Related Experiment Video
Updated: Mar 18, 2026
Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice
Published on: February 22, 2019
Better colonisation of newly emerged Bordetella pertussis in the co-infection mouse model study
Azadeh Safarchi1, Sophie Octavia1, Laurence Don Wai Luu1
1School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
Abstract:
Molecular epidemiological data indicates that the resurgence of pertussis (whooping cough) in populations with high vaccine coverage is associated with genomic adaptation of Bordetella pertussis, the causative agent of the disease, to vaccine selection pressure. We have previously shown that in the period after the introduction of acellular pertussis vaccine (ACV), the majority of circulating strains in Australia switched to single nucleotide polymorphism (SNP) cluster I (carrying ptxP3/prn2), replacing SNP cluster II (carrying ptxP1/prn3). In this study, we carried out an in vivo competition assay using a mouse model infected with SNP cluster I and II B. pertussis strains from Australia. We found that the SNP cluster I strain colonised better than the SNP cluster II strain, in both naïve and immunised mice, suggesting that SNP cluster I strains had better fitness regardless of immunisation status of the host, consistent with SNP cluster I strains replacing SNP cluster II. Nevertheless, we found that ACV enhanced clearance of both SNP cluster I and II strains from the mouse respiratory tract.
Insights
Genomic adaptation in Bordetella pertussis strains drives pertussis resurgence. Acellular pertussis vaccine (ACV) enhances clearance of both adapted and non-adapted strains, but doesn't prevent initial colonization.
Area of Science:
- * Molecular epidemiology
- * Bacteriology
- * Vaccinology
Background:
- * Pertussis (whooping cough) resurgence observed in highly vaccinated populations.
- * Genomic adaptation of *Bordetella pertussis* to vaccine selection pressure is implicated.
- * Shift from SNP cluster II (*ptxP1/prn3*) to SNP cluster I (*ptxP3/prn2*) strains observed in Australia post-acellular pertussis vaccine (ACV) introduction.
Purpose of the Study:
- * To investigate the in vivo fitness of *B. pertussis* SNP cluster I versus SNP cluster II strains.
- * To assess the impact of host immunization status on strain competition.
- * To evaluate the effect of ACV on bacterial clearance.
Main Methods:
- * In vivo competition assay using a mouse model.
- * Infection with Australian SNP cluster I and II *B. pertussis* strains.
- * Comparison of colonization in naïve and ACV-immunised mice.
Main Results:
- * SNP cluster I strains demonstrated superior colonization compared to SNP cluster II strains in both naïve and immunised mice.
- * This suggests higher intrinsic fitness of SNP cluster I strains, irrespective of host immunity.
- * ACV administration significantly enhanced the clearance of both SNP cluster I and II strains from the mouse respiratory tract.
Conclusions:
- * The increased fitness of SNP cluster I *B. pertussis* strains contributes to their dominance and pertussis resurgence.
- * While ACV aids in bacterial clearance, it may not fully prevent colonization by fitter strains.
- * Further research into vaccine strategies to counter genomic adaptation in *B. pertussis* is warranted.
More Related Videos
12:21A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness
Published on: September 28, 2022
07:43A Non-invasive and Technically Non-intensive Method for Induction and Phenotyping of Experimental Bacterial Pneumonia in Mice
Published on: September 28, 2016