Genetic diversity of Neisseria gonorrhoeae IB-2 and IB-6 isolates revealed by whole-cell repetitive element sequence-based PCR.

Phenotypic characterization of 19 Neisseria gonorrhoeae serovar IB-2 and 8 serovar IB-6 isolates by the combined use of auxotypes, serological characterization, and penicillin susceptibility testing indicated intraserovar genetic diversity. In the present study, we applied whole-cell repetitive element sequence-based PCR (rep-PCR) analysis which allows a rapid assessment of the clonal relationships of IB-2 and IB-6 isolates. DNA templates were prepared by boiling cells harvested directly from plate cultures, eliminating the need for time-consuming phenol extraction. Six different rep-PCR profiles were established among the 19 IB-2 isolates. Rep-PCR typing results had a good correlation with pulsed-field gel electrophoresis patterns. It is slightly less discriminatory than BglII-generated macrorestriction pattern analysis by pulsed-field gel electrophoresis. It is capable of discriminating epidemiologically related from epidemiologically unrelated IB-2 isolates. It should serve as a rapid and useful subtyping tool for epidemiologic investigations in which there is a predominance of major serovar groups.