title: Mutation of purD and purF genes further attenuates Brucella abortus strain RB51.
abstract: In the present study, transposon mutagenesis was used to further attenuate Brucella abortus RB51 vaccine strain. Two purD and purF mutants were constructed, characterized and evaluated for attenuation via intracellular survival in murine macrophage-like RAW264.7 and HeLa cells, and by clearance in BALB/c mice. The purD and purF mutants showed significantly decreased intracellular survival, and complementation of these mutants with intact copies of purD or purF genes of RB51 strain was able to restore these defects. In addition, the pur mutants presented significantly lowered persistence in mice. Immunization with purD and purF mutants protected mice against a challenge with the virulent B. abortus strain 544 at a level similar to that of the parent RB51. These data suggest that genes encoding the early stages of purine biosynthesis (purD and purF) are required for intracellular survival and virulence of B. abortus.
authors.affiliation: College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Quang Lam
authors.initials: QL
authors.lastname: Truong
authors.affiliation: College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Youngjae
authors.initials: Y
authors.lastname: Cho
authors.affiliation: College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Abhijit Kashinath
authors.initials: AK
authors.lastname: Barate
authors.affiliation: College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, South Korea.
authors.forename: Suk
authors.initials: S
authors.lastname: Kim
authors.affiliation: The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Masahisa
authors.initials: M
authors.lastname: Watarai
authors.affiliation: College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, South Korea. Electronic address: twhahn@kangwon.ac.kr.
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Hahn
mesh_terms: D000818:Animals; D053898:Biosynthetic Pathways / Q000235:genetics; D002003:Brucella abortus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D002006:Brucellosis / Q000382:microbiology* / Q000473:pathology; D002460:Cell Line; D004251:DNA Transposable Elements; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000382:microbiology*; D005816:Genetic Complementation Test; D008264:Macrophages / Q000382:microbiology*; D008807:Mice, Inbred BALB C; D016254:Mutagenesis, Insertional; D009154:Mutation; D011687:Purines / Q000096:biosynthesis; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D011687:Purines; D037521:Virulence Factors; C030985:purine
keywords: Brucella abortus RB51 vaccine strain; Protection; Purine biosynthesis; Transposon mutagenesis; Virulence