Daniele Provenzano

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The transmembrane regulatory protein ToxR is required for expression of virulence factors in the human diarrheal pathogen Vibrio cholerae, including cholera toxin (CT) and the toxin coregulated pilus (TCP). ToxR is necessary for transcription of the gene encoding a second regulatory protein, ToxT, which is the direct transcriptional activator of CT and TCP(More)
Salmonella strains that lack or overproduce DNA adenine methylase (Dam) elicit a protective immune response to different Salmonella species. To generate vaccines against other bacterial pathogens, the dam genes of Yersinia pseudotuberculosis and Vibrio cholerae were disrupted but found to be essential for viability. Overproduction of Dam significantly(More)
The transmembrane transcriptional activators ToxR and TcpP modulate expression of Vibrio cholerae virulence factors by exerting control over toxT, which encodes the cytoplasmic transcriptional activator of the ctx, tcp, and acf virulence genes. However, ToxR, independently of TcpP and ToxT, activates and represses transcription of the genes encoding two(More)
Trichomonas vaginalis harbors a double-stranded (ds)-RNA virus, and the presence of virus is related to upregulated expression and phenotypic variation of a prominent immunogen (Khoshnan A, Alderete JF (1994) J Virol 68: 4 035–4 038). To further test the influence of virus on T. vaginalis, virus-infected (V+) isolates were compared to virus-free (V-),(More)
Trichomonas vaginalis, a sexually transmitted disease agent in humans, is readily lysed by activation of the alternative complement pathway. The parasite became resistant following growth in medium supplemented by iron compared to parasites grown in medium depleted of iron, which were readily killed by complement. The resistance to complement was dependent(More)
Vibrio cholerae is a gram-negative human intestinal pathogen that causes the diarrheal disease cholera. Humans acquire cholera by ingesting V. cholerae-contaminated food or water. Upon ingestion, V. cholerae encounters several barriers to colonization, including bile acid toxicity and antimicrobial products of the innate immune system. In many gram-negative(More)
BACKGROUND Trichomonas vaginalis, a worldwide distributed sexually transmitted protozoan, is remarkable for synthesis of numerous, distinct cysteine proteinases, the significance of which is evidenced by the presence in vivo of soluble proteinases in secretions and antiproteinase antibody in serum of patients with trichomonosis. These proteinases(More)
Trichomonas vaginalis is a protozoan parasite that causes a widely distributed sexually transmitted disease (STD). Since immunoglobulin G (IgG) antibodies to specific trichomonad immunogens are found in serum and vaginal washes (VWs) from patients with trichomoniasis, a potential mechanism of immune evasion by this parasite might be the ability of T.(More)
OmpT and OmpU are pore-forming proteins of the outer membrane of Vibrio cholerae, a pathogen that colonizes the intestine and produces cholera. Expression of the ompU and ompT genes is under the regulation of ToxR, a transmembrane transcriptional activator that also controls expression of virulence factors. It was recently shown that bile stimulates the(More)
Vibrio cholerae is a Gram-negative bacterial pathogen that consists of over 200 serogroups with differing pathogenic potential. Only strains that express the virulence factors cholera toxin (CT) and toxin-coregulated pilus (TCP) are capable of pandemic spread of cholera diarrhoea. Regardless, all V. cholerae strains sequenced to date harbour genes for the(More)