Higher Prevalence of Multi-Drug Resistant Gonococcal Infections Among Patients with Prior Gonococcal and Chlamydia Infections

Abstract

Abstract Introduction/Objective Neisseria gonorrhoeae (NG) is the 2nd most common cause of sexually transmitted infection worldwide. WHO data from 2009-14 showed widespread resistance to ciprofloxacin (97%), azithromycin (81%), and oral cefixime and injectable ceftriaxone (66%). We have investigated local epidemiology of antimicrobial resistance in PCR-confirmed NG by chromosomal multi-locus sequence typing and analysis. Methods/Case Report Clinical specimens of 85 patients who tested positive for NG using automated PCR (COBAS 4800; Roche Diagnostics) were used in this study. The samples were amplified by PCR using 10 primers (Integrated DNA Technologies, USA) targeting seven antibiotic resistance-associated loci in the bacterial chromosome (penA, mtrR, ponA, porB, gyr, parC and 23s rRNA) and sequenced on a 48-channel ABI 3730 Sanger sequencer (Thermo Fisher). The resulting sequences were analyzed using the NG Sequence Typing for Antibiotic Resistance (NG-STAR) database for matching alleles, correlating to clinical resistance. Results were analyzed by Chi-square or Fisher’s exact tests. Results (if a Case Study enter NA) Most patients positive for NG were non-Hispanic Black males (60%), with mean age of 25 years (range: 14-53 years). 23.5% had Chlamydia trachomatis (CT) co-infection, and 29.4% had other sexually transmitted infections, such as syphilis, HIV and HPV. 15.0% had previous NG infection, and 12% had previous CT infection. Sixty-five samples (76.5%) yielded at least one gene locus with a DNA sequence with >95% similarity in the NG-STAR database. About half (50.6%) of these sample had confirmed resistance mutations, 5 of which indicated resistance to multiple antibiotics. All specimens with porB and gyr mutations were resistant to penicillins, ceftriaxone, cefixime, erythromycin, tetracycline and ciprofloxacin. Most of those with mtrR mutations were resistant to ciprofloxacin. Most of those with mutations (with or without resistance) had previous NG infection. Significant correlation was observed between those with at least 1 mutated gene locus and CT co-infection (p=0.0001). Conclusion A significant proportion of our patients tested positive for resistance mutations, a majority of whom had previous NG infection. There was significant correlation between the presence of mutations and CT co-infection. These findings warrant utilization of culture and sensitivity testing in patients with previous NG and CT co-infection.