Project description:Transcriptional profiling of low-iron stimulon and XibR influenced regulon using wild-type Xcc 8004 and xibR mutant grown under iron-replete and iron-deplete conditions. Trancriptional analysis under iron-deplete condition, mimicking in planta environment, provides greater insights into expression pattern of several virulence-associated functions under low-iron. A genetic screen sggested the involvement of XibR (Xanthomonas iron binding regulator) in iron-uptake and metabolism. Present transcriptional analysis suggested the co-regulation of virulence associated functions including siderophore biosynthesis, motility, chemotaxis and typeIII effectors by a novel transcriptional regulator of NtrC family protein XibR and iron avability.
Project description:Vibrio vulnificus multiply rapidly in host tissues under iron overloaded conditions. To understand the effects of iron in the physiology of this pathogen we performed a genome-wide transcriptional analysis of this bacterium growing under three different iron concentrations. V.vulnificus CMCP6 cells were grown under three different iron concentrations (TSBS + EDDA 50uM, TSBS and TSBS + FAC 250 ug/ml) and samples taken at log phase. Keywords: Response to the iron concentration of the media
Project description:Previous studies have demonstrated that the iron content in marine heterotrophic bacteria is comparatively higher than that of phytoplankton. Therefore, they have been indicated to play a major role in the biogeochemical cycling of iron. In this study, we aimed to investigate the potential of viral lysis as a source of iron for marine heterotrophic bacteria. Viral lysates were derived from the marine heterotrophic bacterium, Vibrio natriegens PWH3a (A.K.A Vibrio alginolyticus). The bioavailability of Fe in the lysates was determined using a model heterotrophic bacterium, namely, Dokdonia sp. strain Dokd-P16, isolated from Fe-limited waters along Line P transect in the Northeastern Pacific Ocean. The bacteria were grown under Fe-deplete or Fe-replete conditions before being exposed to the viral lysate. Differential gene expression following exposure to the viral lysate was analyzed via RNA sequencing to identify differentially expressed genes under iron-replete and iron-deplete conditions. This study would provide novel insights into the role of viral lysis in heterotrophic bacteria in supplying bioavailable iron to other marine microorganisms under iron-limiting and non-limiting conditions. First, the marine heterotrophic bacterium genome, Dokdonia sp. strain Dokd-P16, was sequenced to provide a genomic context for the expression studies. Subsequently, the relative gene expression in Dokdonia sp. strain Dokd-P16 grown under Fe limiting and non-limiting conditions were analyzed. This transcriptomic approach would be utilized to elucidate genes regulated by Fe availability in Dokdonia sp. strain Dokd-P16, which indicate its Fe-related response viral lysate exposure. Taken together, in this study, the transcriptomic responses of Fe-limited and non-limited marine heterotrophic bacteria were analyzed, which provided novel insights into the biological availability of Fe from the viral lysates.
Project description:Vibrio vulnificus multiply rapidly in host tissues under iron overloaded conditions. To understand the effects of iron in the physiology of this pathogen we performed a genome-wide transcriptional analysis of this bacterium growing under three different iron concentrations. V.vulnificus CMCP6 cells were grown under three different iron concentrations (TSBS + EDDA 50uM, TSBS and TSBS + FAC 250 ug/ml) and samples taken at log phase. Keywords: Response to the iron concentration of the media Strains were grown to an OD600nm of 0.6 to 0.8 in TSBS, TSBS with the addition of 250 μg/ml FAC or TSBS with the addition of 50 μM EDDA. Three independent cultures of the V. vulnificus cells grown in each media, were combined and treated as a single sample for the RNA extraction to minimize culture variation. Two samples per condition were used for the microarray analysis. Cells were centrifuged and the pellets resuspended in RNAWiz reagent (Ambion®, Austin, TX). Total RNA was extracted from each strain according to the manufacturerâ??s instructions
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: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.