Opa-typing: a high-resolution tool for studying the epidemiology of gonorrhoea.
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.
O'Rourke
M
M
Molecular Microbiology Group, School of Biological Sciences, University of Sussex, Brighton, UK.
Ison
C A
CA
Renton
A M
AM
Spratt
B G
BG
D000942:Antigens, Bacterial / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001483:Base Sequence; D002876:Chromosomes, Bacterial; D016172:DNA Fingerprinting; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005798:Genes, Bacterial; D014644:Genetic Variation; D006069:Gonorrhea / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D006801:Humans; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; C050308:opacity proteins