Journal of Clinical Pediatrics ›› 2025, Vol. 43 ›› Issue (8): 575-582.doi: 10.12372/jcp.2025.25e0425

• Original Article • Previous Articles     Next Articles

Antigenic genotypic characteristics and antibiotic resistance analysis of Bordetella pertussis in two regions of Fujian province

SHI Xiaosong1, FU Shijie2, HE Xiaohua1, LYU Hui3, CHEN Houyang2, CHEN Maolin4, CHEN Jie1()   

  1. 1. Department of Pediatrics, Fuzhou University Affiliated Provincial Hospital, Provincial Clinical Medical College Of Fujian Medical University, Fuzhou 350001, Fujian, China
    2. Department of Pediatrics, Youxi County General Hospital, Youxi 365100, Fujian, China
    3. Department of Laboratory Medicine, Fuzhou University Affiliated Provincial Hospital, Provincial Clinical Medical College Of Fujian Medical University, Fuzhou 350001, Fujian, China
    4. Department of Laboratory Medicine, Youxi County General Hospital, Youxi 365100, Fujian, China
  • Received:2025-04-21 Accepted:2025-06-18 Published:2025-08-15 Online:2025-07-28
  • Contact: CHEN Jie E-mail:sy1017@fzu.edu.cn

Abstract:

Objective To analyze the genetic polymorphism of antigenic genes and antimicrobial resistance phenotypes of Bordetella pertussis (BP) in Fuzhou and Youxi, Fujian Province, China, and to provide scientific evidence for optimizing vaccination strategies and antibiotic use. Methods A total of 336 nasopharyngeal swab specimens from suspected pertussis cases were collected from both regions in 2024. Bacterial culture, isolation, and identification were performed. Polymorphism and mutations were determined by analyzing seven antigenic genes (ptxP, ptxA, ptxC, prn, fim3, fim2, tcfA) and the 23S rRNA A2047 locus. A maximum-likelihood phylogenetic tree was constructed based on core-genome single nucleotide polymorphisms (cgSNPs). The minimum inhibitory concentrations (MICs) of macrolides, sulfonamides, and β-lactams were determined using the E-test method. Results Twenty-nine BP clinical isolates were successfully obtained (8.6%, 29/336). Antigenic gene profiling revealed that the predominant genotype was ptxP3/prn2/ptxC1/ptxA1/fim2-1/fim3-1/tcfA2 (55.2%, 16/29), with ptxP3/prn2/ptxA1 strains accounting for 72.4% (21/29). Four prn150 mutant strains were identified (13.8%, 4/29). Phylogenetic analysis demonstrated that the vaccine strain CS formed an independent evolutionary branch (Cluster A). The 2024 Fujian isolates exhibited significant genetic divergence from pre-2020 domestic strains, forming two major clusters: Cluster B (ptxP3/prn2/ptxA1, containing most Fujian isolates) and Cluster C (ptxP1/prn1/ptxA1, comprising historical isolates). The 23S rRNA A2047G mutation conferring macrolide resistance was detected in all isolates, with MICs > 90 mg/L. MICs for TMP-SMX ranged from 0.005 to 0.45 mg/L. MICs for β-lactams (ceftriaxone, cefotaxime, cefoperazone/sulbactam) ranged from 0.004 to 0.64 mg/L. Conclusion The epidemic strains of BP circulating in Fujian exhibit distinct antigenic gene evolutionary patterns and widespread macrolide resistance. These findings highlight the urgent need to strengthen molecular genotyping-based surveillance of vaccine components and optimize antimicrobial therapy based on susceptibility profiles.

Key words: pertussis, Bordetella pertussis, antigenic genotype, whole-genome sequencing, macrolide resistance, child

CLC Number: 

  • R72