Antimicrobial resistance and molecular characterisation of Neisseria gonorrhoeae isolates in Fukuoka, Japan, 1996–2016

Abstract Objectives Antimicrobial resistance and molecular characteristics of Neisseria gonorrhoeae isolates obtained from 1996–2005 ( n  = 200) and 2008–2016 ( n  = 200) in Fukuoka, Japan, were examined. Methods MICs were determined by agar dilution. Sequence types (STs) were examined using N. gonorrhoeae multiantigen sequence typing (NG-MAST). Sequencing of major extended-spectrum cephalosporin (ESC) resistance determinants ( penA , mtrR and ponA ) was performed. Results Increases in the proportion of gonococci with decreased susceptibility or resistance to cefixime (from 18.0% in 1996–2005 to 46.0% in 2008–2016) and ceftriaxone (from 2.5% to 4.0%) were observed. Gonococcal isolates also showed increased resistance to ciprofloxacin and azithromycin. The four most prevalent NG-MAST STs with a multidrug-resistant phenotype were ST2958 ( n  = 18), ST1407 ( n  = 14), ST6798 ( n  = 12) and ST4015 ( n  = 10). The number of isolates belonging to these four STs rose between the first and second period. Among the 54 isolates belonging to the four major STs, 42 (77.8%) contained a penA mosaic allele and 12 (22.2%) contained a penA non-mosaic allele. The sequence pattern types in the 42 isolates with a penA mosaic allele included type X (64.3%), type XXXIV (33.3%) and a novel pattern type (2.4%). In contrast, all 12 isolates with the penA non-mosaic allele included the sequence pattern type V. Conclusion Neisseria gonorrhoeae isolates with decreased susceptibility or resistance to ESC have increased over the years. Four major STs with a multidrug-resistant phenotype were identified. These isolates contained a penA mosaic allele or a non-mosaic allele.