Integration Host Factor Positively Regulates Virulence Gene Expression in
            <i>Vibrio cholerae</i>

Stonehouse, Emily; Kovacikova, Gabriela; Taylor, Ronald K.; Skorupski, Karen

doi:10.1128/jb.00089-08

Cited by 71 publications

(74 citation statements)

References 71 publications

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“…It has also been shown that IHF activates Pe transcription indirectly via the alleviation of H-NS-mediated repression (van Ulsen et al, 1996). Recent reports further reinforce the role of IHF in alleviating H-NS silencing in Vibrio cholerae (Stonehouse et al, 2008) and in the csgD operon of E. coli (Ogasawara et al, 2010).…”

Section: Discussionmentioning

confidence: 75%

Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA

et al. 2011

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Coordination of the expression of Salmonella enterica invasion genes on Salmonella pathogenicity island 1 (SPI1) depends on a complex circuit involving several regulators that converge on expression of the hilA gene, which encodes a transcriptional activator (HilA) that modulates expression of the SPI1 virulence genes. Two of the global regulators that influence hilA expression are the nucleoid-associated proteins Hha and H-NS. They interact and form a complex that modulates gene expression. A chromosomal transcriptional fusion was constructed to assess the effects of these modulators on hilA transcription under several environmental conditions as well as at different stages of growth. The results obtained showed that these proteins play a role in silencing hilA expression at both low temperature and low osmolarity, irrespective of the growth phase. H-NS accounts for the main repressor activity. At high temperature and osmolarity, H-NS-mediated silencing completely ceases when cells enter the stationary phase, and hilA expression is induced. Mutants lacking IHF did not induce hilA in cells entering the stationary phase, and this lack of induction was dependent on the presence of H-NS. Band-shift assays and in vitro transcription data showed that for hilA induction under certain growth conditions, IHF is required to alleviate H-NS-mediated silencing.

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Section: Discussionmentioning

confidence: 75%

Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA

et al. 2011

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“…The existence of toxR gene is significant as a regulating agent for expression and function of several other genes, which are on turn responsible for the pathogenecity of V. cholerae (9,26,27). Furthermore, toxR gene does not horizontally get transferred from pathogenic strains to non-pathogenic ones (28); hence, it is specific to vibrionacea.…”

Section: Discussionmentioning

confidence: 99%

Facile and Rapid Detection of Vibrio cholerae by Multiplex PCR Based on ompU, ctxA, and toxR Genes

Alishahi

Fooladi

Mehrabadi

et al. 2013

Jundishapur J Microbiol

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Background: Several epidemic and endemic cases have been reported involving Vibrio cholerae (V. cholerae) as a causative organism in serious diarrheal diseases with high mortality. Hence, quick identification of this microorganism is critical for health care communities. Objectives: This investigation suggests an accurate, sensitive and rapid test to detect toxigenic and pathogenic species of V. cholerae simultaneously. Materials and methods:The standard bacteriological tests were utilized to isolate V. cholerae from the clinical samples. A multiplex PCR assay was carried out with three separate primers designed for ctxA, toxR and ompU genes, which play basic roles in toxigenicity and pathogenicity. To investigate the specificity of the designed primers, the amplification statuses of Salmonella typhi (S. typhi), Shigella dysenteriae (S. dysenteriae) and Escherichia coli O157:H7, as common intestinal pathogens, were evaluated. In addition, different concentrations of V. cholerae genome were used for determining the test sensitivity. Results: From the total of collected stool samples, 72 V. cholerae isolates were found and separated from the patients. All of them carried toxR and ompU genes, but ctxA gene was detected in only 61 isolates. The specificity and sensitivity of this test was 100%. Conclusions: Obtained data demonstrated that the designed assay is an accurate, easy, rapid, and cost-effective tool for detecting V. cholerae that can serve as an alternate to current bacteriological tests.

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“…Similar to IHF, H-NS also affects DNA architecture, and it is known to repress gene expression under conditions of low temperature or low osmolarity (189). While the conditions that control MvaT/MvaU activity are unknown, IHF antagonizes H-NS-dependent silencing of gene expression in bacterial pathogens, including E. coli, V. cholerae, and S. enterica (190)(191)(192). Further studies are needed to determine whether IHF antagonizes MvaT/MvaU-dependent repression of RsmZ.…”

Section: P Aeruginosamentioning

confidence: 99%

Regulation of Bacterial Virulence by Csr (Rsm) Systems

Vakulskas

Potts

Babitzke

et al. 2015

Microbiol Mol Biol Rev

299

400

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SUMMARY Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5′ untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens.

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Integration Host Factor Positively Regulates Virulence Gene Expression in Vibrio cholerae

Cited by 71 publications

References 71 publications

Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA

Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA

Facile and Rapid Detection of Vibrio cholerae by Multiplex PCR Based on ompU, ctxA, and toxR Genes

Regulation of Bacterial Virulence by Csr (Rsm) Systems

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