P424 Rapidly rising epidemic of African plasmid/blaTEM-1 in penicillinase-producing Neisseria gonorrhoeae from Guangdong, China

Background Our previous study showed a recent increase in the incidence of African-type penicillinase-producing Neisseria gonorrhoeae (PPNG) in Guangdong, China. The aim of this study was to investigate the prevalence and molecular epidemiology of African plasmid in PPNG isolates in Guangdong in two time frames, 2013–2015 and 2018–2019. Methods A total of 864 isolates were collected in two cities in Guangdong. Minimum inhibitory concentrations (MICs) of seven antimicrobials were determined by the agar dilution method. The molecular epidemiological characteristics were determined by PPNG and tetracycline-resistant N. gonorrhoeae (TRNG) plasmids typing, Sanger sequencing of TEM β-lactamase (blaTEM) genes,NG_porB gene and N. gonorrhoeae multiantigen sequence typing (NG-MAST). Results Investigation by PCR showed that 31.02% (268/864) of the isolates were PPNG, of which 53.36% (143/268) contained the TRNG plasmid. The blaTEM genes of PPNG isolates were carried by African increased (18.42% to 66.67%), Asian decreased (81.58% to 28.89%), and Toronto/Rio increased (0 to 4%) plasmids. Further plasmid typing showed that PPNG isolates consisted of three major clusters, namely African plasmid/blaTEM-1 (128/268, 47.76%), Asian plasmid/blaTEM-135?(59/268, 22.01%), and Asian plasmid/blaTEM-1 (57/268,21.27%). The percentage of isolates with the blaTEM-1-carrying African plasmid as predominant plasmid increased significantly from 13.16%(5/38) in 2013 to 66.67%(60/90) in 2019. Among the isolates carrying the African plasmid possessing blaTEM-1, NG-MAST_sequence type (ST)5061, ST1927, ST17748 and NG_porB type 8, 13,11,12 were found to be the predominant STs in both periods, respectively, but which showed differences in two cities in two periods. Conclusions The proportion of African plasmid/blaTEM-1 PPNG has continuously increased since 2013, in association with clonal spread, which might contribute to the rising gonorrhoea epidemic in Guangdong. The possibility that African plasmid/blaTEM-1 was acquired requires careful follow-up and continuous monitoring of African plasmid/blaTEM-1 to ascertain whether it constitutes a step towards evolutionary change.