High rate of fluoroquinolone resistant Neisseria gonorrhoeae detected by molecular surveillance of antimicrobial resistance determinants in Bulgaria

Abstract Antimicrobial-resistant Neisseria gonorrhoeae is a major public health concern. The surveillance of antimicrobial resistance benefits from rapid and accurate molecular techniques in molecular diagnostics to facilitate individualised medicine and antimicrobial stewardship. To support the recommendations for empirical treatment of gonococcal infections in Bulgaria, we investigated N. gonorrhoeae-positive clinical specimens from 2018 to 2021 for the presence of genetic determinants associated with antimicrobial resistance. N. gonorrhoeae-positive samples stored at the National Center of Infectious and Parasitic Diseases during the four-year study period were retrospectively analysed by polymerase chain reaction and DNA sequencing assays for resistance determinants to fluoroquinolones, third-generation cephalosporins and macrolides. The detected determinants indicated a high rate of fluoroquinolone resistance (59%), very low level of decreased susceptibility to third-generation cephalosporins (3%) but no macrolide resistance (0%). These findings validate the utilisation of the international guidelines’ recommendations for empirical dual therapy with ceftriaxone/cefixime and azithromycin in Bulgaria. Because of the high fluoroquinolone resistance rate, ciprofloxacin should only be considered as treatment if phenotypic or molecular antimicrobial susceptibility data indicate susceptibility to ciprofloxacin. For the purposes of surveillance and individualised medicine, molecular assays for resistance determinants could complement culture-based phenotypic gonococcal antimicrobial resistance testing.