A comparative genomic snapshot of two sporadic urogenital Neisseria meningitidis isolates from Meizhou, China

Objectives To characterize the genomic profiles of sporadic urogenital Neisseria meningitidis isolates and expand the limited data on this emerging infection. Methods Comparative genomic analysis was performed to investigate the diversity and clonal relationships of urogenital Neisseria meningitidis isolates in Meizhou, China. Two sporadic isolates, designated MZ01 and MZ02, were recovered from urethral secretions of male patients with urethral infection in 2022. These isolates were subjected to whole-genome sequencing alongside publicly available genomes from the PubMLST database. Sequence types were determined by multilocus sequence typing. Minimum spanning tree, core-genome single nucleotide polymorphism (cgSNP), and norB-aniA comparative analyses were conducted to characterize lineage-specific genetic features. Results The isolates belonged to distinct sequence types (ST-5881 for MZ01 and ST-11026 for MZ02). cgSNP analysis showed MZ01 to be highly divergent from all public genomes and MZ02 closely related to NML2024-119 and the Chinese urogenital isolate Nm521, suggesting distinct clonal origins. MZ01 harbored a serogroup B capsule synthesis locus, whereas MZ02 had a ctrA/ctrB deletion, suggesting a capsule-null genotype. Both carried meningococcus-type norB-aniA profiles distinct from the gonococcal-type cassette of US_NmUC. Both isolates showed penicillin resistance and ceftriaxone susceptibility, with MZ02 additionally resistant to ciprofloxacin and trimethoprim-sulfamethoxazole, consistent with gyrA and folP mutations. Conclusions This study provides a limited but informative genomic snapshot of sporadic urogenital Neisseria meningitidis isolates from Meizhou, China. Although based on only two isolates with limited clinical metadata, the distinct lineages observed underscore the need for continued surveillance.