title: Characterization and protective property of Brucella abortus cydC and looP mutants.
abstract: Brucella abortus readily multiplies in professional or nonprofessional phagocytes in vitro and is highly virulent in mice. Isogenic mutants of B. abortus biovar 1 strain IVKB9007 lacking the ATP/GDP-binding protein motif A (P-loop) (named looP; designated here the IVKB9007 looP::Tn5 mutant) and the ATP-binding/permease protein (cydC; designated here the IVKB9007 cydC::Tn5 mutant) were identified and characterized by transposon mutagenesis using the mini-Tn5Km2 transposon. Both mutants were found to be virtually incapable of intracellular replication in both murine macrophages (RAW264.7) and the HeLa cell line, and their virulence was significantly impaired in BALB/c mice. Respective complementation of the IVKB9007 looP::Tn5 and IVKB9007 cydC::Tn5 mutants restored their ability to survive in vitro and in vivo to a level comparable with that of the wild type. These findings indicate that the cydC and looP genes play important roles in the virulence of B. abortus. In addition, intraperitoneal immunization of mice with a dose of the live IVKB9007 looP::Tn5 and IVKB9007 cydC::Tn5 mutants provided a high degree of protection against challenge with pathogenic B. abortus strain 544. Both mutants should be evaluated further as a live attenuated vaccine against bovine brucellosis for their ability to stimulate a protective immune response.
authors.affiliation: College of Veterinary Medicine, Kangwon National University, Chuncheon, South Korea.
authors.forename: Quang Lam
authors.initials: QL
authors.lastname: Truong
authors.affiliation: College of Veterinary Medicine, Kangwon National University, Chuncheon, South Korea.
authors.forename: Youngjae
authors.initials: Y
authors.lastname: Cho
authors.affiliation: College of Veterinary Medicine, Kangwon National University, Chuncheon, South Korea.
authors.forename: Abhijit Kashinath
authors.initials: AK
authors.lastname: Barate
authors.affiliation: College of Veterinary Medicine, Gyeongsang National University, Jinju, South Korea.
authors.forename: Suk
authors.initials: S
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Kangwon National University, Chuncheon, South Korea twhahn@kangwon.ac.kr.
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Hahn
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000172:deficiency / Q000235:genetics*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D002004:Brucella Vaccine / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D002003:Brucella abortus / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D002352:Carrier Proteins / Q000235:genetics*; D002460:Cell Line; D004251:DNA Transposable Elements; D004847:Epithelial Cells / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006801:Humans; D007274:Injections, Intraperitoneal; D008264:Macrophages / Q000382:microbiology; D008807:Mice, Inbred BALB C; D016254:Mutagenesis, Insertional; D014611:Vaccination / Q000379:methods; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014774:Virulence; D037521:Virulence Factors / Q000172:deficiency / Q000235:genetics*
chemical_list: D018528:ATP-Binding Cassette Transporters; C090796:ATP-binding protein, bacteria; D001426:Bacterial Proteins; D002004:Brucella Vaccine; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D014613:Vaccines, Attenuated; D037521:Virulence Factors