title: Rapid increase in pertactin-deficient Bordetella pertussis isolates, Australia.
abstract: Acellular vaccines against Bordetella pertussis were introduced in Australia in 1997. By 2000, these vaccines had replaced whole-cell vaccines. During 2008-2012, a large outbreak of pertussis occurred. During this period, 30% (96/320) of B. pertussis isolates did not express the vaccine antigen pertactin (Prn). Multiple mechanisms of Prn inactivation were documented, including IS481 and IS1002 disruptions, a variation within a homopolymeric tract, and deletion of the prn gene. The mechanism of lack of expression of Prn in 16 (17%) isolates could not be determined at the sequence level. These findings suggest that B. pertussis not expressing Prn arose independently multiple times since 2008, rather than by expansion of a single Prn-negative clone. All but 1 isolate had ptxA1, prn2, and ptxP3, the alleles representative of currently circulating strains in Australia. This pattern is consistent with continuing evolution of B. pertussis in response to vaccine selection pressure.
authors.forename: Connie
authors.initials: C
authors.lastname: Lam
authors.forename: Sophie
authors.initials: S
authors.lastname: Octavia
authors.forename: Lawrence
authors.initials: L
authors.lastname: Ricafort
authors.forename: Vitali
authors.initials: V
authors.lastname: Sintchenko
authors.forename: Gwendolyn L
authors.initials: GL
authors.lastname: Gilbert
authors.forename: Nicholas
authors.initials: N
authors.lastname: Wood
authors.forename: Peter
authors.initials: P
authors.lastname: McIntyre
authors.forename: Helen
authors.initials: H
authors.lastname: Marshall
authors.forename: Nicole
authors.initials: N
authors.lastname: Guiso
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Keil
authors.forename: Andrew
authors.initials: A
authors.lastname: Lawrence
authors.forename: Jenny
authors.initials: J
authors.lastname: Robson
authors.forename: Geoff
authors.initials: G
authors.lastname: Hogg
authors.forename: Ruiting
authors.initials: R
authors.lastname: Lan
mesh_terms: D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D001315:Australia; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000276:immunology; D001886:Bordetella pertussis / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D037342:Pertussis Toxin / Q000235:genetics / Q000276:immunology; D010567:Pertussis Vaccine / Q000276:immunology; D010566:Virulence Factors, Bordetella / Q000235:genetics* / Q000276:immunology; D014917:Whooping Cough / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D010567:Pertussis Vaccine; D010566:Virulence Factors, Bordetella; C068929:pertactin; D037342:Pertussis Toxin
keywords: Australia; Bordetella pertussis; bacteria; evolution; genes; immunization; outbreaks; pertactin; prn gene; vaccination; vaccine; whooping cough