Molecular typing of Neisseria gonorrhoeae causing repeated infections: Evolution of porin during passage within a community

Thirty-three Neisseria gonorrhoeae isolates from 15 persons infected multip le times with the same serovar were compared using por gene sequencing, opa -typing, and arbitrarily primed-polymerase chain reaction. All three molecu lar techniques were more discriminatory than serotyping and identified diff erences between some isolates belonging to the same serovar. Although there were differences among For sequences within some serovars, 10 of 15 subjec ts became reinfected with gonococci expressing identical For proteins, Sequ ence analysis of por genes revealed evidence of horizontal genetic exchange and point mutations in potential surface-exposed regions during passage in the community.