Molecular Screening for Neisseria gonorrhoeae Antimicrobial Resistance Makers in Nigerian Men who have Sex with Men and Transgender Women

Antimicrobial resistant Neisseria gonorrhoeae (NG) is a global public health issue that threatens the effectiveness of current treatments of gonorrheal infection. Increased use of nucleic acid amplification tests (NAAT) in lieu of cultures for the detection of NG makes obtaining clinical isolates for susceptibility testing difficult, samples collected in commercial transport buffer for NAAT testing typically do not preserve viable organism. Molecular methods of assessing antibiotic susceptibility do not require viable organisms and are more rapid than traditional methods. We evaluated 243 NG positive samples in Aptima transport samples including oral swabs, rectal swabs, and urine from a cohort of Nigerian men who have sex with men (MSM) for resistance markers to penicillinase producing NG (PPNG), ciprofloxacin ( GyrA and ParC mutations) and extended spectrum cephalosporins (ESCs, PenA (mosaic allele X), PonA, mtrR, PorB mutations) by real-time PCR. NG DNA was recovered in 75% (183/243) of Aptima transport samples. Of these, 93% (171/183) were positive for at least one resistance marker. We observed a prevalence of dual resistance markers to penicillin and ciprofloxacin at 46.2% (79/171), for PPNG only at 27% (47/171) and ciprofloxacin only at 20% (35/171). Six percent of samples (10/171) tested positive for the PenA mosaic (allele X) ESC marker. Of those, ten percent (1/10) samples were positive for penicillin, ciprofloxacin and ESC resistance markers. All samples testing positive for the PenA mosaic underwent additional ESC marker testing for PonA , mtrR and PorB mutations. These data indicate that antibiotic resistant NG organisms are common in Nigeria. Laboratory and clinical capacity building in Nigeria should include development of methods to culture and identify NG and determine antimicrobial susceptibility.