(P70-LB) Extended-spectrum ß-lactamase and macrolide resistance in Neisseria gonorrhoeae in western Kenya

Background: We evaluated antimicrobial resistance in Neisseria gonorrhoeae (NG) isolated from men presenting with urethral discharge or dysuria at an STI clinic in Kisumu, Kenya.

Methods: Urethral specimens were cultured for NG. Demographic and clinical data were abstracted from medical charts. Etest assessed susceptibility: Ciprofloxacin (CIP): (Sensitive) ≤0.06, (Intermediate) 0.12–0.5, (Resistant) ≥1; ceftriaxone (CTX): (S) ≤ 0.25, (R) > 0.25: spectinomycin (SPEC): (S) ≤ 32, (I); 64, R ≥ 128; cefixime (CFX): (S) ≤0.25, (R) >0.25; azithromycin (AZT): (S) ≤1, (R) >1; penicillin (PEN): (S) ≤0.06, (I) 0.12-1, (R) ≥2; tetracycline (TET): (S) ≤0.25, (I) 0.12-1, (R) ≥2; gentamicin (GEN): (S) <8, (I) 16-32, (R) >32. Agar dilution confirmed resistance to CTX, CFX, and AZI.

Results: February 4, 2020 -January 26, 2022, 154 urethral swabs were obtained from 149 men, with 110 confirmed NG isolates. Men with NG were median age 25.5 years, 6.7% HIV infected, 73% circumcised, 95% reporting dysuria, and 95% with urethral discharge on exam. Resistance was: 93% TET, 73% PEN, 82% CIP, 1.8% AZI, 1.8% CFX, 0.9% CTX, 0% GEN, 0% SPEC. Confirmatory MICs by agar dilution were: CTX - three isolates with 0.125 mg/L and one with 0.25 mg/L; CFX - three isolates with 0.125 mg/L; AZI – five isolates with 2 mg/L and two isolates with >16 mg/L. Based on agar dilution, one isolate was CTX-R, CFX-R, and AZI-R. There were positive Spearman correlations (>0.20, p< 0.05) of eTest MIC values between: penicillin and tetracycline (0.21), tetracycline and ciprofloxacin (0.23), tetracycline and spectinomycin (0.40), tetracycline and azithromycin (0.20), ciprofloxacin and gentamicin (0.36), spectinomycin and gentamicin (0.62), and azithromycin and gentamicin (0.34). Cefixime MICs were inversely correlated with gentamicin (-0.26) and spectinomycin (-0.31). CIP-R was increased among those reporting recent new sex partners (93.3% vs. 77.5% no new partner, p=0.06); MICs for multiple drug classes varied by year of study.

Discussion: MDR and MICs of multiple drug classes was increased compared to prior surveillance. High prevalence of resistance and positive correlations among multiple drug classes reflect selective pressure and shared resistance mechanisms. Amid emerging MDR-NG, antimicrobial resistance surveillance is essential for effective drug choice.