title: Construction and characterization of a Vibrio cholerae serogroup O139 vaccine candidate by genetic engineering.
abstract: The present study aimed to construct and evaluate the live attenuated Vibrio cholerae serogroup O139 vaccine candidate, in which genes encoding protective antigens were integrated into the chromosomal DNA. Using the initial strain, O139-ZJ9693, the toxin-linked cryptic (TLC) and cholera toxin (CTX) genetic elements and repeats in the toxin (RTX) gene cluster were deleted from its chromosomal DNA, and the cholera toxin genes, ctxB and rstR, were transferred into the chromosome to construct the candidate vaccine strain. The expression of ctxB and the vaccine virulence were then examined. Polymerase chain reaction (PCR), enzymatic digestion and electrophoresis were performed to confirm that TLC, CTX and RTX were deleted, and that ctxB and rstR were transferred into the vaccine candidate DNA. According to the preliminary evaluation, the ctxB gene exhibited cholera toxin subunit B expression, and no enterotoxigenic or cytotoxic effects were observed in this strain. In conclusion, a recombinant strain containing genes encoding protective antigens that replaced virulence-associated genes was successfully constructed in the present study; this candidate strain may have the potential to be utilized to further evaluate the immune response.
authors.affiliation: Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Cancan
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: The Priority Laboratory of Medical Molecular Bacteriology of the Ministry of Health, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P.R. China.
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.affiliation: Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Yongyu
authors.initials: Y
authors.lastname: Rui
mesh_terms: D000818:Animals; D002771:Cholera / Q000276:immunology / Q000473:pathology / Q000517:prevention & control; D002772:Cholera Toxin / Q000235:genetics / Q000276:immunology; D022121:Cholera Vaccines / Q000235:genetics* / Q000276:immunology* / Q000633:toxicity; D015870:Gene Expression; D005818:Genetic Engineering; D005822:Genetic Vectors / Q000235:genetics; D007082:Ileum / Q000473:pathology; D011817:Rabbits; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology / Q000633:toxicity; D041242:Vibrio cholerae O139 / Q000235:genetics* / Q000276:immunology*
chemical_list: D022121:Cholera Vaccines; D019444:Vaccines, DNA; D002772:Cholera Toxin