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Sample records for difficile toxin cdt

  1. Clostridium difficile toxin CDT induces formation of microtubule-based protrusions and increases adherence of bacteria.

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    Carsten Schwan

    2009-10-01

    Full Text Available Clostridium difficile causes antibiotic-associated diarrhea and pseudomembranous colitis by production of the Rho GTPase-glucosylating toxins A and B. Recently emerging hypervirulent Clostridium difficile strains additionally produce the binary ADP-ribosyltransferase toxin CDT (Clostridium difficile transferase, which ADP-ribosylates actin and inhibits actin polymerization. Thus far, the role of CDT as a virulence factor is not understood. Here we report by using time-lapse- and immunofluorescence microscopy that CDT and other binary actin-ADP-ribosylating toxins, including Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin, induce redistribution of microtubules and formation of long (up to >150 microm microtubule-based protrusions at the surface of intestinal epithelial cells. The toxins increase the length of decoration of microtubule plus-ends by EB1/3, CLIP-170 and CLIP-115 proteins and cause redistribution of the capture proteins CLASP2 and ACF7 from microtubules at the cell cortex into the cell interior. The CDT-induced microtubule protrusions form a dense meshwork at the cell surface, which wrap and embed bacterial cells, thereby largely increasing the adherence of Clostridia. The study describes a novel type of microtubule structure caused by less efficient microtubule capture and offers a new perspective for the pathogenetic role of CDT and other binary actin-ADP-ribosylating toxins in host-pathogen interactions.

  2. EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin.

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    Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Azarnia Tehran, Domenico; Montecucco, Cesare; Barth, Holger

    2016-04-01

    The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins.

  3. EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin

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    Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R.; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-01-01

    The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins. PMID:27043629

  4. The Binary Toxin CDT of Clostridium difficile as a Tool for Intracellular Delivery of Bacterial Glucosyltransferase Domains

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    Lara-Antonia Beer

    2018-06-01

    Full Text Available Binary toxins are produced by several pathogenic bacteria. Examples are the C2 toxin from Clostridium botulinum, the iota toxin from Clostridium perfringens, and the CDT from Clostridium difficile. All these binary toxins have ADP-ribosyltransferases (ADPRT as their enzymatically active component that modify monomeric actin in their target cells. The binary C2 toxin was intensively described as a tool for intracellular delivery of allogenic ADPRTs. Here, we firstly describe the binary toxin CDT from C. difficile as an effective tool for heterologous intracellular delivery. Even 60 kDa glucosyltransferase domains of large clostridial glucosyltransferases can be delivered into cells. The glucosyltransferase domains of five tested large clostridial glucosyltransferases were successfully introduced into cells as chimeric fusions to the CDTa adapter domain (CDTaN. Cell uptake was demonstrated by the analysis of cell morphology, cytoskeleton staining, and intracellular substrate glucosylation. The fusion toxins were functional only when the adapter domain of CDTa was N-terminally located, according to its native orientation. Thus, like other binary toxins, the CDTaN/b system can be used for standardized delivery systems not only for bacterial ADPRTs but also for a variety of bacterial glucosyltransferase domains.

  5. Stool C difficile toxin

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    ... toxin; Colitis - toxin; Pseudomembranous - toxin; Necrotizing colitis - toxin; C difficile - toxin ... be analyzed. There are several ways to detect C difficile toxin in the stool sample. Enzyme immunoassay ( ...

  6. CdtR Regulates TcdA and TcdB Production in Clostridium difficile.

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    Shelley A Lyon

    2016-07-01

    Full Text Available Clostridium difficile is a global health burden and the leading cause of antibiotic-associated diarrhoea worldwide, causing severe gastrointestinal disease and death. Three well characterised toxins are encoded by this bacterium in two genetic loci, specifically, TcdB (toxin B and TcdA (toxin A in the Pathogenicity Locus (PaLoc and binary toxin (CDT in the genomically distinct CDT locus (CdtLoc. Toxin production is controlled by regulators specific to each locus. The orphan response regulator, CdtR, encoded within the CdtLoc, up-regulates CDT production. Until now there has been no suggestion that CdtR influences TcdA and TcdB production since it is not carried by all PaLoc-containing strains and CdtLoc is not linked genetically to PaLoc. Here we show that, in addition to CDT, CdtR regulates TcdA and TcdB production but that this effect is strain dependent. Of clinical relevance, CdtR increased the production of TcdA, TcdB and CDT in two epidemic ribotype 027 human strains, modulating their virulence in a mouse infection model. Strains traditionally from animal lineages, notably ribotype 078 strains, are increasingly being isolated from humans and their genetic and phenotypic analysis is critical for future studies on this important pathogen. Here we show that CdtR-mediated toxin regulation did not occur in other strain backgrounds, including a ribotype 078 animal strain. The finding that toxin gene regulation is strain dependent highlights the regulatory diversity between C. difficile isolates and the importance of studying virulence regulation in diverse lineages and clinically relevant strains. Our work provides the first evidence that TcdA, TcdB and CDT production is linked by a common regulatory mechanism and that CdtR may act as a global regulator of virulence in epidemic 027 strains.

  7. Distinct Roles for CdtA and CdtC during Intoxication by Cytolethal Distending Toxins.

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    Shandee D Dixon

    Full Text Available Cytolethal distending toxins (CDTs are heterotrimeric protein exotoxins produced by a diverse array of Gram-negative pathogens. The enzymatic subunit, CdtB, possesses DNase and phosphatidylinositol 3-4-5 trisphosphate phosphatase activities that induce host cell cycle arrest, cellular distension and apoptosis. To exert cyclomodulatory and cytotoxic effects CDTs must be taken up from the host cell surface and transported intracellularly in a manner that ultimately results in localization of CdtB to the nucleus. However, the molecular details and mechanism by which CDTs bind to host cells and exploit existing uptake and transport pathways to gain access to the nucleus are poorly understood. Here, we report that CdtA and CdtC subunits of CDTs derived from Haemophilus ducreyi (Hd-CDT and enteropathogenic E. coli (Ec-CDT are independently sufficient to support intoxication by their respective CdtB subunits. CdtA supported CdtB-mediated killing of T-cells and epithelial cells that was nearly as efficient as that observed with holotoxin. In contrast, the efficiency by which CdtC supported intoxication was dependent on the source of the toxin as well as the target cell type. Further, CdtC was found to alter the subcellular trafficking of Ec-CDT as determined by sensitivity to EGA, an inhibitor of endosomal trafficking, colocalization with markers of early and late endosomes, and the kinetics of DNA damage response. Finally, host cellular cholesterol was found to influence sensitivity to intoxication mediated by Ec-CdtA, revealing a role for cholesterol or cholesterol-rich membrane domains in intoxication mediated by this subunit. In summary, data presented here support a model in which CdtA and CdtC each bind distinct receptors on host cell surfaces that direct alternate intracellular uptake and/or trafficking pathways.

  8. A new functional site W115 in CdtA is critical for Aggregatibacter actinomycetemcomitans cytolethal distending toxin.

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    Lu Li

    Full Text Available Aggregatibacter actinomycetemcomitans, a specific pathogen of localized aggressive periodontitis, produces a cytolethal distending toxin (CDT that arrests eukaryotic cells irreversibly in G0/G1 or G2/M phase of the cell cycle. Although structural studies show that the aromatic patch region of CdtA plays an important role in its biological activity, the functional sites of CdtA have not been firmly established. In this study, site-specific mutagenesis strategy was employed for cdtA point mutations construction so as to examine the contributions of individual amino acids to receptor binding and the biological activity of holotoxin. The binding ability was reduced in CdtA(Y181ABC holotoxin and the biological function of CDT was not weaken in CdtA(Y105ABC, CdtA(Y125ABC, CdtA(F109ABC and CdtA(S106NBC holotoxin suggesting that these sites were not critical to CDT. But the binding activity and cell cycle arrest ability of holotoxin complexes were inhibited in CdtA(W115GBC. And this site did not affect the holotoxin assembly by size exclusion chromatography. Therefore, W115 might be a critical site of CdtA binding ability. These findings suggest that the functional sites of CdtA are not only in the aromatic patch region. W115, the new functional site is critical for receptor binding and cell cycle arrest, which provides potential targets for pharmacological disruption of CDT activity.

  9. Clostridium difficile chimeric toxin receptor binding domain vaccine induced protection against different strains in active and passive challenge models.

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    Tian, Jing-Hui; Glenn, Gregory; Flyer, David; Zhou, Bin; Liu, Ye; Sullivan, Eddie; Wu, Hua; Cummings, James F; Elllingsworth, Larry; Smith, Gale

    2017-07-24

    Clostridium difficile is the number one cause of nosocomial antibiotic-associated diarrhea in developed countries. Historically, pathogenesis was attributed two homologous glucosylating toxins, toxin-A (TcdA) and toxin-B (TcdB). Over the past decade, however, highly virulent epidemic strains of C. difficile (B1/NAP1/027) have emerged and are linked to an increase in morbidity and mortality. Increased virulence is attributed to multiple factors including: increased production of A- and B-toxins; production of binary toxin (CDT); and the emergence of more toxic TcdB variants (TcdB (027) ). TcdB (027) is more cytotoxicity to cells; causes greater tissue damage and toxicity in animals; and is antigenically distinct from historical TcdB (TcdB (003) ). Broadly protective vaccines and therapeutic antibody strategies, therefore, may target TcdA, TcdB variants and CDT. To facilitate the generation of multivalent toxin-based C. difficile vaccines and therapeutic antibodies, we have generated fusion proteins constructed from the receptor binding domains (RBD) of TcdA, TcdB (003) , TcdB (027) and CDT. Herein, we describe the development of a trivalent toxin (T-toxin) vaccine (CDTb/TcdB (003) /TcdA) and quadravalent toxin (Q-toxin) vaccine (CDTb/TcB (003) /TcdA/TcdB (027) ) fusion proteins that retain the protective toxin neutralizing epitopes. Active immunization of mice or hamsters with T-toxin or Q-toxin fusion protein vaccines elicited the generation of toxin neutralizing antibodies to each of the toxins. Hamsters immunized with the Q-toxin vaccine were broadly protected against spore challenge with historical C. difficile 630 (toxinotype 0/ribotype 003) and epidemic NAP1 (toxinotype III/ribotype 027) strains. Fully human polyclonal antitoxin IgG was produced by immunization of transgenic bovine with these fusion proteins. In passive transfer studies, mice were protected against lethal toxin challenge. Hamsters treated with human antitoxin IgG were completely protected when

  10. Prevalence and pathogenicity of binary toxin–positive Clostridium difficile strains that do not produce toxins A and B

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    C. Eckert

    2015-01-01

    Full Text Available Clostridium difficile causes antibiotic-associated diarrhoea and pseudomembranous colitis. The main virulence factors of C. difficile are the toxins A (TcdA and B (TcdB. A third toxin, called binary toxin (CDT, can be detected in 17% to 23% of strains, but its role in human disease has not been clearly defined. We report six independent cases of patients with diarrhoea suspected of having C. difficile infection due to strains from toxinotype XI/PCR ribotype 033 or 033-like, an unusual toxinotype/PCR ribotype positive for CDT but negative for TcdA and TcdB. Four patients were considered truly infected by clinicians and were specifically treated with oral metronidazole. One of the cases was identified during a prevalence study of A−B−CDT+ strains. In this study, we screened a French collection of 220 nontoxigenic strains and found only one (0.5% toxinotype XI/PCR ribotype 033 or 033-like strain. The description of such strains raises the question of the role of binary toxin as a virulence factor and could have implications for laboratory diagnostics that currently rarely include testing for binary toxin.

  11. Prevalence and Characterization of a Binary Toxin (Actin-Specific ADP-Ribosyltransferase) from Clostridium difficile

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    Gonçalves, Carina; Decré, Dominique; Barbut, Frédéric; Burghoffer, Béatrice; Petit, Jean-Claude

    2004-01-01

    In addition to the two large clostridial cytotoxins (TcdA and TcdB), some strains of Clostridium difficile also produce an actin-specific ADP-ribosyltransferase, called binary toxin CDT. We used a PCR method and Southern blotting for the detection of genes encoding the enzymatic (CDTa) and binding (CDTb) components of the binary toxin in 369 strains isolated from patients with suspected C. difficile-associated diarrhea or colitis. Twenty-two strains (a prevalence of 6%) harbored both genes. When binary toxin production was assessed by Western blotting, 19 of the 22 strains reacted with antisera against the iota toxin of C. perfringens (anti-Ia and anti-Ib). Additionally, binary toxin activity, detected by the ADP-ribosyltransferase assay, was present in only 17 of the 22 strains. Subsequently, all 22 binary toxin-positive strains were tested for the production of toxins TcdA and TcdB, toxinotyped, and characterized by serogrouping, PCR ribotyping, arbitrarily primed PCR, and pulsed-field gel electrophoresis. All binary toxin-positive strains also produced TcdB and/or TcdA. However, they had significant changes in the tcdA and tcdB genes and belonged to variant toxinotypes III, IV, V, VII, IX, and XIII. We could differentiate 16 profiles by using typing methods, indicating that most of the binary toxin-positive strains were unrelated. PMID:15131151

  12. Crystal structure of Clostridium difficile toxin A

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    Chumbler, Nicole M.; Rutherford, Stacey A.; Zhang, Zhifen; Farrow, Melissa A.; Lisher, John P.; Farquhar, Erik; Giedroc, David P.; Spiller, Benjamin W.; Melnyk, Roman A.; Lacy, D. Borden

    2016-01-11

    Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host. The multidomain toxins enter cells by receptor-mediated endocytosis and, upon exposure to the low pH of the endosome, insert into and deliver two enzymatic domains across the membrane. Eukaryotic inositol-hexakisphosphate (InsP6) binds an autoprocessing domain to activate a proteolysis event that releases the N-terminal glucosyltransferase domain into the cytosol. Here, we report the crystal structure of a 1,832-amino-acid fragment of TcdA (TcdA1832), which reveals a requirement for zinc in the mechanism of toxin autoprocessing and an extended delivery domain that serves as a scaffold for the hydrophobic α-helices involved in pH-dependent pore formation. A surface loop of the delivery domain whose sequence is strictly conserved among all large clostridial toxins is shown to be functionally important, and is highlighted for future efforts in the development of vaccines and novel therapeutics.

  13. The role of toxins in Clostridium difficile infection.

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    Chandrasekaran, Ramyavardhanee; Lacy, D Borden

    2017-11-01

    Clostridium difficile is a bacterial pathogen that is the leading cause of nosocomial antibiotic-associated diarrhea and pseudomembranous colitis worldwide. The incidence, severity, mortality and healthcare costs associated with C. difficile infection (CDI) are rising, making C. difficile a major threat to public health. Traditional treatments for CDI involve use of antibiotics such as metronidazole and vancomycin, but disease recurrence occurs in about 30% of patients, highlighting the need for new therapies. The pathogenesis of C. difficile is primarily mediated by the actions of two large clostridial glucosylating toxins, toxin A (TcdA) and toxin B (TcdB). Some strains produce a third toxin, the binary toxin C. difficile transferase, which can also contribute to C. difficile virulence and disease. These toxins act on the colonic epithelium and immune cells and induce a complex cascade of cellular events that result in fluid secretion, inflammation and tissue damage, which are the hallmark features of the disease. In this review, we summarize our current understanding of the structure and mechanism of action of the C. difficile toxins and their role in disease. Published by Oxford University Press on behalf of FEMS 2017.

  14. The Regulatory Networks That Control Clostridium difficile Toxin Synthesis

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    Martin-Verstraete, Isabelle; Peltier, Johann; Dupuy, Bruno

    2016-01-01

    The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota caused by antibiotic treatment. The symptoms of C. difficile infection are essentially caused by the production of two exotoxins: TcdA and TcdB. Moreover, for severe forms of disease, the spectrum of diseases caused by C. difficile has also been correlated to the levels of toxins that are produced during host infection. This observation strengthened the idea that the regulation of toxin synthesis is an important part of C. difficile pathogenesis. This review summarizes our current knowledge about the regulators and sigma factors that have been reported to control toxin gene expression in response to several environmental signals and stresses, including the availability of certain carbon sources and amino acids, or to signaling molecules, such as the autoinducing peptides of quorum sensing systems. The overlapping regulation of key metabolic pathways and toxin synthesis strongly suggests that toxin production is a complex response that is triggered by bacteria in response to particular states of nutrient availability during infection. PMID:27187475

  15. Comparison of five assays for detection of Clostridium difficile toxin.

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    Chapin, Kimberle C; Dickenson, Roberta A; Wu, Fongman; Andrea, Sarah B

    2011-07-01

    Performance characteristics of five assays for detection of Clostridium difficile toxin were compared using fresh stool samples from patients with C. difficile infection (CDI). Assays were performed simultaneously and according to the manufacturers' instructions. Patients were included in the study if they exhibited clinical symptoms consistent with CDI. Nonmolecular assays included glutamate dehydrogenase antigen tests, with positive findings followed by the Premier Toxin A and B Enzyme Immunoassay (GDH/EIA), and the C. Diff Quik Chek Complete test. Molecular assays (PCR) included the BD GeneOhm Cdiff Assay, the Xpert C. difficile test, and the ProGastro Cd assay. Specimens were considered true positive if results were positive in two or more assays. For each method, the Youden index was calculated and cost-effectiveness was analyzed. Of 81 patients evaluated, 26 (32.1%) were positive for CDI. Sensitivity of the BD GeneOhm Cdiff assay, the Xpert C. difficile test, the ProGastro Cd assay, C. Diff Quik Chek Complete test, and two-step GDH/EIA was 96.2%, 96.2%, 88.5%, 61.5%, and 42.3%, respectively. Specificity of the Xpert C. difficile test was 96.4%, and for the other four assays was 100%. Compared with nonmolecular methods, molecular methods detected 34.7% more positive specimens. Assessment of performance characteristics and cost-effectiveness demonstrated that the BD GeneOhm Cdiff assay yielded the best results. While costly, the Xpert C. difficile test required limited processing and yielded rapid results. Because of discordant results, specimen processing, and extraction equipment requirements, the ProGastro Cd assay was the least favored molecular assay. The GDH/EIA method lacked sufficient sensitivity to be recommended. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  16. Comparison of Five Assays for Detection of Clostridium difficile Toxin

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    Chapin, Kimberle C.; Dickenson, Roberta A.; Wu, Fongman; Andrea, Sarah B.

    2011-01-01

    Performance characteristics of five assays for detection of Clostridium difficile toxin were compared using fresh stool samples from patients with C. difficile infection (CDI). Assays were performed simultaneously and according to the manufacturers' instructions. Patients were included in the study if they exhibited clinical symptoms consistent with CDI. Nonmolecular assays included glutamate dehydrogenase antigen tests, with positive findings followed by the Premier Toxin A and B Enzyme Immunoassay (GDH/EIA), and the C. Diff Quik Chek Complete test. Molecular assays (PCR) included the BD GeneOhm Cdiff Assay, the Xpert C. difficile test, and the ProGastro Cd assay. Specimens were considered true positive if results were positive in two or more assays. For each method, the Youden index was calculated and cost-effectiveness was analyzed. Of 81 patients evaluated, 26 (32.1%) were positive for CDI. Sensitivity of the BD GeneOhm Cdiff assay, the Xpert C. difficile test, the ProGastro Cd assay, C. Diff Quik Chek Complete test, and two-step GDH/EIA was 96.2%, 96.2%, 88.5%, 61.5%, and 42.3%, respectively. Specificity of the Xpert C. difficile test was 96.4%, and for the other four assays was 100%. Compared with nonmolecular methods, molecular methods detected 34.7% more positive specimens. Assessment of performance characteristics and cost-effectiveness demonstrated that the BD GeneOhm Cdiff assay yielded the best results. While costly, the Xpert C. difficile test required limited processing and yielded rapid results. Because of discordant results, specimen processing, and extraction equipment requirements, the ProGastro Cd assay was the least favored molecular assay. The GDH/EIA method lacked sufficient sensitivity to be recommended. PMID:21704273

  17. Faecal excretion of brush border membrane enzymes in patients with clostridium difficile diarrhoea

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    Katyal R

    2002-01-01

    Full Text Available PURPOSE: To look for the presence of intestinal brush border membrane (BBM enzymes in the faecal samples of patients with Clostridium difficile association. METHODS: One hundred faecal samples were investigated for C.difficile toxin (CDT. Simultaneous assays for faecal excretion of intestinal BBM enzymes viz., disaccharidases, alkaline phosphatase (AP and leucine aminopeptidase (LAP were also done. RESULTS: C.difficile toxin was detected in 25 (25% of the samples with a titre ranging from 10 to 160. No significant difference (p>0.05 was seen between the CDT positive and negative groups with any of the disaccharidases studied. However, significant increase (pC.difficile diarrhoea.

  18. Diagnosis of Clostridium difficile

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    Jensen, M B F; Olsen, K E P; Nielsen, X C

    2015-01-01

    The diagnosis of Clostridium difficile infection (CDI) requires the detection of toxigenic C. difficile or its toxins and a clinical assessment. We evaluated the performance of four nucleic acid amplification tests (NAATs) detecting toxigenic C. difficile directly from faeces compared to routine...... ribotyping and toxinotyping (TT) were performed on culture-positive samples. In parallel, the samples were analysed by four NAATs; two targeting tcdA or tcdB (illumigene® C. difficile and PCRFast® C. difficile A/B) and two multi-target real-time (RT) PCR assays also targeting cdt and tcdC alleles...... characteristic of epidemic and potentially more virulent PCR ribotypes 027, 066 and 078 (GeneXpert® C. difficile/Epi and an 'in-house RT PCR' two-step algorithm). The multi-target assays were significantly more sensitive compared to routine toxigenic culture (p 

  19. The Cytolethal Distending Toxin Subunit CdtB of Helicobacter hepaticus Promotes Senescence and Endoreplication in Xenograft Mouse Models of Hepatic and Intestinal Cell Lines

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    Christelle Péré-Védrenne

    2017-06-01

    Full Text Available Cytolethal distending toxins (CDTs are common among pathogenic bacteria of the human and animal microbiota. CDTs exert cytopathic effets, via their active CdtB subunit. No clear description of those cytopathic effects has been reported at the cellular level in the target organs in vivo. In the present study, xenograft mouse models of colon and liver cell lines were set up to study the effects of the CdtB subunit of Helicobacter hepaticus. Conditional transgenic cell lines were established, validated in vitro and then engrafted into immunodeficient mice. After successful engraftment, mice were treated with doxycyclin to induce the expression of transgenes (red fluorescent protein, CdtB, and mutated CdtB. For both engrafted cell lines, results revealed a delayed tumor growth and a reduced tumor weight in CdtB-expressing tumors compared to controls. CdtB-derived tumors showed γ-H2AX foci formation, an increase in apoptosis, senescence, p21 and Ki-67 nuclear antigen expression. No difference in proliferating cells undergoing mitosis (phospho-histone H3 was observed. CdtB intoxication was also associated with an overexpression of cytokeratins in cells at the invasive front of the tumor as well as an increase in ploidy. All these features are hallmarks of endoreplication, as well as aggressiveness in cancer. These effects were dependent on the histidine residue at position 265 of the CdtB, underlying the importance of this residue in CdtB catalytic activity. Taken together, these data indicate that the CdtB triggers senescence and cell endoreplication leading to giant polyploid cells in these xenograft mouse models.

  20. Fidaxomicin Inhibits Clostridium difficile Toxin A-Mediated Enteritis in the Mouse Ileum

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    Koon, Hon Wai; Ho, Samantha; Hing, Tressia C.; Cheng, Michelle; Chen, Xinhua; Ichikawa, Yoshi; Kelly, Ciarán P.

    2014-01-01

    Clostridium difficile infection (CDI) is a common, debilitating infection with high morbidity and mortality. C. difficile causes diarrhea and intestinal inflammation by releasing two toxins, toxin A and toxin B. The macrolide antibiotic fidaxomicin was recently shown to be effective in treating CDI, and its beneficial effect was associated with fewer recurrent infections in CDI patients. Since other macrolides possess anti-inflammatory properties, we examined the possibility that fidaxomicin alters C. difficile toxin A-induced ileal inflammation in mice. The ileal loops of anesthetized mice were injected with fidaxomicin (5, 10, or 20 μM), and after 30 min, the loops were injected with purified C. difficile toxin A or phosphate-buffered saline alone. Four hours after toxin A administration, ileal tissues were processed for histological evaluation (epithelial cell damage, neutrophil infiltration, congestion, and edema) and cytokine measurements. C. difficile toxin A caused histologic damage, evidenced by increased mean histologic score and ileal interleukin-1β (IL-1β) protein and mRNA expression. Treatment with fidaxomicin (20 μM) or its primary metabolite, OP-1118 (120 μM), significantly inhibited toxin A-mediated histologic damage and reduced the mean histology score and ileal IL-1β protein and mRNA expression. Both fidaxomicin and OP-1118 reduced toxin A-induced cell rounding in human colonic CCD-18Co fibroblasts. Treatment of ileal loops with vancomycin (20 μM) and metronidazole (20 μM) did not alter toxin A-induced histologic damage and IL-1β protein expression. In addition to its well known antibacterial effects against C. difficile, fidaxomicin may possess anti-inflammatory activity directed against the intestinal effects of C. difficile toxins. PMID:24890583

  1. TcdC does not significantly repress toxin expression in Clostridium difficile 630ΔErm.

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    Dennis Bakker

    Full Text Available In the past decade, Clostridium difficile has emerged as an important gut pathogen. Symptoms of C. difficile infection range from mild diarrhea to pseudomembranous colitis, sometimes resulting in colectomy or death. The main virulence factors of C. difficile are toxin A and toxin B. Besides the genes encoding these toxins (tcdA and tcdB, the pathogenicity locus (PaLoc also contains genes encoding a sigma factor (tcdR and a putative anti-sigma factor (tcdC. The important role of TcdR as a sigma factor for toxin expression is undisputed, whereas the role of TcdC as an anti-sigma factor, inhibiting toxin expression, is currently the subject of debate. To clarify the role of TcdC in toxin expression, we generated an isogenic ClosTron-based mutant of tcdC in Clostridium difficile strain 630Δ Erm (CT::tcdC and determined the transcription levels of the PaLoc genes and the expression levels of the toxins in the wild type strain and the tcdC mutant strain. We found only minor differences in transcription levels of the PaLoc genes between the wild type and CT::tcdC strains and total toxin levels did not significantly differ either. These results suggest that in C. difficile 630Δerm TcdC is not a major regulator of toxin expression under the conditions tested.

  2. Characterization of a Toxin A-Negative, Toxin B-Positive Strain of Clostridium difficile Responsible for a Nosocomial Outbreak of Clostridium difficile-Associated Diarrhea

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    Alfa, Michelle J.; Kabani, Amin; Lyerly, David; Moncrief, Scott; Neville, Laurie M.; Al-Barrak, Ali; Harding, Godfrey K. H.; Dyck, Brenda; Olekson, Karen; Embil, John M.

    2000-01-01

    Clostridium difficile-associated diarrhea (CAD) is a very common nosocomial infection that contributes significantly to patient morbidity and mortality as well as to the cost of hospitalization. Previously, strains of toxin A-negative, toxin B-positive C. difficile were not thought to be associated with clinically significant disease. This study reports the characterization of a toxin A-negative, toxin B-positive strain of C. difficile that was responsible for a recently described nosocomial outbreak of CAD. Analysis of the seven patient isolates from the outbreak by pulsed-field gel electrophoresis indicated that this outbreak was due to transmission of a single strain of C. difficile. Our characterization of this strain (HSC98) has demonstrated that the toxin A gene lacks 1.8 kb from the carboxy repetitive oligopeptide (CROP) region but apparently has no other major deletions from other regions of the toxin A or toxin B gene. The remaining 1.3-kb fragment of the toxin A CROP region from strain HSC98 showed 98% sequence homology with strain 1470, previously reported by M. Weidmann in 1997 (GenBank accession number Y12616), suggesting that HSC98 is toxinotype VIII. The HSC98 strain infecting patients involved in this outbreak produced the full spectrum of clinical illness usually associated with C. difficile-associated disease. This pathogenic spectrum was manifest despite the inability of this strain to alter tight junctions as determined by using in vitro tissue culture testing, which suggested that no functional toxin A was produced by this strain. PMID:10878068

  3. Sensitive assays enable detection of serum IgG antibodies against Clostridium difficile toxin A and toxin B in healthy subjects and patients with Clostridium difficile infection.

    Science.gov (United States)

    Zhao, Xuemei; Bender, Florent; Shukla, Rajiv; Kang, John J; Caro-Aguilar, Ivette; Laterza, Omar F

    2016-04-01

    Pathogenic Clostridium difficile produces two proinflammatory exotoxins, toxin A and toxin B. Low level of serum antitoxin IgG antibodies is a risk factor for the development of primary and recurrent C. difficile infection (CDI). We developed and validated two sensitive, titer-based electrochemiluminescence assays for the detection of serum antibody levels against C. difficile toxins A and B. These assays demonstrated excellent precision. The sensitivity of the assays allowed the detection of antitoxin A and antitoxin B IgG antibodies in all tested serum samples during assay validation. The validated titer-based assays enable assessment of antitoxin A and antitoxin B IgG antibodies as potential biomarkers to identify patients with CDI at increased risk for CDI recurrence.

  4. Spore formation and toxin production in Clostridium difficile biofilms.

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    Ekaterina G Semenyuk

    Full Text Available The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA, polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

  5. Spore formation and toxin production in Clostridium difficile biofilms.

    Science.gov (United States)

    Semenyuk, Ekaterina G; Laning, Michelle L; Foley, Jennifer; Johnston, Pehga F; Knight, Katherine L; Gerding, Dale N; Driks, Adam

    2014-01-01

    The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA), polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

  6. A 3D intestinal tissue model supports Clostridioides difficile germination, colonization, toxin production and epithelial damage.

    Science.gov (United States)

    Shaban, Lamyaa; Chen, Ying; Fasciano, Alyssa C; Lin, Yinan; Kaplan, David L; Kumamoto, Carol A; Mecsas, Joan

    2018-04-01

    Endospore-forming Clostridioides difficile is a causative agent of antibiotic-induced diarrhea, a major nosocomial infection. Studies of its interactions with mammalian tissues have been hampered by the fact that C. difficile requires anaerobic conditions to survive after spore germination. We recently developed a bioengineered 3D human intestinal tissue model and found that low O 2 conditions are produced in the lumen of these tissues. Here, we compared the ability of C. difficile spores to germinate, produce toxin and cause tissue damage in our bioengineered 3D tissue model versus in a 2D transwell model in which human cells form a polarized monolayer. 3D tissue models or 2D polarized monolayers on transwell filters were challenged with the non-toxin producing C. difficile CCUG 37787 serotype X (ATCC 43603) and the toxin producing UK1 C. difficile spores in the presence of the germinant, taurocholate. Spores germinated in both the 3D tissue model as well as the 2D transwell system, however toxin activity was significantly higher in the 3D tissue models compared to the 2D transwells. Moreover, the epithelium damage in the 3D tissue model was significantly more severe than in 2D transwells and damage correlated significantly with the level of toxin activity detected but not with the amount of germinated spores. Combined, these results show that the bioengineered 3D tissue model provides a powerful system with which to study early events leading to toxin production and tissue damage of C. difficile with mammalian cells under anaerobic conditions. Furthermore, these systems may be useful for examining the effects of microbiota, novel drugs and other potential therapeutics directed towards C. difficile infections. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Comparing ImmunoCard with two EIA assays for Clostridium difficile toxins.

    Science.gov (United States)

    Chan, Edward L; Seales, Diane; Drum, Hong

    2009-01-01

    To compare three Clostridium difficile EIA kits for the detection of C. difficile toxins from clinical specimens. A total of 287 fresh and stored stool specimens were tested using all three assays. Stools with discrepant results were sent to a reference laboratory for tissue cytotoxin assay. Trinity Medical Center, a community hospital with network hospitals. Patients with diarrhea submitted stools for detection of C. difficile toxins. Of the 287 stool specimens, 116 were positive and 171 negative for C. difficile toxins. The sensitivity, specificity, and positive and negative predictive values of Meridian EIA assay were 99.1, 97.7, 96.6, and 99.4%; ImmunoCard were 100, 98.2, 97.5, and 100%; BioStar OIA assay were 94, 98.8, 98.2, and 96% respectively. ImmunoCardprovides the best sensitivity (100%) for C. difficile toxins A and B detection. The BioStar OIA rapid test missed seven positive stool specimens possibly due to failure to detect toxin B. ImmunoCard has slightly higher predictive values, shorter turnaround time and greater convenience compared to the Meridian EIA Assay. ImmunoCard may be cost effective not only in smaller laboratories, but also in high volume laboratories, when used on a STAT basis or single request.

  8. Isolation of Clostridium difficile and Detection of A and B Toxins Encoding Genes

    OpenAIRE

    Abbas Ali Imani Fooladi; Sadegh Rahmati; Jalil Falah Mehr Abadi; Raheleh Halabian; Hamid Sedighian; Mohammad Javad Soltanpour; Mohsen Rahimi

    2014-01-01

    Background: Clostridium difficile is the most important anaerobic, gram positive, spore forming bacillus which is known as a prevalent factor leading to antibiotic associated diarrheas and is the causative agent of pseudomembrane colitis. The role of this bacterium along with the over use of antibiotics have been proved to result in colitis. The major virulence factors of these bacteria are the A and B toxins. Objectives: The purpose of this study was to isolate C. difficile from sto...

  9. Saccharomyces boulardii Stimulates Intestinal Immunoglobulin A Immune Response to Clostridium difficile Toxin A in Mice

    Science.gov (United States)

    Qamar, Amir; Aboudola, Samer; Warny, Michel; Michetti, Pierre; Pothoulakis, Charalabos; LaMont, J. Thomas; Kelly, Ciarán P.

    2001-01-01

    Saccharomyces boulardii is a nonpathogenic yeast that protects against antibiotic-associated diarrhea and recurrent Clostridium difficile colitis. The administration of C. difficile toxoid A by gavage to S. boulardii-fed BALB/c mice caused a 1.8-fold increase in total small intestinal immunoglobulin A levels (P = 0.003) and a 4.4-fold increase in specific intestinal anti-toxin A levels (P boulardii-mediated protection against diarrheal illnesses. PMID:11254650

  10. Saccharomyces boulardii protease inhibits Clostridium difficile toxin A effects in the rat ileum.

    Science.gov (United States)

    Castagliuolo, I; LaMont, J T; Nikulasson, S T; Pothoulakis, C

    1996-01-01

    Saccharomyces boulardii, a nonpathogenic yeast, is effective in treating some patients with Clostridium difficile diarrhea and colitis. We have previously reported that S. boulardii inhibits rat ileal secretion in response to C. difficile toxin A possibly by releasing a protease that digests the intestinal receptor for this toxin (C. Pothoulakis, C. P. Kelly, M. A. Joshi, N. Gao, C. J. O'Keane, I. Castagliuolo, and J. T. LaMont, Gastroenterology 104: 1108-1115, 1993). The aim of this study was to purify and characterize this protease. S. boulardii protease was partially purified by gel filtration on Sephadex G-50 and octyl-Sepharose. The effect of S. boulardii protease on rat ileal secretion, epithelial permeability, and morphology in response to toxin A was examined in rat ileal loops in vivo. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified S. boulardii protease revealed a major band at 54 kDa. Pretreatment of rat ileal brush border (BB) membranes with partially purified protease reduced specific toxin A receptor binding (by 26%). Partially purified protease digested the toxin A molecule and significantly reduced its binding to BB membranes in vitro (by 42%). Preincubation of toxin A with S. boulardii protease inhibited ileal secretion (46% inhibition, P < 0.01), mannitol permeability (74% inhibition, P < 0.01), and histologic damage caused by toxin A. Thus, S. boulardii protease inhibits the intestinal effects of C. difficile toxin A by proteolysis of the toxin and inhibition of toxin A binding to its BB receptor. Our results may be relevant to the mechanism by which S. boulardii exerts its protective effects in C. difficile infection in humans. PMID:8945570

  11. Development of a recombinant toxin fragment vaccine for Clostridium difficile infection.

    Science.gov (United States)

    Karczewski, Jerzy; Zorman, Julie; Wang, Su; Miezeiewski, Matthew; Xie, Jinfu; Soring, Keri; Petrescu, Ioan; Rogers, Irene; Thiriot, David S; Cook, James C; Chamberlin, Mihaela; Xoconostle, Rachel F; Nahas, Debbie D; Joyce, Joseph G; Bodmer, Jean-Luc; Heinrichs, Jon H; Secore, Susan

    2014-05-19

    Clostridium difficile infection (CDI) is the major cause of antibiotic-associated diarrhea and pseudomembranous colitis, a disease associated with significant morbidity and mortality. The disease is mostly of nosocomial origin, with elderly patients undergoing anti-microbial therapy being particularly at risk. C. difficile produces two large toxins: Toxin A (TcdA) and Toxin B (TcdB). The two toxins act synergistically to damage and impair the colonic epithelium, and are primarily responsible for the pathogenesis associated with CDI. The feasibility of toxin-based vaccination against C. difficile is being vigorously investigated. A vaccine based on formaldehyde-inactivated Toxin A and Toxin B (toxoids) was reported to be safe and immunogenic in healthy volunteers and is now undergoing evaluation in clinical efficacy trials. In order to eliminate cytotoxic effects, a chemical inactivation step must be included in the manufacturing process of this toxin-based vaccine. In addition, the large-scale production of highly toxic antigens could be a challenging and costly process. Vaccines based on non-toxic fragments of genetically engineered versions of the toxins alleviate most of these limitations. We have evaluated a vaccine assembled from two recombinant fragments of TcdB and explored their potential as components of a novel experimental vaccine against CDI. Golden Syrian hamsters vaccinated with recombinant fragments of TcdB combined with full length TcdA (Toxoid A) developed high titer IgG responses and potent neutralizing antibody titers. We also show here that the recombinant vaccine protected animals against lethal challenge with C. difficile spores, with efficacy equivalent to the toxoid vaccine. The development of a two-segment recombinant vaccine could provide several advantages over toxoid TcdA/TcdB such as improvements in manufacturability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Bezlotoxumab: anti-toxin B monoclonal antibody to prevent recurrence of Clostridium difficile infection.

    Science.gov (United States)

    Villafuerte Gálvez, Javier A; Kelly, Ciarán P

    2017-07-01

    Clostridium difficile infection (CDI) is the most common nosocomial infection in the U.S. 25% of CDI patients go on to develop recurrent CDI (rCDI) following current standard of care (SOC) therapy, leading to morbidity, mortality and economic loss. The first passive immunotherapy drug targeting C.difficile toxin B (bezlotoxumab) has been approved recently by the FDA and EMA for prevention of rCDI. Areas covered: A body of key studies was selected and reviewed by the authors. The unmet needs in CDI care were ascertained with emphasis in rCDI, including the epidemiology, pathophysiology and current management. The current knowledge about the immune response to C. difficile toxins and how this knowledge led to the development and the clinical use of bezlotoxumab is described. Current and potential future competitors to the drug were examined. Expert commentary: A single 10 mg/kg intravenous infusion of bezlotoxumab has been shown to decrease rCDI by ~40% (absolute reduction ~10%) in patients being treated for primary CDI or rCDI with SOC antibiotics. Targeting C.difficile toxins by passive immunotherapy is a novel mechanism for prevention of C.difficile infection. Bezlotoxumab will be a valuable adjunctive therapy to reduce the burden of CDI.

  13. Effects of anti-inflammatory drugs on fever and neutrophilia induced by Clostridium difficile toxin B

    Directory of Open Access Journals (Sweden)

    R. A. Cardoso

    1996-01-01

    Full Text Available This study investigated the ability of Clostridium difficile toxin B, isolated from the VPI 10463 strain, to induce fever and neutrophilia in rats. Intravenous injection of toxin B (0.005–0.5 μg/kg evoked a dose-dependent increase in body temperature. The febrile response to 0.5 μg/kg of the toxin started in 2.5 h, peaked at 5 h, and subsided fully within 24 h. Toxin B also induced a dosedependent neutrophilia. Pretreatment with indomethacin (2 mg/kg, i.p. did not affect the neutrophilia induced by toxin B, but significantly reduced the febrile response measured 4 to 8 h after toxin B injection. Dexamethasone (0.5 mg/ kg also markedly diminished the febrile response induced by toxin B. These results show that Clostridium difficile toxin B induced a febrile response susceptible to inhibition by dexamethasone and indomethacin. Furthermore, they suggest that prostaglandins are not involved in the neutrophilia caused by this toxin.

  14. Isolation of Clostridium difficile and Detection of A and B Toxins Encoding Genes

    Directory of Open Access Journals (Sweden)

    Abbas Ali Imani Fooladi

    2014-02-01

    Full Text Available Background: Clostridium difficile is the most important anaerobic, gram positive, spore forming bacillus which is known as a prevalent factor leading to antibiotic associated diarrheas and is the causative agent of pseudomembrane colitis. The role of this bacterium along with the over use of antibiotics have been proved to result in colitis. The major virulence factors of these bacteria are the A and B toxins. Objectives: The purpose of this study was to isolate C. difficile from stool samples and detect A and B toxins encoding genes, in order toserve as a routine method for clinical diagnosis. Materials and Methods: Recognition of A and B toxins encoding genes by uniplex and multiplex PCR using two pairs of primers from 136 accumulated stool samples. Results: Results of the present study showed that out of 136 stool samples, three C. difficile were isolated and these strains contained A and B toxins encoding genes. Conclusions: It was concluded that although detection of C. difficile from stool samples based on PCR (polymerase chain reaction is expensive, yet this method is more sensitive and less time-consuming than culture methods and can be used as a clinical laboratory test.

  15. Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection?

    Directory of Open Access Journals (Sweden)

    Mark I. Garvey

    2017-12-01

    Full Text Available Abstract Background Diagnosis of C. difficile infection (CDI is controversial because of the many laboratory methods available and their lack of ability to distinguish between carriage, mild or severe disease. Here we describe whether a low C. difficile toxin B nucleic acid amplification test (NAAT cycle threshold (CT can predict toxin EIA, CDI severity and mortality. Methods A three-stage algorithm was employed for CDI testing, comprising a screening test for glutamate dehydrogenase (GDH, followed by a NAAT, then a toxin enzyme immunoassay (EIA. All diarrhoeal samples positive for GDH and NAAT between 2012 and 2016 were analysed. The performance of the NAAT CT value as a classifier of toxin EIA outcome was analysed using a ROC curve; patient mortality was compared to CTs and toxin EIA via linear regression models. Results A CT value ≤26 was associated with ≥72% toxin EIA positivity; applying a logistic regression model we demonstrated an association between low CT values and toxin EIA positivity. A CT value of ≤26 was significantly associated (p = 0.0262 with increased one month mortality, severe cases of CDI or failure of first line treatment. The ROC curve probabilities demonstrated a CT cut off value of 26.6. Discussions Here we demonstrate that a CT ≤26 indicates more severe CDI and is associated with higher mortality. Samples with a low CT value are often toxin EIA positive, questioning the need for this additional EIA test. Conclusions A CT ≤26 could be used to assess the potential for severity of CDI and guide patient treatment.

  16. Cannabidiol restores intestinal barrier dysfunction and inhibits the apoptotic process induced by Clostridium difficile toxin A in Caco-2 cells.

    Science.gov (United States)

    Gigli, Stefano; Seguella, Luisa; Pesce, Marcella; Bruzzese, Eugenia; D'Alessandro, Alessandra; Cuomo, Rosario; Steardo, Luca; Sarnelli, Giovanni; Esposito, Giuseppe

    2017-12-01

    Clostridium difficile toxin A is responsible for colonic damage observed in infected patients. Drugs able to restore Clostridium difficile toxin A-induced toxicity have the potential to improve the recovery of infected patients. Cannabidiol is a non-psychotropic component of Cannabis sativa, which has been demonstrated to protect enterocytes against chemical and/or inflammatory damage and to restore intestinal mucosa integrity. The purpose of this study was to evaluate (a) the anti-apoptotic effect and (b) the mechanisms by which cannabidiol protects mucosal integrity in Caco-2 cells exposed to Clostridium difficile toxin A. Caco-2 cells were exposed to Clostridium difficile toxin A (30 ng/ml), with or without cannabidiol (10 -7 -10 -9  M), in the presence of the specific antagonist AM251 (10 -7  M). Cytotoxicity assay, transepithelial electrical resistence measurements, immunofluorescence analysis and immunoblot analysis were performed in the different experimental conditions. Clostridium difficile toxin A significantly decreased Caco-2 cells' viability and reduced transepithelial electrical resistence values and RhoA guanosine triphosphate (GTP), bax, zonula occludens-1 and occludin protein expression, respectively. All these effects were significantly and concentration-dependently inhibited by cannabidiol, whose effects were completely abolished in the presence of the cannabinoid receptor type 1 (CB1) antagonist, AM251. Cannabidiol improved Clostridium difficile toxin A-induced damage in Caco-2 cells, by inhibiting the apoptotic process and restoring the intestinal barrier integrity, through the involvement of the CB1 receptor.

  17. Toxin Gene Analysis of a Variant Strain of Clostridium difficile That Causes Human Clinical Disease

    Science.gov (United States)

    Sambol, Susan P.; Merrigan, Michelle M.; Lyerly, David; Gerding, Dale N.; Johnson, Stuart

    2000-01-01

    A toxin variant strain of Clostridium difficile was isolated from two patients with C. difficile-associated disease (CDAD), one of whom died from extensive pseudomembranous colitis. This strain, identified by restriction endonuclease analysis (REA) as type CF2, was not detected by an immunoassay for C. difficile toxin A. Culture supernatants of CF2 failed to elicit significant enterotoxic activity in the rabbit ileal loop assay but did produce atypical cytopathic effects in cell culture assay. Southern hybridization, PCR amplification, and DNA sequence analyses were performed on the toxin A (tcdA) and toxin B (tcdB) genes of type CF2 isolate 5340. Type CF2 5340 tcdA exhibited a 1,821-bp truncation, due to three deletions in the 3′ end of the gene, and a point mutation in the 5′ end of the gene, resulting in a premature stop codon at tcdA position 139. Type CF2 5340 tcdB exhibited multiple nucleotide base substitutions in the 5′ end of the gene compared to tcdB of the standard toxigenic strain VPI 10463. Type CF2 5340 toxin gene nucleotide sequences and deduced amino acid sequences showed a strong resemblance to those of the previously described variant C. difficile strain 1470, a strain reported to have reduced pathogenicity and no association with clinical illness in humans. REA of strain 1470 identified this strain as a distinct type (CF1) within the same REA group as the closely related type CF2. A review of our clinical-isolate collection identified five additional patients infected with type CF2, three of whom had documented CDAD. PCR amplification of the 3′ end of tcdA demonstrated identical 1.8-kb deletions in all seven type CF2 isolates. REA type CF2 is a toxin variant strain of C. difficile that retains the ability to cause disease in humans but is not detected in clinical immunoassays for toxin A. PMID:10992443

  18. Saccharomyces boulardii Protease Inhibits the Effects of Clostridium difficile Toxins A and B in Human Colonic Mucosa

    Science.gov (United States)

    Castagliuolo, Ignazio; Riegler, Martin F.; Valenick, Leyla; LaMont, J. Thomas; Pothoulakis, Charalabos

    1999-01-01

    Saccharomyces boulardii is a nonpathogenic yeast used in the treatment of Clostridium difficile diarrhea and colitis. We have reported that S. boulardii inhibits C. difficile toxin A enteritis in rats by releasing a 54-kDa protease which digests the toxin A molecule and its brush border membrane (BBM) receptor (I. Castagliuolo, J. T. LaMont, S. T. Nikulasson, and C. Pothoulakis, Infect. Immun. 64:5225–5232, 1996). The aim of this study was to further evaluate the role of S. boulardii protease in preventing C. difficile toxin A enteritis in rat ileum and determine whether it protects human colonic mucosa from C. difficile toxins. A polyclonal rabbit antiserum raised against purified S. boulardii serine protease inhibited by 73% the proteolytic activity present in S. boulardii conditioned medium in vitro. The anti-protease immunoglobulin G (IgG) prevented the action of S. boulardii on toxin A-induced intestinal secretion and mucosal permeability to [3H]mannitol in rat ileal loops, while control rabbit IgG had no effect. The anti-protease IgG also prevented the effects of S. boulardii protease on digestion of toxins A and B and on binding of [3H]toxin A and [3H]toxin B to purified human colonic BBM. Purified S. boulardii protease reversed toxin A- and toxin B-induced inhibition of protein synthesis in human colonic (HT-29) cells. Furthermore, toxin A- and B-induced drops in transepithelial resistance in human colonic mucosa mounted in Ussing chambers were reversed by 60 and 68%, respectively, by preexposing the toxins to S. boulardii protease. We conclude that the protective effects of S. boulardii on C. difficile-induced inflammatory diarrhea in humans are due, at least in part, to proteolytic digestion of toxin A and B molecules by a secreted protease. PMID:9864230

  19. Positive predictive value of the immunoassay for Clostridium difficile toxin A and B detection at a private hospital.

    Science.gov (United States)

    Pérez-Topete, S E; Miranda-Aquino, T; Hernández-Portales, J A

    Clostridium difficile (C. difficile) is a Gram-positive bacillus that is a common cause of diarrhea in the hospital environment, with a documented incidence of up to 10%. There are different methods to detect it, but a widely used test in our environment is the immunoassay for toxins A and B. The aim of our study was to 1) estimate the positive predictive value of the immunoassay for the detection of the C. difficile toxins A and B, 2) to establish the incidence of C. difficile-associated diarrhea in the hospital, and 3) to know the most common associated factors. A diagnostic test accuracy study was conducted within the time frame of January 2010 to August 2013 at the Hospital Christus Muguerza® Alta Especialidad on patients with symptoms suggestive of C. difficile-associated diarrhea that had a positive immunoassay test and confirmation of C. difficile through colon biopsy and stool culture. The immunoassay for toxins A and B was performed in 360 patients. Fifty-five of the cases had positive results, 35 of which showed the presence of C. difficile. Incidence was 10.2% and the positive predictive value of the test for C. difficile toxins A and B was 0.64 (95% CI, 0.51-0.76). Previous antibiotic therapy (n=29) and proton pump inhibitor use (n=19) were the most common associated factors. C. difficile incidence in our environment is similar to that found in the literature reviewed, but the positive predictive value of the test for toxin A and B detection was low. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

  20. Neutralization of Clostridium difficile Toxin B Mediated by Engineered Lactobacilli That Produce Single-Domain Antibodies

    Science.gov (United States)

    Andersen, Kasper Krogh; Strokappe, Nika M.; Hultberg, Anna; Truusalu, Kai; Smidt, Imbi; Mikelsaar, Raik-Hiio; Mikelsaar, Marika; Verrips, Theo; Hammarström, Lennart

    2015-01-01

    Clostridium difficile is the primary cause of nosocomial antibiotic-associated diarrhea in the Western world. The major virulence factors of C. difficile are two exotoxins, toxin A (TcdA) and toxin B (TcdB), which cause extensive colonic inflammation and epithelial damage manifested by episodes of diarrhea. In this study, we explored the basis for an oral antitoxin strategy based on engineered Lactobacillus strains expressing TcdB-neutralizing antibody fragments in the gastrointestinal tract. Variable domain of heavy chain-only (VHH) antibodies were raised in llamas by immunization with the complete TcdB toxin. Four unique VHH fragments neutralizing TcdB in vitro were isolated. When these VHH fragments were expressed in either secreted or cell wall-anchored form in Lactobacillus paracasei BL23, they were able to neutralize the cytotoxic effect of the toxin in an in vitro cell-based assay. Prophylactic treatment with a combination of two strains of engineered L. paracasei BL23 expressing two neutralizing anti-TcdB VHH fragments (VHH-B2 and VHH-G3) delayed killing in a hamster protection model where the animals were challenged with spores of a TcdA− TcdB+ strain of C. difficile (P survived until the termination of the experiment at day 5 and showed either no damage or limited inflammation of the colonic mucosa despite having been colonized with C. difficile for up to 4 days. The protective effect in the hamster model suggests that the strategy could be explored as a supplement to existing therapies for patients. PMID:26573738

  1. Laboratory and Clinical features of EIA Toxin-positive and EIA Toxin-negative Community-acquired Clostridium difficile Infection.

    Science.gov (United States)

    Patel, Hiren; Randhawa, Jeewanjot; Nanavati, Sushant; Marton, L Randy; Baddoura, Walid J; DeBari, Vincent A

    2015-01-01

    Studies have described the clinical course of patients with Clostridium difficile infection (CDI) with positive enzyme immunoassay (EIA) for toxins A and B. Limited information is available for the patients with negative EIA but positive for the toxin B gene (TcdB) by the PCR. The aim of our study is to determine if there are any differences that exist among the clinical and laboratory parameters in the patients tested to be positive by EIA for toxin and those who were negative. This is a retrospective cohort study conducted in a 700-bed teaching hospital. We reviewed charts of the patients with presumptive CDI between January 2006 and July 2013. We divided these patients into two groups, EIA-positive and EIA-negative, based on result of EIA for toxins A and B and the requirement for a positive PCR analysis of the TcdB gene. The EIA-positive group had significantly higher white blood cell counts (p<0.001), with a significantly greater percentage of bands (p<0.0001). Albumin and total protein both exhibit significantly (p<0.0001, both comparisons) lower values in the EIA-positive group. Among clinical findings, the EIA-positive group had significantly longer length of hospital stay (p=0.010). These data suggest that an infection with an EIA-negative strain of C. difficile presents laboratory markers closer to those of healthy subjects and clinical features suggesting considerably less severe than infection with EIA-positive C. difficile. © 2015 by the Association of Clinical Scientists, Inc.

  2. Inhibition of Clostridium difficile toxin A and B by 1,2-cyclohexanedione modification of an arginine residue.

    Science.gov (United States)

    Balfanz, J; Rautenberg, P

    1989-12-29

    Toxin A (enterotoxin) and toxin B (cytotoxin) of Clostridium difficile were both inactivated by the arginine specific reagent 1,2-cyclohexanedione. Molecular stability during the inactivation process was demonstrated by SDS-PAGE analysis showing the same migration rates for modified and unmodified forms of the 230 kDa toxin A and of the 250 kDa toxin B. Cytotoxicity of both toxins as well as mouse lethality of the enterotoxin were drastically decreased as a result of the arginine modification. The reaction followed pseudo-first-order kinetics. Analysis of the data suggested that modification of a single arginine residue was sufficient to abolish the activity of both toxins.

  3. A two-stage algorithm for Clostridium difficile including PCR: can we replace the toxin EIA?

    Science.gov (United States)

    Orendi, J M; Monnery, D J; Manzoor, S; Hawkey, P M

    2012-01-01

    A two step, three-test algorithm for Clostridium difficile infection (CDI) was reviewed. Stool samples were tested by enzyme immunoassays for C. difficile common antigen glutamate dehydrogenase (G) and toxin A/B (T). Samples with discordant results were tested by polymerase chain reaction detecting the toxin B gene (P). The algorithm quickly identified patients with detectable toxin A/B, whereas a large group of patients excreting toxigenic C. difficile but with toxin A/B production below detection level (G(+)T(-)P(+)) was identified separately. The average white blood cell count in patients with a G(+)T(+) result was higher than in those with a G(+)T(-)P(+) result. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  4. A novel regulator controls Clostridium difficile sporulation, motility and toxin production.

    Science.gov (United States)

    Edwards, Adrianne N; Tamayo, Rita; McBride, Shonna M

    2016-06-01

    Clostridium difficile is an anaerobic pathogen that forms spores which promote survival in the environment and transmission to new hosts. The regulatory pathways by which C. difficile initiates spore formation are poorly understood. We identified two factors with limited similarity to the Rap sporulation proteins of other spore-forming bacteria. In this study, we show that disruption of the gene CD3668 reduces sporulation and increases toxin production and motility. This mutant was more virulent and exhibited increased toxin gene expression in the hamster model of infection. Based on these phenotypes, we have renamed this locus rstA, for regulator of sporulation and toxins. Our data demonstrate that RstA is a bifunctional protein that upregulates sporulation through an unidentified pathway and represses motility and toxin production by influencing sigD transcription. Conserved RstA orthologs are present in other pathogenic and industrial Clostridium species and may represent a key regulatory protein controlling clostridial sporulation. © 2016 John Wiley & Sons Ltd.

  5. C. difficile Infection

    Science.gov (United States)

    ... Patients Home / Digestive Health Topic / C. Difficile Infection C. Difficile Infection Basics Overview Diarrhea is a frequent ... that change the normal colon bacteria allowing the C. difficile bacteria to grow and produce its toxins. ...

  6. Evaluation of a focused virtual library of heterobifunctional ligands for Clostridium difficile toxins.

    Science.gov (United States)

    Sanhueza, Carlos A; Cartmell, Jonathan; El-Hawiet, Amr; Szpacenko, Adam; Kitova, Elena N; Daneshfar, Rambod; Klassen, John S; Lang, Dean E; Eugenio, Luiz; Ng, Kenneth K-S; Kitov, Pavel I; Bundle, David R

    2015-01-07

    A focused library of virtual heterobifunctional ligands was generated in silico and a set of ligands with recombined fragments was synthesized and evaluated for binding to Clostridium difficile toxins. The position of the trisaccharide fragment was used as a reference for filtering docked poses during virtual screening to match the trisaccharide ligand in a crystal structure. The peptoid, a diversity fragment probing the protein surface area adjacent to a known binding site, was generated by a multi-component Ugi reaction. Our approach combines modular fragment-based design with in silico screening of synthetically feasible compounds and lays the groundwork for future efforts in development of composite bifunctional ligands for large clostridial toxins.

  7. Expression of recombinant Clostridium difficile toxin A and B in Bacillus megaterium

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    Nie Weijia

    2008-11-01

    Full Text Available Abstract Background Major Clostridium difficile virulence factors are the exotoxins TcdA and TcdB. Due to the large size and poor stability of the proteins, the active recombinant TcdA and TcdB have been difficult to produce. Results The toxin genes tcdA and tcdB were amplified by PCR using chromosomal DNA from a toxigenic strain as a template, and cloned into a shuttle vector pHis1522. The sequences of both tcdA and tcdB genes in the vector have been verified by DNA sequencing. The constructs were transformed into B. megaterium protoplasts and the protein expression was controlled under a xylose promoter. The recombinant toxins (rTcdA and rTcdB were purified from bacterial crude extracts. Approximately 5 – 10 mg of highly purified recombinant toxins were obtained from one liter of bacterial culture. The resulting rTcdA and rTcdB had similar molecular masses to the native toxins, and their biological activities were found to be similar to their native counterparts after an extensive examination. Conclusion We have generated the full length and active recombinant TcdA and TcdB in Bacillus megaterium.

  8. The roles of host and pathogen factors and the innate immune response in the pathogenesis of Clostridium difficile infection

    Science.gov (United States)

    Sun, Xingmin; Hirota, Simon A.

    2014-01-01

    Clostridium difficile (C. difficile) is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of pseudomembranous colitis. The clinical manifestation of Clostridium difficile infection (CDI) is highly variable, from asymptomatic carriage, to mild self-limiting diarrhea, to the more severe pseudomembranous colitis. Furthermore, in extreme cases, colonic inflammation and tissue damage can lead to toxic megacolon, a condition requiring surgical intervention. C. difficile expresses two key virulence factors; the exotoxins, toxin A (TcdA) and toxin B (TcdB), which are glucosyltransferases that target host-cell monomeric GTPases. In addition, some hypervirulent strains produce a third toxin, binary toxin or C. difficile transferase (CDT), which may contribute to the pathogenesis of CDI. More recently, other factors such as surface layer proteins (SLPs) and flagellin have also been linked to the inflammatory responses observed in CDI. Although the adaptive immune response can influence the severity of CDI, the innate immune responses to C. difficile and its toxins play crucial roles in CDI onset, progression, and overall prognosis. Despite this, the innate immune responses in CDI have drawn relatively little attention from clinical researchers. Targeting these responses may prove useful clinically as adjuvant therapies, especially in refractory and/or recurrent CDI. This review will focus on recent advances in our understanding of how C. difficile and its toxins modulate innate immune responses that contribute to CDI pathogenesis. PMID:25242213

  9. Laboratory diagnosis of Clostridium difficile infection: Comparison of Techlab C. diff Quik Chek Complete, Xpert C. difficile, and multistep algorithmic approach.

    Science.gov (United States)

    Seo, Ja Young; Jeong, Ji Hun; Kim, Kyung Hee; Ahn, Jeong-Yeal; Park, Pil-Whan; Seo, Yiel-Hea

    2017-11-01

    Clostridium difficile is a major pathogen responsible for nosocomial infectious diarrhea. We explored optimal laboratory strategies for diagnosis of C. difficile infection (CDI) in our clinical settings, a 1400-bed tertiary care hospital. Using 191 fresh stool samples from adult patients, we evaluated the performance of Xpert C. difficile (Xpert CD), C. diff Quik Chek Complete (which simultaneously detects glutamate dehydrogenase [GDH] and C. difficile toxins [CDT]), toxigenic culture, and a two-step algorithm composed of GDH/CDT as a screening test and Xpert CD as a confirmatory test. Clostridium difficile was detected in 35 samples (18.3%), and all isolates were toxigenic strains. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of each assay for detecting CDI were as follows: Quik Chek Complete CDT (45.7%, 100%, 100%, 89.1%), Quik Chek Complete GDH (97.1%, 99.4%, 97.1%, 99.4%), Xpert CD (94.3%, 100%, 100%, 98.7%), and toxigenic culture (91.4%, 100%, 100%, 98.1%). A two-step algorithm performed identically with Xpert CD assay. Our data showed that most C. difficile isolates from adult patients were toxigenic. We demonstrated that a two-step algorithm based on GDH/CDT assay followed by Xpert CD assay as a confirmatory test was rapid, reliable, and cost effective for diagnosis of CDI in an adult patient setting with high prevalence of toxigenic C. difficile. © 2017 Wiley Periodicals, Inc.

  10. Binding kinetics of Clostridium difficile toxins A and B to intestinal brush border membranes from infant and adult hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Rolfe, R.D. (Texas Tech Univ. Health Sciences Center, Lubbock (USA))

    1991-04-01

    This study was undertaken to determine if the relative resistance of neonates and infants to Clostridium difficile-associated intestinal disease can be related to age-dependent differences in intestinal receptors for C. difficile toxins A and B. Brush border membranes (BBMs) from the small intestines of adult and infant hamsters were examined for their ability to bind radiolabeled toxins A and B. (125I)toxin A bound to both infant and adult hamster BBMs at physiological temperature, whereas (125I)toxin B did not bind to the BBMs under any of the conditions examined. The number of (125I)toxin A molecules bound at saturation was approximately 4 x 10(10) per micrograms of membrane protein for adult BBMs and 1 x 10(11) per micrograms of membrane protein for infant BBMs. Scatchard plot analysis suggested the presence of a single class of toxin A binding sites on both infant and adult hamster BBMs. Maximal binding capacity and Kd values were 0.63 pmol/mg of protein and 66.7 nM, respectively, for the infant BBMs, and 0.24 pmol/mg of protein and 27 nM, respectively, for the adult BBMs. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analyses of extracted BBM proteins revealed differences in the proteins of infant and adult BBMs. However, there were not any detectable differences in the protein bands which bound (125I)toxin A between infant and adult hamsters. The results from these investigations indicate that differences in the binding kinetics of toxins A and/or B to infant and adult hamster BBMs do not account for the observed differences in their susceptibility to C. difficile-associated intestinal disease.

  11. Binding kinetics of Clostridium difficile toxins A and B to intestinal brush border membranes from infant and adult hamsters

    International Nuclear Information System (INIS)

    Rolfe, R.D.

    1991-01-01

    This study was undertaken to determine if the relative resistance of neonates and infants to Clostridium difficile-associated intestinal disease can be related to age-dependent differences in intestinal receptors for C. difficile toxins A and B. Brush border membranes (BBMs) from the small intestines of adult and infant hamsters were examined for their ability to bind radiolabeled toxins A and B. [125I]toxin A bound to both infant and adult hamster BBMs at physiological temperature, whereas [125I]toxin B did not bind to the BBMs under any of the conditions examined. The number of [125I]toxin A molecules bound at saturation was approximately 4 x 10(10) per micrograms of membrane protein for adult BBMs and 1 x 10(11) per micrograms of membrane protein for infant BBMs. Scatchard plot analysis suggested the presence of a single class of toxin A binding sites on both infant and adult hamster BBMs. Maximal binding capacity and Kd values were 0.63 pmol/mg of protein and 66.7 nM, respectively, for the infant BBMs, and 0.24 pmol/mg of protein and 27 nM, respectively, for the adult BBMs. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analyses of extracted BBM proteins revealed differences in the proteins of infant and adult BBMs. However, there were not any detectable differences in the protein bands which bound [125I]toxin A between infant and adult hamsters. The results from these investigations indicate that differences in the binding kinetics of toxins A and/or B to infant and adult hamster BBMs do not account for the observed differences in their susceptibility to C. difficile-associated intestinal disease

  12. Diagnosis of Clostridium difficile-associated disease: examination of multiple algorithms using toxin EIA, glutamate dehydrogenase EIA and loop-mediated isothermal amplification.

    Science.gov (United States)

    Bamber, A I; Fitzsimmons, K; Cunniffe, J G; Beasor, C C; Mackintosh, C A; Hobbs, G

    2012-01-01

    The laboratory diagnosis of Clostridium difficile infection (CDI) needs to be accurate and timely to ensure optimal patient management, infection control and reliable surveillance. Three methods are evaluated using 810 consecutive stool samples against toxigenic culture: CDT TOX A/B Premier enzyme immunoassay (EIA) kit (Meridian Bioscience, Europe), Premier EIA for C. difficile glutamate dehydrogenase (GDH) (Meridian Bioscience, Europe) and the Illumigene kit (Meridian Bioscience, Europe), both individually and within combined testing algorithms. The study revealed that the CDT TOX A/B Premier EIA gave rise to false-positive and false-negative results and demonstrated poor sensitivity (56.47%), compared to Premier EIA for C. difficile GDH (97.65%), suggesting this GDH EIA can be a useful negative screening method. Results for the Illumigene assay alone showed sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of 91.57%, 98.07%, 99.03% and 84.44%, respectively. A two-stage algorithm using Premier EIA for C. difficile GDH/Illumigene assay yielded superior results compared with other testing algorithms (91.57%, 98.07%, 99.03% and 84.44%, respectively), mirroring the Illumigene performance. However, Illumigene is approximately half the cost of current polymerase chain reaction (PCR) methods, has a rapid turnaround time and requires no specialised skill base, making it an attractive alternative to assays such as the Xpert C. difficile assay (Cepheid, Sunnyvale, CA). A three-stage algorithm offered no improvement and would hamper workflow.

  13. Six rapid tests for direct detection of Clostridium difficile and its toxins in fecal samples compared with the fibroblast cytotoxicity assay.

    Science.gov (United States)

    Turgeon, David K; Novicki, Thomas J; Quick, John; Carlson, LaDonna; Miller, Pat; Ulness, Bruce; Cent, Anne; Ashley, Rhoda; Larson, Ann; Coyle, Marie; Limaye, Ajit P; Cookson, Brad T; Fritsche, Thomas R

    2003-02-01

    Clostridium difficile is one of the most frequent causes of nosocomial gastrointestinal disease. Risk factors include prior antibiotic therapy, bowel surgery, and the immunocompromised state. Direct fecal analysis for C. difficile toxin B by tissue culture cytotoxin B assay (CBA), while only 60 to 85% sensitive overall, is a common laboratory method. We have used 1,003 consecutive, nonduplicate fecal samples to compare six commercially available immunoassays (IA) for C. difficile detection with CBA: Prima System Clostridium difficile Tox A and VIDAS Clostridium difficile Tox A II, which detect C. difficile toxin A; Premier Cytoclone A/B and Techlab Clostridium difficile Tox A/B, which detect toxins A and B; and ImmunoCard Clostridium difficile and Triage Micro C. difficile panels, which detect toxin A and a species-specific antigen. For all tests, Triage antigen was most sensitive (89.1%; negative predictive value [NPV] = 98.7%) while ImmunoCard was most specific (99.7%; positive predictive value [PPV] = 95.0%). For toxin tests only, Prima System had the highest sensitivity (82.2%; NPV = 98.0%) while ImmunoCard had the highest specificity (99.7%; PPV = 95.0%). Hematopoietic stem cell transplant (HSCT) patients contributed 44.7% of all samples tested, and no significant differences in sensitivity or specificity were noted between HSCT and non-HSCT patients. IAs, while not as sensitive as direct fecal CBA, produce reasonable predictive values, especially when both antigen and toxin are detected. They also offer significant advantages over CBA in terms of turnaround time and ease of use.

  14. Clostridium difficile and Clostridium perfringens from wild carnivore species in Brazil.

    Science.gov (United States)

    Silva, Rodrigo Otávio Silveira; D'Elia, Mirella Lauria; Tostes Teixeira, Erika Procópio; Pereira, Pedro Lúcio Lithg; de Magalhães Soares, Danielle Ferreira; Cavalcanti, Álvaro Roberto; Kocuvan, Aleksander; Rupnik, Maja; Santos, André Luiz Quagliatto; Junior, Carlos Augusto Oliveira; Lobato, Francisco Carlos Faria

    2014-08-01

    Despite some case reports, the importance of Clostridium perfringens and Clostridium difficile for wild carnivores remains unclear. Thus, the objective of this study was to identify C. perfringens and C. difficile strains in stool samples from wild carnivore species in Brazil. A total of 34 stool samples were collected and subjected to C. perfringens and C. difficile isolation. Suggestive colonies of C. perfringens were then analyzed for genes encoding the major C. perfringens toxins (alpha, beta, epsilon and iota) and the beta-2 toxin (cpb2), enterotoxin (cpe) and NetB (netb) genes. C. difficile strains were analyzed by multiplex-PCR for toxins A (tcdA) and B (tcdB) and a binary toxin gene (cdtB) and also submitted to a PCR ribotyping. Unthawed aliquots of samples positive for C. difficile isolation were subjected to the detection of A/B toxins by a cytotoxicity assay (CTA). C. perfringens was isolated from 26 samples (76.5%), all of which were genotyped as type A. The netb gene was not detected, whereas the cpb2 and cpe genes were found in nine and three C. perfringens strains, respectively. C. difficile was isolated from two (5.9%) samples. A non-toxigenic strain was recovered from a non-diarrheic maned wolf (Chrysocyon brachyurus). Conversely, a toxigenic strain was found in the sample of a diarrheic ocelot (Leopardus pardallis); an unthawed stool sample was also positive for A/B toxins by CTA, indicating a diagnosis of C. difficile-associated diarrhea in this animal. The present work suggests that wild carnivore species could carry C. difficile strains and that they could be susceptible to C. difficile infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Intrinsic Toxin-Derived Peptides Destabilize and Inactivate Clostridium difficile TcdB

    Directory of Open Access Journals (Sweden)

    Jason L. Larabee

    2017-05-01

    Full Text Available Clostridium difficile infection (CDI is a major cause of hospital-associated, antibiotic-induced diarrhea, which is largely mediated by the production of two large multidomain clostridial toxins, TcdA and TcdB. Both toxins coordinate the action of specific domains to bind receptors, enter cells, and deliver a catalytic fragment into the cytosol. This results in GTPase inactivation, actin disassembly, and cytotoxicity. TcdB in particular has been shown to encode a region covering amino acids 1753 to 1851 that affects epitope exposure and cytotoxicity. Surprisingly, studies here show that several peptides derived from this region, which share the consensus sequence 1769NVFKGNTISDK1779, protect cells from the action of TcdB. One peptide, PepB2, forms multiple interactions with the carboxy-terminal region of TcdB, destabilizes TcdB structure, and disrupts cell binding. We further show that these effects require PepB2 to form a higher-order polymeric complex, a process that requires the central GN amino acid pair. These data suggest that TcdB1769–1779 interacts with repeat sequences in the proximal carboxy-terminal domain of TcdB (i.e., the CROP domain to alter the conformation of TcdB. Furthermore, these studies provide insights into TcdB structure and functions that can be exploited to inactivate this critical virulence factor and ameliorate the course of CDI.

  16. First report of Clostridium difficile NAP1/027 in a Mexican hospital.

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    Adrián Camacho-Ortiz

    Full Text Available Clostridium difficile NAP1/ribotype 027 is associated with severe disease and high mortality rates. Our aim was to determine the prevalence of NAP1/ribotype 027 among C. difficile isolates in a tertiary care hospital, and review the main clinical data.We included 106 stool samples from 106 patients. Samples were tested for A&B toxins and were cultured on CCFA agar. The genes tcdA, tcdB, tcdC, cdtA, and cdtB were amplified using PCR in clinical isolates. The tcdA 3'-end deletion analysis, PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE were also performed. Stool samples that were positive for culture were tested by the GeneXpert C. difficile assay. Clinical data were collected.Thirty-six patients tested positive for A&B toxins; and 22 patients had positive culture for C. difficile, 14 of which tested positive for the A&B toxins and all 22 patients tested positive by the GeneXpert C. difficile assay. Risk factors included an average hospital stay of 16.1 days prior to toxin detection, average antibiotic use for 16.2 days, and a median of 3 antibiotics used. The 30-day crude mortality rate was 8.4%. Six of the 22 patients died, and 3 of those deaths were directly attributed to C. difficile infection. The majority of isolates, 90.9% (20/22, carried genes tcdB, tcdA, cdtA, and cdtB; and these strains carried the corresponding downregulator gene tcdC, with an 18-bp deletion. PFGE was performed on 17 isolates, and one main pattern was observed. Analysis of the ribotyping data showed similar results.The above findings represent the clonal spread of C. difficile in our institution, which mainly includes the NAP1/027 strain. This is the first report of C. difficile ribotype NAP1/027 in Mexico.

  17. Adaptation of Clostridium difficile toxin A for use as a protein translocation system

    Energy Technology Data Exchange (ETDEWEB)

    Kern, Stephanie M. [Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202 (United States); Feig, Andrew L., E-mail: afeig@chem.wayne.edu [Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202 (United States)

    2011-02-25

    Research highlights: {yields} Catalytic domain of TcdA was replaced by a luciferase reporter. {yields} Each functional domain retains activity in the context of the fusion protein. {yields} We provide evidence that reporter proteins are delivered into vero cells. {yields} System releases cargo into the cytosol, providing a powerful new biotechnology tool. -- Abstract: A cellular delivery system is a useful biotechnology tool, with many possible applications. Two derivatives of Clostridium difficile toxin A (TcdA) have been constructed (GFP-TcdA and Luc-TcdA), by fusing reporter genes to functional domains of TcdA, and evaluated for their ability to translocate their cargo into mammalian cells. The cysteine protease and receptor binding domains of TcdA have been examined and found to be functional when expressed in the chimeric construct. Whereas GFP failed to internalize in the context of the TcdA fusion, significant cellular luciferase activity was detected in vero cell lysates after treatment with Luc-TcdA. Treatment with bafilomycin A1, which inhibits endosomal acidification, traps the luciferase activity within endosomes. To further understand these results, clarified lysates were subjected to molecular weight sieving, demonstrating that active luciferase was released from Luc-TcdA after translocation and internal processing.

  18. Adaptation of Clostridium difficile toxin A for use as a protein translocation system

    International Nuclear Information System (INIS)

    Kern, Stephanie M.; Feig, Andrew L.

    2011-01-01

    Research highlights: → Catalytic domain of TcdA was replaced by a luciferase reporter. → Each functional domain retains activity in the context of the fusion protein. → We provide evidence that reporter proteins are delivered into vero cells. → System releases cargo into the cytosol, providing a powerful new biotechnology tool. -- Abstract: A cellular delivery system is a useful biotechnology tool, with many possible applications. Two derivatives of Clostridium difficile toxin A (TcdA) have been constructed (GFP-TcdA and Luc-TcdA), by fusing reporter genes to functional domains of TcdA, and evaluated for their ability to translocate their cargo into mammalian cells. The cysteine protease and receptor binding domains of TcdA have been examined and found to be functional when expressed in the chimeric construct. Whereas GFP failed to internalize in the context of the TcdA fusion, significant cellular luciferase activity was detected in vero cell lysates after treatment with Luc-TcdA. Treatment with bafilomycin A1, which inhibits endosomal acidification, traps the luciferase activity within endosomes. To further understand these results, clarified lysates were subjected to molecular weight sieving, demonstrating that active luciferase was released from Luc-TcdA after translocation and internal processing.

  19. Genome-Based Comparison of Clostridioides difficile: Average Amino Acid Identity Analysis of Core Genomes.

    Science.gov (United States)

    Cabal, Adriana; Jun, Se-Ran; Jenjaroenpun, Piroon; Wanchai, Visanu; Nookaew, Intawat; Wongsurawat, Thidathip; Burgess, Mary J; Kothari, Atul; Wassenaar, Trudy M; Ussery, David W

    2018-02-14

    Infections due to Clostridioides difficile (previously known as Clostridium difficile) are a major problem in hospitals, where cases can be caused by community-acquired strains as well as by nosocomial spread. Whole genome sequences from clinical samples contain a lot of information but that needs to be analyzed and compared in such a way that the outcome is useful for clinicians or epidemiologists. Here, we compare 663 public available complete genome sequences of C. difficile using average amino acid identity (AAI) scores. This analysis revealed that most of these genomes (640, 96.5%) clearly belong to the same species, while the remaining 23 genomes produce four distinct clusters within the Clostridioides genus. The main C. difficile cluster can be further divided into sub-clusters, depending on the chosen cutoff. We demonstrate that MLST, either based on partial or full gene-length, results in biased estimates of genetic differences and does not capture the true degree of similarity or differences of complete genomes. Presence of genes coding for C. difficile toxins A and B (ToxA/B), as well as the binary C. difficile toxin (CDT), was deduced from their unique PfamA domain architectures. Out of the 663 C. difficile genomes, 535 (80.7%) contained at least one copy of ToxA or ToxB, while these genes were missing from 128 genomes. Although some clusters were enriched for toxin presence, these genes are variably present in a given genetic background. The CDT genes were found in 191 genomes, which were restricted to a few clusters only, and only one cluster lacked the toxin A/B genes consistently. A total of 310 genomes contained ToxA/B without CDT (47%). Further, published metagenomic data from stools were used to assess the presence of C. difficile sequences in blinded cases of C. difficile infection (CDI) and controls, to test if metagenomic analysis is sensitive enough to detect the pathogen, and to establish strain relationships between cases from the same

  20. Clostridium difficile in retail baskets, trolleys, conveyor belts, and plastic bags in Saudi Arabia.

    Science.gov (United States)

    Alqumber, Mohammed A

    2014-10-01

    To determine Clostridium difficile (C. difficile) prevalence on retail surfaces and shoppers plastic bags. From 20 June to 10 August 2011, in a cross-sectional epidemiological study, 17 supermarkets from 2 cities, Albaha and Altaif, Saudi Arabia were sampled. A total of 800 samples, which comprised 200 samples per surveyed surface, were studied. These included baskets, trolleys, conveyer belts, and outgoing shoppers' plastic bags. Clostridium difficile strains were isolated. The isolates were characterized using ribotyping and  polymerase chain reaction for the detection of toxin A (tcdA), toxin B (tcdB), binary toxin (cdtB), and toxin C (tcdC) genes. Susceptibility to antibiotics was determined on a Muller-Hinton agar with 5% sheep blood agar using E-tests. Overall, the C. difficile prevalence on sampled surfaces was 0.75%. The highest prevalence was found on retail baskets and trolleys, followed by plastic bags. A total of 5 different ribotypes were identified. Alterations in tcdC were detected in ribotype 027 and BT1. All the identified isolates were susceptible to vancomycin, but resistant to levofloxacin. In this study, C. difficile was present at a rate of 0.75% on supermarket surfaces. Spore disinfection of implicated surfaces may be necessary to control any community-acquired infections caused by this pathogen. 

  1. Molecular Characterization of Clostridium difficile Isolates in China From 2010 to 2015

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    Xiao-shu Liu

    2018-04-01

    Full Text Available Clostridium difficile infection (CDI has become a worldwide public health problem causing high mortality and a large disease burden. Molecular typing and analysis is important for surveillance and infection control of CDI. However, molecular characterization of C. difficile across China is extremely rare. Here, we report on the toxin profiles, molecular subtyping with multilocus sequence typing (MLST and PCR ribotyping, and epidemiological characteristics of 199 C. difficile isolates collected between 2010 through 2015 from 13 participating centers across China. We identified 35 STs and 27 ribotypes (RTs among the 199 C. difficile isolates: ST35 (15.58%, ST3 (15.08%, ST37 (12.06%, and RT017 (14.07%, RT001 (12.06%, RT012 (11.56% are the most prevalent. One isolate with ST1 and 8 isolates with ST 11 were identified. We identified a new ST in this study, denoted ST332. The toxin profile tcdA+tcdB+tcdC+tcdR+tcdE+CDT- (65.83% was the predominant profile. Furthermore, 11 isolates with positive binary toxin genes were discovered. According to the PCR ribotyping, one isolate with RT 027, and 6 isolates with RT 078 were confirmed. The epidemiological characteristics of C. difficile in China shows geographical differences, and both the toxin profile and molecular types exhibit great diversity across the different areas.

  2. A segment of 97 amino acids within the translocation domain of Clostridium difficile toxin B is essential for toxicity.

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    Yongrong Zhang

    Full Text Available Clostridium difficile toxin B (TcdB intoxicates target cells by glucosylating Rho GTPases. TcdB (269 kDa consists of at least 4 functional domains including a glucosyltransferase domain (GTD, a cysteine protease domain (CPD, a translocation domain (TD, and a receptor binding domain (RBD. The function and molecular mode of action of the TD, which is the largest segment of TcdB and comprises nearly 50% of the protein, remain largely unknown. Here we show that a 97-amino-acid segment (AA1756 - 1852, designated as ?97 or D97, located in the C-terminus of the TD and adjacent to the RBD, is essential for the cellular activity of TcdB. Deletion of this segment in TcdB (designated as TxB-D97, did not adversely alter toxin enzymatic activities or its cellular binding and uptake capacity. TxB-D97 bound to and entered cells in a manner similar to TcdB holotoxin. Both wild type and mutant toxins released their GTDs similarly in the presence of inositol hexakisphosphate (InsP6, and showed a similar glucosyltransferase activity in a cell-free glucosylating assay. Despite these similarities, the cytotoxic activity of TxB-D97 was reduced by more than 5 logs compared to wild type toxin, supported by the inability of TxB-D97 to glucosylate Rac1 of target cells. Moreover, the mutant toxin failed to elicit tumor necrosis factor alpha (TNF-α in macrophages, a process dependent on the glucosyltransferase activity of the toxin. Cellular fractionation of toxin-exposed cells revealed that TxB-D97 was unable to efficiently release the GTD into cytosol. Thereby, we conclude the 97-amino-acid region of the TD C-terminus of TcdB adjacent to the RBD, is essential for the toxicity of TcdB.

  3. Low sensitivity of fecal toxin A/B enzyme immunoassay for diagnosis of Clostridium difficile infection in immunocompromised patients.

    Science.gov (United States)

    Erb, S; Frei, R; Strandén, A M; Dangel, M; Tschudin-Sutter, S; Widmer, A F

    2015-11-01

    The optimal approach in laboratory diagnosis of Clostridium difficile infection (CDI) is still not well defined. Toxigenic culture (TC) or alternatively fecal toxin assay by cell cytotoxicity neutralization assay are considered to be the reference standard, but these methods are time-consuming and labor intensive. In many medical centers, diagnosis of CDI is therefore still based on fecal toxin A/B enzyme immunoassay (EIA) directly from stool alone, balancing cost and speed against limited diagnostic sensitivity. The aim of the study was to assess in which patient population the additional workload of TC is justified. All consecutive stool specimens submitted for diagnosis of suspected CDI between 2004 and 2011 at a tertiary-care center were examined by toxin EIA and TC. Clinical data of patients with established diagnosis of CDI were collected in a standardized case-report form. From 12,481 stool specimens submitted to the microbiologic laboratory, 480 (3.8%) fulfilled CDI criteria; 274 (57.1%) were diagnosed by toxin EIA; and an additional 206 (42.9%) were diagnosed by TC when toxin EIA was negative. Independent predictors for negative toxin EIA but positive TC were high-dose corticosteroids (odds ratio (OR) 2.97, 95% confidence interval (CI) 1.50-5.90, p 0.002), leukocytopenia <1000/μL (OR 2.52, 95% CI 1.22-5.23, p 0.013) and nonsevere CDI (OR 2.21, 95% CI 1.39-3.50, p 0.001). There was no difference in outcomes such as in-hospital mortality and recurrence between both groups. In conclusion, negative toxin EIA does not rule out CDI in immunocompromised patients in the setting of relevant clinical symptoms. Methods with improved sensitivity such as TC or PCR should be used, particularly in this patient population. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  4. C. difficile 630Δerm Spo0A regulates sporulation, but does not contribute to toxin production, by direct high-affinity binding to target DNA.

    Directory of Open Access Journals (Sweden)

    Katharina E Rosenbusch

    Full Text Available Clostridium difficile is a Gram positive, anaerobic bacterium that can form highly resistant endospores. The bacterium is the causative agent of C. difficile infection (CDI, for which the symptoms can range from a mild diarrhea to potentially fatal pseudomembranous colitis and toxic megacolon. Endospore formation in Firmicutes, including C. difficile, is governed by the key regulator for sporulation, Spo0A. In Bacillus subtilis, this transcription factor is also directly or indirectly involved in various other cellular processes. Here, we report that C. difficile Spo0A shows a high degree of similarity to the well characterized B. subtilis protein and recognizes a similar binding sequence. We find that the laboratory strain C. difficile 630Δerm contains an 18bp-duplication near the DNA-binding domain compared to its ancestral strain 630. In vitro binding assays using purified C-terminal DNA binding domain of the C. difficile Spo0A protein demonstrate direct binding to DNA upstream of spo0A and sigH, early sporulation genes and several other putative targets. In vitro binding assays suggest that the gene encoding the major clostridial toxin TcdB may be a direct target of Spo0A, but supernatant derived from a spo0A negative strain was no less toxic towards Vero cells than that obtained from a wild type strain, in contrast to previous reports. These results identify for the first time direct (putative targets of the Spo0A protein in C. difficile and make a positive effect of Spo0A on production of the large clostridial toxins unlikely.

  5. Shedding of Clostridium difficile PCR ribotype 078 by zoo animals, and report of an unstable metronidazole-resistant isolate from a zebra foal (Equus quagga burchellii).

    Science.gov (United States)

    Álvarez-Pérez, Sergio; Blanco, José L; Martínez-Nevado, Eva; Peláez, Teresa; Harmanus, Celine; Kuijper, Ed; García, Marta E

    2014-03-14

    Clostridium difficile is an emerging and potentially zoonotic pathogen, but its prevalence in most animal species, including exhibition animals, is currently unknown. In this study we assessed the prevalence of faecal shedding of C. difficile by zoo animals, and determined the ribotype, toxin profile and antimicrobial susceptibility of recovered isolates. A total of 200 samples from 40 animal species (36.5% of which came from plains zebra, Equus quagga burchellii) were analysed. C. difficile was isolated from 7 samples (3.5% of total), which came from the following animal species: chimpanzee (Pan troglodytes troglodytes), dwarf goat (Capra hircus), and Iberian ibex (Capra pyrenaica hispanica), with one positive sample each; and plains zebra, with 4 positive samples from 3 different individuals. Most recovered isolates (4/7, 57.1%) belonged to the epidemic PCR ribotype 078, produced toxins A and B, and had the genes encoding binary toxin (i.e. A(+)B(+)CDT(+) isolates). The remaining three isolates belonged to PCR ribotypes 039 (A(-)B(-)CDT(-)), 042 (A(+)B(+)CDT(-)) and 110 (A(-)B(+)CDT(-)). Regardless of their ribotype, all isolates displayed high-level resistance to the fluoroquinolones ciprofloxacin, enrofloxacin and levofloxacin. Some isolates were also resistant to meropenem and/or ertapenem. A ribotype 078 isolate recovered from a male zebra foal initially showed in vitro resistance to metronidazole (MIC ≥ 256 μg/ml), but lost that trait after subculturing on non-selective media. We conclude that zoo animals belonging to different species can carry ribotype 078 and other toxigenic strains of C. difficile showing resistance to antimicrobial compounds commonly used in veterinary and/or human medicine. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells from Intoxication

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    Leonie Schnell

    2016-07-01

    Full Text Available Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenylsemicarbazone (EGA has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT. Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria.

  7. Characterization of the SigD regulon of C. difficile and its positive control of toxin production through the regulation of tcdR.

    Directory of Open Access Journals (Sweden)

    Imane El Meouche

    Full Text Available Clostridium difficile intestinal disease is mediated largely by the actions of toxins A (TcdA and B (TcdB, whose production occurs after the initial steps of colonization involving different surface or flagellar proteins. In B. subtilis, the sigma factor SigD controls flagellar synthesis, motility, and vegetative autolysins. A homolog of SigD encoding gene is present in the C.difficile 630 genome. We constructed a sigD mutant in C. difficile 630 ∆erm to analyze the regulon of SigD using a global transcriptomic approach. A total of 103 genes were differentially expressed between the wild-type and the sigD mutant, including genes involved in motility, metabolism and regulation. In addition, the sigD mutant displayed decreased expression of genes involved in flagellar biosynthesis, and also of genes encoding TcdA and TcdB as well as TcdR, the positive regulator of the toxins. Genomic analysis and RACE-PCR experiments allowed us to characterize promoter sequences of direct target genes of SigD including tcdR and to identify the SigD consensus. We then established that SigD positively regulates toxin expression via direct control of tcdR transcription. Interestingly, the overexpression of FlgM, a putative anti-SigD factor, inhibited the positive regulation of motility and toxin synthesis by SigD. Thus, SigD appears to be the first positive regulator of the toxin synthesis in C. difficile.

  8. ICU-Onset Clostridium difficile infection in a university hospital in China: a prospective cohort study.

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    Xiaohui Wang

    Full Text Available A prospective study was conducted to investigate the incidence, clinical profiles and outcome of ICU-onset CDI in a 50-bed medical ICU at a university hospital in China. Stools were collected from patients who developed ICU-onset diarrhea and was screened for tcdA (toxin A gene and tcdB (toxin B gene by PCR. CDI cases were compared with the ICU-onset non-CDI diarrhea cases for demographics, comorbidities, potential risk factors, major laboratory findings and outcomes. Stool samples from CDI cases were subjected to C. difficile culture and C. difficile isolates were screened for tcdA, tcdB and the binary toxin genes (cdtA and cdtB using multiplex PCR. Strain typing of toxigenic C. difficile isolates was performed using multilocus sequence typing. There were 1,277 patients in the ICU during the study period and 124 (9.7% developed ICU-onset diarrhea, of which 31 patients had CDI. The incidence of ICU-onset CDI was 25.2 cases per 10,000 ICU days. ICU-onset CDI cases had similar features with ICU-onset non-CDI diarrhea cases including the use of proton pump inhibitors and antibacterial agents. The crude mortality rate of ICU-onset CDI was 22.6%, but the attributable mortality rate of ICU-onset CDI was only 3.2% here. Toxigenic C. difficile isolates were recovered from 28 out of the 31 patients with CDI. cdtA and cdtB were found in two strains. Seventeen STs including 11 new STs were identified. All of the 11 new STs were single-locus variants of known STs and the 17 STs identified here could be clustered into 3 clades. The incidence of ICU-onset CDI here is similar to those in Europe and North America, suggesting that CDI is likely to be a common problem in China. Toxigenic C. difficile here belonged to a variety of STs, which may represent a significant clonal expansion rather than the true clonal diversity.

  9. Prevalence of Clostridium difficile in raw beef, cow, sheep, goat, camel and buffalo meat in Iran.

    Science.gov (United States)

    Rahimi, Ebrahim; Jalali, Mohammad; Weese, J Scott

    2014-02-05

    Clostridium difficile has been shown to be a nosocomial pathogen associated with diarrhoea and pseudomembranous colitis in hospitalised patients and the infection is believed to be acquired nosocomially. Recent studies have shown the occurrence of C. difficile in food animals which may act as a source of infection to humans.The aim of this study was to determine the occurrence of C. difficile in retail raw beef, cow, sheep, goat, camel and buffalo meat in Iran. From April to October 2012, a total of 660 raw meat samples from beef, cow, sheep, goat, camel and buffalo were purchased from 49 butcheries in Isfahan and Khuzestan provinces, Iran, and were evaluated for the presence of C. difficile using a method including selective enrichment in C. difficile broth, subsequent alcohol shock-treatment and plating onto C. difficile selective medium. C. difficile isolates were tested for the presence of toxin genes and were typed using PCR ribotyping. In this study, 13 of 660 meat samples (2%) were contaminated with C. difficile. The highest prevalence of C. difficile was found in buffalo meat (9%), followed by goat meat (3.3%), beef meat (1.7%), cow (0.94%) and sheep meat (0.9%). Seven of the 13C. difficile strains (53.9%) were positive for tcdA, tcdB and cdtB toxin genes and were classified as ribotype 078. Four strains (30.8%) were positive tcdA, and tcdB, and one strain (7.7%) was possessed only tcdB. The remaining isolate was non-toxigenic. Susceptibilities of 13C. difficile isolates were determined for 11 antimicrobial drugs using the disk diffusion assay. Resistance to clindamycin, gentamycin, and nalidixic acid was the most common finding. To our knowledge, the present study is the first report of the isolation of C. difficile from raw buffalo meat. This study indicates the potential importance of food, including buffalo meat, as a source of transmission of C. difficile to humans.

  10. The Copenhagen Dependency Treebank (CDT)

    DEFF Research Database (Denmark)

    Høeg Müller, Henrik; Korzen, Iørn

    2014-01-01

    the fundamentals of how CDT is marked up with semantic relations in accordance with the dependency principles governing the annotation on the other levels of CDT. Specifically, focus will be on how Generative Lexicon (GL) theory has been incorporated into the unitary theoretical dependency framework of CDT....... An annotation scheme for lexical semantics has been designed so as to account for the lexico-semantic structure of complex NPs, and the four GL qualia also appear in some of the CDT discourse relation labels as a description of parallel semantic relations at this level....

  11. Extraction and sensitive detection of toxins A and B from the human pathogen Clostridium difficile in 40 seconds using microwave-accelerated metal-enhanced fluorescence.

    Directory of Open Access Journals (Sweden)

    Lovleen Tina Joshi

    Full Text Available Clostridium difficile is the primary cause of antibiotic associated diarrhea in humans and is a significant cause of morbidity and mortality. Thus the rapid and accurate identification of this pathogen in clinical samples, such as feces, is a key step in reducing the devastating impact of this disease. The bacterium produces two toxins, A and B, which are thought to be responsible for the majority of the pathology associated with the disease, although the relative contribution of each is currently a subject of debate. For this reason we have developed a rapid detection assay based on microwave-accelerated metal-enhanced fluorescence which is capable of detecting the presence of 10 bacteria in unprocessed human feces within 40 seconds. These promising results suggest that this prototype biosensor has the potential to be developed into a rapid, point of care, real time diagnostic assay for C. difficile.

  12. Open-label, dose escalation phase I study in healthy volunteers to evaluate the safety and pharmacokinetics of a human monoclonal antibody to Clostridium difficile toxin A.

    Science.gov (United States)

    Taylor, Claribel P; Tummala, Sanjeev; Molrine, Deborah; Davidson, Lisa; Farrell, Richard J; Lembo, Anthony; Hibberd, Patricia L; Lowy, Israel; Kelly, Ciaran P

    2008-06-25

    Recent data suggest that Clostridium difficile-associated diarrhea is becoming more severe and difficult to treat. Antibody responses to C. difficile toxin A are protective against symptomatic disease and recurrence. We examined the safety and pharmacokinetics (pk) of a novel neutralizing human monoclonal antibody against C. difficile toxin A (CDA1) in healthy adults. Five cohorts with 6 subjects each received a single intravenous infusion of CDA1 at escalating doses of 0.3, 1, 5, 10, and 20 mg/kg. Safety evaluations took place on days 1, 2, 3, 7, 14, 28, and 56 post-infusion. Samples for pk analysis were obtained before and after infusion, and at each safety evaluation. Serum CDA1 antibody concentrations and human anti-human antibody (HAHA) titers were measured with enzyme-linked immunosorbent assays. A noncompartmental model was used for pk analysis. Thirty subjects were enrolled. The median age was 27.5 yrs. There were no serious adverse events (AE) related to CDA1. Twenty-one of the 48 reported non-serious adverse events were possibly related to CDA1, and included transient blood pressure changes requiring no treatment, nasal congestion, headache, abdominal cramps, nausea, and self-limited diarrhea. Serum CDA1 concentrations increased with escalating doses: mean C(max) ranged from 6.82 microg/ml for the 0.3 mg/kg cohort to 511 microg/ml for the 20 mg/kg cohort. The geometric mean values of the half-life of CDA1 ranged between 25.3 and 31.8 days, and the volume of distribution approximated serum. No subject formed detectable HAHA titers. Administration of CDA1 as a single intravenous infusion was safe and well tolerated. C(max) increased proportionally with increasing doses. A randomized study of CDA1 in patients with C. difficile associated diarrhea is underway.

  13. Fecal Microbiota Transplantation: A Review of Emerging Indications Beyond Relapsing Clostridium difficile Toxin Colitis.

    Science.gov (United States)

    Jung Lee, Woo; Lattimer, Lakshmi D N; Stephen, Sindu; Borum, Marie L; Doman, David B

    2015-01-01

    The symbiotic relationship between gut microbiota and humans has been forged over many millennia. This relationship has evolved to establish an intimate partnership that we are only beginning to understand. Gut microbiota were once considered pathogenic, but the concept of gut microbiota and their influence in human health is undergoing a major paradigm shift, as there is mounting evidence of their impact in the homeostasis of intestinal development, metabolic activities, and the immune system. The disruption of microbiota has been associated with many gastrointestinal and nongastrointestinal diseases, and the reconstitution of balanced microbiota has been postulated as a potential therapeutic strategy. Fecal microbiota transplantation (FMT), a unique method to reestablish a sustained balance in the disrupted microbiota of diseased intestine, has demonstrated great success in the treatment of recurrent Clostridium difficile infection and has gained increasing acceptance in clinical use. The possibility of dysfunctional micro-biota playing a causative role in other gastrointestinal and nongas-trointestinal diseases, therefore, has also been raised, and there are an increasing number of studies supporting this hypothesis. FMT is emerging as a feasible therapeutic option for several diseases; however, its efficacy remains in question, given the lack of clinical trial data. Altering microbiota with FMT holds great promise, but much research is needed to further define FMT's therapeutic role and optimize the microbiota delivery system.

  14. Toxigenic Clostridium difficile PCR Ribotypes from Wastewater Treatment Plants in Southern Switzerland

    Science.gov (United States)

    Romano, Vincenza; Krovacek, Karel; Mauri, Federica; Demarta, Antonella; Dumontet, Stefano

    2012-01-01

    The occurrence of Clostridium difficile in nine wastewater treatment plants in the Ticino Canton (southern Switzerland) was investigated. The samples were collected from raw sewage influents and from treated effluents. Forty-seven out of 55 characterized C. difficile strains belonged to 13 different reference PCR ribotypes (009, 010, 014, 015, 039, 052, 053, 066, 070, 078, 101, 106, and 117), whereas 8 strains did not match any of those available in our libraries. The most frequently isolated ribotype (40%) was 078, isolated from six wastewater treatment plants, whereas ribotype 066, a toxigenic emerging ribotype isolated from patients admitted to hospitals in Europe and Switzerland, was isolated from the outgoing effluent of one plant. The majority of the isolates (85%) were toxigenic. Forty-nine percent of them produced toxin A, toxin B, and the binary toxin (toxigenic profile A+ B+ CDT+), whereas 51% showed the profile A+ B+ CDT−. Interestingly, eight ribotypes (010, 014, 015, 039, 066, 078, 101, and 106) were among the riboprofiles isolated from symptomatic patients admitted to the hospitals of the Ticino Canton in 2010. Despite the limitation of sampling, this study highlights that toxigenic ribotypes of C. difficile involved in human infections may occur in both incoming and outgoing biological wastewater treatment plants. Such a finding raises concern about the possible contamination of water bodies that receive wastewater treatment plant effluents and about the safe reuse of treated wastewater. PMID:22798376

  15. Novel Clostridium difficile Anti-Toxin (TcdA and TcdB Humanized Monoclonal Antibodies Demonstrate In Vitro Neutralization across a Broad Spectrum of Clinical Strains and In Vivo Potency in a Hamster Spore Challenge Model.

    Directory of Open Access Journals (Sweden)

    Hongyu Qiu

    Full Text Available Clostridium difficile (C. difficile infection (CDI is the main cause of nosocomial antibiotic-associated colitis and increased incidence of community-associated diarrhea in industrialized countries. At present, the primary treatment of CDI is antibiotic administration, which is effective but often associated with recurrence, especially in the elderly. Pathogenic strains produce enterotoxin, toxin A (TcdA, and cytotoxin, toxin B (TcdB, which are necessary for C. difficile induced diarrhea and gut pathological changes. Administration of anti-toxin antibodies provides an alternative approach to treat CDI, and has shown promising results in preclinical and clinical studies. In the current study, several humanized anti-TcdA and anti-TcdB monoclonal antibodies were generated and their protective potency was characterized in a hamster infection model. The humanized anti-TcdA (CANmAbA4 and anti-TcdB (CANmAbB4 and CANmAbB1 antibodies showed broad spectrum in vitro neutralization of toxins from clinical strains and neutralization in a mouse toxin challenge model. Moreover, co-administration of humanized antibodies (CANmAbA4 and CANmAbB4 cocktail provided a high level of protection in a dose dependent manner (85% versus 57% survival at day 22 for 50 mg/kg and 20 mg/kg doses, respectively in a hamster gastrointestinal infection (GI model. This study describes the protective effects conferred by novel neutralizing anti-toxin monoclonal antibodies against C. difficile toxins and their potential as therapeutic agents in treating CDI.

  16. Clostridium difficile toxin B inhibits the secretory response of human mast cell line-1 (HMC-1) cells stimulated with high free-Ca2+ and GTPγS

    International Nuclear Information System (INIS)

    Balletta, Andrea; Lorenz, Dorothea; Rummel, Andreas; Gerhard, Ralf; Bigalke, Hans; Wegner, Florian

    2015-01-01

    Clostridium difficile toxins A and B (TcdA and TcdB) belong to the class of large clostridial cytotoxins and inactivate by glucosylation some low molecular mass GTPases of the Rho-family (predominantly Rho, Rac and Cdc42), known as regulators of the actin cytoskeleton. TcdA and B also represent the main virulence factors of the anaerobic gram-positive bacterium that is the causal agent of pseudomembranous colitis. In our study, TcdB was chosen instead of TcdA for the well-known higher cytotoxic potency. Inactivation of Rho-family GTPases by this toxin in our experimental conditions induced morphological changes and reduction of electron-dense mast cell-specific granules in human mast cell line-1 (HMC-1) cells, but not cell death or permeabilisation of plasma-membranes. Previously reported patch-clamp dialysis experiments revealed that high intracellular free-Ca 2+ and GTPγS concentrations are capable of inducing exocytosis as indicated by significant membrane capacitance (C m ) increases in HMC-1 cells. In this study, we investigated the direct effects of TcdB upon HMC-1 cell “stimulated” C m increase, as well as on “constitutive” secretion of hexosaminidase and interleukin-16 (IL-16). Compared to untreated control cells, HMC-1 cells incubated with TcdB for 3–24 h exhibited a significant reduction of the mean absolute and relative C m increase in response to free-Ca 2+ and GTPγS suggesting an inhibition of secretory processes by TcdB. In conclusion, the HMC-1 cell line represents a suitable model for the study of direct effects of C. difficile toxins on human mast cell secretory activity

  17. Effects of Clostridium perfringens iota toxin in the small intestine of mice.

    Science.gov (United States)

    Redondo, Leandro M; Redondo, Enzo A; Dailoff, Gabriela C; Leiva, Carlos L; Díaz-Carrasco, Juan M; Bruzzone, Octavio A; Cangelosi, Adriana; Geoghegan, Patricia; Fernandez-Miyakawa, Mariano E

    2017-12-01

    Iota toxin is a binary toxin solely produced by Clostridium perfringens type E strains, and is structurally related to CDT from C. difficile and CST from C. spiroforme. As type E causes hemorrhagic enteritis in cattle, it is usually assumed that associated diseases are mediated by iota toxin, although evidence in this regard has not been provided. In the present report, iota toxin intestinal effects were evaluated in vivo using a mouse model. Histological damage was observed in ileal loops treated with purified iota toxin after 4 h of incubation. Luminal iota toxin induced fluid accumulation in the small intestine in a dose dependent manner, as determined by the enteropooling and the intestinal loop assays. None of these changes were observed in the large intestine. These results suggest that C. perfringens iota toxin alters intestinal permeability, predominantly by inducing necrosis and degenerative changes in the mucosal epithelium of the small intestine, as well as changes in intestinal motility. The obtained results suggest a central role for iota toxin in the pathogenesis of C. perfringens type E hemorrhagic enteritis, and contribute to remark the importance of clostridial binary toxins in digestive diseases. Published by Elsevier Ltd.

  18. Clostridium difficile Recombinant Toxin A Repeating Units as a Carrier Protein for Conjugate Vaccines: Studies of Pneumococcal Type 14, Escherichia coli K1, and Shigella flexneri Type 2a Polysaccharides in Mice

    Science.gov (United States)

    Pavliakova, Danka; Moncrief, J. Scott; Lyerly, David M.; Schiffman, Gerald; Bryla, Dolores A.; Robbins, John B.; Schneerson, Rachel

    2000-01-01

    Unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated rARU) from Clostridium difficile toxin A (CDTA) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, Shigella flexneri type 2a, and Escherichia coli K1. The yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of rARU with succinic anhydride. Conjugates, prepared with rARU or succinylated (rARUsucc), were administered to mice by a clinically relevant dosage and immunization scheme. All conjugates elicited high levels of serum immunoglobulin G both to the polysaccharides and to CDTA. Conjugate-induced anti-CDTA had neutralizing activity in vitro and protected mice challenged with CDTA, similar to the rARU alone. Conjugates prepared with succinylated rARU, therefore, have potential for serving both as effective carrier proteins for polysaccharides and for preventing enteric disease caused by C. difficile. PMID:10722615

  19. CDT and the Big Bang

    OpenAIRE

    Ambjorn, J.; Watabiki, Y.

    2017-01-01

    We describe a CDT-like model where breaking of W3 symmetry will lead to the emergence of time and subsequently of space. Surprisingly the simplest such models which lead to higher dimensional spacetimes are based on the four "magical" Jordan algebras of 3x3 Hermitian matrices with real, complex, quaternion and octonion entries, respectively. The simplest symmetry breaking leads to universes with spacetime dimensions 3, 4, 6, and 10.

  20. Hsp70 facilitates trans-membrane transport of bacterial ADP-ribosylating toxins into the cytosol of mammalian cells.

    Science.gov (United States)

    Ernst, Katharina; Schmid, Johannes; Beck, Matthias; Hägele, Marlen; Hohwieler, Meike; Hauff, Patricia; Ückert, Anna Katharina; Anastasia, Anna; Fauler, Michael; Jank, Thomas; Aktories, Klaus; Popoff, Michel R; Schiene-Fischer, Cordelia; Kleger, Alexander; Müller, Martin; Frick, Manfred; Barth, Holger

    2017-06-02

    Binary enterotoxins Clostridium (C.) botulinum C2 toxin, C. perfringens iota toxin and C. difficile toxin CDT are composed of a transport (B) and a separate non-linked enzyme (A) component. Their B-components mediate endocytic uptake into mammalian cells and subsequently transport of the A-components from acidic endosomes into the cytosol, where the latter ADP-ribosylate G-actin resulting in cell rounding and cell death causing clinical symptoms. Protein folding enzymes, including Hsp90 and peptidyl-prolyl cis/trans isomerases facilitate transport of the A-components across endosomal membranes. Here, we identified Hsp70 as a novel host cell factor specifically interacting with A-components of C2, iota and CDT toxins to facilitate their transport into the cell cytosol. Pharmacological Hsp70-inhibition specifically prevented pH-dependent trans-membrane transport of A-components into the cytosol thereby protecting living cells and stem cell-derived human miniguts from intoxication. Thus, Hsp70-inhibition might lead to development of novel therapeutic strategies to treat diseases associated with bacterial ADP-ribosylating toxins.

  1. The role of Campylobacter jejuni cytolethal distending toxin in gastroenteritis

    DEFF Research Database (Denmark)

    Mortensen, Ninell P; Schiellerup, Peter; Boisen, Nadia

    2011-01-01

    The role of Campylobacter jejuni cytolethal distending toxin (CDT) on clinical outcome after gastroenteritis was investigated. Clinical data, blood serum samples, and Campylobacter spp. isolated, from each of 30 patients were collected over a period of 6 months. The CDT encoding genes, cdt...

  2. Polyclonal Antibody Therapies for Clostridium difficile Infection

    Directory of Open Access Journals (Sweden)

    Michael R. Simon

    2014-10-01

    Full Text Available Clostridium difficile infection has emerged as a growing worldwide health problem. The colitis of Clostridium difficile infection results from the synergistic action of C. difficile secreted toxins A and B upon the colon mucosa. A human monoclonal IgG anti-toxin has demonstrated the ability in combination therapy to reduce mortality in C. difficile challenged hamsters. This antibody is currently in a clinical trial for the treatment of human Clostridium difficile infection. More than one group of investigators has considered using polyclonal bovine colostral antibodies to toxins A and B as an oral passive immunization. A significant proportion of the healthy human population possesses polyclonal antibodies to the Clostridium difficile toxins. We have demonstrated that polyclonal IgA derived from the pooled plasma of healthy donors possesses specificity to toxins A and B and can neutralize these toxins in a cell-based assay. This suggests that secretory IgA prepared from such pooled plasma IgA may be able to be used as an oral treatment for Clostridium difficile infection.

  3. CDT meets Horava-Lifshitz gravity

    International Nuclear Information System (INIS)

    Ambjorn, J.; Goerlich, A.; Jordan, S.; Jurkiewicz, J.; Loll, R.

    2010-01-01

    The theory of causal dynamical triangulations (CDT) attempts to define a nonperturbative theory of quantum gravity as a sum over spacetime geometries. One of the ingredients of the CDT framework is a global time foliation, which also plays a central role in the quantum gravity theory recently formulated by Horava. We show that the phase diagram of CDT bears a striking resemblance with the generic Lifshitz phase diagram appealed to by Horava. We argue that CDT might provide a unifying nonperturbative framework for anisotropic as well as isotropic theories of quantum gravity.

  4. TREATMENT OF CLOSTRIDIUM DIFFICILE- ASSOCIATED DISEASE

    Directory of Open Access Journals (Sweden)

    Snezana Antic-Mladenovic

    2007-04-01

    Full Text Available Clostridium difficile is a Gram-positive, spore-forming, anaerobic bacillus that is widely distributed in the environment, but is found as a part of a normal large bowel flora in approximately 3% of normal adults. C. difficile produces two protein exotoxins: toxin A and toxin B. Both toxins are responsible for causing the sings and symptoms of disease.C. difficile is now thought to be responsible for a spectrum of diseases, ranging from asymptomatic colonization to diarrhea of varying severity, life-threatening colitis, often as a consequence of long-term antibiotic exposure. This spectrum has become known as C. difficile-associated disease (CDAD.Treatment of Clostridium difficile-associated disease demand administration of effi-cient antibiotics (vancomycin, metronidazole, anion exchange resins and probiotics (Lactobacillus spp., Saccharomyces boulardii.

  5. A multiplex, internally controlled real-time PCR assay for detection of toxigenic Clostridium difficile and identification of hypervirulent strain 027/ST-1

    DEFF Research Database (Denmark)

    Hoegh, A M; Nielsen, J B; Lester, A

    2012-01-01

    The purpose of this study was to validate a multiplex real-time PCR assay capable of detecting toxigenic Clostridium difficile and simultaneously identifying C. difficile ribotype 027/ST-1 by targeting the toxin genes tcdA, tcdB and cdtA in one reaction and in a separate reaction identifying the Δ...... to confirm the correct identification of the Δ117 deletion in tcdC and C. difficile ribotype 027/ST-1, respectively. The PCR assay displayed a sensitivity, specificity, PPV and NPV of 99.0%, 97.4%, 87.4% and 99.8%, respectively, compared to toxigenic culture on 665 samples evaluable both by PCR and culture....... Sequencing of tcdC, ribotyping and MLST of cultured isolates validated the genotyping assay and confirmed the ability of the assay to correctly identify C. difficile ribotype 027/ST-1 in our current epidemiological setting. We describe the use of a combination of two separate PCR assays for sensitive...

  6. Clostridium difficile infection : epidemiology, complications and recurrences

    NARCIS (Netherlands)

    Bauer, Martijn Philippe

    2014-01-01

    Clostridium difficile is a spore-forming bacterium, the toxin-producing strains of which cause colitis. Risk factors are antibiotics, advanced age and severe comorbidity. C. difficile infection (CDI) has been regarded as mostly a hospital-acquired infection. Preventing relapses is considered the

  7. Clostridium difficile infection: molecular pathogenesis and novel therapeutics

    Science.gov (United States)

    Rineh, Ardeshir; Kelso, Michael J; Vatansever, Fatma; Tegos, George P; Hamblin, Michael R

    2015-01-01

    The Gram-positive anaerobic bacterium Clostridium difficile produces toxins A and B, which can cause a spectrum of diseases from pseudomembranous colitis to C. difficile-associated diarrhea. A limited number of C. difficile strains also produce a binary toxin that exhibits ADP ribosyltransferase activity. Here, the structure and the mechanism of action of these toxins as well as their role in disease are reviewed. Nosocomial C. difficile infection is often contracted in hospital when patients treated with antibiotics suffer a disturbance in normal gut microflora. C. difficile spores can persist on dry, inanimate surface for months. Metronidazole and oral vancomycin are clinically used for treatment of C. difficile infection but clinical failure and concern about promotion of resistance are motivating the search for novel non-antibiotic therapeutics. Methods for controlling both toxins and spores, replacing gut microflora by probiotics or fecal transplant, and killing bacteria in the anaerobic gut by photodynamic therapy are discussed. PMID:24410618

  8. Molecular epidemiology and antimicrobial susceptibility of Clostridium difficile isolated from the Chinese People’s Liberation Army General Hospital in China

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2018-02-01

    Full Text Available Clostridium difficile is a Gram-positive, spore-forming obligate anaerobe responsible for antibiotic-associated diarrhoea. Its virulence is associated with the production of endotoxins A and B and endospores, which can cause symptoms, such as diarrhoea, toxic megacolon, and pseudomembranous colitis. Given the increasing elderly population and the well-recognized problem of over-prescribing of broad-spectrum antibiotics, it is critical to have an understanding of molecular epidemiology and antimicrobial susceptibility in China. This study analyzed the toxin types and multilocus sequence typing (MLST results of 74 clinical isolates of C. difficile after the glutamate dehydrogenase (GDH screening test and anaerobic culture. The minimum inhibitory concentrations (MICs of four different antibiotics were determined for all of the isolates, and the bacterial resistance mechanisms were investigated. Sixty-five strains (75% were toxigenic, including 54 tcdA-positive, tcdB-positive, and cdtA/cdtB-negative strains (A+B+CDT− and nine A−B+CDT− strains. Eleven strains (14.9% were non-toxigenic. All clinical isolates were classified into 26 MLST genotypes, with the predominant type being ST-54 (18.9%. All isolates were susceptible to vancomycin. The tetracycline, clindamycin, and levofloxacin resistance rates were 1.4%, 36.5%, and 20.3%, respectively. The expression of tet(M, erm(B, and mutations of gyrA and/or gyrB were observed in the tetracycline-, clindamycin-, and levofloxacin-resistant isolates, respectively.

  9. Clostridium difficile and C. difficile Toxin Testing

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... antibiotic therapy Sample Required? A fresh or refrigerated liquid or unformed stool sample that has not been ...

  10. Clinical features of Clostridium difficile infection and molecular characterization of the isolated strains in a cohort of Danish hospitalized patients

    DEFF Research Database (Denmark)

    Søes, Lillian Marie; Brock, Inger; Persson, Søren

    2012-01-01

    The purpose of this study was to compare clinical features of Clostridium difficile infection (CDI) to toxin gene profiles of the strains isolated from Danish hospitalized patients. C. difficile isolates were characterized by PCR based molecular typing methods including toxin gene profiling...... A and B compared to patients infected by C. difficile harbouring only toxin A and B. In conclusion, infection by C. difficile harbouring genes encoding both toxin A, toxin B and the binary toxin were associated with hospital acquisition, higher leukocyte counts and severe clinical disease....

  11. Clostridium difficile – From Colonization to Infection

    Science.gov (United States)

    Schäffler, Holger; Breitrück, Anne

    2018-01-01

    Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI. PMID:29692762

  12. Cytolethal Distending Toxin Demonstrates Genotoxic Activity in a Yeast Model

    OpenAIRE

    Hassane, Duane C.; Lee, Robert B.; Mendenhall, Michael D.; Pickett, Carol L.

    2001-01-01

    Cytolethal distending toxins (CDTs) are multisubunit proteins produced by a variety of bacterial pathogens that cause enlargement, cell cycle arrest, and apoptosis in mammalian cells. While their function remains uncertain, recent studies suggest that they can act as intracellular DNases in mammalian cells. Here we establish a novel yeast model for understanding CDT-associated disease. Expression of the CdtB subunit in yeast causes a G2/M arrest, as seen in mammalian cells. CdtB toxicity is n...

  13. Trees and spatial topology change in CDT

    DEFF Research Database (Denmark)

    Ambjorn, Jan; Budd, Timothy George

    2013-01-01

    Generalized causal dynamical triangulations (generalized CDT) is a model of two-dimensional quantum gravity in which a limited number of spatial topology changes is allowed to occur. We solve the model at the discretized level using bijections between quadrangulations and trees. In the continuum...

  14. The cytolethal distending toxin contributes to microbial virulence and disease pathogenesis by acting as a tri-perditious toxin

    Directory of Open Access Journals (Sweden)

    Monika D Scuron

    2016-12-01

    Full Text Available This review summarizes the current status and recent advances in our understanding of the role that the cytolethal distending toxin (Cdt plays as a virulence factor in promoting disease by toxin-producing pathogens. A major focus of this review is on the relationship between structure and function of the individual subunits that comprise the AB2 Cdt holotoxin. In particular, we concentrate on the molecular mechanisms that characterize this toxin and which account for the ability of Cdt to intoxicate multiple cell types by utilizing a ubiquitous binding partner on the cell membrane. Furthermore, we propose a paradigm shift for the molecular mode of action by which the active Cdt subunit, CdtB, is able to block a key signaling cascade and thereby lead to outcomes based upon programming and the role of the phosphatidylinositol 3-kinase (PI-3K in a variety of cells. Based upon the collective Cdt literature, we now propose that Cdt is a unique and potent virulence factor capable of acting as a tri-perditious toxin that impairs host defenses by: 1 disrupting epithelial barriers; 2 suppressing acquired immunity; 3 promoting pro-inflammatory responses. Thus Cdt plays a key role in facilitating the early stages of infection and the later stages of disease progression by contributing to persistence and impairing host elimination.

  15. The HtrA-Like Protease CD3284 Modulates Virulence of Clostridium difficile

    NARCIS (Netherlands)

    Bakker, Dennis; Buckley, Anthony M.; de Jong, Anne; van Winden, Vincent J. C.; Verhoeks, Joost P. A.; Kuipers, Oscar P.; Douce, Gillian R.; Kuijper, Ed J.; Smits, Wiep Klaas; Corver, Jeroen

    2014-01-01

    In the past decade, Clostridium difficile has emerged as an important gut pathogen. Symptoms of C. difficile infection range from mild diarrhea to pseudomembranous colitis. Besides the two main virulence factors toxin A and toxin B, other virulence factors are likely to play a role in the

  16. Molecular characterization and antimicrobial resistance of strains isolated of Clostridium difficile from Hospital Mexico of Costa Rica in the period October 2010 - August 2012

    International Nuclear Information System (INIS)

    Montoya Ramirez, Monica

    2014-01-01

    Clostridium difficile has been Gram positive anaerobic bacillus producer of spores and recognized as the primary pathogen involved in nosocomial diarrhea in adults. Two toxins are produced: A and B, responsible for the symptoms present in patients with diseases associated to C. difficile (EACD) and regulated by the tcdC gene. Some variants also have had a binary toxin and changes in the regulatory gene, it is believed that these may lead to the overproduction of toxins and the consequent emergence of hypervirulent strains. The hypervirulent NAP1 was identified for the first time in Latin America (in addition to other traditional pulsotypes and other native), in the years 2008-2009 during the outbreak of nosocomial C. difficile diarrhea occurred in the Hospital San Juan de Dios in Costa Rica. In order to know whether this variant NAP1 or other pulsotypes are found present in other hospitals, C. difficile isolates obtained from patients in Hospital Mexico of Costa Rica were studied in the period October 2010-August 2012, in order to investigate molecularly by PCR toxins that are produced. Pulsotypes that belong are determined by pulsed-field electrophoresis, besides the minimum inhibitory concentration of ciprofloxacin, clindamycin, metronidazole, moxifloxacia, rifampin and vancomycin through the E-test technique. 56 strains isolates were analyzed in culture and identified as C. difficile by detection the tpi gene in the Hospital Mexico. The strains have had higher resistance to ciprofloxacin and clindamycin, 100% and 95%, respectively, clindamycin is the most related with associated diarrhea to antibiotic. In addition, significant percentages of resistance to moxifloxacin (43%) are obtained and rifampacin (43%) and all strains were sensitive to metronidazole and vancomycin. On the other hand, seven different patterns of PCR according to the locus SWAP were obtained, being the most frequent (58%, 33 strains) which corresponds to tcdA+, tcdB+, cdtB- and tcdC+ deletion

  17. Controversies Surrounding Clostridium difficile Infection in Infants and Young Children

    Directory of Open Access Journals (Sweden)

    Maribeth R. Nicholson

    2014-06-01

    Full Text Available Clostridium difficile is a frequent cause of antibiotic-associated diarrhea in adults and older children. However, as many as 80% of infants can be asymptomatically colonized. The reasons for this have not been well established but are believed to be due to differences in toxin receptors or toxin internalization. Determining which children who test positive for C. difficile warrant treatment is exceedingly difficult, especially in the setting of increased rates of detection and the rising risk of disease in children lacking classic risk factors for C. difficile.

  18. Clostridium Difficile Infections

    Science.gov (United States)

    Clostridium difficile (C. difficile) is a bacterium that causes diarrhea and more serious intestinal conditions such as colitis. Symptoms include Watery ... Loss of appetite Nausea Abdominal pain or tenderness C. difficile is more common in people who need ...

  19. Clostridium difficile

    African Journals Online (AJOL)

    and colitis and was identified as the cause of antibiotic associated ... antibiotic use. C. difficile is acquired by the faecal-oral route; the bacterial spores are not destroyed by gastric acid, enabling them to reach the intestines. The development of ... samples of soil, chicken faeces and water [2], highlighting the potential for ...

  20. Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era.

    Science.gov (United States)

    Polage, Christopher R; Gyorke, Clare E; Kennedy, Michael A; Leslie, Jhansi L; Chin, David L; Wang, Susan; Nguyen, Hien H; Huang, Bin; Tang, Yi-Wei; Lee, Lenora W; Kim, Kyoungmi; Taylor, Sandra; Romano, Patrick S; Panacek, Edward A; Goodell, Parker B; Solnick, Jay V; Cohen, Stuart H

    2015-11-01

    Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision making and public health reporting. Molecular tests are increasingly used to diagnose C difficile infection (CDI), but many molecular test-positive patients lack toxins that historically defined disease, making it unclear if they need treatment. To determine the natural history and need for treatment of patients who are toxin immunoassay negative and polymerase chain reaction (PCR) positive (Tox-/PCR+) for CDI. Prospective observational cohort study at a single academic medical center among 1416 hospitalized adults tested for C difficile toxins 72 hours or longer after admission between December 1, 2010, and October 20, 2012. The analysis was conducted in stages with revisions from April 27, 2013, to January 13, 2015. Patients undergoing C difficile testing were grouped by US Food and Drug Administration-approved toxin and PCR tests as Tox+/PCR+, Tox-/PCR+, or Tox-/PCR-. Toxin results were reported clinically. Polymerase chain reaction results were not reported. The main study outcomes were duration of diarrhea during up to 14 days of treatment, rate of CDI-related complications (ie, colectomy, megacolon, or intensive care unit care) and CDI-related death within 30 days. Twenty-one percent (293 of 1416) of hospitalized adults tested for C difficile were positive by PCR, but 44.7% (131 of 293) had toxins detected by the clinical toxin test. At baseline, Tox-/PCR+ patients had lower C difficile bacterial load and less antibiotic exposure, fecal inflammation, and diarrhea than Tox+/PCR+ patients (P difficile by either method. Exclusive reliance on molecular tests for CDI diagnosis without tests for toxins or host response is likely to result in overdiagnosis, overtreatment, and increased health care costs.

  1. The Biology of the Cytolethal Distending Toxins

    Directory of Open Access Journals (Sweden)

    Teresa Frisan

    2011-03-01

    Full Text Available The cytolethal distending toxins (CDTs, produced by a variety of Gram-negative pathogenic bacteria, are the first bacterial genotoxins described, since they cause DNA damage in the target cells. CDT is an A-B2 toxin, where the CdtA and CdtC subunits are required to mediate the binding on the surface of the target cells, allowing internalization of the active CdtB subunit, which is functionally homologous to the mammalian deoxyribonuclease I. The nature of the surface receptor is still poorly characterized, however binding of CDT requires intact lipid rafts, and its internalization occurs via dynamin-dependent endocytosis. The toxin is retrograde transported through the Golgi complex and the endoplasmic reticulum, and subsequently translocated into the nuclear compartment, where it exerts the toxic activity. Cellular intoxication induces DNA damage and activation of the DNA damage responses, which results in arrest of the target cells in the G1 and/or G2 phases of the cell cycle and activation of DNA repair mechanisms. Cells that fail to repair the damage will senesce or undergo apoptosis. This review will focus on the well-characterized aspects of the CDT biology and discuss the questions that still remain unanswered.

  2. The mechanism of Jurkat cells apoptosis induced by Aggregatibacter actinomycetemcomitans cytolethal distending toxin.

    Science.gov (United States)

    Chen, Hui-Ping; Li, Lu; Chen, Xu; Yang, Mi-Fang; Ye, Yu; Wang, Xiao-Qian; Xu, Yan

    2017-06-01

    Cytolethal distending toxin (CDT) which is produced by Aggregatibacter actinomycetemcomitans causes apoptosis in lymphocytes. But the specific mechanism is not clear. The aim of our research was to investigate the effect and mechanism during this process. The wild-type CdtA, CdtB, CdtC (CdtA W , CdtB W , CdtC W ) and mutant CdtB (CdtB M ) were expressed and purified respectively and the purity of each subunit was examined by BandScan software. And the type I deoxyribonuclease and PI-3,4,5-triphosphate (PI-3,4,5-P3, PIP3) phosphatase activity were detected by DNA agarose gel electrophoresis and enzyme-linked immunosorbent assay respectively. The cell apoptosis rates were analyzed by flow cytometry. The morphological changes of apoptosis cells were observed by confocal laser scanning microscopy. The protein expression of Bax and Bcl-2 was examined by western blot. Differentially expressed apoptosis-related proteins were identified based on isobaric tags for relative and absolute quantitation technology. In the present study we found that: (i) recombinant wild-type CdtA, CdtB and CdtC (CdtA W , CdtB W , CdtC W ) and mutant CdtB (CdtB M ) were correctly expressed and the purity of each protein was higher than 80%, (ii) the average apoptosis rate in wild-type CDT (CDT W ) treated groups was 50.54%, which was significantly higher than the controls (4.71%) and mutant CDT (CDT M ) treated groups (5.58%) (p apoptosis were observed in CDT W treated cells, (iv) the expression of Bax protein was significantly increased in CDT W treated cells, while Bcl-2 protein expression was significantly decreased, (v) 17 apoptosis-related proteins were expressed differentially, among which 10 proteins (SMNDC1, TNFRSF10B, UBE2I, ITM2A, CASP3, P53, EIF1, TCF3, HMGN5, CASP8) were up-regulated and 7 proteins (RRM2, TPX2, KIF11, NUCKS1, TOP2A, XRCC1, PTPLAD1, RRM2) were down-regulated, (vi) one possible apoptotic pathway [Ubc9 (UBE2I)/P53/DR5 (TNFRSF10B)/Caspase-8 (CASP8)/ Caspase-3 (CASP3

  3. Comparison of Diagnostic Algorithms for Detecting Toxigenic Clostridium difficile in Routine Practice at a Tertiary Referral Hospital in Korea.

    Science.gov (United States)

    Moon, Hee-Won; Kim, Hyeong Nyeon; Hur, Mina; Shim, Hee Sook; Kim, Heejung; Yun, Yeo-Min

    2016-01-01

    Since every single test has some limitations for detecting toxigenic Clostridium difficile, multistep algorithms are recommended. This study aimed to compare the current, representative diagnostic algorithms for detecting toxigenic C. difficile, using VIDAS C. difficile toxin A&B (toxin ELFA), VIDAS C. difficile GDH (GDH ELFA, bioMérieux, Marcy-l'Etoile, France), and Xpert C. difficile (Cepheid, Sunnyvale, California, USA). In 271 consecutive stool samples, toxigenic culture, toxin ELFA, GDH ELFA, and Xpert C. difficile were performed. We simulated two algorithms: screening by GDH ELFA and confirmation by Xpert C. difficile (GDH + Xpert) and combined algorithm of GDH ELFA, toxin ELFA, and Xpert C. difficile (GDH + Toxin + Xpert). The performance of each assay and algorithm was assessed. The agreement of Xpert C. difficile and two algorithms (GDH + Xpert and GDH+ Toxin + Xpert) with toxigenic culture were strong (Kappa, 0.848, 0.857, and 0.868, respectively). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of algorithms (GDH + Xpert and GDH + Toxin + Xpert) were 96.7%, 95.8%, 85.0%, 98.1%, and 94.5%, 95.8%, 82.3%, 98.5%, respectively. There were no significant differences between Xpert C. difficile and two algorithms in sensitivity, specificity, PPV and NPV. The performances of both algorithms for detecting toxigenic C. difficile were comparable to that of Xpert C. difficile. Either algorithm would be useful in clinical laboratories and can be optimized in the diagnostic workflow of C. difficile depending on costs, test volume, and clinical needs.

  4. Cytolethal Distending Toxin Enhances Radiosensitivity in Prostate Cancer Cells by Regulating Autophagy

    Directory of Open Access Journals (Sweden)

    Hwai-Jeng Lin

    2017-06-01

    Full Text Available Cytolethal distending toxin (CDT produced by Campylobacter jejuni contains three subunits: CdtA, CdtB, and CdtC. Among these three toxin subunits, CdtB is the toxic moiety of CDT with DNase I activity, resulting in DNA double-strand breaks (DSB and, consequently, cell cycle arrest at the G2/M stage and apoptosis. Radiation therapy is an effective modality for the treatment of localized prostate cancer (PCa. However, patients often develop radioresistance. Owing to its particular biochemical properties, we previously employed CdtB as a therapeutic agent for sensitizing radioresistant PCa cells to ionizing radiation (IR. In this study, we further demonstrated that CDT suppresses the IR-induced autophagy pathway in PCa cells by attenuating c-Myc expression and therefore sensitizes PCa cells to radiation. We further showed that CDT prevents the formation of autophagosomes via decreased high-mobility group box 1 (HMGB1 expression and the inhibition of acidic vesicular organelle (AVO formation, which are associated with enhanced radiosensitivity in PCa cells. The results of this study reveal the detailed mechanism of CDT for the treatment of radioresistant PCa.

  5. Diagnostic trends in Clostridium difficile detection in Finnish microbiology laboratories.

    Science.gov (United States)

    Könönen, Eija; Rasinperä, Marja; Virolainen, Anni; Mentula, Silja; Lyytikäinen, Outi

    2009-12-01

    Due to increased interest directed to Clostridium difficile-associated infections, a questionnaire survey of laboratory diagnostics of toxin-producing C. difficile was conducted in Finland in June 2006. Different aspects pertaining to C. difficile diagnosis, such as requests and criteria used for testing, methods used for its detection, yearly changes in diagnostics since 1996, and the total number of investigations positive for C. difficile in 2005, were asked in the questionnaire, which was sent to 32 clinical microbiology laboratories, including all hospital-affiliated and the relevant private clinical microbiology laboratories in Finland. The situation was updated by phone and email correspondence in September 2008. In June 2006, 28 (88%) laboratories responded to the questionnaire survey; 24 of them reported routinely testing requested stool specimens for C. difficile. Main laboratory methods included toxin detection (21/24; 88%) and/or anaerobic culture (19/24; 79%). In June 2006, 18 (86%) of the 21 laboratories detecting toxins directly from feces, from the isolate, or both used methods for both toxin A (TcdA) and B (TcdB), whereas only one laboratory did so in 1996. By September 2008, all of the 23 laboratories performing diagnostics for C. difficile used methods for both TcdA and TcdB. In 2006, the number of specimens processed per 100,000 population varied remarkably between different hospital districts. In conclusion, culturing C. difficile is common and there has been a favorable shift in toxin detection practice in Finnish clinical microbiology laboratories. However, the variability in diagnostic activity reported in 2006 creates a challenge for national monitoring of the epidemiology of C. difficile and related diseases.

  6. Pleiotropic roles of Clostridium difficile sin locus

    Science.gov (United States)

    Ou, Junjun; Dupuy, Bruno

    2018-01-01

    Clostridium difficile is the primary cause of nosocomial diarrhea and pseudomembranous colitis. It produces dormant spores, which serve as an infectious vehicle responsible for transmission of the disease and persistence of the organism in the environment. In Bacillus subtilis, the sin locus coding SinR (113 aa) and SinI (57 aa) is responsible for sporulation inhibition. In B. subtilis, SinR mainly acts as a repressor of its target genes to control sporulation, biofilm formation, and autolysis. SinI is an inhibitor of SinR, so their interaction determines whether SinR can inhibit its target gene expression. The C. difficile genome carries two sinR homologs in the operon that we named sinR and sinR’, coding for SinR (112 aa) and SinR’ (105 aa), respectively. In this study, we constructed and characterized sin locus mutants in two different C. difficile strains R20291 and JIR8094, to decipher the locus’s role in C. difficile physiology. Transcriptome analysis of the sinRR’ mutants revealed their pleiotropic roles in controlling several pathways including sporulation, toxin production, and motility in C. difficile. Through various genetic and biochemical experiments, we have shown that SinR can regulate transcription of key regulators in these pathways, which includes sigD, spo0A, and codY. We have found that SinR’ acts as an antagonist to SinR by blocking its repressor activity. Using a hamster model, we have also demonstrated that the sin locus is needed for successful C. difficile infection. This study reveals the sin locus as a central link that connects the gene regulatory networks of sporulation, toxin production, and motility; three key pathways that are important for C. difficile pathogenesis. PMID:29529083

  7. Clostridium difficile infection in solid organ transplant recipients.

    Science.gov (United States)

    Nanayakkara, Deepa; Nanda, Neha

    2017-08-01

    Clostridium difficile infection (CDI) is a major healthcare-associated infection that causes significant morbidity and an economic impact in the United States. In this review, we provide an overview of Clostridium difficile infection in solid organ transplant recipients with an emphasis on recent literature. C. difficile in solid organ transplant population has unique risk factors. Fecal microbiota transplantation has shown favorable results in treatment of recurrent C. difficile in this population. Preliminary data from animal studies suggests excellent efficacy with immunization against C. difficile toxins. Over the last decade, number of individuals receiving solid organ transplants has increased exponentially making peri-transplant complications a common occurrence.C. difficile is a frequent cause of morbidity in solid organ transplant recipients. Early and accurate diagnosis of C. difficile requires a stepwise approach. Differentiating between asymptomatic carriage and infection is a diagnostic challenge. Microbial diversity is inversely proportional to risk of C. difficile infection. Antimicrobial stewardship programs help to retain microbial diversity in individuals susceptible to CDI. Recurrent or relapsing C. difficile infection require fecal microbiota transplantation for definitive cure.

  8. Diagnosis of Clostridium difficile Infection: an Ongoing Conundrum for Clinicians and for Clinical Laboratories

    Science.gov (United States)

    Carroll, Karen C.

    2013-01-01

    SUMMARY Clostridium difficile is a formidable nosocomial and community-acquired pathogen, causing clinical presentations ranging from asymptomatic colonization to self-limiting diarrhea to toxic megacolon and fulminant colitis. Since the early 2000s, the incidence of C. difficile disease has increased dramatically, and this is thought to be due to the emergence of new strain types. For many years, the mainstay of C. difficile disease diagnosis was enzyme immunoassays for detection of the C. difficile toxin(s), although it is now generally accepted that these assays lack sensitivity. A number of molecular assays are commercially available for the detection of C. difficile. This review covers the history and biology of C. difficile and provides an in-depth discussion of the laboratory methods used for the diagnosis of C. difficile infection (CDI). In addition, strain typing methods for C. difficile and the evolving epidemiology of colonization and infection with this organism are discussed. Finally, considerations for diagnosing C. difficile disease in special patient populations, such as children, oncology patients, transplant patients, and patients with inflammatory bowel disease, are described. As detection of C. difficile in clinical specimens does not always equate with disease, the diagnosis of C. difficile infection continues to be a challenge for both laboratories and clinicians. PMID:23824374

  9. An Inactive Geminin Mutant That Binds Cdt1

    Directory of Open Access Journals (Sweden)

    Marissa Suchyta

    2015-05-01

    Full Text Available The initiation of DNA replication is tightly regulated in order to ensure that the genome duplicates only once per cell cycle. In vertebrate cells, the unstable regulatory protein Geminin prevents a second round of DNA replication by inhibiting the essential replication factor Cdt1. Cdt1 recruits mini-chromosome maintenance complex (MCM2-7, the replication helicase, into the pre-replication complex (pre-RC at origins of DNA replication. The mechanism by which Geminin inhibits MCM2-7 loading by Cdt1 is incompletely understood. The conventional model is that Geminin sterically hinders a direct physical interaction between Cdt1 and MCM2-7. Here, we describe an inactive missense mutant of Geminin, GemininAWA, which binds to Cdt1 with normal affinity yet is completely inactive as a replication inhibitor even when added in vast excess. In fact, GemininAWA can compete with GemininWT for binding to Cdt1 and prevent it from inhibiting DNA replication. GemininAWA does not inhibit the loading of MCM2-7 onto DNA in vivo, and in the presence of GemininAWA, nuclear DNA is massively over-replicated within a single S phase. We conclude that Geminin does not inhibit MCM loading by simple steric interference with a Cdt1-MCM2-7 interaction but instead works by a non-steric mechanism, possibly by inhibiting the histone acetyltransferase HBO1.

  10. Cytolethal distending toxin in isolates of Aggregatibacter actinomycetemcomitans from Ghanaian adolescents and association with serotype and disease progression.

    Science.gov (United States)

    Höglund Åberg, Carola; Antonoglou, Georgios; Haubek, Dorte; Kwamin, Francis; Claesson, Rolf; Johansson, Anders

    2013-01-01

    The cytolethal distending toxin (Cdt) is a highly conserved exotoxin that are produced by a number of Gram negative bacteria, including Aggregatibacter actinomycetemcomitans, and affects mammalian cells by inhibiting cell division and causing apoptosis. A complete cdt-operon is present in the majority of A. actinomycetemcomitans, but the proportion of isolates that lack cdt-encoding genes (A, B and C) varies according to the population studied. The objectives of this study were to examine serotype, Cdt-genotype, and Cdt-activity in isolates of A. actinomycetemcomitans collected from an adolescent West African population and to examine the association between the carrier status of A. actinomycetemcomitans and the progression of attachment loss (AL). A total of 249 A. actinomycetemcomitans isolates from 200 Ghanaian adolescents were examined for serotype and cdt-genotype by PCR. The activity of the Cdt-toxin was examined by DNA-staining of exposed cultured cells and documented with flow cytometry. The periodontal status of the participants was examined at baseline and at a two-year follow-up. Presence of all three cdt-encoding genes was detected in 79% of the examined A. actinomycetemcomitans isolates. All these isolates showed a substantial Cdt-activity. The two different cdt-genotypes (with and without presence of all three cdt-encoding genes) showed a serotype-dependent distribution pattern. Presence of A. actinomycetemcomitans was significantly associated with progression of AL (OR = 5.126; 95% CI = [2.994-8.779], padolescents showed a distribution of serotype and cdt-genotype in line with results based on other previously studied populations. Presence of A. actinomycetemcomitans was significantly associated with disease progression, in particular the b serotype, whereas the association with disease progression was not particularly related to cdt-genotype, and Cdt-activity.

  11. Suppression by Saccharomyces boulardii of toxigenic Clostridium difficile overgrowth after vancomycin treatment in hamsters.

    Science.gov (United States)

    Elmer, G W; McFarland, L V

    1987-01-01

    Saccharomyces boulardii prevented the development of high counts of Clostridium difficile, high titers of toxin B, and positive latex agglutination tests after cessation of vancomycin treatment for hamsters. The protocol used was designed to stimulate relapse of human C. difficile-associated colitis. S. boulardii was protective in this model. PMID:3566236

  12. Characteristics of the new phase in CDT

    Energy Technology Data Exchange (ETDEWEB)

    Ambjoern, J. [Copenhagen University, The Niels Bohr Institute, Copenhagen Oe (Denmark); Radboud University, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Nijmegen (Netherlands); Gizbert-Studnicki, J.; Jurkiewicz, J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Goerlich, A. [Copenhagen University, The Niels Bohr Institute, Copenhagen Oe (Denmark); Jagiellonian University, Institute of Physics, Krakow (Poland); Klitgaard, N.; Loll, R. [Radboud University, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Nijmegen (Netherlands)

    2017-03-15

    The approach of Causal Dynamical Triangulations (CDT), a candidate theory of nonperturbative quantum gravity in 4D, turns out to have a rich phase structure. We investigate the recently discovered bifurcation phase C{sub b} and relate some of its characteristics to the presence of singular vertices of very high order. The transition lines separating this phase from the ''time-collapsed'' B-phase and the de Sitter phase C{sub dS} are of great interest when searching for physical scaling limits. The work presented here sheds light on the mechanisms behind these transitions. First, we study how the B-C{sub b} transition signal depends on the volume fixing implemented in the simulations, and find results compatible with the previously determined second-order character of the transition. The transition persists in a transfer matrix formulation, where the system's time extension is taken to be minimal. Second, we relate the new C{sub b}-C{sub dS} transition to the appearance of singular vertices, which leads to a direct physical interpretation in terms of a breaking of the homogeneity and isotropy observed in the de Sitter phase when crossing from C{sub dS} to the bifurcation phase C{sub b}. (orig.)

  13. Cytolethal Distending Toxin From Campylobacter jejuni Requires the Cytoskeleton for Toxic Activity.

    Science.gov (United States)

    Méndez-Olvera, Estela T; Bustos-Martínez, Jaime A; López-Vidal, Yolanda; Verdugo-Rodríguez, Antonio; Martínez-Gómez, Daniel

    2016-10-01

    Campylobacter jejuni is one of the major causes of infectious diarrhea worldwide. The distending cytolethal toxin (CDT) of Campylobacter spp. interferes with normal cell cycle progression. This toxic effect is considered a result of DNase activity that produces chromosomal DNA damage. To perform this event, the toxin must be endocytosed and translocated to the nucleus. The aim of this study was to evaluate the role of the cytoskeleton in the translocation of CDT to the nucleus. Campylobacter jejuni ATCC 33291 and seven isolates donated from Instituto de Biotecnologia were used in this study. The presence of CDT genes in C. jejuni strains was determined by PCR. To evaluate the effect of CDT, HeLa cells were treated with bacterial lysate, and the damage and morphological changes were analyzed by microscopy, immunofluorescence staining, and flow cytometry. To evaluate the role of the cytoskeleton, HeLa cells were treated with either latrunculin A or by nocodazole and analyzed by microscopy, flow cytometry, and immunoquantification (ELISA). The results obtained showed that the eight strains of C. jejuni , including the reference strain, had the ability to produce the toxin. Usage of latrunculin A and nocodazole, two cytoskeletal inhibitors, blocked the toxic effect in cells treated with the toxin. This phenomenon was evident in flow cytometry analysis and immunoquantification of Cdc2-phosphorylated. This work showed that the cytotoxic activity of the C. jejuni CDT is dependent on its endocytosis. The alteration in the microtubules and actin filaments caused a blockage transit of the toxin, preventing it from reaching the nucleus of the cell, as well as preventing DNA fragmentation and alteration of the cell cycle. The CDT toxin appears to be an important element for the pathogenesis of campylobacteriosis, since all clinical isolates showed the presence of cdtA , cdtB and cdtC genes.

  14. Cytolethal Distending Toxin From Campylobacter jejuni Requires the Cytoskeleton for Toxic Activity

    Science.gov (United States)

    Méndez-Olvera, Estela T.; Bustos-Martínez, Jaime A.; López-Vidal, Yolanda; Verdugo-Rodríguez, Antonio; Martínez-Gómez, Daniel

    2016-01-01

    Background Campylobacter jejuni is one of the major causes of infectious diarrhea worldwide. The distending cytolethal toxin (CDT) of Campylobacter spp. interferes with normal cell cycle progression. This toxic effect is considered a result of DNase activity that produces chromosomal DNA damage. To perform this event, the toxin must be endocytosed and translocated to the nucleus. Objectives The aim of this study was to evaluate the role of the cytoskeleton in the translocation of CDT to the nucleus. Methods Campylobacter jejuni ATCC 33291 and seven isolates donated from Instituto de Biotecnologia were used in this study. The presence of CDT genes in C. jejuni strains was determined by PCR. To evaluate the effect of CDT, HeLa cells were treated with bacterial lysate, and the damage and morphological changes were analyzed by microscopy, immunofluorescence staining, and flow cytometry. To evaluate the role of the cytoskeleton, HeLa cells were treated with either latrunculin A or by nocodazole and analyzed by microscopy, flow cytometry, and immunoquantification (ELISA). Results The results obtained showed that the eight strains of C. jejuni, including the reference strain, had the ability to produce the toxin. Usage of latrunculin A and nocodazole, two cytoskeletal inhibitors, blocked the toxic effect in cells treated with the toxin. This phenomenon was evident in flow cytometry analysis and immunoquantification of Cdc2-phosphorylated. Conclusions This work showed that the cytotoxic activity of the C. jejuni CDT is dependent on its endocytosis. The alteration in the microtubules and actin filaments caused a blockage transit of the toxin, preventing it from reaching the nucleus of the cell, as well as preventing DNA fragmentation and alteration of the cell cycle. The CDT toxin appears to be an important element for the pathogenesis of campylobacteriosis, since all clinical isolates showed the presence of cdtA, cdtB and cdtC genes. PMID:27942359

  15. [New methodological advances: algorithm proposal for management of Clostridium difficile infection].

    Science.gov (United States)

    González-Abad, María José; Alonso-Sanz, Mercedes

    2015-06-01

    Clostridium difficile infection (CDI) is considered the most common cause of health care-associated diarrhea and also is an etiologic agent of community diarrhea. The aim of this study was to assess the potential benefit of a test that detects glutamate dehydrogenase (GDH) antigen and C. difficile toxin A/B, simultaneously, followed by detection of C. difficile toxin B (tcdB) gene by PCR as confirmatory assay on discrepant samples, and to propose an algorithm more efficient. From June 2012 to January 2013 at Hospital Infantil Universitario Niño Jesús, Madrid, the stool samples were studied for the simultaneous detection of GDH and toxin A/B, and also for detection of toxin A/B alone. When results between GDH and toxin A/B were discordant, a single sample for patient was selected for detection of C. difficile toxin B (tcdB) gene. A total of 116 samples (52 patients) were tested. Four were positive and 75 negative for toxigenic C. difficile (Toxin A/B, alone or combined with GDH). C. difficile was detected in the remaining 37 samples but not toxin A/B, regardless of the method used, except one. Twenty of the 37 specimens were further tested for C. difficile toxin B (tcdB) gene and 7 were positive. The simultaneous detection of GDH and toxin A/B combined with PCR recovered undiagnosed cases of CDI. In accordance with our data, we propose a two-step algorithm: detection of GDH and PCR (in samples GDH positive). This algorithm could provide a superior cost-benefit ratio in our population.

  16. Clostridium difficile carriage in adult cystic fibrosis (CF); implications for patients with CF and the potential for transmission of nosocomial infection.

    Science.gov (United States)

    Burke, D G; Harrison, M J; Fleming, C; McCarthy, M; Shortt, C; Sulaiman, I; Murphy, D M; Eustace, J A; Shanahan, F; Hill, C; Stanton, C; Rea, M C; Ross, R P; Plant, B J

    2017-03-01

    Clostridium difficile is an anaerobic Gram-positive, spore-forming, toxin-producing bacillus transmitted among humans through the faecal-oral route. Despite increasing carriage rates and the presence of C. difficile toxin in stool, patients with CF rarely appear to develop typical manifestations of C. difficile infection (CDI). In this study, we examined the carriage, toxin production, ribotype distribution and antibiotic susceptibility of C. difficile in a cohort of 60 adult patients with CF who were pre-lung transplant. C. difficile was detected in 50% (30/60) of patients with CF by culturing for the bacteria. C. difficile toxin was detected in 63% (19/30) of C. difficile-positive stool samples. All toxin-positive stool samples contained toxigenic C. difficile strains harbouring toxin genes, tcdA and tcdB. Despite the presence of C. difficile and its toxin in patient stool, no acute gastrointestinal symptoms were reported. Ribotyping of C. difficile strains revealed 16 distinct ribotypes (RT), 11 of which are known to be disease-causing including the hyper-virulent RT078. Additionally, strains RT002, RT014, and RT015, which are common in non-CF nosocomial infection were described. All strains were susceptible to vancomycin, metronidazole, fusidic acid and rifampicin. No correlation was observed between carriage of C. difficile or any characteristics of isolated strains and any recorded clinical parameters or treatment received. We demonstrate a high prevalence of hypervirulent, toxigenic strains of C. difficile in asymptomatic patients with CF. This highlights the potential role of asymptomatic patients with CF in nosocomial transmission of C. difficile. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  17. Emerging monoclonal antibodies against Clostridium difficile infection.

    Science.gov (United States)

    Péchiné, Séverine; Janoir, Claire; Collignon, Anne

    2017-04-01

    Clostridium difficile infections are characterized by a high recurrence rate despite antibiotic treatments and there is an urgent need to develop new treatments such as fecal transplantation and immonotherapy. Besides active immunotherapy with vaccines, passive immunotherapy has shown promise, especially with monoclonal antibodies. Areas covered: Herein, the authors review the different assays performed with monoclonal antibodies against C. difficile toxins and surface proteins to treat or prevent primary or recurrent episodes of C. difficile infection in animal models and in clinical trials as well. Notably, the authors lay emphasis on the phase III clinical trial (MODIFY II), which allowed bezlotoxumab to be approved by the Food and Drug Administration and the European Medicines Agency. They also review new strategies for producing single domain antibodies and nanobodies against C. difficile and new approaches to deliver them in the digestive tract. Expert opinion: Only two human Mabs against TcdA and TcdB have been tested alone or in combination in clinical trials. However, many animal model studies have provided rationale for the use of Mabs and nanobodies in C. difficile infection and pave the way for further clinical investigation.

  18. Cdt1 stabilizes an open MCM ring for helicase loading.

    Science.gov (United States)

    Frigola, Jordi; He, Jun; Kinkelin, Kerstin; Pye, Valerie E; Renault, Ludovic; Douglas, Max E; Remus, Dirk; Cherepanov, Peter; Costa, Alessandro; Diffley, John F X

    2017-06-23

    ORC, Cdc6 and Cdt1 act together to load hexameric MCM, the motor of the eukaryotic replicative helicase, into double hexamers at replication origins. Here we show that Cdt1 interacts with MCM subunits Mcm2, 4 and 6, which both destabilizes the Mcm2-5 interface and inhibits MCM ATPase activity. Using X-ray crystallography, we show that Cdt1 contains two winged-helix domains in the C-terminal half of the protein and a catalytically inactive dioxygenase-related N-terminal domain, which is important for MCM loading, but not for subsequent replication. We used these structures together with single-particle electron microscopy to generate three-dimensional models of MCM complexes. These show that Cdt1 stabilizes MCM in a left-handed spiral open at the Mcm2-5 gate. We propose that Cdt1 acts as a brace, holding MCM open for DNA entry and bound to ATP until ORC-Cdc6 triggers ATP hydrolysis by MCM, promoting both Cdt1 ejection and MCM ring closure.

  19. Specificity of antibodies directed against the cytolethal distending toxin of Haemophilus ducreyi in patients with chancroid.

    Science.gov (United States)

    Mbwana, Judica; Ahmed, Hinda J; Ahlman, Karin; Sundaeus, Vivian; Dahlén, Gunnar; Lyamuya, Eligius; Lagergård, Teresa

    2003-09-01

    Antibodies specific for the cytolethal-distending toxin of Haemophilus ducreyi (HdCDT) complex and for the CdtA, CdtB, and CdtC components were measured by ELISA in the sera of 50 patients with culture and/or PCR proven chancroid, 42 patients with periodontitis, 50 blood donors from Tanzania, 50 blood donors from Sweden. In addition, the biological activity e.g. neutralization capacity of the sera were tested. Our results demonstrate that majority of chancroid patients and healthy individuals had detectable levels of serum antibodies to HdCDT complex and to separate toxin components. However, high levels (> or =100 units) of antibodies to HdCDT complex were significantly more prevalent in the sera of patients with both chancroid and periodontitis than in the sera of the corresponding controls (P=0.001 and P=0.04, respectively). In the sera of the 50 patients with chancroid, antibodies to CdtA, CdtB, and CdtC were detected in 50, 35, and 34 individuals, respectively. Antibodies to CdtC, being less frequently detected than the antibodies to other components, show a good correlation with the neutralizing capacity of sera. High levels of neutralizing antibodies (> or =160) were detected in only 22 and 2% of the patients with chancroid and periodontitis, respectively. The data suggest that the low levels of anti-HdCDT antibodies, which include neutralizing antibodies, may contribute to limited protection in chancroid and since anti-HdCDT antibodies, may be detected in healthy individuals and in patients with certain disease conditions (e.g. periodontitis), they may not be specific markers for chancroid infection.

  20. Evaluation of Correlation between Pretest Probability for Clostridium difficile Infection and Clostridium difficile Enzyme Immunoassay Results.

    Science.gov (United States)

    Kwon, Jennie H; Reske, Kimberly A; Hink, Tiffany; Burnham, C A; Dubberke, Erik R

    2017-02-01

    The objective of this study was to evaluate the clinical characteristics and outcomes of hospitalized patients tested for Clostridium difficile and determine the correlation between pretest probability for C. difficile infection (CDI) and assay results. Patients with testing ordered for C. difficile were enrolled and assigned a high, medium, or low pretest probability of CDI based on clinical evaluation, laboratory, and imaging results. Stool was tested for C. difficile by toxin enzyme immunoassay (EIA) and toxigenic culture (TC). Chi-square analyses and the log rank test were utilized. Among the 111 patients enrolled, stool samples from nine were TC positive and four were EIA positive. Sixty-one (55%) patients had clinically significant diarrhea, 19 (17%) patients did not, and clinically significant diarrhea could not be determined for 31 (28%) patients. Seventy-two (65%) patients were assessed as having a low pretest probability of having CDI, 34 (31%) as having a medium probability, and 5 (5%) as having a high probability. None of the patients with low pretest probabilities had a positive EIA, but four were TC positive. None of the seven patients with a positive TC but a negative index EIA developed CDI within 30 days after the index test or died within 90 days after the index toxin EIA date. Pretest probability for CDI should be considered prior to ordering C. difficile testing and must be taken into account when interpreting test results. CDI is a clinical diagnosis supported by laboratory data, and the detection of toxigenic C. difficile in stool does not necessarily confirm the diagnosis of CDI. Copyright © 2017 American Society for Microbiology.

  1. Evaluation of an interdisciplinary re-isolation policy for patients with previous Clostridium difficile diarrhea.

    Science.gov (United States)

    Boone, N; Eagan, J A; Gillern, P; Armstrong, D; Sepkowitz, K A

    1998-12-01

    Diarrhea caused by Clostridium difficile is increasingly recognized as a nosocomial problem. The effectiveness and cost of a new program to decrease nosocomial spread by identifying patients scheduled for readmission who were previously positive for toxin was evaluated. The Memorial Sloan-Kettering Cancer Center is a 410-bed comprehensive cancer center in New York City. Many patients are readmitted during their course of cancer therapy. In 1995 as a result of concern about the nosocomial spread of C difficile, we implemented a policy that all patients who were positive for C difficile toxin in the previous 6 months with no subsequent toxin-negative stool as an outpatient would be placed into contact isolation on readmission pending evaluation of stool specimens. Patients who were previously positive for C difficile toxin were identified to infection control and admitting office databases via computer. Admitting personnel contacted infection control with all readmissions to determine whether a private room was required. Between July 1, 1995, and June 30, 1996, 47 patients who were previously positive for C difficile toxin were readmitted. Before their first scheduled readmission, the specimens for 15 (32%) of these patients were negative for C difficile toxin. They were subsequently cleared as outpatients and were readmitted without isolation. Workup of the remaining 32 patients revealed that the specimens for 7 patients were positive for C difficile toxin and 86 isolation days were used. An additional 25 patients used 107 isolation days and were either cleared after a negative specimen was obtained in-house or discharged without having an appropriate specimen sent. Four patients (9%) had reoccurring C difficile after having toxin-negative stools. We estimate (because outpatient specimens were not collected) the cost incurred at $48,500 annually, including the incremental cost of hospital isolation and equipment. Our policy to control the spread of nosocomial C

  2. Effect of tcdR Mutation on Sporulation in the Epidemic Clostridium difficile Strain R20291.

    Science.gov (United States)

    Girinathan, Brintha P; Monot, Marc; Boyle, Daniel; McAllister, Kathleen N; Sorg, Joseph A; Dupuy, Bruno; Govind, Revathi

    2017-01-01

    Clostridium difficile is an important nosocomial pathogen and the leading cause of hospital-acquired diarrhea. Antibiotic use is the primary risk factor for the development of C. difficile -associated disease because it disrupts normally protective gut flora and enables C. difficile to colonize the colon. C. difficile damages host tissue by secreting toxins and disseminates by forming spores. The toxin-encoding genes, tcdA and tcdB , are part of a pathogenicity locus, which also includes the tcdR gene that codes for TcdR, an alternate sigma factor that initiates transcription of tcdA and tcdB genes. We created a tcdR mutant in epidemic-type C. difficile strain R20291 in an attempt to identify the global role of tcdR . A site-directed mutation in tcdR affected both toxin production and sporulation in C. difficile R20291. Spores of the tcdR mutant were more heat sensitive than the wild type (WT). Nearly 3-fold more taurocholate was needed to germinate spores from the tcdR mutant than to germinate the spores prepared from the WT strain. Transmission electron microscopic analysis of the spores also revealed a weakly assembled exosporium on the tcdR mutant spores. Accordingly, comparative transcriptome analysis showed many differentially expressed sporulation genes in the tcdR mutant compared to the WT strain. These data suggest that regulatory networks of toxin production and sporulation in C. difficile strain R20291 a re linked with each other. IMPORTANCE C. difficile infects thousands of hospitalized patients every year, causing significant morbidity and mortality. C. difficile spores play a pivotal role in the transmission of the pathogen in the hospital environment. During infection, the spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. Thus, sporulation and toxin production are two important traits of C. difficile . In this study, we showed that a mutation in tcdR , the toxin gene regulator, affects both toxin

  3. Accessory Gene Regulator-1 Locus Is Essential for Virulence and Pathogenesis of Clostridium difficile

    Directory of Open Access Journals (Sweden)

    Charles Darkoh

    2016-08-01

    Full Text Available Clostridium difficile infection (CDI is responsible for most of the definable cases of antibiotic- and hospital-associated diarrhea worldwide and is a frequent cause of morbidity and mortality in older patients. C. difficile, a multidrug-resistant anaerobic pathogen, causes disease by producing toxins A and B, which are controlled by an accessory gene regulator (Agr quorum signaling system. Some C. difficile strains encode two Agr loci in their genomes, designated agr1 and agr2. The agr1 locus is present in all of the C. difficile strains sequenced to date, whereas the agr2 locus is present in a few strains. The functional roles of agr1 and agr2 in C. difficile toxin regulation and pathogenesis were unknown until now. Using allelic exchange, we deleted components of both agr loci and examined the mutants for toxin production and virulence. The results showed that the agr1 mutant cannot produce toxins A and B; toxin production can be restored by complementation with wild-type agr1. Furthermore, the agr1 mutant is able to colonize but unable to cause disease in a murine CDI model. These findings have profound implications for CDI treatment because we have uncovered a promising therapeutic target for the development of nonantibiotic drugs to treat this life-threatening emerging pathogen by targeting the toxins directly responsible for disease.

  4. The cytolethal distending toxin of Haemophilus ducreyi aggravates dermal lesions in a rabbit model of chancroid.

    Science.gov (United States)

    Wising, Catharina; Mölne, Lena; Jonsson, Ing-Marie; Ahlman, Karin; Lagergård, Teresa

    2005-05-01

    Haemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, produces a cytolethal distending toxin (HdCDT) that inhibits cultured cell proliferation, leading to cell death. A rabbit model of dermal infection was used to investigate the roles of H. ducreyi bacteria and HdCDT in the development, clinical appearance, and persistence of infection. A non-toxin producing H. ducreyi strain, and for comparison purposes a non-capsulated Haemophilus influenzae strain, were inoculated intradermally, with and without co-administration of purified HdCDT. Co-administration of HdCDT resulted in significant aggravation of H. ducreyi-induced inflammatory lesions, and development of ulcers in rabbit skin. Less pronounced inflammatory lesions and lack of epithelial eruption were observed after inoculation with H. influenzae. Histopathological sections of the H. ducreyi-induced lesions, in both the presence and absence of HdCDT, showed dense infiltrates of the same type inflammatory cells, with the exception of a prominent endothelial cell proliferation noted in sections from lesions caused by H. ducreyi and toxin. Signs of chronic inflammation with involvement of T cells, macrophages, eosinophils, and granuloma formation were observed after H. ducreyi inoculation both with and without toxin. In conclusion, H. ducreyi causes a pronounced, chronic inflammation with involvement of T cells and macrophages, and in combination with HdCDT production of ulcers in the rabbit model. These pathogenic mechanisms may promote the development and persistence of chancroid ulcers.

  5. Stop C. difficile Infections

    Centers for Disease Control (CDC) Podcasts

    This podcast is based on the March 2012 CDC Vital Signs report. C. difficile is a germ that causes diarrhea linked to 14,000 deaths in the US each year. This podcast helps health care professionals learn how to prevent C. difficile infections.

  6. Stool Test: C. Difficile Toxin (For Parents)

    Science.gov (United States)

    ... sealable container before taking it to the lab. Plastic wrap also can be used to line the diaper of an infant or toddler who isn't yet using the toilet. The wrap should be placed so that urine ... be collected into a clean, dry plastic jar with a screw-cap lid. For best ...

  7. Clostridium difficile in Crete, Greece: epidemiology, microbiology and clinical disease.

    Science.gov (United States)

    Samonis, G; Vardakas, K Z; Tansarli, G S; Dimopoulou, D; Papadimitriou, G; Kofteridis, D P; Maraki, S; Karanika, M; Falagas, M E

    2016-01-01

    We studied the epidemiology and microbiology of Clostridium difficile and the characteristics of patients with C. difficile infection (CDI) in Crete in three groups of hospitalized patients with diarrhoea: group 1 [positive culture and positive toxin by enzyme immunoassay (EIA)]; group 2 (positive culture, negative toxin); group 3 (negative culture, negative toxin). Patients in group 1 were designated as those with definitive CDI (20 patients for whom data was available) and matched with cases in group 2 (40 patients) and group 3 (40 patients). C. difficile grew from 6% (263/4379) of stool specimens; 14·4% of these had positive EIA, of which 3% were resistant to metronidazole. Three isolates had decreased vancomycin susceptibility. Patients in groups 1 and 2 received more antibiotics (P = 0·03) and had more infectious episodes (P = 0·03) than patients in group 3 prior to diarrhoea. Antibiotic administration for C. difficile did not differ between groups 1 and 2. Mortality was similar in all three groups (10%, 12·5% and 5%, P = 0·49). CDI frequency was low in the University Hospital of Crete and isolates were susceptible to metronidazole and vancomycin.

  8. Clostridium difficile infection in the Lao People's Democratic Republic: first isolation and review of the literature.

    Science.gov (United States)

    Cheong, Elaine; Roberts, Tamalee; Rattanavong, Sayaphet; Riley, Thomas V; Newton, Paul N; Dance, David A B

    2017-09-21

    Current knowledge of the epidemiology of Clostridium difficile infection in Asia, and in particular the Greater Mekong Subregion, is very limited. Only a few studies from Thailand and Vietnam have been reported from the region with variable testing methods and results, and no studies from Lao People's Democratic Republic (PDR). Therefore we investigated the presence of C. difficile in a single centre in the Lao PDR and determined the ribotypes present. Seventy unformed stool samples from hospital inpatients at Mahosot Hospital, Vientiane, were tested for the presence of C. difficile using selective differential agar and confirmed by latex agglutination. C. difficile isolates were further characterised by ribotyping and toxin gene detection. C. difficile was isolated from five of the 70 patients, and five different ribotypes were identified (014, 017, 020, QX 107 and QX 574). This is the first isolation of C. difficile from human stool samples in the Lao PDR. These results will add to the limited amount of data on C. difficile in the region. In addition, we hope this information will alert clinicians to the presence of C. difficile in the country and will help inform future investigations into the epidemiology and diagnosis of C. difficile in Lao PDR.

  9. A Small Molecule-Screening Pipeline to Evaluate the Therapeutic Potential of 2-Aminoimidazole Molecules Against Clostridium difficile

    Directory of Open Access Journals (Sweden)

    Rajani Thanissery

    2018-06-01

    Full Text Available Antibiotics are considered to be the first line of treatment for mild to moderately severe Clostridium difficile infection (CDI in humans. However, antibiotics are also risk factors for CDI as they decrease colonization resistance against C. difficile by altering the gut microbiota and metabolome. Finding compounds that selectively inhibit different stages of the C. difficile life cycle, while sparing the indigenous gut microbiota is important for the development of alternatives to standard antibiotic treatment. 2-aminoimidazole (2-AI molecules are known to disrupt bacterial protection mechanisms in antibiotic resistant bacteria such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus, but are yet to be evaluated against C. difficile. A comprehensive small molecule-screening pipeline was developed to investigate how novel small molecules affect different stages of the C. difficile life cycle (growth, toxin, and sporulation in vitro, and a library of commensal bacteria that are associated with colonization resistance against C. difficile. The initial screening tested the efficacy of eleven 2-AI molecules (compound 1 through 11 against C. difficile R20291 compared to a vancomycin (2 μg/ml control. Molecules were selected for their ability to inhibit C. difficile growth, toxin activity, and sporulation. Further testing included growth inhibition of other C. difficile strains (CD196, M68, CF5, 630, BI9, M120 belonging to distinct PCR ribotypes, and a commensal panel (Bacteroides fragilis, B. thetaiotaomicron, C. scindens, C. hylemonae, Lactobacillus acidophilus, L. gasseri, Escherichia coli, B. longum subsp. infantis. Three molecules compound 1 and 2, and 3 were microbicidal, whereas compounds 4, 7, 9, and 11 inhibited toxin activity without affecting the growth of C. difficile strains and the commensal microbiota. The antimicrobial and anti-toxin effects of 2-AI molecules need to be further characterized for mode of

  10. Geminin deploys multiple mechanisms to regulate Cdt1 before cell division thus ensuring the proper execution of DNA replication

    DEFF Research Database (Denmark)

    Ballabeni, Andrea; Zamponi, Raffaella; Moore, Jodene K

    2013-01-01

    the accumulation of Cdt1 in mitosis, because decreasing the Geminin levels prevents Cdt1 accumulation and impairs DNA replication. Geminin is known to inhibit Cdt1 function; its depletion during G2 leads to DNA rereplication and checkpoint activation. Here we show that, despite rapid Cdt1 protein turnover in G2...

  11. Stop C. difficile Infections

    Centers for Disease Control (CDC) Podcasts

    2012-03-06

    This podcast is based on the March 2012 CDC Vital Signs report. C. difficile is a germ that causes diarrhea linked to 14,000 deaths in the US each year. This podcast helps health care professionals learn how to prevent C. difficile infections.  Created: 3/6/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/6/2012.

  12. The incidence and clinical symptomatology of Clostridium difficile infections in a community setting in a cohort of Danish patients attending general practice

    DEFF Research Database (Denmark)

    Søes, Lillian Marie; Holt, H M; Böttiger, B

    2014-01-01

    Clostridium difficile infection (CDI) is gradually being recognised as a cause of morbidity in the community. We investigated the incidence and clinical characteristics of CDI in a community setting and characterised the C. difficile strains by toxin gene profiling and polymerase chain reaction (...

  13. Rifaximin therapy for metronidazole-unresponsive Clostridium difficile infection: a prospective pilot trial.

    Science.gov (United States)

    Patrick Basu, P; Dinani, Amreen; Rayapudi, Krishna; Pacana, Tommy; Shah, Niraj James; Hampole, Hemant; Krishnaswamy, N V; Mohan, Vinod

    2010-07-01

    Clostridium difficile infection (CDI) is a recent epidemic in the United States, particularly in the hospital setting. Oral metronidazole is standard therapy for C. difficile infection, but resistance to metronidazole is becoming a clinical challenge. We evaluated the efficacy of the nonsystemic oral antibiotic rifaximin for the treatment of metronidazole-resistant C. difficile infection. Twenty-five patients with C. difficile infection were enrolled in the study. All had mild-to-moderate C. difficile infection (5-10 bowel movements a day without sepsis) unresponsive to metronidazole (i.e. stools positive for toxins A and B after oral metronidazole 500 mg three times daily [t.i.d.] for 5 days). After discontinuation of metronidazole, rifaximin 400 mg t.i.d. for 14 days was prescribed. Patients were followed for 56 days and stool was tested for C. difficile using polymerase chain reaction (PCR) to assess the effect of treatment. A negative PCR test result was interpreted as a favorable response to rifaximin. Sixteen of 22 patients (73%) were eligible for study inclusion and completed rifaximin therapy experienced eradication of infection (stool negative for C. difficile) immediately after rifaximin therapy and 56 days post-treatment. Three patients (12%) discontinued therapy because of abdominal distention. Rifaximin was generally well tolerated. In conclusion, rifaximin may be considered for treatment of mild-to-moderate C. difficile infection that is resistant to metronidazole. Larger randomized trials are needed to confirm these positive findings.

  14. High prevalence of toxigenic Clostridium difficile in public space lawns in Western Australia.

    Science.gov (United States)

    Moono, Peter; Lim, Su Chen; Riley, Thomas V

    2017-02-01

    Clostridium difficile is a well-established hospital pathogen. Recently, it has been detected increasingly in patients without hospital contact. Given this rise in community associated infections with C. difficile, we hypothesized that the environment could play an important role in transmission of spores outside the hospital. Lawn samples (311) collected in public spaces in the metropolitan area of Perth, Western Australia, from February to June 2016 were cultured for C. difficile. C. difficile was isolated from the samples by direct and enrichment culture, and characterized by standard molecular methods using toxin gene PCR and ribotyping. The overall prevalence of C. difficile was 59%, new lawn (≤4 months old) was twice as likely as old lawn (>4 months old) to test positive (OR = 2.3; 95%CI 1.16-4.57, p = 0.015) and 35 C. difficile ribotypes were identified with toxigenic ribotype 014/020 (39%) predominating. The highest viable count from lawn soil samples was 1200 CFU/g. These results show that lawns in Perth, Western Australia, harbor toxigenic C. difficile, an important finding. The source of lawn contamination is likely related to modern practice of producing "roll-out" lawn. Further work should focus on identifying specific management practices that lead to C. difficile contamination of lawn to inform prevention and control measures.

  15. Epidemiological Features of Clostridium difficile Colonizing the Intestine of Jordanian Infants

    Directory of Open Access Journals (Sweden)

    Eman N. Abu-Khader

    2017-01-01

    Full Text Available Clostridium difficile is commonly found in the intestine of infants without causing any disease. This study investigated the most important epidemiological features of C. difficile strains colonizing intestine of Jordanian infants. A total of 287 fecal samples were collected from infants admitted to the Jordan University Hospital (JUH over the period of 2015. Samples were cultured for C. difficile and their growth was identified using microbiological culture and PCR. The overall C. difficile colonization rate among hospitalized and nonhospitalized infants was 37/287 (12.9%. Neonates were less colonized than other infants (8.7% verses 19.5%. Colonization of the infants with C. difficile toxigenic strains (TcdA and TcdB was observed in 54% of the isolates, whereas those colonized with nontoxigenic strains were 46% and only one isolate was positive for binary toxin. Breast feeding of infants is a significant factor associated with decreased colonization with C. difficile. All C. difficile strains were susceptible to vancomycin and metronidazole, while high resistance rate to ciprofloxacin (78.4% and less resistance rate to erythromycin (29.7% were detected among the isolates. The results showed that 40.5% of the isolates carried mutated gyrA and gyrB genes which have cross-resistance to ciprofloxacin and moxifloxacin. This study represents useful epidemiological features about C. difficile colonizing intestine of infants living in a developing country.

  16. Clostridium difficile in retail meat and processing plants in Texas.

    Science.gov (United States)

    Harvey, Roger B; Norman, Keri N; Andrews, Kathleen; Norby, Bo; Hume, Michael E; Scanlan, Charles M; Hardin, Margaret D; Scott, Harvey M

    2011-07-01

    The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America from the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer to human beings. The objective of the present study was to determine the prevalence of C. difficile in pork from sausage manufacturing plants and retail meat in Texas. Twenty-three C. difficile isolates were detected from 243 meat samples (9.5%) from 3 sausage-manufacturing plants and 5 retail meat outlets from 2004 to 2009. Twenty-two isolates were positive for toxins A, B, and binary toxin, and were characterized as toxinotype V, PFGE type-NAP7, or "NAP7-variant." Susceptibilities to 11 antimicrobial agents in the current study were similar to those reported previously for toxinotype V isolates, although the results suggested somewhat reduced resistance than reported for other meat, animal, or human clinical toxinotype V isolates.

  17. Prevalence and molecular epidemiology of Clostridium difficile infection in Indonesia

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    D.A. Collins

    2017-07-01

    Full Text Available Clostridium difficile has not been studied in detail in Asia, particularly Southeast Asia. We thus performed a prevalence study across four hospitals in Central Java province, Indonesia. Stool samples were collected from patients with diarrhoea and tested by enzyme immunoassay for glutamate dehydrogenase (GDH and toxin A/B (C DIFF QUIK CHEK COMPLETE, TechLab. Specimens were cultured and molecular typing was performed. In total, 340 samples were tested, of which 70 (20.6% were GDH positive, with toxin detected in 19 (5.6%. Toxigenic C. difficile was isolated from 37 specimens (10.9%, while a further 36 (10.6% nontoxigenic isolates were identified. The most common strain was ribotype 017 (24.3% of 74 isolates, followed by nontoxigenic types QX 224 (9.5%, and QX 238 and QX 108 (both 8.1%. The high prevalence of C. difficile highlights a need for ongoing surveillance of C. difficile infection in Indonesia.

  18. Optimizing the diagnostic testing of Clostridium difficile infection.

    Science.gov (United States)

    Bouza, Emilio; Alcalá, Luis; Reigadas, Elena

    2016-09-01

    Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and is associated with a considerable health and cost burden. However, there is still not a clear consensus on the best laboratory diagnosis approach and a wide variation of testing methods and strategies can be encountered. We aim to review the most practical aspects of CDI diagnosis providing our own view on how to optimize CDI diagnosis. Expert commentary: Laboratory diagnosis in search of C. difficile toxins should be applied to all fecal diarrheic samples reaching the microbiology laboratory in patients > 2 years old, with or without classic risk factors for CDI. Detection of toxins either directly in the fecal sample or in the bacteria isolated in culture confirm CDI in the proper clinical setting. Nuclear Acid Assay techniques (NAAT) allow to speed up the process with epidemiological and therapeutic consequences.

  19. Detection of seven virulence and toxin genes of Campylobacter jejuni isolates from Danish turkeys by PCR and cytolethal distending toxin production of the isolates

    DEFF Research Database (Denmark)

    Bang, Dang Duong; Borck, Birgitte; Nielsen, Eva Møller

    2004-01-01

    A total of 117 Campylobacter jejuni isolates from Danish turkeys were tested for the presence of seven virulence and toxin genes by PCR. One hundred seventeen (100%) isolates were positive for flaA, cadF, and ceuE gene primers. One hundred three (88%) isolates were positive for cdt gene cluster PCR.......7%) in Colon 205 assays, and 109 (93.2%) in chicken embryo cell assays. The CDT titers were determined in Vero cell assays. Of 117 isolates, 50 (42.7%) produced a CDT titer of 1:100, 29 (24.8%) of 1:50, and 27 (23%) of 1:5 to 1:10; 8 (6.8%) produced a CDT titer at undiluted supernatants and 3 (2.6%) produced...

  20. Proliferating Cell Nuclear Antigen-dependent Rapid Recruitment of Cdt1 and CRL4Cdt2 at DNA-damaged Sites after UV Irradiation in HeLa Cells*

    Science.gov (United States)

    Ishii, Takashi; Shiomi, Yasushi; Takami, Toshihiro; Murakami, Yusuke; Ohnishi, Naho; Nishitani, Hideo

    2010-01-01

    The licensing factor Cdt1 is degraded by CRL4Cdt2 ubiquitin ligase dependent on proliferating cell nuclear antigen (PCNA) during S phase and when DNA damage is induced in G1 phase. Association of both Cdt2 and PCNA with chromatin was observed in S phase and after UV irradiation. Here we used a micropore UV irradiation assay to examine Cdt2 accumulation at cyclobutane pyrimidine dimer-containing DNA-damaged sites in the process of Cdt1 degradation in HeLa cells. Cdt2, present in the nucleus throughout the cell cycle, accumulated rapidly at damaged DNA sites during G1 phase. The recruitment of Cdt2 is dependent on prior PCNA chromatin binding because Cdt2 association was prevented when PCNA was silenced. Cdt1 was also recruited to damaged sites soon after UV irradiation through its PIP-box. As Cdt1 was degraded, the Cdt2 signal at damaged sites was reduced, but PCNA, cyclobutane pyrimidine dimer, and XPA (xeroderma pigmentosum, complementation group A) signals remained at the same levels. These findings suggest that Cdt1 degradation following UV irradiation occurs rapidly at damaged sites due to PCNA chromatin loading and the recruitment of Cdt1 and CRL4Cdt2, before DNA damage repair is completed. PMID:20929861

  1. Cytolethal distending toxin: a conserved bacterial genotoxin that blocks cell cycle progression, leading to apoptosis of a broad range of mammalian cell lineages.

    Science.gov (United States)

    Jinadasa, Rasika N; Bloom, Stephen E; Weiss, Robert S; Duhamel, Gerald E

    2011-07-01

    Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important Gram-negative mucocutaneous bacterial pathogens. Irrespective of the bacterial species of origin, CDT causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. The active subunit CdtB has structural homology with the phosphodiesterase family of enzymes including mammalian DNase I, and alone is necessary and sufficient to account for cellular toxicity. Indeed, mammalian cells treated with CDT initiate a DNA damage response similar to that elicited by ionizing radiation-induced DNA double strand breaks resulting in cell cycle arrest and apoptosis. The mechanism of CDT-induced apoptosis remains incompletely understood, but appears to involve both p53-dependent and -independent pathways. While epithelial, endothelial and fibroblast cell lines respond to CDT by undergoing arrest of cell cycle progression resulting in nuclear and cytoplasmic distension that precedes apoptotic cell death, cells of haematopoietic origin display rapid apoptosis following a brief period of cell cycle arrest. In this review, the ecology of pathogens producing CDT, the molecular biology of bacterial CDT and the molecular mechanisms of CDT-induced cytotoxicity are critically appraised. Understanding the contribution of a broadly conserved bacterial genotoxin that blocks progression of the mammalian cell cycle, ultimately causing cell death, should assist with elucidating disease mechanisms for these important pathogens.

  2. Incorrect diagnosis of Clostridium difficile infection in a university hospital in Japan.

    Science.gov (United States)

    Mori, Nobuaki; Yoshizawa, Sadako; Saga, Tomoo; Ishii, Yoshikazu; Murakami, Hinako; Iwata, Morihiro; Collins, Deirdre A; Riley, Thomas V; Tateda, Kazuhiro

    2015-10-01

    Physicians often fail to suspect Clostridium difficile infection (CDI) and many microbiology laboratories use suboptimal diagnostic techniques. To estimate the extent of and reasons for incorrect diagnosis of CDI in Japan, we investigated toxigenic C. difficile isolated from all stool culture samples and clinical course. Over a 12-month period in 2010, all stool culture samples (n = 975) submitted from inpatients in a university hospital in Japan were cultured for C. difficile and routine microbiological testing was conducted. In total, 177 C. difficile isolates were recovered, and 127 isolates were toxigenic. Among the toxin-A-positive/toxin-B-positive isolates, 12 were also positive for the binary toxin gene. However, clinically important ribotypes, such as 027 and 078, were not identified. A total of 58 (45.7%) cases with toxigenic C. difficile had unformed stool, and the incidence CDI was 1.6 cases per 10,000 patient-days. Of these 58 cases, 40 were not diagnosed in routine testing due to a lack of clinical suspicion (24.1%, 14/58) or a negative C. difficile toxin assay result (44.8%, 26/58). A stool toxin assay was performed in 54 patients (78.2%, 54/69) who did not have unformed stool. The present study demonstrated that a significant number of CDI cases in Japan might be overlooked or misdiagnosed in clinical practice due to a lack of clinical suspicion and limitations of microbiological testing for CDI in Japan. Providing education to promote awareness of CDI among physicians is important to improve the accuracy of diagnosis in Japan. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  3. Prevalence, antibiogram, and cdt genes of toxigenic Campylobacter jejuni in salad style vegetables (ulam) at farms and retail outlets in Terengganu.

    Science.gov (United States)

    Khalid, Mohd Ikhsan; Tang, John Yew Huat; Baharuddin, Nabila Huda; Rahman, Nasiha Shakina; Rahimi, Nurul Faizzah; Radu, Son

    2015-01-01

    The present study was conducted to investigate the prevalence and antibiotic resistance among Campylobacter jejuni in ulam at farms and retail outlets located in Kuala Terengganu, Malaysia. A total of 526 samples (ulam, soil, and fertilizer) were investigated for the presence of C. jejuni and the gene for cytolethal distending toxin (cdt) by using a multiplex PCR method. Antibiotic susceptibility to 10 types of antibiotics was determined using the disk diffusion method for 33 C. jejuni isolates. The average prevalence of contaminated samples from farms, wet markets, and supermarkets was 35.29, 52.66, and 69.88%, respectively. The cdt gene was not detected in 24 of the 33 C. jejuni isolates, but 9 isolates harbored cdtC. Antibiotic resistance in C. jejuni isolates was highest to penicillin G (96.97% of isolates) followed by vancomycin (87.88%), ampicillin (75.76%), erythromycin (60.61%), tetracycline (9.09%), amikacin (6.06%), and norfloxacin (3.03%); none of the isolates were resistant to ciprofloxacin, enrofloxacin, and gentamicin. In this study, C. jejuni was present in ulam, and some isolates were highly resistant to some antibiotics but not to quinolones. Thus, appropriate attention and measures are required to prevent C. jejuni contamination on farms and at retail outlets.

  4. Immunization with Recombinant TcdB-Encapsulated Nanocomplex Induces Protection against Clostridium difficile Challenge in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Yi-Wen Liu

    2017-07-01

    Full Text Available Clostridium difficile is considered to be one of the major cause of infectious diarrhea in healthcare systems worldwide. Symptoms of C. difficile infection are caused largely by the production of two cytotoxins: toxin A (TcdA and toxin B (TcdB. Vaccine development is considered desirable as it would decrease the mounting medical costs and mortality associated with C. difficile infections. Biodegradable nanoparticles composed of poly-γ-glutamic acid (γ-PGA and chitosan have proven to be a safe and effective antigen delivery system for many viral vaccines. However, few studies have used this efficient antigen carrier for bacterial vaccine development. In this study, we eliminated the toxin activity domain of toxin B by constructing a recombinant protein rTcdB consists of residues 1852-2363 of TcdB receptor binding domain. The rTcdB was encapsulated in nanoparticles composed of γ-PGA and chitosan. Three rounds of intraperitoneal vaccination led to high anti-TcdB antibody responses and afforded mice full protection mice from lethal dose of C. difficile spore challenge. Protection was associated with high levels of toxin-neutralizing antibodies, and the rTcdB-encapsulated NPs elicited a longer-lasting antibody titers than antigen with the conventional adjuvant, aluminum hydroxide. Significant reductions in the level of proinflammatory cytokines and chemokines were observed in vaccinated mouse. These results suggested that polymeric nanocomplex-based vaccine design can be useful in developing vaccine against C. difficile infections.

  5. Prevalence of Clostridium difficile toxinotypes in infected patients at a tertiary care center in Lebanon.

    Science.gov (United States)

    Moukhaiber, Romy; Araj, George F; Kissoyan, Kohar Annie B; Cheaito, Katia A; Matar, Ghassan M

    2015-07-30

    Due to the increase in the incidence of Clostridium difficile associated diseases at a tertiary care center in Lebanon, this study was undertaken to determine the prevalent C. difficile toxinotypes. The immunocard method was used to test for toxins A and B in 88 collected stool samples, followed with API 20A to confirm for C. difficile. PCR amplification of the triose phosphate isomerase (tpi) gene, the toxin encoding genes tcdA, and tcdB, followed by toxinotyping, were performed on recovered isolates and stool specimens. Out of the 88 stool samples obtained, 30 (65.2%) were Immunocard positive, culture and or tpi positive for C. difficile. Of the 30 isolates, 4 were PCR negative for the tcdA and tcdB genes (A-B-), and 26 were PCR positive for the tcdA and / or tcdB genes with 4 being A+B+, 1 A+B-, and 21 A-B+. The results of toxinotyping showed that 2 isolates belonged to toxinotype 0, 4 to toxinotype XI, 2 to toxinotype XII, 1 to toxinotype XVI, 1(A+B-) and twenty (A-B+) designated as toxinotype 0-like. C. difficile was detected in 65.2% of patients' stools with prevalence of toxinotype 0-like. Identification of toxinotypes of C. difficile is important to determine the virulence potential of strains and control their spread.

  6. Clostridium difficile Infection in Production Animals and Avian Species: A Review.

    Science.gov (United States)

    Moono, Peter; Foster, Niki F; Hampson, David J; Knight, Daniel R; Bloomfield, Lauren E; Riley, Thomas V

    2016-12-01

    Clostridium difficile is the leading cause of antibiotic-associated diarrhea and colitis in hospitalized humans. Recently, C. difficile infection (CDI) has been increasingly recognized as a cause of neonatal enteritis in food animals such as pigs, resulting in stunted growth, delays in weaning, and mortality, as well as colitis in large birds such as ostriches. C. difficile is a strictly anaerobic spore-forming bacterium, which produces two toxins A (TcdA) and B (TcdB) as its main virulence factors. The majority of strains isolated from animals produce an additional binary toxin (C. difficile transferase) that is associated with increased virulence. C. difficile is ubiquitous in the environment and has a wide host range. This review summarizes the epidemiology, clinical presentations, risk factors, and laboratory diagnosis of CDI in animals. Increased awareness by veterinarians and animal owners of the significance of clinical disease caused by C. difficile in livestock and avians is needed. Finally, this review provides an overview on methods for controlling environmental contamination and potential therapeutics available.

  7. Clostridium difficile Infection

    Science.gov (United States)

    ... TeensRead MoreBMI Calculator Acute BronchitisHigh Blood PressureBursitis of the HipHigh CholesterolExercise-induced UrticariaMicroscopic HematuriaKidney CystsDe Quervain’s Tenosynovitis Home Diseases and Conditions Clostridium difficile (C. diff.) ...

  8. 2d CDT is 2d Horava-Lifshitz quantum gravity

    DEFF Research Database (Denmark)

    Ambjørn, J.; Glaser, L.; Sato, Y.

    2013-01-01

    Causal Dynamical Triangulations (CDT) is a lattice theory where aspects of quantum gravity can be studied. Two-dimensional CDT can be solved analytically and the continuum (quantum) Hamiltonian obtained. In this Letter we show that this continuum Hamiltonian is the one obtained by quantizing two......-dimensional projectable Horava-Lifshitz gravity....

  9. Sensitive and selective culture medium for detection of environmental Clostridium difficile isolates without requirement for anaerobic culture conditions.

    Science.gov (United States)

    Cadnum, Jennifer L; Hurless, Kelly N; Deshpande, Abhishek; Nerandzic, Michelle M; Kundrapu, Sirisha; Donskey, Curtis J

    2014-09-01

    Effective and easy-to-use methods for detecting Clostridium difficile spore contamination would be useful for identifying environmental reservoirs and monitoring the effectiveness of room disinfection. Culture-based detection methods are sensitive for detecting C. difficile, but their utility is limited due to the requirement of anaerobic culture conditions and microbiological expertise. We developed a low-cost selective broth medium containing thioglycolic acid and l-cystine, termed C. difficile brucella broth with thioglycolic acid and l-cystine (CDBB-TC), for the detection of C. difficile from environmental specimens under aerobic culture conditions. The sensitivity and specificity of CDBB-TC (under aerobic culture conditions) were compared to those of CDBB (under anaerobic culture conditions) for the recovery of C. difficile from swabs collected from hospital room surfaces. CDBB-TC was significantly more sensitive than CDBB for recovering environmental C. difficile (36/41 [88%] versus 21/41 [51%], respectively; P = 0.006). C. difficile latex agglutination, an enzyme immunoassay for toxins A and B or glutamate dehydrogenase, and a PCR for toxin B genes were all effective as confirmatory tests. For 477 total environmental cultures, the specificity of CDBB-TC versus that of CDBB based upon false-positive yellow-color development of the medium without recovery of C. difficile was 100% (0 false-positive results) versus 96% (18 false-positive results), respectively. False-positive cultures for CDBB were attributable to the growth of anaerobic non-C. difficile organisms that did not grow in CDBB-TC. Our results suggest that CDBB-TC provides a sensitive and selective medium for the recovery of C. difficile organisms from environmental samples, without the need for anaerobic culture conditions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  10. USP37 deubiquitinates Cdt1 and contributes to regulate DNA replication.

    Science.gov (United States)

    Hernández-Pérez, Santiago; Cabrera, Elisa; Amoedo, Hugo; Rodríguez-Acebes, Sara; Koundrioukoff, Stephane; Debatisse, Michelle; Méndez, Juan; Freire, Raimundo

    2016-10-01

    DNA replication control is a key process in maintaining genomic integrity. Monitoring DNA replication initiation is particularly important as it needs to be coordinated with other cellular events and should occur only once per cell cycle. Crucial players in the initiation of DNA replication are the ORC protein complex, marking the origin of replication, and the Cdt1 and Cdc6 proteins, that license these origins to replicate by recruiting the MCM2-7 helicase. To accurately achieve its functions, Cdt1 is tightly regulated. Cdt1 levels are high from metaphase and during G1 and low in S/G2 phases of the cell cycle. This control is achieved, among other processes, by ubiquitination and proteasomal degradation. In an overexpression screen for Cdt1 deubiquitinating enzymes, we isolated USP37, to date the first ubiquitin hydrolase controlling Cdt1. USP37 overexpression stabilizes Cdt1, most likely a phosphorylated form of the protein. In contrast, USP37 knock down destabilizes Cdt1, predominantly during G1 and G1/S phases of the cell cycle. USP37 interacts with Cdt1 and is able to de-ubiquitinate Cdt1 in vivo and, USP37 is able to regulate the loading of MCM complexes onto the chromatin. In addition, downregulation of USP37 reduces DNA replication fork speed. Taken together, here we show that the deubiquitinase USP37 plays an important role in the regulation of DNA replication. Whether this is achieved via Cdt1, a central protein in this process, which we have shown to be stabilized by USP37, or via additional factors, remains to be tested. Copyright © 2016 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  11. Genetic relatedness between Japanese and European isolates of Clostridium difficile originating from piglets and their risk associated with human health

    Directory of Open Access Journals (Sweden)

    Masaru eUsui

    2014-10-01

    Full Text Available Clostridium difficile colonization in pig intestine has been a public health concern. We analyzed C. difficile prevalence among piglets in Japan to clarify their origin and extent of the associated risk by using molecular and microbiological methods for both swine and human clinical isolates and foreign isolates. C. difficile was isolated from 120 neonatal piglet faecal samples. Toxin gene profile, antimicrobial susceptibilities, PCR ribotype, and multiple-locus variable-number tandem-repeat analysis (MLVA type of swine isolates were determined and compared with those of human clinical and foreign isolates. One-hundred C. difficile strains were isolated from 69 (57.5% samples, and 61 isolates (61% were toxin gene-positive. Some isolates were resistant to antimicrobials, contributing to antibiotic-associated diarrhoea by C. difficile. These results suggest that C. difficile, prevalent among Japanese pigs, is a potential risk for antibiotic-associated diarrhoea. Furthermore, PCR ribotype 078 (12 isolates, which has been linked to multiple outbreaks worldwide, was the third-most frequently isolated of the 14 PCR ribotypes identified. Moreover, MLVA revealed that all 12 PCR ribotype 078 isolates were genetically related to European PCR ribotype 078 strains found in both humans and pigs. To date, in Japan, many breeding pigs have been imported from European countries. The genetic relatedness of C. difficile isolates of Japanese swine origin to those of European origin suggests that they were introduced into Japan via imported pigs.

  12. Probiotic Saccharomyces boulardii CNCM I-745 prevents outbreak-associated Clostridium difficile-associated cecal inflammation in hamsters.

    Science.gov (United States)

    Koon, Hon Wai; Su, Bowei; Xu, Chunlan; Mussatto, Caroline C; Tran, Diana Hoang-Ngoc; Lee, Elaine C; Ortiz, Christina; Wang, Jiani; Lee, Jung Eun; Ho, Samantha; Chen, Xinhua; Kelly, Ciaran P; Pothoulakis, Charalabos

    2016-10-01

    C. difficile infection (CDI) is a common debilitating nosocomial infection associated with high mortality. Several CDI outbreaks have been attributed to ribotypes 027, 017, and 078. Clinical and experimental evidence indicates that the nonpathogenic yeast Saccharomyces boulardii CNCM I-745 (S.b) is effective for the prevention of CDI. However, there is no current evidence suggesting this probiotic can protect from CDI caused by outbreak-associated strains. We used established hamster models infected with outbreak-associated C. difficile strains to determine whether oral administration of live or heat-inactivated S.b can prevent cecal tissue damage and inflammation. Hamsters infected with C. difficile strain VPI10463 (ribotype 087) and outbreak-associated strains ribotype 017, 027, and 078 developed severe cecal inflammation with mucosal damage, neutrophil infiltration, edema, increased NF-κB phosphorylation, and increased proinflammatory cytokine TNFα protein expression. Oral gavage of live, but not heated, S.b starting 5 days before C. difficile infection significantly reduced cecal tissue damage, NF-κB phosphorylation, and TNFα protein expression caused by infection with all strains. Moreover, S.b-conditioned medium reduced cell rounding caused by filtered supernatants from all C. difficile strains. S.b-conditioned medium also inhibited toxin A- and B-mediated actin cytoskeleton disruption. S.b is effective in preventing C. difficile infection by outbreak-associated via inhibition of the cytotoxic effects of C. difficile toxins. Copyright © 2016 the American Physiological Society.

  13. Probiotic Saccharomyces boulardii CNCM I-745 prevents outbreak-associated Clostridium difficile-associated cecal inflammation in hamsters

    Science.gov (United States)

    Koon, Hon Wai; Su, Bowei; Xu, Chunlan; Mussatto, Caroline C.; Tran, Diana Hoang-Ngoc; Lee, Elaine C.; Ortiz, Christina; Wang, Jiani; Lee, Jung Eun; Ho, Samantha; Chen, Xinhua; Kelly, Ciaran P.

    2016-01-01

    C. difficile infection (CDI) is a common debilitating nosocomial infection associated with high mortality. Several CDI outbreaks have been attributed to ribotypes 027, 017, and 078. Clinical and experimental evidence indicates that the nonpathogenic yeast Saccharomyces boulardii CNCM I-745 (S.b) is effective for the prevention of CDI. However, there is no current evidence suggesting this probiotic can protect from CDI caused by outbreak-associated strains. We used established hamster models infected with outbreak-associated C. difficile strains to determine whether oral administration of live or heat-inactivated S.b can prevent cecal tissue damage and inflammation. Hamsters infected with C. difficile strain VPI10463 (ribotype 087) and outbreak-associated strains ribotype 017, 027, and 078 developed severe cecal inflammation with mucosal damage, neutrophil infiltration, edema, increased NF-κB phosphorylation, and increased proinflammatory cytokine TNFα protein expression. Oral gavage of live, but not heated, S.b starting 5 days before C. difficile infection significantly reduced cecal tissue damage, NF-κB phosphorylation, and TNFα protein expression caused by infection with all strains. Moreover, S.b-conditioned medium reduced cell rounding caused by filtered supernatants from all C. difficile strains. S.b-conditioned medium also inhibited toxin A- and B-mediated actin cytoskeleton disruption. S.b is effective in preventing C. difficile infection by outbreak-associated via inhibition of the cytotoxic effects of C. difficile toxins. PMID:27514478

  14. Prevalence of Clostridium difficile infection and colonization in a tertiary hospital and elderly community of North-Eastern Peninsular Malaysia.

    Science.gov (United States)

    Zainul, N H; Ma, Z F; Besari, A; Siti Asma, H; Rahman, R A; Collins, D A; Hamid, N; Riley, T V; Lee, Y Y

    2017-10-01

    Little is known about Clostridium difficile infection (CDI) in Asia. The aims of our study were to explore (i) the prevalence, risk factors and molecular epidemiology of CDI and colonization in a tertiary academic hospital in North-Eastern Peninsular Malaysia; (ii) the rate of carriage of C. difficile among the elderly in the region; (iii) the awareness level of this infection among the hospital staffs and students. For stool samples collected from hospital inpatients with diarrhea (n = 76) and healthy community members (n = 138), C. difficile antigen and toxins were tested by enzyme immunoassay. Stool samples were subsequently analyzed by culture and molecular detection of toxin genes, and PCR ribotyping of isolates. To examine awareness among hospital staff and students, participants were asked to complete a self-administered questionnaire. For the hospital and community studies, the prevalence of non-toxigenic C. difficile colonization was 16% and 2%, respectively. The prevalence of CDI among hospital inpatients with diarrhea was 13%. Out of 22 C. difficile strains from hospital inpatients, the toxigenic ribotypes 043 and 017 were most common (both 14%). In univariate analysis, C. difficile colonization in hospital inpatients was significantly associated with greater duration of hospitalization and use of penicillin (both P difficile colonization is prevalent in a Malaysian hospital setting but not in the elderly community with little or no contact with hospitals. Awareness of CDI is alarmingly poor.

  15. Vermin on pig farms are vectors for Clostridium difficile PCR ribotypes 078 and 045

    NARCIS (Netherlands)

    Burt, S.A.; Siemeling, L.; Kuijper, E.J.; Lipman, L.J.A.

    2012-01-01

    Clostridium difficile is a gram positive, spore forming, toxin producing, anaerobic bacteria and an opportunistic pathogen for Man and many animal species, causing diarrhea in young piglets. Piglets probably become colonized from the environment. To investigate the possible spread and transmission

  16. [Clinical and demographic profile and risk factors for Clostridium difficile infection].

    Science.gov (United States)

    Carvajal, Carlos; Pacheco, Carlos; Jaimes, Fabián

    2017-01-24

    Clostridium difficile infection is the leading cause of nosocomial infectious diarrhea. The increasing incidence added to a lower rate of response to the initial treatment and higher rates of relapse has generated a higher burden of the disease. To determine the clinical characteristics of hospitalized patients with C. difficile infection. We made a nested case-cohort study. We reviewed medical records of the patients with nosocomial diarrhea for whom an assay for toxin A-B of C. difficile had been requested from February, 2010, to February, 2012. We defined case as a patient with diarrhea and a positive assay for the toxin, and control as those patients with a negative assay for the toxin. We collected data on demographic and clinical characteristics, risk factors, hospital length of stay, treatment, and complications. We collected data from 123 patients during the follow-up period, 30 of whom were positive for the toxin. Mean age in the study population was 49 years and 60% were men. The main symptoms were abdominal pain (35%) and fever (34%). The principal complications were electrolytic alteration and severe sepsis with secondary acute kidney injury. Mortality was 13% and independent factors associated to the appearance of the infection were the use of proton pump inhibitors and previous gastrointestinal tract surgery. The use of proton pump inhibitors and previous gastrointestinal tract surgery were factors associated to C. difficile infection.

  17. Rapid change of fecal microbiome and disappearance of Clostridium difficile in a colonized infant after transition from breast milk to cow milk.

    Science.gov (United States)

    Davis, Manli Y; Zhang, Husen; Brannan, Lera E; Carman, Robert J; Boone, James H

    2016-10-07

    Clostridium difficile is the most common known cause of antibiotic-associated diarrhea. Upon the disturbance of gut microbiota by antibiotics, C. difficile establishes growth and releases toxins A and B, which cause tissue damage in the host. The symptoms of C. difficile infection disease range from mild diarrhea to pseudomembranous colitis and toxic megacolon. Interestingly, 10-50 % of infants are asymptomatic carriers of C. difficile. This longitudinal study of the C. difficile colonization in an infant revealed the dynamics of C. difficile presence in gut microbiota. Fifty fecal samples, collected weekly between 5.5 and 17 months of age from a female infant who was an asymptomatic carrier of C. difficile, were analyzed by 16S rRNA gene sequencing. Colonization switching between toxigenic and non-toxigenic C. difficile strains as well as more than 100,000-fold fluctuations of C. difficile counts were observed. C. difficile toxins were detected during the testing period in some infant stool samples, but the infant never had diarrhea. Although fecal microbiota was stable during breast feeding, a dramatic and permanent change of microbiota composition was observed within 5 days of the transition from human milk to cow milk. A rapid decline and eventual disappearance of C. difficile coincided with weaning at 12.5 months. An increase in the relative abundance of Bacteroides spp., Blautia spp., Parabacteroides spp., Coprococcus spp., Ruminococcus spp., and Oscillospira spp. and a decrease of Bifidobacterium spp., Lactobacillus spp., Escherichia spp., and Clostridium spp. were observed during weaning. The change in microbiome composition was accompanied by a gradual increase of fecal pH from 5.5 to 7. The bacterial groups that are less abundant in early infancy, and that increase in relative abundance after weaning, likely are responsible for the expulsion of C. difficile.

  18. Cost-effectiveness of a modified two-step algorithm using a combined glutamate dehydrogenase/toxin enzyme immunoassay and real-time PCR for the diagnosis of Clostridium difficile infection.

    Science.gov (United States)

    Vasoo, Shawn; Stevens, Jane; Portillo, Lena; Barza, Ruby; Schejbal, Debra; Wu, May May; Chancey, Christina; Singh, Kamaljit

    2014-02-01

    The analytical performance and cost-effectiveness of the Wampole Toxin A/B EIA, the C. Diff. Quik Chek Complete (CdQCC) (a combined glutamate dehydrogenase antigen/toxin enzyme immunoassay), two RT-PCR assays (Progastro Cd and BD GeneOhm) and a modified two-step algorithm using the CdQCC reflexed to RT-PCR for indeterminate results were compared. The sensitivity of the Wampole Toxin A/B EIA, CdQCC (GDH antigen), BD GeneOhm and Progastro Cd RT-PCR were 85.4%, 95.8%, 100% and 93.8%, respectively. The algorithm provided rapid results for 86% of specimens and the remaining indeterminate results were resolved by RT-PCR, offering the best balance of sensitivity and cost savings per test (algorithm ∼US$13.50/test versus upfront RT-PCR ∼US$26.00/test). Copyright © 2012. Published by Elsevier B.V.

  19. First confirmed case of Clostridium difficile-associated diarrhea in foals in Brazil Primeiro relato de diarreia associada à Clostridium difficile em potros no Brasil

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    Rodrigo Otávio Silveira Silva

    2012-03-01

    Full Text Available Despite of the substantial role of Clostridium difficile in causing diarrhea and colitis in foals, there have been no confirmed diagnoses of disease caused by this bacteria in Brazil. In this paper, we describe confirmed cases of colitis caused by C. difficile in two foals in Brazil. Two five-month-old foals with a five-day history of diarrhea after antibiotic treatment for a respiratory disease were treated at the Veterinary Hospital of the Universidade Federal de Minas Gerais. C. difficile A/B toxins were detected, and toxigenic strains of C. difficile were isolated from the foals' feces. The treatment was based on fluid therapy and antibiotics (metronidazole and ceftiofur, and the animals experienced a gradual recovery. The association between the medical history, clinical signs, laboratory exam results and therapeutic success confirmed the diagnosis of C. difficile-associated diarrhea. The present report raises the possibility that C. difficile is also a pathogen in equines in Brazil and highlights the need for up to date routine laboratory protocols for the diagnosis of this disease.Apesar da importância de Clostridium difficile como agente causador de diarreia e colite em potros, inexistem relatos confirmados de tal doença no Brasil. O objetivo deste trabalho foi descrever dois casos confirmados de diarreia causados por C. difficile em potros, ocorridos em Minas Gerais, Brasil. Os animais, com cinco meses de idade, foram encaminhados ao Hospital Veterinário da Universidade Federal de Minas Gerais (UFMG com histórico de cinco dias de diarreia após antibioticoterapia com penicilina para uma possível pneumonia. Ambos os animais foram positivos para detecção das toxinas A/B de C. difficile e isolados toxigênicas de C. difficile foram isoladas de amostras de fezes. Os animais apresentaram melhora gradual com o tratamento baseado em metronidazol e fluidoterapia e receberam alta após sete dias. A associação do quadro clínico, exames

  20. Clostridium difficile infection: epidemiology, diagnosis and understanding transmission.

    Science.gov (United States)

    Martin, Jessica S H; Monaghan, Tanya M; Wilcox, Mark H

    2016-04-01

    Clostridium difficile infection (CDI) continues to affect patients in hospitals and communities worldwide. The spectrum of clinical disease ranges from mild diarrhoea to toxic megacolon, colonic perforation and death. However, this bacterium might also be carried asymptomatically in the gut, potentially leading to 'silent' onward transmission. Modern technologies, such as whole-genome sequencing and multi-locus variable-number tandem-repeat analysis, are helping to track C. difficile transmission across health-care facilities, countries and continents, offering the potential to illuminate previously under-recognized sources of infection. These typing strategies have also demonstrated heterogeneity in terms of CDI incidence and strain types reflecting different stages of epidemic spread. However, comparison of CDI epidemiology, particularly between countries, is challenging due to wide-ranging approaches to sampling and testing. Diagnostic strategies for C. difficile are complicated both by the wide range of bacterial targets and tests available and the need to differentiate between toxin-producing and non-toxigenic strains. Multistep diagnostic algorithms have been recommended to improve sensitivity and specificity. In this Review, we describe the latest advances in the understanding of C. difficile epidemiology, transmission and diagnosis, and discuss the effect of these developments on the clinical management of CDI.

  1. Current knowledge on the laboratory diagnosis of Clostridium difficile infection.

    Science.gov (United States)

    Martínez-Meléndez, Adrián; Camacho-Ortiz, Adrián; Morfin-Otero, Rayo; Maldonado-Garza, Héctor Jesús; Villarreal-Treviño, Licet; Garza-González, Elvira

    2017-03-07

    Clostridium difficile ( C. difficile ) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

  2. Lactobacillus delbrueckii ssp. bulgaricus B-30892 can inhibit cytotoxic effects and adhesion of pathogenic Clostridium difficile to Caco-2 cells

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    Banerjee Pratik

    2009-04-01

    Full Text Available Abstract Background Probiotic microorganisms are receiving increasing interest for use in the prevention, treatment, or dietary management of certain diseases, including antibiotic-associated diarrhea (AAD. Clostridium difficile is the most common cause of AAD and the resulting C. difficile – mediated infection (CDI, is potentially deadly. C. difficile associated diarrhea (CDAD is manifested by severe inflammation and colitis, mostly due to the release of two exotoxins by C. difficile causing destruction of epithelial cells in the intestine. The aim of this study was to determine the effect of probiotic bacteria Lactobacillus delbrueckii ssp. bulgaricus B-30892 (LDB B-30892 on C. difficile-mediated cytotoxicity using Caco-2 cells as a model. Methods Experiments were carried out to test if the cytotoxicity induced by C. difficile-conditioned-medium on Caco-2 cells can be altered by cell-free supernatant (CFS from LDB B-30892 in different dilutions (1:2 to 1:2048. In a similar experimental setup, comparative evaluations of other probiotic strains were made by contrasting the results from these strains with the results from LDB B-30892, specifically the ability to affect C. difficile induced cytotoxicity on Caco-2 monolayers. Adhesion assays followed by quantitative analysis by Giemsa staining were conducted to test if the CFSs from LDB B-30892 and other probiotic test strains have the capability to alter the adhesion of C. difficile to the Caco-2 monolayer. Experiments were also performed to evaluate if LDB B-30892 or its released components have any bactericidal effect on C. difficile. Results and discussion Co-culturing of LDB B-30892 with C. difficile inhibited the C. difficile-mediated cytotoxicity on Caco-2 cells. When CFS from LDB B-30892-C. difficile co-culture was administered (up to a dilution of 1:16 on Caco-2 monolayer, there were no signs of cytotoxicity. When CFS from separately grown LDB B-30892 was mixed with the cell-free toxin

  3. Lactobacillus delbrueckii ssp. bulgaricus B-30892 can inhibit cytotoxic effects and adhesion of pathogenic Clostridium difficile to Caco-2 cells

    Science.gov (United States)

    Banerjee, Pratik; Merkel, Glenn J; Bhunia, Arun K

    2009-01-01

    Background Probiotic microorganisms are receiving increasing interest for use in the prevention, treatment, or dietary management of certain diseases, including antibiotic-associated diarrhea (AAD). Clostridium difficile is the most common cause of AAD and the resulting C. difficile – mediated infection (CDI), is potentially deadly. C. difficile associated diarrhea (CDAD) is manifested by severe inflammation and colitis, mostly due to the release of two exotoxins by C. difficile causing destruction of epithelial cells in the intestine. The aim of this study was to determine the effect of probiotic bacteria Lactobacillus delbrueckii ssp. bulgaricus B-30892 (LDB B-30892) on C. difficile-mediated cytotoxicity using Caco-2 cells as a model. Methods Experiments were carried out to test if the cytotoxicity induced by C. difficile-conditioned-medium on Caco-2 cells can be altered by cell-free supernatant (CFS) from LDB B-30892 in different dilutions (1:2 to 1:2048). In a similar experimental setup, comparative evaluations of other probiotic strains were made by contrasting the results from these strains with the results from LDB B-30892, specifically the ability to affect C. difficile induced cytotoxicity on Caco-2 monolayers. Adhesion assays followed by quantitative analysis by Giemsa staining were conducted to test if the CFSs from LDB B-30892 and other probiotic test strains have the capability to alter the adhesion of C. difficile to the Caco-2 monolayer. Experiments were also performed to evaluate if LDB B-30892 or its released components have any bactericidal effect on C. difficile. Results and discussion Co-culturing of LDB B-30892 with C. difficile inhibited the C. difficile-mediated cytotoxicity on Caco-2 cells. When CFS from LDB B-30892-C. difficile co-culture was administered (up to a dilution of 1:16) on Caco-2 monolayer, there were no signs of cytotoxicity. When CFS from separately grown LDB B-30892 was mixed with the cell-free toxin preparation (CFT) of

  4. Detection of toxigenic Clostridium difficile in paediatric patients.

    Science.gov (United States)

    Falces-Romero, Iker; Troyano-Hernáez, Paloma; García-Bujalance, Silvia; Baquero-Artigao, Fernando; Mellado-Peña, María José; García-Rodríguez, Julio

    2017-07-06

    Our main objective was a revision of clinical, microbiological and epidemiological results of Clostridium difficile-associated infection in paediatric patients (2010-2015). We compared the diagnoses performed by detection of toxins in feces and those performed by real-time PCR. This retrospective study included 82 paediatric patients. Detection of toxigenic C. difficile was performed sequentially, in diarrheal feces and under clinical request. A total of 39% of the patients were attended at Haematology-oncology Unit and >50% of them had previously received cephalosporins. Fever associated with diarrhea was more frequent in the group of toxin detection, whereas not receiving specific antibiotic treatment was more frequent in the group of positive PCR, without statistically significant differences. We highlight the presence of C. difficile infection in children under 2years old. A diagnostic testing in selected paediatric patients would be advisable when there is clinical suspicion of infection. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  5. Burden of Clostridium difficile infection in the United States.

    Science.gov (United States)

    Lessa, Fernanda C; Mu, Yi; Bamberg, Wendy M; Beldavs, Zintars G; Dumyati, Ghinwa K; Dunn, John R; Farley, Monica M; Holzbauer, Stacy M; Meek, James I; Phipps, Erin C; Wilson, Lucy E; Winston, Lisa G; Cohen, Jessica A; Limbago, Brandi M; Fridkin, Scott K; Gerding, Dale N; McDonald, L Clifford

    2015-02-26

    The magnitude and scope of Clostridium difficile infection in the United States continue to evolve. In 2011, we performed active population- and laboratory-based surveillance across 10 geographic areas in the United States to identify cases of C. difficile infection (stool specimens positive for C. difficile on either toxin or molecular assay in residents ≥ 1 year of age). Cases were classified as community-associated or health care-associated. In a sample of cases of C. difficile infection, specimens were cultured and isolates underwent molecular typing. We used regression models to calculate estimates of national incidence and total number of infections, first recurrences, and deaths within 30 days after the diagnosis of C. difficile infection. A total of 15,461 cases of C. difficile infection were identified in the 10 geographic areas; 65.8% were health care-associated, but only 24.2% had onset during hospitalization. After adjustment for predictors of disease incidence, the estimated number of incident C. difficile infections in the United States was 453,000 (95% confidence interval [CI], 397,100 to 508,500). The incidence was estimated to be higher among females (rate ratio, 1.26; 95% CI, 1.25 to 1.27), whites (rate ratio, 1.72; 95% CI, 1.56 to 2.0), and persons 65 years of age or older (rate ratio, 8.65; 95% CI, 8.16 to 9.31). The estimated number of first recurrences of C. difficile infection was 83,000 (95% CI, 57,000 to 108,900), and the estimated number of deaths was 29,300 (95% CI, 16,500 to 42,100). The North American pulsed-field gel electrophoresis type 1 (NAP1) strain was more prevalent among health care-associated infections than among community-associated infections (30.7% vs. 18.8%, Pdifficile was responsible for almost half a million infections and was associated with approximately 29,000 deaths in 2011. (Funded by the Centers for Disease Control and Prevention.).

  6. Cdt1 is differentially targeted for degradation by anticancer chemotherapeutic drugs.

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    Athanasia Stathopoulou

    Full Text Available BACKGROUND: Maintenance of genome integrity is crucial for the propagation of the genetic information. Cdt1 is a major component of the pre-replicative complex, which controls once per cell cycle DNA replication. Upon DNA damage, Cdt1 is rapidly targeted for degradation. This targeting has been suggested to safeguard genomic integrity and prevent re-replication while DNA repair is in progress. Cdt1 is deregulated in tumor specimens, while its aberrant expression is linked with aneuploidy and promotes tumorigenesis in animal models. The induction of lesions in DNA is a common mechanism by which many cytotoxic anticancer agents operate, leading to cell cycle arrest and apoptosis. METHODOLOGY/PRINCIPAL FINDING: In the present study we examine the ability of several anticancer drugs to target Cdt1 for degradation. We show that treatment of HeLa and HepG2 cells with MMS, Cisplatin and Doxorubicin lead to rapid proteolysis of Cdt1, whereas treatment with 5-Fluorouracil and Tamoxifen leave Cdt1 expression unaffected. Etoposide affects Cdt1 stability in HepG2 cells and not in HeLa cells. RNAi experiments suggest that Cdt1 proteolysis in response to MMS depends on the presence of the sliding clamp PCNA. CONCLUSION/SIGNIFICANCE: Our data suggest that treatment of tumor cells with commonly used chemotherapeutic agents induces differential responses with respect to Cdt1 proteolysis. Information on specific cellular targets in response to distinct anticancer chemotherapeutic drugs in different cancer cell types may contribute to the optimization of the efficacy of chemotherapy.

  7. Clostridium difficile with Moxifloxacin/Clindamycin Resistance in Vegetables in Ohio, USA, and Prevalence Meta-Analysis

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    Alex Rodriguez-Palacios

    2014-01-01

    Full Text Available We (i determined the prevalence of Clostridium difficile and their antimicrobial resistance to six antimicrobial classes, in a variety of fresh vegetables sold in retail in Ohio, USA, and (ii conducted cumulative meta-analysis of reported prevalence in vegetables since the 1990s. Six antimicrobial classes were tested for their relevance as risk factors for C. difficile infections (CDIs (clindamycin, moxifloxacin or their clinical priority as exhaustive therapeutic options (metronidazole, vancomycin, linezolid, and tigecycline. By using an enrichment protocol we isolated C. difficile from three of 125 vegetable products (2.4%. All isolates were toxigenic, and originated from 4.6% of 65 vegetables cultivated above the ground (n=3; outer leaves of iceberg lettuce, green pepper, and eggplant. Root vegetables yielded no C. difficile. The C. difficile isolates belonged to two PCR ribotypes, one with an unusual antimicrobial resistance for moxifloxacin and clindamycin (lettuce and pepper; 027-like, A+B+CDT+; tcdC 18 bp deletion; the other PCR ribotype (eggplant, A+B+ CDT−; classic tcdC was susceptible to all antimicrobials. Results of the cumulative weighted meta-analysis (6 studies indicate that the prevalence of C. difficile in vegetables is 2.1% and homogeneous (P<0.001 since the first report in 1996 (2.4%. The present study is the first report of the isolation of C. difficile from retail vegetables in the USA. Of public health relevance, antimicrobial resistance to moxifloxacin/clindamycin (a bacterial-associated risk factor for severe CDIs was identified on the surface of vegetables that are consumed raw.

  8. Human CDT1 associates with CDC7 and recruits CDC45 to chromatin during S phase

    DEFF Research Database (Denmark)

    Ballabeni, Andrea; Zamponi, Raffaela; Caprara, Greta

    2009-01-01

    The initiation of DNA replication is a tightly controlled process that involves the formation of distinct complexes at origins of DNA replication at specific periods of the cell cycle. Pre-Replicative Complexes are formed during telophase and early G1. They rearrange at the start of S phase to form...... pre-Initiation Complexes, which are a prerequisite for DNA replication. The CDT1 protein is required for the formation of the pre-Replicative Complexes. Here we show that human CDT1 associates with the CDC7 kinase and recruits CDC45 to chromatin. Moreover, we show that the amount of CDT1 bound...

  9. Surface-layer protein A (SlpA is a major contributor to host-cell adherence of Clostridium difficile.

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    Michelle M Merrigan

    Full Text Available Clostridium difficile is a leading cause of antibiotic-associated diarrhea, and a significant etiologic agent of healthcare-associated infections. The mechanisms of attachment and host colonization of C. difficile are not well defined. We hypothesize that non-toxin bacterial factors, especially those facilitating the interaction of C. difficile with the host gut, contribute to the initiation of C. difficile infection. In this work, we optimized a completely anaerobic, quantitative, epithelial-cell adherence assay for vegetative C. difficile cells, determined adherence proficiency under multiple conditions, and investigated C. difficile surface protein variation via immunological and DNA sequencing approaches focused on Surface-Layer Protein A (SlpA. In total, thirty-six epidemic-associated and non-epidemic associated C. difficile clinical isolates were tested in this study, and displayed intra- and inter-clade differences in attachment that were unrelated to toxin production. SlpA was a major contributor to bacterial adherence, and individual subunits of the protein (varying in sequence between strains mediated host-cell attachment to different extents. Pre-treatment of host cells with crude or purified SlpA subunits, or incubation of vegetative bacteria with anti-SlpA antisera significantly reduced C. difficile attachment. SlpA-mediated adherence-interference correlated with the attachment efficiency of the strain from which the protein was derived, with maximal blockage observed when SlpA was derived from highly adherent strains. In addition, SlpA-containing preparations from a non-toxigenic strain effectively blocked adherence of a phylogenetically distant, epidemic-associated strain, and vice-versa. Taken together, these results suggest that SlpA plays a major role in C. difficile infection, and that it may represent an attractive target for interventions aimed at abrogating gut colonization by this pathogen.

  10. Effect of biotherapeutics on antitoxin IgG in experimentally induced Clostridium difficile infection

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    S Kaur

    2012-01-01

    Full Text Available Purpose: Recurrent diarrhoea after successful treatment of primary Clostridium difficile associated disease (CDAD occurs due to bowel flora alterations and failure to mount an effective antibody response. Apart from antibiotics, risk factors include immunosuppressive and acid-suppressive drug administration. Biotherapeutics such as probiotic and epidermal growth factor (EGF may offer potential effective therapy for CDAD. Materials and Methods: The effect of biotherapeutics in mounting an antibody response against C. difficile toxins was studied in BALB/c mice challenged with C. difficile after pre-treatment with ampicillin, lansoprazole or cyclosporin. Sera from sacrificed animals were estimated for antitoxin IgG by enzyme linked immunosorbent assay. Results: Antitoxin IgG was significantly higher (P0.05 in animals in which C. difficile was given after pre-treatment with cyclosporin compared to those without any pre-treatment, or pre-treatment with antibiotic or lansoprazole. In inter-subgroup comparisons also significant anomaly in production of antitoxin IgG was found. The antitoxin IgG levels were raised in animals administered C. difficile after pre-treatment with ampicillin, but lower in animals administered cyclosporin. High levels of antitoxin IgG were also found in the serum samples of animals receiving lansoprazole and C. difficile. Conclusions: Probiotics showed their beneficial effect by boosting the immune response as seen by production of antitoxin IgG. Oral administration of EGF did not affect the immune response to C. difficile toxins as significant increase was not observed in the serum antitoxin IgG levels in any of the groups investigated.

  11. A Clostridium difficile Cell Wall Glycopolymer Locus Influences Bacterial Shape, Polysaccharide Production and Virulence.

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    Michele Chu

    2016-10-01

    Full Text Available Clostridium difficile is a diarrheagenic pathogen associated with significant mortality and morbidity. While its glucosylating toxins are primary virulence determinants, there is increasing appreciation of important roles for non-toxin factors in C. difficile pathogenesis. Cell wall glycopolymers (CWGs influence the virulence of various pathogens. Five C. difficile CWGs, including PSII, have been structurally characterized, but their biosynthesis and significance in C. difficile infection is unknown. We explored the contribution of a conserved CWG locus to C. difficile cell-surface integrity and virulence. Attempts at disrupting multiple genes in the locus, including one encoding a predicted CWG exporter mviN, were unsuccessful, suggesting essentiality of the respective gene products. However, antisense RNA-mediated mviN downregulation resulted in slight morphology defects, retarded growth, and decreased surface PSII deposition. Two other genes, lcpA and lcpB, with putative roles in CWG anchoring, could be disrupted by insertional inactivation. lcpA- and lcpB- mutants had distinct phenotypes, implying non-redundant roles for the respective proteins. The lcpB- mutant was defective in surface PSII deposition and shedding, and exhibited a remodeled cell surface characterized by elongated and helical morphology, aberrantly-localized cell septae, and an altered surface-anchored protein profile. Both lcpA- and lcpB- strains also displayed heightened virulence in a hamster model of C. difficile disease. We propose that gene products of the C. difficile CWG locus are essential, that they direct the production/assembly of key antigenic surface polysaccharides, and thereby have complex roles in virulence.

  12. Fidaxomicin for the treatment of Clostridium difficile infections.

    Science.gov (United States)

    Whitman, Craig B; Czosnowski, Quinn A

    2012-02-01

    To evaluate the pharmacology, microbiology, safety, and efficacy of fidaxomicin for treatment of Clostridium difficile infections (CDI). Literature was identified through Ovid MEDLINE (1948-December 2011) and International Pharmaceutical Abstracts (1970-December 2011) using the search terms fidaxomicin, OPT-80, PAR-101, OP-118, difimicin, tiacumicin, lipiarmycin, Clostridium difficile, Clostridium difficile infection, Clostridium difficile-associated diarrhea, and cost. Drug monographs were retrieved from manufacturers' Web pages, and the Red Book component of Micromedex was used for cost information. All pertinent Phase 1, 2, and 3 studies published in English were included. Fidaxomicin is a macrocyclic compound bactericidal against C. difficile and inhibits toxin and spore production. It has poor oral absorption with high fecal concentrations. Available Phase 2 and 3 data with fidaxomicin 200 mg orally every 12 hours demonstrate similar effectiveness in treating CDI compared to oral vancomycin. Fidaxomicin was shown to have less frequency of recurrent infections. Adverse effects are uncommon and occur at similar rates as with oral vancomycin. The most frequently reported adverse effects are gastrointestinal, hematologic, and electrolyte disorders. Available data are lacking in several areas, including the efficacy and safety of fidaxomicin compared to established regimens for mild-to-moderate, life-threatening, and recurrent CDIs. The cost of a 10-day course of fidaxomicin is significantly more than that of metronidazole and vancomycin for treatment of mild-to-moderate CDI. Fidaxomicin appears to be an effective and safe alternative to oral vancomycin for treatment of mild-to-moderate and severe CDI. Data on its use compared to guideline-recommended therapies for mild-to-moderate and life-threatening CDI are needed. Further data assessing the cost-effectiveness of fidaxomicin are needed. Currently, it cannot be recommended over vancomycin for treatment of CDI

  13. Clostridium difficile Infection Among US Emergency Department Patients With Diarrhea and No Vomiting.

    Science.gov (United States)

    Abrahamian, Fredrick M; Talan, David A; Krishnadasan, Anusha; Citron, Diane M; Paulick, Ashley L; Anderson, Lydia J; Goldstein, Ellie J C; Moran, Gregory J

    2017-07-01

    The incidence of Clostridium difficile infection has increased and has been observed among persons from the community who have not been exposed to antibiotics or health care settings. Our aims are to determine prevalence of C difficile infection among emergency department (ED) patients with diarrhea and the prevalence among patients without traditional risk factors. We conducted a prospective observational study of patients aged 2 years or older with diarrhea (≥3 episodes/24 hours) and no vomiting in 10 US EDs (2010 to 2013). We confirmed C difficile infection by positive stool culture result and toxin assay. C difficile infection risk factors were antibiotic use or overnight health care stay in the previous 3 months or previous C difficile infection. We typed strains with pulsed-field gel electrophoresis. Of 422 participants, median age was 46 years (range 2 to 94 years), with median illness duration of 3.0 days and 43.4% having greater than or equal to 10 episodes of diarrhea during the previous 24 hours. At least one risk factor for C difficile infection was present in 40.8% of participants; 25.9% were receiving antibiotics, 26.9% had health care stay within the previous 3 months, and 3.3% had previous C difficile infection. Forty-three participants (10.2%) had C difficile infection; among these, 24 (55.8%) received antibiotics and 19 (44.2%) had health care exposure; 17 of 43 (39.5%) lacked any risk factor. Among participants without risk factors, C difficile infection prevalence was 6.9%. The most commonly identified North American pulsed-field gel electrophoresis (NAP) strains were NAP type 1 (23.3%) and NAP type 4 (16.3%). Among mostly adults presenting to US EDs with diarrhea and no vomiting, C difficile infection accounted for approximately 10%. More than one third of patients with C difficile infection lacked traditional risk factors for the disease. Among participants without traditional risk factors, prevalence of C difficile infection was

  14. The zoonotic potential of Clostridium difficile from small companion animals and their owners.

    Science.gov (United States)

    Rabold, Denise; Espelage, Werner; Abu Sin, Muna; Eckmanns, Tim; Schneeberg, Alexander; Neubauer, Heinrich; Möbius, Nadine; Hille, Katja; Wieler, Lothar H; Seyboldt, Christian; Lübke-Becker, Antina

    2018-01-01

    Clostridium difficile infections (CDI) in humans range from asymptomatic carriage to life-threatening intestinal disease. Findings on C. difficile in various animal species and an overlap in ribotypes (RTs) suggest potential zoonotic transmission. However, the impact of animals for human CDI remains unclear. In a large-scale survey we collected 1,447 fecal samples to determine the occurrence of C. difficile in small companion animals (dogs and cats) and their owners and to assess potential epidemiological links within the community. The Germany-wide survey was conducted from July 2012-August 2013. PCR ribotyping, Multilocus VNTR Analysis (MLVA) and PCR detection of toxin genes were used to characterize isolated C. difficile strains. A database was defined and logistic regression used to identify putative factors associated with fecal shedding of C. difficile. In total, 1,418 samples met the inclusion criteria. The isolation rates for small companion animals and their owners within the community were similarly low with 3.0% (25/840) and 2.9% (17/578), respectively. PCR ribotyping revealed eight and twelve different RTs in animals and humans, respectively, whereas three RTs were isolated in both, humans and animals. RT 014/0, a well-known human hospital-associated lineage, was predominantly detected in animal samples. Moreover, the potentially highly pathogenic RTs 027 and 078 were isolated from dogs. Even though, C. difficile did not occur simultaneously in animals and humans sharing the same household. The results of the epidemiological analysis of factors associated with fecal shedding of C. difficile support the hypothesis of a zoonotic potential. Molecular characterization and epidemiological analysis revealed that the zoonotic risk for C. difficile associated with dogs and cats within the community is low but cannot be excluded.

  15. Prevalence of Clostridium Difficile Infection in Patients After Radical Cystectomy and Neoadjuvant Chemotherapy.

    Science.gov (United States)

    Cotter, Katherine J; Fan, Yunhua; Sieger, Gretchen K; Weight, Christopher J; Konety, Badrinath R

    2017-10-27

    Clostridium Difficile is the most common cause of nosocomial infectious diarrhea. This study evaluates the prevalence and predictors of Clostridium Difficile infections in patients undergoing radical cystectomy with or without neoadjuvant chemotherapy. Retrospective chart review was performed of all patients undergoing cystectomy and urinary diversion at a single institution from 2011-2017. Infection was documented in all cases with testing for Clostridium Difficile polymerase chain reaction toxin B. Patient and disease related factors were compared for those who received neoadjuvant chemotherapy vs. those who did not in order to identify potential risk factors associated with C. Difficile infections. Chi squared test and logistic regression analysis were used to determine statistical significance. Of 350 patients who underwent cystectomy, 41 (11.7%) developed Clostridium Difficile in the 30 day post-operative period. The prevalence of C. Difficile infection was higher amongst the patients undergoing cystectomy compared to the non-cystectomy admissions at our hospital (11.7 vs. 2.9%). Incidence was not significantly different among those who underwent cystectomy for bladder cancer versus those who underwent the procedure for other reasons. Median time to diagnosis was 6 days (range 3-28 days). The prevalence of C. Diff infections was not significantly different among those who received neoadjuvant chemotherapy vs. those who did not (11% vs. 10.4% p  = 0.72). A significant association between C. Difficile infection was not seen with proton pump inhibitor use ( p  = 0.48), patient BMI ( p  = 0.67), chemotherapeutic regimen ( p  = 0.94), individual surgeon ( p  = 0.54), type of urinary diversion (0.41), or peri-operative antibiotic redosing ( p  = 0.26). Clostridium Difficile infection has a higher prevalence in patients undergoing cystectomy. No significant association between prevalence and exposure to neoadjuvant chemotherapy was seen.

  16. Clostridium difficile: methods and protocols

    National Research Council Canada - National Science Library

    Mullany, Peter; Roberts, Adam P

    2010-01-01

    .... difficile research to describe the recently developed methods for studying the organism. These range from methods for isolation of the organism, molecular typing, genomics, genetic manipulation, and the use of animal models...

  17. Clostridium perfringens and C. difficile in parvovirus-positive dogs.

    Science.gov (United States)

    Silva, Rodrigo Otávio Silveira; Dorella, Fernanda Alves; Figueiredo, Henrique Cesar Pereira; Costa, Érica Azevedo; Pelicia, Vanessa; Ribeiro, Bruna Letícia Devidé; Ribeiro, Marcio Garcia; Paes, Antonio Carlos; Megid, Jane; Lobato, Francisco Carlos Faria

    2017-12-01

    The aim of this study was to investigate Clostridium difficile and Clostridium perfringens in 82 diarrheic dogs positive for canine parvovirus type 2 (CPV). Enterotoxigenic C. perfringens type A was isolated from three (3.6%) dogs. One (1.2%) strain was also positive for NetE- and NetF-encoding genes, which are commonly associated with diarrhea in dogs. Toxigenic C. difficile was isolated from one animal (1.2%), which was also positive for A/B toxins. The present study identified C. difficile and C. perfringens infection in CPV-positive dogs. Further studies are necessary to clarify if clostridial infections may predispose or potentiate CPV-infection in dogs or vice versa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Fatal course of takotsubo cardiomyopathy in a female with recurrent Clostridium difficile infection.

    Science.gov (United States)

    Elikowski, Waldemar; Małek-Elikowska, Małgorzata; Lisiecka, Monika; Mozer-Lisewska, Iwona

    2017-06-23

    Among diverse triggering factors of stress-induced takotsubo cardiomyopathy (TC), a viral or bacterial infection is rarely observed. Sepsis is an exception, regardless of the etiologic pathogen, in which case an excess of catecholamines may result in acute left ventricular dysfunction. TC precipitated by Clostridium difficile infection (CDI) has been reported only in two patients so far. The authors describe another case of TC triggered this time by recurrent C. difficile colitis which occurred in a 72-yearold female. Severe heart failure developed on the second day of a new episode of diarrhea. Echocardiography revealed apical ballooning, a typical form of TC, while the coronary arteries in coronary angiography were normal. Despite proper treatment of CDI, the course of the disease was fatal due to heart failure progression. In considerations of TC pathogenesis in the case presented, the impact of C. difficile toxins should be taken into account. One should remember about the potential extraintestinal complications of CDI, including sudden myocardial depression.

  19. The host immune response to Clostridium difficile infection

    Science.gov (United States)

    2013-01-01

    Clostridium difficile infection (CDI) is the most common infectious cause of healthcare-acquired diarrhoea. Outcomes of C. difficile colonization are varied, from asymptomatic carriage to fulminant colitis and death, due in part to the interplay between the pathogenic virulence factors of the bacterium and the counteractive immune responses of the host. Secreted toxins A and B are the major virulence factors of C. difficile and induce a profound inflammatory response by intoxicating intestinal epithelial cells causing proinflammatory cytokine release. Host cell necrosis, vascular permeability and neutrophil infiltration lead to an elevated white cell count, profuse diarrhoea and in severe cases, dehydration, hypoalbuminaemia and toxic megacolon. Other bacterial virulence factors, including surface layer proteins and flagella proteins, are detected by host cell surface signal molecules that trigger downstream cell-mediated immune pathways. Human studies have identified a role for serum and faecal immunoglobulin levels in protection from disease, but the recent development of a mouse model of CDI has enabled studies into the precise molecular interactions that trigger the immune response during infection. Key effector molecules have been identified that can drive towards a protective anti-inflammatory response or a damaging proinflammatory response. The limitations of current antimicrobial therapies for CDI have led to the development of both active and passive immunotherapies, none of which have, as yet been formally approved for CDI. However, recent advances in our understanding of the molecular basis of host immune protection against CDI may provide an exciting opportunity for novel therapeutic developments in the future. PMID:25165542

  20. Special Concerns for Seniors: Clostridium difficile

    Science.gov (United States)

    ... and Drugs" Home | Contact Us Special Concerns for Seniors Clostridium difficile - an introduction Clostridium difficile (“C. diff”) ... see APUA’s contribution to CDC’s Vital Signs campaign . Seniors are especially at risk People over the age ...

  1. ATM regulates Cdt1 stability during the unperturbed S phase to prevent re-replication

    Science.gov (United States)

    Iwahori, Satoko; Kohmon, Daisuke; Kobayashi, Junya; Tani, Yuhei; Yugawa, Takashi; Komatsu, Kenshi; Kiyono, Tohru; Sugimoto, Nozomi; Fujita, Masatoshi

    2014-01-01

    Ataxia-telangiectasia mutated (ATM) plays crucial roles in DNA damage responses, especially with regard to DNA double-strand breaks (DSBs). However, it appears that ATM can be activated not only by DSB, but also by some changes in chromatin architecture, suggesting potential ATM function in cell cycle control. Here, we found that ATM is involved in timely degradation of Cdt1, a critical replication licensing factor, during the unperturbed S phase. At least in certain cell types, degradation of p27Kip1 was also impaired by ATM inhibition. The novel ATM function for Cdt1 regulation was dependent on its kinase activity and NBS1. Indeed, we found that ATM is moderately phosphorylated at Ser1981 during the S phase. ATM silencing induced partial reduction in levels of Skp2, a component of SCFSkp2 ubiquitin ligase that controls Cdt1 degradation. Furthermore, Skp2 silencing resulted in Cdt1 stabilization like ATM inhibition. In addition, as reported previously, ATM silencing partially prevented Akt phosphorylation at Ser473, indicative of its activation, and Akt inhibition led to modest stabilization of Cdt1. Therefore, the ATM-Akt-SCFSkp2 pathway may partly contribute to the novel ATM function. Finally, ATM inhibition rendered cells hypersensitive to induction of re-replication, indicating importance for maintenance of genome stability. PMID:24280901

  2. Characterization of Clostridium difficile Strains in British Columbia, Canada: A Shift from NAP1 Majority (2008 to Novel Strain Types (2013 in One Region

    Directory of Open Access Journals (Sweden)

    Agatha N. Jassem

    2016-01-01

    Full Text Available Background. Clostridium difficile is a major cause of gastrointestinal illness. Epidemic NAP1 strains contain toxins A and B, a deletion in repressor tcdC, and a binary toxin. Objectives. To determine the molecular epidemiology of C. difficile in British Columbia and compare between two time points in one region. Methods. C. difficile isolates from hospital and community laboratories (2008 and one Island Health hospital laboratory (2013 were characterized by pulsed-field gel electrophoresis, PCR-ribotyping, toxin possession, tcdC genotype, and antimicrobial susceptibility. Results. In 2008, 42.7% of isolates had NAP1 designation. Hospital-collected isolates were associated with older patients and more NAP1 types. Unlike other isolates, most NAP1 isolates possessed binary toxin and a 19 bp loss in tcdC. All isolates were susceptible to metronidazole and vancomycin. A 2013 follow-up revealed a 28.9% decrease in NAP1 isolates and 20.0% increase in isolates without NAP designation in one region. Then, community-associated cases were seen in younger patients, while NAP types were evenly distributed. Isolates without NAP designation did not cluster with a PFGE pattern or ribotype. Conclusions. Evaluation of C. difficile infections within British Columbia revealed demographic associations, epidemiological shifts, and characteristics of strain types. Continuous surveillance of C. difficile will enable detection of emerging strains.

  3. Clinical application of polymerase chain reaction to diagnose Clostridium difficile in hospitalized patients with diarrhea.

    Science.gov (United States)

    Morelli, Michael S; Rouster, Susan D; Giannella, Ralph A; Sherman, Kenneth E

    2004-08-01

    Clostridium difficile is a common cause of diarrhea in hospitalized patients and is associated with significant morbidity and cost. The current diagnostic standard, enzyme immunoassay (EIA), has low sensitivity, leading to duplicate testing and empiric treatment. We sought to show the usefulness and potential cost effectiveness of polymerase chain reaction (PCR) amplification of toxin B gene for diagnosis of C. difficile-induced diarrhea. A total of 148 stool samples from academic and community-based hospitals were sent for EIA testing and were evaluated prospectively for the presence of toxin B gene by PCR. Results were compared with EIA regarding sensitivity, specificity, and predictive values. Medical charts were reviewed to determine the following: (1) number of EIAs sent per admission, (2) number sent within a 24-hour time period, and (3) how caregivers practiced based on EIA results. The mean age of 130 patients was 55 years. EIA and PCR were positive in 6.8% and 13.6% of patients, respectively. EIA sensitivity was 40%, specificity was 98%, and positive and negative predictive values were 80% and 91%, respectively. The cost of the PCR was $22/sample. Empiric treatment for C. difficile was given unnecessarily in 42% of EIA-negative results. Thirty percent of patients had 3 or more EIAs sent during their hospital admission. Of patients with multiple samples sent, 57% had more than 1 sample sent in a 24-hour period. Many physicians do not conform to practice guidelines regarding recommended diagnosis and empiric treatment of C. difficile. Toxin B gene PCR represents a more sensitive and potentially cost-effective method to diagnose C. difficile-induced diarrhea than EIA and should be considered for use as an alternative diagnostic standard.

  4. Clinical manifestations of Clostridium difficile infection in a medical center in Taiwan.

    Science.gov (United States)

    Lai, Chih-Cheng; Lin, Sheng-Hsiang; Tan, Che-Kim; Liao, Chun-Hsing; Huang, Yu-Tsung; Hsueh, Po-Ren

    2014-12-01

    To investigate the clinical characteristics of Clostridium difficile infection (CDI) at a medical center in Taiwan. Patients with CDI were identified from medical records at the National Taiwan University Hospital (Taipei, Taiwan). The following information was gathered and analyzed to better understand the clinical manifestations of CDI: age; sex; underlying immunocompromised conditions; laboratory data; in-hospital mortality; and previous use of drugs such as antimicrobial agents, steroids, and antipeptic ulcer agents. During the years 2000-2010, 122 patients were identified as having CDI. This included 92 patients with nontoxigenic CDI (i.e., positive stool culture for C. difficile but negative results for toxins A and B) and 30 patients with toxigenic CDI (i.e., positive stool culture cultures for C. difficile and positive results for toxins A and B). Of the 122 patients, 48 (39%) patients were older than 65 years and most patients acquired the CDI while in the hospital. Active cancer was the most common reason for hospitalization, followed by diabetes mellitus, and end-stage renal disease. More than 90% of the patients had received antibiotics before acquiring CDI. The results of fecal leukocyte examinations were positive in 33 (27%) patients. The overall in-hospital mortality rate was 26.2%. There were no significant differences between patients with nontoxigenic CDI and patients with toxigenic CDI. Clostridium difficile infection can develop in healthcare facilities and in community settings, especially in immunocompromised patients. Copyright © 2013. Published by Elsevier B.V.

  5. Profiling Humoral Immune Responses to Clostridium difficile-Specific Antigens by Protein Microarray Analysis.

    Science.gov (United States)

    Negm, Ola H; Hamed, Mohamed R; Dilnot, Elizabeth M; Shone, Clifford C; Marszalowska, Izabela; Lynch, Mark; Loscher, Christine E; Edwards, Laura J; Tighe, Patrick J; Wilcox, Mark H; Monaghan, Tanya M

    2015-09-01

    Clostridium difficile is an anaerobic, Gram-positive, and spore-forming bacterium that is the leading worldwide infective cause of hospital-acquired and antibiotic-associated diarrhea. Several studies have reported associations between humoral immunity and the clinical course of C. difficile infection (CDI). Host humoral immune responses are determined using conventional enzyme-linked immunosorbent assay (ELISA) techniques. Herein, we report the first use of a novel protein microarray assay to determine systemic IgG antibody responses against a panel of highly purified C. difficile-specific antigens, including native toxins A and B (TcdA and TcdB, respectively), recombinant fragments of toxins A and B (TxA4 and TxB4, respectively), ribotype-specific surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid and Candida albicans). Microarrays were probed with sera from a total of 327 individuals with CDI, cystic fibrosis without diarrhea, and healthy controls. For all antigens, precision profiles demonstrated ELISA in the quantification of antitoxin A and antitoxin B IgG. These results indicate that microarray is a suitable assay for defining humoral immune responses to C. difficile protein antigens and may have potential advantages in throughput, convenience, and cost. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Microbiota-accessible carbohydrates suppress Clostridium difficile infection in a murine model.

    Science.gov (United States)

    Hryckowian, Andrew J; Van Treuren, William; Smits, Samuel A; Davis, Nicole M; Gardner, Jackson O; Bouley, Donna M; Sonnenburg, Justin L

    2018-04-23

    Clostridium difficile is an opportunistic diarrhoeal pathogen, and C. difficile infection (CDI) represents a major health care concern, causing an estimated 15,000 deaths per year in the United States alone 1 . Several enteric pathogens, including C. difficile, leverage inflammation and the accompanying microbial dysbiosis to thrive in the distal gut 2 . Although diet is among the most powerful available tools for affecting the health of humans and their relationship with their microbiota, investigation into the effects of diet on CDI has been limited. Here, we show in mice that the consumption of microbiota-accessible carbohydrates (MACs) found in dietary plant polysaccharides has a significant effect on CDI. Specifically, using a model of antibiotic-induced CDI that typically resolves within 12 days of infection, we demonstrate that MAC-deficient diets perpetuate CDI. We show that C. difficile burdens are suppressed through the addition of either a diet containing a complex mixture of MACs or a simplified diet containing inulin as the sole MAC source. We show that switches between these dietary conditions are coincident with changes to microbiota membership, its metabolic output and C. difficile-mediated inflammation. Together, our data demonstrate the outgrowth of MAC-utilizing taxa and the associated end products of MAC metabolism, namely, the short-chain fatty acids acetate, propionate and butyrate, are associated with decreased C. difficile fitness despite increased C. difficile toxin expression in the gut. Our findings, when placed into the context of the known fibre deficiencies of a human Western diet, provide rationale for pursuing MAC-centric dietary strategies as an alternate line of investigation for mitigating CDI.

  7. Dynamics and establishment of Clostridium difficile infection in the murine gastrointestinal tract.

    Science.gov (United States)

    Koenigsknecht, Mark J; Theriot, Casey M; Bergin, Ingrid L; Schumacher, Cassie A; Schloss, Patrick D; Young, Vincent B

    2015-03-01

    Clostridium difficile infection (CDI) following antibiotic therapy is a major public health threat. While antibiotic disruption of the indigenous microbiota underlies the majority of cases of CDI, the early dynamics of infection in the disturbed intestinal ecosystem are poorly characterized. This study defines the dynamics of infection with C. difficile strain VPI 10463 throughout the gastrointestinal (GI) tract using a murine model of infection. After inducing susceptibility to C. difficile colonization via antibiotic administration, we followed the dynamics of spore germination, colonization, sporulation, toxin activity, and disease progression throughout the GI tract. C. difficile spores were able to germinate within 6 h postchallenge, resulting in the establishment of vegetative bacteria in the distal GI tract. Spores and cytotoxin activity were detected by 24 h postchallenge, and histopathologic colitis developed by 30 h. Within 36 h, all infected mice succumbed to infection. We correlated the establishment of infection with changes in the microbiota and bile acid profile of the small and large intestines. Antibiotic administration resulted in significant changes to the microbiota in the small and large intestines, as well as a significant shift in the abundance of primary and secondary bile acids. Ex vivo analysis suggested the small intestine as the site of spore germination. This study provides an integrated understanding of the timing and location of the events surrounding C. difficile colonization and identifies potential targets for the development of new therapeutic strategies. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Discovery of LFF571: An Investigational Agent for Clostridium difficile Infection

    Energy Technology Data Exchange (ETDEWEB)

    LaMarche, Matthew J.; Leeds, Jennifer A.; Amaral, Adam; Brewer, Jason T.; Bushell, Simon M.; Deng, Gejing; Dewhurst, Janetta M.; Ding, Jian; Dzink-Fox, JoAnne; Gamber, Gabriel; Jain, Akash; Lee, Kwangho; Lee, Lac; Lister, Troy; McKenney, David; Mullin, Steve; Osborne, Colin; Palestrant, Deborah; Patane, Michael A.; Rann, Elin M.; Sachdeva, Meena; Shao, Jian; Tiamfook, Stacey; Trzasko, Anna; Whitehead, Lewis; Yifru, Aregahegn; Yu, Donghui; Yan, Wanlin; Zhu, Qingming (Novartis)

    2012-11-09

    Clostridium difficile (C. difficile) is a Gram positive, anaerobic bacterium that infects the lumen of the large intestine and produces toxins. This results in a range of syndromes from mild diarrhea to severe toxic megacolon and death. Alarmingly, the prevalence and severity of C. difficile infection are increasing; thus, associated morbidity and mortality rates are rising. 4-Aminothiazolyl analogues of the antibiotic natural product GE2270 A (1) were designed, synthesized, and optimized for the treatment of C. difficile infection. The medicinal chemistry effort focused on enhancing aqueous solubility relative to that of the natural product and previous development candidates (2, 3) and improving antibacterial activity. Structure-activity relationships, cocrystallographic interactions, pharmacokinetics, and efficacy in animal models of infection were characterized. These studies identified a series of dicarboxylic acid derivatives, which enhanced solubility/efficacy profile by several orders of magnitude compared to previously studied compounds and led to the selection of LFF571 (4) as an investigational new drug for treating C. difficile infection.

  9. Cdt1 revisited: complex and tight regulation during the cell cycle and consequences of deregulation in mammalian cells

    Directory of Open Access Journals (Sweden)

    Fujita Masatoshi

    2006-10-01

    Full Text Available Abstract In eukaryotic cells, replication of genomic DNA initiates from multiple replication origins distributed on multiple chromosomes. To ensure that each origin is activated precisely only once during each S phase, a system has evolved which features periodic assembly and disassembly of essential pre-replication complexes (pre-RCs at replication origins. The pre-RC assembly reaction involves the loading of a presumptive replicative helicase, the MCM2-7 complexes, onto chromatin by the origin recognition complex (ORC and two essential factors, CDC6 and Cdt1. The eukaryotic cell cycle is driven by the periodic activation and inactivation of cyclin-dependent kinases (Cdks and assembly of pre-RCs can only occur during the low Cdk activity period from late mitosis through G1 phase, with inappropriate re-assembly suppressed during S, G2, and M phases. It was originally suggested that inhibition of Cdt1 function after S phase in vertebrate cells is due to geminin binding and that Cdt1 hyperfunction resulting from Cdt1-geminin imbalance induces re-replication. However, recent progress has revealed that Cdt1 activity is more strictly regulated by two other mechanisms in addition to geminin: (1 functional and SCFSkp2-mediated proteolytic regulation through phosphorylation by Cdks; and (2 replication-coupled proteolysis mediated by the Cullin4-DDB1Cdt2 ubiquitin ligase and PCNA, an eukaryotic sliding clamp stimulating replicative DNA polymerases. The tight regulation implies that Cdt1 control is especially critical for the regulation of DNA replication in mammalian cells. Indeed, Cdt1 overexpression evokes chromosomal damage even without re-replication. Furthermore, deregulated Cdt1 induces chromosomal instability in normal human cells. Since Cdt1 is overexpressed in cancer cells, this could be a new molecular mechanism leading to carcinogenesis. In this review, recent insights into Cdt1 function and regulation in mammalian cells are discussed.

  10. Antibiotic Susceptibility, Genetic Diversity, and the Presence of Toxin Producing Genes in Campylobacter Isolates from Poultry.

    Science.gov (United States)

    Lee, Jeeyeon; Jeong, Jiyeon; Lee, Heeyoung; Ha, Jimyeong; Kim, Sejeong; Choi, Yukyung; Oh, Hyemin; Seo, Kunho; Yoon, Yohan; Lee, Soomin

    2017-11-17

    This study examined antibiotic susceptibility, genetic diversity, and characteristics of virulence genes in Campylobacter isolates from poultry. Chicken ( n = 152) and duck ( n = 154) samples were collected from 18 wet markets in Korea. Campylobacter spp. isolated from the carcasses were identified by PCR. The isolated colonies were analyzed for antibiotic susceptibility to chloramphenicol, amikacin, erythromycin, tetracycline, ciprofloxacin, nalidixic acid, and enrofloxacin. The isolates were also used to analyze genetic diversity using the DiversiLab TM system and were tested for the presence of cytolethal distending toxin ( cdt ) genes. Campylobacter spp. were isolated from 45 poultry samples out of 306 poultry samples (14.7%) and the average levels of Campylobacter contamination were 22.0 CFU/g and 366.1 CFU/g in chicken and duck samples, respectively. Moreover, more than 90% of the isolates showed resistance to nalidixic acid and ciprofloxacin. Genetic correlation analysis showed greater than 95% similarity between 84.4% of the isolates, and three cdt genes ( cdtA , cdtB , and cdtC ) were present in 71.1% of Campylobacter isolates. These results indicate that Campylobacter contamination should be decreased to prevent and treat Campylobacter foodborne illness.

  11. Screening of bifidobacteria and lactobacilli able to antagonise the cytotoxic effect of Clostridium difficile upon intestinal epithelial HT29 monolayer

    Directory of Open Access Journals (Sweden)

    Lorena eValdés-Varela

    2016-04-01

    Full Text Available Clostridium difficile is an opportunistic pathogen inhabiting the human gut, often being the aetiological agent of infections after a microbiota dysbiosis following, for example, an antibiotic treatment. C. difficile infections (CDI constitute a growing health problem with increasing rates of morbidity and mortality at groups of risk, such as elderly and hospitalized patients, but also in populations traditionally considered low-risk. This could be related to the occurrence of virulent strains which, among other factors, have high-level of resistance to fluoroquinolones, more efficient sporulation and markedly high toxin production. Several novel intervention strategies against CDI are currently under study, such as the use of probiotics to counteract the growth and/or toxigenic activity of C. difficile.In this work, we have analysed the capability of twenty Bifidobacterium and Lactobacillus strains, from human intestinal origin, to counteract the toxic effect of C. difficile LMG21717 upon the human intestinal epithelial cell line HT29. For this purpose, we incubated the bacteria together with toxigenic supernatants obtained from C. difficile. After this co-incubation new supernatants were collected in order to quantify the remnant A and B toxins, as well as to determine their residual toxic effect upon HT29 monolayers. To this end, the real time cell analyser (RTCA model, recently developed in our group to monitor C. difficile toxic effect, was used. Results obtained showed that strains of Bifidobacterium longum and Bifidobacterium breve were able to reduce the toxic effect of the pathogen upon HT29, the RTCA normalized cell-index values being inversely correlated with the amount of remnant toxin in the supernatant. The strain B. longum IPLA20022 showed the highest ability to counteract the cytotoxic effect of C. difficile acting directly against the toxin, also having the highest capability for removing the toxins from the clostridial

  12. Comparison of Control of Clostridium difficile Infection in Six English Hospitals Using Whole-Genome Sequencing.

    Science.gov (United States)

    Eyre, David W; Fawley, Warren N; Rajgopal, Anu; Settle, Christopher; Mortimer, Kalani; Goldenberg, Simon D; Dawson, Susan; Crook, Derrick W; Peto, Tim E A; Walker, A Sarah; Wilcox, Mark H

    2017-08-01

    Variation in Clostridium difficile infection (CDI) rates between healthcare institutions suggests overall incidence could be reduced if the lowest rates could be achieved more widely. We used whole-genome sequencing (WGS) of consecutive C. difficile isolates from 6 English hospitals over 1 year (2013-14) to compare infection control performance. Fecal samples with a positive initial screen for C. difficile were sequenced. Within each hospital, we estimated the proportion of cases plausibly acquired from previous cases. Overall, 851/971 (87.6%) sequenced samples contained toxin genes, and 451 (46.4%) were fecal-toxin-positive. Of 652 potentially toxigenic isolates >90-days after the study started, 128 (20%, 95% confidence interval [CI] 17-23%) were genetically linked (within ≤2 single nucleotide polymorphisms) to a prior patient's isolate from the previous 90 days. Hospital 2 had the fewest linked isolates, 7/105 (7%, 3-13%), hospital 1, 9/70 (13%, 6-23%), and hospitals 3-6 had similar proportions of linked isolates (22-26%) (P ≤ .002 comparing hospital-2 vs 3-6). Results were similar adjusting for locally circulating ribotypes. Adjusting for hospital, ribotype-027 had the highest proportion of linked isolates (57%, 95% CI 29-81%). Fecal-toxin-positive and toxin-negative patients were similarly likely to be a potential transmission donor, OR = 1.01 (0.68-1.49). There was no association between the estimated proportion of linked cases and testing rates. WGS can be used as a novel surveillance tool to identify varying rates of C. difficile transmission between institutions and therefore to allow targeted efforts to reduce CDI incidence. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  13. Detenga las infecciones por C. difficile (Stop C. difficile Infections)

    Centers for Disease Control (CDC) Podcasts

    2012-03-06

    Este podcast se basa en la edición de marzo del 2012 del informe Vital Signs de los CDC. La Clostridium difficile es una bacteria que causa diarrea y está asociada a 14,000 muertes anuales en los Estados Unidos. Este podcast ayuda a los profesionales de la salud a saber cómo prevenir las infecciones por C. difficile.  Created: 3/6/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/6/2012.

  14. Polyamine toxins

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Jensen, Lars S; Vogensen, Stine B

    2005-01-01

    Polyamine toxins, isolated from spiders and wasps, have been used as pharmacological tools for the study of ionotropic receptors, but their use have so far been hampered by their lack of selectivity. In this mini-review, we describe how careful synthetic modification of native polyamine toxins ha...

  15. Mutant analysis of Cdt1's function in suppressing nascent strand elongation during DNA replication in Xenopus egg extracts.

    Science.gov (United States)

    Nakazaki, Yuta; Tsuyama, Takashi; Azuma, Yutaro; Takahashi, Mikiko; Tada, Shusuke

    2017-09-02

    The initiation of DNA replication is strictly regulated by multiple mechanisms to ensure precise duplication of chromosomes. In higher eukaryotes, activity of the Cdt1 protein is temporally regulated during the cell cycle, and deregulation of Cdt1 induces DNA re-replication. In previous studies, we showed that excess Cdt1 inhibits DNA replication by suppressing progression of replication forks in Xenopus egg extracts. Here, we investigated the functional regions of Cdt1 that are required for the inhibition of DNA replication. We constructed a series of N-terminally or C-terminally deleted mutants of Cdt1 and examined their inhibitory effects on DNA replication in Xenopus egg extracts. Our results showed that the region spanning amino acids (a. a.) 255-620 is required for efficient inhibition of DNA replication, and that, within this region, a. a. 255-289 have a critical role in inhibition. Moreover, one of the Cdt1 mutants, Cdt1 R285A, was compromised with respect to the licensing activity but still inhibited DNA replication. This result suggests that Cdt1 has an unforeseen function in the negative regulation of DNA replication, and that this function is located within a molecular region that is distinct from those required for the licensing activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. PyCDT: A Python toolkit for modeling point defects in semiconductors and insulators

    Science.gov (United States)

    Broberg, Danny; Medasani, Bharat; Zimmermann, Nils E. R.; Yu, Guodong; Canning, Andrew; Haranczyk, Maciej; Asta, Mark; Hautier, Geoffroy

    2018-05-01

    Point defects have a strong impact on the performance of semiconductor and insulator materials used in technological applications, spanning microelectronics to energy conversion and storage. The nature of the dominant defect types, how they vary with processing conditions, and their impact on materials properties are central aspects that determine the performance of a material in a certain application. This information is, however, difficult to access directly from experimental measurements. Consequently, computational methods, based on electronic density functional theory (DFT), have found widespread use in the calculation of point-defect properties. Here we have developed the Python Charged Defect Toolkit (PyCDT) to expedite the setup and post-processing of defect calculations with widely used DFT software. PyCDT has a user-friendly command-line interface and provides a direct interface with the Materials Project database. This allows for setting up many charged defect calculations for any material of interest, as well as post-processing and applying state-of-the-art electrostatic correction terms. Our paper serves as a documentation for PyCDT, and demonstrates its use in an application to the well-studied GaAs compound semiconductor. We anticipate that the PyCDT code will be useful as a framework for undertaking readily reproducible calculations of charged point-defect properties, and that it will provide a foundation for automated, high-throughput calculations.

  17. Premarket evaluations of the IMDx C. difficile for Abbott m2000 Assay and the BD Max Cdiff Assay.

    Science.gov (United States)

    Stellrecht, K A; Espino, A A; Maceira, V P; Nattanmai, S M; Butt, S A; Wroblewski, D; Hannett, G E; Musser, K A

    2014-05-01

    Clostridium difficile-associated diarrhea is a well-recognized complication of antibiotic use. Historically, diagnosing C. difficile has been difficult, as antigen assays are insensitive and culture-based methods require several days to yield results. Nucleic acid amplification tests (NAATs) are quickly becoming the standard of care. We compared the performance of two automated investigational/research use only (IUO/RUO) NAATs for the detection of C. difficile toxin genes, the IMDx C. difficile for Abbott m2000 Assay (IMDx) and the BD Max Cdiff Assay (Max). A prospective analysis of 111 stool specimens received in the laboratory for C. difficile testing by the laboratory's test of record (TOR), the BD GeneOhm Cdiff Assay, and a retrospective analysis of 88 specimens previously determined to be positive for C. difficile were included in the study. One prospective specimen was excluded due to loss to follow-up discrepancy analysis. Of the remaining 198 specimens, 90 were positive by all three methods, 9 were positive by TOR and Max, and 3 were positive by TOR only. One negative specimen was initially inhibitory by Max. The remaining 95 specimens were negative by all methods. Toxigenic C. difficile culture was performed on the 12 discrepant samples. True C. difficile-positive status was defined as either positive by all three amplification assays or positive by toxigenic culture. Based on this definition, the sensitivity and specificity were 96.9% and 95% for Max and 92.8% and 100% for IMDx. In summary, both highly automated systems demonstrated excellent performance, and each has individual benefits, which will ensure that they will both have a niche in clinical laboratories.

  18. The Conserved Spore Coat Protein SpoVM Is Largely Dispensable in Clostridium difficile Spore Formation.

    Science.gov (United States)

    Ribis, John W; Ravichandran, Priyanka; Putnam, Emily E; Pishdadian, Keyan; Shen, Aimee

    2017-01-01

    transform into vegetative, toxin-secreting cells. During infection, C. difficile must also induce spore formation to survive exit from the host. Since spore formation is essential for transmission, understanding the basic mechanisms underlying sporulation in C. difficile could inform the development of therapeutic strategies targeting spores. In this study, we determine the requirement of the C. difficile homolog of SpoVM, a protein that is essential for spore formation in Bacillus subtilis due to its regulation of coat and cortex formation. We observed that SpoVM plays a minor role in C. difficile spore formation, in contrast with B. subtilis , indicating that this protein would not be a good target for inhibiting spore formation.

  19. Clostridium difficile Infection in Outpatients

    Centers for Disease Control (CDC) Podcasts

    2011-11-07

    Dr. Jon Mark Hirshon, Associate Professor of Emergency Medicine at the University of Maryland School of Medicine, discusses Clostridium difficile infection in outpatients.  Created: 11/7/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/21/2011.

  20. Clostridium difficile in Retail Meats

    Centers for Disease Control (CDC) Podcasts

    Clostridium difficile is a common cause of diarrhea in healthcare settings but little is known about what causes cases in the community. In this podcast, CDC's Dr. L. Clifford McDonald discusses two papers in the May 2009 edition of Emerging Infectious Diseases that explore whether the organism could be found in meat samples purchased in grocery stores in Arizona and Canada.

  1. Treatment of Clostridium difficile infection in mice with vancomycin alone is as effective as treatment with vancomycin and metronidazole in combination

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Aarup, Mie; Hagemann-Madsen, Rikke

    2015-01-01

    OBJECTIVE: Clostridium difficile is a major cause of nosocomial infectious diarrhoea. Treatment of C. difficile infection (CDI) depends on disease severity. A combination of vancomycin and metronidazole is often recommended in severe cases. The aim of this study was to examine, in a murine model....... difficile toxins. RESULTS: None of the mice in the vancomycin-treated group died during the treatment phase compared to a mortality of 17%, 33% and 55% in the combination, metronidazole and infected control group, respectively. Mice treated with vancomycin alone or in combination with metronidazole...... of CDI, if mice treated with a combination of vancomycin and metronidazole had a better clinical outcome than mice treated with vancomycin or metronidazole alone. DESIGN: C57BL/6J mice pretreated with an antimicrobial mixture were challenged with C. difficile VPI 10463 or phosphate-buffered saline...

  2. Clostridium difficile Testing Algorithm: Is There a Difference in Patients Who Test Positive by Enzyme Immunoassay vs. Those Who Only Test Positive by Nucleic Acid Amplification Methodology?

    OpenAIRE

    Polak, Jonathan; Odili, Ogheneruona; Craver, Mary Ashleigh; Mayen, Anthony; Purrman, Kyle; Rahman, Asem; Sang, Charlie Joseph; Cook, Paul P

    2017-01-01

    Abstract Background Testing for Clostridium difficile infection (CDI) commonly involves checking for the presence of toxins A and B by enzyme immunoassay (EIA) or nucleic acid amplification (NAA). The former is very specific, but not very sensitive. The latter is very sensitive. Beginning in 2011, our hospital incorporated an algorithm that involved testing liquid stool specimens for glutamate dehydrogenase (GDH) and toxin by EIA. For discrepant results, the stool specimen was tested for the ...

  3. The Phosphotransfer Protein CD1492 Represses Sporulation Initiation in Clostridium difficile.

    Science.gov (United States)

    Childress, Kevin O; Edwards, Adrianne N; Nawrocki, Kathryn L; Anderson, Sarah E; Woods, Emily C; McBride, Shonna M

    2016-12-01

    The formation of spores is critical for the survival of Clostridium difficile outside the host gastrointestinal tract. Persistence of C. difficile spores greatly contributes to the spread of C. difficile infection (CDI), and the resistance of spores to antimicrobials facilitates the relapse of infection. Despite the importance of sporulation to C. difficile pathogenesis, the molecular mechanisms controlling spore formation are not well understood. The initiation of sporulation is known to be regulated through activation of the conserved transcription factor Spo0A. Multiple regulators influence Spo0A activation in other species; however, many of these factors are not conserved in C. difficile and few novel factors have been identified. Here, we investigated the function of a protein, CD1492, that is annotated as a kinase and was originally proposed to promote sporulation by directly phosphorylating Spo0A. We found that deletion of CD1492 resulted in increased sporulation, indicating that CD1492 is a negative regulator of sporulation. Accordingly, we observed increased transcription of Spo0A-dependent genes in the CD1492 mutant. Deletion of CD1492 also resulted in decreased toxin production in vitro and in decreased virulence in the hamster model of CDI. Further, the CD1492 mutant demonstrated effects on gene expression that are not associated with Spo0A activation, including lower sigD and rstA transcription, suggesting that this protein interacts with factors other than Spo0A. Altogether, the data indicate that CD1492 negatively affects sporulation and positively influences motility and virulence. These results provide further evidence that C. difficile sporulation is regulated differently from that of other endospore-forming species. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. Identification of a Novel Lipoprotein Regulator of Clostridium difficile Spore Germination.

    Directory of Open Access Journals (Sweden)

    Kelly A Fimlaid

    2015-10-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming pathogen and a leading cause of nosocomial diarrhea. C. difficile infections are transmitted when ingested spores germinate in the gastrointestinal tract and transform into vegetative cells. Germination begins when the germinant receptor CspC detects bile salts in the gut. CspC is a subtilisin-like serine pseudoprotease that activates the related CspB serine protease through an unknown mechanism. Activated CspB cleaves the pro-SleC zymogen, which allows the activated SleC cortex hydrolase to degrade the protective cortex layer. While these regulators are essential for C. difficile spores to outgrow and form toxin-secreting vegetative cells, the mechanisms controlling their function have only been partially characterized. In this study, we identify the lipoprotein GerS as a novel regulator of C. difficile spore germination using targeted mutagenesis. A gerS mutant has a severe germination defect and fails to degrade cortex even though it processes SleC at wildtype levels. Using complementation analyses, we demonstrate that GerS secretion, but not lipidation, is necessary for GerS to activate SleC. Importantly, loss of GerS attenuates the virulence of C. difficile in a hamster model of infection. Since GerS appears to be conserved exclusively in related Peptostreptococcaeace family members, our results contribute to a growing body of work indicating that C. difficile has evolved distinct mechanisms for controlling the exit from dormancy relative to B. subtilis and other spore-forming organisms.

  5. Comparison of Simplexa universal direct PCR with cytotoxicity assay for diagnosis of Clostridium difficile infection: performance, cost, and correlation with disease.

    Science.gov (United States)

    Landry, Marie L; Ferguson, David; Topal, Jeffrey

    2014-01-01

    Simplexa Clostridium difficile universal direct PCR, a real-time PCR assay for the detection of the C. difficile toxin B (tcdB) gene using the 3M integrated cycler, was compared with a two-step algorithm which includes the C. Diff Chek-60 glutamate dehydrogenase (GDH) antigen assay followed by cytotoxin neutralization. Three hundred forty-two liquid or semisolid stools submitted for diagnostic C. difficile testing, 171 GDH antigen positive and 171 GDH antigen negative, were selected for the study. All samples were tested by the C. Diff Chek-60 GDH antigen assay, cytotoxin neutralization, and Simplexa direct PCR. Of 171 GDH-positive samples, 4 were excluded (from patients on therapy or from whom duplicate samples were obtained) and 88 were determined to be true positives for toxigenic C. difficile. Of the 88, 67 (76.1%) were positive by the two-step method and 86 (97.7%) were positive by PCR. Seventy-nine were positive by the GDH antigen assay only. Of 171 GDH antigen-negative samples, none were positive by PCR. One antigen-negative sample positive by the cytotoxin assay only was deemed a false positive based on chart review. Simplexa C. difficile universal direct PCR was significantly more sensitive for detecting toxigenic C. difficile bacteria than cytotoxin neutralization (P = 0.0002). However, most PCR-positive/cytotoxin-negative patients did not have clear C. difficile disease. The estimated cost avoidance provided by a more rapid molecular diagnosis was outweighed by the cost of isolating and treating PCR-positive/cytotoxin-negative patients. The costs, clinical consequences, and impact on nosocomial transmission of treating and/or isolating patients positive for toxigenic C. difficile by PCR but negative for in vivo toxin production merit further study.

  6. Models for the study of Clostridium difficile infection

    Science.gov (United States)

    Best, Emma L.; Freeman, Jane; Wilcox, Mark H.

    2012-01-01

    Models of Clostridium difficile infection (C. difficile) have been used extensively for Clostridium difficile (C. difficile) research. The hamster model of C. difficile infection has been most extensively employed for the study of C. difficile and this has been used in many different areas of research, including the induction of C. difficile, the testing of new treatments, population dynamics and characterization of virulence. Investigations using in vitro models for C. difficile introduced the concept of colonization resistance, evaluated the role of antibiotics in C. difficile development, explored population dynamics and have been useful in the evaluation of C. difficile treatments. Experiments using models have major advantages over clinical studies and have been indispensible in furthering C. difficile research. It is important for future study programs to carefully consider the approach to use and therefore be better placed to inform the design and interpretation of clinical studies. PMID:22555466

  7. Botulinum toxin

    Directory of Open Access Journals (Sweden)

    Nigam P

    2010-01-01

    Full Text Available Botulinum toxin, one of the most poisonous biological substances known, is a neurotoxin produced by the bacterium Clostridium botulinum. C. botulinum elaborates eight antigenically distinguishable exotoxins (A, B, C 1 , C 2 , D, E, F and G. All serotypes interfere with neural transmission by blocking the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. The weakness induced by injection with botulinum toxin A usually lasts about three months. Botulinum toxins now play a very significant role in the management of a wide variety of medical conditions, especially strabismus and focal dystonias, hemifacial spasm, and various spastic movement disorders, headaches, hypersalivation, hyperhidrosis, and some chronic conditions that respond only partially to medical treatment. The list of possible new indications is rapidly expanding. The cosmetological applications include correction of lines, creases and wrinkling all over the face, chin, neck, and chest to dermatological applications such as hyperhidrosis. Injections with botulinum toxin are generally well tolerated and side effects are few. A precise knowledge and understanding of the functional anatomy of the mimetic muscles is absolutely necessary to correctly use botulinum toxins in clinical practice.

  8. Clostridium difficile infection in the elderly: an update on management

    Directory of Open Access Journals (Sweden)

    Asempa TE

    2017-10-01

    Full Text Available Tomefa E Asempa, David P Nicolau Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA Abstract: The burden of Clostridium difficile infection (CDI is profound and growing. CDI now represents a common cause of health care–associated diarrhea, and is associated with significant morbidity, mortality, and health care costs. CDI disproportionally affects the elderly, possibly explained by the following risk factors: age-related impairment of the immune system, increasing antibiotic utilization, and frequent health care exposure. In the USA, recent epidemiological studies estimate that two out of every three health care–associated CDIs occur in patients 65 years or older. Additionally, the elderly are at higher risk for recurrent CDI. Existing therapeutic options include metronidazole, oral vancomycin, and fidaxomicin. Choice of agent depends on disease severity, history of recurrence, and, increasingly, the drug cost. Bezlotoxumab, a recently approved monoclonal antibody targeting C. difficile toxin B, offers an exciting advancement into immunologic therapies. Similarly, fecal microbiota transplantation is gaining popularity as an effective option mainly for recurrent CDI. The challenge of decreasing CDI burden in the elderly involves adopting preventative strategies, optimizing initial treatment, and decreasing the risk of recurrence. Expanded strategies are certainly needed to improve outcomes in this high-risk population. This review considers available data from prospective and retrospective studies as well as case reports to illustrate the merits and gaps in care related to the management of CDI in the elderly. Keywords: Clostridium difficile, recurrence, risk factors, elderly, aging, treatment, bezlotoxumab, fecal microbiota transplant

  9. Isolation of recombinant antibodies directed against surface proteins of Clostridium difficile.

    Science.gov (United States)

    Shirvan, Ali Nazari; Aitken, Robert

    2016-01-01

    Clostridium difficile has emerged as an increasingly important nosocomial pathogen and the prime causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. In addition to toxins A and B, immunological studies using antisera from patients infected with C. difficile have shown that a number of other bacterial factors contribute to the pathogenesis, including surface proteins, which are responsible for adhesion, motility and other interactions with the human host. In this study, various clostridial targets, including FliC, FliD and cell wall protein 66, were expressed and purified. Phage antibody display yielded a large panel of specific recombinant antibodies, which were expressed, purified and characterised. Reactions of the recombinant antibodies with their targets were detected by enzyme-linked immunosorbent assay; and Western blotting suggested that linear rather than conformational epitopes were recognised. Binding of the recombinant antibodies to surface-layer proteins and their components showed strain specificity, with good recognition of proteins from C. difficile 630. However, no reaction was observed for strain R20291-a representative of the 027 ribotype. Binding of the recombinant antibodies to C. difficile M120 extracts indicated that a component of a surface-layer protein of this strain might possess immunoglobulin-binding activities. The recombinant antibodies against FliC and FliD proteins were able to inhibit bacterial motility. Copyright © 2016. Published by Elsevier Editora Ltda.

  10. Succession in the gut microbiome following antibiotic and antibody therapies for Clostridium difficile.

    Science.gov (United States)

    Peterfreund, Gregory L; Vandivier, Lee E; Sinha, Rohini; Marozsan, Andre J; Olson, William C; Zhu, Jun; Bushman, Frederic D

    2012-01-01

    Antibiotic disruption of the intestinal microbiota may cause susceptibility to pathogens that is resolved by progressive bacterial outgrowth and colonization. Succession is central to ecological theory but not widely documented in studies of the vertebrate microbiome. Here, we study succession in the hamster gut after treatment with antibiotics and exposure to Clostridium difficile. C. difficile infection is typically lethal in hamsters, but protection can be conferred with neutralizing antibodies against the A and B toxins. We compare treatment with neutralizing monoclonal antibodies (mAb) to treatment with vancomycin, which prolongs the lives of animals but ultimately fails to protect them from death. We carried out longitudinal deep sequencing analysis and found distinctive waves of succession associated with each form of treatment. Clindamycin sensitization prior to infection was associated with the temporary suppression of the previously dominant Bacteroidales and the fungus Saccinobaculus in favor of Proteobacteria. In mAb-treated animals, C. difficile proliferated before joining Proteobacteria in giving way to re-expanding Bacteroidales and the fungus Wickerhamomyces. However, the Bacteroidales lineages returning by day 7 were different from those that were present initially, and they persisted for the duration of the experiment. Animals treated with vancomycin showed a different set of late-stage lineages that were dominated by Proteobacteria as well as increased disparity between the tissue-associated and luminal cecal communities. The control animals showed no change in their gut microbiota. These data thus suggest different patterns of ecological succession following antibiotic treatment and C. difficile infection.

  11. Succession in the gut microbiome following antibiotic and antibody therapies for Clostridium difficile.

    Directory of Open Access Journals (Sweden)

    Gregory L Peterfreund

    Full Text Available Antibiotic disruption of the intestinal microbiota may cause susceptibility to pathogens that is resolved by progressive bacterial outgrowth and colonization. Succession is central to ecological theory but not widely documented in studies of the vertebrate microbiome. Here, we study succession in the hamster gut after treatment with antibiotics and exposure to Clostridium difficile. C. difficile infection is typically lethal in hamsters, but protection can be conferred with neutralizing antibodies against the A and B toxins. We compare treatment with neutralizing monoclonal antibodies (mAb to treatment with vancomycin, which prolongs the lives of animals but ultimately fails to protect them from death. We carried out longitudinal deep sequencing analysis and found distinctive waves of succession associated with each form of treatment. Clindamycin sensitization prior to infection was associated with the temporary suppression of the previously dominant Bacteroidales and the fungus Saccinobaculus in favor of Proteobacteria. In mAb-treated animals, C. difficile proliferated before joining Proteobacteria in giving way to re-expanding Bacteroidales and the fungus Wickerhamomyces. However, the Bacteroidales lineages returning by day 7 were different from those that were present initially, and they persisted for the duration of the experiment. Animals treated with vancomycin showed a different set of late-stage lineages that were dominated by Proteobacteria as well as increased disparity between the tissue-associated and luminal cecal communities. The control animals showed no change in their gut microbiota. These data thus suggest different patterns of ecological succession following antibiotic treatment and C. difficile infection.

  12. Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

    Directory of Open Access Journals (Sweden)

    Edmir Geraldo Fraga

    2016-09-01

    Full Text Available Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

  13. Community-acquired Clostridium difficile infection in children: A retrospective study.

    Science.gov (United States)

    Borali, Elena; Ortisi, Giuseppe; Moretti, Chiara; Stacul, Elisabetta Francesca; Lipreri, Rita; Gesu, Giovanni Pietro; De Giacomo, Costantino

    2015-10-01

    Community acquired-Clostridium difficile infection (CDI) has increased also in children in the last years. To determine the incidence of community-acquired CDI and to understand whether Clostridium difficile could be considered a symptom-triggering pathogen in infants. A five-year retrospective analysis (January 2007-December 2011) of faecal specimens from 124 children hospitalized in the Niguarda Ca' Granda Hospital for prolonged or muco-haemorrhagic diarrhoea was carried out. Stool samples were evaluated for common infective causes of diarrhoea and for Clostridium difficile toxins. Patients with and without CDI were compared for clinical characteristics and known risk factors for infection. Twenty-two children with CDI were identified in 5 years. An increased incidence of community-acquired CDI was observed, ranging from 0.75 per 1000 hospitalizations in 2007 to 9.8 per 1000 hospitalizations in 2011. Antimicrobial treatment was successful in all 19 children in whom it was administered; 8/22 CDI-positive children were younger than 2 years. No statistically significant differences in clinical presentation were observed between patients with and without CDI, nor in patients with and without risk factors for CDI. Our study shows that Clostridium difficile infection is increasing and suggests a possible pathogenic role in the first 2 years of life. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  14. [Identifying gaps between guidelines and clinical practice in Clostridium difficile infection].

    Science.gov (United States)

    Rodríguez-Martín, C; Serrano-Morte, A; Sánchez-Muñoz, L A; de Santos-Castro, P A; Bratos-Pérez, M A; Ortiz de Lejarazu-Leonardo, R

    2016-01-01

    The first aim was to determine whether patients are being treated in accordance with the Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America (IDSA/SHEA) Clostridium difficile guidelines and whether adherence impacts patient outcomes. The second aim was to identify specific action items in the guidelines that are not being translated into clinical practice, for their subsequent implementation. A retrospective, descriptive study was conducted over a 36 month period, on patients with compatible clinical symptoms and positive test for C. difficile toxins A and/or B in stool samples, in an internal medicine department of a tertiary medical centre. Patient demographic and clinical data (outcomes, comorbidity, risk factors) and compliance with guidelines, were examined A total of 77 patients with C. difficile infection were identified (87 episodes). Stratified by disease severity criteria, 49.3% of patients were mild-moderate, 35.1% severe, and 15.6% severe-complicated. Full adherence with the guidelines was observed in only 40.2% of patients, and was significantly better for mild-moderate (71.0%), than in severe (7.4%) or severe-complicated patients (16.6%) (PClostridium difficile infection was poor, especially in severe and severe-complicated patients, being associated with worse clinical outcomes. Educational interventions aimed at improving guideline adherence are warranted. Copyright © 2015 SECA. Published by Elsevier Espana. All rights reserved.

  15. Probiotics in Clostridium difficile infection: reviewing the need for a multistrain probiotic.

    Science.gov (United States)

    Hell, M; Bernhofer, C; Stalzer, P; Kern, J M; Claassen, E

    2013-03-01

    In the past two years an enormous amount of molecular, genetic, metabolomic and mechanistic data on the host-bacterium interaction, a healthy gut microbiota and a possible role for probiotics in Clostridium difficile infection (CDI) has been accumulated. Also, new hypervirulent strains of C. difficile have emerged. Yet, clinical trials in CDI have been less promising than in antibiotic associated diarrhoea in general, with more meta-analysis than primary papers on CDI-clinical-trials. The fact that C. difficile is a spore former, producing at least three different toxins has not yet been incorporated in the rational design of probiotics for (recurrent) CDI. Here we postulate that the plethora of effects of C. difficile and the vast amount of data on the role of commensal gut residents and probiotics point towards a multistrain mixture of probiotics to reduce CDI, but also to limit (nosocomial) transmission and/or endogenous reinfection. On the basis of a retrospective chart review of a series of ten CDI patients where recurrence was expected, all patients on adjunctive probiotic therapy with multistrain cocktail (Ecologic®AAD/OMNiBiOTiC® 10) showed complete clinical resolution. This result, and recent success in faecal transplants in CDI treatment, are supportive for the rational design of multistrain probiotics for CDI.

  16. Bezlotoxumab: A Review in Preventing Clostridium difficile Infection Recurrence.

    Science.gov (United States)

    Deeks, Emma D

    2017-10-01

    Bezlotoxumab (Zinplava™) is a fully human monoclonal antibody against Clostridium difficile toxin B indicated for the prevention of C. difficile infection (CDI) recurrence in patients with a high recurrence risk. It is the first agent approved for recurrence prevention and is administered as a single intravenous infusion in conjunction with standard-of-care (SoC) antibacterial treatment for CDI. In well-designed, placebo-controlled, phase 3 trials (MODIFY 1 and 2), a single infusion of bezlotoxumab, given in combination with SoC antibacterial therapy for CDI in adults, was effective in reducing CDI recurrence in the 12 weeks post-treatment, with this benefit being seen mainly in the patients at high recurrence risk. Bezlotoxumab did not impact the efficacy of the antibacterials being used to treat the CDI and, consistent with its benefits on CDI recurrence, appeared to reduce the need for subsequent antibacterials, thus minimizing further gut microbiota disruption. Longer term, there were no further CDI recurrences over 12 months' follow-up among patients who had received bezlotoxumab in MODIFY 2 and entered an extension substudy. Bezlotoxumab has low immunogenicity and is generally well tolerated, although the potential for heart failure in some patients requires consideration; cost-effectiveness data for bezlotoxumab are awaited with interest. Thus, a single intravenous infusion of bezlotoxumab during SoC antibacterial treatment for CDI is an emerging option for reducing CDI recurrence in adults at high risk of recurrence.

  17. Clostridium difficile infection in the elderly: an update on management.

    Science.gov (United States)

    Asempa, Tomefa E; Nicolau, David P

    2017-01-01

    The burden of Clostridium difficile infection (CDI) is profound and growing. CDI now represents a common cause of health care-associated diarrhea, and is associated with significant morbidity, mortality, and health care costs. CDI disproportionally affects the elderly, possibly explained by the following risk factors: age-related impairment of the immune system, increasing antibiotic utilization, and frequent health care exposure. In the USA, recent epidemiological studies estimate that two out of every three health care-associated CDIs occur in patients 65 years or older. Additionally, the elderly are at higher risk for recurrent CDI. Existing therapeutic options include metronidazole, oral vancomycin, and fidaxomicin. Choice of agent depends on disease severity, history of recurrence, and, increasingly, the drug cost. Bezlotoxumab, a recently approved monoclonal antibody targeting C. difficile toxin B, offers an exciting advancement into immunologic therapies. Similarly, fecal microbiota transplantation is gaining popularity as an effective option mainly for recurrent CDI. The challenge of decreasing CDI burden in the elderly involves adopting preventative strategies, optimizing initial treatment, and decreasing the risk of recurrence. Expanded strategies are certainly needed to improve outcomes in this high-risk population. This review considers available data from prospective and retrospective studies as well as case reports to illustrate the merits and gaps in care related to the management of CDI in the elderly.

  18. Clostridium difficile infection in Thailand.

    Science.gov (United States)

    Putsathit, Papanin; Kiratisin, Pattarachai; Ngamwongsatit, Puriya; Riley, Thomas V

    2015-01-01

    Clostridium difficile is the aetiological agent in ca. 20% of cases of antimicrobial-associated diarrhoea in hospitalised adults. Diseases caused by this organism range from mild diarrhoea to occasional fatal pseudomembranous colitis. The epidemiology of C. difficile infection (CDI) has changed notably in the past decade, following epidemics in the early 2000s of PCR ribotype (RT) 027 infection in North America and Europe, where there was an increase in disease severity and mortality. Another major event has been the emergence of RT 078, initially as the predominant ribotype in production animals in the USA and Europe, and then in humans in Europe. Although there have been numerous investigations of the epidemiology of CDI in North America and Europe, limited studies have been undertaken elsewhere, particularly in Asia. Antimicrobial exposure remains the major risk factor for CDI. Given the high prevalence of indiscriminate and inappropriate use of antimicrobials in Asia, it is conceivable that CDI is relatively common among humans and animals. This review describes the level of knowledge in Thailand regarding C. difficile detection methods, prevalence and antimicrobial susceptibility profile, as well as the clinical features of, treatment options for and outcomes of the disease. In addition, antimicrobial usage in livestock in Thailand will be reviewed. A literature search yielded 18 studies mentioning C. difficile in Thailand, a greater number than from any other Asian country. It is possible that the situation in Thailand in relation to CDI may mirror the situation in other developing Asians countries. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  19. Diversity of Clostridium difficile PCR ribotypes in Europe: results from the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), 2012 and 2013.

    Science.gov (United States)

    Davies, Kerrie A; Ashwin, Helen; Longshaw, Christopher M; Burns, David A; Davis, Georgina L; Wilcox, Mark H

    2016-07-21

    Clostridium difficile infection (CDI) is the major cause of infective diarrhoea in healthcare environments. As part of the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), the largest C. difficile epidemiological study of its type, PCR ribotype distribution of C. difficile isolates in Europe was investigated. PCR ribotyping was performed on 1,196 C. difficile isolates from diarrhoeal samples sent to the European coordinating laboratory in 2012-13 and 2013 (from two sampling days) by 482 participating hospitals from 19 European countries. A total of 125 ribotypes were identified, of which ribotypes 027 (19%, n =222), 001/072 (11%, n = 134) and 014/020 (10%, n = 119) were the most prevalent. Distinct regional patterns of ribotype distribution were noted. Of 596 isolates from patients with toxin-positive stools (CDI cases), ribotype 027 accounted for 22% (32/144) of infections in cases aged from 18 to less than 65 years, but the prevalence decreased in those aged ≥ 65 years (14% (59/412)) and further decreased in those aged ≥ 81 years (9% (18/195)). The prevalence of ribotype 027 and 176, but not other epidemic strains, was inversely proportional to overall ribotype diversity (R(2) = 0.717). This study highlights an increased diversity of C. difficile ribotypes across Europe compared with previous studies, with considerable intercountry variation in ribotype distribution. Continuous surveillance programmes are necessary to monitor the changing epidemiology of C. difficile. This article is copyright of The Authors, 2016.

  20. Update on Clostridium difficile infections.

    Science.gov (United States)

    Le Monnier, A; Zahar, J-R; Barbut, F

    2014-08-01

    Clostridium difficile infections (CDI) occur primarily in hospitalized patients with risk factors such as concomitant or recent use of antibiotics. CDI related additional costs are important for the global population and health-care facilities. CDI epidemiology has changed since 2003: they became more frequent boosted by large outbreaks, more severe, more resistant to antibiotic treatment, and spread to new groups of population without any risk factor. This is partly due to the emergence and worldwide dissemination of new and more virulent C. difficile strains such as the epidemic clone 027/NAP1/BI. The host immune response plays a central role in the pathogenesis of CDI and could also be involved in the occurrence of recurrent or severe forms. New guidelines including new molecular tests (NAAT) have recently clarified and simplified the diagnostic strategies for the microbiological diagnosis of CDI. The CDI incidence was proven to be related to the level of clinical suspicion and the frequency of microbiological screening for C. difficile. The current recommendations for the treatment of CDI mention oral metronidazole as the first line treatment for mild to moderate diarrhea. Oral vancomycin use should be restricted to severe cases. In the absence of consensus, the treatment of multiple recurrences remains a major concern. New and more targeted antibiotics and innovative therapeutic strategies (fecal transplantation, monoclonal antibodies, and vaccination) have emerged as new therapies for CDI. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  1. Low frequency of asymptomatic carriage of toxigenic Clostridium difficile in an acute care geriatric hospital: prospective cohort study in Switzerland

    Directory of Open Access Journals (Sweden)

    Daniela Pires

    2016-06-01

    Full Text Available Abstract Background The role of asymptomatic carriers of toxigenic Clostridium difficile (TCD in nosocomial cross-transmission remains debatable. Moreover, its relevance in the elderly has been sparsely studied. Objectives To assess asymptomatic TCD carriage in an acute care geriatric population. Methods We performed a prospective cohort study at the 296-bed geriatric hospital of the Geneva University Hospitals. We consecutively recruited all patients admitted to two 15-bed acute-care wards. Patients with C. difficile infection (CDI or diarrhoea at admission were excluded. First bowel movement after admission and every two weeks thereafter were sampled. C. difficile toxin B gene was identified using real-time polymerase chain-reaction (BD MAXTMCdiff. Asymptomatic TCD carriage was defined by the presence of the C. difficile toxin B gene without diarrhoea. Results A total of 102 patients were admitted between March and June 2015. Two patients were excluded. Among the 100 patients included in the study, 63 were hospitalized and 1 had CDI in the previous year, and 36 were exposed to systemic antibiotics within 90 days prior to admission. Overall, 199 stool samples were collected (median 2 per patient, IQR 1-3. Asymptomatic TCD carriage was identified in two patients (2 %. Conclusions We found a low prevalence of asymptomatic TCD carriage in a geriatric population frequently exposed to antibiotics and healthcare. Our findings suggest that asymptomatic TCD carriage might contribute only marginally to nosocomial TCD cross-transmission in our and similar healthcare settings.

  2. Characterization of conserved arginine residues on Cdt1 that affect licensing activity and interaction with Geminin or Mcm complex.

    Science.gov (United States)

    You, Zhiying; Ode, Koji L; Shindo, Mayumi; Takisawa, Haruhiko; Masai, Hisao

    2016-05-02

    All organisms ensure once and only once replication during S phase through a process called replication licensing. Cdt1 is a key component and crucial loading factor of Mcm complex, which is a central component for the eukaryotic replicative helicase. In higher eukaryotes, timely inhibition of Cdt1 by Geminin is essential to prevent rereplication. Here, we address the mechanism of DNA licensing using purified Cdt1, Mcm and Geminin proteins in combination with replication in Xenopus egg extracts. We mutagenized the 223th arginine of mouse Cdt1 (mCdt1) to cysteine or serine (R-S or R-C, respectively) and 342nd and 346th arginines constituting an arginine finger-like structure to alanine (RR-AA). The RR-AA mutant of Cdt1 could not only rescue the DNA replication activity in Cdt1-depleted extracts but also its specific activity for DNA replication and licensing was significantly increased compared to the wild-type protein. In contrast, the R223 mutants were partially defective in rescue of DNA replication and licensing. Biochemical analyses of these mutant Cdt1 proteins indicated that the RR-AA mutation disabled its functional interaction with Geminin, while R223 mutations resulted in ablation in interaction with the Mcm2∼7 complex. Intriguingly, the R223 mutants are more susceptible to the phosphorylation-induced inactivation or chromatin dissociation. Our results show that conserved arginine residues play critical roles in interaction with Geminin and Mcm that are crucial for proper conformation of the complexes and its licensing activity.

  3. Evaluation of the BD Max Cdiff assay for the detection of toxigenic Clostridium difficile in human stool specimens.

    Science.gov (United States)

    Putsathit, Papanin; Morgan, Justin; Bradford, Damien; Engelhardt, Nelly; Riley, Thomas V

    2015-02-01

    The Becton Dickinson (BD) PCR-based GeneOhm Cdiff assay has demonstrated a high sensitivity and specificity for detecting Clostridium difficile. Recently, the BD Max platform, using the same principles as BD GeneOhm, has become available in Australia. This study aimed to investigate the sensitivity and specificity of BD Max Cdiff assay for the detection of toxigenic C. difficile in an Australian setting. Between December 2013 and January 2014, 406 stool specimens from 349 patients were analysed with the BD Max Cdiff assay. Direct and enrichment toxigenic culture were performed on bioMérieux ChromID C. difficile agar as a reference method. isolates from specimens with discrepant results were further analysed with an in-house PCR to detect the presence of toxin genes. The overall prevalence of toxigenic C. difficile was 7.2%. Concordance between the BD Max assay and enrichment culture was 98.5%. The sensitivity, specificity, positive predictive value and negative predictive value for the BD Max Cdiff assay were 95.5%, 99.0%, 87.5% and 99.7%, respectively, when compared to direct culture, and 91.7%, 99.0%, 88.0% and 99.4%, respectively, when compared to enrichment culture. The new BD Max Cdiff assay appeared to be an excellent platform for rapid and accurate detection of toxigenic C. difficile.

  4. Clostridium difficile and pediatric inflammatory bowel disease

    DEFF Research Database (Denmark)

    Martinelli, Massimo; Strisciuglio, Caterina; Veres, Gabor

    2014-01-01

    BACKGROUND: Clostridium difficile infection is associated with pediatric inflammatory bowel disease (IBD) in several ways. We sought to investigate C. difficile infection in pediatric patients with IBD in comparison with a group of children with celiac disease and to evaluate IBD disease course o...

  5. Stop C. difficile Infections PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second PSA is based on the March 2012 CDC Vital Signs report. C. difficile is a germ that causes diarrhea linked to 14,000 deaths in the US each year. This podcast helps health care professionals learn how to prevent C. difficile infections.

  6. Clostridial Binary Toxins: Iota and C2 Family Portraits

    Science.gov (United States)

    Stiles, Bradley G.; Wigelsworth, Darran J.; Popoff, Michel R.; Barth, Holger

    2011-01-01

    There are many pathogenic Clostridium species with diverse virulence factors that include protein toxins. Some of these bacteria, such as C. botulinum, C. difficile, C. perfringens, and C. spiroforme, cause enteric problems in animals as well as humans. These often fatal diseases can partly be attributed to binary protein toxins that follow a classic AB paradigm. Within a targeted cell, all clostridial binary toxins destroy filamentous actin via mono-ADP-ribosylation of globular actin by the A component. However, much less is known about B component binding to cell-surface receptors. These toxins share sequence homology amongst themselves and with those produced by another Gram-positive, spore-forming bacterium also commonly associated with soil and disease: Bacillus anthracis. This review focuses upon the iota and C2 families of clostridial binary toxins and includes: (1) basics of the bacterial source; (2) toxin biochemistry; (3) sophisticated cellular uptake machinery; and (4) host–cell responses following toxin-mediated disruption of the cytoskeleton. In summary, these protein toxins aid diverse enteric species within the genus Clostridium. PMID:22919577

  7. Comparing the economic and health benefits of different approaches to diagnosing Clostridium difficile infection.

    Science.gov (United States)

    Bartsch, Sarah M; Umscheid, Craig A; Nachamkin, Irving; Hamilton, Keith; Lee, Bruce Y

    2015-01-01

    Accurate diagnosis of Clostridium difficile infection (CDI) is essential to effectively managing patients and preventing transmission. Despite the availability of several diagnostic tests, the optimal strategy is debatable and their economic values are unknown. We modified our previously existing C. difficile simulation model to determine the economic value of different CDI diagnostic approaches from the hospital perspective. We evaluated four diagnostic methods for a patient suspected of having CDI: 1) toxin A/B enzyme immunoassay, 2) glutamate dehydrogenase (GDH) antigen/toxin AB combined in one test, 3) nucleic acid amplification test (NAAT), and 4) GDH antigen/toxin AB combination test with NAAT confirmation of indeterminate results. Sensitivity analysis varied the proportion of those tested with clinically significant diarrhoea, the probability of CDI, NAAT cost and CDI treatment delay resulting from a false-negative test, length of stay and diagnostic sensitivity and specificity. The GDH/toxin AB plus NAAT approach leads to the timeliest treatment with the fewest unnecessary treatments given, resulted in the best bed management and generated the lowest cost. The NAAT-alone approach also leads to timely treatment. The GDH/toxin AB diagnostic (without NAAT confirmation) approach resulted in a large number of delayed treatments, but results in the fewest secondary colonisations. Results were robust to the sensitivity analysis. Choosing the right diagnostic approach is a matter of cost and test accuracy. GDH/toxin AB plus NAAT diagnosis led to the timeliest treatment and was the least costly. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. Diversity of moxifloxacin resistance during a nosocomial outbreak of a predominantly ribotype ARU 027 Clostridium difficile diarrhea.

    Science.gov (United States)

    Carman, Robert J; Genheimer, Christopher W; Rafii, Fatemeh; Park, Miseon; Hiltonsmith, Megan F; Lyerly, David M

    2009-12-01

    To characterize the extent and diversity of moxifloxacin resistance among Clostridium difficile isolates recovered during a predominantly Anaerobe Reference Unit (ARU) ribotype 027-associated nosocomial outbreak of antibiotic associated diarrhea we measured the susceptibility of 34 field isolates and 6 laboratory strains of C. difficile to moxifloxacin. We ribotyped the isolates as well as assaying them by PCR for the metabolic gene, gdh, and the virulence genes, tcdA, tcdB, tcdC, cdtA and cdtB. All the laboratory isolates, including the historical ARU 027 isolate Cd196, were susceptible to moxifloxacin (or=16 microg/mL (high resistance). We sequenced the quinolone resistance determining regions of gyrA (position 71-460) and gyrB (position 1059-1448) from two susceptible laboratory strains, all five isolates with moderate resistance and two highly resistant isolates. Two highly resistant isolates (Pitt 40, ribotype ARU 027 and Pitt 33, ribotype ARU 001) had the same C245T (Thr(82)Delta Ile) mutation. No other changes were seen. Amplification with primer pairs specific for the C245T mutant gyrA and for the wild type gene respectively confirmed all 16 highly resistant ARU 027 isolates, as well as the highly resistant isolates from other ribotypes, had the C245T mutation and that the mutation was absent from all other isolates. Among the five isolates with moderate resistance we found combinations of mutations within gyrA (T128A, Val(43)Delta Asp and G349T, Ala(117)Delta Ser) and gyrB (G1276A, Arg(426)Delta Asn). The G1396A (Glu(466)Delta Lys) mutation was not associated with increased resistance.

  9. Variations in TcdB activity and the hypervirulence of emerging strains of Clostridium difficile.

    Directory of Open Access Journals (Sweden)

    Jordi M Lanis

    2010-08-01

    Full Text Available Hypervirulent strains of Clostridium difficile have emerged over the past decade, increasing the morbidity and mortality of patients infected by this opportunistic pathogen. Recent work suggested the major C. difficile virulence factor, TcdB, from hypervirulent strains (TcdB(HV was more cytotoxic in vitro than TcdB from historical strains (TcdB(HIST. The current study investigated the in vivo impact of altered TcdB tropism, and the underlying mechanism responsible for the differences in activity between the two forms of this toxin. A combination of protein sequence analyses, in vivo studies using a Danio rerio model system, and cell entry combined with fluorescence assays were used to define the critical differences between TcdB(HV and TcdB(HIST. Sequence analysis found that TcdB was the most variable protein expressed from the pathogenicity locus of C. difficile. In line with these sequence differences, the in vivo effects of TcdB(HV were found to be substantially broader and more pronounced than those caused by TcdB(HIST. The increased toxicity of TcdB(HV was related to the toxin's ability to enter cells more rapidly and at an earlier stage in endocytosis than TcdB(HIST. The underlying biochemical mechanism for more rapid cell entry was identified in experiments demonstrating that TcdB(HV undergoes acid-induced conformational changes at a pH much higher than that of TcdB(HIST. Such pH-related conformational changes are known to be the inciting step in membrane insertion and translocation for TcdB. These data provide insight into a critical change in TcdB activity that contributes to the emerging hypervirulence of C. difficile.

  10. Key Research Issues in Clostridium difficile

    Directory of Open Access Journals (Sweden)

    George Zhanel

    2005-01-01

    Full Text Available Clostridium difficile is an emerging pathogen that causes C difficile-associated diarrhea, an important nosocomial infection. Control of this infection remains a challenge, and much needs to be determined about the antimicrobial resistance of the organism, antibiotic stewardship, contamination of the patient environment, and various host factors that determine susceptibility or resistance to infection. A national symposium focusing on C difficile infections, the Clostridium difficile Symposium on Emerging Issues and Research, was hosted on November 23, 2004, by the Department of Medical Microbiology and Infectious Diseases at the University of Manitoba, Winnipeg, Manitoba, in partnership with the Canadian Institutes of Health Research. This symposium, which aimed to summarize key research issues regarding C difficile infections in Canada, had the following objectives: to provide a forum for learning and discussion about C difficile and its impact on the health of Canadians; to identify the key research issues that should be addressed; and to explore potential research funding opportunities and collaboration. The present report summarizes key research issues identified for C difficile infections in Canada by addressing four major themes: diagnosis and surveillance, infection prevention and control, antibiotic stewardship, and clinical management.

  11. Clostridium difficile in Retail Meats

    Centers for Disease Control (CDC) Podcasts

    2009-04-16

    Clostridium difficile is a common cause of diarrhea in healthcare settings but little is known about what causes cases in the community. In this podcast, CDC's Dr. L. Clifford McDonald discusses two papers in the May 2009 edition of Emerging Infectious Diseases that explore whether the organism could be found in meat samples purchased in grocery stores in Arizona and Canada.  Created: 4/16/2009 by Emerging Infectious Diseases.   Date Released: 4/16/2009.

  12. Clostridium difficile in Humans and Food Animals

    Centers for Disease Control (CDC) Podcasts

    2008-06-30

    Clostridium difficile is an antibiotic-resistant bacterium that causes diarrhea and sometimes serious intestinal illnesses. In recent years, C. difficile infections have been increasing in number and severity, including among some people outside healthcare settings. In this podcast, CDC's Dr. Michael Jhung discusses his recent study that looked at a new, increasingly prevalent strain of C. difficile in people and compared it to a strain historically found in animals to see whether the two might be linked. The study is published in the July 2008 issue of Emerging Infectious Diseases.  Created: 6/30/2008 by Emerging Infectious Diseases.   Date Released: 7/3/2008.

  13. Clostridium difficile in Humans and Food Animals

    Centers for Disease Control (CDC) Podcasts

    Clostridium difficile is an antibiotic-resistant bacterium that causes diarrhea and sometimes serious intestinal illnesses. In recent years, C. difficile infections have been increasing in number and severity, including among some people outside healthcare settings. In this podcast, CDC's Dr. Michael Jhung discusses his recent study that looked at a new, increasingly prevalent strain of C. difficile in people and compared it to a strain historically found in animals to see whether the two might be linked. The study is published in the July 2008 issue of Emerging Infectious Diseases.

  14. A CDT-Based Heuristic Zone Design Approach for Economic Census Investigators

    Directory of Open Access Journals (Sweden)

    Changixu Cheng

    2015-01-01

    Full Text Available This paper addresses a special zone design problem for economic census investigators that is motivated by a real-world application. This paper presented a heuristic multikernel growth approach via Constrained Delaunay Triangulation (CDT. This approach not only solved the barriers problem but also dealt with the polygon data in zoning procedure. In addition, it uses a new heuristic method to speed up the zoning process greatly on the premise of the required quality of zoning. At last, two special instances for economic census were performed, highlighting the performance of this approach.

  15. Human geminin promotes pre-RC formation and DNA replication by stabilizing CDT1 in mitosis

    DEFF Research Database (Denmark)

    Ballabeni, Andrea; Melixetian, Marina; Zamponi, Raffaella

    2004-01-01

    -mediated degradation by inhibiting its ubiquitination. In particular, Geminin ensures basal levels of CDT1 during S phase and its accumulation during mitosis. Consistently, inhibition of Geminin synthesis during M phase leads to impairment of pre-RC formation and DNA replication during the following cell cycle....... Moreover, we show that inhibition of CDK1 during mitosis, and not Geminin depletion, is sufficient for premature formation of pre-RCs, indicating that CDK activity is the major mitotic inhibitor of licensing in human cells. Taken together with recent data from our laboratory, our results demonstrate...

  16. Inhibition of NEDD8-activating enzyme induces rereplication and apoptosis in human tumor cells consistent with deregulating CDT1 turnover.

    Science.gov (United States)

    Milhollen, Michael A; Narayanan, Usha; Soucy, Teresa A; Veiby, Petter O; Smith, Peter G; Amidon, Benjamin

    2011-04-15

    Loss of NEDD8-activating enzyme (NAE) function by siRNA knockdown or inhibition by the small molecule NAE inhibitor MLN4924 leads to increased steady-state levels of direct Cullin-RING ligase (CRL) substrates by preventing their ubiquitination and proteasome-dependent degradation. Many of these CRL substrates are involved in cell cycle progression, including a critical DNA replication licensing factor CDT1. Cell cycle analysis of asynchronous and synchronous cultures after NAE inhibition revealed effects on cell cycle distribution and activation of DNA break repair signaling pathways similar to that reported for CDT1 overexpression. The siRNA knockdown of cullins critical for the turnover of CDT1 recapitulated the aberrant rereplication phenotype while CDT1 knockdown was suppressing. Although NAE inhibition leads to deregulation of many CRL substrates, these data demonstrate that CDT1 accumulation mediates the DNA rereplication phenotype resulting from loss of NAE function. DNA rereplication is an unrecoverable cellular insult and the small molecule inhibitor MLN4924, currently in phase I trials, represents an unprecedented opportunity to explore this mechanism of cytotoxicity for the treatment of cancer. ©2011 AACR.

  17. CLINICAL AND EPIDEMIOLOGIC CONSIDERATIONS OF CLOSTRIDIUM DIFFICILE IN HARBOR SEALS (PHOCA VITULINA) AT A MARINE MAMMAL REHABILITATION CENTER.

    Science.gov (United States)

    Anderson, Chelsea E; Haulena, Martin; Zabek, Erin; Habing, Gregory; Raverty, Stephen

    2015-06-01

    Between 1998 and 2008, 15 cases of segmental to diffuse hemorrhagic to necrohemorrhagic enterocolitis were diagnosed in neonatal and weaned juvenile harbor seals (Phoca vitulina) presented from the Vancouver Aquarium Marine Mammal Rescue Centre for rehabilitation. Based on a combination of gross pathology, histopathology, bacterial isolation, and toxin testing, Clostridium difficile enterocolitis was diagnosed. Most pups were anorexic or inappetant and died acutely with few other premonitory signs. Due to ongoing clinical concerns and possible emergence of this pathogen at the facility, efforts to better characterize the disease and understand the epidemiology of C. difficile was initiated in 95 harbor seal pups presented for rehabilitation in a single stranding season. Fecal samples were collected on admission, following completion of antibiotic treatment, and also prerelease or postmortem. All samples were collected fresh and submitted either directly or stored frozen. Fecal samples were inoculated into selective media for culture and screened by enzyme-linked immunosorbant assay (ELISA) for C. difficile toxins A, B, or both. Results of the 95 seals in the study were as follows: on hospital admit 72 seals were sampled, 10 were culture positive, 12 were ELISA positive; following antibiotic therapy 46 seals were sampled noting three culture positive and nine ELISA positive; prior to release 58 seals were sampled noting zero culture positive and one ELISA positive; and on postmortem exam seven seals were sampled noting zero culture positive and two ELISA positive. Clostridium difficile was not deemed to be the cause of death in any of the animals. Although the exact mechanism of disease is unknown, this study suggests that C. difficile infection is not a significant cause of mortality and may be part of the normal flora in harbor seals undergoing rehabilitation. Morbidity and mortality from this bacterium can likely be minimized by judicious use of antibiotics

  18. Detection of enterotoxin A and cytotoxin B, and isolation of Clostridium difficile in piglets in Minas Gerais, Brazil Detecção da enterotoxina A e citotoxina B e isolamento de Clostridium difficile em leitões em Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    Rodrigo Otávio Silveira Silva

    2011-08-01

    Full Text Available Clostridium difficile has emerged as a major cause of neonatal colitis in piglets, displacing classic bacterial pathogens. However, there is no information regarding the distribution of this microorganism in pig farms in Brazil. In the present study, the presence of toxins A/B and of C. difficile strains in stool samples from 60 diarrheic or non-diarrheic newborn piglets (one to seven days old, from 15 different farms, was studied. The presence of toxins A/B was detected by ELISA and PCR was used to identify toxin A, toxin B and binary toxin gene in each isolated strain. C. difficile A/B toxins were detected in ten samples (16.7%. Of these, seven were from diarrheic and three were from non-diarrheic piglets. C. difficile was recovered from 12 out of 60 (20% fecal samples. Of those, three strains were non-toxigenic (A-B- and nine were toxigenic. Of the nine toxigenic strains, four were A+B+ strains and five were A-B+ strains. The presence of binary toxin observed in the present study was much higher (50% than in previously reported studies. All three non-toxigenic strains were isolated from otherwise healthy piglets. The results suggest the occurrence of neonatal diarrhea by C. difficile in farms in Brazil.Clostridium difficile tem sido relatado como o principal causador de colite neonatal em suínos. Apesar da crescente importância deste agente, não há dados sobre infecções causadas por C. difficile em suínos no Brasil. O objetivo do presente estudo foi detectar as toxinas A/B e isolar C. difficile a partir de 60 amostras de fezes de leitões diarreicos ou apararentemente saudáveis, com no máximo sete dias de vida, e oriundos de 15 granjas diferentes. As toxinas A/B foram detectadas por ELISA e uma PCR multiplex foi utilizada para detecção dos genes responsáveis pela codificação das toxinas A, B e toxina binária. As toxinas A/B de C. difficile foram detectadas em dez amostras de fezes (16.7%. Dessas, sete eram de animais diarreicos

  19. Nieuwe mogelijkheden bij Clostridium difficile-infecties

    NARCIS (Netherlands)

    van Nood, Els; Keller, Josbert J.; Kuijper, Ed J.; Speelman, Peter

    2013-01-01

    Currently available broad spectrum antibiotics are not sufficiently effective against recurrent Clostridium difficile infections (CDI). Donor faecal microbiota transplantation is a very effective treatment for second and recurrent infection but is time-consuming and requires careful screening of

  20. Stop C. difficile Infections PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2012-03-06

    This 60 second PSA is based on the March 2012 CDC Vital Signs report. C. difficile is a germ that causes diarrhea linked to 14,000 deaths in the US each year. This podcast helps health care professionals learn how to prevent C. difficile infections.  Created: 3/6/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/6/2012.

  1. The economic burden of Clostridium difficile

    Science.gov (United States)

    McGlone, S. M.; Bailey, R. R.; Zimmer, S. M.; Popovich, M. J.; Tian, Y.; Ufberg, P.; Muder, R. R.; Lee, B. Y.

    2013-01-01

    Although Clostridium difficile (C. difficile) is the leading cause of infectious diarrhoea in hospitalized patients, the economic burden of this major nosocomial pathogen for hospitals, third-party payers and society remains unclear. We developed an economic computer simulation model to determine the costs attributable to healthcare-acquired C. difficile infection (CDI) from the hospital, third-party payer and societal perspectives. Sensitivity analyses explored the effects of varying the cost of hospitalization, C. difficile-attributable length of stay, and the probability of initial and secondary recurrences. The median cost of a case ranged from $9179 to $11 456 from the hospital perspective, $8932 to $11 679 from the third-party payor perspective, and $13 310 to $16 464 from the societal perspective. Most of the costs incurred were accrued during a patient’s primary CDI episode. Hospitals with an incidence of 4.1 CDI cases per 100 000 discharges would incur costs ≥$3.2 million (hospital perspective); an incidence of 10.5 would lead to costs ≥$30.6 million. Our model suggests that the annual US economic burden of CDI would be ≥$496 million (hospital perspective), ≥$547 million (third-party payer perspective) and ≥$796 million (societal perspective). Our results show that C. difficile infection is indeed costly, not only to third-party payers and the hospital, but to society as well. These results are consistent with current literature citing C. difficile as a costly disease. PMID:21668576

  2. Antibiotic prescribing policy and Clostridium difficile diarrhoea.

    LENUS (Irish Health Repository)

    O'Connor, K A

    2012-02-03

    BACKGROUND: Broad-spectrum antibiotics, particularly intravenous cephalosporins, are associated with Clostridium difficile diarrhoea. Diarrhoea due to C. difficile is a growing problem in hospitals, especially among elderly patients. AIM: To establish whether changing an antibiotic policy with the aim of reducing the use of injectable cephalosporins leads to a reduction in the incidence of C. difficile diarrhoea in elderly patients. DESIGN: Retrospective analysis. METHODS: A group of patients who were subject to the new antibiotic policy from the period following July 2000, were compared with patients who were admitted prior to July 2000 and were not subject to the new policy. Infections, antibiotic prescriptions and mortality rates were determined from case notes, and C. difficle diarrhoea rates from microbiological data. RESULTS: Intravenous cephalosporin use fell from 210 to 28 defined daily doses (p < 0.001) following the change in antibiotic policy, with a corresponding increase in piperacillin-tazobactam (p < 0.001) and moxifloxacin (p < 0.001) use. The new policy led to a significant reduction in C. difficile diarrhoea cases. The relative risk of developing C. difficile infection with the old policy compared to the new policy was 3.24 (95%CI 1.07-9.84, p = 0.03). DISCUSSION: The antibiotic policy was successfully introduced into an elderly care service. It reduced both intravenous cephalosporin use and C. difficile diarrhoea.

  3. Fatal case of hemolytic-uremic syndrome in an adult due to a rare serogroup O91 Entero hemorrhagic Escherichia coli associated with a Clostridium difficile infection. More than meets the eye

    Directory of Open Access Journals (Sweden)

    Thomas Guillard

    2015-08-01

    Full Text Available Hemolytic-uremic syndrome due to enterohemorrhagic Escherichia coli, belonging to serogroup O91 has rarely been described. We report here a case of post-diarrheal HUS due to EHEC O91 in an elderly patient for whom diagnosis was delayed given a previously diagnosed C. difficile infection. This case highlights the usefulness of Shiga-toxin detection.

  4. Doxycycline and Tigecycline: Two Friendly Drugs with a Low Association with Clostridium Difficile Infection

    Directory of Open Access Journals (Sweden)

    Yuan-Pin Hung

    2015-06-01

    Full Text Available Clostridium difficile infection (CDI is known to be associated with prior exposure to many classes of antibiotics. Standard therapy for CDI (i.e., metronidazole and vancomycin is associated with high recurrence rates. Although tetracycline derivatives such as tetracycline, doxycycline or tigecycline are not the standard therapeutic choices for CDI, they may serve as an alternative or a component of combination therapy. Previous tetracycline or doxycycline usage had been shown to have less association with CDI development. Tigecycline, a broad-spectrum glycylcycline with potency against many gram-positive or gram-negative pathogens, had been successfully used to treat severe or refractory CDI. The in vitro susceptibility of C. difficile clinical isolates to tigecycline in many studies showed low minimal inhibitory concentrations. Tigecycline can suppress in vitro toxin production in both historical and hypervirulent C. difficile strains and reduce spore production in a dose-dependent manner. Tetracycline compounds such as doxycycline, minocycline, and tigecycline possess anti-inflammatory properties that are independent of their antibiotic activity and may contribute to their therapeutic effect for CDI. Although clinical data are limited, doxycycline is less likely to induce CDI, and tigecycline can be considered one of the therapeutic choices for severe or refractory CDI.

  5. Clostridium difficile Infection Worsens the Prognosis of Ulcerative Colitis

    Directory of Open Access Journals (Sweden)

    María E Negrón

    2014-01-01

    Full Text Available BACKGROUND: The impact of Clostridium difficile infections among ulcerative colitis (UC patients is well characterized. However, there is little knowledge regarding the association between C difficile infections and postoperative complications among UC patients.

  6. Clostridium difficile suppresses colonic vasoactive intestinal peptide associated with altered motility

    Directory of Open Access Journals (Sweden)

    A. Nassif

    1995-01-01

    Full Text Available We investigated whether Clostridium difficile toxin alters colonic tissue levels of vasoactive intestinal peptide (VIP at the expense of changes in colonic motility in the isolated perfused rabbit left colon. Colonic inflammation was induced by the intracolonic administration of 10−8 M C. difflcile toxin. Strain gauge transducers were sewn onto the serosal surface of the colon to evaluate colonic motility. C. difflcile administration produced histologic changes consistent with epithelial damage. This was associated with an increased production of prostaglandin E2 and thromboxane B2. Tissue levels of VIP but not substance P were significantly reduced. This was associated with an increased number of contractions per minute and an average force of each colonic contraction. These results suggest that tissue levels of VIP are suppressed by C. difflcile and may participate in colonic dysmotility during active inflammation.

  7. Imipenem-induced clostridium difficile diarrhea in a patient with chronic renal failure

    Directory of Open Access Journals (Sweden)

    R Enríquez

    2011-01-01

    Full Text Available An 80-year-old man was diagnosed to have pneumonia and advanced chronic kidney disease. He presented with anuria and hemodialysis, by temporary femoral catheter, was initiated. He was empirically treated with imipenem/cilastatin 500 mg/24 h after hemodialysis. After 10 days of antibiotic intake, he developed severe diarrhea. Diagnosis of Clostridium difficile (CD-associated diarrhea was confirmed by detection of the toxins A and B in his stool. Imipenem therapy was discontinued; Vancomycin 500 mg orally every 6 h and 1000 mg per rectum every day was added. After two weeks of this treatment, the patient reported complete resolution of the diarrhea and stool samples were negative for Clostridium toxin. In this case, the most possible cause of CD colitis was considered to be imipenem because of the temporal relationship between exposure to the drug and onset of symptoms.

  8. Clostridium difficile infection in Europe: a hospital-based survey

    DEFF Research Database (Denmark)

    Bauer, Martijn P; Notermans, Daan W; van Benthem, Birgit H B

    2011-01-01

    Little is known about the extent of Clostridium difficile infection in Europe. Our aim was to obtain a more complete overview of C difficile infection in Europe and build capacity for diagnosis and surveillance.......Little is known about the extent of Clostridium difficile infection in Europe. Our aim was to obtain a more complete overview of C difficile infection in Europe and build capacity for diagnosis and surveillance....

  9. Man and pigs: sharing the same C. difficile

    NARCIS (Netherlands)

    Keessen, E.C.

    2013-01-01

    Clostridium difficile is an anaerobic spore forming gram-positive bacterium. Infection with C. difficile may lead in humans to symptomless carriership, but may also lead to diarrhea varying in severity from mild to life-threatening pseudomembraneous colitis. C. difficile spores can survive for long

  10. Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.

    Directory of Open Access Journals (Sweden)

    Iryna Schlackow

    Full Text Available Changing clinical impact, as virulent clones replace less virulent ones, is a feature of many pathogenic bacterial species and can be difficult to detect. Consequently, innovative techniques monitoring infection severity are of potential clinical value.We studied 5,551 toxin-positive and 20,098 persistently toxin-negative patients tested for Clostridium difficile infection between February 1998 and July 2009 in a group of hospitals based in Oxford, UK, and investigated 28-day mortality and biomarkers of inflammation (blood neutrophil count, urea, and creatinine concentrations collected at diagnosis using iterative sequential regression (ISR, a novel joinpoint-based regression technique suitable for serial monitoring of continuous or dichotomous outcomes. Among C. difficile toxin-positive patients in the Oxford hospitals, mean neutrophil counts on diagnosis increased from 2003, peaked in 2006-2007, and then declined; 28-day mortality increased from early 2006, peaked in late 2006-2007, and then declined. Molecular typing confirmed these changes were likely due to the ingress of the globally distributed severe C. difficile strain, ST1. We assessed the generalizability of ISR-based severity monitoring in three ways. First, we assessed and found strong (p<0.0001 associations between isolation of the ST1 severe strain and higher neutrophil counts at diagnosis in two unrelated large multi-centre studies, suggesting the technique described might be useful elsewhere. Second, we assessed and found similar trends in a second group of hospitals in Birmingham, UK, from which 5,399 cases were analysed. Third, we used simulation to assess the performance of this surveillance system given the ingress of future severe strains under a variety of assumptions. ISR-based severity monitoring allowed the detection of the severity change years earlier than mortality monitoring.Automated electronic systems providing early warning of the changing severity of infectious

  11. Clostridium difficile Diarrhea in the Elderly: Current Issues and Management Options.

    Science.gov (United States)

    Mizusawa, Masako; Doron, Shira; Gorbach, Sherwood

    2015-08-01

    Clostridium difficile infection (CDI) is the most common cause of infectious diarrhea in healthcare settings. Along with antimicrobial exposure, advanced age has been shown to be a significant risk factor for the development and recurrence of, and mortality from, CDI. The substantial burden of CDI in the elderly may be related to frequent healthcare exposure, the necessity for more medications, altered intestinal microbiota, and complicated comorbidities. A diagnosis of CDI is based on evidence of toxin, or the C. difficile organism itself, in a stool sample in the presence of clinical signs and symptoms. Only symptomatic patients should be tested for CDI, and routine surveillance or repeat testing on asymptomatic patients as a test of cure is discouraged. Antibiotic discontinuation alone can improve or resolve CDI in some patients, and concomitant use of antibiotics is associated with decreased response to CDI treatment. Metronidazole, vancomycin, and fidaxomicin are the therapeutic agents currently available for CDI, with the selection of these agents being based on disease severity, history of recurrence, and cost. The recurrence rate after initial treatment is 20-30%. The first recurrence can be treated with the same therapeutic agent and, for subsequent recurrences, vancomycin in a tapered and/or pulsed regimen is recommended. Fecal microbiota transplantation has shown remarkable effectiveness for recurrent anti-refractory CDI, although caution is advised in treating immunocompromised hosts and those with toxic megacolon. C. difficile can be transmitted directly and indirectly via contact with patients or their environment; therefore, isolation precautions should be initiated at the first suspicion of CDI. C. difficile spores can survive for a long time on environmental surfaces, and the patient's room and all equipment used in the room should be disinfected. In order to manage CDI in the elderly, timely diagnosis, appropriate treatment based on severity of

  12. The Role of the CRL4Cdt2 Target Spd1 in Chromosome Segregation in Fission Yeast

    DEFF Research Database (Denmark)

    Landvad, Katrine

    Ddb1, a component of the E3 ubiquitin ligase CRL4Cdt2, is needed for proper chromosome segregation in fission yeast as ddb1 deleted cells show unequal distribution of DNA to daughter cells and sensitivity to the microtubule destabilising drug TBZ. In this study we show that Δddb1 cells have...

  13. Lactobacillus rhamnosus L34 and Lactobacillus casei L39 suppress Clostridium difficile-induced IL-8 production by colonic epithelial cells

    Science.gov (United States)

    2014-01-01

    Background Clostridium difficile is the main cause of hospital-acquired diarrhea and colitis known as C. difficile-associated disease (CDAD).With increased severity and failure of treatment in CDAD, new approaches for prevention and treatment, such as the use of probiotics, are needed. Since the pathogenesis of CDAD involves an inflammatory response with a massive influx of neutrophils recruited by interleukin (IL)-8, this study aimed to investigate the probiotic effects of Lactobacillus spp. on the suppression of IL-8 production in response to C. difficile infection. Results We screened Lactobacillus conditioned media from 34 infant fecal isolates for the ability to suppress C. difficile-induced IL-8 production from HT-29 cells. Factors produced by two vancomycin-resistant lactobacilli, L. rhamnosus L34 (LR-L34) and L.casei L39 (LC-L39), suppressed the secretion and transcription of IL-8 without inhibiting C. difficile viability or toxin production. Conditioned media from LR-L34 suppressed the activation of phospho-NF-κB with no effect on phospho-c-Jun. However, LC-L39 conditioned media suppressed the activation of both phospho-NF-κB and phospho-c-Jun. Conditioned media from LR-L34 and LC-L39 also decreased the production of C. difficile-induced GM-CSF in HT-29 cells. Immunomodulatory factors present in the conditioned media of both LR-L34 and LC-L39 are heat-stable up to 100°C and > 100 kDa in size. Conclusions Our results suggest that L. rhamnosus L34 and L. casei L39 each produce factors capable of modulating inflammation stimulated by C. difficile. These vancomycin-resistant Lactobacillus strains are potential probiotics for treating or preventing CDAD. PMID:24989059

  14. Lactobacillus rhamnosus L34 and Lactobacillus casei L39 suppress Clostridium difficile-induced IL-8 production by colonic epithelial cells.

    Science.gov (United States)

    Boonma, Prapaporn; Spinler, Jennifer K; Venable, Susan F; Versalovic, James; Tumwasorn, Somying

    2014-07-02

    Clostridium difficile is the main cause of hospital-acquired diarrhea and colitis known as C. difficile-associated disease (CDAD).With increased severity and failure of treatment in CDAD, new approaches for prevention and treatment, such as the use of probiotics, are needed. Since the pathogenesis of CDAD involves an inflammatory response with a massive influx of neutrophils recruited by interleukin (IL)-8, this study aimed to investigate the probiotic effects of Lactobacillus spp. on the suppression of IL-8 production in response to C. difficile infection. We screened Lactobacillus conditioned media from 34 infant fecal isolates for the ability to suppress C. difficile-induced IL-8 production from HT-29 cells. Factors produced by two vancomycin-resistant lactobacilli, L. rhamnosus L34 (LR-L34) and L.casei L39 (LC-L39), suppressed the secretion and transcription of IL-8 without inhibiting C. difficile viability or toxin production. Conditioned media from LR-L34 suppressed the activation of phospho-NF-κB with no effect on phospho-c-Jun. However, LC-L39 conditioned media suppressed the activation of both phospho-NF-κB and phospho-c-Jun. Conditioned media from LR-L34 and LC-L39 also decreased the production of C. difficile-induced GM-CSF in HT-29 cells. Immunomodulatory factors present in the conditioned media of both LR-L34 and LC-L39 are heat-stable up to 100°C and > 100 kDa in size. Our results suggest that L. rhamnosus L34 and L. casei L39 each produce factors capable of modulating inflammation stimulated by C. difficile. These vancomycin-resistant Lactobacillus strains are potential probiotics for treating or preventing CDAD.

  15. CD44 Promotes intoxication by the clostridial iota-family toxins.

    Science.gov (United States)

    Wigelsworth, Darran J; Ruthel, Gordon; Schnell, Leonie; Herrlich, Peter; Blonder, Josip; Veenstra, Timothy D; Carman, Robert J; Wilkins, Tracy D; Van Nhieu, Guy Tran; Pauillac, Serge; Gibert, Maryse; Sauvonnet, Nathalie; Stiles, Bradley G; Popoff, Michel R; Barth, Holger

    2012-01-01

    Various pathogenic clostridia produce binary protein toxins associated with enteric diseases of humans and animals. Separate binding/translocation (B) components bind to a protein receptor on the cell surface, assemble with enzymatic (A) component(s), and mediate endocytosis of the toxin complex. Ultimately there is translocation of A component(s) from acidified endosomes into the cytosol, leading to destruction of the actin cytoskeleton. Our results revealed that CD44, a multifunctional surface protein of mammalian cells, facilitates intoxication by the iota family of clostridial binary toxins. Specific antibody against CD44 inhibited cytotoxicity of the prototypical Clostridium perfringens iota toxin. Versus CD44(+) melanoma cells, those lacking CD44 bound less toxin and were dose-dependently resistant to C. perfringens iota, as well as Clostridium difficile and Clostridium spiroforme iota-like, toxins. Purified CD44 specifically interacted in vitro with iota and iota-like, but not related Clostridium botulinum C2, toxins. Furthermore, CD44 knockout mice were resistant to iota toxin lethality. Collective data reveal an important role for CD44 during intoxication by a family of clostridial binary toxins.

  16. Prevalence and characterization of enterotoxigenic Bacteroides fragilis and toxigenic Clostridium difficile in a Taipei emergency department.

    Science.gov (United States)

    Ji, Dar-Der; Huang, I-Hsiu; Lai, Chao-Chih; Wu, Fang-Tzy; Jiang, Donald Dah-Shyong; Hsu, Bing-Mu; Lin, Wei-Chen

    2017-02-01

    Enterotoxigenic Bacteroides fragilis (ETBF) and toxin-encoding Clostridium difficile (TXCD) are associated with gastroenteritis. Routine anaerobic blood culture for recovery of these anaerobic pathogens is not used for the detection of their toxins, especially for toxin-variant TXCD. The aim of this study was to investigate the prevalence and risk factors of the genotypes of these anaerobes in patients with acute diarrheal illnesses. The data and samples of 513 patients with gastroenteritis were collected in a Taipei emergency department from March 1, 2006 to December 31, 2009. Nonenterotoxigenic B. fragilis (NTBF) and ETBF and the toxin genotypes of TXCD were detected by molecular methods. The prevalence rates of NTBF, ETBF, and TXCD infections were 33.14%, 1.56%, and 2.34%, respectively. ETBF infections often occurred in the elderly (average age = 67.13 years) and during the cold, dry winters. TXCD infections were widely distributed in age and often occurred in the warm, wet springs and summers. The symptoms of ETBF-infected patients were significantly more severe than those of NTBF-infected patients. This study identified and analyzed the prevalence, risk factors, and clinical presentations of these anaerobic infections. Future epidemiologic and clinical studies are needed to understand the role of ETBF and TXCD in human gastroenteritis. Copyright © 2015. Published by Elsevier B.V.

  17. Clinical and microbiological characterization of Clostridium difficile infection in a tertiary care hospital in Shanghai, China.

    Science.gov (United States)

    Dong, Danfeng; Peng, Yibing; Zhang, Lihua; Jiang, Cen; Wang, Xuefeng; Mao, Enqiang

    2014-01-01

    Over the last decade, Clostridium difficile infection (CDI) has emerged as a significant nosocomial infection, yet little has been reported from China. This study aimed to characterize the clinical and microbiological features of CDI from a hospital in Shanghai. Patients with CDI seen between December 2010 and March 2013 were included in this study, of which clinical data were retrospectively collected. The microbiological features of corresponding isolates were analyzed including genotype by multi-locus sequence typing (MLST), antimicrobial susceptibility, toxin production, sporulation capacity, biofilm formation, and motility. Ninety-four cases of CDI were included during this study period, 12 of whom were severe cases. By reviewing the clinical data, all patients were treated empirically with proton pump inhibitor or antibiotics or both, and they were distributed widely across various wards, most frequently to the digestive ward (28/94, 29.79%). Comparing the severe with mild cases, no significant differences were found in the basic epidemiological data or the microbiological features. Among the 94 isolates, 31 were toxin A-negative toxin B-positive all genotyped as ST37. They generated fewer toxins and spores, as well as similar amounts of biofilm and motility percentages, but exhibited highest drug resistance to cephalosporins, quinolones, macrolide-lincosamide and streptogramin (MLSB), and tetracycline. No specific clinical genotype or microbiological features were found in severe cases; antimicrobial resistance could be the primary reason for epidemic strains leading to the dissemination and persistence of CDI.

  18. Epidemiology of Clostridium difficile Infection

    Science.gov (United States)

    DePestel, Daryl D.; Aronoff, David M.

    2014-01-01

    There has been dramatic change in the epidemiology of Clostridium difficile infection (CDI) since the turn of the 21st Century noted by a marked increase in incidence and severity, occurring at a disproportionately higher frequency in older patients. Historically considered a nosocomial infection associated with antibiotic exposure, CDI has now also emerged in the community in populations previously considered low risk. Emerging risk factors and disease recurrence represent continued challenges in the management of CDI. The increased incidence and severity associated with CDI has coincided with the emergence and rapid spread of a previously rare strain, ribotype 027. Recent data from the U.S. and Europe suggest the incidence of CDI may have reached a crescendo in recent years and is perhaps beginning to plateau. The acute-care direct costs of CDI were estimated to be $4.8 billion in 2008. However, nearly all the published studies have focused on CDI diagnosed and treated in acute-care hospital setting and fail to measure the burden outside the hospital, including recently discharged patients, outpatients, and those in long-term care facilities. Enhanced surveillance methods are needed to monitor the incidence, identify populations at risk, and characterize the molecular epidemiology of strains causing CDI. PMID:24064435

  19. Correlation between fecal calprotectin levels, disease severity and the hypervirulent ribotype 027 strain in patients with Clostridium difficile infection.

    Science.gov (United States)

    Peretz, Avi; Tkhawkho, Linda; Pastukh, Nina; Brodsky, Diana; Halevi, Chen Namimi; Nitzan, Orna

    2016-06-22

    Clostridium difficile is the most common infectious etiology of nosocomial diarrhea. Fecal calprotectin (fc) is a sensitive marker of intestinal inflammation, found to be associated with enteric bacterial infections and inflammatory bowel disease. We evaluated fc levels using a Chemiluminescent immunoassay method, in hospitalized patients with C. difficile infection (CDI) diagnosed by molecular stool examination and assessed correlation with virulent ribotype 027 strain infection, antibiotic susceptibility by gradient Etest strip performed on C. difficile colonies and clinical and laboratory measures of disease severity. Statistical analysis was performed for correlation of fc levels with clinical and laboratory parameters, disease severity and patient outcomes. Overall 29 patients with CDI were admitted at the Poria medical center in northern Israel, during June 2014-May 2015. Resistance to metronidazole was found in 3 (10.3 %) isolates and to vancomycin in 5 (17.2 %) isolates. Regarding patient outcomes, within 30 days of CDI diagnosis, recurrence of disease occurred in 10 (34.5 %) patients and 2 patients (6.9 %) died. Seven (24.1 %) isolates were C. difficile ribotype 027. Mean fc level was 331.4 μg/g (21-932). Higher fc levels were found in patients with C. difficile ribotype 027 (p clostridium severity score index (p = 0.0633). No correlation was found between fecal calprotectin levels and age, sex, functional status, community versus hospital acquired CDI, antibiotic susceptibility, fever, and creatinine levels. Our study highlights the fact that fc has a potential role as a biomarker of disease severity and binary toxin producing ribotype associated disease.

  20. Fidaxomicin in Clostridium difficile infection: latest evidence and clinical guidance.

    Science.gov (United States)

    Mullane, Kathleen

    2014-03-01

    The incidence of Clostridium difficile infection (CDI) has risen 400% in the last decade. It currently ranks as the third most common nosocomial infection. CDI has now crossed over as a community-acquired infection. The major failing of current therapeutic options for the management of CDI is recurrence of disease after the completion of treatment. Fidaxomicin has been proven to be superior to vancomycin in successful sustained clinical response to therapy. Improved outcomes may be due to reduced collateral damage to the gut microflora by fidaxomicin, bactericidal activity, inhibition of Clostridial toxin formation and inhibition of new sporulation. This superiority is maintained in groups previously reported as being at high risk for CDI recurrence including those: with relapsed infection after a single treatment course; on concomitant antibiotic therapy; aged >65 years; with cancer; and with chronic renal insufficiency. Because the acquisition cost of fidaxomicin far exceeds that of metronidazole or vancomycin, in order to rationally utilize this agent, it should be targeted to those populations who are at high risk for relapse and in whom the drug has demonstrated superiority. In this manuscript is reviewed the changing epidemiology of CDI, current treatment options for this infection, proposed benefits of fidaxomicin over currently available antimicrobial options, available analysis of cost effectiveness of the drug, and is given recommendations for judicious use of the drug based upon the available published literature.

  1. [Current treatment and epidemiology of Clostridium difficile infections].

    Science.gov (United States)

    Dinh, A; Bouchand, F; Le Monnier, A

    2015-09-01

    During the past 10years, Clostridium difficile infections (CDI) have become a major public health challenge. Their epidemiology has changed with a rise in the number of cases and an increase in severe episodes. Recurrence and failure of conventional treatments have become more common. Furthermore, a spread of CDI has been observed in the general population-involving subjects without the usual risk factors (unexposed to antibiotic treatment, young people, pregnant women, etc.). All these change are partially due to the emergence of the hypervirulent and hyperepidemic clone NAP1/B1/027. New therapeutic strategies (antimicrobial treatment, immunoglobulins, toxin chelation, fecal microbiota transplantation) are now available and conventional treatments (metronidazole and vancomycin) have been reevaluated with new recommendations. Recent studies show a better efficacy of vancomycin compared to metronidazole for severe episodes. Fidaxomicin is a novel antibiotic drug with interesting features, including an efficacy not inferior to vancomycin and a lower risk of recurrence. Finally, for multi-recurrent forms, fecal microbiota transplantation seems to be the best option. We present the available data in this review. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  2. Characteristics of cytotoxic necrotizing factor and cytolethal distending toxin producing Escherichia coli strains isolated from meat samples in Northern Ireland.

    Science.gov (United States)

    Kadhum, H J; Ball, H J; Oswald, E; Rowe, M T

    2006-08-01

    Swabs collected from pig, lamb and beef carcasses and samples of pork, lamb and beef mince were cultured for Escherichia coli strains. Strains harbouring cytotoxic necrotizing factors (CNF1 and 2) and cytolethal distending toxins (CDT-I,-II,-III and -IV) were identified in plate cultures of the isolates by colony hybridization with labelled probes and multiplex PCR assays. Simplex and multiplex PCR assays were used to further characterize the isolates to determine the presence of P, S and F17 fimbriae as well as afimbrial adhesins and haemolysin. The serotype was also determined where possible. Thirty strains with the capacity to code for CNF (4), CDT (24) or both (2) were isolated and characterized, and a wide range of associated factor patterns was observed. The methods utilized were successful in demonstrating the detection of viable strains with potentially significant pathogenic factors from human food sources.

  3. Botulinum toxin injection - larynx

    Science.gov (United States)

    Injection laryngoplasty; Botox - larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography - guided botulinum toxin treatment; Percutaneous indirect laryngoscopy - guided botulinum toxin treatment; ...

  4. Defense against Toxin Weapons

    National Research Council Canada - National Science Library

    Franz, David

    1998-01-01

    .... We typically fear what we do not understand. Although un- derstanding toxin poisoning is less useful in a toxin attack than knowledge of cold injury on an Arctic battlefield, information on any threat reduces its potential to harm...

  5. Clostridium difficile is an autotrophic bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Michael Köpke

    Full Text Available During the last decade, Clostridium difficile infection showed a dramatic increase in incidence and virulence in the Northern hemisphere. This incessantly challenging disease is the leading cause of antibiotic-associated and nosocomial infectious diarrhea and became life-threatening especially among elderly people. It is generally assumed that all human bacterial pathogens are heterotrophic organisms, being either saccharolytic or proteolytic. So far, this has not been questioned as colonization of the human gut gives access to an environment, rich in organic nutrients. Here, we present data that C. difficile (both clinical and rumen isolates is also able to grow on CO2+H2 as sole carbon and energy source, thus representing the first identified autotrophic bacterial pathogen. Comparison of several different strains revealed high conservation of genes for autotrophic growth and showed that the ability to use gas mixtures for growth decreases or is lost upon prolonged culturing under heterotrophic conditions. The metabolic flexibility of C. difficile (heterotrophic growth on various substrates as well as autotrophy could allow the organism in the gut to avoid competition by niche differentiation and contribute to its survival when stressed or in unfavorable conditions that cause death to other bacteria. This may be an important trait for the pathogenicity of C. difficile.

  6. The changing epidemiology of Clostridium difficile infections

    NARCIS (Netherlands)

    Freeman, J.; Bauer, M. P.; Baines, S. D.; Corver, J.; Fawley, W. N.; Goorhuis, B.; Kuijper, E. J.; Wilcox, M. H.

    2010-01-01

    The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI.

  7. Clostridium difficile infection in returning travellers

    NARCIS (Netherlands)

    Michal Stevens, A.; Esposito, Douglas H.; Stoney, Rhett J.; Hamer, Davidson H.; Flores-Figueroa, Jose; Bottieau, Emmanuel; Connor, Bradley A.; Gkrania-Klotsas, Effrossyni; Goorhuis, Abraham; Hynes, Noreen A.; Libman, Michael; Lopez-Velez, Rogelio; McCarthy, Anne E.; von Sonnenburg, Frank; Schwartz, Eli; van Genderen, Perry J. J.; Scott Benson, L.; Leung, Daniel T.

    2017-01-01

    There is increasing recognition of the contribution of community-acquired cases to the global burden of Clostridium difficile infection (CDI). The epidemiology of CDI among international travellers is poorly understood, and factors associated with international travel, such as antibiotic use and

  8. The anti-sigma factor TcdC modulates hypervirulence in an epidemic BI/NAP1/027 clinical isolate of Clostridium difficile.

    Directory of Open Access Journals (Sweden)

    Glen P Carter

    2011-10-01

    Full Text Available Nosocomial infections are increasingly being recognised as a major patient safety issue. The modern hospital environment and associated health care practices have provided a niche for the rapid evolution of microbial pathogens that are well adapted to surviving and proliferating in this setting, after which they can infect susceptible patients. This is clearly the case for bacterial pathogens such as Methicillin Resistant Staphylococcus aureus (MRSA and Vancomycin Resistant Enterococcus (VRE species, both of which have acquired resistance to antimicrobial agents as well as enhanced survival and virulence properties that present serious therapeutic dilemmas for treating physicians. It has recently become apparent that the spore-forming bacterium Clostridium difficile also falls within this category. Since 2000, there has been a striking increase in C. difficile nosocomial infections worldwide, predominantly due to the emergence of epidemic or hypervirulent isolates that appear to possess extended antibiotic resistance and virulence properties. Various hypotheses have been proposed for the emergence of these strains, and for their persistence and increased virulence, but supportive experimental data are lacking. Here we describe a genetic approach using isogenic strains to identify a factor linked to the development of hypervirulence in C. difficile. This study provides evidence that a naturally occurring mutation in a negative regulator of toxin production, the anti-sigma factor TcdC, is an important factor in the development of hypervirulence in epidemic C. difficile isolates, presumably because the mutation leads to significantly increased toxin production, a contentious hypothesis until now. These results have important implications for C. difficile pathogenesis and virulence since they suggest that strains carrying a similar mutation have the inherent potential to develop a hypervirulent phenotype.

  9. Molecular Epidemiology of Clostridium difficile Infection in Hospitalized Patients in Eastern China.

    Science.gov (United States)

    Jin, Dazhi; Luo, Yun; Huang, Chen; Cai, Jian; Ye, Julian; Zheng, Yi; Wang, Liqian; Zhao, Peng; Liu, Anbing; Fang, Weijia; Wang, Xianjun; Xia, Shichang; Jiang, Jianmin; Tang, Yi-Wei

    2017-03-01

    Few studies on risk factors for and transmission of Clostridium difficile infection (CDI) in China have been reported. A cross-sectional study was conducted for 3 years in eastern China. Consecutive stool specimens from hospitalized patients with diarrhea were cultured for C. difficile. C. difficile isolates from these patients then were analyzed for toxin genes, genotypes, and antimicrobial resistance. A severity score for the CDI in each patient was determined by a blinded review of the medical record, and these scores ranged from 1 to 6. A total of 397 out of 3,953 patients (10.0%) with diarrhea were found to have CDI. Severity of CDI was mild to moderate, and the average (± standard deviation) severity score was 2.61 ± 1.01. C. difficile was isolated from stool specimens in 432 (10.9%) of all the patients who had diarrhea. C. difficile genotypes were determined by multilocus sequence analysis and PCR ribotyping; sequence type 37 (ST37)/ribotype 017 (RT017) ( n = 68, 16.5%) was the dominant genotype. Eleven patients (16.2%) with this genotype had a CDI severity score of 5. Overall, three RTs and four STs were predominant; these genotypes were associated with significantly different antimicrobial resistance patterns in comparison to all genotypes (χ 2 = 79.56 to 97.76; P < 0.001). Independent risk factors associated with CDI included age greater than 55 years (odds ratio [95% confidence interval], 26.80 [18.76 to 38.29]), previous hospitalization (12.42 [8.85 to 17.43]), previous antimicrobial treatment within 8 weeks (150.56 [73.11 to 310.06]), hospital stay more than 3 days before sampling (2.34 [1.71 to 3.22]), undergoing chemotherapy (3.31 [2.22 to 4.92]), and undergoing abdominal surgery (4.82 [3.54 to 6.55]). CDI is clearly a problem in eastern China and has a prevalence of 10.0% in hospitalized patients. Among risk factors for CDI, the advanced age threshold was younger for Chinese patients than that reported for patients in developed countries

  10. Bioterrorism: toxins as weapons.

    Science.gov (United States)

    Anderson, Peter D

    2012-04-01

    The potential for biological weapons to be used in terrorism is a real possibility. Biological weapons include infectious agents and toxins. Toxins are poisons produced by living organisms. Toxins relevant to bioterrorism include ricin, botulinum, Clostridium perfrigens epsilson toxin, conotoxins, shigatoxins, saxitoxins, tetrodotoxins, mycotoxins, and nicotine. Toxins have properties of biological and chemical weapons. Unlike pathogens, toxins do not produce an infection. Ricin causes multiorgan toxicity by blocking protein synthesis. Botulinum blocks acetylcholine in the peripheral nervous system leading to muscle paralysis. Epsilon toxin damages cell membranes. Conotoxins block potassium and sodium channels in neurons. Shigatoxins inhibit protein synthesis and induce apoptosis. Saxitoxin and tetrodotoxin inhibit sodium channels in neurons. Mycotoxins include aflatoxins and trichothecenes. Aflatoxins are carcinogens. Trichothecenes inhibit protein and nucleic acid synthesis. Nicotine produces numerous nicotinic effects in the nervous system.

  11. Evaluation of the performance of C. DIFF QUIK CHEK COMPLETE and its usefulness in a hospital setting with a high prevalence of Clostridium difficile infection.

    Science.gov (United States)

    Chung, Hae-Sun; Lee, Miae

    2017-01-01

    Rapid and accurate diagnosis of Clostridium difficile infection (CDI) is crucial for patient care, infection control, and efficient surveillance. We evaluated C. DIFF QUIK CHEK COMPLETE (QCC; TechLab), which detects glutamate dehydrogenase (GDH) antigen (QCC-Ag) and toxin A/B (QCC-Tox) simultaneously, and compared it to the laboratory diagnostics for CDI currently in use in a tertiary hospital setting with a high prevalence of CDI. QCC, RIDASCREEN C. difficile toxin A/B assay (Toxin EIA; R-Biopharm AG), chromID C. difficile agar (bioMérieux) culture (ChromID culture), and Xpert C. difficile PCR assay (Xpert PCR; Cepheid) were performed according to the manufacturers' instructions. Performances of the assays were compared against that of Xpert PCR as a reference. Of the 231 loose stool specimens, 83 (35.9%) were positive by Xpert PCR. The sensitivity, specificity, and positive and negative predictive values were 97.6%, 93.9%, 90.0%, and 98.6%, respectively, for QCC-Ag and 55.4%, 100%, 100%, and 80.0%, respectively, for QCC-Tox. The median threshold cycle values of the QCC-Tox(+) specimens were lower than those of the QCC-Tox(-) specimens. Results of QCC as an initial screening test were confirmed in 81.0% (187/231) of samples; these specimens did not require further testing. QCC is a rapid, easy, and cost-effective method that would be a useful first-line screening assay for laboratory diagnosis of CDI in a tertiary hospital with a high prevalence of CDI. A two-step algorithm using QCC as an initial screening tool, followed by Xpert PCR as a confirmatory test, is a practical and cost-effective approach. Copyright © 2016 American Federation for Medical Research.

  12. Asymptomatic carriers contribute to nosocomial Clostridium difficile infection

    DEFF Research Database (Denmark)

    Blixt, Thomas; Gradel, Kim Oren; Homann, Christian

    2017-01-01

    BACKGROUND & AIMS: Nosocomial infection with Clostridium difficile pose a considerable problem despite numerous attempts by health care workers to reduce risk of transmission. Asymptomatic carriers of C difficile might spread their infection to other patients. We investigated the effects...... of of asymptomatic carriers on nosocomial C difficile infections. METHODS: We performed a population-based prospective cohort study at 2 university hospitals in Denmark, screening all patients for toxigenic C difficile in the intestine upon admittance, from October 1, 2012, to January 31, 2013. Screening results...... were blinded to patients, staff, and researchers. Patients were followed during their hospital stay by daily registration of wards and patient rooms. The primary outcomes were rate of C difficile infection in exposed and unexposed patients and factors associated with transmission. RESULTS: C difficile...

  13. Cdt1p, through its interaction with Mcm6p, is required for the formation, nuclear accumulation and chromatin loading of the MCM complex.

    Science.gov (United States)

    Wu, Rentian; Wang, Jiafeng; Liang, Chun

    2012-01-01

    Regulation of DNA replication initiation is essential for the faithful inheritance of genetic information. Replication initiation is a multi-step process involving many factors including ORC, Cdt1p, Mcm2-7p and other proteins that bind to replication origins to form a pre-replicative complex (pre-RC). As a prerequisite for pre-RC assembly, Cdt1p and the Mcm2-7p heterohexameric complex accumulate in the nucleus in G1 phase in an interdependent manner in budding yeast. However, the nature of this interdependence is not clear, nor is it known whether Cdt1p is required for the assembly of the MCM complex. In this study, we provide the first evidence that Cdt1p, through its interaction with Mcm6p with the C-terminal regions of the two proteins, is crucial for the formation of the MCM complex in both the cytoplasm and nucleoplasm. We demonstrate that disruption of the interaction between Cdt1p and Mcm6p prevents the formation of the MCM complex, excludes Mcm2-7p from the nucleus, and inhibits pre-RC assembly and DNA replication. Our findings suggest a function for Cdt1p in promoting the assembly of the MCM complex and maintaining its integrity by interacting with Mcm6p.

  14. Targeted ubiquitination of CDT1 by the DDB1-CUL4A-ROC1 ligase in response to DNA damage.

    Science.gov (United States)

    Hu, Jian; McCall, Chad M; Ohta, Tomohiko; Xiong, Yue

    2004-10-01

    Cullins assemble a potentially large number of ubiquitin ligases by binding to the RING protein ROC1 to catalyse polyubiquitination, as well as binding to various specificity factors to recruit substrates. The Cul4A gene is amplified in human breast and liver cancers, and loss-of-function of Cul4 results in the accumulation of the replication licensing factor CDT1 in Caenorhabditis elegans embryos and ultraviolet (UV)-irradiated human cells. Here, we report that human UV-damaged DNA-binding protein DDB1 associates stoichiometrically with CUL4A in vivo, and binds to an amino-terminal region in CUL4A in a manner analogous to SKP1, SOCS and BTB binding to CUL1, CUL2 and CUL3, respectively. As with SKP1-CUL1, the DDB1-CUL4A association is negatively regulated by the cullin-associated and neddylation-dissociated protein, CAND1. Recombinant DDB1 and CDT1 bind directly to each other in vitro, and ectopically expressed DDB1 bridges CDT1 to CUL4A in vivo. Silencing DDB1 prevented UV-induced rapid CDT1 degradation in vivo and CUL4A-mediated CDT1 ubiquitination in vitro. We suggest that DDB1 targets CDT1 for ubiquitination by a CUL4A-dependent ubiquitin ligase, CDL4A(DDB1), in response to UV irradiation.

  15. Efficacy and safety of fidaxomicin compared with oral vancomycin for the treatment of adults with Clostridium difficile-associated diarrhea: data from the OPT-80-003 and OPT-80-004 studies.

    Science.gov (United States)

    Chen, Luke F; Anderson, Deverick J

    2012-06-01

    Clostridium difficile is emerging as one of the most important and devastating pathogens affecting hospitalized populations around the world. The incidence of C. difficile infection is increasing and disease severity is worsening. Thus, an effective alternative to metronidazole and oral vancomycin is urgently needed. Two Phase III trials, OPT-80-003 and OPT-80-004, showed that oral fidaxomicin for 10 days was noninferior compared with treatment with oral vancomycin among adult patients with toxin-positive C. difficile-associated diarrhea (CDAD). Furthermore, fidaxomicin was associated with a lower rate of recurrence of CDAD within 4 weeks of completion of therapy. The safety and tolerability of fidaxomicin was consistent with earlier studies and established that fidaxomicin is an efficacious and well-tolerated treatment option for CDAD. Despite these potential advantages, the cost-effectiveness of this expensive agent remains poorly understood.

  16. Radiolabelling of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.G.; Neves, Nicoli M.J. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L. [Ouro Preto Univ., MG (Brazil). Escola de Farmacia. Lab. de Fisiologia e Bioquimica de Microorganismos; Lima, M.E. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Bioquimica e Imunologia; Nicoli, J.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Microbiologia

    1999-11-01

    Binding of cholera toxin to ganglioside receptors of enterocyte microvilli catalyzes the activation of adenylate cyclase causing a rise in cAMP which final result is a copious diarrhea. Saccharomyces boulardii, a nonpathogenic yeast has been used to prevent diarrhea. Although the antidiarrheic properties of S. boulardii are widely recognized, this yeast has been used on empirical basis, and the mechanism of this protective effect is unknown. The addition of cholera toxin to S. boulardii induces the raising of cAMP that triggers the activation of neutral trehalase. This suggests that toxin specifically binding to cells, is internalized and active the protein phosphorylation cascade. Our objective is labeling the cholera toxin to verify the presence of binding sites on yeast cell surfaces for the cholera toxin. Cholera toxin was radiolabelled with Na {sup 125} I by a chloramine-T method modified from Cuatrecasas and Griffiths et alii. The {sup 125} I-Cholera toxin showed a specific radioactivity at about 1000 cpm/fmol toxin. Biological activity of labeled cholera toxin measured by trehalase activation was similar to the native toxin. (author) 5 refs., 3 figs.; e-mail: nevesmj at urano.cdtn.br

  17. Radiolabelling of cholera toxin

    International Nuclear Information System (INIS)

    Santos, R.G.; Neves, Nicoli M.J.; Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L.; Lima, M.E. de; Nicoli, J.R.

    1999-01-01

    Binding of cholera toxin to ganglioside receptors of enterocyte microvilli catalyzes the activation of adenylate cyclase causing a rise in cAMP which final result is a copious diarrhea. Saccharomyces boulardii, a nonpathogenic yeast has been used to prevent diarrhea. Although the antidiarrheic properties of S. boulardii are widely recognized, this yeast has been used on empirical basis, and the mechanism of this protective effect is unknown. The addition of cholera toxin to S. boulardii induces the raising of cAMP that triggers the activation of neutral trehalase. This suggests that toxin specifically binding to cells, is internalized and active the protein phosphorylation cascade. Our objective is labeling the cholera toxin to verify the presence of binding sites on yeast cell surfaces for the cholera toxin. Cholera toxin was radiolabelled with Na 125 I by a chloramine-T method modified from Cuatrecasas and Griffiths et alii. The 125 I-Cholera toxin showed a specific radioactivity at about 1000 cpm/fmol toxin. Biological activity of labeled cholera toxin measured by trehalase activation was similar to the native toxin. (author)

  18. Severity and frequency of community-onset Clostridium difficile infection on an Australian tertiary referral hospital campus.

    Science.gov (United States)

    Clohessy, Penny; Merif, Juan; Post, Jeffrey John

    2014-12-01

    Clostridium difficile infection (CDI) is increasingly being found in populations without traditional risk factors. We compared the relative frequency, risk factors, severity, and outcomes of community-onset CDI with hospital-acquired infection. This was a retrospective, observational study of CDI at a tertiary hospital campus in Sydney, Australia. Patients aged 15 years and older with a first episode of CDI from January 1 to December 31, 2011 were included. CDI was defined as the presence of diarrhoea with a positive enzyme immunoassay in conjunction with a positive cell cytotoxicity assay, toxin culture, or organism culture. Main outcome measures were onset of infection (hospital or community), risk factors, markers of severity, and outcomes for the two groups. One hundred and twenty-nine cases of CDI infection were identified, of which 38 (29%) were community-onset. The community-onset infection group were less likely to have a recent history of antibiotic use (66% vs. 98%; pinfection group. Markers of severity and outcomes were similar in the two groups, with an overall mortality of 9%. Community-onset CDI accounts for a large proportion of C. difficile infections and has a similar potential for severe disease as hospital-acquired infection. Using a history of previous antibiotic use, proton pump inhibitor use, or recent hospitalization to predict cases is unreliable. We recommend that patients with diarrhoea being investigated in emergency departments and community practice are tested for Clostridium difficile infection. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Clinical and microbiologic characteristics of tcdA-negative variant clostridium difficile infections

    Directory of Open Access Journals (Sweden)

    Kim Jieun

    2012-05-01

    Full Text Available Abstract Background The tcdA-negative variant (A-B+ of Clostridium difficile is prevalent in East Asian countries. However, the risk factors and clinical characteristics of A-B+C. difficile infections (CDI are not clearly documented. The objective of this study was to investigate these characteristics. Methods From September 2008 through January 2010, the clinical characteristics, medication history and treatment outcomes of CDI patients were recorded prospectively. Toxin characterization and antibiotic susceptibility tests were performed on stool isolates of C. difficile. Results During the study period, we identified 22 cases of CDI caused by tcdA-negative tcdB-positive (A-B+ strains and 105 cases caused by tcdA-positive tcdB-positive (A+B+ strains. There was no significant difference in disease severity or clinical characteristics between the two groups. Previous use of clindamycin and young age were identified as significant risk factors for the acquisition of A-B+ CDI (OR = 4.738, 95% CI 1.48–15.157, p = 0.009 and OR = 0.966, 95% CI 0.935–0.998, p = 0.038, respectively in logistic regression. Rates of resistance to clindamycin were 100% and 69.6% in the A-B+ and A+B+ isolates, respectively (p = 0.006, and the ermB gene was identified in 17 of 21 A-B+ isolates (81%. Resistance to moxifloxacin was also more frequent in the A-B+ than in the A+B+ isolates (95.2% vs. 63.7%, p = 0.004. Conclusions The clinical course of A-B+ CDI is not different from that of A+B+ CDI. Clindamycin use is a significant risk factor for the acquisition of tcdA-negative variant strains.

  20. In silico analysis of antibiotic-induced Clostridium difficile infection: Remediation techniques and biological adaptations.

    Science.gov (United States)

    Jones, Eric W; Carlson, Jean M

    2018-02-01

    In this paper we study antibiotic-induced C. difficile infection (CDI), caused by the toxin-producing C. difficile (CD), and implement clinically-inspired simulated treatments in a computational framework that synthesizes a generalized Lotka-Volterra (gLV) model with SIR modeling techniques. The gLV model uses parameters derived from an experimental mouse model, in which the mice are administered antibiotics and subsequently dosed with CD. We numerically identify which of the experimentally measured initial conditions are vulnerable to CD colonization, then formalize the notion of CD susceptibility analytically. We simulate fecal transplantation, a clinically successful treatment for CDI, and discover that both the transplant timing and transplant donor are relevant to the the efficacy of the treatment, a result which has clinical implications. We incorporate two nongeneric yet dangerous attributes of CD into the gLV model, sporulation and antibiotic-resistant mutation, and for each identify relevant SIR techniques that describe the desired attribute. Finally, we rely on the results of our framework to analyze an experimental study of fecal transplants in mice, and are able to explain observed experimental results, validate our simulated results, and suggest model-motivated experiments.

  1. Clostridium difficile infection among immunocompromised patients in Rio de Janeiro, Brazil and detection of moxifloxacin resistance in a ribotype 014 strain.

    Science.gov (United States)

    Secco, Danielle Angst; Balassiano, Ilana Teruszkin; Boente, Renata Ferreira; Miranda, Karla Rodrigues; Brazier, Jon; Hall, Val; dos Santos-Filho, Joaquim; Lobo, Leandro Araujo; Nouér, Simone Aranha; Domingues, Regina Maria Cavalcanti Pilotto

    2014-08-01

    Clostridium difficile is a Gram-positive spore forming anaerobic bacterium, often associated with nosocomial diarrhea and pseudomembranous colitis. The acquisition of this organism occurs primarily in hospitals through accidental ingestion of spores, and its establishment and proliferation in the colon results from the removal of members of the normal intestinal flora during or after antibiotic therapy. In this study, stool samples from patients admitted to the University Hospital Clementino Fraga Filho (HUCCF/UFRJ) were screened for C. difficile toxins with an ELISA test and cultured with standard techniques for C. difficile isolation. A total of 74 stool samples were collected from patients undergoing antibiotic therapy between August 2009 and November 2010, only two (2.7%) were positive in the ELISA test and culture. A third isolate was obtained from a negative ELISA test sample. All cases of CDI were identified in patients with acute lymphoid or myeloid leukemia. Genotypic and phenotypic characterization showed that all strains carried toxins A and B genes, and belonged to PCR-ribotypes 014, 043 and 046. The isolated strains were sensitive to metronidazole and vancomycin, and resistant to ciprofloxacin and levofloxacin. Resistance to moxifloxacin, was present in the strain from PCR-ribotype 014, that showed an amino acid substitution in gyrB gene (Asp 426 → Asn). This is the first time that this mutation in a PCR-ribotype 014 strain has been described in Brazil. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. [Intoxication of botulinum toxin].

    Science.gov (United States)

    Chudzicka, Aleksandra

    2015-09-01

    Botulinum toxin is an egzotoxin produced by Gram positive bacteria Clostridium botulinum. It is among the most potent toxins known. The 3 main clinical presentations of botulism are as follows: foodborne botulism, infant botulism and wound botulism. The main symptom of intoxication is flat muscles paralysis. The treatment is supportive care and administration of antitoxin. In prevention the correct preparing of canned food is most important. Botulinum toxin is accepted as a biological weapon. © 2015 MEDPRESS.

  3. Clinical update for the diagnosis and treatment of Clostridium difficile infection

    Science.gov (United States)

    IV, Edward C Oldfield; III, Edward C Oldfield; Johnson, David A

    2014-01-01

    Clostridium difficile infection (CDI) presents a rapidly evolving challenge in the battle against hospital-acquired infections. Recent advances in CDI diagnosis and management include rapid changes in diagnostic approach with the introduction of newer tests, such as detection of glutamate dehydrogenase in stool and polymerase chain reaction to detect the gene for toxin production, which will soon revolutionize the diagnostic approach to CDI. New medications and multiple medical society guidelines have introduced changing concepts in the definitions of severity of CDI and the choice of therapeutic agents, while rapid expansion of data on the efficacy of fecal microbiota transplantation heralds a revolutionary change in the management of patients suffering multiple relapses of CDI. Through a comprehensive review of current medical literature, this article aims to offer an intensive review of the current state of CDI diagnosis, discuss the strengths and limitations of available laboratory tests, compare both current and future treatments options and offer recommendations for best practice strategies. PMID:24729930

  4. Non-canonical CRL4A/4B(CDT2 interacts with RAD18 to modulate post replication repair and cell survival.

    Directory of Open Access Journals (Sweden)

    Sarah Sertic

    Full Text Available The Cullin-4(CDT2 E3 ubiquitin ligase plays an essential role in DNA replication origin licensing directing degradation of several licensing factors at the G1/S transition in order to prevent DNA re-replication. Recently a RAD18-independent role of Cullin-4(CDT2 in PCNA monoubiquitylation has been proposed. In an effort to better understand the function of Cullin-4(CDT2 E3 ubiquitin ligase in mammalian Post-Replication Repair during an unperturbed S-phase, we show that down-regulation of Cullin-4(CDT2 leads to two distinguishable independent phenotypes in human cells that unveil at least two independent roles of Cullin-4(CDT2 in S-phase. Apart from the re-replication preventing activity, we identified a non-canonical Cullin-4(CDT2 complex, containing both CUL4A and CUL4B, associated to the COP9 signalosome, that controls a RAD18-dependent damage avoidance pathway essential during an unperturbed S-phase. Indeed, we show that the non-canonical Cullin-4A/4B(CDT2 complex binds to RAD18 and it is required to modulate RAD18 protein levels onto chromatin and the consequent dynamics of PCNA monoubiquitylation during a normal S-phase. This function prevents replication stress, ATR hyper-signaling and, ultimately, apoptosis. A very similar PRR regulatory mechanism has been recently described for Spartan. Our findings uncover a finely regulated process in mammalian cells involving Post-Replication Repair factors, COP9 signalosome and a non-canonical Cullin4-based E3 ligase which is essential to tolerate spontaneous damage and for cell survival during physiological DNA replication.

  5. Use of finger-prick dried blood spots (fpDBS) and capillary electrophoresis for carbohydrate deficient transferrin (CDT) screening in forensic toxicology.

    Science.gov (United States)

    Bertaso, Anna; Sorio, Daniela; Vandoros, Anthula; De Palo, Elio F; Bortolotti, Federica; Tagliaro, Franco

    2016-10-01

    Continued progress in chronic alcohol abuse investigation requires the development of less invasive procedures for screening purposes. The application of finger-prick and related dried blood spots (fpDBS) for carbohydrate deficient transferrin (CDT) detection appears suitable for this aim. Therefore, the goal of this project was to develop a screening method for CDT using fpDBS with CZE analysis. Blood samples prepared by finger-prick were placed on DBS cards and left to air dry; each dried fpDBS disc was shredded into small pieces and suspended in acid solution (60 μL of HCl 120 mmol/L). After centrifugation (10 min at 1500 × g), the collected sample was adjusted to pH 3.5. After an overnight incubation, the pH was neutralised and an iron rich solution was added. After 1 h, CZE analysis was carried out. A group of 47 individuals was studied. Parallel serum samples were collected from each investigated subject and the %CDT for each sample was measured using HPLC and CZE techniques. The fpDBS transferrin sialo isoform electropherograms were similar to those obtained with serum. Moreover, fpDBS CZE CDT percentage levels demonstrated significant statistical correlation with those obtained from serum for both HPLC and CZE %CDT (p < 0.01; r 2 = 0.8913 and 0.8976, respectively), with %CDT from 0.8 to 13.7% for fpDBS and from 0.7 to 12.7% for serum. The newly developed fpDBS procedure for CDT analysis provides a simple and inexpensive tool for use in population screening. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Epidemiology, risk factors, and outcome of Clostridium difficile infection in heart and heart-lung transplant recipients.

    Science.gov (United States)

    Bruminhent, Jackrapong; Cawcutt, Kelly A; Thongprayoon, Charat; Petterson, Tanya M; Kremers, Walter K; Razonable, Raymund R

    2017-06-01

    Clostridium difficile is a major cause of diarrhea in thoracic organ transplant recipients. We investigated the epidemiology, risk factors, and outcome of Clostridium difficile infection (CDI) in heart and heart-lung transplant (HT) recipients. This is a retrospective study from 2004 to 2013. CDI was defined by diarrhea and a positive toxigenic C. difficile in stool measured by toxin enzyme immunoassay (2004-2006) or polymerase chain reaction (2007-2013). Cox proportional hazards regression was used to model the association of risk factors with time to CDI and survival with CDI following transplantation. There were 254 HT recipients, with a median age of 53 years (IQR, 45-60); 34% were female. During the median follow-up of 3.1 years (IQR, 1.3-6.1), 22 (8.7%) patients developed CDI. In multivariable analysis, risk factors for CDI were combined heart-lung transplant (HR 4.70; 95% CI, 1.30-17.01 [P=.02]) and retransplantation (HR 7.19; 95% CI, 1.61-32.12 [P=.01]). Acute cellular rejection was associated with a lower risk of CDI (HR 0.34; 95% CI, 0.11-0.94 [P=.04]). CDI was found to be an independent risk factor for mortality (HR 7.66; 95% CI, 3.41-17.21 [PClostridium difficile infection after HT is more common among patients with combined heart-lung and those undergoing retransplantation. CDI was associated with a higher risk of mortality in HT recipients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Diverticular disease of the colon does not increase risk of repeat C. difficile infection.

    Science.gov (United States)

    Feuerstadt, Paul; Das, Rohit; Brandt, Lawrence J

    2013-01-01

    Studies have suggested that colonic diverticulosis might increase the likelihood of repeat Clostridium difficile infection (CDI). Our study was designed to compare rates of repeat infection in patients with and without colon diverticula. Patients who had a positive C. difficile toxin assay and colonoscopic evidence of diverticulosis were classified as CDI and diverticulosis (CDI-D), whereas those with a positive toxin assay but no such colonoscopic evidence were classified as CDI and no diverticulosis (CDI-ND). Various clinical and epidemiologic factors were recorded for each patient. Primary outcomes were "relapse" (repeat CDI within 3 mo of initial infection) and "recurrent" infection (repeat CDI≥3 mo after initial infection). Secondary outcomes 30 days after diagnosis were mortality, intensive care unit transfer, and continuous hospitalization. A total of 128 patients were classified as CDI-D, whereas 137 had CDI-ND. There were no significant differences between CDI-D and CDI-ND when comparing frequencies of repeat infection and its subclassifications, relapse or recurrence. There were, however, statistical associations seen between diverticulosis of the ascending colon and increased recurrence rates [hazard ratio (HR): 1.4±0.38, Pdiverticular disease of the descending (HR: 0.40±0.46, Pcolon (HR: 0.39±0.49, Pcolon association is limited by a small patient population. There were no significant differences in any of the 30-day outcomes including intensive care unit requirement, hospitalization stay, or mortality. Patients with diverticular disease of the colon are not at increased risk of repeat CDI.

  8. Conserved oligopeptide permeases modulate sporulation initiation in Clostridium difficile.

    Science.gov (United States)

    Edwards, Adrianne N; Nawrocki, Kathryn L; McBride, Shonna M

    2014-10-01

    The anaerobic gastrointestinal pathogen Clostridium difficile must form a metabolically dormant spore to survive in oxygenic environments and be transmitted from host to host. The regulatory factors by which C. difficile initiates and controls the early stages of sporulation in C. difficile are not highly conserved in other Clostridium or Bacillus species. Here, we investigated the role of two conserved oligopeptide permeases, Opp and App, in the regulation of sporulation in C. difficile. These permeases are known to positively affect sporulation in Bacillus species through the import of sporulation-specific quorum-sensing peptides. In contrast to other spore-forming bacteria, we discovered that inactivating these permeases in C. difficile resulted in the earlier expression of early sporulation genes and increased sporulation in vitro. Furthermore, disruption of opp and app resulted in greater virulence and increased the amounts of spores recovered from feces in the hamster model of C. difficile infection. Our data suggest that Opp and App indirectly inhibit sporulation, likely through the activities of the transcriptional regulator SinR and its inhibitor, SinI. Taken together, these results indicate that the Opp and App transporters serve a different function in controlling sporulation and virulence in C. difficile than in Bacillus subtilis and suggest that nutrient availability plays a significant role in pathogenesis and sporulation in vivo. This study suggests a link between the nutritional status of the environment and sporulation initiation in C. difficile. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. Management of Clostridium difficile diarrhoea in District General ...

    African Journals Online (AJOL)

    ... four cases of Clostridium difficile in our hospital over duration of three months. We looked into the demographic features of the patient population and compliance with the Trust guidelines for the management of the diarrhoea. Keywords:Diarrhoea, Clostridium difficile, Management. Internet Journal of Medical Update Vol.

  10. Duodenal infusion of donor feces for recurrent Clostridium difficile

    NARCIS (Netherlands)

    van Nood, Els; Vrieze, Anne; Nieuwdorp, Max; Fuentes, Susana; Zoetendal, Erwin G.; de Vos, Willem M.; Visser, Caroline E.; Kuijper, Ed J.; Bartelsman, Joep F. W. M.; Tijssen, Jan G. P.; Speelman, Peter; Dijkgraaf, Marcel G. W.; Keller, Josbert J.

    2013-01-01

    Recurrent Clostridium difficile infection is difficult to treat, and failure rates for antibiotic therapy are high. We studied the effect of duodenal infusion of donor feces in patients with recurrent C. difficile infection. We randomly assigned patients to receive one of three therapies: an initial

  11. Muricholic acids inhibit Clostridium difficile spore germination and growth.

    Directory of Open Access Journals (Sweden)

    Michael B Francis

    Full Text Available Infections caused by Clostridium difficile have increased steadily over the past several years. While studies on C. difficile virulence and physiology have been hindered, in the past, by lack of genetic approaches and suitable animal models, newly developed technologies and animal models allow these processes to be studied in detail. One such advance is the generation of a mouse-model of C. difficile infection. The development of this system is a major step forward in analyzing the genetic requirements for colonization and infection. While important, it is equally as important in understanding what differences exist between mice and humans. One of these differences is the natural bile acid composition. Bile acid-mediated spore germination is an important step in C. difficile colonization. Mice produce several different bile acids that are not found in humans. These muricholic acids have the potential to impact C. difficile spore germination. Here we find that the three muricholic acids (α-muricholic acid, β-muricholic acid and ω-muricholic acid inhibit C. difficile spore germination and can impact the growth of vegetative cells. These results highlight an important difference between humans and mice and may have an impact on C. difficile virulence in the mouse-model of C. difficile infection.

  12. Clostridium difficile: A healthcare-associated infection of unknown ...

    African Journals Online (AJOL)

    Clostridium difficile: A healthcare-associated infection of unknown significance in adults in sub-Saharan Africa. ... Abstract. Background: Clostridium difficile infection (CDI) causes a high burden of disease in high-resource healthcare systems, with significant morbidity, mortality, and financial implications. CDI is a ...

  13. [Clostridium difficile infection: epidemiology, disease burden and therapy].

    Science.gov (United States)

    Gulácsi, László; Kertész, Adrienne; Kopcsóné Németh, Irén; Banai, János; Ludwig, Endre; Prinz, Gyula; Reményi, Péter; Strbák, Bálint; Zsoldiné Urbán, Edit; Baji, Petra; Péntek, Márta; Brodszky, Valentin

    2013-07-28

    C. difficile causes 25 percent of the antibiotic associated infectious nosocomial diarrhoeas. C. difficile infection is a high-priority problem of public health in each country. The available literature of C. difficile infection's epidemiology and disease burden is limited. Review of the epidemiology, including seasonality and the risk of recurrences, of the disease burden and of the therapy of C. difficile infection. Review of the international and Hungarian literature in MEDLINE database using PubMed up to and including 20th of March, 2012. The incidence of nosocomial C. difficile associated diarrhoea is 4.1/10 000 patient day. The seasonality of C. difficile infection is unproved. 20 percent of the patients have recurrence after metronidazole or vancomycin treatment, and each recurrence increases the chance of a further one. The cost of C. difficile infection is between 130 and 500 thousand HUF (430 € and 1665 €) in Hungary. The importance of C. difficile infection in public health and the associated disease burden are significant. The available data in Hungary are limited, further studies in epidemiology and health economics are required.

  14. Clostridium difficile colitis in patients undergoing lumbar spine surgery.

    Science.gov (United States)

    Skovrlj, Branko; Guzman, Javier Z; Silvestre, Jason; Al Maaieh, Motasem; Qureshi, Sheeraz A

    2014-09-01

    Retrospective database analysis. To investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after lumbar spine surgery. C. difficile colitis is reportedly increasing in hospitalized patients and can have a negative impact on patient outcomes. No data exist on estimates of C. difficile infection rates and its consequences on patient outcomes and health care resources among patients undergoing lumbar spine surgery. The Nationwide Inpatient Sample was examined from 2002 to 2011. Patients were included for study based on International Classification of Diseases, Ninth Revision, Clinical Modification, procedural codes for lumbar spine surgery for degenerative diagnoses. Baseline patient characteristics were determined and multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. The incidence of C. difficile infection in patients undergoing lumbar spine surgery is 0.11%. At baseline, patients infected with C. difficile were significantly older (65.4 yr vs. 58.9 yr, Pinfection. Small hospital size was associated with decreased odds (odds ratio [OR], 0.5; Pinfection. Uninsured (OR, 1.62; Pinfection. C. difficile increased hospital length of stay by 8 days (Pdifficile infection after lumbar spine surgery carries a 36.4-fold increase in mortality and costs approximately $10,658,646 per year to manage. These data suggest that great care should be taken to avoid C. difficile colitis in patients undergoing lumbar spine surgery because it is associated with longer hospital stays, greater overall costs, and increased inpatient mortality. 3.

  15. Update of treatment algorithms for Clostridium difficile infection

    NARCIS (Netherlands)

    Ooijevaar, R. E.; van Beurden, Y. H.; Terveer, E. M.; Goorhuis, A.; Bauer, M. P.; Keller, J. J.; Mulder, C. J. J.; Kuijper, E. J.

    2018-01-01

    Clostridium difficile is the leading cause of antibiotic-associated diarrhea, both in healthcare facilities and the community. The recurrence rate of C. difficile infection (CDI) remains high, up to 20%. Since the publication of the ESCMID guidance document on CDI treatment in 2014, new therapeutic

  16. Application of a high throughput method of biomarker discovery to improvement of the EarlyCDT(®-Lung Test.

    Directory of Open Access Journals (Sweden)

    Isabel K Macdonald

    Full Text Available BACKGROUND: The National Lung Screening Trial showed that CT screening for lung cancer led to a 20% reduction in mortality. However, CT screening has a number of disadvantages including low specificity. A validated autoantibody assay is available commercially (EarlyCDT®-Lung to aid in the early detection of lung cancer and risk stratification in patients with pulmonary nodules detected by CT. Recent advances in high throughput (HTP cloning and expression methods have been developed into a discovery pipeline to identify biomarkers that detect autoantibodies. The aim of this study was to demonstrate the successful clinical application of this strategy to add to the EarlyCDT-Lung panel in order to improve its sensitivity and specificity (and hence positive predictive value, (PPV. METHODS AND FINDINGS: Serum from two matched independent cohorts of lung cancer patients were used (n = 100 and n = 165. Sixty nine proteins were initially screened on an abridged HTP version of the autoantibody ELISA using protein prepared on small scale by a HTP expression and purification screen. Promising leads were produced in shake flask culture and tested on the full assay. These results were analyzed in combination with those from the EarlyCDT-Lung panel in order to provide a set of re-optimized cut-offs. Five proteins that still displayed cancer/normal differentiation were tested for reproducibility and validation on a second batch of protein and a separate patient cohort. Addition of these proteins resulted in an improvement in the sensitivity and specificity of the test from 38% and 86% to 49% and 93% respectively (PPV improvement from 1 in 16 to 1 in 7. CONCLUSION: This is a practical example of the value of investing resources to develop a HTP technology. Such technology may lead to improvement in the clinical utility of the EarlyCDT--Lung test, and so further aid the early detection of lung cancer.

  17. Identification and characterization of the surface proteins of Clostridium difficile

    International Nuclear Information System (INIS)

    Dailey, D.C.

    1988-01-01

    Several clostridial proteins were detected on the clostridial cell surface by sensitive radioiodination techniques. Two major proteins and six minor proteins comprised the radioiodinated proteins on the clostridial cell surface. Cellular fractionation of surface radiolabeled C. difficile determined that the radioiodinated proteins were found in the cell wall fraction of C. difficile and surprisingly were also present in the clostridial membrane. Furthermore, an interesting phenomenon of disulfide-crosslinking of the cell surface proteins of C. difficile was observed. Disulfide-linked protein complexes were found in both the membrane and cell wall fractions. In addition, the cell surface proteins of C. difficile were found to be released into the culture medium. In attempts to further characterize the clostridial proteins recombinant DNA techniques were employed. In addition, the role of the clostridial cell surface proteins in the interactions of C. difficile with human PMNs was also investigated

  18. Clostridium difficile infection: Evolution, phylogeny and molecular epidemiology.

    Science.gov (United States)

    Elliott, Briony; Androga, Grace O; Knight, Daniel R; Riley, Thomas V

    2017-04-01

    Over the recent decades, Clostridium difficile infection (CDI) has emerged as a global public health threat. Despite growing attention, C. difficile remains a poorly understood pathogen, however, the exquisite sensitivity offered by next generation sequencing (NGS) technology has enabled analysis of the genome of C. difficile, giving us access to massive genomic data on factors such as virulence, evolution, and genetic relatedness within C. difficile groups. NGS has also demonstrated excellence in investigations of outbreaks and disease transmission, in both small and large-scale applications. This review summarizes the molecular epidemiology, evolution, and phylogeny of C. difficile, one of the most important pathogens worldwide in the current antibiotic resistance era. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Presence of Clostridium difficile in poultry and poultry meat in Egypt

    OpenAIRE

    Abdel-Glil, Mostafa Y.; Thomas, Prasad; Schmoock, Gernot; Abou-El-Azm, Kamel; Wieler, Lothar H.; Neubauer, Heinrich; Seyboldt, Christian

    2018-01-01

    C. difficile has been recognized as a potential zoonotic agent encouraging investigations of C. difficile prevalence and ribotypes in animals. Here we report the prevalence and diversity of Egyptian C. difficile in I) samples from healthy poultry (n = 50), II) samples from diseased poultry (n = 54), and III) poultry meat (n = 150). Thirteen isolates were obtained from seven healthy and five diseased animals, but no C. difficile was cultured from poultry meat. The isolated C. difficile strains...

  20. Enhanced surveillance of Clostridium difficile infection occurring outside hospital, England, 2011 to 2013.

    Science.gov (United States)

    Fawley, Warren N; Davies, Kerrie A; Morris, Trefor; Parnell, Peter; Howe, Robin; Wilcox, Mark H

    2016-07-21

    There are limited national epidemiological data for community-associated (CA)-Clostridium difficile infections (CDIs). Between March 2011 and March 2013, laboratories in England submitted to the Clostridium difficile Ribotyping Network (CDRN) up to 10 diarrhoeal faecal samples from successive patients with CA-CDI, defined here as C. difficile toxin-positive diarrhoea commencing outside hospital (or less than 48 hours after hospital admission), including those cases associated with community-based residential care, with no discharge from hospital within the previous 12 weeks. Patient demographics and C. difficile PCR ribotypes were compared for CA-CDIs in our study and presumed healthcare-associated (HA) CDIs via CDRN. Ribotype diversity indices, ranking and relative prevalences were very similar in CA- vs HA-CDIs, although ribotypes 002 (p ≤ 0.0001),020 (p = 0.009) and 056 (p < 0.0001) predominated in CA-CDIs; ribotype 027 (p = 0.01) predominated in HA-CDIs. Epidemic ribotypes 027 and 078 predominated in institutional residents with CDI (including care/nursing homes) compared with people with CDI living at home. Ribotype diversity decreased with increasing age in HA-CDIs, but not in CA-CDIs. Ribotype 078 CA-CDIs were significantly more common in elderly people (3.4% (6/174) vs 8.7% (45/519) in those aged < 65 and ≥ 65 years, respectively; p = 0.019). No antibiotics were prescribed in the previous four weeks in about twofold more CA-CDI vs HAs (38.6% (129/334) vs 20.3% (1,226/6,028); p < 0.0001). We found very similar ribotype distributions in CA- and HA-CDIs, although a few ribotypes significantly predominated in one setting. These national data emphasise the close interplay between, and likely common reservoirs for, CDIs, particularly when epidemic strains are not dominant. This article is copyright of The Authors, 2016.

  1. The Burden of Clostridium difficile after Cervical Spine Surgery.

    Science.gov (United States)

    Guzman, Javier Z; Skovrlj, Branko; Rothenberg, Edward S; Lu, Young; McAnany, Steven; Cho, Samuel K; Hecht, Andrew C; Qureshi, Sheeraz A

    2016-06-01

    Study Design Retrospective database analysis. Objective The purpose of this study is to investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after cervical spine surgery. Methods A total of 1,602,130 cervical spine surgeries from the Nationwide Inpatient Sample database from 2002 to 2011 were included. Patients were included for study based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for cervical spine surgery for degenerative spine diagnoses. Baseline patient characteristics were determined. Multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. Results Incidence of C. difficile infection in postoperative cervical spine surgery hospitalizations is 0.08%, significantly increased since 2002 (p difficile infection were significantly increased in patients with comorbidities such as congestive heart failure, renal failure, and perivascular disease. Circumferential cervical fusion (odds ratio [OR] = 2.93, p difficile infection after degenerative cervical spine surgery. C. difficile infection after cervical spine surgery results in extended length of stay (p costs (p difficile after cervical spine surgery is nearly 8% versus 0.19% otherwise (p difficile to be a significant predictor of inpatient mortality (OR = 3.99, p difficile increases the risk of in-hospital mortality and costs approximately $6,830,695 per year to manage in patients undergoing elective cervical spine surgery. Patients with comorbidities such as renal failure or congestive heart failure have increased probability of developing infection after surgery. Accepted antibiotic guidelines in this population must be followed to decrease the risk of developing postoperative C. difficile colitis.

  2. PIP degron proteins, substrates of CRL4Cdt2, and not PIP boxes, interfere with DNA polymerase η and κ focus formation on UV damage.

    Science.gov (United States)

    Tsanov, Nikolay; Kermi, Chames; Coulombe, Philippe; Van der Laan, Siem; Hodroj, Dana; Maiorano, Domenico

    2014-04-01

    Proliferating cell nuclear antigen (PCNA) is a well-known scaffold for many DNA replication and repair proteins, but how the switch between partners is regulated is currently unclear. Interaction with PCNA occurs via a domain known as a PCNA-Interacting Protein motif (PIP box). More recently, an additional specialized PIP box has been described, the « PIP degron », that targets PCNA-interacting proteins for proteasomal degradation via the E3 ubiquitin ligase CRL4(Cdt2). Here we provide evidence that CRL4(Cdt2)-dependent degradation of PIP degron proteins plays a role in the switch of PCNA partners during the DNA damage response by facilitating accumulation of translesion synthesis DNA polymerases into nuclear foci. We show that expression of a nondegradable PIP degron (Cdt1) impairs both Pol η and Pol κ focus formation on ultraviolet irradiation and reduces cell viability, while canonical PIP box-containing proteins have no effect. Furthermore, we identify PIP degron-containing peptides from several substrates of CRL4(Cdt2) as efficient inhibitors of Pol η foci formation. By site-directed mutagenesis we show that inhibition depends on a conserved threonine residue that confers high affinity for PCNA-binding. Altogether these findings reveal an important regulative role for the CRL4(Cdt2) pathway in the switch of PCNA partners on DNA damage.

  3. Clostridium difficile Infection and Patient-Specific Antimicrobial Resistance Testing Reveals a High Metronidazole Resistance Rate.

    Science.gov (United States)

    Barkin, Jodie A; Sussman, Daniel A; Fifadara, Nimita; Barkin, Jamie S

    2017-04-01

    Clostridium difficile (CD) infection (CDI) causes marked morbidity and mortality, accounting for large healthcare expenditures annually. Current CDI treatment guidelines focus on clinical markers of patient severity to determine the preferred antibiotic regimen of metronidazole versus vancomycin. The antimicrobial resistance patterns for patients with CD are currently unknown. The aim of this study was to define the antimicrobial resistance patterns for CD. This study included all patients with stools sent for CD testing to a private laboratory (DRG Laboratory, Alpharetta, Georgia) in a 6-month period from across the USA. Patient data was de-identified, with only age, gender, and zip-code available per laboratory protocol. All samples underwent PCR testing followed by hybridization for CD toxin regions A and B. Only patients with CD-positive PCR were analyzed. Antimicrobial resistance testing using stool genomic DNA evaluated presence of imidazole- and vancomycin-resistant genes using multiplex PCR gene detection. Of 2743, 288 (10.5%) stool samples were positive for CD. Six were excluded per protocol. Of 282, 193 (69.4%) were women, and average age was 49.4 ± 18.7 years. Of 282, 62 were PCR positive for toxins A and B, 160 for toxin A positive alone, and 60 for toxin B positive alone. Antimicrobial resistance testing revealed 134/282 (47.5%) patients resistant to imidazole, 17 (6.1%) resistant to vancomycin, and 9 (3.2%) resistant to imidazole and vancomycin. CD-positive patients with presence of imidazole-resistant genes from stool DNA extract was a common phenomenon, while vancomycin resistance was uncommon. Similar to treatment of other infections, antimicrobial resistance testing should play a role in CDI clinical decision-making algorithms to enable more expedited and cost-effective delivery of patient care.

  4. [Characteristics of Clostridium difficile infection in a high complexity hospital and report of the circulation of the NAP1/027 hypervirulent strain in Colombia].

    Science.gov (United States)

    Gualtero, Sandra Milena; Abril, Lina Alejandra; Camelo, Nathalia; Sanchez, Susi Daniela; Davila, Fabián Antonio; Arias, Gerson; Silva, Edwin; Bustos, Ingrid Gissel; Josa, Diego Fernando; Torres, Isabel Cristina; Zambrano, Luis Carlos; Pareja, María José

    2017-12-01

    Clostridium difficile is the main pathogen related to healthcare-associated diarrhea and it is the cause of 20 to 30% of diarrhea cases caused by antibiotics. In Colombia and Latin America, the knowledge about the epidemiological behavior of this infection is limited. To describe the characteristics of a series of patients with C. difficile infection. We performed a descriptive case series study of patients with C. difficile infection hospitalized in the Fundación Clínica Shaio from January, 2012, to November, 2015. We analyzed 36 patients. The average age was 65 years. The risk factors associated with the infection were: previous use of antibiotics (94.4%), prior hospitalization in the last three months (66.7%) and use of proton pump inhibitors (50%). The most common comorbidities were chronic kidney disease (41.7%) and diabetes mellitus (30.6%). The most frequent symptoms were more than three loose stools per day (97.1%) and abdominal pain (42.9%). According to the severity of the disease, 44.4% of cases were classified as mild to moderate, 38.9% as severe, and 11.1% as complicated or severe. The detection of the toxin by PCR (GeneXpert) was the most common diagnostic procedure (63.8%). Global mortality during hospitalization was 8%. We identified four strains with serotype NAP1/027 and nine samples positive for binary toxin. Clostridium difficile infection should be suspected in patients with diarrhea and traditional risk factors associated with this disease. We report the circulation of the hypervirulent strain serotype NAP1/027 in Colombia, which should be countered with epidemiological surveillance and a prompt diagnosis.

  5. The monoclonal antitoxin antibodies (actoxumab-bezlotoxumab treatment facilitates normalization of the gut microbiota of mice with Clostridium difficile infection

    Directory of Open Access Journals (Sweden)

    Mária Džunková

    2016-10-01

    Full Text Available Antibiotics have significant and long-lasting impacts on the intestinal microbiota and consequently reduce colonization resistance against Clostridium difficile infection (CDI. Standard therapy using antibiotics is associated with a high rate of disease recurrence, highlighting the need for novel treatment strategies that target toxins, the major virulence factors, rather than the organism itself. Human monoclonal antibodies MK-3415A (actoxumab-bezlotoxumab to C. difficile toxin A and toxin B, as an emerging non-antibiotic approach, significantly reduced the recurrence of CDI in animal models and human clinical trials. Although the main mechanism of protection is through direct neutralization of the toxins, the impact of MK-3415A on gut microbiota and its restoration has not been examined. Using a CDI murine model, we compared the bacterial diversity of the gut microbiome of mice under different treatments including MK-3415A, vancomycin or vancomycin combined with MK-3415A, sampled longitudinally. Here we showed that C. difficile infection resulted in the prevalence of Enterobacter species. 60% of mice in the vehicle group died after two days and their microbiome was almost exclusively formed by Enterobacter. MK-3415A treatment resulted in lower Enterobacter levels and restoration of Blautia, Akkermansia and Lactobacillus which were the core components of the original microbiota. Vancomycin treatment led to significantly lower survival rate than the combo treatment of MK-3415A and vancomycin. Vancomycin treatment decreased bacterial diversity with predominant Enterobacter and Akkermansia, while Staphylococcus expanded after vancomycin treatment was terminated. In contrast, mice treated by vancomycin combined with MK-3415A also experienced decreased bacterial diversity during vancomycin treatment. However, these animals were able to recover their initial Blautia and Lactobacillus proportions, even though episodes of Staphylococcus overgrowth were

  6. Microbiome changes associated with sustained eradication of Clostridium difficile after single faecal microbiota transplantation in children with and without inflammatory bowel disease.

    Science.gov (United States)

    Hourigan, S K; Chen, L A; Grigoryan, Z; Laroche, G; Weidner, M; Sears, C L; Oliva-Hemker, M

    2015-09-01

    Little data are available regarding the effectiveness and associated microbiome changes of faecal microbiota transplantation (FMT) for Clostridium difficile infection (CDI) in children, especially in those with inflammatory bowel disease (IBD) with presumed underlying dysbiosis. To investigate C. difficile eradication and microbiome changes with FMT in children with and without IBD. Children with a history of recurrent CDI (≥3 recurrences) underwent FMT via colonoscopy. Stool samples were collected pre-FMT and post-FMT at 2-10 weeks, 10-20 weeks and 6 months. The v4 hypervariable region of the 16S rRNA gene was sequenced. C. difficile toxin B gene polymerase chain reaction was performed. Eight children underwent FMT for CDI; five had IBD. All had resolution of CDI symptoms. All tested had eradication of C. difficile at 10-20 weeks and 6 months post-FMT. Pre-FMT patient samples had significantly decreased bacterial richness compared with donors (P = 0.01), in those with IBD (P = 0.02) and without IBD (P = 0.01). Post-FMT, bacterial diversity in patients increased. Six months post-FMT, there was no significant difference between bacterial diversity of donors and patients without IBD; however, bacterial diversity in those with IBD returned to pre-FMT baseline. Microbiome composition at 6 months in IBD-negative patients more closely approximated donor composition compared to IBD-positive patients. FMT gives sustained C. difficile eradication in children with and without IBD. FMT-restored diversity is sustained in children without IBD. In those with IBD, bacterial diversity returns to pre-FMT baseline by 6 months, suggesting IBD host-related mechanisms modify faecal microbiome diversity. © 2015 John Wiley & Sons Ltd.

  7. A new sample treatment for asialo-Tf determination with capillary electrophoresis: an added value to the analysis of CDT.

    Science.gov (United States)

    Porpiglia, Nadia Maria; De Palo, Elio Franco; Savchuk, Sergey Alexandrovich; Appolonova, Svetlana Alexandrovna; Bortolotti, Federica; Tagliaro, Franco

    2018-05-10

    The non-glycosylated glycoform of transferrin (Tf), known as asialo-Tf, was not selected (in favor of disialo-Tf) as the measurand for the standardization of carbohydrate deficient transferrin (CDT) determination because of a lower diagnostic sensitivity provided with the currently available analytical procedures for sera. However, asialo-Tf could provide an additional value to disialo-Tf in the CDT analysis employed in forensic toxicology contexts. The present work aimed at developing an easy sample preparation based on PEG precipitation in order to improve the detectability of asialo-Tf in capillary electrophoresis (CE). Equal volumes (35 μL) of serum and of 30% PEG-8000 were mixed and briefly vortexed. After centrifugation, the supernatant was iron saturated with a ferric solution (1:1, v/v). The mixture was analyzed in CE for asialo-Tf and disialo-Tf determination. PEG-8000 precipitation allowed the improvement of the baseline in the electropherograms in terms of interferences reduction particularly in the asialo-Tf migration region. The detection of asialo-Tf was possible in 89% of samples with disialo-Tf above the cut-off limit, whereas only 16% of them showed asialo-Tf by employing the traditional sample preteatment. Asialo-Tf represents an additional value to disialo-Tf as a biomarker of alcohol abuse in forensic toxicology. Copyright © 2018. Published by Elsevier B.V.

  8. Microalgal toxin(s): characteristics and importance

    African Journals Online (AJOL)

    Prokaryotic and eukaryotic microalgae produce a wide array of compounds with biological activities. These include antibiotics, algicides, toxins, pharmaceutically active compounds and plant growth regulators. Toxic microalgae, in this sense, are common only among the cyanobacteria and dinoflagellates. The microalgal ...

  9. CRISPR Diversity and Microevolution in Clostridium difficile.

    Science.gov (United States)

    Andersen, Joakim M; Shoup, Madelyn; Robinson, Cathy; Britton, Robert; Olsen, Katharina E P; Barrangou, Rodolphe

    2016-09-19

    Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. Clostridium Difficile Infection in the Nephrology Ward

    Directory of Open Access Journals (Sweden)

    Sylwia Dudzicz

    2017-11-01

    Full Text Available Clostridium difficile is currently the most frequently identified pathogen causing antibiotic-associated diarrhea and the main cause of nosocomial diarrhea. In recent years, increases incidence of infection, severe infection, recurrent infection and mortality from Clostridium difficile infection (CDI have been observed. This may be a consequence of excessive antibiotic use and spread of the hypervirulent epidemic BI/NAP1/027 strain of Clostridium difficile. The main risk factors for CDI are: antibiotic therapy, previous hospitalizations and number of comorbid conditions. Prevention of CDI mainly is focused in two directions: reducing the exposure of patients to the disease pathogen by intensifying hygiene measures, and reducing the impact of risk factors. A meta-analyses of clinical studies (observational, cohort and case control showed significantly higher risk of CDI and CDI recurrence in patients with chronic kidney disease and increased mortality risk in chronic kidney disease patients with CDI comparing those without CDI. Increased risk of CDI in patients with chronic kidney disease can be caused by: frequent antibiotic therapy associated with numerous infections resulting in intestinal microflora dysfunction, frequent hospitalizations, older age of the patients and an impaired immune system. Among preventative measures against CDI, the use of probiotics were also studied. In patients hospitalized in nephrology ward highly significant reduction of the CDI incidence was observed after the introduction of Lactobacillus plantarum 299v as CDI prophylaxis. Therefore, the use of Lactobacillus plantarum 299v seems to be a promising method of CDI prevention in chronic kidney disease patients hospitalized in nephrology ward.

  11. CRISPR Diversity and Microevolution in Clostridium difficile

    Science.gov (United States)

    Andersen, Joakim M.; Shoup, Madelyn; Robinson, Cathy; Britton, Robert; Olsen, Katharina E.P.; Barrangou, Rodolphe

    2016-01-01

    Abstract Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes. PMID:27576538

  12. C/EBPα regulates CRL4Cdt2-mediated degradation of p21 in response to UVB-induced DNA damage to control the G1/S checkpoint

    Science.gov (United States)

    Hall, Jonathan R; Bereman, Michael S; Nepomuceno, Angelito I; Thompson, Elizabeth A; Muddiman, David C; Smart, Robert C

    2014-01-01

    The bZIP transcription factor, C/EBPα is highly inducible by UVB and other DNA damaging agents in keratinocytes. C/EBPα-deficient keratinocytes fail to undergo cell cycle arrest in G1 in response to UVB-induced DNA damage and mice lacking epidermal C/EBPα are highly susceptible to UVB-induced skin cancer. The mechanism through which C/EBPα regulates the cell cycle checkpoint in response to DNA damage is unknown. Here we report untreated C/EBPα-deficient keratinocytes have normal levels of the cyclin-dependent kinase inhibitor, p21, however, UVB-treated C/EBPα-deficient keratinocytes fail to up-regulate nuclear p21 protein levels despite normal up-regulation of Cdkn1a mRNA levels. UVB-treated C/EBPα-deficient keratinocytes displayed a 4-fold decrease in nuclear p21 protein half-life due to the increased proteasomal degradation of p21 via the E3 ubiquitin ligase CRL4Cdt2. Cdt2 is the substrate recognition subunit of CRL4Cdt2 and Cdt2 mRNA and protein levels were up-regulated in UVB-treated C/EBPα-deficient keratinocytes. Knockdown of Cdt2 restored p21 protein levels in UVB-treated C/EBPα-deficient keratinocytes. Lastly, the failure to accumulate p21 in response to UVB in C/EBPα-deficient keratinocytes resulted in decreased p21 interactions with critical cell cycle regulatory proteins, increased CDK2 activity, and inappropriate entry into S-phase. These findings reveal C/EBPα regulates G1/S cell cycle arrest in response to DNA damage via the control of CRL4Cdt2 mediated degradation of p21. PMID:25483090

  13. Probiotics and prevention of Clostridium difficile infection.

    Science.gov (United States)

    Goldstein, E J C; Johnson, S J; Maziade, P-J; Evans, C T; Sniffen, J C; Millette, M; McFarland, L V

    2017-06-01

    The role of probiotics as adjunctive measures in the prevention of Clostridium difficile infection (CDI) has been controversial. However, a growing body of evidence has suggested that they have a role in primary prevention of CDI. Elements of this controversy are reviewed and the proposed mechanisms of action, the value and cost effectiveness of probiotics are addressed with a focus on three agents, Saccharomyces boulardii, Lactobacillus rhamnosus GG and the combination of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, Lactobacillus rhamnosus CLR2 (Bio-K+). Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Mortality and Clostridium difficile infection in an Australian setting.

    Science.gov (United States)

    Mitchell, Brett G; Gardner, Anne; Hiller, Janet E

    2013-10-01

    To quantify the risk of death associated with Clostridium difficile infection, in an Australian tertiary hospital. Two reviews examining Clostridium difficile infection and mortality indicate that Clostridium difficile infection is associated with increased mortality in hospitalized patients. Studies investigating the mortality of Clostridium difficile infection in settings outside of Europe and North America are required, so that the epidemiology of Clostridium difficile infection in these regions can be understood and appropriate prevention strategies made. An observational non-concurrent cohort study design was used. Data from all persons who had (exposed) and a matched sample of persons who did not have Clostridium difficile infection, for the calendar years 2007-2010, were analysed. The risk of dying within 30, 60, 90 and 180 days was compared using the two groups. Kaplan-Meier survival analysis and conditional logistic regression models were applied to the data to examine time to death and mortality risk adjusted for comorbidities using the Charlson Comorbidity Index. One hundred and fifty-eight cases of infection were identified. A statistically significant difference in all-cause mortality was identified between exposed and non-exposed groups at 60 and 180 days. In a conditional regression model, mortality in the exposed group was significantly higher at 180 days. In this Australian study, Clostridium difficile infection was associated with increased mortality. In doing so, it highlights the need for nurses to immediately instigate contact precautions for persons suspected of having Clostridium difficile infection and to facilitate a timely faecal collection for testing. Our findings support ongoing surveillance of Clostridium difficile infection and associated prevention and control activities. © 2013 Blackwell Publishing Ltd.

  15. Fate of ingested Clostridium difficile spores in mice.

    Directory of Open Access Journals (Sweden)

    Amber Howerton

    Full Text Available Clostridium difficile infection (CDI is a leading cause of antibiotic-associated diarrhea, a major nosocomial complication. The infective form of C. difficile is the spore, a dormant and resistant structure that forms under stress. Although spore germination is the first committed step in CDI onset, the temporal and spatial distribution of ingested C. difficile spores is not clearly understood. We recently reported that CamSA, a synthetic bile salt analog, inhibits C. difficile spore germination in vitro and in vivo. In this study, we took advantage of the anti-germination activity of bile salts to determine the fate of ingested C. difficile spores. We tested four different bile salts for efficacy in preventing CDI. Since CamSA was the only anti-germinant tested able to prevent signs of CDI, we characterized CamSa's in vitro stability, distribution, and cytotoxicity. We report that CamSA is stable to simulated gastrointestinal (GI environments, but will be degraded by members of the natural microbiota found in a healthy gut. Our data suggest that CamSA will not be systemically available, but instead will be localized to the GI tract. Since in vitro pharmacological parameters were acceptable, CamSA was used to probe the mouse model of CDI. By varying the timing of CamSA dosage, we estimated that C. difficile spores germinated and established infection less than 10 hours after ingestion. We also showed that ingested C. difficile spores rapidly transited through the GI tract and accumulated in the colon and cecum of CamSA-treated mice. From there, C. difficile spores were slowly shed over a 96-hour period. To our knowledge, this is the first report of using molecular probes to obtain disease progression information for C. difficile infection.

  16. Break-induced ATR and Ddb1-Cul4(Cdt)² ubiquitin ligase-dependent nucleotide synthesis promotes homologous recombination repair in fission yeast

    DEFF Research Database (Denmark)

    Moss, Jennifer; Tinline-Purvis, Helen; Walker, Carol A

    2010-01-01

    Nucleotide synthesis is a universal response to DNA damage, but how this response facilitates DNA repair and cell survival is unclear. Here we establish a role for DNA damage-induced nucleotide synthesis in homologous recombination (HR) repair in fission yeast. Using a genetic screen, we found...... the Ddb1-Cul4(Cdt)² ubiquitin ligase complex and ribonucleotide reductase (RNR) to be required for HR repair of a DNA double-strand break (DSB). The Ddb1-Cul4(Cdt)² ubiquitin ligase complex is required for degradation of Spd1, an inhibitor of RNR in fission yeast. Accordingly, deleting spd1(+) suppressed...

  17. Clostridium difficile 027/BI/NAP1 encodes a hypertoxic and antigenically variable form of TcdB.

    Directory of Open Access Journals (Sweden)

    Jordi M Lanis

    Full Text Available The Clostridium difficile exotoxin, TcdB, which is a major virulence factor, varies between strains of this pathogen. Herein, we show that TcdB from the epidemic BI/NAP1/027 strain of C. difficile is more lethal, causes more extensive brain hemorrhage, and is antigenically variable from TcdB produced by previously studied strains of this pathogen (TcdB003. In mouse intoxication assays, TcdB from a ribotype 027 strain (TcdB027 was at least four fold more lethal than TcdB003. TcdB027 caused a previously undescribed brain hemorrhage in mice and this correlated with a heightened sensitivity of brain microvascular endothelial cells to the toxin. TcdB003 and TcdB027 also differed in their antigenic profiles and did not share cross-neutralizing epitopes in a major immunogenic region of the protein. Solid phase humoral mapping of epitopes in the carboxy-terminal domains (CTD of TcdB027 and TcdB003 identified 11 reactive epitopes that varied between the two forms of TcdB, and 13 epitopes that were shared or overlapping. Despite the epitope differences and absence of neutralizing epitopes in the CTD of TcdB027, a toxoid form of this toxin primed a strong protective response. These findings indicate TcdB027 is a more potent toxin than TcdB003 as measured by lethality assays and pathology, moreover the sequence differences between the two forms of TcdB alter antigenic epitopes and reduce cross-neutralization by antibodies targeting the CTD.

  18. CodY-Dependent Regulation of Sporulation in Clostridium difficile.

    Science.gov (United States)

    Nawrocki, Kathryn L; Edwards, Adrianne N; Daou, Nadine; Bouillaut, Laurent; McBride, Shonna M

    2016-08-01

    Clostridium difficile must form a spore to survive outside the gastrointestinal tract. The factors that trigger sporulation in C. difficile remain poorly understood. Previous studies have suggested that a link exists between nutritional status and sporulation initiation in C. difficile In this study, we investigated the impact of the global nutritional regulator CodY on sporulation in C. difficile strains from the historical 012 ribotype and the current epidemic 027 ribotype. Sporulation frequencies were increased in both backgrounds, demonstrating that CodY represses sporulation in C. difficile The 027 codY mutant exhibited a greater increase in spore formation than the 012 codY mutant. To determine the role of CodY in the observed sporulation phenotypes, we examined several factors that are known to influence sporulation in C. difficile Using transcriptional reporter fusions and quantitative reverse transcription-PCR (qRT-PCR) analysis, we found that two loci associated with the initiation of sporulation, opp and sinR, are regulated by CodY. The data demonstrate that CodY is a repressor of sporulation in C. difficile and that the impact of CodY on sporulation and expression of specific genes is significantly influenced by the strain background. These results suggest that the variability of CodY-dependent regulation is an important contributor to virulence and sporulation in current epidemic isolates. This report provides further evidence that nutritional state, virulence, and sporulation are linked in C. difficile This study sought to examine the relationship between nutrition and sporulation in C. difficile by examining the global nutritional regulator CodY. CodY is a known virulence and nutritional regulator of C. difficile, but its role in sporulation was unknown. Here, we demonstrate that CodY is a negative regulator of sporulation in two different ribotypes of C. difficile We also demonstrate that CodY regulates known effectors of sporulation, Opp and Sin

  19. Pseudomembranous Colitis: Not Always Caused by Clostridium difficile

    Directory of Open Access Journals (Sweden)

    Derek M. Tang

    2014-01-01

    Full Text Available Although classically pseudomembranous colitis is caused by Clostridium difficile, it can result from several etiologies. Certain medications, chemical injury, collagenous colitis, inflammatory bowel disease, ischemia, and other infectious pathogens can reportedly cause mucosal injury and subsequent pseudomembrane formation. We present the case of a middle-aged woman with vascular disease who was incorrectly diagnosed with refractory C. difficile infection due to the presence of pseudomembranes. Further imaging, endoscopy, and careful histopathology review revealed chronic ischemia as the cause of her pseudomembranous colitis and diarrhea. This case highlights the need for gastroenterologists to consider non-C. difficile etiologies when diagnosing pseudomembranous colitis.

  20. Clostridium difficile-ribotype 027 er en udfordring

    DEFF Research Database (Denmark)

    Nyboe Sommer, Trine; Ravn, Pernille; Gjørup, Ida

    2014-01-01

    Infection with Clostridium difficile is the primary infective cause of antibiotic-associated diarrhoea. In 2008, a major outbreak of CD027 took place in North Zealand, Denmark. We described this infection in a single medical department. Patients positive for C. difficile enlisted at Medical...... Department O, Herlev Hospital, in 2009 were included and demographic data were recorded. In total, 69 patients were included, average age 83 years, Charlson Comorbidity Score 4. Of all patients 24 died. Further studies are needed in order to treat and minimize infection with C. difficile....

  1. Topical botulinum toxin.

    Science.gov (United States)

    Collins, Ashley; Nasir, Adnan

    2010-03-01

    Nanotechnology is a rapidly growing discipline that capitalizes on the unique properties of matter engineered on the nanoscale. Vehicles incorporating nanotechnology have led to great strides in drug delivery, allowing for increased active ingredient stability, bioavailability, and site-specific targeting. Botulinum toxin has historically been used for the correction of neurological and neuromuscular disorders, such as torticollis, blepharospasm, and strabismus. Recent dermatological indications have been for the management of axillary hyperhydrosis and facial rhytides. Traditional methods of botulinum toxin delivery have been needle-based. These have been associated with increased pain and cost. Newer methods of botulinum toxin formulation have yielded topical preparations that are bioactive in small pilot clinical studies. While there are some risks associated with topical delivery, the refinement and standardization of delivery systems and techniques for the topical administration of botulinum toxin using nanotechnology is anticipated in the near future.

  2. [Epidemiology of Clostridium difficile infection in Spain].

    Science.gov (United States)

    Asensio, Angel; Monge, Diana

    2012-06-01

    There has been increasing interest in Clostridium difficile infection (CDI) due its association with healthcare and its impact on morbidity and mortality in the elderly. During the last few years there has been a growing increase in the number of published studies on the incidence, changes on the clinical presentation and on the epidemiology, with the description of new risk factors. The frequency of CDI in Spain is not sufficiently characterised. The available data indicates that incidence is within the range of that of surrounding countries but increasing. Furthermore, the high and growing use of broad spectrum antibiotics, both in our hospitals and in the community setting, are factors that favour the increase of the disease. The hyper-virulent ribotype 027 has not spread in our hospitals. We need to know with enhanced validity and accuracy the incidence of CDI, both community and healthcare-associated, the information on outbreaks, the incidence on certain population groups, the characterisation of circulating ribotypes and the impact of the disease in terms of mortality and health costs. We need to implement programs for the improvement of antibiotic therapy in the hospital, as well as in the community. Furthermore, the knowledge and the performance of standard precautions need to be improved, particularly hand hygiene, and the specific measures to limit the transmission of C. difficile among the healthcare institutions. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  3. Detection of Clostridium difficile in Retail Ground Meat Products in Manitoba

    Directory of Open Access Journals (Sweden)

    Monique Visser

    2012-01-01

    Full Text Available The aim of the present study was to determine whether Clostridium difficile was present in uncooked retail ground beef and ground pork products sold in Winnipeg, Manitoba. Using an alcohol treatment protocol and inoculation of cultures on C difficile Moxalactam Norfloxacin (CDMN, toxigenic C difficile was found in 6.3% of 48 meat samples. The C difficile isolates belonged to different pulsotypes, all of which had been previously isolated from the stool of Manitoba patients with C difficile disease. Because cooking of meat will not eradicate C difficile spores, this raises a concern regarding potential foodborne transmissibility of this organism.

  4. Clostridium difficile in Food and Animals: A Comprehensive Review.

    Science.gov (United States)

    Rodriguez, C; Taminiau, B; Van Broeck, J; Delmée, M; Daube, G

    2016-01-01

    Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present.

  5. Clostridium difficile infection in the community: a zoonotic disease?

    NARCIS (Netherlands)

    Hensgens, M.P.; Keessen, E.C.; Squire, M.M.; Riley, T.V.; Koene, M.G.J.; de Boer, E.; Lipman, L.J.A.; Kuijper, E.J.

    2012-01-01

    Clostridium difficile infections (CDIs) are traditionally seen in elderly and hospitalized patients who have used antibiotic therapy. In the community, CDIs requiring a visit to a general practitioner are increasingly occurring among young and relatively healthy individuals without known

  6. Clostridium difficile infections in the community: a zoonotic disease?

    NARCIS (Netherlands)

    Hensgens, M.P.M.; Keessen, A.M.; Squire, M.M.; Riley, T.V.; Koene, M.G.J.; Boer, de E.; Lipman, L.J.; Kuijper, E.J.

    2012-01-01

    Clostridium difficile infections (CDIs) are traditionally seen in elderly and hospitalized patients who have used antibiotic therapy. In the community, CDIs requiring a visit to a general practitioner are increasingly occurring among young and relatively healthy individuals without known

  7. Pomegranate extract exhibits in vitro activity against Clostridium difficile.

    Science.gov (United States)

    Finegold, Sydney M; Summanen, Paula H; Corbett, Karen; Downes, Julia; Henning, Susanne M; Li, Zhaoping

    2014-10-01

    To determine the possible utility of pomegranate extract in the management or prevention of Clostridium difficile infections or colonization. The activity of pomegranate was tested against 29 clinical C. difficile isolates using the Clinical and Laboratory Standards Institute-approved agar dilution technique. Total phenolics content of the pomegranate extract was determined by Folin-Ciocalteau colorimetric method and final concentrations of 6.25 to 400 μg/mL gallic acid equivalent were achieved in the agar. All strains had MICs at 12.5 to 25 mg/mL gallic acid equivalent range. Our results suggest antimicrobial in vitro activity for pomegranate extract against toxigenic C. difficile. Pomegranate extract may be a useful contributor to the management and prevention of C. difficile disease or colonization. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Clostridium difficile colonization and infection in patients with hepatic cirrhosis.

    Science.gov (United States)

    Yan, Dong; Chen, Yunbo; Lv, Tao; Huang, Yandi; Yang, Jiezuan; Li, Yongtao; Huang, Jianrong; Li, Lanjuan

    2017-10-01

    The aim of this study was to investigate the toxigenic Clostridium difficile colonization (CDC, colonization with toxigenic C. difficile but without symptoms) and C. difficile infection (CDI, active C. difficile infection resulting in disease symptoms) in hepatic cirrhosis patients, identify the risk factors of CDC, and determine the correlation between CDC and CDI. The strains of toxigenic C. difficile were isolated from patients with hepatic cirrhosis within 48 h after admission, followed by multilocus sequence typing (MLST). Patients were divided into toxigenic CDC group and noncolonized (NC) group according to the colonization. Logistic regression analysis was performed to analyse the risk factors for the CDC. Besides, the CDI incidence was compared between the two groups. Colonization of toxigenic C. difficile was identified in 104 cases (19.8 %). Eighteen sequence types (STs) were identified, among which ST-3, ST-54, ST-35 and ST-37 were the predominant types. Child-Pugh class C(relative risk, RR, 3.025; 95 % CI: 1.410-6.488), decrease of prothrombin time activity (PTA) (RR 2.180; 95 % CI: 1.368-3.476), decrease of platelet (RR 2.746; 95 % CI: 0.931-8.103) and concurrent hepatic encephalopathy (RR 1.740; 95 % CI: 1.012-2.990) were identified as the risk factors for the hepatic cirrhosis patients with CDC. The CDI incidence in the CDC group was also significantly higher than that of the NC group (26.0 % vs 1.7 %, Pdifficile colonization. Child's class C, decrease of PTA and platelet, and concurrent hepatic encephalopathy were the risk factors for the hepatic cirrhosis patients with C. difficile colonization. Hepatic cirrhosis patients with C. difficile colonization were more susceptible to CDI.

  9. Reactive arthritis induced by recurrent Clostridium difficile colitis

    Directory of Open Access Journals (Sweden)

    Allison Marr

    2012-01-01

    Full Text Available Clostridium difficile colitis is a common infection that can be difficult to resolve and may result in recurrent infections. Reactive arthritis is a rare presentation of this disease and its treatment is not well differentiated in the literature. We describe a case of reactive arthritis occurring in a patient with a history of recurrent Clostridium difficile colitis while currently receiving a taper of oral vancomycin. His arthritis symptoms resolved with corticosteroids and continued treatment with anticlostridial antibiotics.

  10. Suppressor Analysis of CRL4Cdt2 Defective and cdc48-353 Temperature Sensitive Mutants in Fission Yeast

    DEFF Research Database (Denmark)

    Marinova, Irina Nikolaeva

    chaperone-like complex involved in numerous cellular processes, including protein degradation, cell cycle control, DNA repair, and vesicle fusion. The cdc48 gene is essential in fission yeast and mutations or changes in Cdc48/p97 protein expression have been linked to neurological disorders and cancer......SummaryPart 1CRL4Cdt2 E3 ligase is a key regulator of cellular proliferation and genome integrity, as it promotes the degradation of proteins involved in cell cycle progression, DNA replication and repair. In fission yeast the small intrinsically disordered protein Spd1 is targeted for degradation...... that these mutations alleviate the checkpoint dependency, the DNA damage sensitivity and the meiotic defects associated with Spd1 accumulation. Further analysis showed that whereas the V40G and S43L substitutions do not have a significant impact on Suc22R2 nuclear import function of Spd1, they affect the interaction...

  11. [Nosocomial Clostridium difficile diarrhea--adverse effect of antibiotic therapy].

    Science.gov (United States)

    Lemeni, Daniela

    2010-01-01

    C. difficile is recognised as the main cause for colitis in hospitalised patients which are treated with antibiotics, chemotherapics or other drugs that disturb intestinal microbiota. Thus, a rapid and correct diagnostic of Clostridium difficile infections is essential for preventing nosocomial infection spread. Empiric therapy, regardless of the laboratory investigation results, is inadequate, especially in epidemic situations, as not all the cases of diarrhoea are due to C. difficile infection. Other risk factors for CDAD (Clostridiumn difficile Associated Diseases might be: prolonged hospitalization or residency in an asylum, age, existence of a severe chronic disease in the background nasogastric intubation, anti-ulcer drugs, at less extent gastrointestinal surgery, other immunosuppresive compounds etc. In our country, C. difficile infection is rather frequent in adults, though it is not always reported by clinicians. The circulation of endemic rybotype 027 in Romania is not well documented, the rybotype being extremely virulent and spread in other European countries. Hence the importance of extending the diagnostic capacity of C. difficile infection in order to allow detection of this rybotype among the strains isolated in our country.

  12. Control of Clostridium difficile infection by defined microbial communities

    Science.gov (United States)

    Collins, James

    2017-01-01

    Summary Each year in the United States, billions of dollars are spent combating almost half a million Clostridium difficile infections (CDI) and trying to reduce the ~29,000 patient deaths where C. difficile has an attributed role (1). In Europe, disease prevalence varies by country and level of surveillance, though yearly costs are estimated at €3 billion (2). One factor contributing to the significant healthcare burden of C. difficile is the relatively high frequency of recurrent C. difficile infections(3). Recurrent C. difficile infection (rCDI), i.e., a second episode of symptomatic CDI occurring within eight weeks of successful initial CDI treatment, occurs in ~25% of patients with 35-65% of these patients experiencing multiple episodes of recurrent disease(4, 5). Using microbial communities to treat rCDI, either as whole fecal transplants or as defined consortia of bacterial isolates have shown great success (in the case of fecal transplants) or potential promise (in the case of defined consortia of isolates). This review will briefly summarize the epidemiology and physiology of C. difficile infection, describe our current understanding of how fecal microbiota transplants treat recurrent CDI, and outline potential ways through which that knowledge can be used to rationally-design and test alternative microbe-based therapeutics. PMID:28936948

  13. Incidence and surveillance of infections from Clostridium difficile: the experience at the Galliera of Genoa in the three-year period 2004-2006

    Directory of Open Access Journals (Sweden)

    David Usiglio

    2009-03-01

    Full Text Available Introduction Clostridium difficile is a Gram-positive bacillus, anaerobic, sporogenous ,with oro-faecal transmission.The formation of the spores can persist in a long time, encouraging the transmission. Use of broad-spectrum antibiotics, age, alteration of intestinal flora are the most common risk factors that expose the subject to any subsequent colonization and infection. The hospital staff is the main vehicle of transmission and the probability of contracting an infection is proportional to the duration of hospitalization in patients infected with cohabitation. Objectives The infections surveillance of C. difficile is a instrument to monitor procedures for the control of hospital infections, and may be useful to highlight and point out shortcomings in the system. Materials and Methods The data are the results of tests for the detection of toxins on stools during the period 2004-2006, distributed quarterly to study the seasonal, divided by individual UO the hospital and later for area hospital. Results and conclusions The incidence of infection from C. difficile in the last three years has been in constant increase (from 7 to 12.5 case/1000 admissions. Much of increase is attributable to community infections 3 case/1000 admissions (2004 up to about 6 case/1000 admissions (2006. Substantially increasing content of hospital infections (5-6 case/1000 admissions.

  14. Perceptions of Clostridium difficile infections among infection control professionals in Taiwan.

    Science.gov (United States)

    Hung, Yuan-Pin; Lee, Jen-Chieh; Lin, Hsiao-Ju; Chiu, Chun-Wei; Wu, Jia-Ling; Liu, Hsiao-Chieh; Huang, I-Hsiu; Tsai, Pei-Jane; Ko, Wen-Chien

    2017-08-01

    High Clostridium difficile colonization and infection rates among hospitalized patients had been noted in Taiwan. Nevertheless, the cognition about clinical diagnosis and management of CDI among infection control professionals in Taiwan is not clear. A 24-item survey questionnaire about the diagnosis, therapy, or infection control policies toward CDI was distributed in the annual meeting of the Infectious Disease Society of Taiwan (IDST) in October 2015 and Infectious Control Society of Taiwan (ICST) in April 2016. Totally 441 individuals responded to the survey, and 280 (63.5%) participants would routinely monitor the prevalence of CDI and 347 (78.7%) reported the formulation of infection control policies of CDI in their hospital, including contact precaution (75.7%), wearing gloves (88.9%) or dressing (80.0%) at patient care, single room isolation (49.7%), preference of soap or disinfectant-based sanitizer (83.2%) and avoidance of alcohol-based sanitizer (63.3%), and environmental disinfection with 1000 ppm bleach (87.1%). For the timing of contact precaution discontinuation isolation for CDI patients, most (39.9%) participants suggested the time point of the absence of C. difficile toxin in feces. To treat mild CDI, most (61.9%) participants preferred oral metronidazole, and for severe CDI 26.1% would prescribe oral vancomycin as the drug of choice. There were substantial gaps in infection control polices and therapeutic choices for CDI between international guidelines and the perceptions of medical professionals in Taiwan. Professional education program and the setup of guideline for CDI should be considered in Taiwan. Copyright © 2017. Published by Elsevier B.V.

  15. Struggling with recurrent Clostridium difficile infections: is donor faeces the solution?

    NARCIS (Netherlands)

    van Nood, E.; Speelman, P.; Kuijper, E. J.; Keller, J. J.

    2009-01-01

    Patients with recurrent Clostridium difficile infections (CDI) in hospitals and the community constitute an increasing treatment problem. While most patients with a first infection respond to either metronidazole or oral vancomycin, therapy in recurrent C. difficile infections tends to fail

  16. Marine and freshwater toxins.

    Science.gov (United States)

    Hungerford, James M

    2006-01-01

    In a very busy and exciting year, 2005 included First Action approval of a much needed official method for paralytic shellfish toxins and multiple international toxin symposia highlighted by groundbreaking research. These are the first-year milestones and activities of the Marine and Freshwater Toxins Task Force and Analytical Community. Inaugurated in 2004 and described in detail in last year's General Referee Report (1) this international toxins group has grown to 150 members from many regions and countries. Perhaps most important they are now making important and global contributions to food safety and to providing alternatives to animal-based assays. Official Method 2005.06 was first approved in late 2004 by the Task Force and subsequently Official First Action in 2005 (2) by the Methods Committee on Natural Toxins and Food Allergens and the Official Methods Board. This nonproprietary method (3) is a precolumn oxidation, liquid chromatographic method that makes good use of fluorescence detection to provide high sensitivity detection of the saxitoxins. It has also proven to be rugged enough for regulatory use and the highest level of validation. As pointed out in the report of method principle investigator and Study Director James Lawrence, approval of 2005.06 now provides the first official alternative to the mouse bioassay after many decades of shellfish monitoring. This past year in April 2005 the group also held their first international conference, "Marine and Freshwater Toxins Analysis: Ist Joint Symposium and AOAC Task Force Meeting," in Baiona, Spain. The 4-day conference consisted of research and stakeholder presentations and symposium-integrated subgroup sessions on ciguatoxins, saxitoxin assays and liquid chromatography (LC) methods for saxitoxins and domoic acids, okadaiates and azaspiracids, and yessotoxins. Many of these subgroups were recently formed in 2005 and are working towards their goals of producing officially validated analytical methods

  17. The Epidemiology and Economic Burden of Clostridium difficile Infection in Korea

    OpenAIRE

    Choi, Hyung-Yun; Park, So-Youn; Kim, Young-Ae; Yoon, Tai-Young; Choi, Joong-Myung; Choe, Bong-Keun; Ahn, So-Hee; Yoon, Seok-Jun; Lee, Ye-Rin; Oh, In-Hwan

    2015-01-01

    The prevalence of Clostridium difficile infection and the associated burden have recently increased in many countries. While the main risk factors for C. difficile infection include old age and antibiotic use, the prevalence of this infection is increasing in low-risk groups. These trends highlight the need for research on C. difficile infection. This study pointed out the prevalence and economic burden of C. difficile infection and uses the representative national data which is primarily fro...

  18. Factores de riesgo para la infección por Clostridium difficile Risk factors for Clostridium difficileinfection

    Directory of Open Access Journals (Sweden)

    María Gabriela Becerra

    2011-12-01

    Full Text Available Introducción. Clostridium difficile es un bacilo Gram positivo, anaerobio estricto y formador de esporas, capaz de persistir bajo condiciones adversas durante mucho tiempo. Es una de las causas más frecuentes de infección asociada a la atención en salud, cuyas manifestaciones clínicas van desde diarrea sin complicaciones hasta sepsis e, incluso, la muerte. El propósito de este estudio fue determinar los factores de riesgo para infección por C. difficile en un hospital universitario. Materiales y métodos. Se llevó a cabo un estudio de casos y controles de pacientes mayores de 18 años, de ambos sexos, que presentaron diarrea durante su hospitalización en el Hospital Universitario de San Vicente Fundación y a quienes se les realizó la prueba para la detección de las toxina A y B de C. difficile, entre septiembre de 2009 y diciembre de 2010. A partir de esta población se seleccionaron 22 casos y 44 controles. Resultados. Los factores de riesgo que se encontraron asociados fueron: edad mayor de 65 años (OR=3,4; IC95% 1,1-10,1; p=0,05, la estancia en unidad de cuidados intensivos (OR=4,0; IC95% 1,3-12,2; p=0,02 y el uso de inhibidores de la bomba de protones (OR=5,15; IC95% 1,6-15,9; pIntroduction: Clostridium difficile is a Gram positive strict anaerobic spore-forming bacillus, so it is able to persist under adverse conditions for long time. This microorganism is a the most common cause of health care associated infection, with clinical manifestations ranging from uncomplicated diarrhea to sepsis and even death. The purpose of this study was to determine the risk factors for C. difficile infection in a teaching hospital. Materials and methods: We conducted a case control study in patients over 18 years, of both gender, who had developed diarrhea during their hospitalization in teaching Hospital of San Vicente Fundación and who underwent the toxin test for C. difficile, between September 2009 and December 2010. From this population we

  19. Toxins of filamentous fungi.

    Science.gov (United States)

    Bhatnagar, Deepak; Yu, Jiujiang; Ehrlich, Kenneth C

    2002-01-01

    Mycotoxins are low-molecular-weight secondary metabolites of fungi. The most significant mycotoxins are contaminants of agricultural commodities, foods and feeds. Fungi that produce these toxins do so both prior to harvest and during storage. Although contamination of commodities by toxigenic fungi occurs frequently in areas with a hot and humid climate (i.e. conditions favorable for fungal growth), they can also be found in temperate conditions. Production of mycotoxins is dependent upon the type of producing fungus and environmental conditions such as the substrate, water activity (moisture and relative humidity), duration of exposure to stress conditions and microbial, insect or other animal interactions. Although outbreaks of mycotoxicoses in humans have been documented, several of these have not been well characterized, neither has a direct correlation between the mycotoxin and resulting toxic effect been well established in vivo. Even though the specific modes of action of most of the toxins are not well established, acute and chronic effects in prokaryotic and eukaryotic systems, including humans have been reported. The toxicity of the mycotoxins varies considerably with the toxin, the animal species exposed to it, and the extent of exposure, age and nutritional status. Most of the toxic effects of mycotoxins are limited to specific organs, but several mycotoxins affect many organs. Induction of cancer by some mycotoxins is a major concern as a chronic effect of these toxins. It is nearly impossible to eliminate mycotoxins from the foods and feed in spite of the regulatory efforts at the national and international levels to remove the contaminated commodities. This is because mycotoxins are highly stable compounds, the producing fungi are ubiquitous, and food contamination can occur both before and after harvest. Nevertheless, good farm management practices and adequate storage facilities minimize the toxin contamination problems. Current research is

  20. The potential beneficial role of faecal microbiota transplantation in diseases other than Clostridium difficile infection

    NARCIS (Netherlands)

    Singh, R.; Nieuwdorp, M.; ten Berge, I. J. M.; Bemelman, F. J.; Geerlings, S. E.

    2014-01-01

    This review gives an outline of the indications for faecal microbiota transplantation (FMT) for diseases other than Clostridium difficile (C. difficile) infection. The remarkable efficacy of FMT against C. difficile infection has already been demonstrated. The use of FMT for other diseases, such as

  1. The Role of Glutamate Dehydrogenase (GDH Testing Assay in the Diagnosis of Clostridium difficile Infections: A High Sensitive Screening Test and an Essential Step in the Proposed Laboratory Diagnosis Workflow for Developing Countries like China.

    Directory of Open Access Journals (Sweden)

    Jing-Wei Cheng

    Full Text Available The incidence and severity of Clostridium difficile infection (CDI in North America and Europe has increased significantly since the 2000s. However, CDI is not widely recognized in China and other developing countries due to limited laboratory diagnostic capacity and low awareness. Most published studies on laboratory workflows for CDI diagnosis are from developed countries, and thus may not be suitable for most developing countries. Therefore, an alternative strategy for developing countries is needed. In this study, we evaluated the performance of the Glutamate Dehydrogenase (GDH test and its associated workflow on 416 fecal specimens from suspected CDI cases. The assay exhibited excellent sensitivity (100.0% and specificity (92.8%, compared to culture based method, and thus could be a good screening marker for C. difficile but not for indication of toxin production. The VIDAS CDAB assay, which can detect toxin A/B directly from fecal specimens, showed good specificity (99.7% and positive predictive value (97.2%, but low sensitivity (45.0% and negative predictive value (88.3%, compared with PCR-based toxin gene detection. Therefore, we propose a practical and efficient GDH test based workflow strategy for the laboratory diagnosis of CDI in developing countries like China. By applying this new workflow, the CDI laboratory diagnosis rate was notably improved in our center, yet the increasing cost was kept at a minimum level. Furthermore, to gain some insights into the genetic population structure of C. difficile isolates from our hospital, we performed MLST and PCR toxin gene typing.

  2. Headache and botulinum toxin

    OpenAIRE

    Porta, M.; Camerlingo, M.

    2005-01-01

    The authors discuss clinical and international experience about botulinum toxins (BTX types A and B) in headache treatment. Data from literature suggest good results for the treatment of tensiontype headache, migraine and chronic tension–type headache. In the present paper mechanisms of action and injection sites will also be discussed.

  3. Botulinum Toxin for Rhinitis.

    Science.gov (United States)

    Ozcan, Cengiz; Ismi, Onur

    2016-08-01

    Rhinitis is a common clinical entity. Besides nasal obstruction, itching, and sneezing, one of the most important symptoms of rhinitis is nasal hypersecretion produced by nasal glands and exudate from the nasal vascular bed. Allergic rhinitis is an IgE-mediated inflammatory reaction of nasal mucosa after exposure to environmental allergens. Idiopathic rhinitis describes rhinitis symptoms that occur after non-allergic, noninfectious irritants. Specific allergen avoidance, topical nasal decongestants, nasal corticosteroids, immunotherapy, and sinonasal surgery are the main treatment options. Because the current treatment modalities are not enough for reducing rhinorrhea in some patients, novel treatment options are required to solve this problem. Botulinum toxin is an exotoxin generated by Clostridium botulinum. It disturbs the signal transmission at the neuromuscular and neuroglandular junction by inhibiting the acetylcholine release from the presynaptic nerve terminal. It has been widely used in neuromuscular, hypersecretory, and autonomic nerve system disorders. There have been a lot of published articles concerning the effect of this toxin on rhinitis symptoms. Based on the results of these reports, intranasal botulinum toxin A administration appears to be a safe and effective treatment method for decreasing rhinitis symptoms in rhinitis patients with a long-lasting effect. Botulinum toxin type A will be a good treatment option for the chronic rhinitis patients who are resistant to other treatment methods.

  4. Diffusion of Botulinum Toxins

    Directory of Open Access Journals (Sweden)

    Matthew A. Brodsky

    2012-08-01

    Full Text Available Background: It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion.Methods: This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method. It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB.Results: Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others.Discussion: Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

  5. Topical Botulinum Toxin

    OpenAIRE

    Collins, Ashley; Nasir, Adnan

    2010-01-01

    Nanotechnology is a rapidly growing discipline that capitalizes on the unique properties of matter engineered on the nanoscale. Vehicles incorporating nanotechnology have led to great strides in drug delivery, allowing for increased active ingredient stability, bioavailability, and site-specific targeting. Botulinum toxin has historically been used for the correction of neurological and neuromuscular disorders, such as torticollis, blepharospasm, and strabismus. Recent dermatological indicati...

  6. The potential for emerging therapeutic options for Clostridium difficile infection

    Science.gov (United States)

    Mathur, Harsh; Rea, Mary C; Cotter, Paul D; Ross, R Paul; Hill, Colin

    2014-01-01

    Clostridium difficile is mainly a nosocomial pathogen and is a significant cause of antibiotic-associated diarrhea. It is also implicated in the majority of cases of pseudomembranous colitis. Recently, advancements in next generation sequencing technology (NGS) have highlighted the extent of damage to the gut microbiota caused by broad-spectrum antibiotics, often resulting in C. difficile infection (CDI). Currently the treatment of choice for CDI involves the use of metronidazole and vancomycin. However, recurrence and relapse of CDI, even after rounds of metronidazole/vancomycin administration is a problem that must be addressed. The efficacy of alternative antibiotics such as fidaxomicin, rifaximin, nitazoxanide, ramoplanin and tigecycline, as well as faecal microbiota transplantation has been assessed and some have yielded positive outcomes against C. difficile. Some bacteriocins have also shown promising effects against C. difficile in recent years. In light of this, the potential for emerging treatment options and efficacy of anti-C. difficile vaccines are discussed in this review. PMID:25564777

  7. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  8. The Potential Value of Clostridium difficile Vaccine: An Economic Computer Simulation Model

    Science.gov (United States)

    Lee, Bruce Y.; Popovich, Michael J.; Tian, Ye; Bailey, Rachel R.; Ufberg, Paul J.; Wiringa, Ann E.; Muder, Robert R.

    2010-01-01

    Efforts are currently underway to develop a vaccine against Clostridium difficile infection (CDI). We developed two decision analytic Monte Carlo computer simulation models: (1) an Initial Prevention Model depicting the decision whether to administer C. difficile vaccine to patients at-risk for CDI and (2) a Recurrence Prevention Model depicting the decision whether to administer C. difficile vaccine to prevent CDI recurrence. Our results suggest that a C. difficile vaccine could be cost-effective over a wide range of C. difficile risk, vaccine costs, and vaccine efficacies especially when being used post-CDI treatment to prevent recurrent disease. PMID:20541582

  9. Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): Characterization, Manufacture, Mechanisms of Action, and Quality Control of a Specific Probiotic Combination for Primary Prevention of Clostridium difficile Infection.

    Science.gov (United States)

    Auclair, Julie; Frappier, Martin; Millette, Mathieu

    2015-05-15

    A specific probiotic formulation composed of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+) has been marketed in North America since 1996. The strains and the commercial products have been evaluated for safety, identity, gastrointestinal survival, and stability throughout shelf life. The capacity of both the fermented beverages and the capsules to reduce incidences of antibiotic-associated diarrhea and Clostridium difficile infection (CDI) has been demonstrated in human clinical trials. Individual strains and the finished products have shown antimicrobial activity against C. difficile and toxin A/B neutralization capacity in vitro. The use of this specific probiotic formulation as part of a bundle of preventive measures to control CDI in healthcare settings is discussed. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Rectal bacteriotherapy for recurrent Clostridium difficile-associated diarrhoea

    DEFF Research Database (Denmark)

    Tvede, M; Tinggaard, M; Helms, M

    2015-01-01

    Clostridium difficile infection is one of the most common nosocomial infections. Among other alternatives to standard treatment with vancomycin for recurrent infection are faecal microbiota transplantation and rectal bacteriotherapy with a fixed mixture of intestinal bacterial strains isolated from...... for relapsing C. difficile in Denmark, 2000-2012. The primary end point was recurrent diarrhoea within 30 days after treatment. A total of 55 patients were included in this case series. Thirty-five patients (64%) had no recurrence within 30 days of bacteriotherapy. Patients with recurrence tended to be older....... difficile episode less than 6 months before bacteriotherapy. The most common adverse events were abdominal pain (10.9%) and worsening diarrhoea (4.3%). One patient was hospitalized 10 days after treatment with appendicitis, fever, and Escherichia coli bacteremia. The results from this study indicate...

  11. Physical and biological data collected with CDT, fluorometer, and SeaSoar aboard the ship WECOMA as part of Global Ocean Ecosystem Dynamics (GLOBEC) in the North Pacific Ocean from May 30 to June 16 2000 (NODC Accession 0000986)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and biological data collected with CDT, fluorometer, and SeaSoar aboard the ship WECOMA in the North Pacific Ocean from May 30 to June 16 2000. These data...

  12. Pseudo-outbreak of Clostridium difficile associated diarrhea (CDAD in a tertiary-care hospital Pseudo-surto de diarréia associada a Clostridium difficile (DACD em hospital terciário

    Directory of Open Access Journals (Sweden)

    M. Beatriz Souza Dias

    2010-06-01

    Full Text Available The objective of this study was to describe a pseudo-outbreak of C. difficile in a hospital, following a change in the method used to detect the toxin. In February 2002, there were two cases of CDAD and in March 7 occurred, coinciding with a change of the test (from detection of toxin A to toxin A/B. An outbreak was suspected. Active surveillance and education of staff were started. A CDAD case was defined as a patient with acute onset of diarrhea (³ three episodes of liquid stools and a positive stool test. They were classified as hospital or community-acquired. Stool samples were also collected for C. difficile culture and isolates were typed using AP-PCR. From March 2002 through December 2003 there were 138 cases of CDAD: 70% were hospital-acquired and among the 30% with CDAD present on admission, most (81% came directly from the community (50% had no history of hospitalization. Fifty-two percent of hospital-acquired CDAD and 94% of cases on admission had already used antibiotics. The incidence of CDAD in hospitalized patients during surveillance was 3.3 per 1000 patient-admissions. The incidence of CDAD present on admission was 6.1/1000 patients. Sixteen isolates were typed and presented 13 different profiles. In conclusion, the CDAD increase in our study occurred due to change in diagnostic methods and not due to an outbreak, as suspected initially. The incidence in hospitalized patients was much lower than in reported outbreaks. There were 13 molecular types suggesting that an outbreak did not occur. CDAD was largely community-acquired.O objetivo deste estudo foi descrever um pseudo-surto de C. difficile em um hospital após a troca do método de detecção de toxina. Em fevereiro de 2002 houve dois casos de DACD e em março ocorreram sete casos, que coincidiram com a mudança de teste (que detectava apenas toxina A e passou a detectar toxinas A e B. Foi suspeitado que houvesse um surto e vigilância ativa e reforço educacional para os

  13. Global analysis of the sporulation pathway of Clostridium difficile.

    Science.gov (United States)

    Fimlaid, Kelly A; Bond, Jeffrey P; Schutz, Kristin C; Putnam, Emily E; Leung, Jacqueline M; Lawley, Trevor D; Shen, Aimee

    2013-01-01

    The Gram-positive, spore-forming pathogen Clostridium difficile is the leading definable cause of healthcare-associated diarrhea worldwide. C. difficile infections are difficult to treat because of their frequent recurrence, which can cause life-threatening complications such as pseudomembranous colitis. The spores of C. difficile are responsible for these high rates of recurrence, since they are the major transmissive form of the organism and resistant to antibiotics and many disinfectants. Despite the importance of spores to the pathogenesis of C. difficile, little is known about their composition or formation. Based on studies in Bacillus subtilis and other Clostridium spp., the sigma factors σ(F), σ(E), σ(G), and σ(K) are predicted to control the transcription of genes required for sporulation, although their specific functions vary depending on the organism. In order to determine the roles of σ(F), σ(E), σ(G), and σ(K) in regulating C. difficile sporulation, we generated loss-of-function mutations in genes encoding these sporulation sigma factors and performed RNA-Sequencing to identify specific sigma factor-dependent genes. This analysis identified 224 genes whose expression was collectively activated by sporulation sigma factors: 183 were σ(F)-dependent, 169 were σ(E)-dependent, 34 were σ(G)-dependent, and 31 were σ(K)-dependent. In contrast with B. subtilis, C. difficile σ(E) was dispensable for σ(G) activation, σ(G) was dispensable for σ(K) activation, and σ(F) was required for post-translationally activating σ(G). Collectively, these results provide the first genome-wide transcriptional analysis of genes induced by specific sporulation sigma factors in the Clostridia and highlight that diverse mechanisms regulate sporulation sigma factor activity in the Firmicutes.

  14. Antimicrobial susceptibility of Clostridium difficile isolated in Thailand

    Directory of Open Access Journals (Sweden)

    Papanin Putsathit

    2017-06-01

    Full Text Available Abstract Background Exposure to antimicrobials is the major risk factor associated with Clostridium difficile infection (CDI. Paradoxically, treatment of CDI with antimicrobials remains the preferred option. To date, only three studies have investigated the antimicrobial susceptibility of C. difficile from Thailand, two of which were published in the 1990s. This study aimed to investigate the contemporary antibiotic susceptibility of C. difficile isolated from patients in Thailand. Methods A collection of 105 C. difficile isolated from inpatients admitted at Siriraj Hospital in Bangkok in 2015 was tested for their susceptibility to nine antimicrobials via an agar incorporation method. Results All isolates were susceptible to vancomycin, metronidazole, amoxicillin/clavulanate and meropenem. Resistance to clindamycin, erythromycin and moxifloxacin was observed in 73.3%, 35.2% and 21.0% of the isolates, respectively. The in vitro activity of fidaxomicin (MIC50/MIC90 0.06/0.25 mg/L was superior to first-line therapies vancomycin (MIC50/MIC90 1/2 mg/L and metronidazole (MIC50/MIC90 0.25/0.25 mg/L. Rifaximin exhibited potent activity against 85.7% of the isolates (MIC ≤0.03 mg/L, and its MIC50 (0.015 mg/L was the lowest among all antimicrobials tested. The prevalence of multi-drug resistant C. difficile, defined by resistance to ≥3 antimicrobials, was 21.9% (23/105. Conclusions A high level of resistance against multiple classes of antimicrobial was observed, emphasising the need for enhanced antimicrobial stewardship and educational programmes to effectively disseminate information regarding C. difficile awareness and appropriate use of antimicrobials to healthcare workers and the general public.

  15. Optimization of CDT-1 and XYL1 Expression for Balanced Co-Production of Ethanol and Xylitol from Cellobiose and Xylose by Engineered Saccharomyces cerevisiae

    Science.gov (United States)

    Zha, Jian; Li, Bing-Zhi; Shen, Ming-Hua; Hu, Meng-Long; Song, Hao; Yuan, Ying-Jin

    2013-01-01

    Production of ethanol and xylitol from lignocellulosic hydrolysates is an alternative to the traditional production of ethanol in utilizing biomass. However, the conversion efficiency of xylose to xylitol is restricted by glucose repression, causing a low xylitol titer. To this end, we cloned genes CDT-1 (encoding a cellodextrin transporter) and gh1-1 (encoding an intracellular β-glucosidase) from Neurospora crassa and XYL1 (encoding a xylose reductase that converts xylose into xylitol) from Scheffersomyces stipitis into Saccharomyces cerevisiae, enabling simultaneous production of ethanol and xylitol from a mixture of cellobiose and xylose (main components of lignocellulosic hydrolysates). We further optimized the expression levels of CDT-1 and XYL1 by manipulating their promoters and copy-numbers, and constructed an engineered S. cerevisiae strain (carrying one copy of PGK1p-CDT1 and two copies of TDH3p-XYL1), which showed an 85.7% increase in xylitol production from the mixture of cellobiose and xylose than that from the mixture of glucose and xylose. Thus, we achieved a balanced co-fermentation of cellobiose (0.165 g/L/h) and xylose (0.162 g/L/h) at similar rates to co-produce ethanol (0.36 g/g) and xylitol (1.00 g/g). PMID:23844185

  16. Optimization of CDT-1 and XYL1 expression for balanced co-production of ethanol and xylitol from cellobiose and xylose by engineered Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Jian Zha

    Full Text Available Production of ethanol and xylitol from lignocellulosic hydrolysates is an alternative to the traditional production of ethanol in utilizing biomass. However, the conversion efficiency of xylose to xylitol is restricted by glucose repression, causing a low xylitol titer. To this end, we cloned genes CDT-1 (encoding a cellodextrin transporter and gh1-1 (encoding an intracellular β-glucosidase from Neurospora crassa and XYL1 (encoding a xylose reductase that converts xylose into xylitol from Scheffersomyces stipitis into Saccharomyces cerevisiae, enabling simultaneous production of ethanol and xylitol from a mixture of cellobiose and xylose (main components of lignocellulosic hydrolysates. We further optimized the expression levels of CDT-1 and XYL1 by manipulating their promoters and copy-numbers, and constructed an engineered S. cerevisiae strain (carrying one copy of PGK1p-CDT1 and two copies of TDH3p-XYL1, which showed an 85.7% increase in xylitol production from the mixture of cellobiose and xylose than that from the mixture of glucose and xylose. Thus, we achieved a balanced co-fermentation of cellobiose (0.165 g/L/h and xylose (0.162 g/L/h at similar rates to co-produce ethanol (0.36 g/g and xylitol (1.00 g/g.

  17. Open-ringed structure of the Cdt1-Mcm2-7 complex as a precursor of the MCM double hexamer.

    Science.gov (United States)

    Zhai, Yuanliang; Cheng, Erchao; Wu, Hao; Li, Ningning; Yung, Philip Yuk Kwong; Gao, Ning; Tye, Bik-Kwoon

    2017-03-01

    The minichromosome maintenance complex (MCM) hexameric complex (Mcm2-7) forms the core of the eukaryotic replicative helicase. During G1 phase, two Cdt1-Mcm2-7 heptamers are loaded onto each replication origin by the origin-recognition complex (ORC) and Cdc6 to form an inactive MCM double hexamer (DH), but the detailed loading mechanism remains unclear. Here we examine the structures of the yeast MCM hexamer and Cdt1-MCM heptamer from Saccharomyces cerevisiae. Both complexes form left-handed coil structures with a 10-15-Å gap between Mcm5 and Mcm2, and a central channel that is occluded by the C-terminal domain winged-helix motif of Mcm5. Cdt1 wraps around the N-terminal regions of Mcm2, Mcm6 and Mcm4 to stabilize the whole complex. The intrinsic coiled structures of the precursors provide insights into the DH formation, and suggest a spring-action model for the MCM during the initial origin melting and the subsequent DNA unwinding.

  18. Toxins and drug discovery.

    Science.gov (United States)

    Harvey, Alan L

    2014-12-15

    Components from venoms have stimulated many drug discovery projects, with some notable successes. These are briefly reviewed, from captopril to ziconotide. However, there have been many more disappointments on the road from toxin discovery to approval of a new medicine. Drug discovery and development is an inherently risky business, and the main causes of failure during development programmes are outlined in order to highlight steps that might be taken to increase the chances of success with toxin-based drug discovery. These include having a clear focus on unmet therapeutic needs, concentrating on targets that are well-validated in terms of their relevance to the disease in question, making use of phenotypic screening rather than molecular-based assays, and working with development partners with the resources required for the long and expensive development process. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

  19. The Rise and Fall of Metronidazole for Clostridium difficile Infection.

    Science.gov (United States)

    Chahine, Elias B

    2018-06-01

    Clostridium difficile is posing urgent health threats. Older studies have shown that metronidazole and vancomycin are equally effective in the treatment of Clostridium difficile infection (CDI). Given its inexpensive cost and low propensity to select antimicrobial resistant organisms, metronidazole became rapidly the drug of choice despite its pharmacokinetic limitations in the treatment of CDI. However, newer studies demonstrated that metronidazole is inferior to vancomycin, prompting clinicians to change their long-standing position on using metronidazole for mild to moderate infections and on reserving vancomycin for severe infections. Moving forward, metronidazole will fall out of favor in the treatment of CDI.

  20. First clinical and microbiological characterization of Clostridium difficile infection in a Croatian University Hospital.

    Science.gov (United States)

    Novak, Anita; Spigaglia, Patrizia; Barbanti, Fabrizio; Goic-Barisic, Ivana; Tonkic, Marija

    2014-12-01

    Clinical background and molecular epidemiology of Clostridium difficile infection (CDI) in the University Hospital Centre Split were investigated from January 2010 to December 2011. In total, 54 patients with first episode of CDI were consecutively included in the study based on the positive EIA test specific for A and B toxins. Demographic and clinical data were prospectively analyzed from medical records. CDI incidence rate was 0.6 per 10,000 patient-days. Thirty six cases (70.6%) were healthcare-associated, twelve cases (23.5%) were community-associated and three (5.9%) were indeterminate. Six patients (11.7%) had suffered one or more recurrences and 37 patients (72.5%) showed severe CDI. Prior therapy with third generation cephalosporin was significantly associated with severe CDI (Pdifficile strains were isolated and 50 of them were available for PCR-ribotyping. Sixteen different PCR-ribotypes were identified. The most prevalent were PCR-ribotype 001 (27.8%) and 014/020 (24.1%). Twenty three strains were resistant to at least one of the antibiotics tested. Among resistant strains, three (13.0%)--all PCR-ribotype 001--were multi-resistant. Resistance to fluoroquinolones was significantly higher in strains that caused infection after previous use of fluoroquinolones (P=0.04). Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Occurrence of Clostridium difficile in two types of wastewater treatment plants

    Directory of Open Access Journals (Sweden)

    Mahnaz Nikaeen

    2015-07-01

    Full Text Available Wastewater is a potential environmental source of Clostridium difficile, although a direct link with community-acquired C. difficile infection (CA-CDI in humans has not yet been established. The present study was performed to determine the occurrence of C. difficile in two types of wastewater treatment plants (WWTPs in Isfahan, Iran. A total of 95 samples were taken from a conventional activated sludge treatment plant and a waste stabilization ponds system, and analyzed for the presence of C. difficile. C. difficile was found in 13.6% (3/22 of digested sludge samples. However, no C. difficile was detected in inlet and outlet samples or in raw sludge of activated sludge. C. difficile was also detected in 5% (2/40 of the samples from waste stabilization ponds. Polymerase chain reaction (PCR analysis showed that all strains of C. difficile detected were toxigenic (tcdB gene positive. This study shows that C. difficile was present in WWTPs, which might constitute a potential source of community-acquired C. difficile infection.

  2. High Variability in Nosocomial Clostridium difficile Infection Rates Across Hospitals After Colorectal Resection.

    Science.gov (United States)

    Aquina, Christopher T; Probst, Christian P; Becerra, Adan Z; Hensley, Bradley J; Iannuzzi, James C; Noyes, Katia; Monson, John R T; Fleming, Fergal J

    2016-04-01

    Hospital-acquired Clostridium difficile infection is associated with adverse patient outcomes and high medical costs. The incidence and severity of C. difficile has been rising in both medical and surgical patients. Our aim was to assess risk factors and variation associated with the development of nosocomial C. difficile colitis among patients undergoing colorectal resection. This was a retrospective cohort study. The study included segmental colectomy and proctectomy cases in New York State from 2005 to 2013. The study cohort included 150,878 colorectal resections. Patients with a documented previous history of C. difficile infection or residence outside of New York State were excluded. A diagnosis of C. difficile colitis either during the index hospital stay or on readmission within 30 days was the main measure. C. difficile colitis occurred in 3323 patients (2.2%). Unadjusted C. difficile colitis rates ranged from 0% to 11.3% among surgeons and 0% to 6.8% among hospitals. After controlling for patient, surgeon, and hospital characteristics using mixed-effects multivariable analysis, significant unexplained variation in C. difficile rates remained present across hospitals but not surgeons. Patient factors explained only 24% of the total hospital-level variation, and known surgeon and hospital-level characteristics explained an additional 8% of the total hospital-level variation. Therefore, ≈70% of the hospital variation in C. difficile infection rates remained unexplained by captured patient, surgeon, and hospital factors. Furthermore, there was an ≈5-fold difference in adjusted C. difficile rates across hospitals. A limited set of hospital and surgeon characteristics was available. Colorectal surgery patients appear to be at high risk for C. difficile infection, and alarming variation in nosocomial C. difficile infection rates currently exists among hospitals after colorectal resection. Given the high morbidity and cost associated with C. difficile colitis

  3. Flooding and Clostridium difficile infection: a case-crossover analysis

    Science.gov (United States)

    Clostridium difficile is a bacterium that can spread by water. It often causes acute gastrointestinal illness in older adults who are hospttalized and/or receiving antibiotics; however, community­ associated infections affecting otherwise healthy individuals have become more comm...

  4. Cost-effectiveness in Clostridium difficile treatment decision-making

    NARCIS (Netherlands)

    Nuijten, Mark J. C.; Keller, Josbert J.; Visser, Caroline E.; Redekop, Ken; Claassen, Eric; Speelman, Peter; Pronk, Marja H.

    2015-01-01

    To develop a framework for the clinical and health economic assessment for management of Clostridium difficile infection (CDI). CDI has vast economic consequences emphasizing the need for innovative and cost effective solutions, which were aim of this study. A guidance model was developed for

  5. Review Clostridium difficile: A healthcare-associated infection of ...

    African Journals Online (AJOL)

    CDI is a healthcare-associated infection for which the primary risk factor is antibiotic usage, and it is the leading ... Three (of three) studies found an association with antibiotic usage. One (of four) ... prevalence and virulence of C. difficile in recent years.8-10 This ..... Changing trends in bacterial infections: Staphylococcus.

  6. Clostridium Difficile Infection Due to Pneumonia Treatment: Mortality Risk Models.

    Science.gov (United States)

    Chmielewska, M; Zycinska, K; Lenartowicz, B; Hadzik-Błaszczyk, M; Cieplak, M; Kur, Z; Wardyn, K A

    2017-01-01

    One of the most common gastrointestinal infection after the antibiotic treatment of community or nosocomial pneumonia is caused by the anaerobic spore Clostridium difficile (C. difficile). The aim of this study was to retrospectively assess mortality due to C. difficile infection (CDI) in patients treated for pneumonia. We identified 94 cases of post-pneumonia CDI out of the 217 patients with CDI. The mortality issue was addressed by creating a mortality risk models using logistic regression and multivariate fractional polynomial analysis. The patients' demographics, clinical features, and laboratory results were taken into consideration. To estimate the influence of the preceding respiratory infection, a pneumonia severity scale was included in the analysis. The analysis showed two statistically significant and clinically relevant mortality models. The model with the highest prognostic strength entailed age, leukocyte count, serum creatinine and urea concentration, hematocrit, coexisting neoplasia or chronic obstructive pulmonary disease. In conclusion, we report on two prognostic models, based on clinically relevant factors, which can be of help in predicting mortality risk in C. difficile infection, secondary to the antibiotic treatment of pneumonia. These models could be useful in preventive tailoring of individual therapy.

  7. Imipenem Resistance in Clostridium difficile Ribotype 017, Portugal

    Science.gov (United States)

    Isidro, Joana; Santos, Andrea; Nunes, Alexandra; Borges, Vítor; Silva, Catarina; Vieira, Luís; Mendes, Aristides L.; Serrano, Mónica; Henriques, Adriano O.; Gomes, João Paulo

    2018-01-01

    We describe imipenem-resistant and imipenem-susceptible clinical isolates of Clostridium difficile ribotype 017 in Portugal. All ribotype 017 isolates carried an extra penicillin-binding protein gene, pbp5, and the imipenem-resistant isolates had additional substitutions near the transpeptidase active sites of pbp1 and pbp3. These clones could disseminate and contribute to imipenem resistance. PMID:29553322

  8. Clostridium difficile infection in an endemic setting in the Netherlands

    NARCIS (Netherlands)

    Hensgens, M. P. M.; Goorhuis, A.; van Kinschot, C. M. J.; Crobach, M. J. T.; Harmanus, C.; Kuijper, E. J.

    2011-01-01

    The purpose of this investigation was to study risk factors for Clostridium difficile infection (CDI) in an endemic setting. In a 34-month prospective case-control study, we compared the risk factors and clinical characteristics of all consecutively diagnosed hospitalised CDI patients (n = 93) with

  9. A review of the economics of treating Clostridium difficile infection.

    Science.gov (United States)

    Mergenhagen, Kari A; Wojciechowski, Amy L; Paladino, Joseph A

    2014-07-01

    Clostridium difficile infection (CDI) is a costly result of antibiotic use, responsible for an estimated 14,000 deaths annually in the USA according to the Centers for Disease Control and Prevention. Annual costs attributable to CDI are in excess of $US 1 billion. This review summarizes appropriate utilization of prevention and treatment methods for CDI that have the potential to reduce the economic and humanistic costs of the disease. Some cost-effective strategies to prevent CDI include screening and isolation of hospital admissions based on C. difficile carriage to reduce transmission in the inpatient setting, and probiotics, which are potentially efficacious in preventing CDI in the appropriate patient population. The most extensively studied agents for treatment of CDI are metronidazole, vancomycin, and fidaxomicin. Most economic comparisons between metronidazole and vancomycin favor vancomycin, especially with the emergence of metronidazole-resistant C. difficile strains. Metronidazole can only be recommended for mild disease. Moderate to severe CDI should be treated with vancomycin, preferably the compounded oral solution, which provides the most cost-effective therapeutic option. Fidaxomicin offers a clinically effective and potentially cost-effective alternative for treating moderate CDI in patients who do not have the NAP1/BI/027 strain of C. difficile. Probiotics and fecal microbiota transplant have variable efficacy and the US FDA does not currently regulate the content; the potential economic advantages of these treatment modalities are currently unknown.

  10. The morbidity, mortality, and costs associated with Clostridium difficile infection.

    Science.gov (United States)

    Kwon, Jennie H; Olsen, Margaret A; Dubberke, Erik R

    2015-03-01

    Clostridium difficile infection (CDI) is the most common cause of infectious health care-associated diarrhea and is a major burden to patients and the health care system. The incidence and severity of CDI remain at historically high levels. This article reviews the morbidity, mortality, and costs associated with CDI. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Emerging therapies for Clostridium difficile infection – focus on fidaxomicin

    Directory of Open Access Journals (Sweden)

    Chaparro-Rojas F

    2013-06-01

    Full Text Available Fredy Chaparro-Rojas, Kathleen M MullaneDepartment of Medicine, Section of Infectious Diseases, University of Chicago, Chicago, IL, USAAbstract: The epidemiology of Clostridium difficile infections (CDI has evolved during the last decades, with an increase in the reported incidence, severity of cases, and rate of mortality and relapses. These increases have primarily affected some special populations including the elderly, patients requiring concomitant antibiotic therapy, patients with renal failure, and patients with cancer. Until recently, the treatment of CDI was limited to either metronidazole or vancomycin. New therapeutic options have emerged to address the shortcomings of current antibiotic therapy. Fidaxomicin stands out as the first-in-class oral macrocyclic antibiotic with targeted activity against C. difficile and minimal collateral damage on the normal colonic flora. Fidaxomicin has demonstrated performance not inferior to what is considered the “gold standard” available therapy for CDI, vancomycin, in two separate Phase III clinical trials, but with significant advantages, including fewer recurrences and higher rates of sustained clinical cures. Fidaxomicin constitutes an important development in targeted antibiotic therapy for CDI and must be considered as a first-line agent for patients with risk factors known to portend relapse and severe infection.Keywords: fidaxomicin, Clostridium difficile-associated diarrhea, CDAD, Clostridium difficile infection (CDI, vancomycin, metronidazole

  12. The structure of the S-layer of Clostridium difficile.

    Science.gov (United States)

    Bradshaw, William J; Roberts, April K; Shone, Clifford C; Acharya, K Ravi

    2018-03-01

    The nosocomially acquired pathogen Clostridium difficile is the primary causative agent of antibiotic associated diarrhoea and causes tens of thousands of deaths globally each year. C. difficile presents a paracrystalline protein array on the surface of the cell known as an S-layer. S-layers have been demonstrated to possess a wide range of important functions, which, combined with their inherent accessibility, makes them a promising drug target. The unusually complex S-layer of C. difficile is primarily comprised of the high- and low- molecular weight S-layer proteins, HMW SLP and LMW SLP, formed from the cleavage of the S-layer precursor protein, SlpA, but may also contain up to 28 SlpA paralogues. A model of how the S-layer functions as a whole is required if it is to be exploited in fighting the bacterium. Here, we provide a summary of what is known about the S-layer of C. difficile and each of the paralogues and, considering some of the domains present, suggest potential roles for them.

  13. Real-Time Electronic Tracking of Diarrheal Episodes and Laxative Therapy Enables Verification of Clostridium difficile Clinical Testing Criteria and Reduction of Clostridium difficile Infection Rates.

    Science.gov (United States)

    Truong, Cynthia Y; Gombar, Saurabh; Wilson, Richard; Sundararajan, Gopalakrishnan; Tekic, Natasa; Holubar, Marisa; Shepard, John; Madison, Alexandra; Tompkins, Lucy; Shah, Neil; Deresinski, Stan; Schroeder, Lee F; Banaei, Niaz

    2017-05-01

    Health care-onset health care facility-associated Clostridium difficile infection (HO-CDI) is overdiagnosed for several reasons, including the high prevalence of C. difficile colonization and the inability of hospitals to limit testing to patients with clinically significant diarrhea. We conducted a quasiexperimental study from 22 June 2015 to 30 June 2016 on consecutive inpatients with C. difficile test orders at an academic hospital. Real-time electronic patient data tracking was used by the laboratory to enforce testing criteria (defined as the presence of diarrhea [≥3 unformed stools in 24 h] and absence of laxative intake in the prior 48 h). Outcome measures included C. difficile test utilization, HO-CDI incidence, oral vancomycin utilization, and clinical complications. During the intervention, 7.1% (164) and 9.1% (211) of 2,321 C. difficile test orders were canceled due to absence of diarrhea and receipt of laxative therapy, respectively. C. difficile test utilization decreased upon implementation from an average of 208.8 tests to 143.0 tests per 10,000 patient-days ( P difficile results. Real-time electronic clinical data tracking is an effective tool for verification of C. difficile clinical testing criteria and safe reduction of inflated HO-CDI rates. Copyright © 2017 American Society for Microbiology.

  14. The toxins of Cyanobacteria.

    Science.gov (United States)

    Patocka, J

    2001-01-01

    Cyanobacteria, formerly called "blue-green algae", are simple, primitive photosynthetic microorganism wide occurrence in fresh, brackish and salt waters. Forty different genera of Cyanobacteria are known and many of them are producers of potent toxins responsible for a wide array of human illnesses, aquatic mammal and bird morbidity and mortality, and extensive fish kills. These cyanotoxins act as neurotoxins or hepatotoxins and are structurally and functionally diverse, and many are derived from unique biosynthetic pathways. All known cyanotoxins and their chemical and toxicological characteristics are presented in this article.

  15. Lymphocyte receptors for pertussis toxin

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.G.; Armstrong, G.D. (Univ. of Alberta, Edmonton (Canada))

    1990-12-01

    We have investigated human T-lymphocyte receptors for pertussis toxin by affinity isolation and photoaffinity labeling procedures. T lymphocytes were obtained from peripheral human blood, surface iodinated, and solubilized in Triton X-100. The iodinated mixture was then passed through pertussis toxin-agarose, and the fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography of the fixed, dried gels revealed several bands in the pertussis toxin-bound fraction that were not observed in fractions obtained from histone or fetuin-agarose. Further investigations employed a photoaffinity labeling reagent, sulfosuccinimidyl 2-(p-azido-salicylamido)-1,3'-dithiopropionate, to identify pertussis toxin receptors in freshly isolated peripheral blood monocytic cells, T lymphocytes, and Jurkat cells. In all three cell systems, the pertussis toxin affinity probe specifically labeled a single protein species with an apparent molecular weight of 70,000 that was not observed when the procedure was performed in the presence of excess unmodified pertussis toxin. A protein comparable in molecular weight to the one detected by the photoaffinity labeling technique was also observed among the species that bound to pertussis toxin-agarose. The results suggest that pertussis toxin may bind to a 70,000-Da receptor in human T lymphocytes.

  16. Botulinum toxin: bioweapon & magic drug.

    Science.gov (United States)

    Dhaked, Ram Kumar; Singh, Manglesh Kumar; Singh, Padma; Gupta, Pallavi

    2010-11-01

    Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal potency of botulinum toxin is enzymatic; the toxin is a zinc proteinase that cleaves neuronal vesicle associated proteins responsible for acetylcholine release into the neuromuscular junction. As a military or terrorist weapon, botulinum toxin could be disseminated via aerosol or by contamination of water or food supplies, causing widespread casualties. A fascinating aspect of botulinum toxin research in recent years has been development of the most potent toxin into a molecule of significant therapeutic utility . It is the first biological toxin which is licensed for treatment of human diseases. In the late 1980s, Canada approved use of the toxin to treat strabismus, in 2001 in the removal of facial wrinkles and in 2002, the FDA in the United States followed suit. The present review focuses on both warfare potential and medical uses of botulinum neurotoxin.

  17. Presence of Clostridium difficile in poultry and poultry meat in Egypt.

    Science.gov (United States)

    Abdel-Glil, Mostafa Y; Thomas, Prasad; Schmoock, Gernot; Abou-El-Azm, Kamel; Wieler, Lothar H; Neubauer, Heinrich; Seyboldt, Christian

    2018-06-01

    C. difficile has been recognized as a potential zoonotic agent encouraging investigations of C. difficile prevalence and ribotypes in animals. Here we report the prevalence and diversity of Egyptian C. difficile in I) samples from healthy poultry (n = 50), II) samples from diseased poultry (n = 54), and III) poultry meat (n = 150). Thirteen isolates were obtained from seven healthy and five diseased animals, but no C. difficile was cultured from poultry meat. The isolated C. difficile strains belonged to 3 different PCR-ribotypes (039/2, 205 and 001/FLI01). The detection of strains related to RT 001 known for its ability to cause disease in humans makes poultry a potential reservoir for pathogenic C. difficile. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Disruption of the Gut Microbiome: Clostridium difficile Infection and the Threat of Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Priscilla A. Johanesen

    2015-12-01

    Full Text Available Clostridium difficile is well recognized as the leading cause of antibiotic-associated diarrhea, having a significant impact in both health-care and community settings. Central to predisposition to C. difficile infection is disruption of the gut microbiome by antibiotics. Being a Gram-positive anaerobe, C. difficile is intrinsically resistant to a number of antibiotics. Mobile elements encoding antibiotic resistance determinants have also been characterized in this pathogen. While resistance to antibiotics currently used to treat C. difficile infection has not yet been detected, it may be only a matter of time before this occurs, as has been seen with other bacterial pathogens. This review will discuss C. difficile disease pathogenesis, the impact of antibiotic use on inducing disease susceptibility, and the role of antibiotic resistance and mobile elements in C. difficile epidemiology.

  19. Prevalence of Clostridium difficile in uncooked ground meat products from Pittsburgh, Pennsylvania.

    Science.gov (United States)

    Curry, Scott R; Marsh, Jane W; Schlackman, Jessica L; Harrison, Lee H

    2012-06-01

    The prevalence of Clostridium difficile in retail meat samples has varied widely. The food supply may be a source for C. difficile infections. A total of 102 ground meat and sausage samples from 3 grocers in Pittsburgh, PA, were cultured for C. difficile. Brand A pork sausages were resampled between May 2011 and January 2012. Two out of 102 (2.0%) meat products initially sampled were positive for C. difficile; both were pork sausage from brand A from the same processing facility (facility A). On subsequent sampling of brand A products, 10/19 samples from processing facility A and 1/10 samples from 3 other facilities were positive for C. difficile. The isolates recovered were inferred ribotype 078, comprising 6 genotypes. The prevalence of C. difficile in retail meat may not be as high as previously reported in North America. When contamination occurs, it may be related to events at processing facilities.

  20. Toxin-Based Therapeutic Approaches

    Directory of Open Access Journals (Sweden)

    Itai Benhar

    2010-10-01

    Full Text Available Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmaceutical potential of such toxins when they are used to efficiently impair essential cellular processes and/or damage the integrity of their target cells. The following review summarizes major advances in the field of toxin based therapeutics and offers a comprehensive description of the mode of action of each applied toxin.

  1. Toxin-Based Therapeutic Approaches

    Science.gov (United States)

    Shapira, Assaf; Benhar, Itai

    2010-01-01

    Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmaceutical potential of such toxins when they are used to efficiently impair essential cellular processes and/or damage the integrity of their target cells. The following review summarizes major advances in the field of toxin based therapeutics and offers a comprehensive description of the mode of action of each applied toxin. PMID:22069564

  2. Do piperacillin/tazobactam and other antibiotics with inhibitory activity against Clostridium difficile reduce the risk for acquisition of C. difficile colonization?

    Science.gov (United States)

    Kundrapu, Sirisha; Sunkesula, Venkata C K; Jury, Lucy A; Cadnum, Jennifer L; Nerandzic, Michelle M; Musuuza, Jackson S; Sethi, Ajay K; Donskey, Curtis J

    2016-04-18

    Systemic antibiotics vary widely in in vitro activity against Clostridium difficile. Some agents with activity against C. difficile (e.g., piperacillin/tazobactam) inhibit establishment of colonization in mice. We tested the hypothesis that piperacillin/tazobactam and other agents with activity against C. difficile achieve sufficient concentrations in the intestinal tract to inhibit colonization in patients. Point-prevalence culture surveys were conducted to compare the frequency of asymptomatic rectal carriage of toxigenic C. difficile among patients receiving piperacillin/tazobactam or other inhibitory antibiotics (e.g. ampicillin, linezolid, carbapenems) versus antibiotics lacking activity against C. difficile (e.g., cephalosporins, ciprofloxacin). For a subset of patients, in vitro inhibition of C. difficile (defined as a reduction in concentration after inoculation of vegetative C. difficile into fresh stool suspensions) was compared among antibiotic treatment groups. Of 250 patients, 32 (13 %) were asymptomatic carriers of C. difficile. In comparison to patients receiving non-inhibitory antibiotics or prior antibiotics within 90 days, patients currently receiving piperacillin/tazobactam were less likely to be asymptomatic carriers (1/36, 3 versus 7/36, 19 and 15/69, 22 %, respectively; P = 0.024) and more likely to have fecal suspensions with in vitro inhibitory activity against C. difficile (20/28, 71 versus 3/11, 27 and 4/26, 15 %; P = 0.03). Patients receiving other inhibitory antibiotics were not less likely to be asymptomatic carriers than those receiving non-inhibitory antibiotics. Our findings suggest that piperacillin/tazobactam achieves sufficient concentrations in the intestinal tract to inhibit C. difficile colonization during therapy.

  3. A Comprehensive Study of Costs Associated With Recurrent Clostridium difficile Infection.

    Science.gov (United States)

    Rodrigues, Rodrigo; Barber, Grant E; Ananthakrishnan, Ashwin N

    2017-02-01

    BACKGROUND Clostridium difficile infection (CDI) is the most common healthcare-associated infection and is associated with considerable morbidity. Recurrent CDI is a key contributing factor to this morbidity. Despite an estimated 83,000 recurrences annually in the United States, there are few accurate estimates of costs associated with recurrent CDI. OBJECTIVE We performed this study (1) to identify the health consequences of recurrent CDI including need for repeat hospitalization, intensive care unit (ICU) stay, and surgery; (2) to determine costs associated with recurrent CDI and identify determinants of such costs; and (3) to compare the outcomes and costs of recurrent CDI to those who develop reinfection. METHODS We identified all patients with confirmed recurrent CDI between January to December 2013 at a single referral center. Healthcare burden associated with recurrence including diagnostic testing, pharmacologic treatment, and inpatient and outpatient healthcare visits were identified in the 12 months following the first recurrence. Total healthcare costs were calculated, and the predictors of high healthcare utilization were identified. RESULTS Our study population included 98 patients with recurrent CDI. The median interval between the initial infection and recurrence was 37 days. The mean age of the cohort was 67 years, two-thirds were women (62%), and the mean Charlson index was 8.6. During the year following the first recurrence of CDI, each patient underwent a mean of 4.4 stool C. difficile toxin tests and received a mean of 2.5 prescriptions for oral vancomycin (range, 0-6). Most patients (84%) with recurrence had a CDI-related hospitalization, and 6% underwent colectomy. The mean total CDI-associated cost was $34,104 per patient, with hospitalization costs accounting for 68%, surgery 20%, and drug treatment 8% of this cost, respectively. Extrapolating to the United States overall, we estimate an annual cost of $2.8 billion related to recurrent CDI

  4. Bacteraemia and breast abscess: unusual extra-intestinal manifestations of Clostridium difficile infection.

    Science.gov (United States)

    Durojaiye, Oyewole; Gaur, Soma; Alsaffar, Layth

    2011-03-01

    Extra-intestinal manifestations of Clostridium difficile infection are uncommon. Most cases are associated with gastrointestinal disease and often occur as a mixed infection with other gut flora. We report a case of breast abscess following monomicrobial C. difficile bacteraemia in a female with background chronic hepatitis C infection and alcoholic liver disease. No evidence of colitis was found. Our case shows that C. difficile is indeed capable of spreading from the gastrointestinal tract.

  5. Prevalence and Genotypic Characteristics of Clostridium difficile in a Closed and Integrated Human and Swine Population▿

    OpenAIRE

    Norman, Keri N.; Scott, H. Morgan; Harvey, Roger B.; Norby, Bo; Hume, Michael E.; Andrews, Kathleen

    2011-01-01

    Recently, an apparent rise in the number of cases attributed to community-acquired Clostridium difficile infection has led researchers to explore additional sources of infection. The finding of C. difficile in food animals and retail meat has raised concern about potential food-borne and occupational exposures. The objective of this study was to compare C. difficile isolated from a closed population of healthy individuals consisting of both humans and swine in order to investigate possible fo...

  6. Routine disc diffusion antimicrobial susceptibility testing of Clostridium difficile and association with PCR ribotype 027

    DEFF Research Database (Denmark)

    Holt, H M; Danielsen, T K; Justesen, U S

    2015-01-01

    Reduced susceptibility to metronidazole and vancomycin in Clostridium difficile has been reported, which emphasises the need for simple antimicrobial susceptibility testing methods. The aim of this study was to apply a published disc diffusion method and zone diameter breakpoint correlates...... the published breakpoint (difficile PCR ribotype 027 isolates had smaller zone...... diameters than non-027 isolates. The disc diffusion method is very simple and inexpensive, and the published zone diameter breakpoints will detect C. difficile isolates with reduced susceptibility to metronidazole and vancomycin....

  7. European Society of Clinical Microbiology and Infectious Diseases: update of the diagnostic guidance document for Clostridium difficile infection.

    Science.gov (United States)

    Crobach, M J T; Planche, T; Eckert, C; Barbut, F; Terveer, E M; Dekkers, O M; Wilcox, M H; Kuijper, E J

    2016-08-01

    In 2009 the first European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline for diagnosing Clostridium difficile infection (CDI) was launched. Since then newer tests for diagnosing CDI have become available, especially nucleic acid amplification tests. The main objectives of this update of the guidance document are to summarize the currently available evidence concerning laboratory diagnosis of CDI and to formulate and revise recommendations to optimize CDI testing. This update is essential to improve the diagnosis of CDI and to improve uniformity in CDI diagnosis for surveillance purposes among Europe. An electronic search for literature concerning the laboratory diagnosis of CDI was performed. Studies evaluating a commercial laboratory test compared to a reference test were also included in a meta-analysis. The commercial tests that were evaluated included enzyme immunoassays (EIAs) detecting glutamate dehydrogenase, EIAs detecting toxins A and B and nucleic acid amplification tests. Recommendations were formulated by an executive committee, and the strength of recommendations and quality of evidence were graded using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. No single commercial test can be used as a stand-alone test for diagnosing CDI as a result of inadequate positive predictive values at low CDI prevalence. Therefore, the use of a two-step algorithm is recommended. Samples without free toxin detected by toxins A and B EIA but with positive glutamate dehydrogenase EIA, nucleic acid amplification test or toxigenic culture results need clinical evaluation to discern CDI from asymptomatic carriage. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Binding of ATP by pertussis toxin and isolated toxin subunits

    International Nuclear Information System (INIS)

    Hausman, S.Z.; Manclark, C.R.; Burns, D.L.

    1990-01-01

    The binding of ATP to pertussis toxin and its components, the A subunit and B oligomer, was investigated. Whereas, radiolabeled ATP bound to the B oligomer and pertussis toxin, no binding to the A subunit was observed. The binding of [ 3 H]ATP to pertussis toxin and the B oligomer was inhibited by nucleotides. The relative effectiveness of the nucleotides was shown to be ATP > GTP > CTP > TTP for pertussis toxin and ATP > GTP > TTP > CTP for the B oligomer. Phosphate ions inhibited the binding of [ 3 H]ATP to pertussis toxin in a competitive manner; however, the presence of phosphate ions was essential for binding of ATP to the B oligomer. The toxin substrate, NAD, did not affect the binding of [ 3 H]ATP to pertussis toxin, although the glycoprotein fetuin significantly decreased binding. These results suggest that the binding site for ATP is located on the B oligomer and is distinct from the enzymatically active site but may be located near the eukaryotic receptor binding site

  9. Binding of ATP by pertussis toxin and isolated toxin subunits

    Energy Technology Data Exchange (ETDEWEB)

    Hausman, S.Z.; Manclark, C.R.; Burns, D.L. (Center for Biologics Evaluation and Research, Bethesda, MD (USA))

    1990-07-03

    The binding of ATP to pertussis toxin and its components, the A subunit and B oligomer, was investigated. Whereas, radiolabeled ATP bound to the B oligomer and pertussis toxin, no binding to the A subunit was observed. The binding of ({sup 3}H)ATP to pertussis toxin and the B oligomer was inhibited by nucleotides. The relative effectiveness of the nucleotides was shown to be ATP > GTP > CTP > TTP for pertussis toxin and ATP > GTP > TTP > CTP for the B oligomer. Phosphate ions inhibited the binding of ({sup 3}H)ATP to pertussis toxin in a competitive manner; however, the presence of phosphate ions was essential for binding of ATP to the B oligomer. The toxin substrate, NAD, did not affect the binding of ({sup 3}H)ATP to pertussis toxin, although the glycoprotein fetuin significantly decreased binding. These results suggest that the binding site for ATP is located on the B oligomer and is distinct from the enzymatically active site but may be located near the eukaryotic receptor binding site.

  10. Antibiotic treatment for Clostridium difficile-associated diarrhea in adults.

    Science.gov (United States)

    Nelson, R

    2007-07-18

    Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhea and colitis. The aim of this review is to establish the efficacy of antibiotic therapy for C. difficile-associated diarrhea (CDAD), to identify the most effective antibiotic treatment for CDAD in adults and to determine the need for stopping the causative antibiotic during therapy. MEDLINE (1966 to 2006), EMBASE (1980 to 2006), Cochrane Central Database of Controlled Trials and the Cochrane IBD Review Group Specialized Trials Register were searched using the following search terms: "pseudomembranous colitis and randomized trial"; "Clostridium difficile and randomized trial"; "antibiotic associated diarrhea and randomized trial". Only randomized, controlled trials assessing antibiotic treatment for CDAD were included in the review. Probiotic trials are excluded. The following outcomes were sought: initial resolution of diarrhea; initial conversion of stool to C. difficile cytotoxin and/or stool culture negative; recurrence of diarrhea; recurrence of fecal C. difficile cytotoxin and/or positive stool culture; patient response to cessation of prior antibiotic therapy; sepsis; emergent surgery: fecal diversion or colectomy; and death. Data were analyzed using the MetaView statistical package in Review Manager. For dichotomous outcomes, relative risks (RR) and 95% confidence intervals (CI) were derived from each study. When appropriate, the results of included studies were combined for each outcome. For dichotomous outcomes, pooled RR and 95% CI were calculated using a fixed effect model, except where significant heterogeneity was detected, at which time the random effects model was used. Data heterogeneity was calculated using MetaView. Twelve studies (total of 1157 participants) involving patients with diarrhea who recently received antibiotics for an infection other than C. difficile were included. The definition of diarrhea ranged from at least two loose stools

  11. Clostridium difficile Infections: A Global Overview of Drug Sensitivity and Resistance Mechanisms

    Directory of Open Access Journals (Sweden)

    Saeed S. Banawas

    2018-01-01

    Full Text Available Clostridium difficile (C. difficile is the most prevalent causative pathogen of healthcare-associated diarrhea. Notably, over the past 10 years, the number of Clostridium difficile outbreaks has increased with the rate of morbidity and mortality. The occurrence and spread of C. difficile strains that are resistant to multiple antimicrobial drugs complicate prevention as well as potential treatment options. Most C. difficile isolates are still susceptible to metronidazole and vancomycin. Incidences of C. difficile resistance to other antimicrobial drugs have also been reported. Most of the antibiotics correlated with C. difficile infection (CDI, such as ampicillin, amoxicillin, cephalosporins, clindamycin, and fluoroquinolones, continue to be associated with the highest risk for CDI. Still, the detailed mechanism of resistance to metronidazole or vancomycin is not clear. Alternation in the target sites of the antibiotics is the main mechanism of erythromycin, fluoroquinolone, and rifamycin resistance in C. difficile. In this review, different antimicrobial agents are discussed and C. difficile resistance patterns and their mechanism of survival are summarized.

  12. Risk factors for Clostridium difficile infection in HIV-infected patients.

    Science.gov (United States)

    Imlay, Hannah; Kaul, Daniel; Rao, Krishna

    2016-01-01

    Clostridium difficile infection is a healthcare-associated infection resulting in significant morbidity. Although immunosuppression is associated with Clostridium difficile infection acquisition and adverse outcomes, the epidemiology of Clostridium difficile infection in HIV-infected patients has been little studied in the era of antiretroviral therapy. This study identifies the risk factors for acquisition of Clostridium difficile infection in HIV-infected patients. A retrospective, propensity score-matched case-control study design was employed, with patients selected from our institution's outpatient HIV clinic. Clostridium difficile infection cases were defined as having positive stool testing plus an appropriate clinical presentation. The propensity score was generated via multiple logistic regression from year of HIV diagnosis, age at first contact, duration of follow-up, gender, and initial CD4 count. The 46 cases included were matched to a total of 180 controls. Prior antibiotic treatment was a significant predictor of Clostridium difficile infection (odds ratio: 13, 95% confidence interval: 3.49-48.8, p  Clostridium difficile infection in the multivariable model (odds ratio: 15.17, confidence interval: 1.31-175.9, p  = .021). As in the general population, frequent hospitalizations and exposure to antimicrobials are independent predictors of Clostridium difficile infection acquisition in patients with HIV. Additionally, low CD4 count and proton pump inhibitor use are new potentially modifiable variables that can be targeted for prevention of Clostridium difficile infection in future interventional studies.

  13. Outcomes and Risk Factors Associated with Clostridium difficile Diarrhea in Hospitalized Adult Patients

    Directory of Open Access Journals (Sweden)

    Daniela Zilio Larentis

    2015-01-01

    Full Text Available Background. The epidemiology of Clostridium difficile infection has changed over time. Therefore, it is essential to monitor the characteristics of patients at risk of infection and factors associated with poor prognosis. Objective. To evaluate factors associated with C. difficile infection and with poor prognosis in those with documented C. difficile colitis. Methods. A retrospective case-control study of 75 patients with documented C. difficile colitis and 75 controls with hospital-acquired diarrhea of other causes. Stepwise multiple logistic regression was used to identify factors associated with C. difficile infection among patients with hospital-acquired diarrhea. Results. Previous antibiotic treatment (odds ratio (OR, 13.3; 95% confidence interval (CI, 1.40–126.90, abdominal distension (OR, 3.85; 95% CI, 1.35–10.98, and fecal leukocytes (OR, 8.79; 95% CI, 1.41–54.61 are considered as predictors of C. difficile colitis; anorexia was negatively associated with C. difficile infection (OR, 0.15; 95% CI, 0.03–0.66. Enteral tube feeding was independently associated with a composite outcome that included in-hospital mortality, intensive care unit admission, and treatment failure (OR, 3.75; 95%CI, 1.24–11.29. Conclusions. Previous antibiotic use and presence of fecal leukocytes in patients with hospital-acquired diarrhea are associated with C. difficile colitis and enteral tube support with complications associated with C. difficile colitis.

  14. PIP degron proteins, substrates of CRL4Cdt2, and not PIP boxes, interfere with DNA polymerase η and κ focus formation on UV damage

    OpenAIRE

    Tsanov, Nikolay; Kermi, Chames; Coulombe, Philippe; Van der Laan, Siem; Hodroj, Dana; Maiorano, Domenico

    2014-01-01

    Proliferating cell nuclear antigen (PCNA) is a well-known scaffold for many DNA replication and repair proteins, but how the switch between partners is regulated is currently unclear. Interaction with PCNA occurs via a domain known as a PCNA-Interacting Protein motif (PIP box). More recently, an additional specialized PIP box has been described, the « PIP degron », that targets PCNA-interacting proteins for proteasomal degradation via the E3 ubiquitin ligase CRL4Cdt2. Here we provide evidence...

  15. Length of stay and hospital costs among high-risk patients with hospital-origin Clostridium difficile-associated diarrhea.

    Science.gov (United States)

    Campbell, Rebecca; Dean, Bonnie; Nathanson, Brian; Haidar, Tracy; Strauss, Marcie; Thomas, Sheila

    2013-01-01

    Hospital-onset Clostridium difficile-associated diarrhea (HO-CDAD) has been associated with longer length of stay (LOS) and higher hospital costs among patients in general. The burden of HO-CDAD is unknown among patients who may be at particular risk of poor outcomes: older patients, those with complex or chronic conditions (renal disease, cancer, inflammatory bowel disease [IBD]), and those with concomitant antibiotic (CAbx) use during treatment for CDAD. A retrospective analysis (2005-2011) of the Health Facts® database (Cerner Corp., Kansas City, MO) containing comprehensive clinical records from 186 US hospitals identified hospitalized adult patients with HO-CDAD based on a positive C. difficile toxin collected >48 h after admission. Control patients were required to have total hospital LOS ≥2 days. Separate logistic regression models to estimate propensities were developed for each study group, with HO-CDAD vs controls as the outcome. Differences in LOS and costs were calculated between cases and controls for each group. A total of 4521 patients with HO-CDAD were identified. Mean age was 70 years, 54% were female, and 13% died. After matching, LOS was significantly greater among HO-CDAD patients (vs controls) in each group except IBD. The significant difference in LOS ranged from 3.0 (95% CI = 1.4-4.6) additional days in older patients to 7.8 (95% CI = 5.7-9.9) days in patients with CAbx exposure. HO-CDAD was associated with significantly higher costs among older patients (p cost data and potential misclassification of colonized patients as infected. Renal impairment, advanced age, cancer, and CAbx use are associated with significantly longer LOS among HO-CDAD patients, with CAbx users being the most resource intensive. Early identification and aggressive treatment of HO-CDAD in these groups may be warranted.

  16. Economic burden of Clostridium difficile associated diarrhoea: a cost-of-illness study from a German tertiary care hospital.

    Science.gov (United States)

    Heimann, S M; Vehreschild, J J; Cornely, O A; Wisplinghoff, H; Hallek, M; Goldbrunner, R; Böttiger, B W; Goeser, T; Hölscher, A; Baldus, S; Müller, F; Jazmati, N; Wingen, S; Franke, B; Vehreschild, M J G T

    2015-12-01

    Clostridium difficile associated diarrhoea (CDAD) is the most common cause of health-care-associated infectious diarrhoea. In the context of the German health-care system, direct and indirect costs of an initial episode of CDAD and of CDAD recurrence are currently unknown. We defined CDAD as presence of diarrhoea (≥3 unformed stools/day) in association with detection of Clostridium difficile toxin in an unformed faecal sample. Patients treated with metronidazole (PO or IV) and/or vancomycin (PO) were included. Comprehensive data of patients were retrospectively documented into a database using the technology of the Cologne Cohort of Neutropenic Patients (CoCoNut). Patients with CDAD were matched to control patients in a 1:1 ratio. Analysis was split in three groups: incidence group (CDAD patients without recurrence), recurrence group (CDAD patients with ≥1 recurrence) and control group (matched non-CDAD patients). Between 02/2010 and 12/2011, 150 patients with CDAD (114 patients in the incidence and 36 (24 %) in the recurrence group) and 150 controls were analysed. Mean length of stay was: 32 (95 %CI: 30-37), 94 (95 %CI: 76-112) and 24 days (95 %CI: 22-27; P = costs per patient of €18,460 (95 %CI: €14,660-€22,270), €73,900 (95 %CI: €50,340-€97,460) and €14,530 (95 %CI: €11,730-€17,330; P = costs, which were mostly attributable to a significantly longer overall length of stay. Innovative treatment strategies are warranted to reduce treatment costs and prevent recurrence of CDAD.

  17. Clostridium difficile outbreak caused by NAP1/BI/027 strain and non-027 strains in a Mexican hospital

    Directory of Open Access Journals (Sweden)

    Rayo Morfin-Otero

    2016-01-01

    Conclusions: C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance of C. difficile infections is now part of our nosocomial prevention program.

  18. Food toxin detection with atomic force microscope

    Science.gov (United States)

    Externally introduced toxins or internal spoilage correlated pathogens and their metabolites are all potential sources of food toxins. To prevent and protect unsafe food, many food toxin detection techniques have been developed to detect various toxins for quality control. Although several routine m...

  19. Botulinum Toxin (Botox) for Facial Wrinkles

    Science.gov (United States)

    ... Stories Español Eye Health / Eye Health A-Z Botulinum Toxin (Botox) for Facial Wrinkles Sections Botulinum Toxin (Botox) ... Facial Wrinkles How Does Botulinum Toxin (Botox) Work? Botulinum Toxin (Botox) for Facial Wrinkles Leer en Español: La ...

  20. The importance of matrix-assisted laser desorption ionization–time of flight mass spectrometry for correct identification of Clostridium difficile isolated from chromID C. difficile chromogenic agar

    Directory of Open Access Journals (Sweden)

    Jonathan H.K. Chen

    2017-10-01

    Full Text Available The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.

  1. Studies for the application of Boron neutron capture therapy (BNCT) to the treatment of differentiated thyroid cancer (CDT)

    International Nuclear Information System (INIS)

    Carpano, Marina; Thomasz, Lisa; Perona, Marina; Juvenal, Guillermo J.; Pisarev, Mario; Dagrosa, Maria A.; Nievas, Susana I.; Pozzi, Emiliano; Thorp, Silvia

    2009-01-01

    Boron neutron capture therapy (BNCT) is a high linear energy transfer (LET) radiotherapy for cancer, which it is based on the nuclear reaction that occurs when boron-10 that it is a non radioactive isotope of the natural elemental boron, is irradiated with low energy thermal neutrons to produce an alpha particle and a nucleus of lithium-7. Both particles have a range smaller than the diameter of a cell causing cell tumor death without significant damage to the surrounding normal tissues. In previous studies we have shown that BNCT can be a possibility for the treatment of undifferentiated thyroid cancer (UTC). However, more than 80 % of patients with thyroid neoplasm present differentiated carcinoma (CDT). These carcinomas are treated by surgery followed by therapy with 131 I and mostly these forms are well controlled. But in some patients recurrence of the tumor is observed. BNCT can be an alternative for these patients in who the tumor lost the capacity to concentrate iodide. The aim of these studies was to evaluate the possibility of treating differentiated thyroid cancer by BNCT. Materials and Methods: The human cell lines of follicular (WRO) and papillary carcinomas (TPC-1) were grown in RPMI and modified DMEM medium respectively. Both supplemented with 10 % of SFB. The cell line of thyroid rat, FRTL-5, used as control normal, was cultured in DMEM/F12. The uptakes of 125 I and p-borophenylalanine BPA (6.93mM) were studied. The intracellular boron concentration was measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) at 2 hr post incubation. The NIH strain of male nude mice, aged 6 to 8 weeks and weighing 20 to 25 g were implanted (s.c) in the back right flank with different concentrations of tumor cells. The size of the tumors was measured with a caliper twice or three times a week and the volume was calculated according the following formulae: A 2 x B/2 (were A is the width and B is the length). To evaluate the BPA uptake, animals

  2. Bacillus coagulans GBI-30, 6086 limits the recurrence of Clostridium difficile-Induced colitis following vancomycin withdrawal in mice

    OpenAIRE

    Fitzpatrick, Leo R; Small, Jeffrey S; Greene, Wallace H; Karpa, Kelly D; Farmer, Sean; Keller, David

    2012-01-01

    Abstract Background Recently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC30) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 104...

  3. Examination of Clostridium difficile Contamination in beef meat distributed in Isfahan using culture and Multiplex-PCR method

    OpenAIRE

    zahra Esfandiari; Mohammad Jalali; Hamid Ezzatpanah; Scott Weese; Mohammad Chamani

    2014-01-01

    Introduction: With regard to increasing of community associated Clostridium difficile infection in recent years, the probable transmission of Clostridium difficile from food to human was supposed. Most of reports on this issue were allocated to examine the prevalence of Clostridium difficile in red meat. The current study aimed at examination of the prevalence of Clostridium difficile in beef meat. Materials and methods: A total of 100 beef meat samples includi...

  4. Disparate subcellular location of putative sortase substrates in Clostridium difficile.

    Science.gov (United States)

    Peltier, Johann; Shaw, Helen A; Wren, Brendan W; Fairweather, Neil F

    2017-08-23

    Clostridium difficile is a gastrointestinal pathogen but how the bacterium colonises this niche is still little understood. Sortase enzymes covalently attach specific bacterial proteins to the peptidoglycan cell wall and are often involved in colonisation by pathogens. Here we show C. difficile proteins CD2537 and CD3392 are functional substrates of sortase SrtB. Through manipulation of the C-terminal regions of these proteins we show the SPKTG motif is essential for covalent attachment to the cell wall. Two additional putative substrates, CD0183 which contains an SPSTG motif, and CD2768 which contains an SPQTG motif, are not cleaved or anchored to the cell wall by sortase. Finally, using an in vivo asymmetric cleavage assay, we show that despite containing a conserved SPKTG motif, in the absence of SrtB these proteins are localised to disparate cellular compartments.

  5. A simulation-based assessment of strategies to control Clostridium difficile transmission and infection.

    Directory of Open Access Journals (Sweden)

    Michael A Rubin

    Full Text Available BACKGROUND: Clostridium difficile is one of the most common and important nosocomial pathogens, causing severe gastrointestinal disease in hospitalized patients. Although "bundled" interventions have been proposed and promoted, optimal control strategies remain unknown. METHODS: We designed an agent-based computer simulation of nosocomial C. difficile transmission and infection, which included components such as: patients and health care workers, and their interactions; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. We then introduced six interventions, alone and "bundled" together: aggressive C. difficile testing; empiric isolation and treatment of symptomatic patients; improved adherence to hand hygiene and contact precautions; improved use of soap and water for hand hygiene; and improved environmental cleaning. All interventions were tested using values representing base-case, typical intervention, and optimal intervention scenarios. FINDINGS: In the base-case scenario, C. difficile infection rates ranged from 8-21 cases/10,000 patient-days, with a case detection fraction between 32%-50%. Implementing the "bundle" at typical intervention levels had a large impact on C. difficile acquisition and infection rates, although intensifying the intervention to optimal levels had much less additional impact. Most of the impact came from improved hand hygiene and empiric isolation and treatment of suspected C. difficile cases. CONCLUSION: A "bundled" intervention is likely to reduce nosocomial C. difficile infection rates, even under typical implementation conditions. Real-world implementation of the "bundle" should focus on those components of the intervention that are likely to produce the greatest impact on C. difficile infection rates, such as hand hygiene and empiric

  6. Costs of Clostridium difficile infection in pediatric operations: A propensity score-matching analysis.

    Science.gov (United States)

    Kulaylat, Afif N; Rocourt, Dorothy V; Podany, Abigail B; Engbrecht, Brett W; Twilley, Marianne; Santos, Mary C; Cilley, Robert E; Hollenbeak, Christopher S; Dillon, Peter W

    2017-05-01

    The purpose of this analysis was to assess the burden of Clostridium difficile infection in the hospitalized pediatric surgical population and to characterize its influence on the costs of care. There were 313,664 patients age 1-18 years who underwent a general thoracic or abdominal procedure in the Kids' Inpatient Database during 2003, 2006, 2009, and 2012. Logistic regression was used to model factors associated with the development of C difficile infection. A propensity score-matching analysis was performed to evaluate the influence of C difficile infection on mortality, duration of stay, and costs in similar patient cohorts. Population weights were used to estimate the national excess burden of C difficile infection on these outcomes. The overall prevalence of C difficile infection in the sampled cohort was 0.30%, with an increasing trend of C difficile infection over time in non-children's hospitals (P difficile infection was associated with younger age, nonelective procedures, increasing comorbidities, and urban teaching hospital status (P difficile infection after operation. After propensity score matching, the mean excess duration of stay and costs attributable to C difficile infection were 5.8 days and $12,801 (P difficile infection is a relatively uncommon but costly complication after pediatric operative procedures. Given the increasing trend of C difficile infection among hospitalized surgical patients, there is substantial opportunity for reduction of inpatient burden and associated costs in this potentially preventable nosocomial infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Bio Warfare and Terrorism: Toxins and Other Mid-Spectrum Agents

    National Research Council Canada - National Science Library

    Madsen, James M

    2005-01-01

    ... counterparts are still by definition toxins. Related terms include phycotoxins (toxins from algae), mycotoxins (fungal toxins), phytotoxins (plant toxins), and venoms (toxins from animals, especially vertebrates...

  8. Clostridium difficile from food and surface samples in a Belgian nursing home: an unlikely source of contamination.

    Science.gov (United States)

    Rodriguez, C; Korsak, N; Taminiau, B; Avesani, V; Van Broeck, J; Brach, P; Delmée, M; Daube, G

    2015-04-01

    This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Oscillating behavior of Clostridium difficile Min proteins in Bacillus subtilis.

    Science.gov (United States)

    Makroczyová, Jana; Jamroškovič, Ján; Krascsenitsová, Eva; Labajová, Nad'a; Barák, Imrich

    2016-06-01

    In rod-shaped bacteria, the proper placement of the division septum at the midcell relies, at least partially, on the proteins of the Min system as an inhibitor of cell division. The main principle of Min system function involves the formation of an inhibitor gradient along the cell axis; however, the establishment of this gradient differs between two well-studied gram-negative and gram-positive bacteria. While in gram-negative Escherichia coli, the Min system undergoes pole-to-pole oscillation, in gram-positive Bacillus subtilis, proper spatial inhibition is achieved by the preferential attraction of the Min proteins to the cell poles. Nevertheless, when E.coli Min proteins are inserted into B.subtilis cells, they still oscillate, which negatively affects asymmetric septation during sporulation in this organism. Interestingly, homologs of both Min systems were found to be present in various combinations in the genomes of anaerobic and endospore-forming Clostridia, including the pathogenic Clostridium difficile. Here, we have investigated the localization and behavior of C.difficile Min protein homologs and showed that MinDE proteins of C.difficile can oscillate when expressed together in B.subtilis cells. We have also investigated the effects of this oscillation on B.subtilis sporulation, and observed decreased sporulation efficiency in strains harboring the MinDE genes. Additionally, we have evaluated the effects of C.difficile Min protein expression on vegetative division in this heterologous host. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  10. DNA microarray-based PCR ribotyping of Clostridium difficile.

    Science.gov (United States)

    Schneeberg, Alexander; Ehricht, Ralf; Slickers, Peter; Baier, Vico; Neubauer, Heinrich; Zimmermann, Stefan; Rabold, Denise; Lübke-Becker, Antina; Seyboldt, Christian

    2015-02-01

    This study presents a DNA microarray-based assay for fast and simple PCR ribotyping of Clostridium difficile strains. Hybridization probes were designed to query the modularly structured intergenic spacer region (ISR), which is also the template for conventional and PCR ribotyping with subsequent capillary gel electrophoresis (seq-PCR) ribotyping. The probes were derived from sequences available in GenBank as well as from theoretical ISR module combinations. A database of reference hybridization patterns was set up from a collection of 142 well-characterized C. difficile isolates representing 48 seq-PCR ribotypes. The reference hybridization patterns calculated by the arithmetic mean were compared using a similarity matrix analysis. The 48 investigated seq-PCR ribotypes revealed 27 array profiles that were clearly distinguishable. The most frequent human-pathogenic ribotypes 001, 014/020, 027, and 078/126 were discriminated by the microarray. C. difficile strains related to 078/126 (033, 045/FLI01, 078, 126, 126/FLI01, 413, 413/FLI01, 598, 620, 652, and 660) and 014/020 (014, 020, and 449) showed similar hybridization patterns, confirming their genetic relatedness, which was previously reported. A panel of 50 C. difficile field isolates was tested by seq-PCR ribotyping and the DNA microarray-based assay in parallel. Taking into account that the current version of the microarray does not discriminate some closely related seq-PCR ribotypes, all isolates were typed correctly. Moreover, seq-PCR ribotypes without reference profiles available in the database (ribotype 009 and 5 new types) were correctly recognized as new ribotypes, confirming the performance and expansion potential of the microarray. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Clostridium difficile infections in patients with severe burns

    Science.gov (United States)

    2011-01-01

    placards indicating that hand hygiene should involve soap and water. Periodic hand hygiene compliance surveys have indicated relatively consistent...care unit: epidemiology, costs, and colonization pressure. Infect Control Hosp Epidemiol 2007;28:123–30. [6] Marcon AP, Gamba MA, Vianna LA. Nosocomial ...Clostridium difficile infections in patients with severe burns§ Scott J. Crabtree a, Janelle L. Robertson a,b, Kevin K. Chung c, Evan M. Renz b,c

  12. Clostridium difficile-associated diarrhoea in infants and children

    OpenAIRE

    Vuletić Biljana; Ristanović Elizabeta; Marković Slavica; Rašković Zorica; Radlović Vladimir; Igrutinović Zoran

    2017-01-01

    Clostridium difficile (CD) is the most common cause of nosocomial diarrhea in adults with high rates of morbidity and mortality. The epidemiology of CD infection (CDI) has changed in the last few decades associated with increasing severity of the infection rate related to the occurrence of NAP1 hypervirulent strain and the emergence of the disease among ambulatory patients and the wider community. Although little is known about CDI in pediatric patients, CD is surprisingly recognized as an im...

  13. Established and potential risk factors for clostridum difficile infection

    Directory of Open Access Journals (Sweden)

    Vaishnavi C

    2009-01-01

    Full Text Available Clostridium difficile is the aetiological agent for almost all cases of pseudo membranous colitis and 15-25% of antibiotic associated diarrhoea. In recent years, C. difficile associated disease (CDAD has been increasing in frequency and severity due to the emergence of virulent strains. Severe cases of toxic mega colon may be associated with mortality rates of 24-38%. The prevalence of CDAD is global and the incidence varies considerably from place to place. In the initial stages of its discovery, C. difficile infection was regarded mainly as an outcome of antibiotic intake and not as a life threatening disease. Intervention by man has produced conditions making C. difficile a significant cause of morbidity and mortality. The recent outbreak of CDAD in Quebec has sent the alarm bells ringing. Apart from a threefold increase in the incidence of CDAD, clinicians have also reported a higher number of cases involving toxic mega colon, colectomy or death. Among all the risk factors, inclusive of the host and the environmental factors, antibiotics are the most important ones. Surgical patients comprise 55-75% of all patients with CDAD due to the fact that perioperative prophylaxis requires the use of antibiotics. However, other drugs such as immunosuppressants and proton pump inhibitors are also important risk factors. Thus CDAD is a growing nosocomial and public health challenge. Additionally, the recognition of community acquired CDAD signals the presence of several risk factors. In this review, the established and potential risk factors of CDAD, along with the epidemiology, diagnostic modalities, management and preventive measures of the disease have been elaborated.

  14. Economic evaluation of interventions designed to reduce Clostridium difficile infection.

    Science.gov (United States)

    Brain, David; Yakob, Laith; Barnett, Adrian; Riley, Thomas; Clements, Archie; Halton, Kate; Graves, Nicholas

    2018-01-01

    Healthcare decision-makers are increasingly expected to balance increasing demand for health services with a finite budget. The role of economic evaluation in healthcare is increasing and this research provides decision-makers with new information about the management of Clostridium difficile infection, from an economic perspective. A model-based economic evaluation was undertaken to identify the most cost-effective healthcare intervention relating to the reduction of Clostridium difficile transmission. Efficacy evidence was synthesised from the literature and was used to inform the effectiveness of both bundled approaches and stand-alone interventions, where appropriate intervention combinations were coupled together. Changes in health outcomes were estimated by combining information about intervention effectiveness and its subsequent impact on quality of life. A bundled approach of improving hand hygiene and environmental cleaning produces the best combination of increased health benefits and cost-savings. It has the highest mean net monetary benefit when compared to all other interventions. This intervention remains the optimal decision under different clinical circumstances, such as when mortality rate and patient length of stay are increased. Bundled interventions offered the best opportunity for health improvements. These findings provide healthcare decision-makers with novel information about the allocation of scarce resources relating to Clostridium difficile. If investments are not made in interventions that clearly yield gains in health outcomes, the allocation and use of scarce healthcare resources is inappropriate and improvements in health outcomes will be forgone.

  15. Economic evaluation of interventions designed to reduce Clostridium difficile infection.

    Directory of Open Access Journals (Sweden)

    David Brain

    Full Text Available Healthcare decision-makers are increasingly expected to balance increasing demand for health services with a finite budget. The role of economic evaluation in healthcare is increasing and this research provides decision-makers with new information about the management of Clostridium difficile infection, from an economic perspective.A model-based economic evaluation was undertaken to identify the most cost-effective healthcare intervention relating to the reduction of Clostridium difficile transmission. Efficacy evidence was synthesised from the literature and was used to inform the effectiveness of both bundled approaches and stand-alone interventions, where appropriate intervention combinations were coupled together. Changes in health outcomes were estimated by combining information about intervention effectiveness and its subsequent impact on quality of life.A bundled approach of improving hand hygiene and environmental cleaning produces the best combination of increased health benefits and cost-savings. It has the highest mean net monetary benefit when compared to all other interventions. This intervention remains the optimal decision under different clinical circumstances, such as when mortality rate and patient length of stay are increased. Bundled interventions offered the best opportunity for health improvements.These findings provide healthcare decision-makers with novel information about the allocation of scarce resources relating to Clostridium difficile. If investments are not made in interventions that clearly yield gains in health outcomes, the allocation and use of scarce healthcare resources is inappropriate and improvements in health outcomes will be forgone.

  16. Fidaxomicin - the new drug for Clostridium difficile infection

    Directory of Open Access Journals (Sweden)

    Chetana Vaishnavi

    2015-01-01

    Full Text Available Clostridium difficile is one of the many aetiological agents of antibiotic associated diarrhoea and is implicated in 15-25 per cent of the cases. The organism is also involved in the exacearbation of inflammatory bowel disease and extracolonic manifestations. Due to increase in the incidence of C. difficile infection (CDI, emergence of hypervirulent strains, and increased frequency of recurrence, the clinical management of the disease has become important. The management of CDI is based on disease severity, and current antibiotic treatment options are limited to vancomycin or metronidazole in the developing countries. this review article briefly describes important aspects of CDI, and the new drug, fidaxomicin, for its treatment. Fidaxomicin is particularly active against C.difficile and acts by inhibition of RNA synthesis. Clinical trials done to compare the efficacy and safety of fidaxomicin with that of vancomycin in treating CDI concluded that fidaxomicin was non-inferior to vancomycin for treatment of CDI and that there was a significant reduction in recurrences. The bactericidal properties of fidaxomicin make it an ideal alternative for CDI treatment. However, fidaxomicin use should be considered taking into account the potential benefits of the drug, along with the medical requirements of the patient, the risks of treatment and the high cost of fidaxomicin compared to other treatment regimens.

  17. SEVERE CLOSTRIDIUM DIFFICILE INFECTIONS. A SYSTEMATIC LITERATURE -review-

    Directory of Open Access Journals (Sweden)

    Adriana Elena NICA

    2016-06-01

    Full Text Available Clostridium difficile is a bacterium that has been brought to the attention of the medical community recently, as the number of infections related to it has increased dramatically. This is happening mainly because of the excessive and defective use of antibiotic therapy. The pathology of a Clostridium Difficile infection is very complex, as it ranges from easy symptoms like abdominal pain and diarrhea to severe complications, like toxic megacolon. The management of these infections has become even more difficult, as they are not appearing only in the hospital environment anymore, but also outside of it. The bacterium spreads through poor hands hygiene. Also, we don’t have a clear strategy for overcoming an infection like this, so it gets even more difficult as most of the times the doctors need to rely only on their experience and knowledge to find ways of battling it. We would like to underline the research opportunities that are available in this domain as very few things are known about Clostridium difficile and also the crucial importance of research, as these infections are common and dangerous not only for patients, but for the medical staff and their families too.

  18. Botulinum toxin in trigeminal neuralgia.

    Science.gov (United States)

    Castillo-Álvarez, Federico; Hernando de la Bárcena, Ignacio; Marzo-Sola, María Eugenia

    2017-01-06

    Trigeminal neuralgia is one of the most disabling facial pain syndromes, with a significant impact on patients' quality of life. Pharmacotherapy is the first choice for treatment but cases of drug resistance often require new strategies, among which various interventional treatments have been used. In recent years a new therapeutic strategy consisting of botulinum toxin has emerged, with promising results. We reviewed clinical cases and case series, open-label studies and randomized clinical trials examining the use of botulinum toxin for drug-refractory trigeminal neuralgia published in the literature. The administration of botulinum toxin has proven to be a safe and effective therapeutic strategy in patients with drug-refractory idiopathic trigeminal neuralgia, but many questions remain unanswered as to the precise role of botulinum toxin in the treatment of this disease. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  19. Toxin-Based Therapeutic Approaches

    OpenAIRE

    Itai Benhar; Assaf Shapira

    2010-01-01

    Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmac...

  20. Antimicrobial Resistance and Reduced Susceptibility in Clostridium difficile: Potential Consequences for Induction, Treatment, and Recurrence of C. difficile Infection

    Science.gov (United States)

    Baines, Simon D.; Wilcox, Mark H.

    2015-01-01

    Clostridium difficile infection (CDI) remains a substantial burden on healthcare systems and is likely to remain so given our reliance on antimicrobial therapies to treat bacterial infections, especially in an aging population in whom multiple co-morbidities are common. Antimicrobial agents are a key component in the aetiology of CDI, both in the establishment of the infection and also in its treatment. The purpose of this review is to summarise the role of antimicrobial agents in primary and recurrent CDI; assessing why certain antimicrobial classes may predispose to the induction of CDI according to a balance between antimicrobial activity against the gut microflora and C. difficile. Considering these aspects of CDI is important in both the prevention of the infection and in the development of new antimicrobial treatments. PMID:27025625

  1. Hospital-based Clostridium difficile infection surveillance reveals high proportions of PCR ribotypes 027 and 176 in different areas of Poland, 2011 to 2013.

    Science.gov (United States)

    Pituch, Hanna; Obuch-Woszczatyński, Piotr; Lachowicz, Dominika; Wultańska, Dorota; Karpiński, Paweł; Młynarczyk, Grażyna; van Dorp, Sofie M; Kuijper, Ed J

    2015-01-01

    As part of the European Clostridium difficile infections (CDI) surveillance Network (ECDIS-Net), which aims to build capacity for CDI surveillance in Europe, we constructed a new network of hospital-based laboratories in Poland. We performed a survey in 13 randomly selected hospital-laboratories in different sites of the country to determine their annual CDI incidence rates from 2011 to 2013. Information on C. difficile laboratory diagnostic testing and indications for testing was also collected. Moreover, for 2012 and 2013 respectively, participating hospital-laboratories sent all consecutive isolates from CDI patients between February and March to the Anaerobe Laboratory in Warsaw for further molecular characterisation, including the detection of toxin-encoding genes and polymerase chain reaction (PCR)-ribotyping. Within the network, the mean annual hospital CDI incidence rates were 6.1, 8.6 and 9.6 CDI per 10,000 patient-days in 2011, 2012, and 2013 respectively. Six of the 13 laboratories tested specimens only on the request of a physician, five tested samples of antibiotic-associated diarrhoea or samples from patients who developed diarrhoea more than two days after admission (nosocomial diarrhoea), while two tested all submitted diarrhoeal faecal samples. Most laboratories (9/13) used tests to detect glutamate dehydrogenase and toxin A/B either separately or in combination. In the two periods of molecular surveillance, a total of 166 strains were characterised. Of these, 159 were toxigenic and the majority belonged to two PCR-ribotypes: 027 (n=99; 62%) and the closely related ribotype 176 (n=22; 14%). The annual frequency of PCR-ribotype 027 was not significantly different during the surveillance periods (62.9% in 2012; 61.8% in 2013). Our results indicate that CDIs caused by PCR-ribotype 027 predominate in Polish hospitals participating in the surveillance, with the closely related 176 ribotype being the second most common agent of infection.

  2. Dysfunctional families: Clostridium scindens and secondary bile acids inhibit the growth of Clostridium difficile.

    Science.gov (United States)

    Greathouse, K Leigh; Harris, Curtis C; Bultman, Scott J

    2015-01-06

    C. difficile infection is a deadly disease that is influenced by the microbiome. In a recent article in Nature, Buffie et al. (2014) demonstrate that the ability of C. scindens to synthesize secondary bile acids is crucial to providing resistance to C. difficile infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Prevention of Clostridium difficile Infection with Saccharomyces boulardii: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Jennifer M Tung

    2009-01-01

    Full Text Available BACKGROUND: Clostridium difficile is a major cause of antibioticassociated diarrhea within the hospital setting. The yeast Saccharomyces boulardii has been found to have some effect in reducing the risk of C difficile infection (CDI; however, its role in preventive therapy has yet to be firmly established.

  4. The epidemiology and economic burden of Clostridium difficile infection in Korea.

    Science.gov (United States)

    Choi, Hyung-Yun; Park, So-Youn; Kim, Young-Ae; Yoon, Tai-Young; Choi, Joong-Myung; Choe, Bong-Keun; Ahn, So-Hee; Yoon, Seok-Jun; Lee, Ye-Rin; Oh, In-Hwan

    2015-01-01

    The prevalence of Clostridium difficile infection and the associated burden have recently increased in many countries. While the main risk factors for C. difficile infection include old age and antibiotic use, the prevalence of this infection is increasing in low-risk groups. These trends highlight the need for research on C. difficile infection. This study pointed out the prevalence and economic burden of C. difficile infection and uses the representative national data which is primarily from the database of the Korean Health Insurance Review and Assessment Service, for 2008-2011. The annual economic cost was measured using a prevalence approach, which sums the costs incurred to treat C. difficile infection. C. difficile infection prevalence was estimated to have increased from 1.43 per 100,000 in 2008 to 5.06 per 100,000 in 2011. Moreover, mortality increased from 69 cases in 2008 to 172 in 2011. The economic cost increased concurrently, from $2.4 million in 2008 to $7.6 million, $10.5 million, and $15.8 million in 2009, 2010, and 2011, respectively. The increasing economic burden of C. difficile infection over the course of the study period emphasizes the need for intervention to minimize the burden of a preventable illness like C. difficile infection.

  5. The Epidemiology and Economic Burden of Clostridium difficile Infection in Korea

    Directory of Open Access Journals (Sweden)

    Hyung-Yun Choi

    2015-01-01

    Full Text Available The prevalence of Clostridium difficile infection and the associated burden have recently increased in many countries. While the main risk factors for C. difficile infection include old age and antibiotic use, the prevalence of this infection is increasing in low-risk groups. These trends highlight the need for research on C. difficile infection. This study pointed out the prevalence and economic burden of C. difficile infection and uses the representative national data which is primarily from the database of the Korean Health Insurance Review and Assessment Service, for 2008–2011. The annual economic cost was measured using a prevalence approach, which sums the costs incurred to treat C. difficile infection. C. difficile infection prevalence was estimated to have increased from 1.43 per 100,000 in 2008 to 5.06 per 100,000 in 2011. Moreover, mortality increased from 69 cases in 2008 to 172 in 2011. The economic cost increased concurrently, from $2.4 million in 2008 to $7.6 million, $10.5 million, and $15.8 million in 2009, 2010, and 2011, respectively. The increasing economic burden of C. difficile infection over the course of the study period emphasizes the need for intervention to minimize the burden of a preventable illness like C. difficile infection.

  6. Epidemiology of Clostridium difficile: a hospital-based descriptive study in Argentina and Mexico

    Directory of Open Access Journals (Sweden)

    Gustavo Lopardo

    2015-01-01

    Full Text Available A prospective study was conducted in four tertiary hospitals in Argentina and Mexico in order to describe the occurrence of Clostridium difficile infection (CDI in these settings. The objective was to evaluate the incidence of CDI in at-risk populations in Argentina (one center and Mexico (three centers and to further explore potential study sites for vaccine development in this region. A prospective, descriptive, CDI surveillance study was conducted among hospitalized patients aged ≥40 years who had received ≥48 h of antibiotic treatment. Stool samples were collected from those with diarrhea within 30 days after starting antibiotics and analyzed for toxins A and B by ELISA, and positive samples were further tested by toxinogenic culture and restriction endonuclease analysis type assay. Overall, 466 patients were enrolled (193 in Argentina and 273 in Mexico of whom 414 completed the follow-up. Of these, 15/414 (3.6% experienced CDI episodes occurring on average 18.1 days after admission to hospital and 15.9 days after the end of antibiotics treatment. The incidence rate of CDI was 3.1 (95% CI 1.7–5.2 per 1000 patient-days during hospitalization, and 1.1 (95% CI 0.6–1.8 per 1000 patient-days during the 30-day follow-up period. This study highlighted the need for further evaluation of the burden of CDI in both countries, including the cases occurring after discharge from hospital.

  7. A hospital-level cost-effectiveness analysis model for toxigenic Clostridium difficile detection algorithms.

    Science.gov (United States)

    Verhoye, E; Vandecandelaere, P; De Beenhouwer, H; Coppens, G; Cartuyvels, R; Van den Abeele, A; Frans, J; Laffut, W

    2015-10-01

    Despite thorough analyses of the analytical performance of Clostridium difficile tests and test algorithms, the financial impact at hospital level has not been well described. Such a model should take institution-specific variables into account, such as incidence, request behaviour and infection control policies. To calculate the total hospital costs of different test algorithms, accounting for days on which infected patients with toxigenic strains were not isolated and therefore posed an infectious risk for new/secondary nosocomial infections. A mathematical algorithm was developed to gather the above parameters using data from seven Flemish hospital laboratories (Bilulu Microbiology Study Group) (number of tests, local prevalence and hospital hygiene measures). Measures of sensitivity and specificity for the evaluated tests were taken from the literature. List prices and costs of assays were provided by the manufacturer or the institutions. The calculated cost included reagent costs, personnel costs and the financial burden following due and undue isolations and antibiotic therapies. Five different test algorithms were compared. A dynamic calculation model was constructed to evaluate the cost:benefit ratio of each algorithm for a set of institution- and time-dependent inputted variables (prevalence, cost fluctuations and test performances), making it possible to choose the most advantageous algorithm for its setting. A two-step test algorithm with concomitant glutamate dehydrogenase and toxin testing, followed by a rapid molecular assay was found to be the most cost-effective algorithm. This enabled resolution of almost all cases on the day of arrival, minimizing the number of unnecessary or missing isolations. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  8. The incidence of Clostridioides difficile and Clostridium perfringens netF-positive strains in diarrheic dogs.

    Science.gov (United States)

    Diniz, Amanda Nadia; Coura, Fernanda Morcatti; Rupnik, Maja; Adams, Vicki; Stent, Thomas L; Rood, Julian I; de Oliveira, Carlos Augusto; Lobato, Francisco Carlos Faria; Silva, Rodrigo Otávio Silveira

    2018-02-01

    The aim of this study was to examine the incidence of Clostridioides (previously Clostridium) difficile and Clostridium perfringens in the feces of diarrheic and non-diarrheic dogs. Also, the presence of other common canine enteropathogens was examined. Toxigenic C. difficile and C. perfringens positive for the NetF-encoding gene (netF) were detected in 11 (11.9%) and seven (7.6%) diarrheic dogs, respectively. Three dogs were diagnosed simultaneously with toxigenic C. difficile and netF-positive C. perfringens. Among other enteropathogens, Giardia sp. was the most common agent detected in dogs positive for toxigenic C. difficile or netF-positive C. perfringens. The results suggest that C. difficile and C. perfringens occur more frequently as a primary cause of diarrhea. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Coinfection and Emergence of Rifamycin Resistance during a Recurrent Clostridium difficile Infection.

    Science.gov (United States)

    Stevenson, Emma C; Major, Giles A; Spiller, Robin C; Kuehne, Sarah A; Minton, Nigel P

    2016-11-01

    Clostridium difficile (Peptoclostridium difficile) is a common health care-associated infection with a disproportionately high incidence in elderly patients. Disease symptoms range from mild diarrhea to life-threatening pseudomembranous colitis. Around 20% of patients may suffer recurrent disease, which often requires rehospitalization of patients. C. difficile was isolated from stool samples from a patient with two recurrent C. difficile infections. PCR ribotyping, whole-genome sequencing, and phenotypic assays were used to characterize these isolates. Genotypic and phenotypic screening of C. difficile isolates revealed multiple PCR ribotypes present and the emergence of rifamycin resistance during the infection cycle. Understanding both the clinical and bacterial factors that contribute to the course of recurrent infection could inform strategies to reduce recurrence. (This study has been registered at ClinicalTrials.gov under registration no. NCT01670149.). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Increasing seroprevalence of Clostridium difficile in an adult Danish general population

    DEFF Research Database (Denmark)

    Fenger, R V; Linneberg, A; Tvede, M

    2009-01-01

    The incidence of Clostridium difficile-associated infections is increasing, but it remains to be defined whether any change in the seroprevalence of C. difficile has also occurred. In a population-based study of the general adult population, 734 subjects, aged 15-69 years, were examined on two...... occasions 8 years apart (1990 and 1998) for the presence of antibodies against C. difficile in serum. The overall seroprevalence of C. difficile increased significantly from 19% in 1990 to 27% in 1998 (P... was about four times higher in 1998 than in 1990. In conclusion, the observed increase in seroprevalence suggests a higher exposure to C. difficile in the general Danish adult population....

  11. Determining the cause of recurrent Clostridium difficile infection using whole genome sequencing.

    Science.gov (United States)

    Sim, James Heng Chiak; Truong, Cynthia; Minot, Samuel S; Greenfield, Nick; Budvytiene, Indre; Lohith, Akshar; Anikst, Victoria; Pourmand, Nader; Banaei, Niaz

    2017-01-01

    Understanding the contribution of relapse and reinfection to recurrent Clostridium difficile infection (CDI) has implications for therapy and infection prevention, respectively. We used whole genome sequencing to determine the relation of C. difficile strains isolated from patients with recurrent CDI at an academic medical center in the United States. Thirty-five toxigenic C. difficile isolates from 16 patients with 19 recurrent CDI episodes with median time of 53.5days (range, 13-362) between episodes were whole genome sequenced on the Illumina MiSeq platform. In 84% (16) of recurrences, the cause of recurrence was relapse with prior strain of C. difficile. In 16% (3) of recurrent episodes, reinfection with a new strain of C. difficile was the cause. In conclusion, the majority of CDI recurrences at our institution were due to infection with the same strain rather than infection with a new strain. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Epidemiology and outcome of Clostridium difficile infections in patients hospitalized in Internal Medicine: findings from the nationwide FADOI-PRACTICE study

    Directory of Open Access Journals (Sweden)

    Giorgio Cioni

    2016-11-01

    Full Text Available Abstract Background Clostridium difficile (CD is a leading cause of diarrhoea among hospitalized patients. The objective of this study was to evaluate the rate, the optimal diagnostic work-up, and outcome of CD infections (CDI in Internal Medicine (IM wards in Italy. Methods PRACTICE is an observational prospective study, involving 40 IM Units and evaluating all consecutive patients hospitalized during a 4-month period. CDI were defined in case of diarrhoea when both enzyme immunoassay for GDH, and test for A/B toxin were positive. Patients with CDI were followed-up for recurrences for 4 weeks after the end of therapy. Results Among the 10,780 patients observed, 103 (0.96 % showed CDI, at admission or during hospitalization. A positive history for CD, antibiotics in the previous 4 weeks, recent hospitalization, female gender and age were significantly associated with CDI (multivariable analysis. In-hospital mortality was 16.5 % in CD group vs 6.7 % in No-CD group (p < 0.001, whereas median length of hospital stay was 16 (IQR = 13 vs 8 (IQR = 8 days (p < 0.001 among patients with or without CDI, respectively. Rate of CD recurrences was 14.6 %. As a post-hoc evaluation, 23 out of 34 GDH+/Tox- samples were toxin positive, when analysed by molecular method (a real-time PCR assay. The overall CD incidence rate was 5.3/10,000 patient-days. Conclusions Our results confirm the severity of CDI in medical wards, showing high in-hospital mortality, prolonged hospitalization and frequent short-term recurrences. Further, our survey supports a 2–3 step algorithm for CD diagnosis: EIA for detecting GDH, A and B toxin, followed by a molecular method in case of toxin-negative samples.

  13. Botulinum toxin in pain treatment.

    Science.gov (United States)

    Colhado, Orlando Carlos Gomes; Boeing, Marcelo; Ortega, Luciano Bornia

    2009-01-01

    Botulinum toxin (BTX) is one of the most potent bacterial toxins known and its effectiveness in the treatment of some pain syndromes is well known. However, the efficacy of some of its indications is still in the process of being confirmed. The objective of this study was to review the history, pharmacological properties, and clinical applications of BTX in the treatment of pain of different origins. Botulinum toxin is produced by fermentation of Clostridium botulinum, a Gram-positive, anaerobic bacterium. Commercially, BTX comes in two presentations, types A and B. Botulinum toxin, a neurotoxin with high affinity for cholinergic synapses, blocks the release of acetylcholine by nerve endings without interfering with neuronal conduction of electrical signals or synthesis and storage of acetylcholine. It has been proven that BTX can selectively weaken painful muscles, interrupting the spasm-pain cycle. Several studies have demonstrated the efficacy and safety of BTX-A in the treatment of tension headaches, migraines, chronic lumbar pain, and myofascial pain. Botulinum toxin type A is well tolerated in the treatment of chronic pain disorders in which pharmacotherapy regimens can cause side effects. The reduction in the consumption of analgesics and length of action of 3 to 4 months per dose represent other advantages of its use. However, further studies are necessary to establish the efficacy of BTX-A in chronic pain disorders and its exact mechanism of action, as well as its potential in multifactorial treatments.

  14. The utility of repeat enzyme immunoassay testing for the diagnosis of Clostridium difficile infection: A systematic review of the literature

    Directory of Open Access Journals (Sweden)

    P S Garimella

    2012-01-01

    Full Text Available Over the last 20 years, the prevalence of healthcare-associated Clostridium difficile (C. diff disease has increased. While multiple tests are available for the diagnosis of C. diff infection, enzyme immunoassay (EIA testing for toxin is the most used. Repeat EIA testing, although of limited utility, is common in medical practice. To assess the utility of repeat EIA testing to diagnose C. diff infections. Systematic literature review. Eligible studies performed >1 EIA test for C. diff toxin and were published in English. Electronic searches of MEDLINE and EMBASE were performed and bibliographies of review articles and conference abstracts were hand searched. Of 805 citations identified, 32 were reviewed in detail and nine were included in the final review. All studies except one were retrospective chart reviews. Seven studies had data on number of participants (32,526, and the overall reporting of test setting and patient characteristics was poor. The prevalence of C. diff infection ranged from 9.1% to 18.5%. The yield of the first EIA test ranged from 8.4% to 16.6%, dropping to 1.5-4.7% with a second test. The utility of repeat testing was evident in outbreak settings, where the yield of repeat testing was 5%. Repeat C. diff testing for hospitalized patients has low clinical utility and may be considered in outbreak settings or when the pre-test probability of disease is high. Future studies should aim to identify patients with a likelihood of disease and determine the utility of repeat testing compared with empiric treatment.

  15. Structural insight into the Clostridium difficile ethanolamine utilisation microcompartment.

    Directory of Open Access Journals (Sweden)

    Alison C Pitts

    Full Text Available Bacterial microcompartments form a protective proteinaceous barrier around metabolic enzymes that process unstable or toxic chemical intermediates. The genome of the virulent, multidrug-resistant Clostridium difficile 630 strain contains an operon, eut, encoding a bacterial microcompartment with genes for the breakdown of ethanolamine and its utilisation as a source of reduced nitrogen and carbon. The C. difficile eut operon displays regulatory genetic elements and protein encoding regions in common with homologous loci found in the genomes of other bacteria, including the enteric pathogens Salmonella enterica and Enterococcus faecalis. The crystal structures of two microcompartment shell proteins, CD1908 and CD1918, and an uncharacterised protein with potential enzymatic activity, CD1925, were determined by X-ray crystallography. CD1908 and CD1918 display the same protein fold, though the order of secondary structure elements is permuted in CD1908 and this protein displays an N-terminal β-strand extension. These proteins form hexamers with molecules related by crystallographic and non-crystallographic symmetry. The structure of CD1925 has a cupin β-barrel fold and a putative active site that is distinct from the metal-ion dependent catalytic cupins. Thin-section transmission electron microscopy of Escherichia coli over-expressing eut proteins indicates that CD1918 is capable of self-association into arrays, suggesting an organisational role for CD1918 in the formation of this microcompartment. The work presented provides the basis for further study of the architecture and function of the C. difficile eut microcompartment, its role in metabolism and the wider consequences of intestinal colonisation and virulence in this pathogen.

  16. Entry of Shiga toxin into cells

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; van Deurs, Bo

    1994-01-01

    Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport......Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport...

  17. Inhibition of cholera toxin and other AB toxins by polyphenolic compounds

    Science.gov (United States)

    All AB-type protein toxins have intracellular targets despite an initial extracellular location. These toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against AB toxins are therefore hard to develop because the toxins use dif...

  18. Function of the CRISPR-Cas System of the Human Pathogen Clostridium difficile

    Science.gov (United States)

    Boudry, Pierre; Semenova, Ekaterina; Monot, Marc; Datsenko, Kirill A.; Lopatina, Anna; Sekulovic, Ognjen; Ospina-Bedoya, Maicol; Fortier, Louis-Charles; Severinov, Konstantin; Dupuy, Bruno

    2015-01-01

    ABSTRACT Clostridium difficile is the cause of most frequently occurring nosocomial diarrhea worldwide. As an enteropathogen, C. difficile must be exposed to multiple exogenous genetic elements in bacteriophage-rich gut communities. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems allow bacteria to adapt to foreign genetic invaders. Our recent data revealed active expression and processing of CRISPR RNAs from multiple type I-B CRISPR arrays in C. difficile reference strain 630. Here, we demonstrate active expression of CRISPR arrays in strain R20291, an epidemic C. difficile strain. Through genome sequencing and host range analysis of several new C. difficile phages and plasmid conjugation experiments, we provide evidence of defensive function of the CRISPR-Cas system in both C. difficile strains. We further demonstrate that C. difficile Cas proteins are capable of interference in a heterologous host, Escherichia coli. These data set the stage for mechanistic and physiological analyses of CRISPR-Cas-mediated interactions of important global human pathogen with its genetic parasites. PMID:26330515

  19. The Ecology and Pathobiology of Clostridium difficile Infections: An Interdisciplinary Challenge

    Science.gov (United States)

    Dubberke, Erik R.; Haslam, David B.; Lanzas, Cristina; Bobo, Linda D.; Burnham, Carey-Ann D.; Gröhn, Yrjö T.; Tarr, Phillip I.

    2013-01-01

    Summary Clostridium difficile is a well recognized pathogen of humans and animals. Although C. difficile was first identified over 70 years ago, much remains unknown in regards to the primary source of human acquisition and its pathobiology. These deficits in our knowledge have been intensified by dramatic increases in both the frequency and severity of disease in humans over the last decade. The changes in C. difficile epidemiology might be due to the emergence of a hypervirulent stain of C. difficile, aging of the population, altered risk of developing infection with newer medications, and/or increased exposure to C. difficile outside of hospitals. In recent years there have been numerous reports documenting C. difficile contamination of various foods, and reports of similarities between strains that infect animals and strains that infect humans as well. The purposes of this review are to highlight the many challenges to diagnosing, treating, and preventing C. difficile infection in humans, and to stress that collaboration between human and veterinary researchers is needed to control this pathogen. PMID:21223531

  20. Probiotics for the treatment of Clostridium difficile associated disease

    OpenAIRE

    Fitzpatrick, Leo R

    2013-01-01

    The purpose of this review paper is to update the current and potential future role of probiotics for Clostridium difficile-associated disease (CDAD). Included in this review, is an update on the testing of newer probiotics (e.g., Bacillus coagulans GBI-30, 6086) in animal models of CDAD. There is a focus on the modulation of signal transduction pathways (i.e., transcription factors like cAMP response element-binding, activator protein 1, and nuclear factor kappa B), as well as the inhibition...

  1. Probiotics and Antibiotic-Associated Diarrhea and Clostridium difficile Infection

    Science.gov (United States)

    Surawicz, Christina M.

    Diarrhea is a common side effect of antibiotics. Antibiotics can cause diarrhea in 5-25% of individuals who take them but its occurrence is unpredictable. Diarrhea due to antibiotics is called antibiotic-associated diarrhea (AAD). Diarrhea may be mild and resolve when antibiotics are discontinued, or it may be more severe. The most severe form of AAD is caused by overgrowth of Clostridium difficile which can cause severe diarrhea, colitis, pseudomembranous colitis, or even fatal toxic megacolon. Rates of diarrhea vary with the specific antibiotic as well as with the individual susceptibility.

  2. Toxin synergism in snake venoms

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard

    2016-01-01

    Synergism between venom toxins exists for a range of snake species. Synergism can be derived from both intermolecular interactions and supramolecular interactions between venom components, and can be the result of toxins targeting the same protein, biochemical pathway or physiological process. Few...... simple systematic tools and methods for determining the presence of synergism exist, but include co-administration of venom components and assessment of Accumulated Toxicity Scores. A better understanding of how to investigate synergism in snake venoms may help unravel strategies for developing novel...

  3. The Incidence of Nosocomial Toxigenic Clostridium difficile Associated Diarrhea in Tehran Tertiary Medical Centers

    Directory of Open Access Journals (Sweden)

    Norakhoda Sadeghifard

    2010-09-01

    Full Text Available "nClostridium difficile is the most common cause of nosocomial diarrhea. It is usually a consequence of antibiotic treatment, But sporadic cases can occur. This study was aimed to determine the frequency of the nosocomial Clostridium difficile (C. difficile associated diarrhea in Tehran University of Medical Sciences hospitals and study of antibacterial susceptibility of isolates. In this study a total of 942 stool samples from patients with nosocomial diarrhea that were hospitalized in Imam Khomeini hospital, Shariati hospital and Children clinical center were collected. The samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA and incubated in anaerobic conditions, at 37°C for 5 days. Isolates were characterized to species level by conventional biochemical tests. Bacterial cytotoxicity was assayed on tissue culture (vero. Antimicrobial sensitivity of isolated toxigenic C. difficile were investigated by kirby Beuer method (disk diffusion. Our findings show that, of the total patients, 57 toxigenic C. difficile (6.1% were isolated. Results of statistical analysis show significant differences between the rate of isolated toxigenic C. difficile and age group of patients (P<0.05. Among the wards of selected hospitals, in gastroenterology of Children clinical center, Toxigenic C. difficile was isolated from patients most frequently. The sensitivity of isolates to vancomycin, Chloramphenicol and ceftriaxone were higher than other antibiotics. Toxigenic C. difficile is a common hospital-acquired infection. The organism was found in 6.1% hospitalized patients. Further studies to evaluate the rate and role of toxigenic C. difficile in nosocomial diarrheal processes, ecological and pathogenic terms are suggested.

  4. A Clostridium difficile alanine racemase affects spore germination and accommodates serine as a substrate.

    Science.gov (United States)

    Shrestha, Ritu; Lockless, Steve W; Sorg, Joseph A

    2017-06-23

    Clostridium difficile has become one of the most common bacterial pathogens in hospital-acquired infections in the United States. Although C. difficile is strictly anaerobic, it survives in aerobic environments and transmits between hosts via spores. C. difficile spore germination is triggered in response to certain bile acids and glycine. Although glycine is the most effective co-germinant, other amino acids can substitute with varying efficiencies. Of these, l-alanine is an effective co-germinant and is also a germinant for most bacterial spores. Many endospore-forming bacteria embed alanine racemases into their spore coats, and these enzymes are thought to convert the l-alanine germinant into d-alanine, a spore germination inhibitor. Although the C. difficile Alr2 racemase is the sixth most highly expressed gene during C. difficile spore formation, a previous study reported that Alr2 has little to no role in germination of C. difficile spores in rich medium. Here, we hypothesized that Alr2 could affect C. difficile l-alanine-induced spore germination in a defined medium. We found that alr2 mutant spores more readily germinate in response to l-alanine as a co-germinant. Surprisingly, d-alanine also functioned as a co-germinant. Moreover, we found that Alr2 could interconvert l- and d-serine and that Alr2 bound to l- and d-serine with ∼2-fold weaker affinity to that of l- and d-alanine. Finally, we demonstrate that l- and d-serine are also co-germinants for C. difficile spores. These results suggest that C. difficile spores can respond to a diverse set of amino acid co-germinants and reveal that Alr2 can accommodate serine as a substrate. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Evaluation of a Chromogenic Culture Medium for Isolation of Clostridium difficile within 24 Hours ▿

    Science.gov (United States)

    Perry, John D.; Asir, Kerry; Halimi, Diane; Orenga, Sylvain; Dale, Joanne; Payne, Michelle; Carlton, Ruth; Evans, Jim; Gould, F. Kate

    2010-01-01

    Rapid and effective methods for the isolation of Clostridium difficile from stool samples are desirable to obtain isolates for typing or to facilitate accurate diagnosis of C. difficile-associated diarrhea. We report on the evaluation of a prototype chromogenic medium (ID C. difficile prototype [IDCd]) for isolation of C. difficile. The chromogenic medium was compared using (i) 368 untreated stool samples that were also inoculated onto CLO medium, (ii) 339 stool samples that were subjected to alcohol shock and also inoculated onto five distinct selective agars, and (iii) standardized suspensions of 10 C. difficile ribotypes (untreated and alcohol treated) that were also inoculated onto five distinct selective agars. Two hundred thirty-six isolates of C. difficile were recovered from 368 untreated stool samples, and all but 1 of these strains (99.6%) were recovered on IDCd within 24 h, whereas 74.6% of isolates were recovered on CLO medium after 48 h. Of 339 alcohol-treated stool samples cultured onto IDCd and five other selective agars, C. difficile was recovered from 218 samples using a combination of all media. The use of IDCd allowed recovery of 96.3% of isolates within 24 h, whereas 51 to 83% of isolates were recovered within 24 h using the five other media. Finally, when they were challenged with pure cultures, all 10 ribotypes of C. difficile generated higher colony counts on IDCd irrespective of alcohol pretreatment or duration of incubation. We conclude that IDCd is an effective medium for isolation of C. difficile from stool samples within 24 h. PMID:20739493

  6. A case of multiple recurrence of Clostridium difficile infection with severe hematochezia in an immunocompromised host.

    Science.gov (United States)

    Zhang, Xuewu; Chen, Yunbo; Gu, Silan; Zheng, Beiwen; Lv, Tao; Lou, Yinjun; Jin, Jie

    2016-12-01

    Clostridium difficile infection (CDI) is increasing in incidence and severity. Clinically, diarrhea frequently occurs, but severe hematochezia is rarely seen with CDI. We describe here a hematopoietic stem cell transplantation (HSCT) recipient who experienced life-threatening gastrointestinal bleeding due to severe CDI. Subsequent stool surveillance and molecular typing observed the patient who had two episodes of recurrence with a new strain of C. difficile distinct from the initial infection. We analyze C. difficile strains obtained from the patient, and also discuss the diagnosis and treatment of this case. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Fæcestransplantation som behandling af Clostridium difficile-infektion, colitis ulcerosa og metabolisk syndrom

    DEFF Research Database (Denmark)

    Carstensen, Jeppe West; Hansen, Axel Kornerup

    2014-01-01

    Faecal transplantation as a treatment for Clostridium difficile infection, ulcerative colitis and the metabolic syndrome Faecal transplantation as a therapeutic tool is increasingly reported in the scientific literature. Faecal transplantation is currently becoming a treatment for nosocomial......, refractory infections with C. difficile. Furthermore, faecal transplantation has been suggested as a treatment for ulcerative colitis as well as for the metabolic syndrome. In the accumulated literature faecal transplantations appear to be safe, effective and superior to current treatments. Faecal...... transplantation remains a sparsely investigated treatment, however, especially for other diagnoses than C. difficile infection....

  8. [Environmental toxins in breast milk].

    Science.gov (United States)

    Bratlid, Dag

    2009-12-17

    Breast milk is very important to ensure infants a well-composed and safe diet during the first year of life. However, the quality of breast milk seems to be affected by an increasing amount of environmental toxins (particularly so-called Persistent, Bioaccumulative Toxins [PBTs]). Many concerns have been raised about the negative effects this may have on infant health. The article is a review of literature (mainly review articles) identified through a non-systematic search in PubMed. The concentration of PBTs in breast milk is mainly caused by man's position as the terminal link in the nutritional chain. Many breast-fed infants have a daily intake of such toxins that exceed limits defined for the population in general. Animal studies demonstrate effects on endocrine function and neurotoxicity in the offspring, and a number of human studies seem to point in the same direction. However the "original" optimal composition of breast milk still seems to protect against long-term effects of such toxicity. There is international consensus about the need to monitor breast milk for the presence of PBTs. Such surveillance will be a good indicator of the population's general exposure to these toxins and may also contribute to identifying groups as risk who should not breast-feed their children for a long time.

  9. Risk Assessment of Shellfish Toxins

    Directory of Open Access Journals (Sweden)

    Rex Munday

    2013-11-01

    Full Text Available Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved.

  10. Food irradiation and bacterial toxins

    International Nuclear Information System (INIS)

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-01-01

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods. (author)

  11. Botulinum toxin for vaginismus treatment.

    Science.gov (United States)

    Ferreira, Juliana Rocha; Souza, Renan Pedra

    2012-01-01

    Vaginismus is characterized by recurrent or persistent involuntary contraction of the perineal muscles surrounding the outer third of the vagina when penile, finger, tampon, or speculum penetration is attempted. Recent results have suggested the use of botulinum toxin for the treatment of vaginismus. Here, we assessed previously published data to evaluate the therapeutic effectiveness of botulinum toxin for vaginismus. We have carried out a systematic review followed by a meta-analysis. Our results indicate that botulinum toxin is an effective therapeutic option for patients with vaginismus (pooled odds ratio of 8.723 with 95% confidence interval limits of 1.942 and 39.162, p = 0.005). This may hold particularly true in treatment-refractory patients because most of the studies included in this meta-analysis have enrolled these subjects in their primary analysis. Botulinum toxin appears to bea reasonable intervention for vaginismus. However, this conclusion should be read carefully because of the deficiency of placebo-controlled randomized clinical trials and the quality issues presented in the existing ones.

  12. Shigella Sonnei and Shiga Toxin

    Centers for Disease Control (CDC) Podcasts

    2016-07-28

    Katherine Lamba, an infectious disease epidemiologist with the California Department of Public Health, discusses Shiga Toxin producing Shigella sonnei.  Created: 7/28/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/28/2016.

  13. Point-prevalence survey of healthcare facility-onset healthcare-associated Clostridium difficile infection in Greek hospitals outside the intensive care unit: The C. DEFINE study.

    Science.gov (United States)

    Skoutelis, Athanasios; Pefanis, Angelos; Tsiodras, Sotirios; Sipsas, Nikolaos V; Lelekis, Moyssis; Lazanas, Marios C; Gargalianos, Panagiotis; Dalekos, George N; Roilides, Emmanuel; Samonis, George; Maltezos, Efstratios; Hatzigeorgiou, Dimitrios; Lada, Malvina; Metallidis, Symeon; Stoupis, Athena; Chrysos, Georgios; Karnesis, Lazaros; Symbardi, Styliani; Loupa, Chariclia V; Giamarellou, Helen; Kioumis, Ioannis; Sambatakou, Helen; Tsianos, Epameinondas; Kotsopoulou, Maria; Georgopali, Areti; Liakou, Klairi; Perlorentzou, Stavroula; Levidiotou, Stamatina; Giotsa-Toutouza, Marina; Tsorlini-Christoforidou, Helen; Karaiskos, Ilias; Kouppari, Georgia; Trikka-Graphakos, Eleftheria; Ntrivala, Maria-Anna; Themeli-Digalaki, Kate; Pangalis, Anastasia; Kachrimanidou, Melina; Martsoukou, Maria; Karapsias, Stergios; Panopoulou, Maria; Maraki, Sofia; Orfanou, Anagnostina; Petinaki, Efthymia; Orfanidou, Maria; Baka, Vasiliki; Stylianakis, Antonios; Spiliopoulou, Iris; Smilakou, Stavroula; Zerva, Loukia; Vogiatzakis, Evangelos; Belesiotou, Eleni; Gogos, Charalambos A

    2017-01-01

    The correlation of Clostridium difficile infection (CDI) with in-hospital morbidity is important in hospital settings where broad-spectrum antimicrobial agents are routinely used, such as in Greece. The C. DEFINE study aimed to assess point-prevalence of CDI in Greece during two study periods in 2013. There were two study periods consisting of a single day in March and another in October 2013. Stool samples from all patients hospitalized outside the ICU aged ≥18 years old with diarrhea on each day in 21 and 25 hospitals, respectively, were tested for CDI. Samples were tested for the presence of glutamate dehydrogenase antigen (GDH) and toxins A/B of C. difficile; samples positive for GDH and negative for toxins were further tested by culture and PCR for the presence of toxin genes. An analysis was performed to identify potential risk factors for CDI among patients with diarrhea. 5,536 and 6,523 patients were screened during the first and second study periods, respectively. The respective point-prevalence of CDI in all patients was 5.6 and 3.9 per 10,000 patient bed-days whereas the proportion of CDI among patients with diarrhea was 17% and 14.3%. Logistic regression analysis revealed that solid tumor malignancy [odds ratio (OR) 2.69, 95% confidence interval (CI): 1.18-6.15, p = 0.019] and antimicrobial administration (OR 3.61, 95% CI: 1.03-12.76, p = 0.045) were independent risk factors for CDI development. Charlson's Comorbidity Index (CCI) >6 was also found as a risk factor of marginal statistical significance (OR 2.24, 95% CI: 0.98-5.10). Median time to CDI from hospital admission was shorter with the presence of solid tumor malignancy (3 vs 5 days; p = 0.002) and of CCI >6 (4 vs 6 days, p = 0.009). The point-prevalence of CDI in Greek hospitals was consistent among cases of diarrhea over a 6-month period. Major risk factors were antimicrobial use, solid tumor malignancy and a CCI score >6.

  14. Management of Clostridium difficile in a developing nation

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    Azadeh Nasrollah

    2016-01-01

    Full Text Available Introduction: Clostridium difficile is the most important definable cause of healthcare acquired diarrhea. Recommended treatments for Clostridium difficile infection (CDI are metronidazole, oral vancomycin and fidaxomicin (a new narrow spectrum macrocyclic antibiotic. Aim: The aim of this investigation was to review the treatment of CDI in Iran. Method: 1600 medical records and prescriptions were scrutinized for patients complaining of diarrhea, colitis and gastroenteritis. The therapeutic route was investigated in each individual case bearing in mind the medical and medication history as well as other co-morbidities. Results: The selection of antibiotic by many medical practitioners for the treatment of diarrhea, colitis and gastroenteritis were inappropriate and random. In most cases the chosen antibiotic, can itself be associated with initiation or worsening of CDI. Conclusion: The needs for antimicrobial stewardship program to preserve the effectiveness of current available therapies are strongly recommended. This program must focus on the overall reduction of inappropriate antibiotic prescribing and ultimately on enforcing the adherence to the reputable antibacterial guidelines.

  15. Clostridium Difficile Infection Complicated By Toxic Megacolon In Immunocompetent Patient

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    Draganescu Miruna

    2017-02-01

    Full Text Available Toxic megacolon can be a form of severe clinical course of the infection with Clostridium difficile (ICD, life-threatening, requiring a particular course of treatment. Infection with Clostridium difficile in the Galati Infectious Disease Hospital presents rising number of cases, namely 172 cases in 2014, 271 cases in 2015 and 301 cases in 2016 with clinical evolutions with different severity degrees, including toxic megacolon and death. Among 744 patients with ICD in our clinic, since 1st January 2014 to 31 December 2016. The frequency of toxic megacolon (TM was 0,537%, so: 3 toxic megacolon cases with favorable evolution with treatment with vancomycin and metronidazole and just one case whose evolution was aggravated under this therapy and evolved favorably under treatment with tigecycline. The work presents this last case of ICD occurred in a 69 years old, immunocompetent man with unknown concomitant chronic diseases which undergoes surgery for bilateral inguinal hernia and receives antibiotherapy with cephalosporin IIIrd generation during surgery and after 7 days develops medium degree ICD with score Atlas 3 and receives therapy with oral vancomycin. He presents clinical aggravation during this therapy with the occurrence of colon dilatation, ascites and right pleurisy at ultrasound and therapy associated with metronidazole is decided. Clinical aggravation continues in this combined therapy with defining the clinical, colonoscopy and tomography criteria for TM and is decided surgical monitoring and replacing antibiotherapy with tigecycline. Evolution is favorable with tigecycline without surgical intervention.

  16. Management of inflammatory bowel disease with Clostridium difficile infection.

    Science.gov (United States)

    D'Aoust, Julie; Battat, Robert; Bessissow, Talat

    2017-07-21

    To address the management of Clostridium difficile ( C. difficile ) infection (CDI) in the setting of suspected inflammatory bowel disease (IBD)-flare. A systematic search of the Ovid MEDLINE and EMBASE databases by independent reviewers identified 70 articles including a total of 932141 IBD patients or IBD-related hospitalizations. In those with IBD, CDI is associated with increased morbidity, including subsequent escalation in IBD medical therapy, urgent colectomy and increased hospitalization, as well as excess mortality. Vancomycin-containing regimens are effective first-line therapies for CDI in IBD inpatients. No prospective data exists with regards to the safety or efficacy of initiating or maintaining corticosteroid, immunomodulator, or biologic therapy to treat IBD in the setting of CDI. Corticosteroid use is a risk factor for the development of CDI, while immunomodulators and biologics are not. Strong recommendations regarding when to initiate IBD specific therapy in those with CDI are precluded by a lack of evidence. However, based on expert opinion and observational data, initiation or resumption of immunosuppressive therapy after 48-72 h of targeted antibiotic treatment for CDI may be considered.

  17. Recurrence rate of clostridium difficile infection in hospitalized pediatric patients with inflammatory bowel disease.

    Science.gov (United States)

    Kelsen, Judith R; Kim, Jason; Latta, Dan; Smathers, Sarah; McGowan, Karin L; Zaoutis, Theodore; Mamula, Petar; Baldassano, Robert N

    2011-01-01

    The incidence and associated morbidity of Clostridium difficile (CD) infection has been increasing at an alarming rate in North America. Clostridium difficile-associated diarrhea (CDAD) is the leading cause of nosocomial diarrhea in the USA. Patients with CDAD have longer average hospital admissions and additional hospital costs. Evidence has demonstrated that patients with inflammatory bowel disease (IBD) have a higher incidence of CD in comparison to the general population. The aim of this study was to compare the rate of recurrence of CD in hospitalized pediatric patients with IBD compared to hospitalized controls. The secondary aim was to evaluate whether infection with CD resulted in a more severe disease course of IBD. This was a nested case control retrospective study of hospitalized pediatric patients. Diagnosis of CD was confirmed with stool Toxin A and B analysis. The following data were obtained from the medical records: demographic information, classification of IBD including location of disease, IBD therapy, and prior surgeries. In addition, prior hospital admissions within 1 year and antibiotic exposure were recorded. The same information was recorded following CD infection. Cases were patients with IBD and CD; two control populations were also studied: patients with CD but without IBD, and patients with IBD but without CD. For aim 1, a total of 111 eligible patients with IBD and CD infection and 77 eligible control patients with CD infection were included. The rate of recurrence of CD in the IBD population was 34% compared to 7.5% in the control population (P < 0.0001). In evaluating the effect of CD infection on IBD disease severity, we compared the 111 IBD patients with CD to a second control population of 127 IBD patients without CD. 57% of IBD-CD patients were readmitted with an exacerbation of disease within 6 months of infection with CD and 67% required escalation of therapy following CD infection, compared to 30% of IBD patients without CD (P

  18. Prevalence of Clostridium difficile infection in acute care hospitals, long-term care facilities, and outpatient clinics: Is Clostridium difficile infection underdiagnosed in long-term care facility patients?

    Science.gov (United States)

    Krishna, Amar; Pervaiz, Amina; Lephart, Paul; Tarabishy, Noor; Varakantam, Swapna; Kotecha, Aditya; Awali, Reda A; Kaye, Keith S; Chopra, Teena

    2017-10-01

    Clostridium difficile infection is a common cause of diarrhea in long-term care facility (LTCF) patients. The high prevalence of C difficile infection in LTCFs noted in our study calls for a critical need to educate LTCF staff to send diarrheal stool for C difficile testing to identify more cases and prevent transmission. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Total synthesis of five lipoteichoic acids of Clostridium difficile

    DEFF Research Database (Denmark)

    Hogendorf, Wouter Frederik Johan; Gisch, Nicolas; Schwudke, Dominik

    2014-01-01

    The emergence of hypervirulent resistant strains have made Clostridium difficile a notorious nosocomial pathogen and has resulted in a renewed interest in preventive strategies, such as vaccines based on (synthetic) cell wall antigens. Recently, the structure of the lipoteichoic acid (LTA......) of this species has been elucidated. Additionally, this LTA was found to induce the formation of protective antibodies against C. difficile in rabbits and mice. The LTA from C. difficile is isolated as a microheterogenous mixture, differing in size and composition, impeding any structure-activity relationship...... studies. To ensure reliable biological results, pure and well-defined synthetic samples are required. In this work the total synthesis of LTAs from C. difficile with defined chain length is described and the initial biological results are presented....

  20. Prevention of Clostridium difficile infection in hamsters using a non-toxigenic strain

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    Carlos Augusto de Oliveira Júnior

    2016-05-01

    Full Text Available ABSTRACT: The present study aimed to evaluate five non-toxigenic strains of Clostridium difficile (NTCD in vitro and to select one strain to prevent C. difficile (CDI infection in hamsters ( Mesocricetus auratus . The NTCD strains were evaluated for spore production in vitro, antimicrobial susceptibility and presence of antimicrobial resistance genes. Approximately 107 spores of the selected strain (Z31 were administered by esophageal gavage in hamsters pretreated with 30mg kg-1 of clindamycin. The challenge with a toxigenic strain of C. difficile was conducted at 36 and 72h, and the animals were observed for 28 days. The NTCD strain of C. difficile (Z31 was able to prevent CDI in all animals that received it.

  1. Increase in Clostridium difficile-related Mortality Rates, United States, 1999-2004

    Centers for Disease Control (CDC) Podcasts

    Deaths related to Clostridium difficile are on the rise in the United States. Matthew Redelings from the Los Angeles County Department of Health discusses the increase and what can be done to prevent this infection.

  2. Impact of end stage kidney disease on costs and outcomes of Clostridium difficile infection

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    Abhinav Goyal

    2017-09-01

    Conclusions: The presence of end stage kidney disease in hospitalized patients with Clostridium difficile infection is associated with higher mortality, a longer length of stay, and a higher cost of hospitalization.

  3. Reset of a critically disturbed microbial ecosystem: faecal transplant in recurrent Clostridium difficile infection

    NARCIS (Netherlands)

    Fuentes, Susana; van Nood, Els; Tims, Sebastian; Heikamp-de Jong, Ineke; ter Braak, Cajo J. F.; Keller, Josbert J.; Zoetendal, Erwin G.; de Vos, Willem M.

    2014-01-01

    Recurrent Clostridium difficile infection (CDI) can be effectively treated by infusion of a healthy donor faeces suspension. However, it is unclear what factors determine treatment efficacy. By using a phylogenetic microarray platform, we assessed composition, diversity and dynamics of faecal

  4. Bacillus Coagulans GBI-30 (BC30 improves indices of Clostridium difficile-Induced colitis in mice

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    Fitzpatrick Leo R

    2011-10-01

    Full Text Available Abstract Background Probiotics have beneficial effects in rodent models of Clostridium difficile (C. diffiicle-induced colitis. The spore forming probiotic strain Bacillus Coagulans GBI-30, 6086 (BC30 has demonstrated anti-inflammatory and immune-modulating effects in vitro. Our goal was to determine if BC30 improved C. difficile-induced colitis in mice. Starting on study day 0, female C57BL/6 mice were dosed by oro-gastric gavage for 15 days with vehicle (saline or BC30 (2 × 109 CFU per day. Mice in the C. difficile groups received an antibiotic mixture (study days 5 to 8 in the drinking water, and clindamycin (10 mg/kg, i.p., on study day 10. The C. difficile strain VPI 10463 was given by gavage at 104 CFU to induce colitis on day 11. On day 16, stools and colons were collected for further analyses. Results All mice treated with BC30 survived on study day 13, while two mice treated with vehicle did not survive. On day 12, a significant difference (p = 0.0002 in the percentage of mice with normal stools (66.7% was found in the BC30/C. difficile group, as compared to the vehicle/C. diffcile group (13.0%. On study day 16, 23.8% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0187. On this day, the stool consistency score for the BC30/C. difficile group (1.1 ± 0.2 was significantly lower (p C. difficile cohort (1.9 ± 0.2. BC30 modestly attenuated the colonic pathology (crypt damage, edema, leukocyte influx that was present following C. difficile infection. Colonic MIP-2 chemokine contents (pg/2 cm colon were: 10.2 ± 0.5 (vehicle/no C. difficile, 24.6 ± 9.5 (vehicle/C. difficile and 16.3 ± 4.3 (BC30/C. difficle. Conclusion The probiotic BC30 improved some parameters of C. difficile-induced colitis in mice. BC30 prolonged the survival of C. diffiicle infected mice. Particularly, this probiotic improved the stool consistency of mice, in this infectious colitis model.

  5. Bacillus Coagulans GBI-30 (BC30) improves indices of Clostridium difficile-Induced colitis in mice

    Science.gov (United States)

    2011-01-01

    Background Probiotics have beneficial effects in rodent models of Clostridium difficile (C. diffiicle)-induced colitis. The spore forming probiotic strain Bacillus Coagulans GBI-30, 6086 (BC30) has demonstrated anti-inflammatory and immune-modulating effects in vitro. Our goal was to determine if BC30 improved C. difficile-induced colitis in mice. Starting on study day 0, female C57BL/6 mice were dosed by oro-gastric gavage for 15 days with vehicle (saline) or BC30 (2 × 109 CFU per day). Mice in the C. difficile groups received an antibiotic mixture (study days 5 to 8 in the drinking water), and clindamycin (10 mg/kg, i.p., on study day 10). The C. difficile strain VPI 10463 was given by gavage at 104 CFU to induce colitis on day 11. On day 16, stools and colons were collected for further analyses. Results All mice treated with BC30 survived on study day 13, while two mice treated with vehicle did not survive. On day 12, a significant difference (p = 0.0002) in the percentage of mice with normal stools (66.7%) was found in the BC30/C. difficile group, as compared to the vehicle/C. diffcile group (13.0%). On study day 16, 23.8% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0187). On this day, the stool consistency score for the BC30/C. difficile group (1.1 ± 0.2) was significantly lower (p < 0.05) than for the vehicle/C. difficile cohort (1.9 ± 0.2). BC30 modestly attenuated the colonic pathology (crypt damage, edema, leukocyte influx) that was present following C. difficile infection. Colonic MIP-2 chemokine contents (pg/2 cm colon) were: 10.2 ± 0.5 (vehicle/no C. difficile), 24.6 ± 9.5 (vehicle/C. difficile) and 16.3 ± 4.3 (BC30/C. difficle). Conclusion The probiotic BC30 improved some parameters of C. difficile-induced colitis in mice. BC30 prolonged the survival of C. diffiicle infected mice. Particularly, this probiotic improved the stool consistency of mice, in this infectious colitis model. PMID

  6. Genomic and expression analysis of the vanG-like gene cluster of Clostridium difficile.

    Science.gov (United States)

    Peltier, Johann; Courtin, Pascal; El Meouche, Imane; Catel-Ferreira, Manuella; Chapot-Chartier, Marie-Pierre; Lemée, Ludovic; Pons, Jean-Louis

    2013-07-01

    Primary antibiotic treatment of Clostridium difficile intestinal diseases requires metronidazole or vancomycin therapy. A cluster of genes homologous to enterococcal glycopeptides resistance vanG genes was found in the genome of C. difficile 630, although this strain remains sensitive to vancomycin. This vanG-like gene cluster was found to consist of five ORFs: the regulatory region consisting of vanR and vanS and the effector region consisting of vanG, vanXY and vanT. We found that 57 out of 83 C. difficile strains, representative of the main lineages of the species, harbour this vanG-like cluster. The cluster is expressed as an operon and, when present, is found at the same genomic location in all strains. The vanG, vanXY and vanT homologues in C. difficile 630 are co-transcribed and expressed to a low level throughout the growth phases in the absence of vancomycin. Conversely, the expression of these genes is strongly induced in the presence of subinhibitory concentrations of vancomycin, indicating that the vanG-like operon is functional at the transcriptional level in C. difficile. Hydrophilic interaction liquid chromatography (HILIC-HPLC) and MS analysis of cytoplasmic peptidoglycan precursors of C. difficile 630 grown without vancomycin revealed the exclusive presence of a UDP-MurNAc-pentapeptide with an alanine at the C terminus. UDP-MurNAc-pentapeptide [d-Ala] was also the only peptidoglycan precursor detected in C. difficile grown in the presence of vancomycin, corroborating the lack of vancomycin resistance. Peptidoglycan structures of a vanG-like mutant strain and of a strain lacking the vanG-like cluster did not differ from the C. difficile 630 strain, indicating that the vanG-like cluster also has no impact on cell-wall composition.

  7. Environmental Contamination in Households of Patients with Recurrent Clostridium difficile Infection.

    Science.gov (United States)

    Shaughnessy, Megan K; Bobr, Aleh; Kuskowski, Michael A; Johnston, Brian D; Sadowsky, Michael J; Khoruts, Alexander; Johnson, James R

    2016-05-01

    Recurrent Clostridium difficile infection (R-CDI) is common and difficult to treat, potentially necessitating fecal microbiota transplantation (FMT). Although C. difficilespores persist in the hospital environment and cause infection, little is known about their potential presence or importance in the household environment. Households of R-CDI subjects in the peri-FMT period and of geographically matched and age-matched controls were analyzed for the presence ofC. difficile Household environmental surfaces and fecal samples from humans and pets in the household were examined. Households of post-FMT subjects were also examined (environmental surfaces only). Participants were surveyed regarding their personal history and household cleaning habits. Species identity and molecular characteristics of presumptive C. difficile isolates from environmental and fecal samples were determined by using the Pro kit (Remel, USA), Gram staining, PCR, toxinotyping, tcdC gene sequencing, and pulsed-field gel electrophoresis (PFGE). Environmental cultures detected C. difficile on ≥1 surface in 8/8 (100%) peri-FMT households, versus 3/8 (38%) post-FMT households and 3/8 (38%) control households (P= 0.025). The most common C. difficile-positive sites were the vacuum (11/27; 41%), toilet (8/30; 27%), and bathroom sink (5/29; 17%).C. difficile was detected in 3/36 (8%) fecal samples (two R-CDI subjects and one household member). Nine (90%) of 10 households with multiple C. difficile-positive samples had a single genotype present each. In conclusion,C. difficile was found in the household environment of R-CDI patients, but whether it was found as a cause or consequence of R-CDI is unknown. If household contamination leads to R-CDI, effective decontamination may be protective. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Recent advances in the understanding of antibiotic resistance in Clostridium difficile infection

    Science.gov (United States)

    2016-01-01

    Clostridium difficile epidemiology has changed in recent years, with the emergence of highly virulent types associated with severe infections, high rates of recurrences and mortality. Antibiotic resistance plays an important role in driving these epidemiological changes and the emergence of new types. While clindamycin resistance was driving historical endemic types, new types are associated with resistance to fluoroquinolones. Furthermore, resistance to multiple antibiotics is a common feature of the newly emergent strains and, in general, of many epidemic isolates. A reduced susceptibility to antibiotics used for C. difficile infection (CDI) treatment, in particular to metronidazole, has recently been described in several studies. Furthermore, an increased number of strains show resistance to rifamycins, used for the treatment of relapsing CDI. Several mechanisms of resistance have been identified in C. difficile, including acquisition of genetic elements and alterations of the antibiotic target sites. The C. difficile genome contains a plethora of mobile genetic elements, many of them involved in antibiotic resistance. Transfer of genetic elements among C. difficile strains or between C. difficile and other bacterial species can occur through different mechanisms that facilitate their spread. Investigations of the fitness cost in C. difficile indicate that both genetic elements and mutations in the molecular targets of antibiotics can be maintained regardless of the burden imposed on fitness, suggesting that resistances may persist in the C. difficile population also in absence of antibiotic selective pressure. The rapid evolution of antibiotic resistance and its composite nature complicate strategies in the treatment and prevention of CDI. The rapid identification of new phenotypic and genotypic traits, the implementation of effective antimicrobial stewardship and infection control programs, and the development of alternative therapies are needed to prevent and

  9. Vitamin D deficiency: A potential risk factor for Clostridium difficile infection

    OpenAIRE

    Youssef, Dima; Grant, William B; Peiris, Alan N

    2012-01-01

    Dima Youssef,1 William B Grant,2 Alan N Peiris3,41Department of Internal Medicine, Division of Infectious Diseases, 2Sunlight, Nutrition and Health Research Center, San Francisco, CA USA; 3Department of Medicine, Mountain Home VAMC, 4Department of Medicine, East Tennessee State University, Johnson City, Tennessee, USAIn the July 3, 2012 issue of the journal of Risk Management and Healthcare Policy, Martinez et al present a nice review on Clostridium difficile (C. difficile) infections.1 The d...

  10. Detecção dos genes codificantes da toxina CDT, e pesquisa de fatores que influenciam na produção de hemolisinas em amostras de Campylobacter jejuni de origem avícola

    Directory of Open Access Journals (Sweden)

    Michele M. Trindade

    2015-08-01

    Full Text Available Resumo: Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes micro-organismos em diferentes habitats tais como água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de Campylobacter jejuni de origem avícola para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB. Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA contendo 5% de sangue de ovino. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2, MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de C. jejuni em placas de TSA - sangue ovino foi possível observar que houve hemólise em 40% das amostras analisadas apenas com caldo TSB. Somente o ácido acético apresentou ação quelante sobre a atividade de hemolisinas em amostras de C. jejuni semeadas em placas de TSA - sangue ovino. Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação em Cadeia da Polimerase (PCR foram utilizadas 119 amostras de C. jejuni de origem avícola. Foi possível observar que 37,8% possuíam o perfil de genes cdtABC. Os resultados demonstraram em amostras avícolas a presença de cepas de C. jejuni com potencial virulento, devido à presença dos genes da toxina CDT e potencial hemolítico, que apresentou ação reduzida in vitro com ácido acético.

  11. Inducible Expression of spo0A as a Universal Tool for Studying Sporulation in Clostridium difficile.

    Science.gov (United States)

    Dembek, Marcin; Willing, Stephanie E; Hong, Huynh A; Hosseini, Siamand; Salgado, Paula S; Cutting, Simon M

    2017-01-01

    Clostridium difficile remains a leading nosocomial pathogen, putting considerable strain on the healthcare system. The ability to form endospores, highly resistant to environmental insults, is key to its persistence and transmission. However, important differences exist between the sporulation pathways of C. difficile and the model Gram-positive organism Bacillus subtilis . Amongst the challenges in studying sporulation in C. difficile is the relatively poor levels of sporulation and high heterogeneity in the sporulation process. To overcome these limitations we placed P tet regulatory elements upstream of the master regulator of sporulation, spo0A , generating a new strain that can be artificially induced to sporulate by addition of anhydrotetracycline (ATc). We demonstrate that this strain is asporogenous in the absence of ATc, and that ATc can be used to drive faster and more efficient sporulation. Induction of Spo0A is titratable and this can be used in the study of the spo0A regulon both in vitro and in vivo , as demonstrated using a mouse model of C. difficile infection (CDI). Insights into differences between the sporulation pathways in B. subtilis and C. difficile gained by study of the inducible strain are discussed, further highlighting the universal interest of this tool. The P tet -spo0A strain provides a useful background in which to generate mutations in genes involved in sporulation, therefore providing an exciting new tool to unravel key aspects of sporulation in C. difficile.

  12. The potential economic value of screening hospital admissions for Clostridium difficile.

    Science.gov (United States)

    Bartsch, S M; Curry, S R; Harrison, L H; Lee, B Y

    2012-11-01

    Asymptomatic Clostridium difficile carriage has a prevalence reported as high as 51-85 %; with up to 84 % of incident hospital-acquired infections linked to carriers. Accurately identifying carriers may limit the spread of Clostridium difficile. Since new technology adoption depends heavily on its economic value, we developed an analytic simulation model to determine the cost-effectiveness screening hospital admissions for Clostridium difficile from the hospital and third party payer perspectives. Isolation precautions were applied to patients testing positive, preventing transmission. Sensitivity analyses varied Clostridium difficile colonization rate, infection probability among secondary cases, contact isolation compliance, and screening cost. Screening was cost-effective (i.e., incremental cost-effectiveness ratio [ICER] ≤ $50,000/QALY) for every scenario tested; all ICER values were ≤ $256/QALY. Screening was economically dominant (i.e., saved costs and provided health benefits) with a ≥10.3 % colonization rate and ≥5.88 % infection probability when contact isolation compliance was ≥25 % (hospital perspective). Under some conditions screening led to cost savings per case averted (range, $53-272). Clostridium difficile screening, coupled with isolation precautions, may be a cost-effective intervention to hospitals and third party payers, based on prevalence. Limiting Clostridium difficile transmission can reduce the number of infections, thereby reducing its economic burden to the healthcare system.

  13. The Incidence of Nosocomial Toxigenic Clostridium difficile Associated Diarrhea in Tehran Tertiary Medical Centers

    Directory of Open Access Journals (Sweden)

    Norakhoda Sadeghifard

    2010-10-01

    Full Text Available Clostridium difficile is the most common cause of nosocomial diarrhea. It is usually a consequence of antibiotic treatment, But sporadic cases can occur. This study was aimed to determine the frequency of the nosocomial Clostridium difficile (C. difficile associated diarrhea in Tehran University of Medical Sciences hospitals and study of antibacterial susceptibility of isolates. In this study a total of 942 stool samples from patients with nosocomial diarrhea that were hospitalized in Imam Khomeini hospital, Shariati hospital and Children clinical center were collected. The samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA and incubated in anaerobic conditions, at 37°C for 5 days. Isolates were characterized to species level by conventional biochemical tests. Bacterial cytotoxicity was assayed on tissue culture (vero. Antimicrobial sensitivity of isolated toxigenic C. difficile were investigated by kirby Beuer method (disk diffusion. Our findings show that, of the total patients, 57 toxigenic C. difficile (6.1% were isolated. Results of statistical analysis show significant differences between the rate of isolated toxigenic C. difficile and age group of patients (P

  14. Characterization of a stable, metronidazole-resistant Clostridium difficile clinical isolate.

    Directory of Open Access Journals (Sweden)

    Tarah Lynch

    Full Text Available BACKGROUND: Clostridium difficile are gram-positive, spore forming anaerobic bacteria that are the leading cause of healthcare-associated diarrhea, usually associated with antibiotic usage. Metronidazole is currently the first-line treatment for mild to moderate C. difficile diarrhea however recurrence occurs at rates of 15-35%. There are few reports of C. difficile metronidazole resistance in the literature, and when observed, the phenotype has been transient and lost after storage or exposure of the bacteria to freeze/thaw cycles. Owing to the unstable nature of the resistance phenotype in the laboratory, clinical significance and understanding of the resistance mechanisms is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Genotypic and phenotypic characterization was performed on a metronidazole resistant clinical isolate of C. difficile. Whole-genome sequencing was used to identify potential genetic contributions to the phenotypic variation observed with molecular and bacteriological techniques. Phenotypic observations of the metronidazole resistant strain revealed aberrant growth in broth and elongated cell morphology relative to a metronidazole-susceptible, wild type NAP1 strain. Comparative genomic analysis revealed single nucleotide polymorphism (SNP level variation within genes affecting core metabolic pathways such as electron transport, iron utilization and energy production. CONCLUSIONS/SIGNIFICANCE: This is the first characterization of stable, metronidazole resistance in a C. difficile isolate. The study provides an in-depth genomic and phenotypic analysis of this strain and provides a foundation for future studies to elucidate mechanisms conferring metronidazole resistance in C. difficile that have not been previously described.

  15. Saccharomyces boulardii for the prevention of hospital onset Clostridium difficile infection.

    Science.gov (United States)

    Flatley, Elizabeth A; Wilde, Ashley M; Nailor, Michael D

    2015-03-01

    Probiotics, including Saccharomyces boulardii, have been advocated for the prevention of Clostridium difficile infection. The aim of this project was to evaluate the effects of the removal of S. boulardii from an automatic antibiotic order set and hospital formulary on hospital onset C. difficile infection rates. A retrospective chart review was performed on all patients with hospital onset C. difficile infection during the 13 months prior (control group) and the 13 months after (study group) removal of an automatic order set linking S. boulardii capsules to certain broad spectrum antibiotics. A large 800+ bed tertiary hospital. Among all hospitalized patients, the rate of hospital onset C. difficile infection was 0.99 per 1000 patient days while the S. boulardii protocol was active compared with 1.04 per 1000 patient days (p=0.10) after S. boulardii was removed from the formulary. No difference in the rate of hospital onset C. difficile infection was detected in patients receiving the linked broad spectrum antibiotics during and after the removal of the protocol (1.25% vs. 1.51%, respectively; p=0.70). Removal of S. boulardii administration to patients receiving broad spectrum antibiotics and the hospital formulary did not impact the rate of hospital onset C. difficile infection in either the hospital population or patients receiving broad spectrum antibiotics.

  16. Inducible Expression of spo0A as a Universal Tool for Studying Sporulation in Clostridium difficile

    Directory of Open Access Journals (Sweden)

    Marcin Dembek

    2017-09-01

    Full Text Available Clostridium difficile remains a leading nosocomial pathogen, putting considerable strain on the healthcare system. The ability to form endospores, highly resistant to environmental insults, is key to its persistence and transmission. However, important differences exist between the sporulation pathways of C.