Construction and characterization of rtxA and rtxC mutants of auxotrophic O139 Vibrio cholerae
| Autor: | Melissa Chan, S. Kurunathan, Tan Gim Cheong, Tan ZiNing, P. Lalitha, Manickam Ravichandran, Syed A. Ali, Zainul F. Zainuddin |
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| Rok vydání: | 2009 |
| Předmět: |
Virulence Factors
Auxotrophy Mutant Bacterial Toxins medicine.disease_cause Microbiology Vibrio cholerae O139 Mice Bacterial Proteins Vibrionaceae Cell Line Tumor medicine Animals Humans Serotyping biology Toxin Cholera toxin RTX toxin Cholera Vaccines biology.organism_classification Virology Intestines Mutagenesis Insertional Infectious Diseases Vibrio cholerae Genes Bacterial Rabbits Cholera vaccine Acyltransferases Gene Deletion |
| Zdroj: | Microbial pathogenesis. 48(2) |
| ISSN: | 1096-1208 |
| Popis: | Vibrio cholerae is a Gram-negative bacterium that causes diarrheal disease. V. cholerae O1 and O139 serogroups are toxigenic and are known to cause epidemic cholera. These serogroups produce cholera toxin and other accessory toxins such as accessory cholera enterotoxin, zonula occludens toxin, and multifunctional, autoprocessing repeat in toxin (MARTX). In the present study, we incorporated mutated rtxA and rtxC genes that encode MARTX toxin into the existing aminolevulinic acid (ALA) auxotrophic vaccine candidate VCUSM2 of V. cholerae O139 serogroup. The rtxC mutant was named VCUSM9 and the rtxC/rtxA mutant was named VCUSM10. VCUSM9 and VCUSM10 were able to colonize intestinal cells well, compared with the parent vaccine strain, and produced no fluid accumulation in a rabbit ileal loop model. Cell rounding and western blotting assays indicated that mutation of the rtxC gene alone (VCUSM9 strain) did not abolish MARTX toxicity. However mutation of both the rtxA and rtxC genes (VCUSM10) completely abolished MARTX toxicity. Thus we have produced a new, less reactogenic, auxotrophic rtxC/rtxA mutated vaccine candidate against O139 V. cholerae. |
| Databáze: | OpenAIRE |
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