Project description:In marine Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome via homologous recombination. Expression of the master competence regulator TfoX bypasses the need for chitin induction and drives expression of the genes required for competence in several Vibrio species. Here, we show that TfoX expression in two Vibrio campbellii strains, DS40M4 and NBRC 15631, enables high frequencies of natural transformation. Conversely, transformation was not achieved in the model quorum-sensing strain V. campbellii BB120 (previously classified as Vibrio harveyi). Surprisingly, we find that quorum sensing is not required for transformation in V. campbellii DS40M4. This result is in contrast to Vibrio cholerae that requires the quorum-sensing regulator HapR to activate the competence regulator QstR. However, similar to V. cholerae, QstR is necessary for transformation in DS40M4. To investigate the difference in transformation frequencies between BB120 and DS40M4, we used previously studied V. cholerae competence genes to inform a comparative genomics analysis coupled with transcriptomics. BB120 encodes homologs of all known competence genes, but most of these genes were not induced by ectopic expression of TfoX, which likely accounts for the non-functional natural transformation in this strain. Comparison of transformation frequencies among Vibrio species indicates a wide disparity among even closely related strains, with Vibrio vulnificus having the lowest functional transformation frequency. We show that ectopic expression of both TfoX and QstR is sufficient to produce a significant increase in transformation frequency in Vibrio vulnificus.
Project description:Vibriosis caused by Vibrio vulnificus on eels represents an important threat for this specie under culture conditions. Development of new transcriptomic tools is essential to increase the knowledge of eel biology, that nowadays is scarcer. Therefore, using previous results obtained by 454 sequencing of the eel immune-enriched transcriptome, an eel-specific custom microarray have been designed. Gills transcriptomic pattern were analyzed as a principal portal of entry for pathogens in fish after 1h of bath infection with Vibrio vulnificus to describe gill immune response. Moreover, two different strains were used, vibro vulnificus wild type (R99) and rtx double mutant (CT285), to asses the virulence of these pathogen caused by MARTX.
Project description:VarS/A is one of the global factors regulating diverse aspects of metabolism and virulence of bacteria including pathogenic Vibrio spp. An experiment to identify VarS/A-regulon in V. vulnificus revealed that a putative LuxR-type transcriptional regulator was down-regulated in ΔvarA mutant. To investigate the roles of this regulatory cascade from VarS/A to a LuxR-type regulator in V. vulnificus, the target gene regulated by a LuxR-regulator was identified and its expression was characterized.
Project description:Two-condition experiment, Wild-type vs. smcR mutant. Biological replicates: 3 control, 3 mutant strains, independently grown and harvested. One replicate per array. A significant portion of the SmcR regulon predicted on the basis of microarray analysis results is indeed regulated by SmcR and that SmcR is a global regulator in V. vulnificus.
Project description:IscR is a novel global regulator potentially contributing to the overall success in survival and pathogenesis of V. vulnificus by coordinating the regulation of various virulence factors. The profiles of transcripts from the V. vulnificus iscR mutant and the parental wild type were compared by using a V. vulnificus whole-genome microarray. Two-condition experiment: Wild type vs. iscR mutant. Biological replicates: 3 control, 3 mutant strains, independently grown and harvested. One replicate per array. For transcriptome analysis, the V. vulnificus whole genome TwinChip, manufactured and kindly provided by the 21C Frontier Microbial Genomics and Applications Center (Daejeon, South Korea), was used.
Project description:Vibriosis caused by Vibrio vulnificus on eels represents an important threat for this specie under culture conditions. Development of new transcriptomic tools is essential to increase the knowledge of eel biology, that nowadays is scarcer. Therefore, using previous results obtained by 454 sequencing of the eel immune-enriched transcriptome, an eel-specific custom microarray have been designed. Gills transcriptomic pattern were analyzed as a principal portal of entry for pathogens in fish after 1h of bath infection with Vibrio vulnificus to describe gill immune response. Moreover, two different strains were used, vibro vulnificus wild type (R99) and rtx double mutant (CT285), to asses the virulence of these pathogen caused by MARTX. Adult european eels were bath infected with two Vibrio vulnificus strains, the wild type and double Rtx mutant (CT285). After 0, 3, 12h post-infection eel gills were sampled. Three individuals per experimental point were sampled, including a Control group and a Handling control group. Obtaining a total of 24 samples. The transcriptomic profile was described for each individual sample.
Project description:Transcriptome of Vibrio vulnificus biofilm treated and untreated with QStatin, an inhibitor of the quorum-sensing master regulator SmcR
Project description:IscR is a novel global regulator potentially contributing to the overall success in survival and pathogenesis of V. vulnificus by coordinating the regulation of various virulence factors. The profiles of transcripts from the V. vulnificus iscR mutant and the parental wild type were compared by using a V. vulnificus whole-genome microarray.
Project description:Two-condition experiment, Wild-type vs. smcR mutant. Biological replicates: 3 control, 3 mutant strains, independently grown and harvested. One replicate per array. A significant portion of the SmcR regulon predicted on the basis of microarray analysis results is indeed regulated by SmcR and that SmcR is a global regulator in V. vulnificus. For transcriptome analysis, the V. vulnificus whole genome TwinChip, manufactured and kindly provided by the 21C Frontier Microbial Genomics and Applications Center(Daejeon, South Korea), was used.