Vir typing: a long-PCR typing method for group A streptococci

PCR Methods Appl. 1995 Apr;4(5):288-93. doi: 10.1101/gr.4.5.288.


We have developed a new procedure (Vir typing) for typing Streptococcus pyogenes, by amplifying the entire 5- to 7-kb variable vir regulon by long PCR. The amplified DNA is then cleaved with HaeIII and visualized by ethidium bromide fluorescence after agarose gel electrophoresis. A simple procedure for preparing DNA of sufficiently high quality from 96 samples was employed simultaneously. This DNA was also used to develop a random amplified polymorphic DNA (RAPD) procedure. The discriminatory power of the two DNA-based procedures was compared with previous methods, M typing, and multilocus enzyme electrophoresis. Both procedures were highly discriminatory, but the stoichiometric yield of restriction fragments in Vir typing allows unambiguous interpretation of results.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Base Sequence
  • DNA Primers
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Endodeoxyribonucleases / genetics
  • Humans
  • Molecular Sequence Data
  • Polymerase Chain Reaction / methods*
  • Polymorphism, Genetic
  • Regulon
  • Restriction Mapping
  • Sensitivity and Specificity
  • Streptococcal Infections / microbiology*
  • Streptococcal Infections / transmission
  • Streptococcus pyogenes / classification*
  • Streptococcus pyogenes / genetics
  • Streptococcus pyogenes / isolation & purification
  • Virulence Factors*


  • Bacterial Proteins
  • DNA Primers
  • DNA, Bacterial
  • Virulence Factors
  • Endodeoxyribonucleases