As the leading cause of hospital-acquired diarrhea, Clostridium difficile colonizes the large bowel of patients undergoing antibiotic therapy and produces two toxins, which cause notable disease pathologies. These two toxins, TcdA and TcdB, are encoded on a pathogenicity locus along with negative and positive regulators of their expression. Following expression and release from the bacterium, T...

Clostridium difficile is a major cause of antibiotic-associated colitis and is associated with significant morbidity and mortality. Glutamine (Gln) is a major fuel for the intestinal cell population. Alanyl-glutamine (Ala-Gln) is a dipeptide that is highly soluble and well tolerated. IEC-6 cells were used in the in vitro experiments. Cell morphology was evaluated by atomic force microscopy (AFM...

Toxin A (TcdA) and B (TcdB) from Clostridium difficile enter host cells by receptor-mediated endocytosis. A prerequisite for proper toxin action is the intracellular release of the glucosyltransferase domain by an inherent cysteine protease, which is allosterically activated by inositol hexaphosphate (IP6). We found that in in vitro assays, the C-terminally-truncated TcdA1-1065 was more efficie...

Virulent C. difficile toxins TcdA and TcdB invade host intestinal epithelia by endocytosis and use the acidic environment of intracellular vesicles for further processing and activation. We investigated the role of ClC-5, a chloride/proton exchanger expressed in the endosomes of gastrointestinal epithelial cells, in the activation and processing of C. difficile toxins. Enhanced intoxication by ...

Clostridium difficile is an emerging pathogen responsible for opportunistic infections in hospitals worldwide and is the main cause of antibiotic-associated pseudo-membranous colitis and diarrhea in humans. Clostridial toxins A and B (TcdA and TcdB) specifically bind to unknown glycoprotein(s) on the surface of epithelial cells in the host intestine, disrupting the intestinal barrier and ultima...

BACKGROUND Oral immunization with vaccines may be an effective strategy for prevention of Clostridium difficile infection (CDI). However, application of previously developed vaccines for preventing CDI has been limited due to various reasons. Here, we developed a recombinant Lactococcus lactis oral vaccine and evaluated its effect on a C. difficile-infected animal model established in golden ha...

Clostridium difficile infections can induce mild to severe diarrhoea and the often associated characteristic pseudomembranous colitis. Two protein toxins, the large glucosyltransferases TcdA and TcdB, are the main pathogenicity factors that can induce all clinical symptoms in animal models. The classical molecular mode of action of these homologous toxins is the inhibition of Rho GTPases by mon...

Certain amino acids, and cysteine in particular, promptly blocked toxin expression in Clostridium difficile strain VPI 10463 when added to late-exponential-phase peptone-yeast cultures, i.e. prior to normal induction of toxins A and B. Glucose reduced toxin yields by 80-fold, but only when supplemented at inoculation. Forty upregulated C. difficile proteins were identified during maximum toxin ...

In SaaS, since the service provider may be un-trusted, it is essential for tenants to enable query result correctness and completeness. However, existing data authentication methods can not fit well with the customized multi-tenants sharing storage mode. This paper put forward a multi-tenant data authentication model (TCDA). TCDA is a composite structure that constructs pivot authentication tre...

BACKGROUND Clostridium difficile-associated disease (CDAD) constitutes a great majority of hospital diarrhea cases in industrialized countries and is induced by two types of large toxin molecules: toxin A (TcdA) and toxin B (TcdB). Development of immunotherapeutic approaches, either active or passive, has seen a resurgence in recent years. Studies have described vaccine plasmids that express ei...