Macrolide susceptibility and molecular characteristics of Bordetella pertussis

Juansheng Zhang1, Diqiang Zhang2, Xiaoqiang Wang1

  • 1Microbiology laboratory, Xi'an Centre for Disease Control and Prevention, Xi'an, Shaanxi Province, China.

Abstract

Insights

Macrolide resistance is prevalent in Bordetella pertussis clinical isolates from western China. Specific molecular types correlate with macrolide resistance, suggesting potential links between genotype and antibiotic susceptibility.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Whooping cough (pertussis) is a significant public health concern.
  • Macrolide antibiotics are a primary treatment for pertussis.
  • Emerging antibiotic resistance threatens treatment efficacy.

Purpose of the Study:

  • To investigate macrolide resistance in Bordetella pertussis clinical isolates from western China.
  • To characterize the molecular features of these isolates.
  • To explore the association between macrolide resistance and specific genotypes.

Main Methods:

  • E-test was used to determine macrolide susceptibility (erythromycin, azithromycin, clarithromycin).
  • Sequencing identified the 23S rRNA gene A2047G mutation.
  • Multilocus antigen sequence typing, MLVA, and PFGE were employed for strain typing.

Main Results:

  • 46 out of 58 Bordetella pertussis strains exhibited macrolide resistance.
  • All resistant strains possessed the A2047G mutation and a specific genotype (prn1/ptxP1/ptxA1/fim3-1/fim2-1).
  • Macrolide-sensitive strains lacked the mutation and displayed distinct genotypes and MLVA types.

Conclusions:

  • Bordetella pertussis isolates in western China show high levels of macrolide resistance.
  • Distinct molecular genotypes differentiate macrolide-resistant and sensitive strains.
  • A correlation may exist between macrolide resistance acquisition and specific molecular types.