Detection of genomic heterogeneity in Streptococcus suis isolates by DNA restriction fragment length polymorphisms of rRNA genes (ribotyping).
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.
Okwumabua
O
O
Department of Pathology and Microbiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA.
Staats
J
J
Chengappa
M M
MM
D000818:Animals; D004269:DNA, Bacterial / Q000235:genetics; D018076:DNA, Complementary; D005819:Genetic Markers; D014644:Genetic Variation; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics*; D012703:Serotyping; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D013552:Swine / Q000382:microbiology
D004269:DNA, Bacterial; D018076:DNA, Complementary; D005819:Genetic Markers; D012329:RNA, Bacterial; D012335:RNA, Ribosomal