Okwumabua O, Staats J, Chengappa M M
Department of Pathology and Microbiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA.
J Clin Microbiol. 1995 Apr;33(4):968-72. doi: 10.1128/jcm.33.4.968-972.1995.
Whole-cell chromosomal digests of 54 isolates of Streptococcus suis encompassing all known serotypes from a geographically varied collection were examined by PstI restriction fragment length polymorphisms and then hybridized with a digoxigenin-11-dUTP-labeled cDNA probe transcribed from a mixture of 16S and 23S rRNAs from Escherichia coli MRE600. The hybridization patterns showed genetic heterogeneity within and between S. suis serotypes. Most isolates (87%) representing 28 serotypes contained a common band at approximately 1.8 kb. However, 13% of the isolates representing seven serotypes lacked the 1.8-kb band, indicating that the species as currently defined is diverse. Nonetheless, the 1.8-kb band may be a useful genotypic marker for identification of most S. suis isolates. We tested the ability of this technique to discriminate between virulent and avirulent S. suis type 2 isolates. A virulent strain of S. suis type 2 could be distinguished from avirulent strains by the presence of specific bands. No correlation was obvious between band pattern and hemolysin production.
对来自地理分布多样的54株猪链球菌分离株进行全细胞染色体消化，这些分离株涵盖了所有已知血清型，通过PstI限制性片段长度多态性进行检测，然后与用地高辛-11-dUTP标记的cDNA探针杂交，该探针由大肠杆菌MRE600的16S和23S rRNA混合物转录而来。杂交模式显示猪链球菌血清型内部和之间存在遗传异质性。代表28个血清型的大多数分离株（87%）在约1.8 kb处含有一条共同条带。然而，代表7个血清型的13%的分离株缺乏1.8 kb条带，这表明目前定义的该物种具有多样性。尽管如此，1.8 kb条带可能是鉴定大多数猪链球菌分离株的有用基因型标记。我们测试了该技术区分2型猪链球菌强毒株和无毒株的能力。2型猪链球菌的强毒株可通过特定条带的存在与无毒株区分开来。条带模式与溶血素产生之间没有明显的相关性。
