Pertactin negative Bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model.

Abstract

Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naïve (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans.

• Authors: Azadeh Safarchi, Sophie Octavia, Laurence Don Wai Luu, Chin Yen Tay, Vitali Sintchenko, Nicholas Wood, Helen Marshall, Peter McIntyre, Ruiting Lan
• Journal: Vaccine (Vaccine) Vol. 33 Issue 46 Pg. 6277-81 (Nov 17 2015) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 26432908 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical References

• Bacterial Outer Membrane Proteins
• Pertussis Vaccine
• Virulence Factors, Bordetella
• pertactin

Topics

• Animals
• Australia
• Bacterial Outer Membrane Proteins (genetics, immunology)
• Bordetella pertussis (growth & development, immunology, isolation & purification)
• Coinfection (immunology, microbiology, prevention & control)
• Disease Models, Animal
• Female
• Humans
• Mice, Inbred BALB C
• Pertussis Vaccine (administration & dosage, immunology)
• Selection, Genetic
• Virulence Factors, Bordetella (genetics, immunology)
• Whooping Cough (immunology, microbiology, prevention & control)