DIFFERENTIATION OF NEISSERIA-GONORRHOEAE STRAINS BY POLYMERASE CHAIN-REACTION AND RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM OF OUTER-MEMBRANE PROTEIN IB GENES

Objectives-To employ polymerase chain reaction (PCR) and restriction f ragment length polymorphism (RFLP)analysis for the rapid differentiati on of Neisseria gonorrhoeae protein IB (PIE) isolates and to compare i ts usefulness with the widely accepted auxotype/serovar classification scheme. Methods-The outer membrane protein IB genes of 47 gonococcal isolates belonging to 10 different serovars were amplified by PCR. The similar to 1 kb DNA products were then digested separately with restr iction enzymes CfoI and MspA1I, and electrophoresed on agarose gels. R esults-Cleavage of PIB genes by MspA1I and CfoI differentiated all the N gonorrhoeae strains into five and six PCR-RFLP profiles, respective ly. PCR-RFLP was more discriminatory than auxotyping, which classifies the strains into only two auxotypes. Some strains belonging to common serovars could be further differentiated. A combination of PCR-RFLP a nalysis, serotyping further crimination of the strains into 34 subtype s. The PCR-RFLP method was easy to perform, reliable, reproducible, an d consistent with published nucleotide sequence data. Conclusion-The P CR-RFLP method can augment auxotyping and serotyping or be used as a p reliminary screening tool to differentiate N gonorrhoeae strains in ar eas where serotyping reagents are not easily available.