND:
Streptococcus thoraltensis was first isolated from pigs and rabbits. Later, isolation from human oral and nasal cavities and from throat and oropharynx was documented. S. thoraltensis was isolated from patients with periodontitis, tonsillopharyngitis, and chorioamnionitis suggesting a possible pathological role in human infections. All S. thoraltensis isolates of animal and human origins were sensitive to vancomycin.

METHODS:
Standard microbiological identification methods, biochemical analysis, and antibiotic susceptibility testing using disk diffusion and E methods were used. Automatic species identification and antibiotic susceptibility testing were carried out using the Vitek 2 compact system. Molecular analysis of vancomycin resistance gene was carried out using a PCR with specific primers for vanA.

RESULTS:
We report a healthy young female adult, aged 19 years, with history of exposure to pet rabbit who had nasal colonization with S. thoraltensis. Identification of S. thoraltensis was based on traditional microbiological methods (culture, Gram stain, and biochemical tests), and the Vitek 2 compact system with 97% confidence rate. Antibiotic susceptibility testing of the isolate indicated resistance to most antibiotics, including penicillins, cephalosporins, methicillin, and glycopeptides. The minimal inhibitory concentration for vancomycin and teicoplanin was exceptionally high (>256 μg/mL). Molecular analysis indicated the absence of vanA gene in S. thoraltensis.

CONCLUSION:
We report for the first time the isolation of a fully vancomycin-resistant S. thoraltensis independent of vanA from a healthy human anterior nasal cavity. The pathological role of this newly identified organism with an exceptionally rare resistance pattern in human infections is yet to be identified.

https://www.ncbi.nlm.nih.gov/pubmed/30328745