Anna D Tischler

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The newly recognized bacterial second messenger 3',5'-cyclic diguanylic acid (cyclic diguanylate (c-di-GMP)) has been shown to regulate a wide variety of bacterial behaviors and traits. Biosynthesis and degradation of c-di-GMP have been attributed to the GGDEF and EAL protein domains, respectively, based primarily on genetic evidence. Whereas the GGDEF(More)
While studying virulence gene regulation in Vibrio cholerae during infection of the host small intestine, we identified VieA as a two-component response regulator that contributes to activating expression of cholera toxin. Here we report that VieA represses transcription of Vibrio exopolysaccharide synthesis (vps) genes involved in biofilm formation by a(More)
Cyclic diguanylate (c-di-GMP) is an allosteric activator and second messenger implicated in the regulation of a variety of biological processes in diverse bacteria. In Vibrio cholerae, c-di-GMP has been shown to inversely regulate biofilm-specific and virulence gene expression, suggesting that c-di-GMP signaling is important for the transition of V.(More)
Vibrio cholerae, the causative agent of cholera, is a facultative human pathogen with intestinal and aquatic life cycles. The capacity of V. cholerae to recognize and respond to fluctuating parameters in its environment is critical to its survival. In many microorganisms, the second messenger, 3',5'-cyclic diguanylic acid (c-di-GMP), is believed to be(More)
The cyclic dinucleotide second messenger cyclic diguanylate (c-diGMP) has been implicated in regulation of cell surface properties in several bacterial species, including Vibrio cholerae. Expression of genes required for V. cholerae biofilm formation is activated by an increased intracellular c-diGMP concentration. The response regulator VieA, which(More)
The genes encoding cholera toxin (CT), ctxAB, are coregulated with those for other Vibrio cholerae virulence factors by a cascade of transcriptional activators, including ToxR, TcpP, and ToxT. Additional regulators that modulate expression of ctxAB during infection were recently identified in a genetic selection. A transposon insertion in vieS, the sensor(More)
Vibrio cholerae is a facultative intestinal pathogen that lives in aquatic environments, often in association with planktonic species. In the suckling mouse, oral inoculation with V. cholerae leads to intestinal colonization and symptoms of diarrheal disease. Results reported here indicate a role for the alternative sigma factor, RpoS, in intestinal(More)
Differences in whole-genome expression patterns between the classical and El Tor biotypes of Vibrio cholerae O1 were determined under conditions that induce virulence gene expression in the classical biotype. A total of 524 genes (13.5% of the genome) were found to be differentially expressed in the two biotypes. The expression of genes encoding proteins(More)
Mycobacterium tuberculosis persists in the tissues of mammalian hosts despite inducing a robust immune response dominated by the macrophage-activating cytokine gamma interferon (IFN-γ). We identified the M. tuberculosis phosphate-specific transport (Pst) system component PstA1 as a factor required to resist IFN-γ-dependent immunity. A ΔpstA1 mutant was(More)
Phosphorelay systems are important mediators of signal transduction during bacterial adaptation to new environments. Previously we described the vieSAB operon, encoding a putative three-protein component phosphorelay involved in regulating Vibrio cholerae virulence gene expression. At least part of the regulatory activity of VieSAB is exerted through the(More)