Cooperative Recognition of Internationally Disseminated Ceftriaxone-Resistant Neisseria gonorrhoeae Strain

Abstract

Ceftriaxone remains a first-line treatment for patients infected by Neisseria gonorrhoeae in most settings. We investigated the possible spread of a ceftriaxone-resistant FC428 N. gonorrhoeae clone in Japan after recent isolation of similar strains in Denmark (GK124) and Canada (47707). We report 2 instances of the FC428 clone in Australia in heterosexual men traveling from Asia. Our bioinformatic analyses included core single-nucleotide variation phylogeny and in silico molecular typing; phylogenetic analysis showed close genetic relatedness among all 5 isolates. Results showed multilocus sequence type 1903; N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) 233; and harboring of mosaic penA allele encoding alterations A311V and T483S (penA-60.001), associated with ceftriaxone resistance. Our results provide further evidence of international transmission of ceftriaxone-resistant N. gonorrhoeae. We recommend increasing awareness of international spread of this drug-resistant strain, strengthening surveillance to include identifying treatment failures and contacts, and strengthening international sharing of data.

Keywords: Australia; Canada; China; France; Japan; Neisseria gonorrhoeae; Spain; antimicrobial resistance; azithromycin; cefixime; ceftriaxone; cephalosporin; ciprofloxacin; gentamycin; gonorrhea; penA gene; penicillin; penicillinase; spectinomycin; tetracycline; β-lactam.

Figure

Core single-nucleotide variation (SNV) phylogenetic tree of ceftriaxone-resistant Neisseria gonorrhoeae isolates. The maximum-likelihood phylogenetic tree is rooted on the reference genome of N. gonorrhoeae FA1090 (GenBank accession no. NC_002946.2). Isolates are indicated by country and year. Strains F89, A8806, and H041 (World Health Organization [WHO] reference panel WHO-Y, WHO-Z, and WHO-X, respectively) are previously reported ceftriaxone-resistant reference strains (10). Scale bar indicates estimated evolutionary divergence between isolates on the basis of average genetic distance between strains (estimated number of substitutions in the sample/total number of high-quality SNVs). MLST, multilocus sequence type; NG-MAST, Neisseria gonorrhoeae multiantigen sequence type; NG-STAR, Neisseria gonorrhoeae sequence type for antimicrobial resistance; PenA, penicillin-binding protein 2.