Molecular typing of Neisseria gonorrhoeae

Abstract

Phenotypic characterization of Neisseria gonorrhoeae by auxotype-serovar (A/S) classification is currently the most widely established method for differentiation of gonococci. However, the A/S classification system has some major limitations such as non-repoducibility of serotyping, especially when different batches of monoclonal antibody typing reagents are used, and the inability to differentiate strains present within major serovars. To overcome some of the limitations of the A/S classification system, newer molecular typing approaches such as restriction endonuclease analysis (REA), pulsed-field gel electrophoresis (PFGE) based on the contour-clamped, homogenous electric field electrophoresis (CHEF) technique, restriction fragment length polymorphisms of rRNA genes, multilocus enzyme electrophoretic analysis, opa-typing, direct sequencing of PIB gene and several PCR-based forms of analysis have been developed. Most of the molecular typing methods have been shown to have greater discriminatory power than serotyping. Further evaluation and comparison of the various molecular typing methods in terms of reproducibility and discriminatory power, using larger sample size of defined clinical and epidemiological origins, are needed.