title: Construction and characterization of an unmarked aroC deletion mutant of Burkholderia pseudomallei strain A2.
abstract: Using a sucrose counter-selection strategy, we have constructed an unmarked aroC deletion mutant of B. pseudomallei strain A2 in order to investigate the possibility of an effective live-attenuated vaccine. The aroC deletion in the resultant mutant, designated A2DeltaaroC, was confirmed by PCR, Southern hybridization and failure of the mutant to grow in a defined medium without aromatic compounds. Compared to the parental wild type strain, A2DeltaaroC was highly attenuated for virulence following intraperitoneal introduction into BALB/c and C57BL/6 mice. BALB/c mice immunized intraperitoneally with A2DeltaaroC were not protected against a challenge dose of 500 cfu (25 x LD50) of the parental strain A2, whereas C57BL/6 mice similarly immunized intraperitoneally with A2DeltaaroC were significantly protected against a challenge dose of 6,000 cfu (20 x LD50).
authors.affiliation: Department of Clinical Immunology, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Thitima
authors.initials: T
authors.lastname: Srilunchang
authors.forename: Tanakorn
authors.initials: T
authors.lastname: Proungvitaya
authors.forename: Surasak
authors.initials: S
authors.lastname: Wongratanacheewin
authors.forename: Richard
authors.initials: R
authors.lastname: Strugnell
authors.forename: Preecha
authors.initials: P
authors.lastname: Homchampa