Penicillin and Cefotaxime Resistance of Quinolone-Resistant Neisseria meningitidis Clonal Complex 4821, Shanghai, China, 1965-2020

Abstract

Clonal complex 4821 (CC4821) Neisseria meningitidis, usually resistant to quinolones but susceptible to penicillin and third-generation cephalosporins, is increasing worldwide. To characterize the penicillin-nonsusceptible (Pen^NS) meningococci, we analyzed 491 meningococci and 724 commensal Neisseria isolates in Shanghai, China, during 1965-2020. The Pen^NS proportion increased from 0.3% in 1965-1985 to 7.0% in 2005-2014 and to 33.3% in 2015-2020. Of the 26 Pen^NS meningococci, 11 (42.3%) belonged to the CC4821 cluster; all possessed mutations in penicillin-binding protein 2, mostly from commensal Neisseria. Genetic analyses and transformation identified potential donors of 6 penA alleles. Three Pen^NS meningococci were resistant to cefotaxime, 2 within the CC4821 cluster. With 96% of the Pen^NS meningococci beyond the coverage of scheduled vaccination and the cefotaxime-resistant isolates all from toddlers, quinolone-resistant CC4821 has acquired penicillin and cefotaxime resistance closely related to the internationally disseminated ceftriaxone-resistant gonococcal FC428 clone, posing a greater threat especially to young children.

Keywords: CC4821; China; Neisseria meningitidis; Shanghai; antimicrobial resistance; bacteria; clonal complex 4821; horizontal gene transfer; multidrug resistance; penicillin; third-generation cephalosporins.

Figure 1

Percentage of meningococcal isolates with penicillin nonsusceptibility and MIC₅₀ values, Shanghai, China, 1965–2020. MIC₅₀, minimum inhibitory concentrations at which 50% of the tested isolates are inhibited.

Figure 2

Allele-based clusters of penicillin-nonsusceptible meningococcal isolates identified by using Neisseria meningitidis core-genome multilocus sequence typing (MLST) v1.0 scheme, Shanghai, China, 1965–2020. Arrows indicated the 3 singleton isolates identified by 7-locus–based MLST but assigned to CC4821 cluster by core-genome MLST analysis. Scale bar indicates numbers of loci. CC, clonal complex; IMD, invasive meningococcal disease; NG, nongroupable; NmB, serogroup B; NmC, serogroup C; NmW, serogroup W; NmY, serogroup Y; ST, sequence type.

Figure 3

Phylogenetic analysis of penA alleles of Neisseria isolates and genomes, Shanghai, China, 1965–2020, and reference isolates. Phylogenetic analysis of the nucleotide sequences of 580 penA alleles (nucleotides 1321–1722) from N. meningitidis (n = 21,582), N. gonorrhoeae (n = 7,605), N. lactamica (n = 683), N. subflava (n = 431), N. cinerea (n = 65) , N. polysaccharea (n = 52), N. mucosa (n = 33), and other commensal Neisseria (n = 73) isolates and genomes collected in this study and from the Neisseria PubMLST database was constructed by using IQ-TREE version 2.2.0 (23), with both SH-aLRT test and UFboot set as 1,000. The values of SH-aLRT and ultrafast bootstrap (Ufboot) are shown on the node of each clade as SH-aLRT/Ufboot. Clusters were determined by using SH-aLRT values of 80% from the SH-aLRT tests with 1,000 replicates and ultrafast bootstrap (UFBoot) values of 85% from bootstrap tests with 1,000 replicates (IQ-TREE). Alleles penA378, penA405, penA552, penA553, penA843, penA868, and penA917 were within in the N. lactamica cluster; penA662, penA777, and penA865 were within the N. subflava cluster; penA379 was within the N. gonorrhoeae cluster; and the other 8 penA alleles were located outside the 5 clusters. Scale bar indicates substitutions per site. Pen^NS, penicillin-nonsusceptible meningococci.