The Fim and FhaB adhesins play a crucial role in nasal cavity infection and Bordetella pertussis transmission in a novel mouse catarrhal infection model

PLoS Pathog. 2022 Apr 8;18(4):e1010402. doi: 10.1371/journal.ppat.1010402. eCollection 2022 Apr.

Abstract

Pulmonary infections caused by Bordetella pertussis used to be the prime cause of infant mortality in the pre-vaccine era and mouse models of pertussis pneumonia served in characterization of B. pertussis virulence mechanisms. However, the biologically most relevant catarrhal disease stage and B. pertussis transmission has not been adequately reproduced in adult mice due to limited proliferation of the human-adapted pathogen on murine nasopharyngeal mucosa. We used immunodeficient C57BL/6J MyD88 KO mice to achieve B. pertussis proliferation to human-like high counts of 108 viable bacteria per nasal cavity to elicit rhinosinusitis accompanied by robust shedding and transmission of B. pertussis bacteria to adult co-housed MyD88 KO mice. Experiments with a comprehensive set of B. pertussis mutants revealed that pertussis toxin, adenylate cyclase toxin-hemolysin, the T3SS effector BteA/BopC and several other known virulence factors were dispensable for nasal cavity infection and B. pertussis transmission in the immunocompromised MyD88 KO mice. In contrast, mutants lacking the filamentous hemagglutinin (FhaB) or fimbriae (Fim) adhesins infected the nasal cavity poorly, shed at low levels and failed to productively infect co-housed MyD88 KO or C57BL/6J mice. FhaB and fimbriae thus appear to play a critical role in B. pertussis transmission. The here-described novel murine model of B. pertussis-induced nasal catarrh opens the way to genetic dissection of host mechanisms involved in B. pertussis shedding and to validation of key bacterial transmission factors that ought to be targeted by future pertussis vaccines.

MeSH terms

  • Adenylate Cyclase Toxin
  • Adhesins, Bacterial* / metabolism
  • Animals
  • Bordetella pertussis* / genetics
  • Disease Models, Animal
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Myeloid Differentiation Factor 88
  • Nasal Cavity / microbiology
  • Pertussis Vaccine
  • Virulence Factors, Bordetella / genetics
  • Whooping Cough* / transmission

Substances

  • Adenylate Cyclase Toxin
  • Adhesins, Bacterial
  • Myeloid Differentiation Factor 88
  • Pertussis Vaccine
  • Virulence Factors, Bordetella

Grants and funding

This work was supported by the CSF Grant 19-27630X (P.S.) and by projects LM2018133 (Czech National Node to the European Infrastructure for Translational Medicine) and LM2018126 (Czech Centre for Phenogenomics) from Ministry of Education, Youth and Sports of the Czech Republic, and OP RDE CZ.02.1.01/0.0/0.0/18_046/0015861 CCP Infrastructure Upgrade II by MEYS and ESIF and OP RDE CZ.1.05/2.1.00/19.0395 a CZ.1.05/1.1.00/02.0109.The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.