Evaluation of predominant neisseria gonorrhoeae strain types and its correlation with fluoroquinolone resistance in Pakistan

Objective: To study the predominant Neisseria gonorrhoeae strain types in Pakistan and to evaluate their correlation with fluoroquinolone resistance.Method: A total of 314 strains were collected from 2007-2009. Of these 112 strains were randomly selected for serotyping via the coagglutination technique. Fluoroquinolone susceptibility was checked through the E-test method. Chi square was performed to assess the correlation between the strain type and fluoroquinolone resistance pattern.Results: N. gonorrhoeae isolates were typed in two serogroups and 28 serovars. Serogroup WI comprised 40% (n=45) whereas WII/WIII was 60% (n=67). Most commonly isolated serovar belonged to serogroup WI namely Aorst (10%). The other predominant circulating serovars of the serogroup WI were Aost (9%) and Ast (8%) and Bsy (8%), Bopyt (5%) and Bprt (4.5%) in the serogroup WII/III. Fluoroquinolone resistance was 98%, with an MIC of 2μg/mL in 47%, 4μg/mL in 36% and >32μg/mL in 12% of the isolates. On inferential analysis no significant correlation was observed between fluoroquinolone resistance and any particular serovars. Conclusion: A diverse population of N. gonorrhoeae serovars suggesting influx of a variety of gonococcal strains with high fluoroquinolone resistance was identified. This resistance was not associated with any particular serovars, so we speculated inappropriate use of fluoroquinolones in the community to be a major cause. Injudicious fluoroquinolone use in the community should be strongly discouraged to curtail increase in antimicrobial resistance. Furthermore, continuous surveillance of prevalent serovars will be critical to assess genetic alterations of endemic and imported strains to design effective disease control measures.