Escalating Antimicrobial Resistance in Neisseria gonorrhoeae Over Four Years: Impressions of a National Reference Laboratory

Background and aims: Neisseria gonorrhoeae is a major global public health concern due to its rapid development of resistance to nearly all antibiotics used in its treatment.In India, limited diagnostic capacity and widespread use of syndromic management may contribute to under-recognition of antimicrobial resistance (AMR) patterns.This study aimed to assess year-wise trends in antimicrobial susceptibility of N. gonorrhoeae isolates from 2021 to 2024 to four antibiotics-penicillin, tetracycline, ciprofloxacin, and azithromycin-at a national reference sexually transmitted infections (STI) laboratory.Methods: This cross-sectional study analyzed 146 N. gonorrhoeae isolates collected from urethral/endocervical/oro-pharyngeal/anorectal swabs between January 2021 and December 2024.Isolates were identified using standard microbiological and biochemical methods.Antimicrobial susceptibility testing (AST) was performed using E-test strips on gonococcal agar base, and minimum inhibitory concentrations (MICs) were interpreted according to WHO breakpoints.Results: Overall resistance rates were high for penicillin (56.8%) and ciprofloxacin (94.5%).Penicillin resistance increased from 51.7 to 75% over the study period, with complete loss of sensitivity by 2024.Tetracycline resistance rose from 17.2% in 2021 to 54% in 2024.Ciprofloxacin resistance remained consistently above 90%, with 100% resistance observed in 2021 and 2024.Azithromycin resistance fluctuated, peaking at 17.5% in 2022 and 2024, with overall resistance at 13%.Seven isolates demonstrated high-level azithromycin resistance (MIC 256 g/mL).Conclusion: A marked upward trend in resistance to penicillin and tetracycline was observed, with ciprofloxacin continuing to be ineffective.The emergence of high-level azithromycin resistance is particularly concerning.Clinical significance: This study highlights the urgent need for ongoing AMR surveillance in N. gonorrhoeae, especially in low-and middleincome countries like India.Rising resistance to multiple antibiotics threatens current treatment protocols and underscores the importance of adopting evidence-based antimicrobial stewardship and updating treatment guidelines accordingly.