Opa-typing: a high-resolution tool for studying the epidemiology of gonorrhoea

Mol Microbiol. 1995 Sep;17(5):865-75. doi: 10.1111/j.1365-2958.1995.mmi_17050865.x.


A single gonococcus possesses a family of 11 distinct and highly variable opa genes. The extensive variation and rapid evolution of the opa gene repertoire has been exploited to provide a high-resolution typing method for studies of the short-term transmission of gonorrhoea. The 11 opa genes are amplified with a single pair of primers by the polymerase chain reaction, digested with frequently-cutting restriction enzymes, and the fragments are fractionated on polyacrylamide to provide an opa-type. The method appeared to be highly discriminatory as the opa-types of gonococci, isolated world-wide over the last 30 years, were all different. Opa-typing discriminated between isolates of the same auxotype/serovar class. Similarly, there were 41 opa-types among 43 consecutive isolates from a sexually transmitted disease (STD) clinic. The two pairs of isolates from this clinic that gave the same opa-types were identical by other criteria and may have been from unsuspected sexual contacts. With one minor exception, identical opa-types were obtained from gonococci recovered from known sexual contacts. These results suggest that variation in the family of 11 opa genes evolves so rapidly that the opa-types of gonococci are distinguishable, unless the isolates are from sexual contacts or a short chain of disease transmission. The identification of gonococci with identical opa-types is therefore believed to be a good indicator that the individuals from which they were recovered were sexual partners, or part of a short chain of disease transmission.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial / genetics*
  • Bacterial Outer Membrane Proteins / genetics
  • Base Sequence
  • Chromosomes, Bacterial
  • DNA Fingerprinting
  • DNA Primers
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Genes, Bacterial*
  • Genetic Variation
  • Gonorrhea / epidemiology*
  • Gonorrhea / microbiology
  • Gonorrhea / transmission
  • Humans
  • Molecular Sequence Data
  • Neisseria gonorrhoeae / classification
  • Neisseria gonorrhoeae / genetics*
  • Neisseria gonorrhoeae / isolation & purification
  • Polymerase Chain Reaction
  • Reproducibility of Results


  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • DNA Primers
  • DNA, Bacterial
  • opacity proteins