Bouvet A, Villeroy F, Cheng F, Lamesch C, Williamson R, Gutmann L
J Clin Microbiol. 1985 Dec;22(6):1030-4. doi: 10.1128/jcm.22.6.1030-1034.1985.
A comparative study of 60 strains of nutritionally variant streptococci (NVS) with 34 strains of Streptococcus mitis and 37 strains of Streptococcus sanguis II showed the presence of a red chromophore which was absent in the other streptococcal species. By using the conventional microbiological tests, only small differences were found between the NVS and the two other related species. In contrast a clear-cut delineation was found by the API 20 Strep system of identification. All NVS contained pyrrolidonylarylamidase, an enzyme which was absent in S. mitis and S. sanguis II strains, and lacked the alkaline phosphatase enzyme which was present in 56% of S. mitis strains and 62% of S. sanguis II strains. According to the additional enzymatic and biochemical tests of the API 20 Strep system, there were three biotypes among NVS. The major biotype included 33 of 60 strains which were characterized by the presence of both alpha- and beta-galactosidases and the capacity to hydrolyze trehalose. This biotype also showed a specific pattern of penicillin-binding proteins. These results show that NVS are recognized as a separate variety distinct from S. mitis and S. sanguis II species, despite some common biochemical properties. Moreover, the delineation of 33 strains with a specific biotype and a specific penicillin-binding protein pattern strongly suggests that a large part of NVS strains belong to an individual species.
对60株营养变异型链球菌（NVS）与34株缓症链球菌和37株血链球菌II进行的比较研究表明，NVS中存在一种红色发色团，而其他链球菌种中不存在。通过常规微生物学检测，NVS与其他两个相关菌种之间仅发现微小差异。相比之下，API 20 Strep鉴定系统则能清晰区分。所有NVS都含有吡咯烷酮芳基酰胺酶，缓症链球菌和血链球菌II菌株中不存在这种酶，且NVS缺乏碱性磷酸酶，而56%的缓症链球菌菌株和62%的血链球菌II菌株中存在该酶。根据API 20 Strep系统的额外酶学和生化检测，NVS中有三种生物型。主要生物型包括60株中的33株，其特征是同时存在α-和β-半乳糖苷酶以及水解海藻糖的能力。这种生物型还显示出特定的青霉素结合蛋白模式。这些结果表明，尽管NVS具有一些共同的生化特性，但它被认为是一个与缓症链球菌和血链球菌II不同的独立变种。此外，33株具有特定生物型和特定青霉素结合蛋白模式的菌株的区分强烈表明，很大一部分NVS菌株属于一个单独的菌种。
