Neisseria gonorrhoeae isolates resistant to extended spectrum cephalosporins and macrolides isolated from symptomatic men in western Kenya

Abstract

Background

We characterized the antimicrobial resistance (AMR) profiles of Neisseria gonorrhoeae (NG) isolated from symptomatic men at a sexually transmitted infection clinic in Kisumu, Kenya.

Methods

Two urethral swabs were obtained from symptomatic men between 2020 and 2022, one for Gram’s stain and the other inoculated directly onto modified Thayer-Martin media containing 1% VCNT and 1% IsoVitaleX enrichment. Culture results were confirmed by colony morphology, Gram’s stain and oxidase test. Duplicate isolates were shipped to Uniformed Services University for confirmation and characterization. Susceptibility to eight drugs was assessed by E-test. Agar dilution confirmed resistance to ceftriaxone, cefixime, and azithromycin. Susceptibility, intermediate resistance (IR), and resistance (R) were determined according to published criteria.

Results

Of 154 enrolled participants, 112 were culture-positive for NG. Agar dilution results in 110 (98.2%) showed the following: azithromycin-R (1.8%), and 4.5% R or IR to ceftriaxone or cefixime: ceftriaxone-R (0.9%), ceftriaxone-IR (2.7%), and cefixime-IR (2.7%). By E-test, most isolates were IR or R to tetracycline (97.2%), penicillin (90.9%), and ciprofloxacin (95.4%).

Conclusions

We detected NG with resistance to azithromycin and ceftriaxone, indicating a growing threat to the current Kenyan dual syndromic treatment of urethritis with cephalosporin plus macrolides. Ongoing AMR surveillance is essential for effective drug choices.