RNA Arbitrarily Primed PCR Survey of Genes Regulated by ToxR in the Deep-Sea Bacterium
            <i>Photobacterium profundum</i>
            Strain SS9

Bidle, Kelly A.; Bartlett, Douglas H.

doi:10.1128/jb.183.5.1688-1693.2001

Cited by 24 publications

(25 citation statements)

References 54 publications

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“…RNA arbitrarily primed PCR (RAP-PCR) was performed essentially as described previously (6) except that a mixture of 10-mer oligonucleotides with G:C contents of 50% were used as arbitrary primers (Genosys Biotechnologies, The Woodlands, Tex.). Following identification of putative regulated fragments, 32 P-labeled DNA bands of interest were excised from the dried gel by using a scalpel and placed into a microcentrifuge tube containing 50 l of Tris buffer (10 mM Tris-HCl, 1 mM EDTA; pH 8.0) for overnight elution at room temperature.…”

Section: Methodsmentioning

confidence: 99%

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

Millikan

Ruby

2003

J Bacteriol

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Flagellum-mediated motility of Vibrio fischeri is an essential factor in the bacterium's ability to colonize its host, the Hawaiian squid Euprymna scolopes. To begin characterizing the nature of the flagellar regulon, we have cloned a gene, designated flrA, from V. fischeri that encodes a putative 54 -dependent transcriptional activator. Genetic arrangement of the flrA locus in V. fischeri is similar to motility master-regulator operons of Vibrio cholerae and Vibrio parahaemolyticus. In addition, examination of regulatory regions of a number of flagellar operons in V. fischeri revealed apparent 54 recognition motifs, suggesting that the flagellar regulatory hierarchy is controlled by a similar mechanism to that described in V. cholerae. However, in contrast to its closest known relatives, flrA mutant strains of V. fischeri ES114 were completely abolished in swimming capability. Although flrA provided in trans restored motility to the flrA mutant, the complemented strain was unable to reach wild-type levels of symbiotic colonization in juvenile squid, suggesting a possible role for the proper expression of FlrA in regulating symbiotic colonization factors in addition to those required for motility. Comparative RNA arbitrarily primed PCR analysis of the flrA mutant and its wild-type parent revealed several differentially expressed transcripts. These results define a regulon that includes both flagellar structural genes and other genes apparently not involved in flagellum elaboration or function. Thus, the transcriptional activator FlrA plays an essential role in regulating motility, and apparently in modulating other symbiotic functions, in V. fischeri.

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Section: Methodsmentioning

confidence: 99%

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

Millikan

Ruby

2003

J Bacteriol

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“…In the toxR mutant, exopolysaccharide may be produced in larger amounts, which may either hinder motility and thus detachment of the bacteria or aid production of a thicker biofilm. Fourth, ToxR in P. profundum has been shown to regulate genes involved in the starvation response (4). Similar genes may be needed to signal the bacterium to detach from a biofilm on a surface and to find another nutrient source on which to form a biofilm.…”

Section: Vol 184 2002mentioning

confidence: 99%

A ToxR Homolog from Vibrio anguillarum Serotype O1 Regulates Its Own Production, Bile Resistance, and Biofilm Formation

et al. 2002

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ToxR, a transmembrane regulatory protein, has been shown to respond to environmental stimuli. To better understand how the aquatic bacterium Vibrio anguillarum, a fish pathogen, responds to environmental signals that may be necessary for survival in the aquatic and fish environment, toxR and toxS from V. anguillarum serotype O1 were cloned. The deduced protein sequences were 59 and 67% identical to the Vibrio cholerae ToxR and ToxS proteins, respectively. Deletion mutations were made in each gene and functional analyses were done. Virulence analyses using a rainbow trout model showed that only the toxR mutant was slightly decreased in virulence, indicating that ToxR is not a major regulator of virulence factors. The toxR mutant but not the toxS mutant was 20% less motile than the wild type. Like many regulatory proteins, ToxR was shown to negatively regulate its own expression. Outer membrane protein (OMP) preparations from both mutants indicated that ToxR and ToxS positively regulate a 38-kDa OMP. The 38-kDa OMP was shown to be a major OMP, which cross-reacted with an antiserum to OmpU, an outer membrane porin from V. cholerae, and which has an amino terminus 75% identical to that of OmpU. ToxR and to a lesser extent ToxS enhanced resistance to bile. Bile in the growth medium increased expression of the 38-kDa OMP but did not affect expression of ToxR. Interestingly, a toxR mutant forms a better biofilm on a glass surface than the wild type, suggesting a new role for ToxR in the response to environmental stimuli.Vibrio anguillarum is a highly pathogenic bacterium that causes terminal hemorrhagic septicemia in marine fish, resulting in great economic losses within aquaculture (1, 3). The disease vibriosis is associated with high rates of mortality and shares many features with invasive septicemic diseases in humans (1). The infection model of V. anguillarum in salmonid fish has been suggested to be a useful model for studying host-pathogen interactions.Although the exact mode of infection for V. anguillarum is still unclear, it most likely involves attachment to and colonization of host surfaces, followed by penetration of the tissues. Chemotactic motility has been suggested to aid the entry of V. anguillarum into the fish host (47). Furthermore, adhesion and invasion studies using a Chinook salmon embryo cell line and a set of isogenic motility mutants showed that invasion of but not adhesion to the cell line was significantly decreased in nonmotile or partially motile mutants (45). A smooth-swimming, chemotactic mutant, however, was hyperinvasive.V. anguillarum utilizes fish skin and intestinal mucus as chemoattractants (48). This mucus should induce smooth swimming, which may aid the entry of V. anguillarum into the fish through the mucus layers. These studies strongly suggest that active motility is required for invasion of the fish host. Once the bacterium has invaded the fish, motility is no longer needed for the progression of vibriosis (37,45,47).Several factors have been suggested to be important in the...

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“…Photobacterium profundum produces ToxR genes that mediate virulence expression (Bidle and Bartlett 2001;Ivanova et al 2004). Pseudoalteromonas tetraodonis (group #1) is known to produce tetrodotoxin (Do et al 1990;Ivanova et al 2001).…”

Section: Pathogenic Activities Of Bacterial Endobiontsmentioning

confidence: 99%

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

Schuett

Doepke

2009

Helgol Mar Res

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Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic ''terra incognita''. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including the production of cytotoxins, tetrodotoxin and R-toxin. Findings of haemolysis tests support the literature data. The potential producers are Endozoicimonas elysicola, Moritella viscosa, Photobacterium profundum, P. aliena, P. tetraodonis, Shewanella waksmanii, Vibrio splendidus, V. aestuarius, Arcobacter butzleri.

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RNA Arbitrarily Primed PCR Survey of Genes Regulated by ToxR in the Deep-Sea Bacterium Photobacterium profundum Strain SS9

Cited by 24 publications

References 54 publications

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

A ToxR Homolog from Vibrio anguillarum Serotype O1 Regulates Its Own Production, Bile Resistance, and Biofilm Formation

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

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RNA Arbitrarily Primed PCR Survey of Genes Regulated by ToxR in the Deep-Sea Bacterium Photobacterium profundum Strain SS9

Cited by 24 publications

References 54 publications

FlrA, a σ 54 -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

FlrA, a σ 54 -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

A ToxR Homolog from Vibrio anguillarum Serotype O1 Regulates Its Own Production, Bile Resistance, and Biofilm Formation

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

Contact Info

Product

Resources

About

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization

FlrA, a σ ⁵⁴ -Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization