title: Protection against experimental melioidosis following immunization with live Burkholderia thailandensis expressing a manno-heptose capsule.
abstract: Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei. It is highly resistant to antibiotic treatment, and there is currently no licensed vaccine. Burkholderia thailandensis is a close relative of Burkholderia pseudomallei but is essentially avirulent in mammals. In this report, we detail the protective efficacy of immunization with live B. thailandensis E555, a strain which has been shown to express an antigenic capsule similar to that of B. pseudomallei. Immunization with E555 induced significant protection against a lethal intraperitoneal B. pseudomallei challenge in a mouse model of infection, with no mice succumbing to infection over the course of the study, even with challenges of up to 6,000 median lethal doses. By comparison, mice immunized with B. thailandensis not expressing a B. pseudomallei-like capsule had significantly decreased levels of protection. E555-immunized mice had significantly higher levels of IgG than mice immunized with noncapsulated B. thailandensis, and these antibody responses were primarily directed against the capsule.
authors.affiliation: Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom. aescott2@dstl.gov.uk
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Scott
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Laws
authors.forename: Riccardo V
authors.initials: RV
authors.lastname: D'Elia
authors.forename: Margaret G M
authors.initials: MG
authors.lastname: Stokes
authors.forename: Tannistha
authors.initials: T
authors.lastname: Nandi
authors.forename: E Diane
authors.initials: ED
authors.lastname: Williamson
authors.forename: Patrick
authors.initials: P
authors.lastname: Tan
authors.forename: Joann L
authors.initials: JL
authors.lastname: Prior
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Atkins
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000276:immunology / Q000378:metabolism; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D019117:Burkholderia / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008554:Melioidosis / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D016019:Survival Analysis; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated