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

•Surveillance of antimicrobial resistance and molecular characterisation of resistant N. gonorrhoeae in Fukuoka, Japan.•Increase in gonococci with decreased susceptibility or resistance to cefixime and ceftriaxone observed in recent years.•Four major NG-MAST STs (ST2958, ST1407, ST6798 and ST4015) with a multidrug-resistant phenotype were identified.•Of 54 isolates belonging to four major STs, 42 (77.8%) had a penA mosaic allele and 12 (22.2%) a penA non-mosaic allele. 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. 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. 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. 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.