WorldWideScience

Sample records for perfringens enterotoxin cpe

  1. Claudins Overexpression in Ovarian Cancer: Potential Targets for Clostridium Perfringens Enterotoxin (CPE Based Diagnosis and Therapy

    Directory of Open Access Journals (Sweden)

    Diana P. English

    2013-05-01

    Full Text Available Claudins are a family of tight junction proteins regulating paracellular permeability and cell polarity with different patterns of expression in benign and malignant human tissues. There are approximately 27 members of the claudin family identified to date with varying cell and tissue-specific expression. Claudins-3, -4 and -7 represent the most highly differentially expressed claudins in ovarian cancer. While their exact role in ovarian tumors is still being elucidated, these proteins are thought to be critical for ovarian cancer cell invasion/dissemination and resistance to chemotherapy. Claudin-3 and claudin-4 are the natural receptors for the Clostridium perfringens enterotoxin (CPE, a potent cytolytic toxin. These surface proteins may therefore represent attractive targets for the detection and treatment of chemotherapy-resistant ovarian cancer and other aggressive solid tumors overexpressing claudin-3 and -4 using CPE-based theranostic agents.

  2. Organization of the cpe locus in CPE-positive clostridium perfringens type C and D isolates.

    Directory of Open Access Journals (Sweden)

    Jihong Li

    2010-06-01

    Full Text Available Clostridium perfringens enterotoxin (encoded by the cpe gene contributes to several important human, and possibly veterinary, enteric diseases. The current study investigated whether cpe locus organization in type C or D isolates resembles one of the three (one chromosomal and two plasmid-borne cpe loci commonly found amongst type A isolates. Multiplex PCR assays capable of detecting sequences in those type A cpe loci failed to amplify products from cpe-positive type C and D isolates, indicating these isolates possess different cpe locus arrangements. Therefore, restriction fragments containing the cpe gene were cloned and sequenced from two type C isolates and one type D isolate. The obtained cpe locus sequences were then used to construct an overlapping PCR assay to assess cpe locus diversity amongst other cpe-positive type C and D isolates. All seven surveyed cpe-positive type C isolates had a plasmid-borne cpe locus partially resembling the cpe locus of type A isolates carrying a chromosomal cpe gene. In contrast, all eight type D isolates shared the same plasmid-borne cpe locus, which differed substantially from the cpe locus present in other C. perfringens by containing two copies of an ORF with 67% identity to a transposase gene (COG4644 found in Tn1546, but not previously associated with the cpe gene. These results identify greater diversity amongst cpe locus organization than previously appreciated, providing new insights into cpe locus evolution. Finally, evidence for cpe gene mobilization was found for both type C and D isolates, which could explain their cpe plasmid diversity.

  3. Bystander Host Cell Killing Effects of Clostridium perfringens Enterotoxin

    Directory of Open Access Journals (Sweden)

    Archana Shrestha

    2016-12-01

    Full Text Available Clostridium perfringens enterotoxin (CPE binds to claudin receptors, e.g., claudin-4, and then forms a pore that triggers cell death. Pure cultures of host cells that do not express claudin receptors, e.g., fibroblasts, are unaffected by pathophysiologically relevant CPE concentrations in vitro. However, both CPE-insensitive and CPE-sensitive host cells are present in vivo. Therefore, this study tested whether CPE treatment might affect fibroblasts when cocultured with CPE-sensitive claudin-4 fibroblast transfectants or Caco-2 cells. Under these conditions, immunofluorescence microscopy detected increased death of fibroblasts. This cytotoxic effect involved release of a toxic factor from the dying CPE-sensitive cells, since it could be reproduced using culture supernatants from CPE-treated sensitive cells. Supernatants from CPE-treated sensitive cells, particularly Caco-2 cells, were found to contain high levels of membrane vesicles, often containing a CPE species. However, most cytotoxic activity remained in those supernatants even after membrane vesicle depletion, and CPE was not detected in fibroblasts treated with supernatants from CPE-treated sensitive cells. Instead, characterization studies suggest that a major cytotoxic factor present in supernatants from CPE-treated sensitive cells may be a 10- to 30-kDa host serine protease or require the action of that host serine protease. Induction of caspase-3-mediated apoptosis was found to be important for triggering release of the cytotoxic factor(s from CPE-treated sensitive host cells. Furthermore, the cytotoxic factor(s in these supernatants was shown to induce a caspase-3-mediated killing of fibroblasts. This bystander killing effect due to release of cytotoxic factors from CPE-treated sensitive cells could contribute to CPE-mediated disease.

  4. Cloning the enterotoxin gene from Clostridium perfringens type A

    OpenAIRE

    Iwanejko, Lesley Ann.

    1991-01-01

    A C. perfringens type A genomic library was constructed in E. coli by banking overlapping 6-10 kbp Hind III fragments of chromosomal DNA from the enterotoxin (CPE) positive strain NCTC 8239 into the pUC derived vector pHG165. The library was screened by colony hybridization with a degenerate 26 bp oligonucleotide probe, derived from the amino acid sequence CPE9_17A. complex mixture of plasmid DNA was isolated from the only hybridization positive clone. A second round of screening picked out a...

  5. Effects of Bile Acids and Nisin on the Production of Enterotoxin by Clostridium perfringens in a Nutrient-Rich Medium

    Directory of Open Access Journals (Sweden)

    Miseon Park

    2018-01-01

    Full Text Available Clostridium perfringens is the second most common cause of bacterial foodborne illness in the United States, with nearly a million cases each year. C. perfringens enterotoxin (CPE, produced during sporulation, damages intestinal epithelial cells by pore formation, which results in watery diarrhea. The effects of low concentrations of nisin and bile acids on sporulation and toxin production were investigated in C. perfringens SM101, which carries an enterotoxin gene on the chromosome, in a nutrient-rich medium. Bile acids and nisin increased production of enterotoxin in cultures; bile acids had the highest effect. Both compounds stimulated the transcription of enterotoxin and sporulation-related genes and production of spores during the early growth phase. They also delayed spore outgrowth and nisin was more inhibitory. Bile acids and nisin enhanced enterotoxin production in some but not all other C. perfringens isolates tested. Low concentrations of bile acids and nisin may act as a stress signal for the initiation of sporulation and the early transcription of sporulation-related genes in some strains of C. perfringens, which may result in increased strain-specific production of enterotoxin in those strains. This is the first report showing that nisin and bile acids stimulated the transcription of enterotoxin and sporulation-related genes in a nutrient-rich bacterial culture medium.

  6. Effects of Bile Acids and Nisin on the Production of Enterotoxin by Clostridium perfringens in a Nutrient-Rich Medium.

    Science.gov (United States)

    Park, Miseon; Rafii, Fatemeh

    2018-01-01

    Clostridium perfringens is the second most common cause of bacterial foodborne illness in the United States, with nearly a million cases each year. C. perfringens enterotoxin (CPE), produced during sporulation, damages intestinal epithelial cells by pore formation, which results in watery diarrhea. The effects of low concentrations of nisin and bile acids on sporulation and toxin production were investigated in C. perfringens SM101, which carries an enterotoxin gene on the chromosome, in a nutrient-rich medium. Bile acids and nisin increased production of enterotoxin in cultures; bile acids had the highest effect. Both compounds stimulated the transcription of enterotoxin and sporulation-related genes and production of spores during the early growth phase. They also delayed spore outgrowth and nisin was more inhibitory. Bile acids and nisin enhanced enterotoxin production in some but not all other C. perfringens isolates tested. Low concentrations of bile acids and nisin may act as a stress signal for the initiation of sporulation and the early transcription of sporulation-related genes in some strains of C. perfringens , which may result in increased strain-specific production of enterotoxin in those strains. This is the first report showing that nisin and bile acids stimulated the transcription of enterotoxin and sporulation-related genes in a nutrient-rich bacterial culture medium.

  7. Identification of novel Clostridium perfringens type E strains that carry an iota toxin plasmid with a functional enterotoxin gene.

    Directory of Open Access Journals (Sweden)

    Kazuaki Miyamoto

    Full Text Available Clostridium perfringens enterotoxin (CPE is a major virulence factor for human gastrointestinal diseases, such as food poisoning and antibiotic associated diarrhea. The CPE-encoding gene (cpe can be chromosomal or plasmid-borne. Recent development of conventional PCR cpe-genotyping assays makes it possible to identify cpe location (chromosomal or plasmid in type A isolates. Initial studies for developing cpe genotyping assays indicated that all cpe-positive strains isolated from sickened patients were typable by cpe-genotypes, but surveys of C. perfringens environmental strains or strains from feces of healthy people suggested that this assay might not be useful for some cpe-carrying type A isolates. In the current study, a pulsed-field gel electrophoresis Southern blot assay showed that four cpe-genotype untypable isolates carried their cpe gene on a plasmid of ∼65 kb. Complete sequence analysis of the ∼65 kb variant cpe-carrying plasmid revealed no intact IS elements and a disrupted cytosine methyltransferase (dcm gene. More importantly, this plasmid contains a conjugative transfer region, a variant cpe gene and variant iota toxin genes. The toxin genes encoded by this plasmid are expressed based upon the results of RT-PCR assays. The ∼65 kb plasmid is closely related to the pCPF4969 cpe plasmid of type A isolates. MLST analyses indicated these isolates belong to a unique cluster of C. perfringens. Overall, these isolates carrying a variant functional cpe gene and iota toxin genes represent unique type E strains.

  8. A complex array of Hpr consensus DNA recognition sequences proximal to the enterotoxin gene in Clostridium perfringens type A.

    Science.gov (United States)

    Brynestad, S; Iwanejko, L A; Stewart, G S; Granum, P E

    1994-01-01

    Enterotoxin production in Clostridium perfringens is both strain dependent and sporulation associated. Underlying these phenotypic observations must lie a genetic and molecular explanation and the principal keys will be held within the DNA sequence both upstream and downstream of the structural gene cpe. In accordance with the above we have sequenced 4.1 kbp of DNA upstream of cpe in the type strain NCTC 8239. A region of DNA extending up to 1.5 kb 5' to cpe is conserved in all enterotoxin-positive strains. This region contains a putative ORF with substantial homology to an ORF in the Salmonella typhimurium IS200 insertion element and, in addition, contains multiple perfect consensus DNA-binding sequences for the Bacillus subtilis transition state regulator Hpr. The detailed structural elements revealed by the sequence analysis are presented and used to develop a new perspective on the molecular basis of enterotoxin production in this important food-poisoning bacterium.

  9. CodY Promotes Sporulation and Enterotoxin Production by Clostridium perfringens Type A Strain SM101.

    Science.gov (United States)

    Li, Jihong; Freedman, John C; Evans, Daniel R; McClane, Bruce A

    2017-03-01

    Clostridium perfringens type D strains cause enterotoxemia and enteritis in livestock via epsilon toxin production. In type D strain CN3718, CodY was previously shown to increase the level of epsilon toxin production and repress sporulation. C. perfringens type A strains producing C. perfringens enterotoxin (CPE) cause human food poisoning and antibiotic-associated diarrhea. Sporulation is critical for C. perfringens type A food poisoning since spores contribute to transmission and resistance in the harsh food environment and sporulation is essential for CPE production. Therefore, the current study asked whether CodY also regulates sporulation and CPE production in SM101, a derivative of C. perfringens type A food-poisoning strain NCTC8798. An isogenic codY -null mutant of SM101 showed decreased levels of spore formation, along with lower levels of CPE production. A complemented strain recovered wild-type levels of both sporulation and CPE production. When this result was coupled with the earlier results obtained with CN3718, it became apparent that CodY regulation of sporulation varies among different C. perfringens strains. Results from quantitative reverse transcriptase PCR analysis clearly demonstrated that, during sporulation, codY transcript levels remained high in SM101 but rapidly declined in CN3718. In addition, abrB gene expression patterns varied significantly between codY -null mutants of SM101 and CN3718. Compared to the levels in their wild-type parents, the level of abrB gene expression decreased in the CN3718 codY -null mutant strain but significantly increased in the SM101 codY -null mutant strain, demonstrating CodY-dependent regulation differences in abrB expression between these two strains. This difference appears to be important since overexpression of the abrB gene in SM101 reduced the levels of sporulation and enterotoxin production, supporting the involvement of AbrB repression in regulating C. perfringens sporulation. Copyright © 2017

  10. Comparison of toxicity neutralization-, ELISA- and PCR tests for typing of Clostridium perfringens and detection of the enterotoxin gene by PCR

    DEFF Research Database (Denmark)

    Møller, Kristian; Ahrens, Peter

    1996-01-01

    A polymerase chain reaction (PCR) was developed for the specific amplification of a part of each of the five Clostridium perfringens toxin genes: alpha (alpha), beta (beta), epsilon (epsilon), iota (iota), and enterotoxin (CPE). While the toxicity neutralization test (TNT) only showed limited...

  11. Nitrate salts suppress sporulation and production of enterotoxin in Clostridium perfringens strain NCTC8239.

    Science.gov (United States)

    Yasugi, Mayo; Otsuka, Keisuke; Miyake, Masami

    2016-10-01

    Clostridium perfringens type A is a common source of food-borne illness in humans. Ingested vegetative cells sporulate in the small intestinal tract and in the process produce C. perfringens enterotoxin (CPE). Although sporulation plays a critical role in the pathogenesis of food-borne illness, the molecules triggering/inhibiting sporulation are still largely unknown. It has previously been reported by our group that sporulation is induced in C. perfringens strain NCTC8239 co-cultured with Caco-2 cells in Dulbecco's Modified Eagle Medium (DMEM). In contrast, an equivalent amount of spores was not observed when bacteria were co-cultured in Roswell Park Memorial Institute-1640 medium (RPMI). In the present study it was found that, when these two media are mixed, RPMI inhibits sporulation and CPE production induced in DMEM. When a component of RPMI was added to DMEM, it was found that calcium nitrate (Ca[NO 3 ] 2 ) significantly inhibits sporulation and CPE production. The number of spores increased when Ca(NO 3 ) 2 -deficient RPMI was used. The other nitrate salts significantly suppressed sporulation, whereas the calcium salts used did not. qPCR revealed that nitrate salts increased expression of bacterial nitrate/nitrite reductase. Furthermore, it was found that nitrite and nitric oxide suppress sporulation. In the sporulation stages, Ca(NO 3 ) 2 down-regulated the genes controlled by Spo0A, a master regulator of sporulation, but not spo0A itself. Collectively, these results indicate that nitrate salts suppress sporulation and CPE production by down-regulating Spo0A-regulated genes in C. perfringens strain NCTC8239. Nitrate reduction may be associated with inhibition of sporulation. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

  12. Determination of enterotoxigenic Clostridium perfringens by detecting of the cpa and cpe genes in stool samples of human origin, associated to gastrointestinal disease

    International Nuclear Information System (INIS)

    Oropeza Barrios, Gletty

    2014-01-01

    A molecular methodology is provided to the Centro Nacional de Referencia de Bacteriologia (CNRB) of the Instituto Costarricense de Investigacion y Ensenanza en Nutricion y Salud. An opportune diagnosis is realized of enterotoxigenic Clostridium perfringens in stool samples of sporadic cases and cases associated to foodborne disease outbreaks. DNA extraction of the white microorganism was performed through the methodology implemented in the CNRB. The technique of polymerase chain reaction (PCR) were adapted and standardized to establish the identification of C. perfringens to species level and detection of cpe gene coding for enterotoxin. The sensitivity of the method was determined in a selective culture medium for C. perfringens (Tryptose sulfite cycloserine Agar). A detection limit of about 2,3 x 10 4 CFU/ml was reached for the cpe gene and at least 2,8 x 10 2 CFU/ml for the cpa gene. Retrospective analysis of 61 samples of diarrheal stool suspicious by C. perfringens is performed to evaluate the efficacy of the technique. Three outbreaks caused by C. perfringens were identified and a 10% of positivity in the samples were obtained analyzed during the period between July 2012-March 2014 [es

  13. Stimulation of Clostridium perfringens enterotoxin formation by caffeine and theobromine.

    Science.gov (United States)

    Labbe, R G; Nolan, L L

    1981-01-01

    In the presence of 100 micrograms of caffeine per ml or 200 micrograms of theobromine per ml, sporulation of Clostridium perfringens NCTC 8679 rose from less than 1 to 80 or 85%. Enterotoxin concentration increased from undetectable levels to 450 micrograms/mg of cell extract protein. Heat-resistant spore levels increased from less than 1,000 to between 1 X 10(7) and 2 X 10(7)/ml. These effects were partially reversible by the addition of adenosine or thymidine. In the case of NCTC 8238, caffeine and theobromine caused a three- to fourfold increase in the percentages of cells possessing refractile spores and a similar increase in enterotoxin concentration. Heat-resistant spore levels, however, were unaffected. Inosine was ineffective in promoting sporulation in NCTC 8679. PMID:6271685

  14. Molecular analysis of the interaction between Clostridium perfringens Enterotoxin and Claudins

    OpenAIRE

    Protze, Jonas

    2015-01-01

    Claudins are essential constituents of Tight Junctions (TJs) and responsible for maintenance of these cell-cell contacts. Binding of Clostridium perfringens Enterotoxin’s C-terminal domain (cCPE) to the extracellular loop 2 (EZS2) of claudins, especially Cld3, Cld4 and Cld6-Cld9 causes a reversible opening of TJs. Thus, a structure-function analysis of this system is relevant for biomedical application, since cCPE could be used to enhance paracellular drug uptake. Furthermore cCPE respectivel...

  15. Cloning in Escherichia coli of the enterotoxin gene from Clostridium perfringens type A.

    Science.gov (United States)

    Iwanejko, L A; Routledge, M N; Stewart, G S

    1989-04-01

    A 26 bp DNA probe has been constructed with minimal degeneracy to the protein sequence for Clostridium perfringens enterotoxin. The probe has been hybridized against a 6-10 kb chromosomal bank from C. perfringens 8239, prepared as a HindIII partial digest in pHG165. From this survey a clone has been identified containing a 6.8 kb DNA insert with strong hybridization to the probe. Direct plasmid sequencing has identified a translational reading frame within this clone which correlates with the known protein sequence for the type A enterotoxin. DNA sequences 5' to this open reading frame and containing the putative transcriptional control regions show areas of significant homology with regions upstream from the ATG codon of the tetanus toxin gene.

  16. Claudin-4 Overexpression in Epithelial Ovarian Cancer Is Associated with Hypomethylation and Is a Potential Target for Modulation of Tight Junction Barrier Function Using a C-Terminal Fragment of Clostridium perfringens Enterotoxin

    Directory of Open Access Journals (Sweden)

    Babak Litkouhi

    2007-04-01

    Full Text Available BACKGROUND: Claudin-4, a tight junction (TJ protein and receptor for the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE, is overexpressed in epithelial ovarian cancer (EOC. Previous research suggests DNA methylation is a mechanism for claudin-4 overexpression in cancer and that C-CPE acts as an absorption-enhancing agent in claudin-4expressing cells. We sought to correlate claudin-4 overexpression in EOC with clinical outcomes and TJ barrier function, investigate DNA methylation as a mechanism for overexpression, and evaluate the effect of C-CPE on the TJ. METHODS: Claudin-4 expression in EOC was quantified and correlated with clinical outcomes. Claudin-4 methylation status was determined, and claudin-4-negative cell lines were treated with a demethylating agent. Electric cell-substrate impedance sensing was used to calculate junctional (paracellular resistance (Rb in EOC cells after claudin-4 silencing and after C-CPE treatment. RESULTS: Claudin4 overexpression in EOC does not correlate with survival or other clinical endpoints and is associated with hypomethylation. Claudin-4 overexpression correlates with Rb and C-CPE treatment of EOC cells significantly decreased Rb in a dose- and claudin-4-dependent noncytotoxic manner. CONCLUSIONS: C-CPE treatment of EOC cells leads to altered TJ function. Further research is needed to determine the potential clinical applications of C-CPE in EOC drug delivery strategies.

  17. Identification and Characterization of a New Enterotoxin Produced by Clostridium perfringens Isolated from Food Poisoning Outbreaks.

    Directory of Open Access Journals (Sweden)

    Daisuke Irikura

    Full Text Available There is a strain of Clostridium perfringens, W5052, which does not produce a known enterotoxin. We herein report that the strain W5052 expressed a homologue of the iota-like toxin components sa and sb of C. spiroforme, named Clostridium perfringens iota-like enterotoxin, CPILE-a and CPILE-b, respectively, based on the results of a genome sequencing analysis and a systematic protein screening. In the nicotinamide glyco-hydrolase (NADase assay the hydrolysis activity was dose-dependently increased by the concentration of rCPILE-a, as judged by the mass spectrometry analysis. In addition, the actin monomer of the lysates of Vero and L929 cells were radiolabeled in the presence of [32P]NAD and rCPILE-a. These findings indicated that CPILE-a possesses ADP-ribosylation activity. The culture supernatant of W5052 facilitated the rounding and killing of Vero and L929 cells, but the rCPILE-a or a non-proteolyzed rCPILE-b did not. However, a trypsin-treated rCPILE-b did. Moreover, a mixture of rCPILE-a and the trypsin-treated rCPILE-b enhanced the cell rounding and killing activities, compared with that induced by the trypsin-treated rCPILE-b alone. The injection of the mixture of rCPILE-a and the trypsin-treated rCPILE-b into an ileum loop of rabbits evoked the swelling of the loop and accumulation of the fluid dose-dependently, suggesting that CPILE possesses enterotoxic activity. The evidence presented in this communication will facilitate the epidemiological, etiological, and toxicological studies of C. perfringens food poisoning, and also stimulate studies on the transfer of the toxins' gene(s among the Genus Clostridium.

  18. Effect of low-dose gamma irradiation on enterotoxin-positive strains of Clostridium perfringens Type A

    International Nuclear Information System (INIS)

    Barnhart, H.M. Jr.

    1976-01-01

    The effect of low-dose gamma irradiation on selected enterotoxin producing strains of Clostridium perfringens Type A was studied. The radioresistance of three strains NCTC-8239, NCTC-10239 and NCTC-8798 in 0.1 percent peptone water, beef gravy and ground beef was determined for both vegetative cells and spores. D 10 values were approximately 30 Krad in 0.1 percent peptone water and 175 Krad in beef menstruums. D 10 values for spores were approximately 250 Krad in 0.1 percent peptone water and 335 Krad in beef. Low-level irradiation induced a 2 hr lag for cell recovery at 37 0 C following irradiation though this was strain dependent. Heat resistance of vegetative cells decreased following irradiation, although one strain was stimulated in growth response and unaltered in its heat resistance. Spore activation and germination were not affected by low-level irradiation. Spores were not significantly inactivated at this level. Irradiation had no effect on subsequent survival of vegetative cells stored at cold temperatures. Enterotoxin production by irradiated cultures was not affected by the irradiation treatment. A method for quantitating C. perfringens enterotoxin using crossed-immunoelectrophoresis was developed. It was found that this technique could detect at least .05 g of enterotoxin, could utilize crude enterotoxin preparations and was more sensitive than other methods based on biological activity

  19. Genetic characterization of type A enterotoxigenic Clostridium perfringens strains.

    Directory of Open Access Journals (Sweden)

    Agi Deguchi

    2009-05-01

    Full Text Available Clostridium perfringens type A, is both a ubiquitous environmental bacterium and a major cause of human gastrointestinal disease, which usually involves strains producing C. perfringens enterotoxin (CPE. The gene (cpe encoding this toxin can be carried on the chromosome or a large plasmid. Interestingly, strains carrying cpe on the chromosome and strains carrying cpe on a plasmid often exhibit different biological characteristics, such as resistance properties against heat. In this study, we investigated the genetic properties of C. perfringens by PCR-surveying 21 housekeeping genes and genes on representative plasmids and then confirmed those results by Southern blot assay (SB of five genes. Furthermore, sequencing analysis of eight housekeeping genes and multilocus sequence typing (MLST analysis were also performed. Fifty-eight C. perfringens strains were examined, including isolates from: food poisoning cases, human gastrointestinal disease cases, foods in Japan or the USA, or feces of healthy humans. In the PCR survey, eight of eleven housekeeping genes amplified positive reactions in all strains tested. However, by PCR survey and SB assay, one representative virulence gene, pfoA, was not detected in any strains carrying cpe on the chromosome. Genes involved in conjugative transfer of the cpe plasmid were also absent from almost all chromosomal cpe strains. MLST showed that, regardless of their geographic origin, date of isolation, or isolation source, chromosomal cpe isolates, i assemble into one definitive cluster ii lack pfoA and iii lack a plasmid related to the cpe plasmid. Similarly, independent of their origin, strains carrying a cpe plasmid also appear to be related, but are more variable than chromosomal cpe strains, possibly because of the instability of cpe-borne plasmid(s and/or the conjugative transfer of cpe-plasmid(s into unrelated C. perfringens strains.

  20. Detection of enterotoxigenic Clostridium perfringens in meat samples by using molecular methods.

    Science.gov (United States)

    Kaneko, Ikuko; Miyamoto, Kazuaki; Mimura, Kanako; Yumine, Natsuko; Utsunomiya, Hirotoshi; Akimoto, Shigeru; McClane, Bruce A

    2011-11-01

    To prevent food-borne bacterial diseases and to trace bacterial contamination events to foods, microbial source tracking (MST) methods provide important epidemiological information. To apply molecular methods to MST, it is necessary not only to amplify bacterial cells to detection limit levels but also to prepare DNA with reduced inhibitory compounds and contamination. Isolates carrying the Clostridium perfringens enterotoxin gene (cpe) on the chromosome or a plasmid rank among the most important food-borne pathogens. Previous surveys indicated that cpe-positive C. perfringens isolates are present in only ∼5% of nonoutbreak food samples and then only at low numbers, usually less than 3 cells/g. In this study, four molecular assays for the detection of cpe-positive C. perfringens isolates, i.e., ordinary PCR, nested PCR, real-time PCR, and loop-mediated isothermal amplification (LAMP), were developed and evaluated for their reliability using purified DNA. For use in the artificial contamination of meat samples, DNA templates were prepared by three different commercial DNA preparation kits. The four molecular assays always detected cpe when >10³ cells/g of cpe-positive C. perfringens were present, using any kit. Of three tested commercial DNA preparation kits, the InstaGene matrix kit appeared to be most suitable for the testing of a large number of samples. By using the InstaGene matrix kit, the four molecular assays efficiently detected cpe using DNA prepared from enrichment culture specimens of meat samples contaminated with low numbers of cpe-positive C. perfringens vegetative cells or spores. Overall, the current study developed molecular assay protocols for MST to detect the contamination of foods with low numbers of cells, and at a low frequency, of cpe-positive C. perfringens isolates.

  1. Detection of Enterotoxigenic Clostridium perfringens in Meat Samples by Using Molecular Methods▿

    Science.gov (United States)

    Kaneko, Ikuko; Miyamoto, Kazuaki; Mimura, Kanako; Yumine, Natsuko; Utsunomiya, Hirotoshi; Akimoto, Shigeru; McClane, Bruce A.

    2011-01-01

    To prevent food-borne bacterial diseases and to trace bacterial contamination events to foods, microbial source tracking (MST) methods provide important epidemiological information. To apply molecular methods to MST, it is necessary not only to amplify bacterial cells to detection limit levels but also to prepare DNA with reduced inhibitory compounds and contamination. Isolates carrying the Clostridium perfringens enterotoxin gene (cpe) on the chromosome or a plasmid rank among the most important food-borne pathogens. Previous surveys indicated that cpe-positive C. perfringens isolates are present in only ∼5% of nonoutbreak food samples and then only at low numbers, usually less than 3 cells/g. In this study, four molecular assays for the detection of cpe-positive C. perfringens isolates, i.e., ordinary PCR, nested PCR, real-time PCR, and loop-mediated isothermal amplification (LAMP), were developed and evaluated for their reliability using purified DNA. For use in the artificial contamination of meat samples, DNA templates were prepared by three different commercial DNA preparation kits. The four molecular assays always detected cpe when >103 cells/g of cpe-positive C. perfringens were present, using any kit. Of three tested commercial DNA preparation kits, the InstaGene matrix kit appeared to be most suitable for the testing of a large number of samples. By using the InstaGene matrix kit, the four molecular assays efficiently detected cpe using DNA prepared from enrichment culture specimens of meat samples contaminated with low numbers of cpe-positive C. perfringens vegetative cells or spores. Overall, the current study developed molecular assay protocols for MST to detect the contamination of foods with low numbers of cells, and at a low frequency, of cpe-positive C. perfringens isolates. PMID:21890671

  2. GENOTYPING OF CLOSTRIDIUM PERFRINGENS FROM FRESH WATER FISH AND FISH PICKLES

    Directory of Open Access Journals (Sweden)

    Adarsh Jain

    2012-08-01

    Full Text Available This study aims to evaluate the genotypes of Clostridium perfringens in fish and fish based products from Tamil Nadu and Kerala states of India. A total of 301 samples consisting intestinal contents of freshwater fish (234 from various dams, freshwater lakes, ponds, retail shops and markets and fish pickles (67 obtained from randomly selected retail shops and supermarkets were investigated. Bacterial isolations, identifications and phenotypic characterization of virulence factors were carried out as per standard microbiological procedures. Genotyping of the C. perfringens isolates were done by amplifying four major lethal toxin genes namely- alpha toxin gene (cpa, beta toxin gene (cpb, epsilon toxin gene (etx, iota toxin gene (iA in a Thermal Cycler. Isolates were also screened for the presence of enterotoxin gene (cpe and beta2 toxin gene (cpb2 by single step PCR. Biochemical tests and phenotypic determination of virulence factors tentatively identified 82 (27.24% isolates of C. perfringens. In PCR assay, all 82 (100% isolates harbored cpa toxin genes of C. perfringens, however, 65 (79.26% isolates also carried additional cpb2 toxin genes. None of the isolates were found positive for beta, epsilon, iota and enterotoxin genes. Genotyping of the 82 isolates by PCR revealed that all the isolated bacteria were belonged to C. perfringens type A and both cpa and cpb2 toxin genes were prevalent among the isolates of C. perfringens type A, impending the risk of pathogenicity to human via freshwater fish and fish pickles.

  3. Detection of Different Genotypes of Clostridium perfringens in Feces of Healthy Dairy Cattle from China using Real-Time Duplex PCR Assay

    Directory of Open Access Journals (Sweden)

    Guanghua Wang, Jizhang Zhou, Fuying Zheng, Guozhen Lin, Xiaoan Cao, Xiaowei Gong and Changqing Qiu*

    2011-04-01

    Full Text Available Dual-labeled fluorescence hybridization probe-based multiplex quantitative real-time polymerase chain reaction (qPCR assay was used for the detection of Clostridium perfringens toxin genes alpha (cpa, beta (cpb, iota (ia, epsilon (etx, beta2 (cpb2 and enterotoxin (cpe directly from the feces of cattle. Fecal samples from 261 lactating cattle, belonging to three dairy herds in Ningxia (China, were examined using the developed assays. The duplex qPCR assay revealed that cpa, etx, cpb2 and cpe toxin genes were detected in 176 (100%, 15 (8.5%, 142 (80.7% and 4 (2.3% of 176 PCR positive samples, respectively. The findings of this study revealed that C. perfringens beta2-toxin-producing strains were widely prevalent in lactating cows in Ningxia, possibly playing an important role in C. perfringens-associated diarrheal disease.

  4. 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.

  5. Genotypic and phenotypic characterization of Clostridium perfringens isolates from Darmbrand cases in post-World War II Germany.

    Science.gov (United States)

    Ma, Menglin; Li, Jihong; McClane, Bruce A

    2012-12-01

    Clostridium perfringens type C strains are the only non-type-A isolates that cause human disease. They are responsible for enteritis necroticans, which was termed Darmbrand when occurring in post-World War II Germany. Darmbrand strains were initially classified as type F because of their exceptional heat resistance but later identified as type C strains. Since only limited information exists regarding Darmbrand strains, this study genetically and phenotypically characterized seven 1940s era Darmbrand-associated strains. Results obtained indicated the following. (i) Five of these Darmbrand isolates belong to type C, carry beta-toxin (cpb) and enterotoxin (cpe) genes on large plasmids, and express both beta-toxin and enterotoxin. The other two isolates are cpe-negative type A. (ii) All seven isolates produce highly heat-resistant spores with D(100) values (the time that a culture must be kept at 100°C to reduce its viability by 90%) of 7 to 40 min. (iii) All of the isolates surveyed produce the same variant small acid-soluble protein 4 (Ssp4) made by type A food poisoning isolates with a chromosomal cpe gene that also produce extremely heat-resistant spores. (iv) The Darmbrand isolates share a genetic background with type A chromosomal-cpe-bearing isolates. Finally, it was shown that both the cpe and cpb genes can be mobilized in Darmbrand isolates. These results suggest that C. perfringens type A and C strains that cause human food-borne illness share a spore heat resistance mechanism that likely favors their survival in temperature-abused food. They also suggest possible evolutionary relationships between Darmbrand strains and type A strains carrying a chromosomal cpe gene.

  6. Oral Administration of Recombinant Saccharomyces boulardii Expressing Ovalbumin-CPE Fusion Protein Induces Antibody Response in Mice.

    Science.gov (United States)

    Bagherpour, Ghasem; Ghasemi, Hosnie; Zand, Bahare; Zarei, Najmeh; Roohvand, Farzin; Ardakani, Esmat M; Azizi, Mohammad; Khalaj, Vahid

    2018-01-01

    Saccharomyces boulardii , a subspecies of Saccharomyces cerevisiae , is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi ® ) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3 - S. boulardii . To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group ( P boulardii or PBS), and the fecal IgA titer was significantly higher in test group ( P boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii , as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins.

  7. Mechanisms of Action and Cell Death Associated with Clostridium perfringens Toxins

    Directory of Open Access Journals (Sweden)

    Mauricio A. Navarro

    2018-05-01

    Full Text Available Clostridium perfringens uses its large arsenal of protein toxins to produce histotoxic, neurologic and intestinal infections in humans and animals. The major toxins involved in diseases are alpha (CPA, beta (CPB, epsilon (ETX, iota (ITX, enterotoxin (CPE, and necrotic B-like (NetB toxins. CPA is the main virulence factor involved in gas gangrene in humans, whereas its role in animal diseases is limited and controversial. CPB is responsible for necrotizing enteritis and enterotoxemia, mostly in neonatal individuals of many animal species, including humans. ETX is the main toxin involved in enterotoxemia of sheep and goats. ITX has been implicated in cases of enteritis in rabbits and other animal species; however, its specific role in causing disease has not been proved. CPE is responsible for human food-poisoning and non-foodborne C. perfringens-mediated diarrhea. NetB is the cause of necrotic enteritis in chickens. In most cases, host–toxin interaction starts on the plasma membrane of target cells via specific receptors, resulting in the activation of intracellular pathways with a variety of effects, commonly including cell death. In general, the molecular mechanisms of cell death associated with C. perfringens toxins involve features of apoptosis, necrosis and/or necroptosis.

  8. Toxin genotyping of Clostridium perfringens strains using a polymerase chain reaction protocol

    Directory of Open Access Journals (Sweden)

    Elisabetta Di Giannatale

    2010-03-01

    Full Text Available A polymerase chain reaction protocol consisting of a multiplex to identify the cpa, cpb1, cpetx, cpi genes and a duplex to identify the cpe and cpb2 genes encoding for a, b1, e, i, enterotoxin and b2 toxins, respectively, was applied to DNA extracted from two collections of Clostridium perfringens strains. The first collection involved 19 isolates from rabbits. The second collection of 41 isolates came from routine necropsies. The cpa gene alone, or in association with the cpb2 gene, was detected in all DNA samples examined. The cpa gene, together with cpb2 gene, were detected in seven of the rabbit C. perfringens strains (36.8% and in nine isolates from necropsies (21.9%. The cpa gene was found in 63.2% of rabbit strains and 76.9% of strains from other animal species. In rabbits, the pathological lesions associated with C. perfringens detection were predominantly forms of non-inflammatory enteropathies. In other species, C. perfringens was mainly associated with congestive-haemorrhagic enteropathy, but also with fatal traumatic lesions, degenerative diseases and organs with post-mortem autolysis. No clear correlation was observed between detection of b2 toxin gene and species-specific pathological features.

  9. Molecular typing of Clostridium perfringens isolated from swine in slaughterhouses from São Paulo State, Brazil Tipagem molecular de Clostridium perfringens isolados de suínos em abatedouros do estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Thais Sebastiana Porfida Ferreira

    2012-08-01

    Full Text Available Clostridium perfringens is an anaerobic Gram-positive bacterium known as common pathogen for humans, for domestic and wildlife animals. Although infections caused by C. perfringens type C and A in swine are well studied, just a few reports describe the genetic relationship among strains in the epidemiological chain of swine clostridioses, as well as the presence of the microorganism in the slaughterhouses. The aim of the present study was to isolate C. perfringens from feces and carcasses from swine slaughterhouses, characterize the strains in relation to the presence of enterotoxin, alpha, beta, epsilon, iota and beta-2 toxins genes, using polymerase chain reaction (PCR and comparing strains by means of Pulsed field gel electrophoresis (PFGE. Clostridium perfringens isolation frequencies in carcasses and finishing pig intestines were of 58.8% in both types of samples. According to the polymerase chain reaction assay, only alfa toxin was detected, being all isolates also negative to enterotoxin and beta2 toxin. Through PFGE technique, the strains were characterized in 35 pulsotypes. In only one pulsotype, the isolate from carcass sample was grouped with fecal isolate of the same animal, suggesting that the risk of cross-contamination was low. Despite the high prevalence of C. perfringens in swine carcasses from the slaughterhouses assessed, the risk of food poisoning to Brazilian pork consumers is low, since all strains were negative to cpe-gene, codifying enterotoxin.Clostridium perfringens é uma bactéria Gram positiva anaeróbica, conhecida por infectar os seres humanos, animais domésticos e de vida selvagem. Apesar de as infecções causadas por C. perfringens tipo C e A em suínos serem bastante estudadas, poucos relatos descrevem a relação genética entre as linhagens envolvidas na cadeia epidemiológica da clostridiose suína, bem como a presença do microorganismo em abatedouros. O objetivo do presente estudo foi isolar C

  10. Oral Administration of Recombinant Saccharomyces boulardii Expressing Ovalbumin-CPE Fusion Protein Induces Antibody Response in Mice

    Directory of Open Access Journals (Sweden)

    Ghasem Bagherpour

    2018-04-01

    Full Text Available Saccharomyces boulardii, a subspecies of Saccharomyces cerevisiae, is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi® was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA, was prepared and transformed into the ura3- S. boulardii. To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group (P < 0.001 compared to control groups (receiving wild type S. boulardii or PBS, and the fecal IgA titer was significantly higher in test group (P < 0.05 than control groups. In parallel, a recombinant S. boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii, as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic

  11. Caracterización molecular y resistencia antimicrobiana de aislamientos de Clostridium perfringens de diferentes orígenes en Costa Rica

    Directory of Open Access Journals (Sweden)

    María del Mar Gamboa-Coronado

    2011-12-01

    production of four major toxins α, β, ε and ι, C. perfringens is classified into five toxinotypes (A-E. Some strains produce an enterotoxin (CPE, encoded by the cpe gene, which causes diarrhea in humans and some animals. C. perfringens strains that had been previously isolated and been kept at -80°C were analyzed for the presence of toxin genes and for antimicrobial resistance: 20 from soils,20 from animal, 20 from human origin and 21 from food non related to outbreaks. According to PCR results, all strains were classified as C. perfringens type A, since only α toxin gene was detected, while cpe was detected in two strains (2.5% isolated from food, as it has been described in other world regions. Antibiotic resistance to at least one antibiotic was detected in 44% of the strains, 41% was resistant to clindamycin, 25% to chloramphenicol, 22% to penicillin and 20% to metronidazole. Soils strains showed the highest resistance percentages to almost all antibiotics. Multiresistance (to three or more antibiotic groups was detected in the strains from soil (40%, human origin (30%, food (14% and animal origin (5%. The high resistance rates found may be explained by the widespread use of antimicrobials as growth promoters in plants and animals; also these resistant strains may act as reservoir of resistance genes that may be transferred between bacteria in different environments. Rev. Biol. Trop. 59 (4: 1479-1485. Epub 2011 December 01.

  12. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors

    Directory of Open Access Journals (Sweden)

    Raymond Kiu

    2017-12-01

    Full Text Available Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an “open” pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens-associated exotoxins genes including α-toxin (plc, enterotoxin (cpe, and Perfringolysin O (pfo or pfoA, although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56 of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes (tet and anti-defensins genes (mprF were consistently detected in silico (tet: 75%; mprF: 100%. However, pre-antibiotic era strain genomes did not encode for tet, thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  13. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors.

    Science.gov (United States)

    Kiu, Raymond; Caim, Shabhonam; Alexander, Sarah; Pachori, Purnima; Hall, Lindsay J

    2017-01-01

    Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an "open" pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene) in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens -associated exotoxins genes including α-toxin ( plc ), enterotoxin ( cpe ), and Perfringolysin O ( pfo or pfoA ), although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56) of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes ( tet ) and anti-defensins genes ( mprF ) were consistently detected in silico ( tet : 75%; mprF : 100%). However, pre-antibiotic era strain genomes did not encode for tet , thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  14. Clostridium perfringens Sporulation and Sporulation-Associated Toxin Production

    Science.gov (United States)

    Li, Jihong; Paredes-Sabja, Daniel; Sarker, Mahfuzur R.; McClane, Bruce A.

    2015-01-01

    The ability of Clostridium perfringens to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the spores produced by food poisoning strains are often exceptionally resistant to food environment stresses such as heat, cold and preservatives, which likely facilitates their survival in temperature-abused foods. The exceptional resistance properties of spores made by most type A food poisoning strains and some type C foodborne disease strains involves their production of a variant small acid soluble protein-4 that binds more tightly to spore DNA compared to the small acid soluble protein-4 made by most other C. perfringens strains. Sporulation and germination by C. perfringens and Bacillus spp. share both similarities and differences. Finally, sporulation is essential for production of C. perfringens enterotoxin, which is responsible for the symptoms of C. perfringens type A food poisoning, the second most common bacterial foodborne disease in the USA. During this foodborne disease, C. perfringens is ingested with food and then, using sporulation-specific alternate sigma factors, this bacterium sporulates and produces the enterotoxin in the intestines. PMID:27337447

  15. Clostridium perfringens in London, July 2009: two weddings and an outbreak.

    OpenAIRE

    Eriksen, J.; Zenner, D.; Anderson, S. R.; Grant, K.; Kumar, D.

    2010-01-01

    : Food poisoning outbreaks caused by Clostridium perfringens enterotoxin occur occasionally in Europe but have become less common in recent years. This paper presents the microbiological and epidemiological results of a large C. perfringens outbreak occurring simultaneously at two weddings that used the same caterer. The outbreak involved several London locations and required coordination across multiple agencies. A case-control study (n=134) was carried out to analyse possible associations b...

  16. Toxin genotyping of Clostridium perfringens field strains isolated from healthy and diseased chickens

    Directory of Open Access Journals (Sweden)

    Luca Bano

    2010-01-01

    Full Text Available Clostridium perfringens is well known as the aetiological agent of necrotic enteritis in chicken. Type A and type C are considered the C. perfringens toxin types responsible for this disease. The aim of this study was to determine the presence of genes coding for α, β, ε, ι, β2 and enterotoxin in C. perfringens field strains collected from healthy and diseased chickens. Thirty-seven C. perfringens field strains were toxin typed: all strains resulted to be toxin type A and 3 of these tested positive for the presence of the toxin β2 coding gene. Four isolates showed the cpa gene with the insertion of a group II intron. Our findings confirm the most recent results reported from different countries and the data suggest that the role of C. perfringens type C should be revaluated in the etiopathogenesis of necrotic enteritis.

  17. Application of the CPE-air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Van Hest, J.; Van der Neut, R.P.; Wijnstra, K.P.

    1986-09-01

    Described is an air conditioning system with a special cooling unit, CPE (combined dew point and heat exchanger). The system has been installed for the first time in the Netherlands in a shop in Utrecht. Results of measurements during September 1985 are presented. 7 figs.

  18. Clostridium perfringens in London, July 2009: two weddings and an outbreak.

    Science.gov (United States)

    Eriksen, J; Zenner, D; Anderson, S R; Grant, K; Kumar, D

    2010-06-24

    Food poisoning outbreaks caused by Clostridium perfringens enterotoxin occur occasionally in Europe but have become less common in recent years. This paper presents the microbiological and epidemiological results of a large C. perfringens outbreak occurring simultaneously at two weddings that used the same caterer. The outbreak involved several London locations and required coordination across multiple agencies. A case-control study (n=134) was carried out to analyse possible associations between the food consumed and becoming ill. Food, environmental and stool samples were tested for common causative agents, including enterotoxigenic C. perfringens. The clinical presentation and the epidemiological findings were compatible with C. perfringens food poisoning and C. perfringens enterotoxin was detected in stool samples from two cases. The case-control study found statistically significant associations between becoming ill and eating either a specific chicken or lamb dish prepared by the same food handler of the implicated catering company. A rapid outbreak investigation with preliminary real-time results and the successful collaboration between the agencies and the caterer led to timely identification and rectification of the failures in the food handling practices.

  19. Isolation, molecular characterization and prevalence of Clostridium perfringens in sheep and goats of Kashmir Himalayas, India

    Directory of Open Access Journals (Sweden)

    Salik Nazki

    2017-12-01

    Full Text Available Aim: The study was conducted to report the occurrence of the Clostridium perfringens in sheep and goats of the Kashmir valley for the 1st time and to characterize them molecularly with respect to toxin genes to determine the prevalence of the various toxinotypes. Materials and Methods: A total of 177 samples (152 from sheep and 25 from goats collected from healthy, diarrheic animals, and morbid material of animals suspected to have died of enterotoxaemia were screened for C. perfringens toxinotypes. The presumptive positive isolates were confirmed using 16S rRNA gene-based polymerase chain reaction (PCR. All the confirmed isolates were screened for six toxin genes, namely; cpa, cpb, etx, cpi, cpb2, and cpe using a multiplex PCR. Results: The PCR amplification of 16S rRNA gene revealed that out of 177 samples collected, 125 (70.62% were found positive for C. perfringens, of which 110 (72.36% were from sheep and 15 (60% were from goats. The highest prevalence of C. perfringens toxinotype D was observed in lambs (56.16% and kids (46.16% followed by 3.84% in adult sheep while it was absent in samples obtained from adult goats. The multiplex PCR revealed that 67 (60.90% isolates from sheep and 8 (53.33% isolates from goats belonged to toxinotype A, while 43 (39.09% isolates from sheep and 7 (46.66% isolates from goats were detected as toxinotype D. None of the isolates was found to be toxinotype B, C, or E. All the C. perfringens toxinotype A isolates from sheep were negative for both cpb2 and cpe genes, however, 27.90% toxinotype D isolates from sheep carried cpb2 gene, and 6.97% possessed cpe gene. In contrast, 12.50% C. perfringens toxinotype A isolates from goats harbored cpb2 and cpe genes while 14.28% isolates belonging to toxinotype D carried cpb2 and cpe genes, respectively. Conclusion: The high prevalence of C. perfringens was observed, even in day-old lambs. The toxinotypes A and D are prevalent in both sheep and goats. The severity of

  20. Toxinotyping of Clostridium perfringens strains isolated from packed chicken portions

    Directory of Open Access Journals (Sweden)

    Maryam Poursoltani

    2014-06-01

    Full Text Available Background and Aim: Clostridium perfringens are classified into five toxin types A to E, on the basis of production of Alpha, Beta, Epsilon and Iota toxins. Some strains are able to produce enterotoxin, can cause food poisoning in human. The bacteria are able to produce NetB and TpeL toxins which are virulence factors in necrotic enteritis in poultry. The aim of this study was to determine the toxin profile of C. perfringens strains isolated from packed chicken portions using Single and Multiplex PCR assays. Materials and Methods: In a crossectional study, 180 sample of chicken portions including wing (n=50, liver (n=50, neck (n=50 and gizzard (n=30 were collected randomly and examined for C. perfringens contamination. For this purpose all of samples were cultured on the 7% sheep defibrinated blood agar, TSN and TSC culture media. All of the isolates were investigated for the presence of alpha, beta, epsilon, iota toxin and virulence (tpeL and netB genes. Results: In the present study, 6 isolates out of 180 samples, were confirmed as C. perfringens by culture and molecular methods. All of the isolates (100% were confirmed as cpa and cpb positive strains and belong to type C of C. perfringens. The netB gene was detected in 5 isolates (83.33% and tpeL gene in three isolates (50%. Conclusions: Our findings show the majority of C. perfringens in broilers are belong to type C which produce necrotic enteritis in poultry and may be transmitted to human through poultry products.

  1. Multidrug resistance in Clostridium perfringens isolated from diarrheal neonatal piglets in Thailand.

    Science.gov (United States)

    Ngamwongsatit, Bhinyada; Tanomsridachchai, Wimonrat; Suthienkul, Orasa; Urairong, Supanee; Navasakuljinda, Wichian; Janvilisri, Tavan

    2016-04-01

    Clostridium perfringens causes diarrhea in neonatal piglets, thereby affecting commercial swine farming. The objective of this study was to determine the prevalence and characterize antimicrobial resistance in C. perfringens isolated from diarrheal neonatal piglets in Thailand. A total of 260 rectal swab samples were collected from 13 farms and were subjected to C. perfringens isolation. A total of 148 samples were PCR-positive for C. perfringens toxin genes, from which 122 were recovered. All isolates were cpb2-encoding C. perfringens type A and enterotoxin gene negative. Most of the isolates were susceptible to ampicillin, bacitracin, chlorotetracycline, doxycycline, and oxytetracycline with MIC50 values ranging from 0.32 to 8 μg/ml. The high resistance rates were observed for ceftiofur, enrofloxacin, erythromycin, lincomycin, and tylosin. Among resistant isolates, 82% were resistant to more than one type of antibiotics. The distinct pattern of multiple drug resistance in C. perfringens was observed in different regions, potentially reflecting the farm specific usage of these agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Embryonated chicken eggs as an alternative model for mixed Clostridium perfringens and Eimeria tenella infection in chickens.

    Science.gov (United States)

    Alnassan, Alaa Aldin; Shehata, Awad Ali; Kotsch, Marianne; Lendner, Matthias; Daugschies, Arwid; Bangoura, Berit

    2013-06-01

    The chorioallantoic membrane (CAM) of chicken embryo eggs is a suitable model for viral and bacterial infections. In the present study, a new approach for testing the pathogenesis and virulence of Clostridium perfringens and Eimeria tenella dual infections as a model using the CAM of embryonated chicken eggs was developed. For this purpose, 24 specific pathogen-free (SPF) embryonated chicken eggs were divided into four groups (n = 6) and designated group E, group CP, group CPE, and NC. Sporozoites of E. tenella (20,000 sporozoites) were inoculated into 10-day-old embryonated SPF chicken eggs (groups E and CPE) via allantoic sac route. At 15-day-old, eggs of groups CP and CPE were infected with 10 (4)  cfu C. perfringens via the same route. Assessment of pathogenicity was assessed using gross and histopathological lesions. Embryo mortality reached 17 % after mono-infection with C. perfringens and/or E. tenella and 50 % in the mixed-infected group. Lesions in the CAMs were most numerous and most severe in co-infected eggs (group CPE), reaching the maximum score of 3 in 50 % of the inoculated eggs (P < 0.01). In Eimeria spp.-infected eggs (group E), lesions of score were between 1 and 2. Mono-infection with C. perfringens did not lead to a significant occurrence of lesions. Histopathological investigations of the CAM revealed clusters of Gram-positive bacteria, infiltration with leukocytes, lymphocytes, and developmental stages of E. tenella in the co-infected group. These data suggest that embryonated eggs could be an in ovo model for studying the pathogenesis of mixed infection with Eimeria and C. perfringens.

  3. Tips to Prevent Illness from Clostridium Perfringens

    Science.gov (United States)

    ... Some strains produce a toxin that causes diarrhea. What are common food sources of C. perfringens ? Meat and poultry are ... Anyone can get food poisoning from C. perfringens . What are the symptoms of C. perfringens food poisoning? People with C. perfringens food poisoning develop ...

  4. Evaluation of PCR and DNA hybridization protocols for detection of viable enterotoxigenic Clostridium perfringens in irradiated beef

    International Nuclear Information System (INIS)

    Baez, L.A.; Juneja, V.K.; Thayer, D.W.; Sackitey, S.

    1997-01-01

    The sensitivity of DNA hybridization and polymerase chain reaction (PCR), was evaluated in irradiated cooked and raw beef samples. A membrane-based colony hybridization assay and a PCR protocol, both with specificity for the enterotoxin A gene of Clostridium perfringens, were compared with viable plate counts. The results of the colony hybridization procedure were in agreement with viable plate counts for detection and enumeration of enterotoxigenic C. perfringens. The PCR procedure combined a 4 h enrichment followed by a nucleic acid extraction step and assessed the amplification of 183 and 750 base pair enterotoxin gene targets. Detection of C. perfringens by PCR did not show a reliable correlation with viable plate counts or the colony hybridization assay. C. perfringens killed by irradiation were not detected by the plate count or colony hybridization methods; however, killed cells were detected with the PCR technique. By relying on the growth of viable cells for detection and/or enumeration, the colony hybridization and plate count methods provided a direct correlation with the presence of viable bacteria

  5. Incidence of Clostridium perfringens in Broiler Chickens in the Czech Republic

    Directory of Open Access Journals (Sweden)

    I. Svobodová

    2007-01-01

    Full Text Available Clostridium perfringens is a causative agent of human and animal foodborne diseases. It is known as a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen causing necrotic enteritis. The aim of the present study was to detect the incidence of C. perfringens in healthy broiler chickens. From May 2005 to September 2006, 609 samples of caecal content from broilers from 23 intensive poultry farms were analyzed. The samples were cultivated on TSC and blood agar, typical colonies were identified and biochemically confirmed. the total number of positive samples was 112 (18.39%. the samples were processed by the multiplex polymerase chain reaction method (PCR for toxin genotyping. The presence of alpha, beta, beta2 and enterotoxin gene was detected. All C. perfringens isolates were classified as type A, four isolates had the cpb2 gene. In conclusion the prevalence of C. perfringens-positive farms is approximately 74% and the amount ranges about 104 cfu/g of caecal content.

  6. Characterization of Clostridium perfringens isolates from healthy turkeys and from turkeys with necrotic enteritis

    DEFF Research Database (Denmark)

    Lyhs, Ulrike; Perko-Mäkelä, P.; Kallio, H.

    2013-01-01

    from 1998 to 2012. Furthermore, C. perfringens isolates from healthy and diseased turkeys were characterized and their genetic diversity was investigated using pulsed-field gel electrophoresis (PFGE). Isolates (n = 212) from birds with necrotic gut lesions and from healthy flocks of 30 commercial...... turkey farms were characterized for the presence of cpa, cpb, iA, etx, cpb2, and cpe and netB genes. A total of 93 C. perfringens isolates, including 55 from birds with necrotic gut lesions and 38 from healthy birds from 13 different farms, were analyzed with PFGE. All contract turkey farmers (n = 48......) of a turkey company that produces 99% of domestic turkey meat in Finland were interviewed about background information, management at the farm, and stress factors related to NE outbreaks. Pulsed-field gel electrophoresis analysis with SmaI restriction enzyme resulted in 30 PFGE patterns among the 92 C...

  7. Optimization of the use of carbon paste electrodes (CPE for electrochemical study of the chalcopyrite

    Directory of Open Access Journals (Sweden)

    Daniela G. Horta

    2009-01-01

    Full Text Available The use of carbon paste electrodes (CPE of mineral sulfides can be useful for electrochemical studies to overcome problems by using massive ones. Using CPE-chalcopyrite some variables were electrochemically evaluated. These variables were: (i the atmosphere of preparation (air or argon of CPE and elapsed time till its use; (ii scan rate for voltammetric measurements and (iii chalcopyrite concentration in the CPE. Based on cyclic voltammetry, open-circuit potential and electrochemical impedance results the recommendations are: oxygen-free atmosphere to prepare and kept the CPE until around two ours, scan rates from 10 to 40 mV s-1, and chalcopyrite concentrations > 20%.

  8. Toxinotyping and antimicrobial susceptibility of enterotoxigenic Clostridium perfringens isolates from mutton, beef and chicken meat.

    Science.gov (United States)

    Khan, Madiha; Nazir, Jawad; Anjum, Aftab Ahmad; Ahmad, Mansur-Ud-Din; Nawaz, Muhammad; Shabbir, Muhammad Zubair

    2015-08-01

    A total of 300 meat samples comprising mutton, beef, and chicken meat (n = 100) collected from either local butcher shops or large meat outlets situated at various areas of Lahore City located in Punjab province of Pakistan were tested for the isolation of Clostridium perfringens. Prevalence of the organism was highest in the chicken (6 %) followed by mutton (5 %) and beef (1 %). Contamination level was high (10/150) in the samples collected from local butcher shops in comparison to the samples collected from large meat outlets (2/150). All of the raw meat samples were negative for the presence of alpha, beta and epsilon toxins of C. perfringens as detected through ELISA. Out of a total number of 12 isolates only half were capable of producing enterotoxins when cultured in trypticase glucose yeast (TGY) broth. Toxinotyping of the isolates showed that 3 were of type A while one each of the remaining three belonged to type B, C, and D. Antibiotic susceptibility testing of the toxin producing isolates revealed that C. perfringens were susceptible to chloramphenicol, ciprofloxacin, metronidazole, and ceftriaxone. All of the other drugs were relatively less effective with a least activity of amoxicillin against the isolates.

  9. Transcriptional Profile during Deoxycholate-Induced Sporulation in a Clostridium perfringens Isolate Causing Foodborne Illness.

    Science.gov (United States)

    Yasugi, Mayo; Okuzaki, Daisuke; Kuwana, Ritsuko; Takamatsu, Hiromu; Fujita, Masaya; Sarker, Mahfuzur R; Miyake, Masami

    2016-05-15

    Clostridium perfringens type A is a common source of foodborne illness (FBI) in humans. Vegetative cells sporulate in the small intestinal tract and produce the major pathogenic factor C. perfringens enterotoxin. Although sporulation plays a critical role in the pathogenesis of FBI, the mechanisms inducing sporulation remain unclear. Bile salts were shown previously to induce sporulation, and we confirmed deoxycholate (DCA)-induced sporulation in C. perfringens strain NCTC8239 cocultured with human intestinal epithelial Caco-2 cells. In the present study, we performed transcriptome analyses of strain NCTC8239 in order to elucidate the mechanism underlying DCA-induced sporulation. Of the 2,761 genes analyzed, 333 were up- or downregulated during DCA-induced sporulation and included genes for cell division, nutrient metabolism, signal transduction, and defense mechanisms. In contrast, the virulence-associated transcriptional regulators (the VirR/VirS system, the agr system, codY, and abrB) were not activated by DCA. DCA markedly increased the expression of signaling molecules controlled by Spo0A, the master regulator of the sporulation process, whereas the expression of spo0A itself was not altered in the presence or absence of DCA. The phosphorylation of Spo0A was enhanced in the presence of DCA. Collectively, these results demonstrated that DCA induced sporulation, at least partially, by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes in strain NCTC8239 while altering the expression of various genes. Disease caused by Clostridium perfringens type A consistently ranks among the most common bacterial foodborne illnesses in humans in developed countries. The sporulation of C. perfringens in the small intestinal tract is a key event for its pathogenesis, but the factors and underlying mechanisms by which C. perfringens sporulates in vivo currently remain unclear. Bile salts, major components of bile, which is secreted from the liver for

  10. Optimizing sporulation of Clostridium perfringens

    NARCIS (Netherlands)

    Jong, de A.E.I.; Beumer, R.R.; Rombouts, F.M.

    2002-01-01

    Many sporulation media have been developed for Clostridium perfringens, but none stimulates sporulation for all strains. The aim of our experiments was to develop a sporulation method using Duncan and Strong (DS) medium, which supports sporulation of a wide variety of strains. Different inoculation

  11. Toxinas de Clostridium perfringens Toxins of Clostridium perfringens

    Directory of Open Access Journals (Sweden)

    W. E. Morris

    2009-12-01

    Full Text Available Clostridium perfringens es un bacilo grampositivo anaerobio con capacidad de formar esporas. Es uno de los patógenos bacterianos con mayor distribución en el medio ambiente, ya que puede ser aislado de muestras de suelo y de agua y además forma parte de la microbiota intestinal de animales y humanos. Sin embargo, en ciertas ocasiones puede actuar como patógeno oportunista y causar enfermedades como la gangrena gaseosa, la enterotoxemia del ovino y del caprino y la disentería del cordero, entre otras. En humanos, está asociado a enfermedades como la intoxicación por alimentos, la enterocolitis necrotizante en niños y la enteritis necrótica o pigbel de las tribus de Papúa-Nueva Guinea. El renovado interés que existe actualmente en el estudio de C. perfringens como patógeno veterinario y humano, junto con el avance de la biología molecular, han hecho posible que la ciencia tenga hoy un conocimiento más profundo sobre la biología y la patogenia de esta bacteria. En esta revisión bibliográfica se discuten y actualizan los principales aspectos de la patogenia intestinal de C. perfringens teniendo en cuenta las toxinas con mayor importancia médica descritas hasta el presente.Clostridium perfringens is an anaerobic gram-positive spore-forming bacillus. It is one of the pathogens with larger distribution in the environment; it can be isolated from soil and water samples, which also belongs to the intestinal flora of animals and humans. However, on some occasions it can act as an opportunistic pathogen, causing diseases such as gas gangrene, enterotoxemia in sheep and goats and lamb dysentery, among others. In human beings, it is associated to diseases such as food poisoning, necrotic enterocolitis of the infant and necrotic enteritis or pigbel in Papua-New Guinea tribes. The renewed interest existing nowadays in the study of C. perfringens as a veterinarian and human pathogen, together with the advance of molecular biology, had enabled

  12. Behavior of Clostridium perfringens at low temperatures

    NARCIS (Netherlands)

    Jong, de A.E.I.; Rombouts, F.M.; Beumer, R.R.

    2004-01-01

    Refrigerated storage is an important step in the preparation of foods and inadequate storage is one of the main causes of food poisoning outbreaks of Clostridium perfringens. Therefore, growth and germination characteristics of C. perfringens in a temperature range of 3-42 degreesC were determined

  13. Double antibody solid-phase radioimmunoassay for staphylococcal enterotoxin A

    International Nuclear Information System (INIS)

    Lindroth, S.; Niskanen, A.

    1977-01-01

    A double antibody solid-phase (DASP) radioimmunoassay for staphylococcal enterotoxin A is described. In the assay the antigen-antibody complex is precipitated by anti-rabbit serum which is adsorbed onto a solid carrier (cellulose). The method is sensitive to 200 pg of enterotoxin. It was possible to detect a little as 2-5 ng of enterotoxin A/ml food extract from minced meat and sausage. Enterotoxins B and C were not found to inhibit the uptake of labled enterotoxin A at a level which might distort the results of the enterotoxin A assay. The DASP technique is sensitive, rapid, and easy to perform and thus compares favorably with other radioimmunoassays for enterotoxin. (orig.) [de

  14. Staphylococcal aureus Enterotoxin C and Enterotoxin-Like L Associated with Post-partum Mastitis

    DEFF Research Database (Denmark)

    Franck, Kristina T; Gumpert, Heidi; Olesen, Bente

    2017-01-01

    between isolates from the two outbreaks revealed a S. aureus pathogenicity island containing enterotoxin C and enterotoxin-like L only in isolates from outbreak 2. Enterotoxin C and enterotoxin-like L carrying S. aureus are associated with bovine mastitis and our findings indicate that these may also...... PVL and ACME negative. In outbreak 1, the isolates harbored SCCmec IVa and in outbreak 2 SCCmec V. The clinical presentation differed between the two outbreaks, as none of five MRSA positive mothers in outbreak 1 had mastitis vs. five of six MRSA positive mothers in outbreak 2 (p ....02). To investigate if whole-genome sequencing could identify virulence genes associated with mastitis, t015:ST45 isolates from Denmark (N = 101) were whole-genome sequenced. Sequence analysis confirmed two separate outbreaks with no sign of sustained spread into the community. Analysis of the accessory genome...

  15. Upregulation of CPE promotes cell proliferation and tumorigenicity in colorectal cancer

    International Nuclear Information System (INIS)

    Liang, Xing-Hua; He, Wen-guang; Huang, Yan-Nian; Zeng, Xian-Cheng; Li, Ling-ling; Wu, Geng-Gang; Xie, Yi-Cheng; Zhang, Guang-Xian; Chen, Wei; Yang, Hai-Feng; Liu, Qi-Long; Li, Wen-Hong

    2013-01-01

    Colorectal cancer (CRC) is one of the most common cancers worldwide and a leading cause of cancer related death. Although the mortality rate of CRC is decreasing, finding novel targets for its therapy remains urgent. Carboxypeptidase E (CPE), a member of the pro-protein convertases, which are involved in the maturation of protein precursors, has recently been reported as elevated in many types of cancer. However, its role and mechanisms in tumor progression are poorly understood. In the present study, we investigated expression of CPE in CRC cell lines and tumor tissues using Western blot and real-time qRT-PCR. Plasmids for overexpression and depletion of CPE were constructed and analyzed by Western blot, MTT and colony formation assays and bromodeoxyuridine incorporation assays. The relative expression of p21, p27, and cyclin D1 were analyzed by Real-time qRT-PCR in the indicated cells. Our study showed that CPE was significantly upregulated in CRC cell lines and tumor tissues. MTT and colony formation assays indicated that overexpression of CPE enhanced cell growth rates. BrdU incorporation and flow-cytometry assays showed that ectopic expression of CPE increased the S-phase fraction cells. Soft agar assay proved enhanced tumorigenicity activity in CPE over-expressing CRC cells. Further studies of the molecular mechanisms of CPE indicated that is promoted cell proliferation and tumorigenicity through downregulation of p21 and p27, and upregulation of cyclin D1. Taken together, these data suggest that CPE plays an important role in cell cycle regulation and tumorigenicity, and may serve as a potential target for CRC therapeutics

  16. Staphylococcus aureus enterotoxins A- and B

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Karlsdóttir, Edda

    2013-01-01

    Enterotoxins of Staphylococcus aureus are among the most common causes of food poisoning. Acting as superantigens they intoxicate the organism by causing a massive uncontrolled T cell activation that ultimately may lead to toxic shock and death. In contrast to our detailed knowledge regarding...

  17. Caracterización molecular y resistencia antimicrobiana de aislamientos de Clostridium perfringens de diferentes orígenes en Costa Rica

    Directory of Open Access Journals (Sweden)

    María del Mar Gamboa-Coronado

    2011-12-01

    Full Text Available Clostridium perfringens es un bacilo Gram positivo, esporulado, anaerobio, ampliamente distribuido en la naturaleza, que produce cuatro toxinas principales α, β, ε y ι, las cuales permiten su clasificación en cinco toxinotipos (A-E. Algunas cepas producen una enterotoxina (CPE, codificada por el gen cpe, que causa diarrea en seres humanos y en algunos animales. La presencia de los genes de estas toxinas y la sensibilidad a los antibióticos se determinó en 81 cepas de C. perfringens previamente aisladas y que habían sido mantenidas a -80°C; 20 de suelos, 20 de origen animal, 20 de origen humano y 21 de alimentos cocidos no relacionados con brotes alimentarios. De acuerdo con los resultados de PCR, todas las cepas fueron clasificadas como C. perfringens tipo A, debido a que solo se les detectó el gen de la toxina α, mientras que el gen de la enterotoxina (cpe se detectó en dos cepas (2.5% aisladas de alimentos, tal como ha sido descrito en otras regiones del mundo. El 44% de las cepas fue resistente a algún antibiótico; clindamicina (41%, cloranfenicol (25%, penicilina (22% y metronidazol (20%. En general, las cepas provenientes de suelos presentaron los mayores porcentajes de resistencia a casi todos los antibióticos. El 40% de las cepas de suelo presentó multiresistencia (a tres o más grupos de antibióticos, el 30% de las de origen humano, el 14% de las de alimentos y el 5% de las de origen animal. Las altas tasas de resistencia encontradas podrían deberse al amplio uso de antibióticos como promotores de crecimiento de plantas y animales y esas cepas resistentes podrían actuar como reservorio de genes de resistencia que pueden transferirse entre bacterias de diversos ambientes.

  18. Critically Engaging "Mutually Engaged Supervisory Processes": A Proposed Theory for CPE Supervisory Education.

    Science.gov (United States)

    Fitchett, George; Altenbaumer, Mary L; Atta, Osofo Kwesi; Stowman, Sheryl Lyndes; Vlach, Kyle

    2014-12-01

    Revisions to the processes for training and certifying supervisors continue to be debated within the Association for Clinical Pastoral Education (ACPE). In 2012 Ragsdale and colleagues published, "Mutually engaged supervisory processes," a qualitative research study utilizing grounded theory based on interviews with 19 recently certified Associate CPE Supervisors, of nine components that facilitate the development of CPE supervisory education students. In this article we critically engage this theory and the research upon which it is based. We also reflect on three issues highlighted by the theory: personal transformation in CPE supervisory education, how CPE supervisory education students develop theoretical foundations for their work, and engaging multicultural issues in supervisory education. We conclude that this theory offers ACPE the possibility of using research to guide future modifications to its practice of Supervisory education. © 2014 Journal of Pastoral Care Publications Inc.

  19. Comparison of media for enumeration of Clostridium perfringens from foods

    NARCIS (Netherlands)

    Jong, A.E.I. de; Eijhusen, G.P.; Brouwer-Post, E.J.F.; Grand, M.; Johansson, T.; Kärkkäinen, T.; Marugg, J.; Veld, P.H. in 't; Warmerdam, F.H.M.; Wörner, G.; Zicavo, A.; Rombouts, F.M.; Beumer, R.R.

    2003-01-01

    Many media have been developed to enumerate Clostridium perfringens from foods. In this study, six media [iron sulfite (IS) agar, tryptose sulfite cycloserine (TSC) agar, Shahidi Ferguson perfringens (SFP) agar, sulfite cycloserine azide (SCA), differential clostridial agar (DCA), and oleandomycin

  20. Basis of Virulence in Enterotoxin-Mediated Staphylococcal Food Poisoning

    Directory of Open Access Journals (Sweden)

    Emilie L. Fisher

    2018-03-01

    Full Text Available The Staphylococcus aureus enterotoxins are a superfamily of secreted virulence factors that share structural and functional similarities and possess potent superantigenic activity causing disruptions in adaptive immunity. The enterotoxins can be separated into two groups; the classical (SEA-SEE and the newer (SEG-SElY and counting enterotoxin groups. Many members from both these groups contribute to the pathogenesis of several serious human diseases, including toxic shock syndrome, pneumonia, and sepsis-related infections. Additionally, many members demonstrate emetic activity and are frequently responsible for food poisoning outbreaks. Due to their robust tolerance to denaturing, the enterotoxins retain activity in food contaminated previously with S. aureus. The genes encoding the enterotoxins are found mostly on a variety of different mobile genetic elements. Therefore, the presence of enterotoxins can vary widely among different S. aureus isolates. Additionally, the enterotoxins are regulated by multiple, and often overlapping, regulatory pathways, which are influenced by environmental factors. In this review, we also will focus on the newer enterotoxins (SEG-SElY, which matter for the role of S. aureus as an enteropathogen, and summarize our current knowledge on their prevalence in recent food poisoning outbreaks. Finally, we will review the current literature regarding the key elements that govern the complex regulation of enterotoxins, the molecular mechanisms underlying their enterotoxigenic, superantigenic, and immunomodulatory functions, and discuss how these activities may collectively contribute to the overall manifestation of staphylococcal food poisoning.

  1. Effect of cooling on Clostridium perfringens in pea soup

    NARCIS (Netherlands)

    Jong, de A.E.I.; Rombouts, F.M.; Beumer, R.R.

    2004-01-01

    Foods associated with Clostridium perfringens outbreaks are usually abused after cooking. Because of their short generation times, C. perfringens spores and cells can grow out to high levels during improper cooling. Therefore, the potential of C. perfringens to multiply in Dutch pea soup during

  2. IoT-B&B: Edge-Based NFV for IoT Devices with CPE Crowdsourcing

    Directory of Open Access Journals (Sweden)

    He Zhu

    2018-01-01

    Full Text Available For embracing the ubiquitous Internet-of-Things (IoT devices, edge computing and Network Function Virtualization (NFV have been enabled in branch offices and homes in the form of virtual Customer-Premises Equipment (vCPE. A Service Provider (SP deploys vCPE instances as Virtual Network Functions (VNFs on top of generic physical Customer-Premises Equipment (pCPE to ease administration. Upon a usage surge of IoT devices at a certain part of the network, vCPU, memory, and other resource limitations of a single pCPE node make it difficult to add new services handling the high demand. In this paper, we present IoT-B&B, a novel architecture featuring resource sharing of pCPE nodes. When a pCPE node has sharable resources available, the SP will utilize its free resources as a “bed-and-breakfast” place to deploy vCPE instances in need. A placement algorithm is also presented to assign vCPE instances to a cost-efficient pCPE node. By keeping vCPE instances at the network edge, their costs of hosting are reduced. Meanwhile, the transmission latencies are maintained at acceptable levels for processing real-time data burst from IoT devices. The traffic load to the remote, centralized cloud can be substantially reduced.

  3. Genome-Wide Transcriptional Profiling of Clostridium perfringens SM101 during Sporulation Extends the Core of Putative Sporulation Genes and Genes Determining Spore Properties and Germination Characteristics.

    Science.gov (United States)

    Xiao, Yinghua; van Hijum, Sacha A F T; Abee, Tjakko; Wells-Bennik, Marjon H J

    2015-01-01

    The formation of bacterial spores is a highly regulated process and the ultimate properties of the spores are determined during sporulation and subsequent maturation. A wide variety of genes that are expressed during sporulation determine spore properties such as resistance to heat and other adverse environmental conditions, dormancy and germination responses. In this study we characterized the sporulation phases of C. perfringens enterotoxic strain SM101 based on morphological characteristics, biomass accumulation (OD600), the total viable counts of cells plus spores, the viable count of heat resistant spores alone, the pH of the supernatant, enterotoxin production and dipicolinic acid accumulation. Subsequently, whole-genome expression profiling during key phases of the sporulation process was performed using DNA microarrays, and genes were clustered based on their time-course expression profiles during sporulation. The majority of previously characterized C. perfringens germination genes showed upregulated expression profiles in time during sporulation and belonged to two main clusters of genes. These clusters with up-regulated genes contained a large number of C. perfringens genes which are homologs of Bacillus genes with roles in sporulation and germination; this study therefore suggests that those homologs are functional in C. perfringens. A comprehensive homology search revealed that approximately half of the upregulated genes in the two clusters are conserved within a broad range of sporeforming Firmicutes. Another 30% of upregulated genes in the two clusters were found only in Clostridium species, while the remaining 20% appeared to be specific for C. perfringens. These newly identified genes may add to the repertoire of genes with roles in sporulation and determining spore properties including germination behavior. Their exact roles remain to be elucidated in future studies.

  4. A novel Hsp70 inhibitor prevents cell intoxication with the actin ADP-ribosylating Clostridium perfringens iota toxin

    Science.gov (United States)

    Ernst, Katharina; Liebscher, Markus; Mathea, Sebastian; Granzhan, Anton; Schmid, Johannes; Popoff, Michel R.; Ihmels, Heiko; Barth, Holger; Schiene-Fischer, Cordelia

    2016-01-01

    Hsp70 family proteins are folding helper proteins involved in a wide variety of cellular pathways. Members of this family interact with key factors in signal transduction, transcription, cell-cycle control, and stress response. Here, we developed the first Hsp70 low molecular weight inhibitor specifically targeting the peptide binding site of human Hsp70. After demonstrating that the inhibitor modulates the Hsp70 function in the cell, we used the inhibitor to show for the first time that the stress-inducible chaperone Hsp70 functions as molecular component for entry of a bacterial protein toxin into mammalian cells. Pharmacological inhibition of Hsp70 protected cells from intoxication with the binary actin ADP-ribosylating iota toxin from Clostridium perfringens, the prototype of a family of enterotoxins from pathogenic Clostridia and inhibited translocation of its enzyme component across cell membranes into the cytosol. This finding offers a starting point for novel therapeutic strategies against certain bacterial toxins. PMID:26839186

  5. Clostridium perfringens isolate typing by multiplex PCR

    Directory of Open Access Journals (Sweden)

    MR Ahsani

    2010-01-01

    Full Text Available Clostridium perfringens is an important pathogen that provokes numerous different diseases. This bacterium is classified into five different types, each of which capable of causing a different disease. There are various methods for the bacterial identification, many are labor-intensive, time-consuming, expensive and also present low sensitivity and specificity. The aim of this research was to identify the different types of C. perfringens using PCR molecular method. In this study, 130 sheep-dung samples were randomly collected from areas around the city of Kerman, southeastern Iran. After processing and culturing of samples, the produced colonies were morphologically studied, gram stain test was also carried out and the genera of these bacteria were identified through biochemical tests. DNA extracted from isolated bacteria for genotyping was tested by multiplex PCR with specific primers. Based on length of synthesized fragments by PCR, toxin types and bacterial strains were detected. C. perfringens isolated types were divided as follows: 17.39% type A, 21.74% type B, 34.78% type C and 26.09% type D. It should be emphasized that, up to the present moment, C. perfringens type A has not been reported in Iran.

  6. CLOSTRIDIUM PERFRINGENS IN MEAT AND MEAT PRODUCTS.

    Science.gov (United States)

    HALL, H E; ANGELOTTI, R

    1965-05-01

    A total of 262 specimens of meat and meat dishes were examined for the presence of Clostridium perfringens. Of this total, 161 were raw, unprocessed beef, veal, lamb, pork, or chicken; 101 were processed meats and meat dishes. C. perfringens was isolated from 113 (43.1%) of these specimens. The highest percentage of contamination (82%) was found in veal cuts, and the lowest (4.7%) in sliced sandwich meats and spreads. Only 2 of the 113 isolates were shown to produce heat-resistant spores, which indicates a very low incidence (0.8%) of contamination. These findings indicate that outbreaks of C. perfringens food-borne disease in the Cincinnati area are caused principally by the contamination of the food with vegetative cells or spores of the organism after cooking. Studies of the effects of various holding temperatures on the growth of C. perfringens indicated that, in the range of 5 to 15 C, no multiplication would occur, but that viable cells would still be present at the end of a 5-day holding period. Extremely rapid growth occurred at temperatures around 45 C, and complete inhibition of growth was accomplished between 49 and 52 C.

  7. La CPE-Can forge des liens et place les étudiants au premier rang ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Canada (CPE-Can) :Dre Margot ParkesDepartment of Family Practice, University of British Columbia, CanadaDre Johanne Saint-CharlesCentre de recherche interdisciplinaire sur la biologie, la santé, la société et ...

  8. Cationic polymers in water treatment: Part 2: Filterability of CPE-formed suspension

    Czech Academy of Sciences Publication Activity Database

    Polášek, P.; Mutl, Silvestr

    2002-01-01

    Roč. 28, č. 1 (2002), s. 83-88 ISSN 0378-4738 R&D Projects: GA AV ČR KSK2067107 Institutional research plan: CEZ:AV0Z2060917 Keywords : cationic polymers * water treatment * filterability of CPE-formed suspension Subject RIV: BK - Fluid Dynamics Impact factor: 0.481, year: 2002

  9. Reduction of Aspergillus niger Virulence in Apple Fruits by Deletion of the Catalase Gene cpeB.

    Science.gov (United States)

    Zhang, Meng-Ke; Tang, Jun; Huang, Zhong-Qin; Hu, Kang-Di; Li, Yan-Hong; Han, Zhuo; Chen, Xiao-Yan; Hu, Lan-Ying; Yao, Gai-Fang; Zhang, Hua

    2018-05-30

    Aspergillus niger, a common saprophytic fungus, causes rot in many fruits. We studied the role of a putative catalase-peroxidase-encoding gene, cpeB, in oxidative stress and virulence in fruit. The cpeB gene was deleted in A. niger by homologous recombination, and the Δ cpeB mutant showed decreased CAT activity compared with that of the wild type. The cpeB gene deletion caused increased sensitivity to H 2 O 2 stress, and spore germination was significantly reduced; in addition, the reactive-oxygen-species (ROS) metabolites superoxide anions (·O 2 - ), hydrogen peroxide (H 2 O 2 ), and malondialdehyde (MDA) accumulated in the Δ cpeB mutant during H 2 O 2 stress. Furthermore, ROS metabolism in A. niger infected apples was determined, and our results showed that the Δ cpeB mutant induced an attenuated response in apple fruit during the fruit-pathogen interaction; the cpeB gene deletion significantly reduced the development of lesions, suggesting that the cpeB gene in A. niger is essential for full virulence in apples.

  10. Audit of the management of patients at high risk of carbapenemase-producing enterobacteriaceae (CPE): Are we ready?

    Science.gov (United States)

    Ratnayake, Lasantha; Harris, Amy; Ko, Doreen; Hawtin, Linda

    2017-11-01

    Incidence of carbapenemase-producing enterobacteriaceae (CPE) in the UK is increasing. In 2013, Public Health England (PHE) published a toolkit to control spread of CPE within healthcare settings. To assess compliance to hospital CPE policy (adapted from PHE) in the identification, isolation and screening of suspected CPE patients. Admission booklets of 150 patients were evaluated to see whether the relevant section had been completed to identify high-risk CPE patients. Where necessary, patients were interviewed or their GPs were contacted to assess their CPE risk. Additionally, 28 patients screened for CPE were audited to assess compliance to screening and isolation. Only 23 patients out of 147 (15.6%) were risk assessed on admission. Risk status of 27 (18.4%) patients could not be assessed due to lack of data. Fifteen patients out of 28 (54%) screened for CPE were identified and isolated on admission. Ten out of 19 patients (53%) had three screens 48 h apart. This audit highlights difficulties in screening based on individual risk factors as the majority of patients were not screened on admission and documentation on isolation and screening was poor. More needs to be done to raise awareness of the requirements for routine assessment, isolation and screening.

  11. A Quantitative Electrochemiluminescence Assay for Clostridium perfringens alpha toxin

    National Research Council Canada - National Science Library

    Merrill, Gerald A; Rivera, Victor R; Neal, Dwayne D; Young, Charles; Poli, Mark A

    2006-01-01

    .... Biotinylated antibodies to C. perfringens alpha toxin bound to streptavidin paramagnetic beads specifically immunoadsorbed soluble sample alpha toxin which subsequently selectively immunoadsorbed ruthenium (Ru...

  12. Production of staphylococcal enterotoxin A in cream-filled cake.

    Science.gov (United States)

    Anunciaçao, L L; Linardi, W R; do Carmo, L S; Bergdoll, M S

    1995-07-01

    Cakes were baked with normal ingredients and filled with cream, inoculated with different size enterotoxigenic-staphylococcal inocula. Samples of the cakes were incubated at room temperature and put in the refrigerator. Samples of cake and filling were taken at different times and analyzed for staphylococcal count and presence of enterotoxin. The smaller the inoculum, the longer the time required for sufficient growth (10(6)) to occur for production of detectable enterotoxin. Enterotoxin added to the cake dough before baking (210 degrees C, 45 min) did not survive the baking. The presence of enterotoxin in the contaminated cream filling indicated this as the cause of staphylococcal food poisoning from cream-filled cakes. Refrigeration of the cakes prevented the growth of the staphylococci.

  13. Antimicrobial susceptibility pattern of polymyxin b, tigecycline and fosfomycin against carbapenamase producing enterobacteriaceae (cpe)

    International Nuclear Information System (INIS)

    Abid, M.; Bhatti, A.; Malik, S.; Hussain, A.; Khan, I.U.

    2017-01-01

    To determine, the susceptibility pattern of carbapenamase producing enterobacteriaceae (CPE) against polymyxinB, tigecycline and fosfomycin. Study Design: Descriptive cross sectional. Place and Duration of Study: The study was carried out in the Department of Microbiology PNS Shifa Karachi, from 26 Sep 2013 to 25 Mar 2014. Material and Methods: All specimens were inoculated on blood and macConkey agar, incubated aerobically at 35 degree C - 37 degree C for 18 to 24 hours. After identification of gram negative rods by colony morphology, Gram's staining and biochemical reactions, these were screened for Carbapenems resistance with imipenem and meropenem 10 mu g discs along with routine first and second line antibiotics by Kirby-Bauer disc diffusion technique according to Clinical Laboratory Standard Institute (CLSI) guide lines. All isolated CPE were saved and then inoculated on Mueller-Hinton agar (MHA). Antimicrobial susceptibility against polymyxin B, Tigecycline and Fosfomycin was done by Kirby-Bauer disc diffusion method using disc polymyxin B 300 units, Tigecycline 15mu g and Fosfomycin 200 mu g. Zone diameters greater than 24 mm were taken as sensitive for Tigecycline 15 mu g, 16mm for Fosfomycin 200 mu g and 12 mm for polymyxin B 300 units. Results: Clinical specimens of 171 patients who fulfilled the inclusion criteria were included in our study. Mean +- SD of age was 42.02 +- 22.367 with C.I (38.65 - 45.40). Out of 171 patients 110 (64%) were male and 61 (36%) were female. In vitro susceptibility results revealed that all the 171 (100%) CPE isolates susceptible to PolymyxinB, while susceptibility against Fosfomycin and Tigecycline was 132 (77%) and 49 (29%) respectively. Conclusion: CPE were found to be 100% susceptible to polymyxinB, while for Fosfomycin and Tigecycline susceptibility was 77% and 29% respectively. (author)

  14. Perfringolysin O: The Underrated Clostridium perfringens Toxin?

    Science.gov (United States)

    Verherstraeten, Stefanie; Goossens, Evy; Valgaeren, Bonnie; Pardon, Bart; Timbermont, Leen; Haesebrouck, Freddy; Ducatelle, Richard; Deprez, Piet; Wade, Kristin R; Tweten, Rodney; Van Immerseel, Filip

    2015-05-14

    The anaerobic bacterium Clostridium perfringens expresses multiple toxins that promote disease development in both humans and animals. One such toxin is perfringolysin O (PFO, classically referred to as θ toxin), a pore-forming cholesterol-dependent cytolysin (CDC). PFO is secreted as a water-soluble monomer that recognizes and binds membranes via cholesterol. Membrane-bound monomers undergo structural changes that culminate in the formation of an oligomerized prepore complex on the membrane surface. The prepore then undergoes conversion into the bilayer-spanning pore measuring approximately 250-300 Å in diameter. PFO is expressed in nearly all identified C. perfringens strains and harbors interesting traits that suggest a potential undefined role for PFO in disease development. Research has demonstrated a role for PFO in gas gangrene progression and bovine necrohemorrhagic enteritis, but there is limited data available to determine if PFO also functions in additional disease presentations caused by C. perfringens. This review summarizes the known structural and functional characteristics of PFO, while highlighting recent insights into the potential contributions of PFO to disease pathogenesis.

  15. Perfringolysin O: The Underrated Clostridium perfringens Toxin?

    Directory of Open Access Journals (Sweden)

    Stefanie Verherstraeten

    2015-05-01

    Full Text Available The anaerobic bacterium Clostridium perfringens expresses multiple toxins that promote disease development in both humans and animals. One such toxin is perfringolysin O (PFO, classically referred to as θ toxin, a pore-forming cholesterol-dependent cytolysin (CDC. PFO is secreted as a water-soluble monomer that recognizes and binds membranes via cholesterol. Membrane-bound monomers undergo structural changes that culminate in the formation of an oligomerized prepore complex on the membrane surface. The prepore then undergoes conversion into the bilayer-spanning pore measuring approximately 250–300 Å in diameter. PFO is expressed in nearly all identified C. perfringens strains and harbors interesting traits that suggest a potential undefined role for PFO in disease development. Research has demonstrated a role for PFO in gas gangrene progression and bovine necrohemorrhagic enteritis, but there is limited data available to determine if PFO also functions in additional disease presentations caused by C. perfringens. This review summarizes the known structural and functional characteristics of PFO, while highlighting recent insights into the potential contributions of PFO to disease pathogenesis.

  16. Molecular typing and antimicrobial susceptibility of Clostridium perfringens from broiler chickens.

    Science.gov (United States)

    Gharaibeh, Saad; Al Rifai, Rami; Al-Majali, Ahmad

    2010-12-01

    Clostridium perfringens (Cp) causes necrotic enteritis disease in commercial poultry. Antimicrobials are used to control and treat this disease and sometimes clinical outbreaks do not respond well to certain treatments. This study was designed to isolate Cp from clinical cases, type these isolates by multiplex PCR, and determine their antimicrobial susceptibility by micro-dilution method. A total of 67 Cp isolates were obtained from 155 broiler chicken flocks. All isolates were classified as type A and non-enterotoxin producers. Lincomycin, erythromycins, and tilmicosin showed very high minimal inhibitory concentration (MIC) 50 of ≥256 μg/ml. However, tylosin, amoxicillin, ampicillin, penicillin, florfenicol, danofloxacin, enrofloxacin, chlortetracycline, doxycycline, and oxytetracycline had variable MIC₅₀ of 64, 0.5, 1, 1, 8, 4, 8, 4, 8, 0.5 μg/ml, respectively. It is recommended that Cp infections in Jordan be treated with either penicillins or tetracyclines especially amoxicillin and oxytetracycline. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Schiff Base modified on CPE electrode and PCB gold electrode for selective determination of silver ion

    Science.gov (United States)

    Leepheng, Piyawan; Suramitr, Songwut; Phromyothin, Darinee

    2017-09-01

    The schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The schiff base modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The electrochemical study was reported by cyclic voltammetry method and impedance spectroscopy using modified electrode as working electrode, platinum wire and Ag/AgCl as counter electrode and reference electrode, respectively. The modified electrodes have suitable detection for Ag+. The determination of silver ions using the modified electrodes depended linearly on Ag+ concentration in the range 1×10-10 M to 1×10-7 M, with cyclic voltammetry sensitivity were 2.51×108 μAM-1 and 1.88×108 μAM-1 for PCB gold electrode and CPE electrode, respectively, limits of detection were 5.33×10-9 M and 1.99×10-8 M for PCB gold electrode and CPE electrode, respectively. The modified electrodes have high accuracy, inexpensive and can applied to detection Ag+ in real samples.

  18. A toxic approach to beta2-toxigenic Clostridium perfringens

    NARCIS (Netherlands)

    Allaart, J.G.

    2013-01-01

    Clostridium perfringens is one of the most important causes of intestinal disease in animals and humans. Its virulence is attributed to the several toxins it can produce, including the beta2 toxin encoded by cpb2. In this thesis we studied the role of the beta2 toxin produced by C. perfringens in

  19. Voltammetric Determination of Anethole on La2O3/CPE and BDDE

    Directory of Open Access Journals (Sweden)

    Mateusz Kowalcze

    2018-01-01

    Full Text Available In this work, DPV determination of anethole was presented using various carbon, two-diameter (1.5 and 3 mm electrodes, that is, BDD, GC, CP, and CP doped by La2O3 and CeO2 nanoparticles. La2O3/CPE to our best knowledge was proposed first time. Cyclic voltammograms confirmed totally irreversible electrode electrooxidation process, controlled by diffusion, in which two electrons take part. The most satisfactory sensitivity 0.885 ± 0.016 µA/mg L−1 in 0.1 mol L−1 acetate buffer was obtained for La2O3/CPE with the correlation coefficient r of 0.9993, while for BDDE it was 0.135 ± 0.003 µA/mg L−1 with r of 0.9990. The lowest detection limit of 0.004 mg L−1 was reached on La2O3/CPE (3 mm, what may be compared with the most sensitive conjugate methods, but in the proposed approach, no sample preparation and analyte separation was needed. Anethole was successfully determined in specially prepared ethanol extracts of herbal mixtures of various compositions, which imitated real products. The proposed procedure was verified in analysis of commercial products, that is, anise essential oil, which contains a large concentration of anethole, and in alcohol drinks like Metaxa, Ouzo, and Rakija, in which the considered analyte occurs on trace levels. Structure and properties of the considered nanopowders and graphite pastes were investigated by EDX, SEM, and EIS.

  20. Production of enterotoxin by Salmonella exposed to X rays

    International Nuclear Information System (INIS)

    Szulc, M.; Pliszka, A.; Peconek, J.

    1982-01-01

    The influence of irradiation on enterotoxin production by Salmonella enteritidis and S. typhimurium was evaluated using skin test elaborated by Tschaepe and others. The strains examined appeared to be equally sensitive to X rays. A dose of 100 Gy decreased the number of bacterial cells at approx. 10 D 10 and 200 Gy at 2-3 D 10 . Irradiation with 100 and 200 Gy of X rays did not influence enterotoxin production by microorganisms which were resistant to the process of irradiation. (author)

  1. Prevalence of enterotoxigenic Bacillus Cereus and Its enterotoxins ...

    African Journals Online (AJOL)

    Objectives: To determine the prevalence of enterotoxigenic Bacillus cereus (B. cereus) and enterotoxins in milk and milk products. Design: A random sampling of milk products was carried out. Setting: Market milk and milk products were collected from retail shops in Nairobi and analysed for contamination with ...

  2. Prevalence, antibiotic-resistance properties and enterotoxin gene ...

    African Journals Online (AJOL)

    Prevalence, antibiotic-resistance properties and enterotoxin gene profile of Bacillus cereus strains isolated from milk-based baby foods. ... Conclusion: Considerable prevalence of resistant and toxigenic B. cereus and high consumption of milk-based infant foods in Iran, represent an important public health issue which ...

  3. Construction of PVX virus-expression vector to express enterotoxin ...

    African Journals Online (AJOL)

    Potato X potyvirus (PVX)-based vector has been comprehensively applied in transient expression system. In order to produce the heterologous proteins more quickly and stably, the ClaI and NotI enzyme sites were introduced into the Enterotoxin fusion gene LTB-ST by polymerase chain reaction (PCR) and the LTB-ST ...

  4. Reproducible Infection Model for Clostridium perfringens in Broiler Chickens

    DEFF Research Database (Denmark)

    Pedersen, Karl; Friis-Holm, Lotte Bjerrum; Heuer, Ole Eske

    2008-01-01

    , 18, 20, and 24 ( Experiment 2). There was no mortality in any of the groups; however, chickens in the groups receiving both coccidial vaccine and C. perfringens developed the subclinical form of necrotic enteritis, demonstrated by focal necroses in the small intestine, whereas chickens in control...... groups or groups receiving only coccidial vaccine or only C. perfringens cultures developed no necroses. The results underline the importance of predisposing factors in the development of necrotic enteritis....

  5. Critical Point Facility (CPE) Group in the Spacelab Payload Operations Control Center (SL POCC)

    Science.gov (United States)

    1992-01-01

    The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Critical Point Facility (CPE) group in the SL POCC during STS-42, IML-1 mission.

  6. Growth of Clostridium perfringens during cooling of refried beans.

    Science.gov (United States)

    Cevallos-Cevallos, Juan M; Akins, E Deann; Friedrich, Loretta M; Danyluk, Michelle D; Simonne, Amarat H

    2012-10-01

    Outbreaks of Clostridium perfringens have been associated with dishes containing refried beans from food service establishments. However, growth of C. perfringens in refried beans has not been investigated, and predictive models have not been validated in this food matrix. We investigated the growth of C. perfringens during the cooling of refried beans. Refried beans (pinto and black, with and without salt added) were inoculated with 3 log CFU/g C. perfringens spores and incubated isothermally at 12, 23, 30, 35, 40, 45, and 50°C. The levels of C. perfringens were monitored 3, 5, 8, and 10 h after inoculation, and then fitted to the Baranyi primary model and the Rosso secondary model prior to solving the Baranyi differential equation. The final model was validated by dynamic cooling experiments carried out in stockpots, thus mimicking the worst possible food service conditions. All refried beans samples supported the growth of C. perfringens, and all models fit the data with pseudo-R(2) values of 0.95 or greater and mean square errors of 0.3 or lower. The estimated maximum specific growth rates were generally higher in pinto beans, with or without salt added (2.64 and 1.95 h(-1), respectively), when compared with black beans, with or without salt added (1.78 and 1.61 h(-1), respectively). After 10 h of incubation, maximum populations of C. perfringens were significantly higher in samples with no salt added (7.9 log CFU/g for both pinto and black beans) than in samples with salt added (7.3 and 7.2 log CFU/g for pinto and black beans, respectively). The dynamic model predicted the growth of C. perfringens during cooling, with an average root mean squared error of 0.44. The use of large stockpots to cool refried beans led to an observed 1.2-log increase (1.5-log increase predicted by model) in levels of C. perfringens during cooling. The use of shallower pans for cooling is recommended, because they cool faster, therefore limiting the growth of C. perfringens.

  7. Use of single-enzyme amplified fragment length polymorphism for typing Clostridium perfringens isolated from diarrheic piglets Uso do polimorfismo do comprimento de fragmentos amplificados para tipagem de Clostridium perfringens isolados de suínos com diarréia

    Directory of Open Access Journals (Sweden)

    Luciane Tieko Shinya

    2006-09-01

    Full Text Available Clostridium perfringens is an important pathogen in human and veterinary medicine. In swine, the agent is responsible for necrotic enteritis and enterotoxemia characterized by diarrhea, weight loss, delayed development and, in some cases, death. In the present study amplified fragment length polymorphism analyses (AFLP was used to characterize 54 C. perfringens strains isolated from swine presenting diarrhea. Analysis of the results showed 29 distinct profiles with discriminatory index equal to 0.97. Partial correlation between the origin of the isolates and groups was drawn, and correlation was possible in only 18.5% of the samples. Characterization of the strains in biotypes (A, B, C, D and E, production of beta-2 toxin and enterotoxin were performed by means of the polymerase chain reaction (PCR. Biotypes A, C and D were observed among the strains analyzed. All samples were positive for presence of the gene encoding beta-2 toxin and negative for the gene encoding enterotoxin. AFLP have shown to be a simple, fast, low cost method with high discriminative power and good reproducibility, presenting a great potential in epidemiological studies involving C. perfringens strains of animal origin.Clostridium perfringens é um importante agente infeccioso em medicina veterinária e humana. Em suínos, o agente é responsável pela enterite necrótica e enterotoxemia, caracterizadas por diarréia, perda de peso, atraso no desenvolvimento e morte. No presente estudo foi utilizado o polimorfismo do comprimento de fragmentos amplificados (AFLP, para caracterizar 54 isolados de C. perfringens obtidos de suínos com diarréia. A análise dos resultados do AFLP demonstrou 29 perfis distintos com índice discriminatório igual a 0,97. A correlação entre a origem dos isolados e os agrupamentos obtidos foi parcial, sendo apenas possível a correlação total de 18,5% das amostras estudadas. A caracterização das cepas em biotipos (A, B, C, D e E, produ

  8. Evaluation of an alternative extraction procedure for enterotoxin determination in dairy products.

    Science.gov (United States)

    Meyrand, A; Atrache, V; Bavai, C; Montet, M P; Vernozy-Rozand, C

    1999-06-01

    A concentration protocol based on trichloroacetic acid precipitation was evaluated and compared with the reference method using dialysis concentration. Different quantities of purified staphylococcal enterotoxins were added to pasteurized Camembert-type cheeses. Detection of enterotoxins in these cheeses was performed using an automated detection system. Raw goat milk Camembert-type cheeses involved in a staphylococcal food poisoning were also tested. Both enterotoxin extraction methods allowed detection of the lowest enterotoxin concentration level used in this study (0.5 ng g-1). Compared with the dialysis concentration method, TCA precipitation of staphylococcal enterotoxins was 'user-friendly' and less time-consuming. These results suggest that TCA precipitation is a rapid (1 h), simple and reliable method of extracting enterotoxin from food which gives excellent recovery from dairy products.

  9. Analysis of plasmid profiling as a method for rapid differentiation of food-associated Clostridium perfringens strains.

    Science.gov (United States)

    Jones, M K; Iwanejko, L A; Longden, M S

    1989-09-01

    Plasmid analysis of over 120 strains of Clostridium perfringens, isolated during food-poisoning incidents and from animal carcasses and food constituents with no association with food poisoning, showed the potential of plasmid profiling as a means of differentiating epidemiologically related strains. On average 65% of freshly isolated strains contained one or more plasmids which could be used in the analysis. Comparison of profiles of strains from unrelated sources or unrelated strains from the same source showed a particularly wide variety of plasmid profiles. Thus the possibility that epidemiologically-unrelated strains might possess similar profiles appears to be very low in this organism. Analysis of serologically-related strains from the same source revealed similar plasmid profiles in all the plasmid-bearing strains examined. A high proportion (71%) of fresh and well-characterized food-poisoning strains possessed plasmids of 6.2 kb in size (compared with 19% of non-food-poisoning strains). The possible role of these plasmids is discussed, since the structural gene encoding the enterotoxin type A was not present on any of the plasmids in the food-poisoning strains tested.

  10. Monkey Feeding Assay for Testing Emetic Activity of Staphylococcal Enterotoxin.

    Science.gov (United States)

    Seo, Keun Seok

    2016-01-01

    Staphylococcal enterotoxins (SEs) are unique bacterial toxins that cause gastrointestinal toxicity as well as superantigenic activity. Since systemic administration of SEs induces superantigenic activity leading to toxic shock syndrome that may mimic enterotoxic activity of SEs such as vomiting and diarrhea, oral administration of SEs in the monkey feeding assay is considered as a standard method to evaluate emetic activity of SEs. This chapter summarizes and discusses practical considerations of the monkey feeding assay used in studies characterizing classical and newly identified SEs.

  11. An optimized work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs.

    Science.gov (United States)

    O'Connor, C; Kiernan, M G; Finnegan, C; O'Hara, M; Power, L; O'Connell, N H; Dunne, C P

    2017-05-04

    Rapid detection of patients with carbapenemase-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilizing existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n = 10) and anonymized community stool specimens (n = 200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took method of CPE screening; average time-to-diagnosis of 48/72 h. Utilizing this CPE work-flow would allow a 'same-day' result. Antimicrobial susceptibility testing results, as is current practice, would remain a 'next-day' result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing.

  12. Hazard analysis of Clostridium perfringens in the Skylab Food System

    Science.gov (United States)

    Bourland, C. T.; Huber, C. S.; Kiser, P. R.; Heidelbaugh, N. D.; Rowley, D. B.

    1974-01-01

    The Skylab Food System presented unique microbiological problems because food was warmed in null-gravity and because the heat source was limited to 69.4 C (to prevent boiling in null-gravity). For these reasons, the foods were manufactured using critical control point techniques of quality control coupled with appropriate hazard analyses. One of these hazard analyses evaluated the threat from Clostridium perfringens. Samples of food were inoculated with C. perfringens and incubated for 2 h at temperatures ranging from 25 to 55 C. Generation times were determined for the foods at various temperatures. Results of these tests were evaluated taking into consideration: food-borne disease epidemiology, the Skylab food manufacturing procedures, and the performance requirements of the Skylab Food System. Based on this hazard analysis, a limit for C. perfringens of 100/g was established for Skylab foods.

  13. The prevalence of methicillin-resistant Staph. aureus strains producing enterotoxin A and B

    Directory of Open Access Journals (Sweden)

    Safiyeh Abbasi

    2016-02-01

    Full Text Available Background: Staphylococcus aureus is a gram positive coccus which is able to cause different kinds of infection in certain condition. The function of this bacteria is to provide the conditions for the invasion of it to the host with the secretion of different sorts of toxins such as Staphylococcus aureus enterotoxin, including important virulence factors that super antigens are all factors digestive inconvenience. Staphylococcus aureus enterotoxin-secreting toxins such conditions provides invasion of host genes. There are different types of SE, but type A enterotoxin (SEA and type B enterotoxin (SEB are the most important types. Therefore, in this study, the prevalence of Staphylococcus aureus toxin-producing enterotoxin genes (SEB, SEA in clinical strains isolated from patients in teaching hospitals of Shahrekord city, Iran, were studied. Methods: This cross-sectional and descriptive study, which was conducted from May 2014 to December 2014. A hundred and ten isolates of Staphylococcus aureus from patients collected over a period of 8 months and were first identified using standard biochemical methods and laboratory. Using standard methods and laboratory tests were identified and compared with the antibiotic oxacillin minimum inhibitory concentration were determined by broth micro dilution, and then they were assessed by polymerase chain reaction (PCR technique. Results: The results indicated that, 110 samples of dairy products infected by Staphylococcus aureus were detected. Two cases (1.8% of these infected samples were carrying both enterotoxin A and enterotoxin B genes. The frequencies of enterotoxin A genes were twenty-six cases (23/6% and The frequencies of enterotoxin B genes were two cases (1/8%, respectively. Conclusion: The detection of enterotoxin A and enterotoxin B genes, shows the most important role they have in bringing about superinfection. The detection of enterotoxin A and B genes, shows the most important role they have in

  14. Determination of arsenic species in rice samples using CPE and ETAAS.

    Science.gov (United States)

    Costa, Bruno Elias Dos Santos; Coelho, Nívia Maria Melo; Coelho, Luciana Melo

    2015-07-01

    A highly sensitive and selective procedure for the determination of arsenate and total arsenic in food by electrothermal atomic absorption spectrometry after cloud point extraction (ETAAS/CPE) was developed. The procedure is based on the formation of a complex of As(V) ions with molybdate in the presence of 50.0 mmol L(-1) sulfuric acid. The complex was extracted into the surfactant-rich phase of 0.06% (w/v) Triton X-114. The variables affecting the complex formation, extraction and phase separation were optimized using factorial designs. Under the optimal conditions, the calibration graph was linear in the range of 0.05-10.0 μg L(-1). The detection and quantification limits were 10 and 33 ng L(-1), respectively and the corresponding value for the relative standard deviation for 10 replicates was below 5%. Recovery values of between 90.8% and 113.1% were obtained for spiked samples. The accuracy of the method was evaluated by comparison with the results obtained for the analysis of a rice flour sample (certified material IRMM-804) and no significant difference at the 95% confidence level was observed. The method was successfully applied to the determination of As(V) and total arsenic in rice samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Modeling growth of Clostridium perfringens in pea soup during cooling

    NARCIS (Netherlands)

    Jong, de A.E.I.; Beumer, R.R.; Zwietering, M.H.

    2005-01-01

    Clostridium perfringens is a pathogen that mainly causes food poisoning outbreaks when large quantities of food are prepared. Therefore, a model was developed to predict the effect of different cooling procedures on the growth of this pathogen during cooling of food: Dutch pea soup. First, a growth

  16. Occurrence of Clostridium perfringens in sausages sold in Meknes ...

    African Journals Online (AJOL)

    In Morocco, the consumption of meat products has experienced a sharp increase in recent years despite the presence of pathogenic bacteria due to hygiene failure. The present study was designed to determine the prevalence of Clostridium perfringens in sausages sold in Meknes city (Morocco) and to study the different ...

  17. Experimental Clostridium perfringens type D enterotoxemia in goats.

    Science.gov (United States)

    Uzal, F A; Kelly, W R

    1998-03-01

    The effects of intraduodenal administration of Clostridium perfringens cultures and culture products in goats were evaluated to develop a reliable experimental model of enterotoxemia in this species. Five conventionally reared, 11-16-week-old Angora goat kids were dosed intraduodenally with whole cultures of C. perfringens type D; five similar animals were dosed with C. perfringens type D filtered culture supernatant; and a third group of five kids was dosed with C. perfringens type D washed cells. Two kids were used as controls and received sterile, nontoxic culture medium intraduodenally. All animals received starch solution into the abomasum. All five kids inoculated with whole culture and three of five dosed with culture supernatant and with washed cells developed central nervous system signs. Diarrhea was observed in two of five kids inoculated with whole culture, in all five of those dosed with culture supernatant, and in three of five of those that received washed cells. The most striking postmortem findings consisted of lung edema, necrotizing pseudomembranous colitis, and cerebral vasogenic edema. The protocol thus provided a reasonable model of naturally occurring enterotoxemia in goats, producing a range of clinical signs and postmortem changes similar to those observed in the natural disease.

  18. 9 CFR 113.455 - Clostridium Perfringens Type D Antitoxin.

    Science.gov (United States)

    2010-01-01

    ... Clostridium perfringens Type D. Each serial shall be tested as provided in this section. Any serial found... following words and terms shall mean: (i) International antitoxin unit. (I.U.) That quantity of Epsilon... 0.25 gram of sodium chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving...

  19. 9 CFR 113.454 - Clostridium Perfringens Type C Antitoxin.

    Science.gov (United States)

    2010-01-01

    ... Clostridium perfringens Type C. Each serial shall be tested as provided in this section. Any serial found... following words and terms shall mean: (i) International antitoxin unit. (I.U.) That quantity of Beta... chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving at 250 °F. for 25 minutes...

  20. Strategy to inactivate Clostridium perfringens spores in meat products.

    Science.gov (United States)

    Akhtar, Saeed; Paredes-Sabja, Daniel; Torres, J Antonio; Sarker, Mahfuzur R

    2009-05-01

    The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 degrees C, 10 min); spore germination at high temperatures (55, 60 or 65 degrees C); and inactivation of germinated spores with elevated temperatures (80 and 90 degrees C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 degrees C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 degrees C, 10 min), and germinated at temperatures lethal for vegetative cells (>or= 55 degrees C) when incubated for 60 min with a mixture of L-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (approximately 4 decimal reduction) in meat by elevated temperatures (80-90 degrees C for 20 min) required a long germination period (55 degrees C for 60 min). However, similar inactivation level was reached with shorter germination period (55 degrees C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 degrees C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 degrees C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 degrees C in about 20 min and further incubation at 55 degrees C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 degrees C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C

  1. Heat-Labile Enterotoxin: Beyond G M1 Binding

    Directory of Open Access Journals (Sweden)

    Benjamin Mudrak

    2010-06-01

    Full Text Available Enterotoxigenic Escherichia coli (ETEC is a significant source of morbidity and mortality worldwide. One major virulence factor released by ETEC is the heat-labile enterotoxin LT, which is structurally and functionally similar to cholera toxin. LT consists of five B subunits carrying a single catalytically active A subunit. LTB binds the monosialoganglioside GM1, the toxin’s host receptor, but interactions with A-type blood sugars and E. coli lipopolysaccharide have also been identified within the past decade. Here, we review the regulation, assembly, and binding properties of the LT B-subunit pentamer and discuss the possible roles of its numerous molecular interactions.

  2. Growth and enterotoxin production of Bacillus cereus in cow, goat, and sheep milk

    Directory of Open Access Journals (Sweden)

    Lenka Necidová

    2014-01-01

    Full Text Available The aim of this study was to compare Bacillus cereus growth rates and diarrhoeal enterotoxin production in raw and pasteurized goat, sheep, and cow milk in terms of storage conditions. Milk samples were inoculated with B. cereus (CCM 2010, which produces diarrhoeal enterotoxins. Enterotoxin production was tested by ELISA (Enzyme-Linked Immunosorbent Assay, and the count of B. cereus was determined by the plate method. With raw cow milk, B. cereus growth and enterotoxin production can be completely suppressed; in raw goat and sheep milk, enterotoxin was produced at 22 °C. In pasteurized cow, goat, and sheep milk, the B. cereus count increased under all storage conditions, with more rapid growth being observed at 15 °C (sheep milk and 22 °C (cow and goat milk. Enterotoxin presence was detected at 15 °C and 22 °C, and with pasteurized cow milk also at 8 °C. Our model experiments have determined that B. cereus multiplication and subsequent enterotoxin production depend on storage temperature and milk type.

  3. Calcium Montmorillonite-based dietary supplement attenuates Necrotic Enteritis induced by Eimeria maxima and Clostridium perfringens in broilers

    Science.gov (United States)

    We provide the first description of Dietary Supplement of sorbent minerals attenuates Necrotic Enteritis Induced by Eimeria maxima and Clostridium perfringens in Broilers. Necrotic enteritis (NE) is a poultry disease caused by Clostridium perfringens and characterized by severe intestinal necrosis....

  4. Recent Insights into Clostridium perfringens Beta-Toxin

    Directory of Open Access Journals (Sweden)

    Masahiro Nagahama

    2015-02-01

    Full Text Available Clostridium perfringens beta-toxin is a key mediator of necrotizing enterocolitis and enterotoxemia. It is a pore-forming toxin (PFT that exerts cytotoxic effect. Experimental investigation using piglet and rabbit intestinal loop models and a mouse infection model apparently showed that beta-toxin is the important pathogenic factor of the organisms. The toxin caused the swelling and disruption of HL-60 cells and formed a functional pore in the lipid raft microdomains of sensitive cells. These findings represent significant progress in the characterization of the toxin with knowledge on its biological features, mechanism of action and structure-function having been accumulated. Our aims here are to review the current progresses in our comprehension of the virulence of C. perfringens type C and the character, biological feature and structure-function of beta-toxin.

  5. Uterine Clostridium perfringens infection related to gynecologic malignancy.

    Science.gov (United States)

    Kremer, Kevin M; McDonald, Megan E; Goodheart, Michael J

    2017-11-01

    Uterine gas gangrene caused by Clostridium perfringens is a serious, often life-threatening infection that is rarely encountered in the practice of gynecologic oncology. However, the hypoxic nature of gynecologic cancers due to necrosis and/or prior radiation therapy creates a microenvironment optimal for proliferation of anaerobic bacteria such as the Clostridium species. Early recognition and aggressive treatment with IV antibiotics and surgical debridement remain the cornerstones of management in order to decrease morbidity and mortality. Here we present the case of a 52 year-old woman with a remote history of cervical cancer who was previously treated at our institution with primary chemotherapy and radiation and was then admitted decades later with Clostridium perfringens bacteremia and CT evidence of intrauterine abscess. The patient received a prolonged course of IV antibiotic therapy and subsequently underwent definitive surgical management with a total abdominal hysterectomy, bilateral salpingo-oophorectomy, small bowel resection with anastomosis for a utero-ileal fistula identified intraoperatively. Pathology from the uterine specimen demonstrated a primary poorly differentiated uterine adenocarcinoma. The patient recovered fully from her Clostridium perfringens infection and was discharged from the hospital shortly after surgical intervention.

  6. Pancreatitis caused by Clostridium perfringens infection with extensive retropneumoperitoneum

    International Nuclear Information System (INIS)

    Merchante, E.; Garcia, F. J.; Perez, H.; Marquez, J. L.

    2001-01-01

    We present a case of primary emphysematous pancreatitis caused by Clostridium perfringens infection (also Known as spontaneous pancreatic gas gangrene) in a 66-year-old man with diabetes and a history of recurrent pancreatitis. One notable feature is the absence of a focal distribution, which is seen on radiological studies to be accompanied by extensive retropneumoperitoneum, with dissemination of the gas toward the mesenteric root and pelvic extra peritoneal spaces. This wide diffusion is aided by the C. perfringens toxins and the pancreatic enzymes released, leading to a fulminate course, an elevated rate of early mortality among the cases reviewed. The early diagnosis of this disease is fundamental, enabling aggressive medical treatment and emergency surgery. Diabetes is a known risk factor for anaerobic infection, including C. perfringens, as in the case of emphysematous cholecystitis. A diseased pancreas or pancreatic duct facilitates the development of infections since it eliminates poorly the microorganisms that reach it from the duodenum. Gas gangrene secondary to necrosis-related super infection or pancreatic collections is uncommon, and spontaneous or primary cases are exceptionally are. (Author) 13 refs

  7. Sulfasalazine Attenuates Staphylococcal Enterotoxin B-Induced Immune Responses

    Directory of Open Access Journals (Sweden)

    Teresa Krakauer

    2015-02-01

    Full Text Available Staphylococcal enterotoxin B (SEB and related exotoxins are important virulence factors produced by Staphylococcus aureus as they cause human diseases such as food poisoning and toxic shock. These toxins bind directly to cells of the immune system resulting in hyperactivation of both T lymphocytes and monocytes/macrophages. The excessive release of proinflammatory cytokines from these cells mediates the toxic effects of SEB. This study examined the inhibitory activities of an anti-inflammatory drug, sulfasalazine, on SEB-stimulated human peripheral blood mononuclear cells (PBMC. Sulfasalazine dose-dependently inhibited tumor necrosis factor α, interleukin 1 (IL-1 β, IL-2, IL-6, interferon γ (IFNγ, and various chemotactic cytokines from SEB-stimulated human PBMC. Sulfasalazine also potently blocked SEB-induced T cell proliferation and NFκB activation. These results suggest that sulfasalazine might be useful in mitigating the toxic effects of SEB by blocking SEB-induced host inflammatory cascade and signaling pathways.

  8. The staphylococcal enterotoxin (SE) family: SEB and siblings.

    Science.gov (United States)

    Krakauer, Teresa; Stiles, Bradley G

    2013-11-15

    Staphylococcus aureus plays an important role in numerous human cases of food poisoning, soft tissue, and bone infections, as well as potentially lethal toxic shock. This common bacterium synthesizes various virulence factors that include staphylococcal enterotoxins (SEs). These protein toxins bind directly to major histocompatibility complex class II on antigen-presenting cells and specific Vβ regions of T-cell receptors, resulting in potentially life-threatening stimulation of the immune system. Picomolar concentrations of SEs ultimately elicit proinflammatory cytokines that can induce fever, hypotension, multi-organ failure, and lethal shock. Various in vitro and in vivo models have provided important tools for studying the biological effects of, as well as potential vaccines/therapeutics against, the SEs. This review succinctly presents known physical and biological properties of the SEs, including various intervention strategies. In particular, SEB will often be portrayed as per biodefense concerns dating back to the 1960s.

  9. Determination of trace amounts of Brown HT as a food dye by a CPE-scanometry method

    Directory of Open Access Journals (Sweden)

    A. Shokrollahi

    2017-01-01

    Full Text Available In this study, trace amounts of Brown HT were extracted, pre-concentrated and determined by cloud point extraction-scanometry (CPE-scanometry as a simple, fast and inexpensive method. The procedure is based on CPE of Brown HT from an aqueous solution, diluting the extracted surfactant-rich phase with ethanol to 500 μL, transferring the appropriate volume to Plexiglas® cells and scanning the cells. Then, the colour of each cell was analyzed by software written in visual basic (VB 6 into red, green and blue values. Effective parameters for the extraction efficiency, such as the pH of the system, the concentration of surfactant, the equilibration temperature and equilibration time, were investigated and optimized. Under optimal conditions, the calibration curve was linear in the range of 0.06–2.60 mg L−1. The detection limit of the proposed method was 0.04 mg L−1. In addition, the effects of some foreign species, including cations, anions and dyes, were investigated. The method was applied successfully for the determination of Brown HT in some water samples.

  10. Isolation and molecular characterization of Clostridium perfringens from healthy Merino lambs in Patagonia region, Argentina

    DEFF Research Database (Denmark)

    Mignaqui, A. C.; Marcellino, R. B.; Ronco, Troels

    2017-01-01

    The presence and molecular characterization of Clostridium perfringens in healthy Merino lambs over a six-month period was investigated in this study. Overall, a high prevalence of C. perfringens was detected, even in day-old lambs. Even though the majority of the isolates were characterized...

  11. 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.

  12. Tolerance of Clostridium perfringens biofilms to disinfectants commonly used in the food industry.

    Science.gov (United States)

    Charlebois, Audrey; Jacques, Mario; Boulianne, Martine; Archambault, Marie

    2017-04-01

    Clostridium perfringens is an opportunistic pathogen that can cause food poisoning in humans and various enterotoxemia in animal species. Recently, it was shown to form mono-species biofilms, a structured community of bacterial cells enclosed in a self-produced extracellular matrix. Biofilms have been associated with tolerance to antibiotics, disinfectants, and physical and environmental stresses. Very little is known about the tolerance of C. perfringens biofilm toward disinfectants. In the present study, susceptibilities of C. perfringens biofilms to five types of commonly used disinfectants on farms and in food processing environments were analysed. In this paper, we show that C. perfringens mono-species biofilms can protect the bacterial cells from the action of potassium monopersulfate, quaternary ammonium chloride, hydrogen peroxide and glutaraldehyde solutions. However, sodium hypochlorite solution was shown to be effective on C. perfringens biofilms. Our investigation of dual-species biofilms of C. perfringens with the addition of Staphylococcus aureus or Escherichia coli demonstrated that overall, the mono-species biofilm of C. perfringens was more tolerant to all disinfectants than the dual-species biofilms. For the anaerobic grown biofilms, the mono-species biofilm of C. perfringens was more tolerant to sodium hypochlorite and quaternary ammonium chloride than the dual-species biofilms of C. perfringens with S. aureus or E. coli. This study demonstrates that C. perfringens biofilm is an effective protection mechanism to disinfectants commonly used on farms and in food processing environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Truncating Homozygous Mutation of Carboxypeptidase E (CPE in a Morbidly Obese Female with Type 2 Diabetes Mellitus, Intellectual Disability and Hypogonadotrophic Hypogonadism.

    Directory of Open Access Journals (Sweden)

    Suzanne I M Alsters

    Full Text Available Carboxypeptidase E is a peptide processing enzyme, involved in cleaving numerous peptide precursors, including neuropeptides and hormones involved in appetite control and glucose metabolism. Exome sequencing of a morbidly obese female from a consanguineous family revealed homozygosity for a truncating mutation of the CPE gene (c.76_98del; p.E26RfsX68. Analysis detected no CPE expression in whole blood-derived RNA from the proband, consistent with nonsense-mediated decay. The morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotrophic hypogonadism seen in this individual recapitulates phenotypes in the previously described fat/fat and Cpe knockout mouse models, evidencing the importance of this peptide/hormone-processing enzyme in regulating body weight, metabolism, and brain and reproductive function in humans.

  14. Effect of Sodium Chloride and pH on Enterotoxin C Production

    Science.gov (United States)

    Genigeorgis, Constantin; Foda, Mohamed S.; Mantis, Antony; Sadler, Walter W.

    1971-01-01

    Growth and production of enterotoxin C by Staphylococcus aureus strain 137 in 3% + 3% protein hydrolysate powder N-Z Amine NAK broths with 0 to 12% NaCl and an initial pH of 4.00 to 9.83 were studied during an 8-day incubation period at 37 C. Growth was initiated at pH values as low as 4.00 and as high as 9.83 at 0% salt level as long as the inoculum contained at least 108 cells per ml. Rate of growth decreased as the NaCl concentration was increased gradually to 12%. Enterotoxin C was produced in broths inoculated with 108 cells per ml and above and having initial pH ranges of 4.00 to 9.83, 4.40 to 9.43, 4.50 to 8.55 and respective NaCl concentrations of 0, 4, and 8%. In the presence of 10% NaCl, the pH range supporting enterotoxin C production was 5.45 to 7.30 for an inoculum level of 108 cells per ml and 6.38 to 7.30 for 3.6 × 106 cells per ml. In repeated experiments in which the inoculum contained 108 cells per ml, we failed to demonstrate enterotoxin C production in broths with 12% NaCl and a pH range of 4.50 to 8.55 and concentrated up to 14 times. The effect of NaCl on enterotoxin C production followed the same pattern as its effect on enterotoxin B production. As the concentration of NaCl increased from 0 to 10%, yields of enterotoxin B and C decreased to undetectable amounts. PMID:5574320

  15. Chitosan inhibits enterotoxigenic Clostridium perfringens type A in growth medium and chicken meat.

    Science.gov (United States)

    Alnoman, Maryam; Udompijitkul, Pathima; Sarker, Mahfuzur R

    2017-06-01

    Clostridium perfringens is a spore-forming bacterium and a major cause of bacterial food-borne illness. In this study, we evaluated the inhibitory effects of chitosan against spore germination, spore outgrowth and vegetative growth of C. perfringens food poisoning (FP) isolates. Chitosan of differing molecular weights inhibited germination of spores of all tested FP isolates in a KCl germinant solution containing 0.1 mg/ml chitosan at pH 4.5. However, higher level (0.25 mg/ml) of chitosan was required to effectively arrest outgrowth of the germinated C. perfringens spores in Tripticase-yeast extract-glucose (TGY) medium. Furthermore, chitosan (1.0 mg/ml) was bacteriostatic against vegetative cells of C. perfringens in TGY medium. Although chitosan showed strong inhibitory activities against C. perfringens in laboratory medium, higher levels (2.0 mg/g) were required to achieve similar inhibition of spores inoculated into chicken meat. In summary, the inhibitory effects of chitosan against C. perfringens FP isolates was concentration dependent, and no major difference was observed when using different molecule weight chitosan as an inhibitor. Our results contribute to a better understanding on the potential application of chitosan in cooked meat products to control C. perfringens-associated disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Staphylococcus aureus growth and enterotoxin production in different types of milk

    Directory of Open Access Journals (Sweden)

    Bohdana Janštová, Jr.

    2012-01-01

    Full Text Available The aim of our study was to assess Staphylococcus aureus growth and the time of first detection of staphylococcal enterotoxins type A, B and C (SEA, SEB, SEC in different type of milk, depending on the strain and storage conditions. Raw, pasteurized, and UHT milk were inoculated with three strains of S. aureus, and growth patterns were determined by the plate method in accordance with EN ISO 6888-1. Baird-Parker agar medium was used for the detection of S. aureus and the Enzyme Linked Fluorescent Assay (ELFA used with a miniVIDAS analyzer tested the production of staphylococcal enterotoxins. The results of model experiments showed the dependence of the growth rate and subsequent production of staphylococcal enterotoxins on incubation (storage temperature, S. aureus strain, and type of milk. A significant finding was that the growth of S. aureus and production of enterotoxins in raw milk was inhibited by natural microflora, and production of enterotoxins was therefore not detected in raw milk within 102 hours of storage either at 15 °C or 22 °C. The highest risk of SEs production is associated with secondary contamination of pasteurized and UHT milk when stored at room temperature, where production was first detected after 12 hours of incubation.

  17. Staphylococcus aureus Enterotoxin A Gene Isolated From Raw Red Meat and Poultry in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Sarrafzadeh Zargar

    2014-07-01

    Full Text Available Background: Staphylococcus aureus is the most prevalent infectious agent of food materials. Enterotoxin producing types of S. aureus cause well-known food-borne disease. Staphylococcal Enterotoxin A (SEA is the most important agent of gastroenteritis. Objectives: The present study aimed to screen the raw meat samples collected from different regions of Tehran for S. aureus infection and type of encoding enterotoxin. Materials and Methods: Hundred and eighty six meat samples were collected randomly from city dealers and transferred to laboratory within screw cap containers. The samples were first cultured according to the standard bacteriological methods and then S. aureus isolates were identified using standard bacteriological tests. The isolates were subjected to Polymerase Chain Reaction (PCR to detect gene encoding SEA. Results: Staphylococcus aureus isolated from 29 (15.6% meat samples including beef 14.8%, raw lamb 15%, raw chicken 15.7% and raw turkey 16.6%. Using special primer sets proved that the species isolated from five samples (two raw chicken, two raw beef and one raw turkey encoded enterotoxin A. Conclusions: Although staphylococcal contamination within food material is more or less a routine, but detection of enterotoxin encoding species from raw meat samples is alarming for health authorities. These data highlight the importance of periodic surveillance of raw meat distributed among ordinary consumers.

  18. Uterine Sarcoma Presenting with Sepsis from Clostridium perfringens Endometritis in a Postmenopausal Woman

    Directory of Open Access Journals (Sweden)

    Mary J. Kao

    2018-01-01

    Full Text Available Clostridium perfringens is an anaerobic gram positive rod that is found in normal vaginal and cervical flora in 1–10% of healthy women. Uterine infection with Clostridium perfringens is seen rarely but is often related to underlying uterine pathology and can progress quickly to sepsis. Early recognition of sepsis, prompt treatment with antibiotics, and source control with surgical management allow for optimal chance of recovery. We present a case of a postmenopausal woman who presented with sepsis, vaginal bleeding, and back pain who was found to have Clostridium perfringens infection in the setting of undifferentiated uterine sarcoma.

  19. Antimicrobial susceptibility of Clostridium perfringens isolated from piglets with or without diarrhea in Brazil

    Science.gov (United States)

    Salvarani, Felipe Masiero; Silveira Silva, Rodrigo Otávio; Pires, Prhiscylla Sadanã; da Costa Cruz Júnior, Eduardo Coulaud; Albefaro, Isabella Silva; de Carvalho Guedes, Roberto Maurício; Faria Lobato, Francisco Carlos

    2012-01-01

    The minimum inhibitory concentration (MIC) was determined for 13 antibiotics against Clostridium perfringens isolated from Brazilian piglets. The collection of isolates was performed in June to October 2010. All isolates were susceptible to amoxicillin and ceftiofur, whereas most were resistant to tetracycline and lincomycin. Avilamycin and narasin were more effective against isolates from non-diarrheic than from diarrheic piglets. The other antimicrobials were less active in need of high concentrations to inhibit the growth of the C. perfringens type A. These results suggest the need for further studies evaluating molecular factors related to the antimicrobial resistance of C. perfringens. PMID:24031924

  20. Cyclic Di-GMP Binding by an Assembly ATPase (PilB2) and Control of Type IV Pilin Polymerization in the Gram-Positive Pathogen Clostridium perfringens.

    Science.gov (United States)

    Hendrick, William A; Orr, Mona W; Murray, Samantha R; Lee, Vincent T; Melville, Stephen B

    2017-05-15

    The Gram-positive pathogen Clostridium perfringens possesses type IV pili (TFP), which are extracellular fibers that are polymerized from a pool of pilin monomers in the cytoplasmic membrane. Two proteins that are essential for pilus functions are an assembly ATPase (PilB) and an inner membrane core protein (PilC). Two homologues each of PilB and PilC are present in C. perfringens , called PilB1/PilB2 and PilC1/PilC2, respectively, along with four pilin proteins, PilA1 to PilA4. The gene encoding PilA2, which is considered the major pilin based on previous studies, is immediately downstream of the pilB2 and pilC2 genes. Purified PilB2 had ATPase activity, bound zinc, formed hexamers even in the absence of ATP, and bound the second messenger molecule cyclic di-GMP (c-di-GMP). Circular dichroism spectroscopy of purified PilC2 indicated that it retained its predicted degree of alpha-helical secondary structure. Even though no direct interactions between PilB2 and PilC2 could be detected in vivo or in vitro even in the presence of c-di-GMP, high levels of expression of a diguanylate cyclase from C. perfringens (CPE1788) stimulated polymerization of PilA2 in a PilB2- and PilC2-dependent manner. These results suggest that PilB2 activity is controlled by c-di-GMP levels in vivo but that PilB2-PilC2 interactions are either transitory or of low affinity, in contrast to results reported previously from in vivo studies of the PilB1/PilC1 pair in which PilC1 was needed for polar localization of PilB1. This is the first biochemical characterization of a c-di-GMP-dependent assembly ATPase from a Gram-positive bacterium. IMPORTANCE Type IV pili (TFP) are protein fibers involved in important bacterial functions, including motility, adherence to surfaces and host cells, and natural transformation. All clostridia whose genomes have been sequenced show evidence of the presence of TFP. The genetically tractable species Clostridium perfringens was used to study proteins involved in

  1. Sub-inhibitory stress with essential oil affects enterotoxins production and essential oil susceptibility in Staphylococcus aureus.

    Science.gov (United States)

    Turchi, Barbara; Mancini, Simone; Pistelli, Luisa; Najar, Basma; Cerri, Domenico; Fratini, Filippo

    2018-03-01

    Fourteen wild strains of Staphylococcus aureus positive for gene sea were tested for enterotoxins production and the minimum inhibitory concentration of Leptospermum scoparium, Origanum majorana, Origanum vulgare, Satureja montana and Thymus vulgaris essential oils (EOs) were determined. After this trial, bacteria stressed with sub-inhibitory concentration of each EO were tested for enterotoxins production by an immunoenzymatic assay and resistance to the same EO. Oregano oil exhibited the highest antibacterial activity followed by manuka and thyme oils. After the exposure to a sub-inhibitory concentration of EOs, strains displayed an increased sensitivity in more than 95% of the cases. After treatment with oregano and marjoram EOs, few strains showed a modified enterotoxins production, while 43% of the strains were no longer able to produce enterotoxins after treatment with manuka EO. The results obtained in this study highlight that exposure to sub-inhibitory concentration of EO modifies strains enterotoxins production and EOs susceptibility profile.

  2. Receptors and cGMP signalling mechanism for E. coli enterotoxin in opossum kidney

    International Nuclear Information System (INIS)

    Forte, L.R.; Krause, W.J.; Freeman, R.H.

    1988-01-01

    Receptors for the heat-stable enterotoxin produced by Escherichia coli were found in the kidney and intestine of the North American opossum and in cultured renal cell lines. The enterotoxin markedly increased guanosine 3',5'-cyclic monophosphate (cGMP) production in slices of kidney cortex and medulla, in suspensions of intestinal mucosa, and in the opossum kidney (OK) and rat kangaroo kidney (PtK-2) cell lines. In contrast, atrial natriuretic factor elicited much smaller increases in cGMP levels of kidney, intestine, or cultured kidney cell lines. The enterotoxin receptors in OK cells had a molecular mass of approximately 120 kDa when measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of receptors crosslinked with 125 I-enterotoxin. The occurrence of receptors for the E. coli peptide in OK implies that these receptors may be involved in the regulation of renal tubular function in the opossum. E. coli enterotoxin caused a much larger increase in urine cGMP excretion than did atrial natriuretic factor when these peptides were injected intravenously into opossums. However, atrial natriuretic factor elicited a marked diuresis, natriuresis, and increased urinary excretion of calcium, phosphate, potassium, and magnesium. In contrast, the enterotoxin did not acutely influence OK fluid and electrolyte excretion. Thus the substantial increase in cGMP synthesis produced by the bacterial peptide in OK cortex and medulla in vitro and the increased renal excretion of cGMP in vivo were not associated with changes in electrolyte or water excretion. Whether cGMP represents a second messenger molecule in the kidney is an interesting question that was raised but not answered in this series of experiments

  3. Whole-body distribution and radiation dosimetry of the dopamine transporter radioligand [{sup 11}C]PE2I in healthy volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Maria-Joao [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France)]. E-mail: maria-joao.ribeiro@cea.fr; Ricard, Marcel [Service de Physique, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France); Lievre, Marie-Angele [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France); Bourgeois, Sandrine [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France); Emond, Patrick [INSERM U316, Laboratoire de Biophysique medicale et pharmaceutique, UFR des Sciences Pharmaceutiques, 37200 Tours (France); Gervais, Philippe [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France); Dolle, Frederic [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France); Syrota, Andre [Service Hospitalier Frederic Joliot, Institut d' Imagerie Biomedicale, Direction des Sciences du Vivant, Commissariat a l' Energie Atomique, F-91406 Orsay (France)

    2007-05-15

    Introduction: This study reports on the biodistribution and radiation dosimetry of a cocaine analog, the (E)-N-(3-iodoprop-2-enyl)-2{beta}-carbomethoxy-3{beta}-(4'-tolyl)nortropane (PE2I), labeled with carbon 11 ([{sup 11}C]PE2I). [{sup 11}C]PE2I is used in positron emission tomography (PET) for examination of the dopamine neuronal transporter (DAT). DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuroprotective therapeutics, and, typically, these studies required several successive PET scans. Methods: In three healthy male volunteers, whole-body scans were performed up to 2 h following intravenous injection of 321{+-}6 MBq of [{sup 11}C]PE2I. For each subject, regions of interest were defined over all visible organs to generate time-activity curves and calculate the percentage of injected activity. Time-activity data were fitted to a monoexponential model, as an uptake phase followed by a mono-exponential washout, or bi-exponential model to obtain residence times. With the use of the MIRD method, several source organs were considered in estimating residence time and mean effective radiation absorbed doses. Results: Blood pressure and ECG findings remained unchanged after radioligand injection. The primary route of clearance was renal. Ten minutes after injection, high activities were observed in the kidneys, urinary-bladder, stomach, liver, salivary glands and brain. The urine bladder wall, stomach and liver received the highest absorbed doses. The average effective dose of [{sup 11}C]PE2I was estimated to be 6.4{+-}0.6 {mu}Sv/MBq. Conclusion: The amount of [{sup 11}C]PE2I required for adequate DAT PET imaging results in an acceptable effective dose equivalent permitting two or three repeated cerebral PET studies, with the injection of 222 MBq for each study.

  4. Whole-body distribution and radiation dosimetry of the dopamine transporter radioligand [11C]PE2I in healthy volunteers

    International Nuclear Information System (INIS)

    Ribeiro, Maria-Joao; Ricard, Marcel; Lievre, Marie-Angele; Bourgeois, Sandrine; Emond, Patrick; Gervais, Philippe; Dolle, Frederic; Syrota, Andre

    2007-01-01

    Introduction: This study reports on the biodistribution and radiation dosimetry of a cocaine analog, the (E)-N-(3-iodoprop-2-enyl)-2β-carbomethoxy-3β-(4'-tolyl)nortropane (PE2I), labeled with carbon 11 ([ 11 C]PE2I). [ 11 C]PE2I is used in positron emission tomography (PET) for examination of the dopamine neuronal transporter (DAT). DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuroprotective therapeutics, and, typically, these studies required several successive PET scans. Methods: In three healthy male volunteers, whole-body scans were performed up to 2 h following intravenous injection of 321±6 MBq of [ 11 C]PE2I. For each subject, regions of interest were defined over all visible organs to generate time-activity curves and calculate the percentage of injected activity. Time-activity data were fitted to a monoexponential model, as an uptake phase followed by a mono-exponential washout, or bi-exponential model to obtain residence times. With the use of the MIRD method, several source organs were considered in estimating residence time and mean effective radiation absorbed doses. Results: Blood pressure and ECG findings remained unchanged after radioligand injection. The primary route of clearance was renal. Ten minutes after injection, high activities were observed in the kidneys, urinary-bladder, stomach, liver, salivary glands and brain. The urine bladder wall, stomach and liver received the highest absorbed doses. The average effective dose of [ 11 C]PE2I was estimated to be 6.4±0.6 μSv/MBq. Conclusion: The amount of [ 11 C]PE2I required for adequate DAT PET imaging results in an acceptable effective dose equivalent permitting two or three repeated cerebral PET studies, with the injection of 222 MBq for each study

  5. Organ Culture as a Model System for Studies on Enterotoxin Interactions with the Intestinal Epithelium

    DEFF Research Database (Denmark)

    Lorenzen, Ulver Spangsberg; Hansen, Gert H; Danielsen, E Michael

    2015-01-01

    Studies on bacterial enterotoxin-epithelium interactions require model systems capable of mimicking the events occurring at the molecular and cellular levels during intoxication. In this chapter, we describe organ culture as an often neglected alternative to whole-animal experiments or enterocyte......-like cell lines. Like cell culture, organ culture is versatile and suitable for studying rapidly occurring events, such as enterotoxin binding and uptake. In addition, it is advantageous in offering an epithelium with more authentic permeability/barrier properties than any cell line, as well...

  6. Clostridium perfringens Antigens Recognized by Broiler Chickens Immune to Necrotic Enteritis▿

    OpenAIRE

    Kulkarni, R. R.; Parreira, V. R.; Sharif, S.; Prescott, J. F.

    2006-01-01

    Little is known about immunity to necrotic enteritis (NE) in chickens. A recent study of broiler chickens showed that protection against NE was associated with infection-immunization with virulent but not with avirulent Clostridium perfringens.In the current study, six secreted antigenic proteins unique to virulent C. perfringens that reacted to serum antibodies from immune birds were identified by mass spectrophotometry; three of these proteins are part of the VirR-VirS regulon.

  7. Alpha toxin specific PCR for detection of toxigenic strains of Clostridium perfringens in Poultry

    Directory of Open Access Journals (Sweden)

    Malmarugan Shanmugasamy

    2012-12-01

    Full Text Available Aim : Isolation of clostridium perfirngens from necrotic enteritis cases in poultry and confirmation by alpha toxin specific PCR Materials and methods: Robertson cooked meat medium with Brain Heart Infusion broth was used for isolation of C. perfringens from intestinal contents of necrotic enteritis suspected birds. Positive cultures from perfringens agar were further confirmed by biochemical tests and subjected to alpha toxin specific PCR. Results: Twenty Clostridium perfringens isolates were isolated from intestinal contents of thirty five NE suspected birds. Out of the twenty isolates, fourteen were isolated from commercial broilers of 2 to 6 wk of age and six from commercial layers of 9 to 15 wk of age. Frequency of isolation of C. perfringens was more with Robertson cooked meat medium with BHI broth than thioglycollate broth alone. When positive cultures were streaked on to clostridial agar appreciable luxuriant growths were obtained and the selective streaking of these colonies on perfringens agar with supplements revealed rough and black colonies with sulphate reduction. The isolates produced rough and black colonies with sulphate reduction on perfringens agar, double zone haemolysis on sheep blood agar, stormy clot fermentation on milk medium and opalescence on egg yolk medium. The isolates were found negative for oxidase, catalase, liquefied gelatin, fermented glucose, maltose, lactose and sucrose except mannitol. All the fourteen isolates obtained from commercial broilers proved the alpha toxin producing strains of C. perfringens when they were subjected to alpha toxin specific PCR. Conclusion : This study revealed alpha toxin specific PCR is highly useful for detection of toxigenic strains of Clostridium perfringens in poultry [Vet. World 2012; 5(6.000: 365-368

  8. Characterization of Clostridium perfringens isolated from mammals and birds from Guwahati city, India

    Directory of Open Access Journals (Sweden)

    Mafruza S Rahman

    2012-01-01

    Full Text Available Of the 102 samples collected from mammals and birds, both domestic and captive wild, 48 were found to be positive for Clostridium perfringens. Most of the mammal isolates (84.38% appeared to have been collected from clinically affected animals, while 33.33% of the bird samples were from clinically affected and 21.43% from apparently healthy birds infected with C. perfringens. Isolates revealed high sensitivity to ciprofloxacin, enrofloxacin and norfloxacin. Among the isolated C. perfringens, 30 (62.50% showed DNase production. Hemolytic activity was recorded in 14 (24.16% of the isolates and 28 (58.33% showed phospholipase C production. All the phospholipase C positive isolates revealed the presence of cpa gene encoding alpha (α toxin. Of the 102 samples collected from mammals and birds, both domestic and captive wild, 48 were found to be positive for Clostridium perfringens. Most of the mammal isolates (84.38% appeared to have been collected from clinically affected animals, while 33.33% of the bird samples were from clinically affected and 21.43% from apparently healthy birds infected with C. perfringens. Isolates revealed high sensitivity to ciprofloxacin, enrofloxacin and norfloxacin. Among the isolated C. perfringens, 30 (62.50% showed DNase production. Hemolytic activity was recorded in 14 (24.16% of the isolates and 28 (58.33% showed phospholipase C production. All the phospholipase C positive isolates revealed the presence of cpa gene encoding α toxin.

  9. Bacillus subtilis and yeast cell wall improve the intestinal health of broilers challenged by Clostridium perfringens.

    Science.gov (United States)

    Li, Z; Wang, W; Lv, Z; Liu, D; Guo, Y

    2017-12-01

    1. The objective was to investigate the effects of Bacillus subtilis, yeast cell wall (YCW) and their combination on intestinal health of broilers challenged by Clostridium perfringens over a 21-d period. 2. Using a 5 × 2 factorial arrangement of treatments, 800 1-d-old male Cobb 500 broilers were used to study the effects of feed additives (without additive or with zinc bacitracin, B. subtilis, YCW, and the combination of B. subtilis and YCW), pathogen challenge (without or with Clostridium perfringens challenge), and their interactive effects. 3. C. perfringens infection increased intestinal lesions scores, damaged intestinal histomorphology, increased serum endotoxin concentration, cytokine mRNA expression and intestinal population of C. perfringens and Escherichia coli and decreased ileal bifidobacteria numbers. The 4 additives decreased serum endotoxin. Zinc bacitracin tended to decrease cytokine mRNA expression and the intestinal number of C. perfringens and E. coli. B. subtilis, YCW and their combination increased cytokine mRNA expression. B. subtilis and YCW decreased the number of C. perfringens and E. coli in the ileum, and their combination decreased pathogens numbers in the ileum and caecum. 4. In conclusion, B. subtilis, YCW and their combination improved the intestinal health of NE-infected broilers, and could be potential alternatives to antibiotics.

  10. Application of Lactobacillus johnsonii expressing phage endolysin for control of Clostridium perfringens.

    Science.gov (United States)

    Gervasi, T; Lo Curto, R; Minniti, E; Narbad, A; Mayer, M J

    2014-10-01

    Clostridium perfringens is frequently found in food and the environment and produces potent toxins that have a negative impact on both human and animal health and particularly on the poultry industry. Lactobacillus johnsonii FI9785, isolated from the chicken gastrointestinal tract, has been demonstrated to exclude Cl. perfringens in poultry. We have investigated the interaction of wild-type Lact. johnsonii FI9785 or an engineered strain expressing a cell wall-hydrolysing endolysin with Cl. perfringens in vitro, using a batch culture designed to simulate human gastrointestinal tract conditions. Co-culture experiments indicated that acid production by Lact. johnsonii is important in pathogen control. The co-culture of the endolysin-secreting Lact. johnsonii with Cl. perfringens showed that the engineered strain had the potential to control the pathogen, but the ability to reduce Cl. perfringens numbers was not consistent. Results obtained indicate that survival of high numbers of Lact. johnsonii will be essential for effective pathogen control. Significance and impact of the study: The bacterium Lactobacillus johnsonii FI9785 reduces numbers of the pathogen Clostridium perfringens in vitro. Biocontrol was improved by engineering the strain to produce and export a cell wall-hydrolysing endolysin, but good survival of the producer strain is essential. The production of bacteriophage endolysins by commensal bacteria has the potential to improve competitive exclusion of pathogens in the gastrointestinal tract. © 2014 The Society for Applied Microbiology.

  11. Occurrence of Clostridium perfringens contamination in poultry feed ingredients: Isolation, identification and its antibiotic sensitivity pattern

    Directory of Open Access Journals (Sweden)

    Shanmugasundaram Udhayavel

    2017-09-01

    Full Text Available This work has been undertaken to study the occurrence of Clostridium perfringens contamination in the poultry feed ingredients and find out its in-vitro antibiotic sensitivity pattern to various antimicrobial drugs. Two hundred and ninety-eight poultry feed ingredient samples received at Poultry Disease Diagnosis and Surveillance Laboratory, Namakkal, Tamil Nadu in South India were screened for the presence of C. perfringens. The organisms were isolated in Perfringens agar under anaerobic condition and subjected to standard biochemical tests for confirmation. In vitro antibiogram assay has been carried out to determine the sensitivity pattern of the isolates to various antimicrobial drugs. One hundred and one isolates of C. perfringens were obtained from a total of 298 poultry feed ingredient samples. Overall positivity of 33.89% could be made from the poultry feed ingredients. Highest level of C. perfringens contamination was detected in fish meal followed by bone meal, meat and bone meal and dry fish. Antibiogram assay indicated that the organisms are highly sensitive to gentamicin (100%, chlortetracycline (96.67%, gatifloxacin (93.33%, ciprofloxacin (86.67%, ofloxacin (86.67% and lincomycin (86.67%. All the isolates were resistant to penicillin-G. Feed ingredients rich in animal proteins are the major source of C. perfringens contamination.

  12. Incidence and tracking of Clostridium perfringens through an integrated broiler chicken operation.

    Science.gov (United States)

    Craven, S E; Cox, N A; Bailey, J S; Cosby, D E

    2003-01-01

    Clostridium perfringens has been shown to be widespread in the broiler chicken hatchery, grow-out, and processing operations. In a previous study, ribotypes of certain strains of C. perfringens isolated from processed chicken carcasses were shown to match ribotypes isolated from paper pad lining trays used to transport commercial chicks from the hatchery to the grow-out facility on the farm. These results suggest that C. perfringens contaminating the processed product could originate from facilities in the integrated poultry operation prior to grow out. In this study, samples were collected from the breeder farm, hatchery, previous grow-out flock, during grow out and after processing. In the first trial, C. perfringens was recovered from the breeder farms, the hatchery, previous grow-out flock, grow-out flock at 3 weeks of age, grow-out flock at 5 weeks of age, from processed carcasses, and from the breeder farm after processing in 4%, 30%, 4%, 0%, 2% and 16%, and 4% of the samples, respectively. In the second trial, the incidence of C. perfringens in samples collected from breeder farms, the hatchery, previous grow-out flock, grow-out flock at 3 weeks of age, grow-out flock at 5 weeks of age, and fromprocessed carcasses was 38%, 30%, 32%, 8%, 4%, and 8%, respectively. The genetic relatedness of the isolated strains as determined by ribotyping suggests that C. perfringens may be transmitted between facilities within the integrated broiler chicken operation.

  13. ELIMINATION OF CLOSTRIDIUM PERFRINGENS DURING SURPLUS ACTIVATED SLUDGE HANDLING

    Directory of Open Access Journals (Sweden)

    Klaudiusz Grűbel

    2014-10-01

    Basis on the results of the research was concluded that microwave radiation (700W and 900W shows disintegration action expressed in COD value in the supernatant increase: 12 times increase value of COD with power 700W and 13 times for 900W radiation power. Electromagnetic wave contributed to partial higienisation of surplus activated sludge. The number of Clostridium perfringens decrease about 52% and 56% during the 120s of higienisation process with power 700W and 900W, respectively. Reduction of the overall number of bacteria under the influence of microwave radiation was 42% and 51% (respectively for 700W and 900W, and sticks from the family Enterobacteriaceae from 54% to 70% depending on the power of radiation, the time of operation and biochemical properties.

  14. Use of inactivated E.Coli enterotoxins to enhance respiratory mucosal adjuvanticity during vaccination in swine

    Science.gov (United States)

    In order to augment responses to respiratory vaccines in swine, various adjuvants were intranasally co-administered with an antigen to pigs. Detoxified E. coli enterotoxins LTK63 and LTR72 enhanced mucosal and systemic immunity to the model peptide, exhibiting their efficacy as mucosal adjuvants for...

  15. Production of enterotoxins of Staphylococcus spp. isolated from samples of sheep milk

    Directory of Open Access Journals (Sweden)

    František Zigo

    2014-02-01

    Full Text Available In our study was followed occurrence of mastitis in herd of 430 sheep of breed zoslachtena valaska with hand milking technology examined two times during one lactation season. Individual examination consisted from clinical examination of udder and microbiological examination of milk samples. By PCR was determined presence of genes coding production of enterotoxins, and by ELISA methods production individual types of enterotoxins. From individual forms of mastitis were frequently detected subacute (6.7%, subclinical (5.7% and acute (2.9%. The coagulase-negative staphylococci (CNS were identified in 102 (65.4% from all 156 positive isolates. The CNS and S. aureus caused subacute (5.1%, subclinical (3.9% and acute (2.4% forms of mastitis. The most frequently isolated were S. epidermidis, followed by S. chromogenes and S. xylosus from ewes with subacute and subclinical mastitis. From acute and chronical forms of mastitis were  predominantly isolated S. aureus, S. uberis and S. epidermidis. The production of staphylococcal enterotoxins (SE - SEA, SEB, SEC, SED and the presence of genes sec (3, sea (2, seb (2 and sed (2 were determined in S. aureus, S. epidermidis, S. schleiferi and S. chromogenes, respectively. The results suggested on the high occurrence (12.4% of subacute and subclinical forms. Confirmed production of enterotoxins and presence of genes coding their production present a risk for human health and decreased a quality of milk and products from sheep´s milk.

  16. Lung and pharyngeal abscess caused by enterotoxin G- and I-producing Staphylococcus aureus.

    Science.gov (United States)

    Barnett, S Y; Hattotuwa, K L; Teare, L

    2012-05-01

    We report a particularly serious case of extensive meticillin sensitive Staphylococcal lung and pharyngeal abscess. Our patient had no significant risk factors for severe infection. The detection of enterotoxin G and I here suggest that when present together, these toxins work synergistically to produce a more virulent strain of Staphylococcus aureus. Copyright © 2011. Published by Elsevier Ltd.

  17. Lab-on-a-chip for label free biological semiconductor analysis of Staphylococcal Enterotoxin B

    NARCIS (Netherlands)

    Yang, Minghui; Sun, Steven; Bruck, Hugh Alan; Kostov, Yordan; Rasooly, Avraham

    2010-01-01

    We describe a new lab-on-a-chip (LOC) which utilizes a biological semiconductor (BSC) transducer for label free analysis of Staphylococcal Enterotoxin B (SEB) (or other biological interactions) directly and electronically. BSCs are new transducers based on electrical percolation through a

  18. Inhibitory effect of totarol on exotoxin proteins hemolysin and enterotoxins secreted by Staphylococcus aureus.

    Science.gov (United States)

    Shi, Ce; Zhao, Xingchen; Li, Wenli; Meng, Rizeng; Liu, Zonghui; Liu, Mingyuan; Guo, Na; Yu, Lu

    2015-10-01

    Staphylococcus aureus (S. aureus) causes a wide variety of infections, which are of major concern worldwide. S. aureus produces multiple virulence factors, resulting in food infection and poisoning. These virulence factors include hyaluronidases, proteases, coagulases, lipases, deoxyribonucleases and enterotoxins. Among the extracellular proteins produced by S. aureus that contribute to pathogenicity, the exotoxins α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) are thought to be of major significance. Totarol, a plant extract, has been revealed to inhibit the proliferation of several pathogens effectively. However, there are no reports on the effects of totarol on the production of α-hemolysin, SEA or SEB secreted by S. aureus. The aim of this study was to evaluate the effects of totarol on these three exotoxins. Hemolysis assay, western blotting and real-time reverse transcriptase-PCR assay were performed to identify the influence of graded subinhibitory concentrations of totarol on the production of α-hemolysin and the two major enterotoxins, SEA and SEB, by S. aureus in a dose-dependent manner. Moreover, an enzyme linked immunosorbent assay showed that the TNF-α production of RAW264.7 cells stimulated by S. aureus supernatants was inhibited by subinhibitory concentrations of totarol. Form the data, we propose that totarol could potentially be used as a promising natural compound in the food and pharmaceutical industries.

  19. Rauvolfia grandiflora (Apocynaceae extract interferes with staphylococcal density, enterotoxin production and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Lanamar de Almeida Carlos

    2010-10-01

    Full Text Available Staphylococci bacteria are involved in many human and animal infections and development of alternative antimicrobial drugs against pathogenic bacteria is of great interest to the pharmaceutical industry. This study investigated the in vitro effect of Rauvolfia grandiflora methanol extract (root bark fraction (RGE on the density of ATCC strains of Staphylococcus aureus and Staphylococcus epidermidis, and a clinical enterotoxin-producer, S. aureus bovine strain. The alkaloid, isoreserpiline, obtained from dichloromethane extract of R. grandiflora was ineffective against the strains tested. After incubation of staphylococci strains in the presence of 1.2 mg.mL-1 RGE, a significant inhibition of cell growth was observed using both spectrophotometry and ELISA assays. Twelve drugs were evaluated for their antimicrobial effects on culture RGE-treated cells using the disk diffusion method. Penicillin resistant strains became sensitive to the drug after RGE treatment. Furthermore, enterotoxin production by RGE-treated S. aureus was evaluated using a standardized ELISA method. Although staphylococcal LSA 88 bovine strain cells remained viable after exposure to the extract, enterotoxin production was precluded in 20% after RGE treatment. Significant interference in staphylococci cell density, drug sensitivity and enterotoxin secretion was observed after treatment. The study highlights the necessity to find new methods of disease prevention and new antibiotic therapies against staphylococcal infections.

  20. Rauvolfia grandiflora (apocynaceae) extract interferes with staphylococcal density, enterotoxin production and antimicrobial activity.

    Science.gov (United States)

    de Almeida Carlos, Lanamar; da Silva Amaral, Kenas Aguiar; Curcino Vieira, Ivo José; Mathias, Leda; Braz-Filho, Raimundo; Silva Samarão, Solange; Vieira-da-Motta, Olney

    2010-07-01

    Staphylococci bacteria are involved in many human and animal infections and development of alternative antimicrobial drugs against pathogenic bacteria is of great interest to the pharmaceutical industry. This study investigated the in vitro effect of Rauvolfia grandiflora methanol extract (root bark fraction) (RGE) on the density of ATCC strains of Staphylococcus aureus and Staphylococcus epidermidis, and a clinical enterotoxin-producer, S. aureus bovine strain. The alkaloid, isoreserpiline, obtained from dichloromethane extract of R. grandiflora was ineffective against the strains tested. After incubation of staphylococci strains in the presence of 1.2 μg.mL(-1) RGE, a significant inhibition of cell growth was observed using both spectrophotometry and ELISA assays. Twelve drugs were evaluated for their antimicrobial effects on culture RGE-treated cells using the disk diffusion method. Penicillin resistant strains became sensitive to the drug after RGE treatment. Furthermore, enterotoxin production by RGE-treated S. aureus was evaluated using a standardized ELISA method. Although staphylococcal LSA 88 bovine strain cells remained viable after exposure to the extract, enterotoxin production was precluded in 20% after RGE treatment. Significant interference in staphylococci cell density, drug sensitivity and enterotoxin secretion was observed after treatment. The study highlights the necessity to find new methods of disease prevention and new antibiotic therapies against staphylococcal infections.

  1. Expression of Staphylococcal Enterotoxins under Stress Encountered during Food Production and Preservation.

    Science.gov (United States)

    Schelin, Jenny; Susilo, Yusak Budi; Johler, Sophia

    2017-12-15

    Staphylococcal food poisoning (SFP) is the most prevalent cause of food-borne intoxications worldwide. Consumption of enterotoxins preformed in food causes violent vomiting and can be fatal in children and the elderly. While being repressed by competing bacteria in most matrices, Staphylococcus aureus benefits from crucial competitive advantages in foods with high osmolarity or low pH. During recent years, the long-standing belief in the feasibility of assessing SFP risk based on colony-forming units of S. aureus present in food products has been disproven. Instead, researchers and food business operators are acutely aware of the imminent threat arising from unforeseeable enterotoxin production under stress conditions. This paradigm shift led to a variety of new publications enabling an improved understanding of enterotoxin expression under stress conditions encountered in food. The wealth of data provided by these studies is extremely diverse, as it is based on different methodological approaches, staphylococcal strains, stressors, and enterotoxins. Therefore, in this review, we aggregated and critically evaluated the complex findings of these studies, to provide readers with a current overview of the state of research in the field.

  2. The olive compound 4-hydroxytyrosol inactivates Staphyloccoccus aureus bacteria and Staphylococcal enterotoxin A (SEA)

    Science.gov (United States)

    The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal enterotoxin A (SEA), a single chain protein which consists of 233 amino acid residues with a molecular weight of 27,078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, ...

  3. Cloning and Expression of Nano Body Gene against Enterotoxin B of Staphylococcus Aureus

    Directory of Open Access Journals (Sweden)

    Zahra Tavassoli

    2017-02-01

    Full Text Available Background & Objectives: Staphylococcus aureus bacteria causes many different diseases by secretion of various enterotoxins. Therefore, it is necessary to develop ways that facilitate the detection of enterotoxins. Nowadays, immunochemical methods which are based on monoclonal antibody technology are used. The heavy chain antibodies that are called VHH or Nano body were found in blood serum of the Camelidae family. The unique properties of this antibody such as their binding to small molecules like toxins make them attractive candidates for the development of immunodiagnostic tests. The present study was done to achieve a VHH molecules against Staphylococcus enterotoxin B. Materials & Methods: Freighting phage library for isolate private Nano bodies against enterotoxin B was done in previous works. Next, pCANTAB 5E vector that consists VHH, extracted from E.coli bacteria strain xl1blue, and after doing PCR process with relative primers, sub cloning in pET21a(+ as an expression vector with cut sites NdeI and XhoI was done. Transformation in E.coli bacteria strain BL21(DE3 was done. Then, the cells effected with IPTG and producing time, and other terms were optimized. Finally, the expression of the protein with SDS-PAGE and western blot techniques was evaluated. Result: For proving cloning of nano body gene in pET21a (+ vector, nucleotide sequence of gene was analyzed, and transforming to E.coli bacteria strain BL21(DE3 was successful. After inspiration, active protein in cell was seen by SDS-PAGE technique and proved by western blot. Conclusion: cloning, sub cloning, and nonabody expression were surveyed in this research. Production of this protein can help to develop new therapeutic methods and produce vaccine against enterotoxin B of Staphylococcus aureus

  4. [11C]PE2I: a highly selective radioligand for PET examination of the dopamine transporter in monkey and human brain

    International Nuclear Information System (INIS)

    Halldin, Christer; Erixon-Lindroth, Nina; Pauli, Stefan; Chou, Yuan-Hwa; Okubo, Yoshiro; Karlsson, Per; Lundkvist, Camilla; Olsson, Hans; Farde, Lars; Guilloteau, Denis; Emond, Patrick

    2003-01-01

    The aim of this study was to explore the potential of a new selective dopamine transporter (DAT) compound as a radioligand for positron emission tomography (PET) examination of DAT in the human brain. The high affinity DAT compound N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methylphenyl)nortropane (PE2I) was radiolabelled by the O-methylation approach and the binding was characterised by PET in cynomolgus monkeys and a healthy man. Metabolite levels in plasma were measured by gradient high-performance liquid chromatography. O-methylation of the corresponding free acid precursor with [ 11 C]methyl triflate gave high radiochemical yield (80%) and specific radioactivity (55 GBq/μmol). [ 11 C]PE2I binding in cynomolgus monkeys was nine times higher in the striatum than in the cerebellum at peak equilibrium, which appeared 55-65 min after injection. Displacement and pretreatment measurements using unlabelled β-CIT, GBR 12909, cocaine, citalopram and maprotiline confirmed that [ 11 C]PE2I binds selectively to DAT. In a preliminary study in one human subject the radioactivity ratios of the striatum and substantia nigra to the cerebellum were 10 and 1.8, respectively, at peak equilibrium, which appeared at 40-50 min and 20 min, respectively, after injection. The fraction of the total radioactivity in monkey and human plasma representing unchanged [ 11 C]PE2I was 15-20% at 40 min after injection. The present characterisation of binding in monkey and man suggests that [ 11 C]PE2I is a suitable PET radioligand for quantitative regional examination of DAT in man. (orig.)

  5. [{sup 11}C]PE2I: a highly selective radioligand for PET examination of the dopamine transporter in monkey and human brain

    Energy Technology Data Exchange (ETDEWEB)

    Halldin, Christer; Erixon-Lindroth, Nina; Pauli, Stefan; Chou, Yuan-Hwa; Okubo, Yoshiro; Karlsson, Per; Lundkvist, Camilla; Olsson, Hans; Farde, Lars [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, 17176, Stockholm (Sweden); Guilloteau, Denis; Emond, Patrick [INSERM U316 Universite Francois Rabelais, Tours (France)

    2003-09-01

    The aim of this study was to explore the potential of a new selective dopamine transporter (DAT) compound as a radioligand for positron emission tomography (PET) examination of DAT in the human brain. The high affinity DAT compound N-(3-iodoprop-2E-enyl)-2{beta}-carbomethoxy-3{beta}-(4-methylphenyl)nortropane (PE2I) was radiolabelled by the O-methylation approach and the binding was characterised by PET in cynomolgus monkeys and a healthy man. Metabolite levels in plasma were measured by gradient high-performance liquid chromatography. O-methylation of the corresponding free acid precursor with [{sup 11}C]methyl triflate gave high radiochemical yield (80%) and specific radioactivity (55 GBq/{mu}mol). [{sup 11}C]PE2I binding in cynomolgus monkeys was nine times higher in the striatum than in the cerebellum at peak equilibrium, which appeared 55-65 min after injection. Displacement and pretreatment measurements using unlabelled {beta}-CIT, GBR 12909, cocaine, citalopram and maprotiline confirmed that [{sup 11}C]PE2I binds selectively to DAT. In a preliminary study in one human subject the radioactivity ratios of the striatum and substantia nigra to the cerebellum were 10 and 1.8, respectively, at peak equilibrium, which appeared at 40-50 min and 20 min, respectively, after injection. The fraction of the total radioactivity in monkey and human plasma representing unchanged [{sup 11}C]PE2I was 15-20% at 40 min after injection. The present characterisation of binding in monkey and man suggests that [{sup 11}C]PE2I is a suitable PET radioligand for quantitative regional examination of DAT in man. (orig.)

  6. Muusikamaailm : CPE Bachi käsikirjad tagasi Saksamaale. Täna uusooper Londonis. Theodorakise ooperid plaadil. David Golub lahkunud. Preemia Palle Mikkelborgile / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2001-01-01

    Ukraina nõustus tagastama Saksamaale C.P.E. Bachi muusikakäsikirjad, mis Nõukogude Liidu armee sealt II Maailmasõja ajal ära viis. Inglise Rahvusooperis lavastuvast D.Saweri ooperist "From Morning to Midnight". M.Theodorakise kolm ooperit (antiiktriloogia "Elektra", "Antigone" ja "Medeia") ilmusid seoses maestro 75. juubeliga kaheksal CD-plaadil. Lühidalt D.Golubist. Põhjamaade Nõukogu tänavuse muusikapreemia võitis P.Mikkelborg

  7. Turn a diarrhoea toxin into a receptor-mediated therapy for a plethora of CLDN-4-overexpressing cancers

    International Nuclear Information System (INIS)

    Yao, Qin; Cao, Siyu; Li, Chun; Mengesha, Asferd; Low, Pauline; Kong, Beihua; Dai, Shuzhen; Wei, Mingqian

    2010-01-01

    Research highlights: → CLDN-4 is the high-affinity receptor for Clostridium perfringens enterotoxin (CPE). → The targeted toxin C-CPE-ETA' utilises the C-terminal fragment of CPE for binding. → C-CPE-ETA' rapidly binds to and internalises into CLDN-4 positive cancer cells. → C-CPE-ETA' has anti-cancer ability in a range of CLDN-4 positive cancers. -- Abstract: Molecular targeted therapy (MTT) represents the new generation of anti-cancer arsenals. In this study, we report an alternative approach using a hybrid toxin that utilises the high-affinity of receptor-binding fragment of Clostridium perfringens enterotoxin (CPE). CPE naturally binds to CLDN-4 through the C-terminal 30 amino acid. However, recent studies have shown that CLDN-4 is also overexpressed on a range of cancer cells. We thus constructed a cDNA comprising C-CPE and a well characterised toxic domain of Pseudomonas aeruginosa exotoxin A (C-CPE-ETA'). The recombinant C-CPE-ETA' fusion protein was shown to retain the specificity of binding to CLDN-4 and initiating rapid penetration into cytosol in five different CLDN-4 positive cancer cells (Breast-MCF7, Skin-A431, Colon-SW480, Prostate-PC3 and DU145) but not to CLDN-4 negative cells (Hela, HUVEC). C-CPE-ETA' was strongly cytotoxic towards CLDN-4 positive cancer cell, as opposed to cells lacking CLDN-4 expression. Furthermore, we demonstrated that the recombinant fusion protein had significant anti-cancer ability in CLDN-4 positive cancer models in vivo. Subcutaneously implanted MCF7 and SW480 xenograft tumours were significantly decreased or abolished after three repeated injection of the hybrid toxin. Taken together, our results convincingly show that the hybrid toxin targets CLDN-4 positive cancer through receptor-binding, and causes significant tumour cell apoptosis, suggesting its potential as an alternative molecular targeted therapy against a plethora of CLDN-4 positive cancers.

  8. Clostridium perfringens challenge and dietary fat type modifies performance, microbiota composition and histomorphology of the broiler chicken gastrointestinal tract

    DEFF Research Database (Denmark)

    Josefiak, Damian; Swiatkiewicz, S; Kieronczyk, B

    2016-01-01

    Belastung mit Clostridium perfringens und Futterfettquelle modifizieren die Leistung, die Zusammensetzung der Microbiota und die Histomorphologie des Verdauungstraktes beim Broiler......Belastung mit Clostridium perfringens und Futterfettquelle modifizieren die Leistung, die Zusammensetzung der Microbiota und die Histomorphologie des Verdauungstraktes beim Broiler...

  9. [Cloning of Clostridium perfringens alpha-toxin gene and extracellular expression in Escherichia coli].

    Science.gov (United States)

    Inoue, Masaharu; Kikuchi, Maho; Komoriya, Tomoe; Watanabe, Kunitomo; Kouno, Hideki

    2007-01-01

    Clostridium perfringens (C. perfringens) is a Gram-positive bacterial pathogen that widely propagets in the soil and the gastrointestinal tract of human and animals. This bacteria causes food poisoning, gas gangrene and other various range of infectious diseases. But there is no standard diagnosis method of C. perfringens. In order to develop a new type of immunoassay for clinical purpose, we studied expression and extracellular secretion of recombinant alpha-toxin having enzyme activity in E. coli expression system. Cloning was carried out after PCR amplification from C. perfringens GAI 94074 which was clinical isolate. Three kinds of fragment were cloned using pET100/D-TOPO vector. These fragments coded for ribosome binding site, signal peptide, and alpha-toxin gene respectively. Recombinant pET100 plasmid transformed into TOP 10 cells and the obtained plasmids were transformed into BL21 (DE3) cells. Then, the transformants were induced expression with IPTG. In conclusion, we successfully cloned, expressed and exteracellular secreted C. perfringens alpha-toxin containing signal peptide. Biologically, the obtained recombinant protein was positive for phospholipase C activity.

  10. 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.

  11. EPIDEMIOLOGIC INVESTIGATION OF CLOSTRIDIUM DIFFICILE AND CLOSTRIDIUM PERFRINGENS IN HEALTHY HORSES

    DEFF Research Database (Denmark)

    Schoster, Angelika; Arroyo, Luis; Staempfli, Henry

    Clostridium difficile and Clostridium perfringens are important causes of equine colitis but can also be found in healthy individuals. Epidemiologic information is restricted to cross-sectional studies of fecal shedding with little information on prevalence in gastrointestinal compartments other ...... supports results of previous studies that indicate this organism is rare in healthy horses.......Clostridium difficile and Clostridium perfringens are important causes of equine colitis but can also be found in healthy individuals. Epidemiologic information is restricted to cross-sectional studies of fecal shedding with little information on prevalence in gastrointestinal compartments other...... than feces and variability in shedding over time. The objectives were to investigate the presence of C. difficile and C. perfringens in healthy horses over time and assess prevalence in different gastrointestinal compartments. Feces were collected monthly from 25 horses for one year. Ingesta were...

  12. [Enterotoxin genes occurance among S. aureus strains isolated from inpatients and carriers].

    Science.gov (United States)

    Lawrynowicz-Paciorek, Maja; Kochman, Maria; Piekarska, Katarzyna; Wyrebiak, Agata; Potracka, Ewa; Leniak-Chmiel, Urszula; Magdziak, Agnieszka

    2006-01-01

    We examined 44 inpatients and 66 carriers Staphylococcus aureus strains, isolated in years 2002-2005, for the presence of 18 enterotoxin genes (se/sel) (by PCR), the ability for A-D enterotoxin production (by SET-RPLA) and antibiotic resistance distribution (by disc diffusion method). se/sel genes were detected in 90,9% of all strains, sea (70,5%) and selk and selq (52,3%) - among inpatients strains and egc (65,2%) - among carriers strains were the most frequently se/sel genes found. Positive results of SET-RPLA were consistent with PCR results. There was no correlation observed between antibiotic resistance and se/sel genes distribution among tested S. aureus strains.

  13. Prevalence of Staphylococcal Enterotoxins in Ready-to-Eat Foods Sold in Istanbul.

    Science.gov (United States)

    Ulusoy, Beyza H; Çakmak Sancar, Burcu; Öztürk, Muhsin

    2017-10-01

    The aim of this study was to investigate the prevalence of staphylococcal enterotoxins (SEs) in ready-to-eat (RTE) foods sold in Istanbul, Turkey. A total of 5,241 samples were randomly collected from various caterers, hotels, and restaurants from 2014 to 2016. The samples were classified into four groups: (i) various cooked RTE meat and vegetable meals, (ii) various RTE salads, charcuterie, and cold appetizers, (iii) various cooked RTE bakery products (pasta, pastries, pizza, pita, ravioli, etc.), and (iv) any cooked RTE sweets and desserts (pudding, custard, cream, ashura, etc.). The samples were examined for the presence of SEs by 3M Tecra Staph Enterotoxin Visual Immunoassay method, which is a manual enzyme-linked immunosorbent assay method. Among all samples, only 1 (0.019%) RTE meal (vegetable meal with meat) was found to be contaminated with SEs, a good result in terms of staphylococcal food poisoning risk and public health.

  14. The influence of radiation on the enterotoxin and thermoresistant deoxyribo-nuclease production by Staphylococcus sp

    International Nuclear Information System (INIS)

    Szulc, M.; Pliszka, A.; Peconek, J.

    1980-01-01

    Six strains of Staph. aureus present in the environment with and without protein were exposed to X rays in the doses range from 1 to 400 Gy. The production of enterotoxin and thermoresistant deoxyribonuclease by enterotoxic strains No 262 and 100 was determined. All the strains showed similar radiosensitivity to X rays. About 1 per cent of protein in the environment exposed to radiation increased the resistance of Staphylococcus strains. The doses of radiation from 1 to 400 Gy did not influence the enterotoxin A and B production by bacteria multiplied from those which had survived the radiation. The irradiation of the strains present in the environment without protein brought about a temporary inhibition of thermoresistant deoxyribonuclease production. (author)

  15. Selection and characterization of DNA aptamers against Staphylococcus aureus enterotoxin C1.

    Science.gov (United States)

    Huang, Yukun; Chen, Xiujuan; Duan, Nuo; Wu, Shijia; Wang, Zhouping; Wei, Xinlin; Wang, Yuanfeng

    2015-01-01

    Enterotoxins from pathogenic bacteria are known as the main reason that can cause the bacterial foodborne diseases. In this study, aptamers that bound to Staphylococcus aureus enterotoxin C1 (SEC1) with high affinity and selectivity were generated in vitro by twelve rounds of selection based on magnetic separation technology, with a low-level dissociation constant (Kd) value of 65.14 ± 11.64 nmol/L of aptamer C10. Aptamer-based quantification of SEC1 in the food sample by a graphene oxide (GO)-based method was implemented to investigate the potential of the aptamer against SEC1 with a limit of detection of 6 ng/mL. On the basis of this work, biosensors using the selected SEC1 aptamers as new molecular recognition elements could be applied for innovative determinations of SEC1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Cellular Uptake of the Clostridium perfringens Binary Iota-Toxin

    Science.gov (United States)

    Blöcker, Dagmar; Behlke, Joachim; Aktories, Klaus; Barth, Holger

    2001-01-01

    The binary iota-toxin is produced by Clostridium perfringens type E strains and consists of two separate proteins, the binding component iota b (98 kDa) and an actin-ADP-ribosylating enzyme component iota a (47 kDa). Iota b binds to the cell surface receptor and mediates the translocation of iota a into the cytosol. Here we studied the cellular uptake of iota-toxin into Vero cells. Bafilomycin A1, but not brefeldin A or nocodazole, inhibited the cytotoxic effects of iota-toxin, indicating that toxin is translocated from an endosomal compartment into the cytoplasm. Acidification (pH ≤ 5.0) of the extracellular medium enabled iota a to directly enter the cytosol in the presence of iota b. Activation by chymotrypsin induced oligomerization of iota b in solution. An average mass of 530 ± 28 kDa for oligomers was determined by analytical ultracentrifugation, indicating heptamer formation. The entry of iota-toxin into polarized CaCo-2 cells was studied by measuring the decrease in transepithelial resistance after toxin treatment. Iota-toxin led to a significant decrease in resistance when it was applied to the basolateral surface of the cells but not following application to the apical surface, indicating a polarized localization of the iota-toxin receptor. PMID:11292715

  17. Liver abscess and sepsis caused by Clostridium perfringens and Klebsiella oxytoca

    Directory of Open Access Journals (Sweden)

    Christoph Paasch

    Full Text Available Introduction: Clostridium (C perfringens and Klebsiella (K oxytoca are pathogenous human bacteria. Due to the production of several toxins C. perfringens is virulent by causing i.a. the necrotizing fasciitis, gas gangrene and hepatic abscess. K. oxytoca mostly causes infections of the respiratory and gastrointestinal tract. Presentation of case: We are presenting the case of a male patient at the age of 64, who suffered from nausea and progressive pain in the right upper abdomen. A computer tomography of the abdomen revealed a 7 × 5,6 cm sized entrapped air in liver segment VII. Later the patient developed a multiorgan failure. We then performed an explorative laparotomy. Intraoperatively it became clear that the liver was destructed presenting an open liver abscess (LA cavity of segment VII. The gallbladder was found inflamed. We successfully conducted the consistent debridement of segment VII and removed the gallbladder. Microbiological examination isolated C. perfringens and K. oxytoca. The patient survived undergoing antimicrobial and multimodal sepsis therapy. Discussion: The LA is a severe disease in surgery. In literature an overall mortality of 6–14% is described. Mostly bacterial infections of the biliary tract and the gallbladder are responsible for a LA. Abscesses with sepsis caused by both, C. perfringens and K. oxytoca, are highly perilous but rarely described in literature. Conclusion: When diagnosing an LA caused by C. perfringens an immediate surgical debridement and antimicrobial treatment is mandatory for the patient’s survival. Keywords: Liver abscess, Sepsis, Clostridium perfringens, Klebsiella oxytoca, Gas gangrene

  18. Diversity of Clostridium perfringens isolates from various sources and prevalence of conjugative plasmids.

    Science.gov (United States)

    Park, Miseon; Deck, Joanna; Foley, Steven L; Nayak, Rajesh; Songer, J Glenn; Seibel, Janice R; Khan, Saeed A; Rooney, Alejandro P; Hecht, David W; Rafii, Fatemeh

    2016-04-01

    Clostridium perfringens is an important pathogen, causing food poisoning and other mild to severe infections in humans and animals. Some strains of C. perfringens contain conjugative plasmids, which may carry antimicrobial resistance and toxin genes. We studied genomic and plasmid diversity of 145 C. perfringens type A strains isolated from soils, foods, chickens, clinical samples, and domestic animals (porcine, bovine and canine), from different geographic areas in the United States between 1994 and 2006, using multiple-locus variable-number tandem repeat analysis (MLVA) and/or pulsed-field gel electrophoresis (PFGE). MLVA detected the genetic diversity in a majority of the isolates. PFGE, using SmaI and KspI, confirmed the MLVA results but also detected differences among the strains that could not be differentiated by MLVA. All of the PFGE profiles of the strains were different, except for a few of the epidemiologically related strains, which were identical. The PFGE profiles of strains isolated from the same domestic animal species were clustered more closely with each other than with other strains. However, a variety of C. perfringens strains with distinct genetic backgrounds were found among the clinical isolates. Variation was also observed in the size and number of plasmids in the strains. Primers for the internal fragment of a conjugative tcpH gene of C. perfringens plasmid pCPF4969 amplified identical size fragments from a majority of strains tested; and this gene hybridized to the various-sized plasmids of these strains. The sequences of the PCR-amplified tcpH genes from 12 strains showed diversity among the tcpH genes. Regardless of the sources of the isolates, the genetic diversity of C. perfringens extended to the plasmids carrying conjugative genes. Published by Elsevier Ltd.

  19. GM1 erythroimmunoassay for detection and titration of Escherichia coli heat-labile enterotoxin.

    OpenAIRE

    Germani, Y; Bégaud, E; Guesdon, J L; Moreau, J P

    1986-01-01

    A GM1 ganglioside erythroimmunoassay for the detection of heat-labile Escherichia coli enterotoxin (LT) was developed for use in poorly equipped laboratories in developing countries. This assay is based on the immunological similarity between Vibrio cholerae toxin and LT and uses cholera toxin antiserum and sheep anti-rabbit immunoglobulin covalently coupled to sheep erythrocytes as conjugate. This assay has the following advantages over other currently available techniques: the reagents it u...

  20. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2011-05-08

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17β-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17β-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17β-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective permeabilization of apical or basolateral membranes with amphotericin B or nystatin was used to isolate basolateral K(+) channel and apical Cl(-) channel activity, respectively. 17β-Estradiol dose-dependently inhibited secretory responses to both toxins with IC(50) values of approximately 1nM. This effect was female-gender specific, with no inhibition observed in male tissues. 17β-Estradiol responses were insensitive to the pure anti-estrogen ICI 182,720. 17β-Estradiol exerted its effects downstream of enterotoxin-induced production of second messengers (cAMP and cGMP) but was dependent on PKCδ activation. In nystatin-permeabilized tissues, apical Cl(-) currents were unaffected by 17β-estradiol treatment while basolateral K(+) current was profoundly inhibited by the hormone. This current was sensitive to the specific KCNQ1 channel inhibitors chromanol 293B and HMR-1556. In conclusion, 17β-estradiol inhibits enterotoxin-induced Cl(-) secretion via a PKCδ-dependent mechanism involving inhibition of basolateral KCNQ1 channels. These data elucidate mechanisms of 17β-estradiol inhibition of Cl(-) secretion induced by enterotoxins in intestinal epithelia, which may be relevant for the treatment of diarrheal diseases.

  1. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2012-02-01

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17beta-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17beta-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17beta-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective permeabilization of apical or basolateral membranes with amphotericin B or nystatin was used to isolate basolateral K(+) channel and apical Cl(-) channel activity, respectively. 17beta-Estradiol dose-dependently inhibited secretory responses to both toxins with IC(50) values of approximately 1nM. This effect was female-gender specific, with no inhibition observed in male tissues. 17beta-Estradiol responses were insensitive to the pure anti-estrogen ICI 182,720. 17beta-Estradiol exerted its effects downstream of enterotoxin-induced production of second messengers (cAMP and cGMP) but was dependent on PKCdelta activation. In nystatin-permeabilized tissues, apical Cl(-) currents were unaffected by 17beta-estradiol treatment while basolateral K(+) current was profoundly inhibited by the hormone. This current was sensitive to the specific KCNQ1 channel inhibitors chromanol 293B and HMR-1556. In conclusion, 17beta-estradiol inhibits enterotoxin-induced Cl(-) secretion via a PKCdelta-dependent mechanism involving inhibition of basolateral KCNQ1 channels. These data elucidate mechanisms of 17beta-estradiol inhibition of Cl(-) secretion induced by enterotoxins in intestinal epithelia, which may be relevant for the treatment of diarrheal diseases.

  2. PCR detection of staphylococcal enterotoxin genes in Staphylococcus aureus strains isolated from raw and pasteurized milk.

    Science.gov (United States)

    Rall, V L M; Vieira, F P; Rall, R; Vieitis, R L; Fernandes, A; Candeias, J M G; Cardoso, K F G; Araújo, J P

    2008-12-10

    Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI and SEJ in S. aureus strains isolated from raw or pasteurized bovine milk. S. aureus was found in 38 (70.4%) out of 54 raw milk samples at concentrations of up to 8.9 x 10(5) CFU/ml. This microorganism was present in eight samples of pasteurized milk before the expiration date and in 11 samples analyzed on the expiration date. Of the 57 strains studied, 68.4% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene coding for enterotoxin A, sea, was the most frequent (16 strains, 41%), followed by sec (8 strains, 20.5%), sed (5 strains, 12.8%), seb (3 strains, 7.7%) and see (2 strains, 5.1%). Among the genes encoding the other enterotoxins, seg was the most frequently observed (11 strains, 28.2%), followed by sei (10 strains) and seh and sej (3 strains each). With the recent identification of new SEs, the perceived frequency of enterotoxigenic strains has increased, suggesting that the pathogenic potential of staphylococci may be higher than previously thought; however, further studies are required to assess the expression of these new SEs by S. aureus, and their impact in foodborne disease. The quality of Brazilian milk is still low, and efforts from the government and the entire productive chain are required to attain consumer safety.

  3. Antibiotic resistance and enterotoxin genes in Staphylococcus sp. isolates from polluted water in Southern Brazil

    OpenAIRE

    BASSO, ANA P.; MARTINS, PAULA D.; NACHTIGALL, GISELE; SAND, SUELI VAN DER; MOURA, TIANE M. DE; FRAZZON, ANA PAULA G.

    2014-01-01

    The aim of this study was to evaluate the species distribution, antibiotic-resistance profile and presence of enterotoxin (SE) genes in staphylococci isolated from the Dilúvio stream in South Brazil. Eighty-eight staphylococci were identified, 93.18% were identified as coagulase-negative (CNS) and 6.82% coagulase-positive (CPS). Fourteen Staphylococcus species were detected and the most frequently were Staphylococcus cohnii (30.48%) and S. haemolyticus (21.95%). Resistance to erythromycin was...

  4. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    OpenAIRE

    Alzamora, Rodrigo; O'Mahony, Fiona; Harvey, Brian J

    2011-01-01

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17β-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17β-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17β-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective per...

  5. A Single-Stranded DNA Aptamer That Selectively Binds to Staphylococcus aureus Enterotoxin B

    OpenAIRE

    DeGrasse, Jeffrey A.

    2012-01-01

    The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify s...

  6. Effects of frozen storage on survival of Staphylococcus aureus and enterotoxin production in precooked tuna meat.

    Science.gov (United States)

    Wu, Xulei; Su, Yi-Cheng

    2014-08-01

    This study investigated the survival of Staphylococcus aureus in precooked tuna meat for producing canned products during frozen storage (-20 ± 2 °C) as well as its growth and enterotoxin production at 35 to 37 °C after the storage. Samples (50 ± 5 g) of precooked albacore (loin, chunk, and flake) and skipjack (chunk and flake) tuna were inoculated with 5 enterotoxin-producing strains of S. aureus at a level of approximately 3.5 log CFU/g and individually packed in a vacuum bag after 3 h incubation at 35 to 37 °C. Vacuum-packed samples were stored in a freezer (-20 ± 2 °C) for 4 wk. The frozen samples were then thawed in 37 °C circulating water for 2 h and incubated at 35 to 37 °C for 22 h. Populations of S. aureus in all precooked tuna samples decreased slightly (canned tuna within 6 to 8 h of thawing to avoid product spoilage and potential enterotoxin production by S. aureus in contaminated precooked tuna meat. © 2014 Institute of Food Technologists®

  7. A rapid qualitative assay for detection of Clostridium perfringens in canned food products.

    Science.gov (United States)

    Dave, Gayatri Ashwinkumar

    2017-01-01

    Clostridium perfringens (MTCC 1349) is a Gram-positive, anaerobic, endospore forming, and rod-shaped bacterium. This bacterium produces a variety of toxins under strict anaerobic environment. C. perfringens can grow at temperatures ranging between 20°C and 50°C. It is the major causetive agent for gas gangrene, cellulitis, septicemia, necrotic enteritis and food poisoning, which are common toxin induced conditions noted in human and animals. C. perfringens can produce produce four major types of toxins that are used for the classification of strains, classified under type A-E. Across the globe many countries, including the United States, are affected by C. perfringens food poisonings where it is ranked as one of the most common causes of food borne infections. To date, no direct one step assay for the detection of C. perfringens has been developed and only few methods are known for accurate detection of C. perfringens. Long detection and incubation time is the major consideration of these reporter assays. The prensent study proposes a rapid and reliable colorimetric assay for the detection of C. perfringens. In principale, this assay detects the para nitrophenyl (yellow colour end product) liberated due to the hydrolysis of paranitrophenyl phosphetidyl choline (PNPC) through phospholipase C (lecithinase). Constitutive secretion of phospholipase C is a charactristic feature of C. perfringens. This assay detects the presence of the extracellular lecithinse through the PNPC impragnated impregnated probe. The probe is impregnated with peranitrophenyl phosphotidyl choline ester, which is colourless substrate used by lecithinase. The designed assay is specific towards PNPC and detectes very small quantites of lecithinase under conditions used. The reaction is substrate specific, no cross reaction was observed upon incubation with other substrates. In addition, this assay gave negative results with other clostridium strains, no cross reactions were observed with other

  8. Clostridium perfringens bacteremia caused by choledocholithiasis in the absence of gallbladder stones.

    Science.gov (United States)

    Atia, Antwan; Raiyani, Tejas; Patel, Pranav; Patton, Robert; Young, Mark

    2012-10-21

    A 67-years-old male presented with periumbilical abdominal pain, fever and jaundice. His anaerobic blood culture was positive for clostridium perfringens. Computed tomogram scan of the abdomen and abdominal ultrasound showed normal gallbladder and common bile duct (CBD). Subsequently magnetic resonance cholangiopancreaticogram showed choledocholithiasis. Endoscopic retrograde cholangiopancreaticogramwith sphincterotomy and CBD stone extraction was performed. The patient progressively improved with antibiotic therapy Choledocholithiasis should be considered as a source of clostridium perfringens bacteremia especially in the setting of elevated liver enzymes with cholestatic pattern.

  9. Staphylococcal superantigens; toxic shock syndrome toxin-1 and enterotoxins in pediatric otitis media effusion: a brief report

    Directory of Open Access Journals (Sweden)

    Noorbakhsh S

    2013-03-01

    Full Text Available Background: Staphylococcal superantigens (SAg's may have some role in otitis media with effusion (OME. The aim of this study was the search of staphylococcal SAg's in middle ear effusion of children with OME.  Methods: This cross sectional-analytic study was done in ENT & pediatric wards upon 64 children with otitis media with effusion (OME between 1-15 years, (mean age=7.42+4 years of Rasoul Akram University Hospital, Tehran, Iran in 2009-2011. Fifty six percent (36 of cases were male, 43.8% (28 were female. Staphylococcal SAg's; Toxic Shock Syndrome Toxin-1 (TSST-1, Staphylococcal enterotoxin A, B, C, D (Enzyme immune assay, AB Cam, USA were detected in middle ear effusion samples after conventional culture.Results: None type of SAg's found in 39% of OME cases, enterotoxin B found in: 22%; enterotoxin A: 17%, enterotoxin C: 15.6%, enterotoxin D: 12.5%, Toxic Shock Syndrome Toxin-1 (TSST-1: 7.8% Mean age of cases with positive TSST-1, enterotoxin A, B, C, and D was: 1, 5, 8.6, 9.6 and 9.6 years respectively. Positive TSST had no agreement with positive enterotoxin A and C but had weak agreement with type B and D. Mean age of cases with positive TSST was one years which had significant difference with (7.9 years in cases with negative TSST test (P<0.0001.Conclusion: At least one or more type of staphylococcal toxins had found in middle ear effusion of 70% of OME cases with negative culture for Staphylococcus aureus. Even in culture negative cases, staphylococcal toxins might have some immunologic role in middle ear effusion forming. Finding the SAg's (at least one type are important for treatment of immunosuppressive or corticosteroid in cases with resistant OME.

  10. Speciative Determination of Dissolved Inorganic Fe(II), Fe(III) and Total Fe in Natural Waters by Coupling CPE with FAAS

    International Nuclear Information System (INIS)

    Gurkan, R.; Altunay, N.

    2013-01-01

    A new cloud point extraction (CPE) method for the preconcentration of trace iron speciation in natural waters prior to determination by flame atomic absorption spectrometry (FAAS) was developed in the present study. In this method, Fe(II) sensitively and selectively reacts with Calcon carboxylic acid (CCA) in presence of cetylpyridinium chloride (CPC) yielding a hydrophobic complex at pH 10.5, which is then entrapped in surfactant-rich phase. Total Fe was accurately and reliably determined after the reduction of Fe(III) to Fe(II) with sulfite. The amount of Fe(III) in samples was determined from the difference between total Fe and Fe(II). CPC was used not only as an auxiliary ligand in CPE, but also as sensitivity enhancement agent in FAAS. The nonionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent. The analytical variables affecting CPE efficiency were investigated in detail. The preconcentration/enhancement factors of 50 and 82 respectively, were obtained for the preconcentration of Fe(II) with 50 mL solution. Under the optimized conditions, the detection limit of Fe(II) in linear range of 0.2-60 μg L/sup -1/ was 0.06 μg L/sup -1/. The relative standard deviation was 2.7 percentage (20 μg L/sup -1/, N: 5), recoveries for Fe(II) were in range of 99.0-102.0 percentage for all water samples including certified reference materials (CRMs). In order to verify its accuracy, two CRMs were analyzed and the results obtained were statistically in good agreement with the certified values. (author)

  11. Quantitative analyses of regional [{sup 11}C]PE2I binding to the dopamine transporter in the human brain: a PET study

    Energy Technology Data Exchange (ETDEWEB)

    Jucaite, Aurelija [Karolinska Institutet, Department of Woman and Child Health, Stockholm (Sweden); Odano, Ikuo [Niigata University, Department of Sensory and Integrative Medicine, Asahimachi-dori Niigata (Japan); Olsson, Hans; Pauli, Stefan; Halldin, Christer; Farde, Lars [Karolinska Institutet, Psychiatry Section, Department of Clinical Neuroscience, Stockholm (Sweden)

    2006-06-15

    The dopamine transporter (DAT) is a plasma membrane protein of central interest in the pathophysiology of neuropsychiatric disorders and is known to be a target for psychostimulant drugs. [{sup 11}C]PE2I is a new radioligand which binds selectively and with moderate affinity to central DAT, as has been demonstrated in vitro by autoradiography and in vivo by positron emission tomography (PET). The aims of the present PET study were to quantify regional [{sup 11}C]PE2I binding to DAT in the human brain and to compare quantitative methods with regard to suitability for applied clinical studies. One PET measurement was performed in each of eight healthy male subjects. The binding potential (BP) values were obtained by applying kinetic compartment analysis, which uses the metabolite-corrected arterial plasma curve as an input function. They were compared with the BP values quantified by two reference tissue approaches, using cerebellum as a reference region representing free and non-specific radioligand binding. The radioactivity concentration was highest in the striatum, lower in the midbrain and very low in the cerebellum. The regional [{sup 11}C]PE2I binding could be interpreted by kinetic compartment models. However, the BP values in the striatum obtained by the compartment analyses were about 30% higher than the BP values obtained using reference tissue methods. We suggest that the difference may be explained by the inaccurate metabolite correction, small amounts of radioactive metabolites that could account for the presence of non-specific binding in the cerebellum and insufficient data acquisition time. (orig.)

  12. Strong ion exchange in centrifugal partition extraction (SIX-CPE): effect of partition cell design and dimensions on purification process efficiency.

    Science.gov (United States)

    Hamzaoui, Mahmoud; Hubert, Jane; Reynaud, Romain; Marchal, Luc; Foucault, Alain; Renault, Jean-Hugues

    2012-07-20

    The aim of this article was to evaluate the influence of the column design of a hydrostatic support-free liquid-liquid chromatography device on the process efficiency when the strong ion-exchange (SIX) development mode is used. The purification of p-hydroxybenzylglucosinolate (sinalbin) from a crude aqueous extract of white mustard seeds (Sinapis alba L.) was achieved on two types of devices: a centrifugal partition chromatograph (CPC) and a centrifugal partition extractor (CPE). They differ in the number, volume and geometry of their partition cells. The SIX-CPE process was evaluated in terms of productivity and sinalbin purification capability as compared to previously optimized SIX-CPC protocols that were carried out on columns of 200 mL and 5700 mL inner volume, respectively. The objective was to determine whether the decrease in partition cell number, the increase in their volume and the use of a "twin cell" design would induce a significant increase in productivity by applying higher mobile phase flow rate while maintaining a constant separation quality. 4.6g of sinalbin (92% recovery) were isolated from 25 g of a crude white mustard seed extract, in only 32 min and with a purity of 94.7%, thus corresponding to a productivity of 28 g per hour and per liter of column volume (g/h/LV(c)). Therefore, the SIX-CPE process demonstrates promising industrial technology transfer perspectives for the large-scale isolation of ionized natural products. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Enteric Diseases of Poultry with Special Attention to Clostridium perfringens

    Directory of Open Access Journals (Sweden)

    Hafez Mohamed Hafez

    2011-06-01

    Full Text Available The enteric heath of growing poultry is imperative to success of the production. The basic role of poultry production is turning feed stuffs into meat. Any changes in this turning process, due to mechanical, chemical or biological disturbance of digestive system (enteric disorders is mostly accompanied with high economic losses due to poor performance, increased mortality rates and increased medication costs. The severity of clinical signs and course of the disorders are influenced several factors such as management, nutrition and the involved agent(s. Several pathogens (viruses, bacteria and parasites are incriminated as possible cause of enteric disorders either alone (mono-causal, in synergy with other micro-organisms (multi-causal, or with non-infectious causes such as feed and /or management related factors. In addition, excessive levels of mycotoxins and biogenic amines in feed lead to enteric disorders. Also factors such as high stocking density, poor litter conditions, poor hygiene and high ammonia level and other stressful situation may reduce the resistance of the birds and increases their susceptibility to infections. Under field conditions, however, under filed conditions it is difficult to determine whether the true cause of enteric disorders, is of infectious or non-infectious origin. In recent years and since the ban of use of antimicrobial growth promoters in several countries the incidence of intestinal disorders especially those caused by clostridial infection was drastically increased. The present review described in general the several factors involved in enteric disorders and summarized the available literatures about Clostridium perfringens infection in poultry.

  14. Necrotizing Enterocolitis in Preterm Pigs Is Associated with Increased Density of Intestinal Mucosa-Associated Bacteria Including Clostridium perfringens

    DEFF Research Database (Denmark)

    Støy, Ann Cathrine Findal; Mølbak, Lars; Delègue, Camilla Lindholm

    2015-01-01

    correlates with NEC severity in preterm pigs and that in vitro infection with increasing densities of Clostridium perfringens, which has been associated with NEC in preterm infants, would lead to a transcriptional response related to the inflammatory conditions of NEC. Methods: First, we determined...... the density of total bacteria and C. perfringens in the distal small intestinal mucosa of 58 NEC and healthy preterm pigs using quantitative PCR. Next, we analyzed in IPEC-J2 cells the effect of different infection densities of C. perfringens type A on the expression of genes related to intestinal function...

  15. Genome-wide transcriptional profiling of Clostridium perfringens SM101 during sporulation

    NARCIS (Netherlands)

    Xiao, Yinghua; Hijum, van Sacha A.; Abee, Tjakko; Wells-Bennik, Marjon H.

    2014-01-01

    In this study we focus on the identification of new genes tentatively involved in sporulation and those that influence properties of spores and their ability to germinate. To this end, the sporulation stages of C. perfringens enterotoxic strain SM101 were characterized based on morphological

  16. Occurrence of Beta2 toxigenic Clostridium perfringens isolates with different toxin types in Iran

    Directory of Open Access Journals (Sweden)

    Jabbari, A.R.

    2012-11-01

    Full Text Available Clostridium perfringens is an important cause of enteric diseases in both human and animals. The bacteria produce several toxins which play key roles in the pathogenesis of diseases and are classified into five toxin types, on the basis of the differential production of Alpha, Beta, Epsilon and Iota toxins. In this study a single PCR assay was developed and used for detection of cpb2 gene to identify the Beta2 harboring isolates among different types of C. perfringens isolated from animal enteric diseases in Iran. It was found that cpb2 presents among C. perfringens isolates types A, B, C and D with 54.5% (6/11, 62% (13/21, 42.8% (6/14, 69.25% (9/13, respectively. Totally 34 of 59 (56.7% isolates screened by PCR were cpb2-positive. This is the first report of cpb2 positive isolates of C. perfringens causing enteric diseases of animals in Iran. Further studies to demonstrate the exact role of Beta2 toxin in pathogenesis of the bacterium is suggested.

  17. Clostridium perfringens infection complicating periprosthetic fracture fixation about the hip: successful treatment with early aggressive debridement.

    LENUS (Irish Health Repository)

    Baker, Joseph F

    2012-07-13

    Periprosthetic fracture and infection are both challenges following hip arthroplasty. We report the case of an 87 year old female who underwent open reduction and internal fixation of a periprosthetic femoral fracture. Her post-operative course was complicated by infection with Clostridium perfringens. Early aggressive antibiotic treatment and surgical debridement were successful, and allowed retention of the original components.

  18. Clostridium perfringens bacteremia caused by choledocholithiasis in the absence of gallbladder stones

    OpenAIRE

    Atia, Antwan; Raiyani, Tejas; Patel, Pranav; Patton, Robert; Young, Mark

    2012-01-01

    A 67-years-old male presented with periumbilical abdominal pain, fever and jaundice. His anaerobic blood culture was positive for clostridium perfringens. Computed tomogram scan of the abdomen and abdominal ultrasound showed normal gallbladder and common bile duct (CBD). Subsequently magnetic resonance cholangiopancreaticogram showed choledocholithiasis. Endoscopic retrograde cholangiopancreaticogramwith sphincterotomy and CBD stone extraction was performed. The patient progressively improved...

  19. In vitro Clostridium perfringens and Escherichia coli toxin adsorption of Varium

    Science.gov (United States)

    Enteric disease agents, such as Clostridium perfringens and Escherichia coli, produce detrimental biotoxins that cause significant economic loss annually in the poultry industry. The objective of this study was to determine the in vitro biotoxin adsorption capability of Varium. An enzyme-linked im...

  20. Lipoproteins from Clostridium perfringens and their protective efficacy in mouse model.

    Science.gov (United States)

    Dwivedi, Pratistha; Alam, Syed Imteyaz; Kumar, Om; Kumar, Ravi Bhushan

    2015-08-01

    Clostridium perfringens is an obligately anaerobic rod-shaped bacterium and etiological agent for several diseases in humans and animals. The pathogen has been listed as Validated Biological Agent and warrants development of medical countermeasures. The homologs of some of the lipoproteins identified from various fractions of C. perfringens in our previous studies were observed to be virulence determinants in other pathogenic bacteria. Three putative virulence associated lipoproteins; polysaccharide deacetylase family protein, probable ion-uptake ABC transporter, and a putative lipoprotein of no known function are reported here with respect to their immuno-protective potentials. The three proteins were over expressed and purified to near homogeneity. The lipoproteins were shown to be exposed on the C. perfringens surface and, hence, accessible to antibodies and potentially visible to the host immune system. Immunization of mice with purified recombinant proteins elicited protective immunity against challenge with C. perfringens in mouse gas gangrene model. Distribution and relationship of orthologous proteins across other bacterial select agents especially among the members of Firmicutes, was carried out to look for conserved antigenic determinants. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Inhibition of Binding of the AB5-Type Enterotoxins LT-I and Cholera Toxin to Ganglioside GM1 by Galactose-Rich Dietary Components

    NARCIS (Netherlands)

    Becker, P.M.; Widjaja-Greefkes, H.C.A.; Wikselaar, van P.G.

    2010-01-01

    Cholera, travelers' diarrhea, or colibacillosis in pigs can possibly be prevented or attenuated by dietary provision of competitive inhibitors that react with the GM1-binding sites of the enterotoxins cholera toxin (CT), human Escherichia coli heat-labile enterotoxin of serogroup I (LTh-I), and

  2. The Role of Clostridium Perfringens in the Syndrome of Intestinal Affection in Children and Possibilities of Drug Correction

    Directory of Open Access Journals (Sweden)

    G.O. Lezhenko

    2014-09-01

    Full Text Available The article showed the features of clostridiosis course, caused by Clostridium perfringens, in children of different age groups taking into account the dose of pathogen in feces and pathogenetically grounded possibilities of etiological therapy.

  3. Detection of Clostridium perfringens in yearling lamb meat (barbacoa), head, and gut tacos from public markets in Mexico City.

    Science.gov (United States)

    Natividad-Bonifacio, Iván; Vázquez-Quiñones, Carlos R; Rodas-Suárez, Oscar R; Fernández, Francisco J; Rodríguez-Solis, Esteban; Quiñones-Ramírez, Elsa Irma; Vázquez-Salinas, Carlos

    2010-06-01

    No reports on the incidence of Clostridium perfringens in popularly-consumed food from Mexico City have been published; neither are there any reports that have analyzed food consumed in popular markets and less established restaurants. Therefore, this study is aimed at providing data to evaluate the relevance of C. perfringens as an etiologic agent of food-borne diseases. Of the 650 analyzed samples, 106 (16.3%) were positive for C. perfringens; 6.4% (16/250) isolates were from barbacoa, 19% (38/200) from head, and 13% (52/200) from gut tacos. The presence of C. perfringens in these popular-consumed foods demonstrates its relevance as an etiologic agent of food-borne diseases, and confirms the great sanitary risk involved in their consumption. These results may serve as a basis for the Mexican sanitary authorities to control the microbiological quality of street-made foods.

  4. The impact of various browse feeds with different tannin content on the fecal shedding of Clostridium perfringens in West African dwarf sheep.

    Science.gov (United States)

    Aschfalk, A; Müller, W; Drochner, W

    2000-01-01

    In 1994 and 1995 leaves from eight browse feeds, containing tannins in different amounts (BF), were fed to West African Dwarf Sheep in Benin to evaluate their impact on Clostridium perfringens in the intestinal tract. An inhibitory impact of various BF on the growth of C. perfringens was assessed in in-vitro assays before, and thus a potential use of these leaves as a preventive diet against C. perfringens enterotoxemia in small ruminants was assumed. Surprisingly, an inhibitory impact of the BF on the shedding of C. perfringens in the feces of West African Dwarf Sheep could not be shown in seven of the eight BF examined. However, the pattern of inhibition of unlike C. perfringens toxovars may differ and a selective inhibitory impact of the BF Dialium guineense on C. perfringens toxovar D may be assumed.

  5. How do the rotavirus NSP4 and bacterial enterotoxins lead differently to diarrhea?

    Directory of Open Access Journals (Sweden)

    Vasseur Monique

    2007-03-01

    Full Text Available Abstract Rotavirus is the major cause of infantile gastroenteritis and each year causes 611 000 deaths worldwide. The virus infects the mature enterocytes of the villus tip of the small intestine and induces a watery diarrhea. Diarrhea can occur with no visible tissue damage and, conversely, the histological lesions can be asymptomatic. Rotavirus impairs activities of intestinal disaccharidases and Na+-solute symports coupled with water transport. Maldigestion of carbohydrates and their accumulation in the intestinal lumen as well as malabsorption of nutrients and a concomitant inhibition of water reabsorption can lead to a malabsorption component of diarrhea. Since the discovery of the NSP4 enterotoxin, diverse hypotheses have been proposed in favor of an additional secretion component in the pathogenesis of diarrhea. Rotavirus induces a moderate net chloride secretion at the onset of diarrhea, but the mechanisms appear to be quite different from those used by bacterial enterotoxins that cause pure secretory diarrhea. Rotavirus failed to stimulate Cl- secretion in crypt, whereas it stimulated Cl- reabsorption in villi, questioning, therefore, the origin of net Cl- secretion. A solution to this riddle was that intestinal villi do in fact secrete chloride as a result of rotavirus infection. Also, the overall chloride secretory response is regulated by a phospholipase C-dependent calcium signaling pathway induced by NSP4. However, the overall response is weak, suggesting that NSP4 may exert both secretory and subsequent anti-secretory actions, as did carbachol, hence limiting Cl- secretion. All these characteristics provide the means to make the necessary functional distinction between viral NSP4 and bacterial enterotoxins.

  6. NetB, a new toxin that is associated with avian necrotic enteritis caused by Clostridium perfringens.

    Directory of Open Access Journals (Sweden)

    Anthony L Keyburn

    2008-02-01

    Full Text Available For over 30 years a phospholipase C enzyme called alpha-toxin was thought to be the key virulence factor in necrotic enteritis caused by Clostridium perfringens. However, using a gene knockout mutant we have recently shown that alpha-toxin is not essential for pathogenesis. We have now discovered a key virulence determinant. A novel toxin (NetB was identified in a C. perfringens strain isolated from a chicken suffering from necrotic enteritis (NE. The toxin displayed limited amino acid sequence similarity to several pore forming toxins including beta-toxin from C. perfringens (38% identity and alpha-toxin from Staphylococcus aureus (31% identity. NetB was only identified in C. perfringens type A strains isolated from chickens suffering NE. Both purified native NetB and recombinant NetB displayed cytotoxic activity against the chicken leghorn male hepatoma cell line LMH; inducing cell rounding and lysis. To determine the role of NetB in NE a netB mutant of a virulent C. perfringens chicken isolate was constructed by homologous recombination, and its virulence assessed in a chicken disease model. The netB mutant was unable to cause disease whereas the wild-type parent strain and the netB mutant complemented with a wild-type netB gene caused significant levels of NE. These data show unequivocally that in this isolate a functional NetB toxin is critical for the ability of C. perfringens to cause NE in chickens. This novel toxin is the first definitive virulence factor to be identified in avian C. perfringens strains capable of causing NE. Furthermore, the netB mutant is the first rationally attenuated strain obtained in an NE-causing isolate of C. perfringens; as such it has considerable vaccine potential.

  7. Uncoupling of T Cell Receptor Zeta Chain Function during the Induction of Anergy by the Superantigen, Staphylococcal Enterotoxin A

    Directory of Open Access Journals (Sweden)

    William D. Cornwell

    2010-06-01

    Full Text Available Staphylococcus aureus enterotoxins have immunomodulatory properties. In this study, we show that Staphylococcal enterotoxin A (SEA induces a strong proliferative response in a murine T cell clone independent of MHC class II bearing cells. SEA stimulation also induces a state of hypo-responsiveness (anergy. We characterized the components of the T cell receptor (TCR during induction of anergy by SEA. Most interestingly, TCR zeta chain phosphorylation was absent under SEA anergizing conditions, which suggests an uncoupling of zeta chain function. We characterize here a model system for studying anergy in the absence of confounding costimulatory signals.

  8. Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo

    OpenAIRE

    Lv, You; Ye, Tao; Wang, Hui-Peng; Zhao, Jia-Ying; Chen, Wen-Jie; Wang, Xin; Shen, Chen-Xia; Wu, Yi-Bin; Cai, Yuan-Kun

    2017-01-01

    AIM To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). METHODS Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dos...

  9. An Enterotoxin-Like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity.

    Science.gov (United States)

    Wei, Jun-Zhi; Siehl, Daniel L; Hou, Zhenglin; Rosen, Barbara; Oral, Jarred; Taylor, Christopher G; Wu, Gusui

    2017-10-01

    Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic Pseudomonas protegens strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated Pp-ANP, which is responsible for the nematicidal activity. This binary protein inhibits Caenorhabditis elegans growth and development by arresting larvae at the L1 stage and killing older-staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a, are active when reconstituted from separate expression in Escherichia coli The binary toxin also shows strong nematicidal activity against three other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.), but we did not find any activity against insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant identity to any known proteins, while Pp-ANP2a shows ∼30% identity to E. coli heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates that Pp-ANP2a is structurally similar to CT/LT and likely acts as an ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggest applications in controlling parasitic nematodes and open an avenue for further research on its mechanism of action and role in bacterium-nematode interaction. IMPORTANCE This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP, from a Pseudomonas protegens strain. Pp-ANP shows strong nematicidal activity against Caenorhabditis elegans larvae and older-staged worms. It also shows strong activity on other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and

  10. Plant-Derived Polyphenols Interact with Staphylococcal Enterotoxin A and Inhibit Toxin Activity

    OpenAIRE

    Shimamura, Yuko; Aoki, Natsumi; Sugiyama, Yuka; Tanaka, Takashi; Murata, Masatsune; Masuda, Shuichi

    2016-01-01

    This study was performed to investigate the inhibitory effects of 16 different plant-derived polyphenols on the toxicity of staphylococcal enterotoxin A (SEA). Plant-derived polyphenols were incubated with the cultured Staphylococcus aureus C-29 to investigate the effects of these samples on SEA produced from C-29 using Western blot analysis. Twelve polyphenols (0.1-0.5 mg/mL) inhibited the interaction between the anti-SEA antibody and SEA. We examined whether the polyphenols could directly i...

  11. Molecular Characterization of Enterotoxin-Producing Escherichia coli Collected in 2011-2012, Russia.

    Directory of Open Access Journals (Sweden)

    Nikolay N Kartsev

    Full Text Available Enterotoxin-producing Escherichia coli (ETEC are one of the main causative agents of diarrhea in children especially in developing countries and travel diarrhoea in adults. Pathogenic properties of ETEC associated with their ability to produce a heat-stable (ST and/or heat-labile (LT enterotoxins, as well as adhesins providing bacterial adhesion to intestinal epithelial cells. This study presents the molecular characterization of the ETEC isolates collected from the Central and Far-Eastern regions of Russia in 2011-2012. It was shown that all ETEC under study (n=18 had the heat-labile enterotoxin-coding operon elt, and had no the genes of the heat-stable enterotoxin operon est. DNA sequencing revealed two types of nucleotide exchanges in the eltB gene coding subunit B of LT in isolates collected from Cherepovets city (Central region, Russia and Vladivostok city (Far-East region, Russia. Only one ETEC strain carried genes cfaA, cfaB, cfaC and cfaD coding adhesion factor CFA/I. Expression of LT in four ETEC isolates in the agglutination reaction was detected using a latex test-system. The isolates were assigned to serogroups O142 (n = 6, О6 (n = 4, О25 (n = 5, О26 (n = 2, and O115 (n = 1. Genotyping showed that they belonged to an earlier described sequence-type ST4 (n = 3 as well as to 11 novel sequence-types ST1043, ST1312, ST3697, ST3707, ST3708, ST3709, ST3710, ST3755, ST3756, ST3757 and ST4509. The ETEC isolates displayed different levels of antimicrobial resistance. Eight isolates were resistant to only one drug, three isolates-to two drugs, one isolate-to three drugs, two isolates-to four antibacterials, and only one isolate to each of the five, six and ten antibacterials simultaneously. Genetic determinants of the resistance to beta-lactams and other classes of antibacterials on the ETEC genomes were identified. There are blaTEM (n = 10, blaCTX-M-15 (n = 1, class 1 integron (n = 3 carrying resistance cassettes to aminoglycosides and

  12. Cloning Sequencing and Structural Manipulation of the Enterotoxin D and E Genes from Staphylococcus aureus

    Science.gov (United States)

    1990-07-01

    Iandolo, J.J. and R.K. Tweten. 1988. Purification of staphylococcal enterotoxin. In. Methods of Enzymology, (N.O. Kaplan , S. Harshman, Eds.) volume 165...N C V 9 L G 0 K 1 S P A K I C T S N 0 149 "T7AACTGG&&C&hICG&clhht:7caflCATGTAATAa~aI ACca CAACaCAA 942 L K D G D K L Z L I G T P r D H K V N 0 H L..L

  13. Elevated Enterotoxin A Expression and Formation in Staphylococcus aureus and Its Association with Prophage Induction

    OpenAIRE

    Cao, Rong; Zeaki, Nikoleta; Wallin-Carlquist, Nina; Skandamis, Panagiotis N.; Schelin, Jenny; Rådström, Peter

    2012-01-01

    Staphylococcus aureus strains producing the bacteriophage-encoded staphylococcal enterotoxin A (SEA) were divided into two groups, high- and low-SEA-producing strains, based on the amount of SEA produced. After growth under favorable conditions in batch cultures, 10 of the 21 strains tested produced more than 1,000 ng/ml SEA, and 9 strains produced less than 10 ng/ml SEA; two enterotoxigenic strains, MRSA252 and Newman, produced intermediate levels of SEA (around 450 ng/ml). The differences i...

  14. Molecular Characterization of Enterotoxin-Producing Escherichia coli Collected in 2011-2012, Russia.

    Science.gov (United States)

    Kartsev, Nikolay N; Fursova, Nadezhda K; Pachkunov, Dmitry M; Bannov, Vasiliy A; Eruslanov, Boris V; Svetoch, Edward A; Dyatlov, Ivan A

    2015-01-01

    Enterotoxin-producing Escherichia coli (ETEC) are one of the main causative agents of diarrhea in children especially in developing countries and travel diarrhoea in adults. Pathogenic properties of ETEC associated with their ability to produce a heat-stable (ST) and/or heat-labile (LT) enterotoxins, as well as adhesins providing bacterial adhesion to intestinal epithelial cells. This study presents the molecular characterization of the ETEC isolates collected from the Central and Far-Eastern regions of Russia in 2011-2012. It was shown that all ETEC under study (n=18) had the heat-labile enterotoxin-coding operon elt, and had no the genes of the heat-stable enterotoxin operon est. DNA sequencing revealed two types of nucleotide exchanges in the eltB gene coding subunit B of LT in isolates collected from Cherepovets city (Central region, Russia) and Vladivostok city (Far-East region, Russia). Only one ETEC strain carried genes cfaA, cfaB, cfaC and cfaD coding adhesion factor CFA/I. Expression of LT in four ETEC isolates in the agglutination reaction was detected using a latex test-system. The isolates were assigned to serogroups O142 (n = 6), О6 (n = 4), О25 (n = 5), О26 (n = 2), and O115 (n = 1). Genotyping showed that they belonged to an earlier described sequence-type ST4 (n = 3) as well as to 11 novel sequence-types ST1043, ST1312, ST3697, ST3707, ST3708, ST3709, ST3710, ST3755, ST3756, ST3757 and ST4509. The ETEC isolates displayed different levels of antimicrobial resistance. Eight isolates were resistant to only one drug, three isolates-to two drugs, one isolate-to three drugs, two isolates-to four antibacterials, and only one isolate to each of the five, six and ten antibacterials simultaneously. Genetic determinants of the resistance to beta-lactams and other classes of antibacterials on the ETEC genomes were identified. There are blaTEM (n = 10), blaCTX-M-15 (n = 1), class 1 integron (n = 3) carrying resistance cassettes to aminoglycosides and

  15. Experimental induction of abdominal tympany, abomasitis, and abomasal ulceration by intraruminal inoculation of Clostridium perfringens type A in neonatal calves.

    Science.gov (United States)

    Roeder, B L; Chengappa, M M; Nagaraja, T G; Avery, T B; Kennedy, G A

    1988-02-01

    The etiologic role of Clostridum perfringens type A in the acute abdominal syndrome characterized by abomasal and rumen tympany, abomasitis, and abomasal ulceration was investigated in neonatal calves. Eight calves, 4 to 12 days old, were inoculated intraruminally with toxigenic C perfringens type A. Before and after C perfringens inoculation, blood samples were collected from all calves for blood gas and serum biochemical analysis and for determination of serum copper concentration; ruminal fluid was obtained for isolation of C perfringens. Calves were monitored daily for clinical signs of the syndrome and, depending on the severity of clinical signs, they were either euthanatized or redosed within 4 to 7 days. After necropsy, specimens obtained from the abomasum and rumen for macroscopic and microscopic examination and for anaerobic bacteriologic culture were processed in routine manner. Intraruminal inoculation of C perfringens type A into healthy calves induced anorexia, depression, bloat, diarrhea, and in some calves, death. Serum copper concentration was within normal range. Necropsy revealed variable degrees of abomasitis, petechial and ecchymotic hemorrhages, and ulcers (ranging from pinpoint to nearly perforate) in the abomasum. Seven of those calves also had multiple trichobezoars in the rumen. These necropsy findings were not seen in calves (controls) given distilled H2O only. In affected calves, acute abdominal syndrome was unrelated to copper deficiency, and C perfringens type A given intraruminally was able to induce clinical signs similar to those of the naturally acquired disease.

  16. Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth.

    Science.gov (United States)

    Walker-York-Moore, Laura; Moore, Sean C; Fox, Edward M

    2017-07-15

    Bacillus cereus sensu lato species, as well as Staphylococcus aureus , are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA , hblA and entFM toxin genes, with lower prevalence of bceT and hlyII . When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log 10 (CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.

  17. Role of Enterotoxin-Producing Staphylococci in Zoonotic Infections in Iran

    Directory of Open Access Journals (Sweden)

    Abdolmajid Ghasemian

    2018-05-01

    Full Text Available Context: Staphylococci spp, are enterotoxin-producing zoonotic agents causing a variety of infections such as mastitis in animals and wound bite infections in humans. This review was conducted to determine the prevalence of Staphylococci infections especially to uncover enterotoxin-producing species in Iran. Evidence acquisition: for this review, words of "Staphylococcus", "zoonotic", "prevalence", "animals", "human" and "Iran" were searched in the internet engines such as Google Scholar, PubMed, Google, Science Direct and so on. Patients with no history of contact with animals were also included in the study for comparison aims. Both veterinary and human coagulase positive isolates were included. Data was analyzed with Graph Pad Prism 6, meta-analysis section. A total of 20 previous studies (450 clinical samples were found. S. intermedius was the predominant isolate identified in veterinary sources. Other coagulase positive spp such as S. hycus and S. simulans were isolated with lower prevalence, but S. delphini has not been detected. Conclusion: S. intermedius was the most isolate identified in veterinary sources with potential of causing infections in humans. Other coagulase positive spp such as S. hycus and S. simulans were isolated with lower prevalence, but S. delphini was not detected.

  18. Detection of enterotoxins and genotyping of Staphylococcus aureus strains isolated from Isfahan Educational Hospital, Iran

    Directory of Open Access Journals (Sweden)

    Seyed Asghar Havaei

    2017-10-01

    Full Text Available Background and aims: Staphylococcus aureus is known as one of the most important nosocomial pathogens, which may lead to several infections. The aim of this study was determining the enterotoxins A, C, and TSST-1 and molecular characterization of S. aureus strains with PFGE and MLST typing methods. Materials and methods: In the present study during the sixmonths sampling, fifty S. aureus strains were isolated from patients admitted to Al-Zahra university hospital. Antimicrobial susceptibility testing, Multiplex PCR for detection of enterotoxin A, C and TSST-1, pulse field gel electrophoresis (PFGE and multilocus sequence typing (MLST were used for molecular typing. Results: In antibiogram the highest and lowest percentage of resistance was belonged to tetracycline and rifampin respectively. Multiplex PCR indicated that 30% of the strains harbored sea and 34% harbored sec genes. However, only 4% of our collected isolates had tsst gene. In PFGE method analysis on all S. aureus strains, a total of 19 different patterns were identified. Nine various sequence types in 27 selected S. aureus isolates were identified by MLST. Conclusions: Present study indicates a possible higher variability among our S. aureus strains by two different molecular typing methods; nevertheless four main common types (CT1, CT7, CT9, and CT11 with at least one toxin genes were determined.

  19. Antibiotic resistance and enterotoxin genes in Staphylococcus sp. isolates from polluted water in Southern Brazil.

    Science.gov (United States)

    Basso, Ana P; Martins, Paula D; Nachtigall, Gisele; Van Der Sand, Sueli; De Moura, Tiane M; Frazzon, Ana Paula G

    2014-12-01

    The aim of this study was to evaluate the species distribution, antibiotic-resistance profile and presence of enterotoxin (SE) genes in staphylococci isolated from the Dilúvio stream in South Brazil. Eighty-eight staphylococci were identified, 93.18% were identified as coagulase-negative (CNS) and 6.82% coagulase-positive (CPS). Fourteen Staphylococcus species were detected and the most frequently were Staphylococcus cohnii (30.48%) and S. haemolyticus (21.95%). Resistance to erythromycin was verified in 37.50% of the strains, followed by 27.27% to penicillin, 12.50% to clindamycin, 6.81% to trimethoprim-sulfamethoxazole, 5.68% to chloramphenicol and 2.27% to norfloxacin. None of the investigated strains showed gentamicin and ciprofloxacin resistance. The strains were tested for the presence of sea, seb, sec, sed and see genes by PCR and only CNS strains (43.18%) showed positive results to one or more SE genes. The scientific importance of our results is due to the lack of data about these topics in polluted waters in Brazil. In conclusion, polluted waters from the Dilúvio stream may constitute a reservoir for disseminating antibiotic-resistance and enterotoxin into the community. In addition, the detection of staphylococci in the polluted waters of the Dilúvio stream indicated a situation of environmental contamination and poor sanitation conditions.

  20. Antibiotic resistance and enterotoxin genes in Staphylococcus sp. isolates from polluted water in Southern Brazil

    Directory of Open Access Journals (Sweden)

    ANA P. BASSO

    2014-12-01

    Full Text Available The aim of this study was to evaluate the species distribution, antibiotic-resistance profile and presence of enterotoxin (SE genes in staphylococci isolated from the Dilúvio stream in South Brazil. Eighty-eight staphylococci were identified, 93.18% were identified as coagulase-negative (CNS and 6.82% coagulase-positive (CPS. Fourteen Staphylococcus species were detected and the most frequently were Staphylococcus cohnii (30.48% and S. haemolyticus (21.95%. Resistance to erythromycin was verified in 37.50% of the strains, followed by 27.27% to penicillin, 12.50% to clindamycin, 6.81% to trimethoprim-sulfamethoxazole, 5.68% to chloramphenicol and 2.27% to norfloxacin. None of the investigated strains showed gentamicin and ciprofloxacin resistance. The strains were tested for the presence of sea, seb, sec, sed and see genes by PCR and only CNS strains (43.18% showed positive results to one or more SE genes. The scientific importance of our results is due to the lack of data about these topics in polluted waters in Brazil. In conclusion, polluted waters from the Dilúvio stream may constitute a reservoir for disseminating antibiotic-resistance and enterotoxin into the community. In addition, the detection of staphylococci in the polluted waters of the Dilúvio stream indicated a situation of environmental contamination and poor sanitation conditions.

  1. Staphylococcal enterotoxins in the Etiopathogenesis of Mucosal Autoimmunity within the Gastrointestinal Tract

    Directory of Open Access Journals (Sweden)

    MaryAnn Principato

    2014-04-01

    Full Text Available The staphylococcal enterotoxins (SEs are the products of Staphylococcus aureus and are recognized as the causative agents of classical food poisoning in humans following the consumption of contaminated food. While illness evoked by ingestion of the SE or its producer organism in tainted food are often self-limited, our current understanding regarding the evolution of S. aureus provokes the utmost concern. The organism and its associated toxins, has been implicated in a wide variety of disease states including infections of the skin, heart, sinuses, inflammatory gastrointestinal disease, toxic shock, and Sudden Infant Death Syndrome. The intricate relationship between the various subsets of immunocompetent T cells and accessory cells and the ingested material found within the gastrointestinal tract present daunting challenges to the maintenance of immunologic homeostasis. Dysregulation of the intricate balances within this environment has the potential for extreme consequences within the host, some of which are long-lived. The focus of this review is to evaluate the relevance of staphylococcal enterotoxin in the context of mucosal immunity, and the underlying mechanisms that contribute to the pathogenesis of gastrointestinal autoimmune disease.

  2. Contamination of beef products with staphylococcal classical enterotoxins in Egypt and Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Shawish, Reyad R.

    2016-04-01

    Full Text Available Food-borne pathogens are of high concern for public health and food safety. food poisoning is one of the most economically devastating types of food poisoning globally. The purpose of this study was to detect staphylococcal classical enterotoxins (SEs in processed beef from Kingdom of Saudi Arabia (KSA and Egypt. In the present investigation a total of 250 random processed meat samples (50 each of minced meat, beef burger, beef sausage, beef kofta and beef luncheon were collected from different super markets in the study area. Using conventional cultural methods, samples were cultured for isolation and identification of . Multiplex PCR was used to detect SEs of the classical type SEA, SEB, SEC and SED from isolates.The percentage presence of in minced meat, beef burger, beef sausage, beef kofta and beef luncheon was 38%, 22%, 30%, 32% and 12%, respectively. Multiplex PCR indicated that all examined samples contain different types of classical staphylococcal enterotoxins and only minced meat samples contained all four types of toxins. Multiplex PCR is efficient in detection of SEs from food and may be used in tracing of toxins to promote food hygiene. Implications of contamination of processed meat to food hygiene in the study area are highlighted.

  3. Recombinant Lactobacillus casei expressing Clostridium perfringens toxoids α, β2, ε and β1 gives protection against Clostridium perfringens in rabbits.

    Science.gov (United States)

    Zhao, Li; Guo, Zhihou; Liu, Jiali; Wang, Zi; Wang, Ruichong; Li, Yijing; Wang, Li; Xu, Yigang; Tang, Lijie; Qiao, Xinyuan

    2017-07-13

    The present study used Lactobacillus casei ATCC 393 as antigen delivery system to express C. perfringens toxoids α-β2-ε-β1 to construct the recombination Lactobacillus casei pPG-2-α-β2-ε-β1/L. casei 393. After being induced by 1% xylose, the specificity and integrity of recombinant strain were determined by Western-blotting. Rabbits as native animal model were immunized orally with pPG-2-α-β2-ε-β1/L. casei 393 and the titers of specific IgG and sIgA were determined by ELISA. The result showed that oral administration with the recombinants could elicit both local mucosal and systemic immune responses. The proliferation of spleen lymphocytes in rabbits immunized with pPG-2-α-β2-ε-β1/L. casei 393 was observed. Levels of IL-4 and IFN-γ produced were significantly higher in lymphocytes isolated from the vaccine group than those from the control groups. Flow cytometry assay showed that both the percentages of CD4+T cells and CD8+T cells from the vaccine group were significantly increased than the control groups. All these results showed that immunizing with recombinants can elicit both humoral immunity and cellular immunity. Besides, in order to determine the effectiveness of oral immunization with pPG-2-α-β2-ε-β1/L. casei 393, rabbits of vaccine group and control groups were challenged with 1×LD 100 unit of culture filtrate of C. perfringens type C and type D toxins respectively. After challenge, 100% of the immunized rabbits survived, while the rabbits of the control group were killed within 48h. Observation on histopathology showed that histopathological changes were obviously found in heart, liver, spleen, lung, kidney, intestine and brain of rabbits from the control groups, while no apparent histopathological change was observed in the vaccine group. All the results show that pPG-2-α-β2-ε-β1/L. casei 393 can eliciteffective immunoprotection against C. perfringens. All of these suggest that the use of pPG-2-α-β2-ε-β1/L. casei 393 can be

  4. Clostridium perfringens removal in different stages in a Drinking Water Treatments plant; Eliminacion de Clostidium perfringens en diversas etapas de una estacion de tratamiento de aguas potables

    Energy Technology Data Exchange (ETDEWEB)

    Ormad, M. P.; Lanao, M.; Goni, P.; Ibarz, C.; Ovelleiro, J. L.

    2008-07-01

    The purpose of this research is to evaluate the effectiveness of different stages, which take part in the conventional treatments used in the drinking water treatment plants in Spain, in the removal of a microbiological indicator of faecal pollution, Clostridium perfringens. The stages studied are pre oxidation with chlorine and ozone, chemical precipitation, adsorption with activated coal and filtration sand. The pre oxidation, either with sodium hypochlorite or with ozone, gets final recounts below the detection limit with the conditions studied (> 8 log). In the rest of stages, the removal is minimal, achieving 1,32 logarithmic units at best case. (Author) 6 refs.

  5. A probability model for enterotoxin production of Bacillus cereus as a function of pH and temperature

    Science.gov (United States)

    Bacillus cereus is frequently isolated from a variety of foods including vegetables, dairy products, meat, and other raw and processed foods. The bacterium is capable of producing enterotoxin and emetic toxin that can cause severe nausea, vomiting and diarrhea. The objectives of this study were to a...

  6. Clostridium perfringens types A and D associated with enterotoxemia in an 18-month-old goat

    Directory of Open Access Journals (Sweden)

    S. Miyashiro

    2007-01-01

    Full Text Available Postmortem examination of a Boer buck that died peracutely revealed bowel and liver diffusely congested and edematous. Kidney was apparently edematous. Clostridium perfringens type A was isolated from bowel and type D from kidney. Microscopic examination revealed large areas of necrosis in the renal cortex and medulla (pulpy kidney disease, hyperemia and centrilobular necrosis of the liver, necrosis of the small-intestine wall, pulmonary edema and congestion, intense hyperemia of the cerebellum, hyperemia and edema of the brain.

  7. Structural and biochemical analyses of a Clostridium perfringens sortase D transpeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Suryadinata, Randy, E-mail: randy.suryadinata@csiro.au; Seabrook, Shane A.; Adams, Timothy E.; Nuttall, Stewart D.; Peat, Thomas S., E-mail: randy.suryadinata@csiro.au [Commonwealth Scientific and Industrial Research Organisation, 343 Royal Parade, Parkville, Victoria 3052 (Australia)

    2015-06-30

    The structure of C. perfringens sortase D was determined at 1.99 Å resolution. Comparative biochemical and structural analyses revealed that this transpeptidase may represent a new subclass of the sortase D family. The assembly and anchorage of various pathogenic proteins on the surface of Gram-positive bacteria is mediated by the sortase family of enzymes. These cysteine transpeptidases catalyze a unique sorting signal motif located at the C-terminus of their target substrate and promote the covalent attachment of these proteins onto an amino nucleophile located on another protein or on the bacterial cell wall. Each of the six distinct classes of sortases displays a unique biological role, with sequential activation of multiple sortases often observed in many Gram-positive bacteria to decorate their peptidoglycans. Less is known about the members of the class D family of sortases (SrtD), but they have a suggested role in spore formation in an oxygen-limiting environment. Here, the crystal structure of the SrtD enzyme from Clostridium perfringens was determined at 1.99 Å resolution. Comparative analysis of the C. perfringens SrtD structure reveals the typical eight-stranded β-barrel fold observed in all other known sortases, along with the conserved catalytic triad consisting of cysteine, histidine and arginine residues. Biochemical approaches further reveal the specifics of the SrtD catalytic activity in vitro, with a significant preference for the LPQTGS sorting motif. Additionally, the catalytic activity of SrtD is most efficient at 316 K and can be further improved in the presence of magnesium cations. Since C. perfringens spores are heat-resistant and lead to foodborne illnesses, characterization of the spore-promoting sortase SrtD may lead to the development of new antimicrobial agents.

  8. [A case of freeze-dried gas gangrene antitoxin for the treatment of Clostridium perfringens sepsis].

    Science.gov (United States)

    Yoshida, Juichiro; Nakamura, Hideki; Yamada, Shinya; Sekoguchi, Satoru; Suzuki, Takahiro; Tomatsuri, Naoya; Sato, Hideki; Okuyama, Yusuke; Kimura, Hiroyuki; Yoshida, Norimasa

    2015-02-01

    A 66-year-old man was admitted to our hospital with high fever. We diagnosed a gas-containing liver abscess and performed percutaneous abscess drainage. However, 15 hours after admission, he developed massive intravascular hemolysis and acidosis. Sepsis due to Clostridium perfringens was suspected and we treated the patient intensively with multidisciplinary approaches, including antibiotics, mechanical ventilation, and renal replacement therapy. Furthermore, we administered freeze-dried gas gangrene antitoxin. Despite intensive care, the patient died 43 hours after admission.

  9. Veal calves produce less antibodies against C. perfringens alpha toxin compared to beef calves

    OpenAIRE

    Valgaeren, Bonnie; Pardon, Bart; Goossens, Evy; Verherstraeten, Stefanie; Roelandt, Sophie; Timbermont, Leen; Van Der Vekens, Nicky; Stuyvaert, Sabrina; Gille, Linde; Van Driessche, Laura; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip; Deprez, Piet

    2015-01-01

    Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, wher...

  10. Inactivation of Clostridium perfringens spores adhered onto stainless steel surface by agents used in a clean-in-place procedure.

    Science.gov (United States)

    Alzubeidi, Yasmeen S; Udompijitkul, Pathima; Talukdar, Prabhat K; Sarker, Mahfuzur R

    2018-07-20

    Enterotoxigenic Clostridium perfringens, a leading foodborne pathogen can be cross-contaminated from food processing stainless steel (SS) surfaces to the finished food products. This is mostly due to the high resistance of C. perfringens spores adhered onto SS surfaces to various disinfectants commonly used in food industries. In this study, we aimed to investigate the survivability and adherence of C. perfringens spores onto SS surfaces and then validate the effectiveness of a simulated Clean-in-Place (CIP) regime on inactivation of spores adhered onto SS surfaces. Our results demonstrated that, 1) C. perfringens spores adhered firmly onto SS surfaces and survived for at-least 48 h, unlike their vegetative cells who died within 30 min, after aerobic incubation at refrigerated and ambient temperatures; 2) Spores exhibited higher levels of hydrophobicity than vegetative cells, suggesting a correlation between cell surface hydrophobicity and adhesion to solid surfaces; 3) Intact spores were more hydrophobic than the decoated spores, suggesting a positive role of spore coat components on spores' hydrophobicity and thus adhesion onto SS surfaces; and finally 4) The CIP regime (NaOH + HNO 3 ) successfully inactivated C. perfringens spores adhered onto SS surfaces, and most of the effect of CIP regime appeared to be due to the NaOH. Collectively, our current findings may well contribute towards developing a strategy to control cross-contamination of C. perfringens spores into food products, which should help reducing the risk of C. perfringens-associated food poisoning outbreaks. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Effect of dietary mannan oligosaccharide from Saccharomyces cerevisiae on live performance of broilers under Clostridium perfringens challenge

    Directory of Open Access Journals (Sweden)

    Alaeldein M. Abudabos

    2013-04-01

    Full Text Available A 30-day broiler cage trial was conducted to evaluate the effect of dietary mannan oligosaccharide (MOS from one commercial product (SAF-Mannan on growth parameters, gut health and control pathogen colonization of broilers under Clostridium perfringens (C. perfringens challenge. One hundred, 0-day old male Ross 308 broilers were allocated in 4 experimental treatments for 30 days. The four dietary treatments were T1, standard broiler basal diets without any medication as a control (+CONT; T2, basal diets as in T1 plus C. perfringens challenge (-CONT; T3, enramycin 0.1 g/kg of feed plus C. perfringens challenge (ENRA; T4, SAF-Mannan at 0.5 g/kg in starter and finisher diets plus C. perfringens challenge (SAF. Overall, feed conversion ratio (FCR and body weight gain (BWG in treatments ENRA and SAF were significantly better (P<0.01 than the –CONT treatment, whereas treatment +CONT was intermediate and not different from SAF. Feed intake (FI was not influenced by treatment. SAF-Mannan supplementation was able to lower the ileal C. perfringens count as compared to all other treatments (P<0.05. The changes in C. perfringens count appear in parallel to observed improvement in the cumulative FCR.  The results from this study clearly indicated that SAF-Mannan could act as a replacement for antimicrobial growth promoters in broilers (AGPs. SAF-Mannan level of 0.05% was enough to achieve a response competitive with that of the antibiotic.

  12. Differential responses of cecal microbiota to fishmeal, Eimeria and Clostridium perfringens in a necrotic enteritis challenge model in chickens.

    Directory of Open Access Journals (Sweden)

    Dragana Stanley

    Full Text Available Clostridium perfringens causes enteric diseases in animals and humans. In poultry, avian-specific C. perfringens strains cause necrotic enteritis, an economically significant poultry disease that costs the global industry over $2 billion annually in losses and control measures. With removal of antibiotic growth promoters in some countries this disease appears to be on the rise. In experimental conditions used to study disease pathogenesis and potential control measures, reproduction of the disease relies on the use of predisposing factors such as Eimeria infection and the use of high protein diets, indicating complex mechanisms involved in the onset of necrotic enteritis. The mechanisms by which the predisposing factors contribute to disease progression are not well understood but it has been suggested that they may cause perturbations in the microbiota within the gastrointestinal tract. We inspected changes in cecal microbiota and short chain fatty acids (SCFA induced by Eimeria and fishmeal, in birds challenged or not challenged with C. perfringens. C. perfringens challenge in the absence of predisposing factors did not cause significant changes in either the alpha or beta diversity of the microbiota nor in concentrations of SCFA. Moreover, there was no C. perfringens detected in the cecal microbiota 2 days post-challenge without the presence of predisposing factors. In contrast, both fishmeal and Eimeria caused significant changes in microbiota, seen in both alpha and beta diversity and also enabled C. perfringens to establish itself post challenge. Eimeria had its strongest influence on intestinal microbiota and SCFA when combined with fishmeal. Out of 6 SCFAs measured, including butyric acid, none were significantly influenced by C. perfringens, but their levels were strongly modified following the use of both predisposing factors. There was little overlap in the changes caused following Eimeria and fishmeal treatments, possibly indicating

  13. Bayesian modeling of Clostridium perfringens growth in beef-in-sauce products.

    Science.gov (United States)

    Jaloustre, S; Cornu, M; Morelli, E; Noël, V; Delignette-Muller, M L

    2011-04-01

    Models on Clostridium perfringens growth which have been published to date have all been deterministic. A probabilistic model describing growth under non-isothermal conditions was thus proposed for predicting C. perfringens growth in beef-in-sauce products cooked and distributed in a French hospital. Model parameters were estimated from different types of data from various studies. A Bayesian approach was proposed to model the overall uncertainty regarding parameters and potential variability on the 'work to be done' (h(0)) during the germination, outgrowth and lag phase. Three models which differed according to their description of this parameter h(0) were tested. The model with inter-curve variability on h(0) was found to be the best one, on the basis of goodness-of-fit assessment and validation with literature data on results obtained under non-isothermal conditions. This model was used in two-dimensional Monte Carlo simulations to predict C. perfringens growth throughout the preparation of beef-in-sauce products, using temperature profiles recorded in a hospital kitchen. The median predicted growth was 7.8×10(-2) log(10) cfu·g(-1) (95% credibility interval [2.4×10(-2), 0.8]) despite the fact that for more than 50% of the registered temperature profiles cooling steps were longer than those required by French regulations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Recombinant Alpha, Beta, and Epsilon Toxins of Clostridium perfringens: Production Strategies and Applications as Veterinary Vaccines

    Directory of Open Access Journals (Sweden)

    Marcos Roberto A. Ferreira

    2016-11-01

    Full Text Available Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A–E according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans. Alpha, beta, and epsilon toxins are the main causes of disease. Vaccinations that generate neutralizing antibodies are the most common prophylactic measures that are currently in use. These vaccines consist of toxoids that are obtained from C. perfringens cultures. Recombinant vaccines offer several advantages over conventional toxoids, especially in terms of the production process. As such, they are steadily gaining ground as a promising vaccination solution. This review discusses the main strategies that are currently used to produce recombinant vaccines containing alpha, beta, and epsilon toxins of C. perfringens, as well as the potential application of these molecules as vaccines for mammalian livestock animals.

  16. Antibiotic resistance of Clostridium perfringens isolates from broiler chickens in Egypt.

    Science.gov (United States)

    Osman, K M; Elhariri, M

    2013-12-01

    The use of antibiotic feed additives in broiler chickens results in a high prevalence of resistance among their enteric bacteria, with a consequent emergence of antibiotic resistance in zoonotic enteropathogens. Despite growing concerns about the emergence of antibiotic-resistant strains, which show varying prevalences in different geographic regions, little work has been done to investigate this issue in the Middle East. This study provides insight into one of the world's most common and financially crippling poultry diseases, necrotic enteritis caused by Clostridium perfringens. The study was designed to determine the prevalence of antibiotic resistance in C. perfringens isolates from clinical cases of necrotic enteritis in broiler chickens in Egypt. A total of 125 isolates were obtained from broiler flocks in 35 chicken coops on 17 farms and were tested using the disc diffusion method. All 125 isolates were resistant to gentamicin, streptomycin, oxolinic acid, lincomycin, erythromycin and spiramycin. The prevalence of resistance to other antibiotics was also high: rifampicin (34%), chloramphenicol (46%), spectinomycin (50%), tylosin-fosfomycin (52%), ciprofloxacin (58%), norfloxacin (67%), oxytetracycline (71%), flumequine (78%), enrofloxacin (82%), neomycin (93%), colistin (94%), pefloxacin (94%), doxycycline (98%) and trimethoprim-sulfamethoxazole (98%). It is recommended that C. perfringens infections in Egypt should be treated with antibiotics for which resistant isolates are rare at present; namely, amoxicillin, ampicillin, cephradine, fosfomycin and florfenicol.

  17. Characterization of a unique class C acid phosphatase from Clostridium perfringens.

    Science.gov (United States)

    Reilly, Thomas J; Chance, Deborah L; Calcutt, Michael J; Tanner, John J; Felts, Richard L; Waller, Stephen C; Henzl, Michael T; Mawhinney, Thomas P; Ganjam, Irene K; Fales, William H

    2009-06-01

    Clostridium perfringens is a gram-positive anaerobe and a pathogen of medical importance. The detection of acid phosphatase activity is a powerful diagnostic indicator of the presence of C. perfringens among anaerobic isolates; however, characterization of the enzyme has not previously been reported. Provided here are details of the characterization of a soluble recombinant form of this cell-associated enzyme. The denatured enzyme was approximately 31 kDa and a homodimer in solution. It catalyzed the hydrolysis of several substrates, including para-nitrophenyl phosphate, 4-methylumbelliferyl phosphate, and 3' and 5' nucleoside monophosphates at pH 6. Calculated K(m)s ranged from 0.2 to 0.6 mM with maximum velocity ranging from 0.8 to 1.6 micromol of P(i)/s/mg. Activity was enhanced in the presence of some divalent cations but diminished in the presence of others. Wild-type enzyme was detected in all clinical C. perfringens isolates tested and found to be cell associated. The described enzyme belongs to nonspecific acid phosphatase class C but is devoid of lipid modification commonly attributed to this class.

  18. Beta Lactamase Producing Clostridium perfringens Bacteremia in an Elderly Man with Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Rashmi Mishra

    2016-01-01

    Full Text Available Clostridium perfringens bacteremia is associated with adverse outcomes. Known risk factors include chronic kidney disease, malignancy, diabetes mellitus, and gastrointestinal disease. We present a 74-year-old man admitted with confusion, vomiting, and abdominal pain. Exam revealed tachycardia, hypotension, lethargy, distended abdomen, and cold extremities. He required intubation and aggressive resuscitation for septic shock. Laboratory data showed leukocytosis, metabolic acidosis, acute kidney injury, and elevated lipase. CT scan of abdomen revealed acute pancreatitis and small bowel ileus. He was started on vancomycin and piperacillin-tazobactam. Initial blood cultures were positive for C. perfringens on day five. Metronidazole and clindamycin were added to the regimen. Repeat CT (day 7 revealed pancreatic necrosis. The patient developed profound circulatory shock requiring multiple vasopressors, renal failure requiring dialysis, and bacteremia with vancomycin-resistant enterococci. Hemodynamic instability precluded surgical intervention and he succumbed to multiorgan failure. Interestingly, our isolate was beta lactamase producing. We review the epidemiology, risk factors, presentation, and management of C. perfringens bacteremia. This case indicates a need for high clinical suspicion for clostridial sepsis and that extended spectrum beta lactam antibiotic coverage may be inadequate and should be supplemented with use of clindamycin or metronidazole if culture is positive, until sensitivities are known.

  19. Antimicrobial susceptibility of Clostridium perfringens isolated from domestic and wild animal species in Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Augusto de Oliveira Júnior

    2016-02-01

    Full Text Available Clostridium perfringens is a microorganism commonly found in the microbiota of humans and animals and a potential cause of enteric, muscle or nervous diseases. The treatment of these diseases is based on antimicrobial therapy and it is extremely important to know the antimicrobial susceptibility profile of the strains present in the region. The aim of this study was to evaluate the antimicrobial susceptibility of C. perfringens isolated from domestic and wild animals in Brazil against seven different antimicrobials. Forty-one strains from the stool samples of cattle (n = 12, buffalo (n = 2, goat (n = 3, dogs (n = 12 and wild carnivores (n = 12 were examined. The minimum inhibitory concentration was determined by the agar dilution method using Brucella agar supplemented with 5% of sheep blood, 0.1% of vitamin K, 0.1% of hemin and concentrations ranging from 0,25 to 256,0 mg L-1 of the following antibiotics: erythromycin, florfenicol, metronidazole, oxytetracycline, penicillin, tylosin, and vancomycin. All C. perfringens strains were susceptible to florfenicol, metronidazole, penicillin and vancomycin. Two strains (4.9% were resistant to erythromycin and tylosin, while five (12.2% were resistant to oxytetracycline, one of which (2.4% from an ocelot.

  20. Growth potential of Clostridium perfringens from spores in acidified beef, pork, and poultry products during chilling.

    Science.gov (United States)

    Juneja, Vijay K; Baker, David A; Thippareddi, H; Snyder, O Peter; Mohr, Tim B

    2013-01-01

    The ability of Clostridium perfringens to germinate and grow in acidified ground beef as well as in 10 commercially prepared acidified beef, pork, and poultry products was assessed. The pH of ground beef was adjusted with organic vinegar to achieve various pH values between 5.0 and 5.6; the pH of the commercial products ranged from 4.74 to 6.35. Products were inoculated with a three-strain cocktail of C. perfringens spores to achieve ca. 2-log (low) or 4-log (high) inoculum levels, vacuum packaged, and cooled exponentially from 54.4 to 7.2°C for 6, 9, 12, 15, 18, or 21 h to simulate abusive cooling; the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA-FSIS) recommends a cooling time of 6.5 h. Total germinated C. perfringens populations were determined after plating on tryptose-sulfite-cycloserine agar and incubating the plates anaerobically at 37°C for 48 h. In addition, C. perfringens growth from spores was assessed at an isothermal temperature of 44°C. Growth from spores was inhibited in ground beef with a pH of 5.5 or below, even during extended cooling from 54.4 to 7.2°C in 21 h. In ground beef with a pH of 5.6, the growth was >1 log after 18 h of cooling from 54.4 to 7.2°C. However, 15 h of cooling controlled the growth to product with a pH ranging from 4.74 to 5.17, both during exponential abusive cooling periods of up to 21 h and during storage for 21 h at 44°C. While product cooled exponentially from 54.4 to 7.2°C in 15 h or less, the pH 6.35 product supported growth, even after 6 h of cooling from 54.4 to 7.2°C. These challenge tests demonstrate that adjustment of ground beef to pH of 5.5 or less and of barbeque products to pH of 5.63 or less inhibits C. perfringens spore germination and outgrowth during extended cooling periods from 54.4 to 7.2°C up to 15 h. Therefore, safe cooling periods for products with homogeneous, lower pHs can be substantially longer.

  1. Mucin gene mRNA levels in broilers challenged with eimeria and/or Clostridium perfringens.

    Science.gov (United States)

    Kitessa, Soressa M; Nattrass, Gregory S; Forder, Rebecca E A; McGrice, Hayley A; Wu, Shu-Biao; Hughes, Robert J

    2014-09-01

    The effects of Eimeria (EM) and Clostridium perfringens (CP) challenges on the mRNA levels of genes involved in mucin (Muc) synthesis (Muc2, Muc5ac, Muc13, and trefoil family factor-2 [TFF2]), inflammation (tumor necrosis factor alpha [TNF-alpha] and interleukin-18 [IL-18]), and metabolic processes (cluster of differentiation [CD]36) in the jejunum of broilers were investigated. Two parallel experiments involving 1) EM challenge and 2) EM and CP challenges were conducted. The first experiment was a 2 X 2 study with 12 birds per treatment (N = 48) involving fishmeal substitution (25%) in the diet (FM) and EM challenge. The treatments were: Control (FM-, EM-), Fishmeal (FM+, EM-), EM challenge (FM-, EM+), and fishmeal substitution and EM challenge (FM+, EM+). The second experiment was a 2 X 2 X 2 experiment with six birds per treatment (N = 48) involving fishmeal (FM-, FM+), Eimeria (EM-, EM+), and C perfringens (CP-, CP+). In both arms of the study, male broilers were given a starter diet for the whole period of 16 days, except those assigned to FM+, where 25% of the starter ration was replaced with fishmeal from days 8 to 14. EM inoculation was performed on day 9 and CP inoculation on days 14 and 15. The EM challenge birds were euthanatized for sampling on day 13; postmortem examination and sampling for the Eimeria plus C perfringens challenge arm of the study were on day 16. In the Eimeria challenge arm of the study, fishmeal supplementation significantly suppressed the mRNA levels of TNF-alpha, TFF2, and IL-18 pre-CP inoculation but simultaneously increased the levels of Muc13 and CD36 mRNAs. Birds challenged with Eimeria exhibited increased mRNA levels of Muc13, Muc5ac, TNF-alpha, and IL-18. In the Eimeria and C. perfringens challenge arm, birds exposed to EM challenge exhibited significantly lower mRNA levels of Muc2 and CD36. The mRNA levels of CD36 were also significantly suppressed by CP challenge. Our results showed that the transcription of mucin synthesis

  2. Synergistic effect of embryo vaccination with Eimeria profilin and Clostridium perfringens NetB proteins on inducing protective immunity against necrotic enteritis in broiler chickens

    Science.gov (United States)

    The effects of embryo vaccination with Eimeria profilin plus Clostridium perfringens NetB toxin proteins in combination with the Montanide IMS-OVO adjuvant on the chicken immune response to necrotic enteritis were investigated using an E. maxima/C. perfringens co-infection model. Eighteen-day-old br...

  3. Evaluating the performance of a new model for predicting the growth of Clostridium perfringens in cooked, uncured meat and poultry products under isothermal, heating, and dynamically cooling conditions

    Science.gov (United States)

    Clostridium perfringens Type A is a significant public health threat and may germinate, outgrow, and multiply during cooling of cooked meats. This study evaluates a new C. perfringens growth model in IPMP Dynamic Prediction using the same criteria and cooling data in Mohr and others (2015), but inc...

  4. Expression of a Clostridium perfringens genome-encoded putative N-acetylmuramoyl-L-alanine amidase as a potential antimicrobial to control the bacterium

    Science.gov (United States)

    Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium that plays a substantial role in non-foodborne human, animal and avian diseases as well as human foodborne disease. Previously discovered C. perfringens bacteriophage lytic enzyme amino acid sequences were utilized to iden...

  5. Mastitis in dairy buffalo and cattle in Egypt due to Clostridium perfringens: prevalence, incidence, risk factors and costs.

    Science.gov (United States)

    Osman, K M; El-Enbaawy, M I; Ezzeldeen, N A; Hussein, H M G

    2009-12-01

    Although Clostridium perfringens is recognised as an important cause of clostridial enteric diseases, there is only limited knowledge about the association of particular C. perfringens toxinotypes (types A to E) with mastitis in domestic animals. In this study, mastitis was detected in 213/623 (34.12%) and 8/83 (9.64%) of the quarter milk samples collected from cases of clinical mastitis in cows and buffalo, respectively. The micro-organism was isolated in an incidence of 16/357 (4.48%) of milk samples from cows and 1/25 (4.0%) of samples from buffalo. Infection in one quarter was the most typical situation found (83% in cows and 87% in buffalo). Clostridium perfringens infection was also correlated to the season, with the highest proportion of isolates being found during spring (10.71%) and winter (7.07%). Using the classical toxin neutralisation typing method, 17 strains, isolated from cow and buffalo milk, were identified as C. perfringens type A, and selected for molecular analysis. Polymerase chain reaction detected the oecpa gene while the P/cpb and e/etx genes went undetected. The authors believe that C. perfringens has the potential to produce disease on its own or to predispose the udder to disease caused by major mastitis and environmental pathogens.

  6. Distribution of sewage indicated by Clostridium perfringens at a deep-water disposal site after cessation of sewage disposal.

    Science.gov (United States)

    Hill, R T; Straube, W L; Palmisano, A C; Gibson, S L; Colwell, R R

    1996-05-01

    Clostridium perfringens, a marker of domestic sewage contamination, was enumerated in sediment samples obtained from the vicinity of the 106-Mile Site 1 month and 1 year after cessation of sewage disposal at this site. C. perfringens counts in sediments collected at the disposal site and from stations 26 nautical miles (ca. 48 km) and 50 nautical miles (ca. 92 km) to the southwest of the site were, in general, more than 10-fold higher than counts from an uncontaminated reference site. C. perfringens counts at the disposal site were not significantly different between 1992 and 1993, suggesting that sewage sludge had remained in the benthic environment at this site. At stations where C. perfringens counts were elevated (i.e., stations other than the reference station), counts were generally higher in the top 1 cm and decreased down to 5 cm. In some cases, C. perfringens counts in the bottom 4 or 5 cm showed a trend of higher counts in 1993 than in 1992, suggesting bioturbation. We conclude that widespread sludge contamination of the benthic environment has persisted for at least 1 year after cessation of ocean sewage disposal at the 106-Mile Site.

  7. Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment

    DEFF Research Database (Denmark)

    Duan, Zhi; Hansen, Terese Holst; Hansen, Tina Beck

    2016-01-01

    With low temperature long time (LTLT) cooking it can take hours for meat to reach a final core temperature above 53 °C and germination followed by growth of Clostridium perfringens is a concern. Available and new growth data in meats including 154 lag times (tlag), 224 maximum specific growth rates...... (μmax) and 25 maximum population densities (Nmax) were used to developed a model to predict growth of C. perfringens during the coming-up time of LTLT cooking. New data were generate in 26 challenge tests with chicken (pH 6.8) and pork (pH 5.6) at two different slowly increasing temperature (SIT...... the SIT profiles. Similar results were found for non-heated and heated spores in chicken, whereas in pork C. perfringens 790-94 increased less than 1 log CFU/g. At 53 °C C. perfringens 790-94 was log-linearly inactivated. Observed and predicted concentrations of C. perfringens, at the time when 53 °C (log...

  8. Comparative transcriptome analysis by RNAseq of necrotic enteritis Clostridium perfringens during in vivo colonization and in vitro conditions.

    Science.gov (United States)

    Parreira, Valeria R; Russell, Kay; Athanasiadou, Spiridoula; Prescott, John F

    2016-08-12

    Necrotic enteritis (NE) caused by netB-positive type A Clostridium perfringens is an important bacterial disease of poultry. Through its complex regulatory system, C. perfringens orchestrates the expression of a collection of toxins and extracellular enzymes that are crucial for the development of the disease; environmental conditions play an important role in their regulation. In this study, and for the first time, global transcriptomic analysis was performed on ligated intestinal loops in chickens colonized with a netB-positive C. perfringens strain, as well as the same strain propagated in vitro under various nutritional and environmental conditions. Analysis of the respective pathogen transcriptomes revealed up to 673 genes that were significantly expressed in vivo. Gene expression profiles in vivo were most similar to those of C. perfringens grown in nutritionally-deprived conditions. Taken together, our results suggest a bacterial transcriptome responses to the early stages of adaptation, and colonization of, the chicken intestine. Our work also reveals how netB-positive C. perfringens reacts to different environmental conditions including those in the chicken intestine.

  9. Mode of action of plectasin-derived peptides against gas gangrene-associated Clostridium perfringens type A.

    Directory of Open Access Journals (Sweden)

    Xueling Zheng

    Full Text Available NZ2114 and MP1102 are novel plectasin-derived peptides with potent activity against Gram-positive bacteria. The antibacterial characteristics and mechanism of NZ2114 and MP1102 against gas gangrene-associated Clostridium perfringens were studied for the first time. The minimal inhibitory concentration and minimal bactericidal concentration of NZ2114 and MP1102 against resistant C. perfringens type A strain CVCC 46 were 0.91 μM. Based on the fractional inhibitory concentration index (FICI result, an additive or synergic effect was observed between NZ2114 (FICI = 0.5~0.75 or MP1102 (FICI = 0.375~1.0 and antibiotics. The flow cytometry, scanning and transmission electron microscopy analysis showed that both NZ2114 and MP1102 induced obviously membrane damage, such as the leakage of cellular materials, partial disappearance of the cell membrane and membrane peeling, as well as retracting cytoplasm and ghost cell. The gel retardation and circular dichroism (CD detection showed that NZ2114 and MP1102 could bind to C. perfringens genomic DNA and change the DNA conformation. Moreover, NZ2114 also interfered with the double helix and unwind the genomic DNA. The cell cycle analysis showed that C. perfringens CVCC 46 cells exposed to NZ2114 and MP1102 were arrested at the phase I. These data indicated that both NZ2114 and MP1102 have potential as new antimicrobial agents for gas gangrene infection resulting from resistant C. perfringens.

  10. Association and dissociation of Escherichia coli heat-stable enterotoxin from rat brush border membrane receptors

    International Nuclear Information System (INIS)

    Cohen, M.B.; Thompson, M.R.; Overmann, G.J.; Giannella, R.A.

    1987-01-01

    Escherichia coli heat-stable enterotoxin (ST) binds to receptors on rat intestinal cells and brush border membranes (BBM). We devised experiments to examine the reversibility of ST binding. We found that both 125 I-labeled ST and native ST were spontaneously dissociable from the BBM receptor. Radiolabeled ST bound to BBM was also dissociated by the addition of avid goat anti-ST antiserum. Furthermore, using a computer program for analysis of ligand binding, we calculated an apparent Ka of 10(8) liters/mol from competitive inhibition and saturation-binding data. This is significantly lower than the value previously reported by others. Our findings, of a lower Ka and a reversible ST-binding process, suggest that a therapeutic strategy of removing bound ST from its receptor or competing with the enterocyte receptor for unbound ST might be successful in terminating ST-induced secretion

  11. Staphylococcal enterotoxin C2 promotes osteogenesis and suppresses osteoclastogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Fu, Wei-ming; Zhu, Xiao; Wang, Hua; Wei-Mao Wang; Chen, Ju-yu; Liang, Yan; Zhang, Jin-fang; Kung, Hsiang-fu

    2014-03-10

    As a super-antigen, staphylococcal enterotoxin C2 (SEC2) stimulates the release of massive inflammatory cytokines such as interferon-gamma (IFN-γ), interleukin-1 (IL-1) and interleukin-2 (IL-2) which are documented to implicate osteoblast differentiation. In the present study, SEC2 was found to significantly improve the osteoblast differentiation by up-regulating BMP2 and Runx2/Cbfa1 expression. Interferon (IFN)-inducible gene IFI16, a co-activator of Runx2/Cbfa1, was also activated by SEC2 in the osteoblast differentiation. In addition, exogenous introduction of SEC2 stimulated OPG expression and suppressed RANKL, suggesting suppression of osteoclastogenesis in hMSCs. Therefore, our results displayed that SEC2 plays an important role in the commitment of MSC to the osteoblast and it might be a potential new therapeutic candidate for bone regeneration. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Comparative Effects of Food Preservatives on the Production of Staphylococcal Enterotoxin I from Staphylococcus aureus Isolate

    Directory of Open Access Journals (Sweden)

    Yanying Zhao

    2017-01-01

    Full Text Available Staphylococcal enterotoxin I (SEI is associated with staphylococcal food poisoning, but little is known about different food preservatives on the production of SEI. In this study, the effect of different food preservatives (sodium nitrite, polylysine, chitosan, and tea catechin on the bacteria growth, sei gene expression, and extracellular SEI production of Staphylococcus aureus isolate H4 was detected in tryptone soya broth (TSB culture. Our results showed that all of these preservatives depressed S. aureus H4 growth and the order of inhibitory effect was 0.8 g/L tea catechin > 6 g/L chitosan > 0.25 g/L polylysine > 0.4 g/L tea catechin > 0.15 g/L sodium nitrite. Furthermore, 0.25 g/L polylysine or 0.15 g/L sodium nitrite did not significantly alter sei gene transcription, while 6 g/L chitosan obviously increased the relative mRNA level of sei gene expression. 0.4 g/L tea catechin remarkably inhibited sei gene transcription. In addition, 0.15 g/L sodium nitrite and 6 g/L chitosan significantly enhanced SEI secretion. 0.25 g/L polylysine, especially 0.4 g/L tea catechin, sharply inhibited the level of SEI secretion. The results indicated that tea catechin not only suppressed Staphylococcus aureus growth, but also inhibited SEI production and secretion, suggesting that tea catechin may be better than sodium nitrite, polylysine, or chitosan for keeping the food from the contamination of SEI. These investigations would be useful for food industry to provide safer food products due to S. aureus enterotoxins-related control strategy.

  13. Studies on the mechanism of action of enterotoxin-induced fluid secretion in the gut

    International Nuclear Information System (INIS)

    Schirgi-Degen, A.

    1992-12-01

    The mechanism of action of Clostridium difficile enterotoxin A (CA), of Escherichia coli enterotoxin (STa) and of cholera toxin (CT), which are known to cause severe diarrhea, were studied in a preparation of ligated jejunal loops of anesthetized rats in vivo. The toxins were administered intraluminally. Pharmacological agents, which were tested for their potency to influence toxin-related effects, were administered subcutaneously. Net fluid transport was determined gravimetrically, prostaglandin (PG) E 2 -output into the lumen, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) contents in the mucosa were measured by radioimmunoassay, serotonin-(5-HT)-output into the lumen was determined by high performance liquid chromatography. The histopathological effects of CA and CT were examined by light- and scanning electron microscopy. All three toxins caused net fluid secretion (FS). 5-HT 2 -(ketanserin) and 5-HT 3 -receptor antagonists (tropisetron, ondansetron, granisetron) dose-dependently reduced or abolished CT- and STa-induced net FS, CA-induced net FS was not influenced. Indomethacin reduced CA-, CT- and STa-induced net FS. Elevation of PGE 2 -output occurred after exposure to CA and CT and was reduced by indomethacin. CA caused severe histopathological lesions and also CT time-dependently caused morphological changes, which may take part in the secretory response. It is concluded that 5-HT, using both 5-HT 2 - and 5-HT 3 -receptors, mediates CT- and STa, but not CA-induced FS. PGE 2 is involved in FS caused by all three toxins. CAMP and cGMP are presumedly no causative mediators of toxin-induced FS

  14. Detection of Staphylococcus aureus enterotoxins in sheep cheese and dairy desserts by multiplex PCR technique.

    Science.gov (United States)

    Ertas, Nurhan; Gonulalan, Zafer; Yildirim, Yeliz; Kum, Erhan

    2010-08-15

    The aim of this study was to investigate the presence of Staphylococcus aureus (S. aureus) and staphylococcal enterotoxins (SEs) genes in sheep cheese and dairy dessert samples by multiplex PCR (mPCR) technique. A total of 150 samples were analyzed consisting of 50 dairy dessert samples and 100 sheep cheese. Coagulase positive staphylococci (CPS) were found in 86 (57.3%) out of 150 analyzed samples. S. aureus were isolated from 60 (60%), 26 (52%) of sheep cheese and from of dairy desserts, respectively. Five suspected colonies were tested from each sheep cheese and dairy dessert samples for phenotypic and genotypic characterizations. A total of 430 isolates from the 86 positive samples were investigated in this study. Eighty (18.6%) isolates were characterized as S. aureus. The enterotoxin genes (sea, seb, sec, sed) were found in 13 (3.02%) out of 80 isolates. From cheese isolates, sea, seb and sed were detected in 5 (1.6%), 2 (0.6%), 1 (0.3%), respectively. From dairy dessert isolates, sea, sec and sed were detected in 3 (2.3%), 1 (0.76%), 1 (0.76%), respectively. The presence of SEs was identified in 12 (2.8%) out of 80 isolates by using ELISA technique. It was determined that these SEs had a distribution of 7 (1.6%) SEA, 2 (0.46%) SEB, 1 (0.23%) SEC, and 2 (0.46%) SED. SEs were found in 7 (2.3%) cheese and 5 (3.8%) dairy dessert isolates. In conclusion, S.aureus and their SEs were found to be present in sheep cheese and dairy desserts in this study. It is emphasized that the presence of S. aureus and their SEs genes in sheep cheese and dairy desserts may be regarded as a potential risk for human health. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Short communication: Pasteurization as a means of inactivating staphylococcal enterotoxins A, B, and C in milk.

    Science.gov (United States)

    Necidova, Lenka; Bogdanovicova, Katerina; Harustiakova, Danka; Bartova, Katerina

    2016-11-01

    Our aim was to assess the effect of pasteurization temperature on inactivation of staphylococcal enterotoxins (SE). Milk samples were inoculated with log 4.38 to 5.18cfu/mL of 40 different Staphylococcus aureus strains having the ability to produce types A, B, or C SE and incubated at 37°C for 24h to develop SE. This incubation was followed by heat treatment for 15 s at 72, 85, and 92°C. Samples were analyzed for Staph. aureus count by plate method and, specifically, for SE presence. An enzyme-linked immunofluorescent assay on a MiniVIDAS analyzer (bioMérieux, Marcy l'Étoile, France) was used to detect SE, which were determined semiquantitatively based on test values. The Staph. aureus count in milk before pasteurization did not affect the amount of SE. Before pasteurization, SEB was detected in the lowest amount compared with other SE types. Staphylococcal enterotoxins were markedly reduced with pasteurization and inactivated at pasteurization temperatures to an extent depending on the amount in the sample before pasteurization. After pasteurization at 72°C, SE were detected in 87.5% of samples (35/40), after pasteurization at 85°C in 52.5% of samples (21/40), and after pasteurization at 92°C in 45.0% of samples (18/40). We determined that SE may still persist in milk even when Staph. aureus bacteria are inactivated through pasteurization. Although pasteurization may partially inactivate SE in milk, a key measure in the prevention of staphylococcal enterotoxicosis linked to pasteurized milk consumption is to avoid any cold chain disruption during milk production and processing. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. A single-stranded DNA aptamer that selectively binds to Staphylococcus aureus enterotoxin B.

    Science.gov (United States)

    DeGrasse, Jeffrey A

    2012-01-01

    The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB) that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APT(SEB1), successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide.

  17. A single-stranded DNA aptamer that selectively binds to Staphylococcus aureus enterotoxin B.

    Directory of Open Access Journals (Sweden)

    Jeffrey A DeGrasse

    Full Text Available The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs. Staphylococcal food poisoning (SFP results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APT(SEB1, successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide.

  18. A new method of UA_CPE coupled with spectrophotometry for the faster and cost-effective detection of proline in fruit juice, honey, and wine.

    Science.gov (United States)

    Dağdeviren, Semahat; Altunay, Nail; Sayman, Yasin; Gürkan, Ramazan

    2018-07-30

    The study developed a new method for proline detection in honey, wine and fruit juice using ultrasound assisted-cloud point extraction (UA-CPE) and spectrophotometry. Initially, a quaternary complex was built, containing proline, histamine, Cu(II), and fluorescein at pH 5.5. Samples were treated with ethanol-water mixture before extraction and preconcentration, using an ultrasonic bath for 10 min at 40 °C (40 kHz, 300 W). After the optimization of variables affecting extraction efficiency, good linearity was obtained between 15 and 600 µg L -1 with sensitivity enhancement factor of 105. The limits of detection and quantification were 5.7 and 19.0 µg L -1 , respectively. The recovery percentage and relative standard deviations (RSD %) were between 95.3 and 103.3%, and 2.5 and 4.2%, respectively. The accuracy of the method was verified by the analysis of a standard reference material (SRM 2389a). Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Disruption in the cecal microbiota of chickens challenged with Clostridium perfringens and other factors was alleviated by Bacillus licheniformis supplementation.

    Science.gov (United States)

    Lin, Yicen; Xu, Shuai; Zeng, Dong; Ni, Xueqin; Zhou, Mengjia; Zeng, Yan; Wang, Hesong; Zhou, Yi; Zhu, Hui; Pan, Kangcheng; Li, Guangyao

    2017-01-01

    Clostridium perfringens can induce necrotic enteritis of chickens, which causes large economic losses every year. Bacillus licheniformis, a probiotic, can inhibit the growth of pathogenic bacteria such as Clostridium perfringens, thereby improving the health status of chickens. However, from a microbial ecology perspective, the mechanisms by which alterations to the gut microbiota improve health remain unknown. In this study, we used Illumina MiSeq sequencing to investigate the cecal microbiota of a negative control group (NC), a C. perfringens and Eimeria challenge group with fishmeal supplementation (PC), a group supplemented with fishmeal and infected with coccidia (FC), and group PC with B. licheniformis supplementation (BL). We found that the health status of C. perfringens-challenged chickens was compromised, and that B. licheniformis improved the growth of the chickens challenged with pathogens. Microbial diversity analysis and taxonomic profiling of groups NC, PC, and FC revealed a disturbed cecal microflora of the birds with C. perfringens. We also characterized the microbiota of the chickens in the BL group using several methods. Principal coordinate analysis demonstrated that, compared with group PC, the bacterial community structure of group BL was more similar to that of group NC. Linear discriminant analysis with effect size revealed less differentially represented bacterial taxa between groups BL and NC than between groups PC and NC. In addition, groups BL and NC appeared to have similar overrepresented microbial taxa (such as Bacteroides, Helicobacter, Megamonas, and Akkermansia) compared with group PC. Finally, a phylogenetic investigation of communities by reconstruction of unobserved states analysis indicated that large differences existed between group PC and groups NC and BL. In conclusion, pre-treatment with B. licheniformis reduced the disturbance of the cecal microbiome induced by challenge with C. perfringens and other factors in broiler

  20. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus.

    Science.gov (United States)

    Karau, Melissa J; Tilahun, Mulualem E; Krogman, Ashton; Osborne, Barbara A; Goldsby, Richard A; David, Chella S; Mandrekar, Jayawant N; Patel, Robin; Rajagopalan, Govindarajan

    2017-10-03

    Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.

  1. Distribution of sewage indicated by Clostridium perfringens at a deep-water disposal site after cessation of sewage disposal.

    OpenAIRE

    Hill, R T; Straube, W L; Palmisano, A C; Gibson, S L; Colwell, R R

    1996-01-01

    Clostridium perfringens, a marker of domestic sewage contamination, was enumerated in sediment samples obtained from the vicinity of the 106-Mile Site 1 month and 1 year after cessation of sewage disposal at this site. C. perfringens counts in sediments collected at the disposal site and from stations 26 nautical miles (ca. 48 km) and 50 nautical miles (ca. 92 km) to the southwest of the site were, in general, more than 10-fold higher than counts from an uncontaminated reference site. C. perf...

  2. Comparative genome analysis of clostridium perfringens isolates from healthy and necrotic enteritis infected poultry and diseased pigs

    DEFF Research Database (Denmark)

    Ronco, Troels; Lyhs, Ulrike; Stegger, Marc

    2015-01-01

    to be important for the development of NE in chickens and piglets, respectively, while the role of these toxins is less well elucidated in diseased turkeys. Methods: We carried out comparative genomic analysis of 40 C. perfringens genomes from healthy and NE-suffering chickens and turkeys, and diseased pigs using......B, NELoc-1 and -3 seem to play an important role in the NE pathogenesis in chickens, whereas cpb2 is important in diseased pigs. • The VirSR two-component system is involved in regulating NE-associated virulence genes. • Conjugative plasmid genes are widely spread among C. perfringens. • WGS is a powerful...

  3. Sequence variation in the alpha-toxin encoding plc gene of Clostridium perfringens strains isolated from diseased and healthy chickens

    DEFF Research Database (Denmark)

    Abildgaard, L; Engberg, RM; Pedersen, Karl

    2009-01-01

    The aim of the present study was to analyse the genetic diversity of the alpha-toxin encoding plc gene and the variation in a-toxin production of Clostridium perfringens type A strains isolated from presumably healthy chickens and chickens suffering from either necrotic enteritis (NE) or cholangio......-hepatitis. The a-toxin encoding plc genes from 60 different pulsed-field gel electrophoresis (PFGE) types (strains) of C perfringens were sequenced and translated in silico to amino acid sequences and the a-toxin production was investigated in batch cultures of 45 of the strains using an enzyme...

  4. Effect of a probiotic on prevention of diarrhea and Clostridium difficile and Clostridium perfringens shedding in foals

    DEFF Research Database (Denmark)

    Schoster, Angelika; Staempfli, H R; Abrahams, M

    2015-01-01

    of incidence and duration of diarrhea and fecal shedding of Clostridium perfringens and Clostridium difficile between treatment and age groups. RESULTS: The overall incidence of diarrhea was 41 of 72 (59%) and did not differ (P = 0.37) between treatment groups. Foals treated with probiotics were more likely...... of C. perfringens shedding was 55% with no difference between treatment groups (P = 0.23). The prevalence of C. difficile shedding was 11%. CONCLUSION AND CLINICAL IMPORTANCE: There was no benefit of administering a 3-week course of probiotics, but potential adverse effects were noted. Whether...

  5. Inhibitory effects of food additives derived from polyphenols on staphylococcal enterotoxin A production and biofilm formation by Staphylococcus aureus.

    Science.gov (United States)

    Shimamura, Yuko; Hirai, Chikako; Sugiyama, Yuka; Shibata, Masaharu; Ozaki, Junya; Murata, Masatsune; Ohashi, Norio; Masuda, Shuichi

    2017-12-01

    In this study, we examined the inhibitory effects of 14 food additives derived from polyphenol samples on staphylococcal enterotoxin A (SEA) production and biofilm formation by Staphylococcus aureus. Tannic acid AL (TA), Purephenon 50 W (PP) and Polyphenon 70A (POP) at 0.25 mg/mL and Gravinol®-N (GN), Blackcurrant polyphenol AC10 (BP), and Resveratrol-P5 (RT) at 1.0 mg/mL significantly decreased SEA production by S. aureus C-29 (p Food additives derived from polyphenols have viability to be used as a means to inhibit the enterotoxin production and control the biofilm formation of foodborne pathogens.

  6. Effects of nisin and temperature on survival, growth, and enterotoxin production characteristics of psychrotrophic Bacillus cereus in beef gravy.

    OpenAIRE

    Beuchat, L R; Clavero, M R; Jaquette, C B

    1997-01-01

    The presence of psychrotrophic enterotoxigenic Bacillus cereus in ready-to-serve meats and meat products that have not been subjected to sterilization treatment is a public health concern. A study was undertaken to determine the survival, growth, and diarrheal enterotoxin production characteristics of four strains of psychrotrophic B. cereus in brain heart infusion (BHI) broth and beef gravy as affected by temperature and supplementation with nisin. A portion of unheated vegetative cells from...

  7. Effect of tannins on the in vitro growth of Clostridium perfringens.

    Science.gov (United States)

    Elizondo, Ana M; Mercado, Elsa C; Rabinovitz, Bettina C; Fernandez-Miyakawa, Mariano E

    2010-10-26

    Vegetable tannins are water-soluble polyphenolic compounds of varying molecular weights that occur abundantly in nature. The diet of many free-ranging wild animals contains significant amounts of tannins. Also, commercial tannins are used in animal industry as food additives to improve animal performance. In order to further determine the capacity of tannins to inhibit the development of intestinal diseases produced by Clostridium pefringens, we evaluated here the effect of tannins from quebracho, chestnut or combinations of both on C. perfringens and their toxins. The C. perfringens (types A, B, C, D and E) growth obtained from the intestine of healthy and diseased animals was reduced in a dose-dependent manner in the presence of quebracho tannins, chestnut tannins, combinations of both or a commercial formula based in these tannins. Although the minimal inhibitory concentration of both tannins varied between isolates, no statistically significant differences were observed between isolates from healthy or sick animals. Comparative analysis showed that the concentrations of quebracho tannin inhibiting the growth of C. perfringens were higher than chestnut tannin. In fact, antibacterial effect of quebracho tannin was increased up to 20 times with the addition of 25% of chestnut tannin and 85 times with 75% of chestnut tannin. Antibacterial activity of the commercial product was up to ~50 times higher than quebracho tannin alone. Quebracho tannin showed partial bactericidal activity, whereas chestnut tannin activity was stronger. Both tannins were able to reduce the alpha toxin lecithinase activity and epsilon toxin cytotoxicity in MDCK cells. These results suggest that tannin-supplemented diet could be useful to prevent some clostridial diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Cellular Entry of Clostridium perfringens Iota-Toxin and Clostridium botulinum C2 Toxin

    Directory of Open Access Journals (Sweden)

    Masaya Takehara

    2017-08-01

    Full Text Available Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin are composed of two non-linked proteins, one being the enzymatic component and the other being the binding/translocation component. These latter components recognize specific receptors and oligomerize in plasma membrane lipid-rafts, mediating the uptake of the enzymatic component into the cytosol. Enzymatic components induce actin cytoskeleton disorganization through the ADP-ribosylation of actin and are responsible for cell rounding and death. This review focuses upon the recent advances in cellular internalization of clostridial binary toxins.

  9. Cellular Entry of Clostridium perfringens Iota-Toxin and Clostridium botulinum C2 Toxin.

    Science.gov (United States)

    Takehara, Masaya; Takagishi, Teruhisa; Seike, Soshi; Oda, Masataka; Sakaguchi, Yoshihiko; Hisatsune, Junzo; Ochi, Sadayuki; Kobayashi, Keiko; Nagahama, Masahiro

    2017-08-11

    Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin are composed of two non-linked proteins, one being the enzymatic component and the other being the binding/translocation component. These latter components recognize specific receptors and oligomerize in plasma membrane lipid-rafts, mediating the uptake of the enzymatic component into the cytosol. Enzymatic components induce actin cytoskeleton disorganization through the ADP-ribosylation of actin and are responsible for cell rounding and death. This review focuses upon the recent advances in cellular internalization of clostridial binary toxins.

  10. Characterization of Staphylococcus aureus strains and evidence for the involvement of non-classical enterotoxin genes in food poisoning outbreaks.

    Science.gov (United States)

    Ciupescu, Laurentiu-Mihai; Auvray, Frederic; Nicorescu, Isabela Madalina; Meheut, Thomas; Ciupescu, Veronica; Lardeux, Anne-Laure; Tanasuica, Rodica; Hennekinne, Jacques-Antoine

    2018-06-05

    To an increasing extent, molecular and genetic characterization is now used to investigate foodborne outbreaks. The aim of this study was to seek molecular links among coagulase-positive staphylococci (CPS) isolated from three recent food poisoning outbreaks in Romania using polymerase chain reaction and pulsed-field gel electrophoresis (PFGE) techniques. Nineteen CPS isolates were identified as Staphylococcus aureus by detection of the 23S rDNA gene. Among them, 15 carried at least one staphylococcal enterotoxin-encoding gene (se). The Calarași outbreak strains grouped in pulsotype 2 and were sed/sej/ser-positive, whereas the Arad outbreak strains clustered in pulsotype 17 and were either sed/seg/sei/sej/ser- or seg/sei-positive. The Pitești outbreak strains clustered in pulsotype 1 and, surprisingly, possessed only one enterotoxin gene, i.e. seh. Similar to other European countries, the seh gene has been identified with increasing frequency in Romanian outbreaks; this highlights the importance of considering the application of methods recommended for staphylococcal enterotoxin regulation in Europe.

  11. Alphitobius diaperinus spp como veiculador de Clostridium perfringens em granjas avícolas do interior paulista - Brasil Alphitobius diaperinus spp as a vector of Clostridium perfringens in broiler houses in the state of São Paulo - Brazil

    Directory of Open Access Journals (Sweden)

    Juliano Vittori

    2007-06-01

    Full Text Available O besouro Alphitobius diaperinus spp (cascudinho é visto como uma importante praga da avicultura mundial. Por suas características comportamentais e hábitos biológicos que dificultam seu controle, é considerado um vetor de agentes patogênicos. O objetivo desta pesquisa foi investigar o cascudinho como possível vetor de Clostridium perfringens em granjas avícolas industriais, localizadas em diferentes regiões do interior Paulista. Através de métodos bacteriológicos convencionais, em 40 amostras analisadas, foram encontradas contagens significativas de Clostridium perfringens em todas elas. A partir dos resultados obtidos, pôde-se demonstrar o potencial deste inseto como vetor do agente responsável pela enterite necrótica.The Alphitobius diaperinus spp (lesser mealworm is considered an important world poultry plague. Due to its behavior characteristics and biological habits that make its control difficult it is considered a vector of pathogenic agents. The objective of this research was to investigate the little mealworm as possible vector of Clostridium perfringens in broiler houses, located in different parts of the state of São Paulo. Through conventional bacteriological methods, 40 samples of little mealworm collected were analyzed. Clostridium perfringens was found in all of the samples and the potential of this insect as vector of the necrotic enteritis was demonstrated.

  12. Produção e caracterização de anticorpos monoclonais contra toxina épsilon de Clostridium perfringens Tipo D Production and characterization of monoclonal antibodies against Clostridium perfringens Type D epsilon toxin

    Directory of Open Access Journals (Sweden)

    Theonys Diógenes Freitas

    2009-02-01

    Full Text Available Clostridium perfringens tipo D é o agente etiológico da enterotoxemia em ruminantes, causada pela toxina épsilon e caracterizada por edema cardíaco, pulmonar, renal e cerebral. Anticorpos monoclonais contra toxina épsilon de C. perfringens tipo D foram produzidos a partir da fusão da linhagen de mieloma P3-X63-Ag8 653 com células do baço de camundongos Balb/c imunizados com o toxóide épsilon. Seis linhagens de híbridos secretores de anticorpos monoclonais das classes e IgM e IgG foram estabelecidas.Clostridium perfringens type D is the aetiological agent of enterotoxemia in ruminants. The disease is caused by epsilon toxin characterized by cardiac, pulmonary, kidney and brain edema. Monoclonal antibodies were produced by using myeloma cell line P3-X63-Ag8 653 fused with spleen cells from Balb/c mice, immunized with epsilon toxoid of C. perfringens type D. Six hybrids were established secreting monoclonal antibodies of the IgM class and IgG3 subclass.

  13. Effects of nisin and temperature on survival, growth, and enterotoxin production characteristics of psychrotrophic Bacillus cereus in beef gravy.

    Science.gov (United States)

    Beuchat, L R; Clavero, M R; Jaquette, C B

    1997-05-01

    The presence of psychrotrophic enterotoxigenic Bacillus cereus in ready-to-serve meats and meat products that have not been subjected to sterilization treatment is a public health concern. A study was undertaken to determine the survival, growth, and diarrheal enterotoxin production characteristics of four strains of psychrotrophic B. cereus in brain heart infusion (BHI) broth and beef gravy as affected by temperature and supplementation with nisin. A portion of unheated vegetative cells from 24-h BHI broth cultures was sensitive to nisin as evidenced by an inability to form colonies on BHI agar containing 10 micrograms of nisin/ml. Heat-stressed cells exhibited increased sensitivity to nisin. At concentrations as low as 1 microgram/ml, nisin was lethal to B. cereus, the effect being more pronounced in BHI broth than in beef gravy. The inhibitory effect of nisin (1 microgram/ml) was greater on vegetative cells than on spores inoculated into beef gravy and was more pronounced at 8 degrees C than at 15 degrees C. Nisin, at a concentration of 5 or 50 micrograms/ml, inhibited growth in gravy inoculated with vegetative cells and stored at 8 or 15 degrees C, respectively, for 14 days. Growth of vegetative cells and spores of B. cereus after an initial period of inhibition is attributed to loss of activity of nisin. One of two test strains produced diarrheal enterotoxin in gravy stored at 8 or 15 degrees C within 9 or 3 days, respectively. Enterotoxin production was inhibited in gravy supplemented with 1 microgram of nisin/ml and stored at 8 degrees C for 14 days; 5 micrograms of nisin/ml was required for inhibition at 15 degrees C. Enterotoxin was not detected in gravy in which less than 5.85 log10 CFU of B. cereus/ml had grown. Results indicate that as little as 1 microgram of nisin/ml may be effective in inhibiting or retarding growth of and diarrheal enterotoxin production by vegetative cells and spores of psychrotrophic B. cereus in beef gravy at 8 degrees C, a

  14. The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens.

    Science.gov (United States)

    Antonissen, Gunther; Van Immerseel, Filip; Pasmans, Frank; Ducatelle, Richard; Haesebrouck, Freddy; Timbermont, Leen; Verlinden, Marc; Janssens, Geert Paul Jules; Eeckhaut, Venessa; Eeckhout, Mia; De Saeger, Sarah; Hessenberger, Sabine; Martel, An; Croubels, Siska

    2014-01-01

    Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (Peffect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.

  15. Human alpha-defensin-1 protects cells from intoxication with Clostridium perfringens iota toxin.

    Science.gov (United States)

    Fischer, Stephan; Popoff, Michel R; Barth, Holger

    2018-03-01

    Iota toxin is produced by Clostridium perfringens type E strains and associated with diarrhea in cattle and lambs. This binary protein toxin comprises the enzyme component iota a (Ia), which ADP-ribosylates G-actin, and the separate transport component iota b (Ib), which delivers Ia into the cytosol of target cells. Ib binds to cell receptors and forms biologically active toxin complexes with Ia, which cause rounding of adherent cells due to the destruction of the actin cytoskeleton. Here, we report that the human peptide α-defensin-1 protects cultured cells including human colon cells from intoxication with iota toxin. In contrast, the related ß-defensin-1 had no effect, indicating a specific mode of action. The α-defensin-1 did not inhibit ADP-ribosylation of actin by Ia in vitro. Pretreatment of Ib with α-defensin-1 prior to addition of Ia prevented intoxication. Additionally, α-defensin-1 protected cells from cytotoxic effects mediated by Ib in the absence of Ia, implicating that α-defensin-1 interacts with Ib to prevent the formation of biologically active iota toxin on cells. In conclusion, the findings contribute to a better understanding of the functions of α-defensin-1 and suggest that this human peptide might be an attractive starting point to develop novel pharmacological options to treat/prevent diseases associated with iota toxin-producing Clostridium perfringens strains.

  16. Prevalence of C. botulinum and C. perfringens spores in food products available on Polish market

    Directory of Open Access Journals (Sweden)

    Grenda Tomasz

    2017-09-01

    Full Text Available Introduction: The aim of this study was to evaluate the prevalence of Clostridium botulinum and Clostridium perfringens in food samples purchased from Polish producers. Material and Methods: The analyses were performed on 260 food samples collected in Lublin and Subcarpathian regions: 56 of smoked meat, 21 of pork meat, 20 of dairy products, 26 of vegetable and fruit preserves, 40 of ready-to-eat meals, 27 of fish preserves, and 70 of honey collected directly from apiaries. Results: C. botulinum strains were isolated from 2.3% (6/260 of samples and the isolates were classified as toxin types A (4/260 and B (2/260. C. perfringens strains were isolated from 14% (37/260 of samples. All the isolates were classified as toxin type A, 28 of them were able also to produce α toxin and 9 - β2 toxin. Conclusion: On the basis of the obtained results it could be suggested that risk assessment, especially regarding the entire honey harvesting process, should be provided in order to ensure the microbiological safety of the products to be consumed by infants and people with a weakened immune system.

  17. Antimicrobial activities of six essential oils commonly used as condiments in Brazil against Clostridium perfringens

    Directory of Open Access Journals (Sweden)

    Marcela Radaelli

    2016-06-01

    Full Text Available Abstract Despite recent advances in food production technology, food-borne diseases (FBD remain a challenging public health concern. In several countries, including Brazil, Clostridium perfringens is among the five main causative agents of food-borne diseases. The present study determines antimicrobial activities of essential oils of six condiments commonly used in Brazil, viz., Ocimum basilicum L. (basil, Rosmarinus officinalis L. (rosemary, Origanum majorana L. (marjoram, Mentha × piperita L. var. Piperita (peppermint, Thymus vulgaris L. (thyme and Pimpinella anisum L. (anise against C. perfringens strain A. Chemical compositions of the oils were determined by GC–MS (gas chromatography–mass spectrometry. The identities of the isolated compounds were established from the respective Kováts indices, and a comparison of mass spectral data was made with those reported earlier. The antibacterial activity was assessed from minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC using the microdilution method. Minimum inhibitory concentration values were 1.25 mg mL-1 for thyme, 5.0 mg mL-1 for basil and marjoram, and 10 mg mL-1 for rosemary, peppermint and anise. All oils showed bactericidal activity at their minimum inhibitory concentration, except anise oil, which was only bacteriostatic. The use of essential oils from these common spices might serve as an alternative to the use of chemical preservatives in the control and inactivation of pathogens in commercially produced food systems.

  18. Antimicrobial activities of six essential oils commonly used as condiments in Brazil against Clostridium perfringens.

    Science.gov (United States)

    Radaelli, Marcela; da Silva, Bárbara Parraga; Weidlich, Luciana; Hoehne, Lucélia; Flach, Adriana; da Costa, Luiz Antonio Mendonça Alves; Ethur, Eduardo Miranda

    2016-01-01

    Despite recent advances in food production technology, food-borne diseases (FBD) remain a challenging public health concern. In several countries, including Brazil, Clostridium perfringens is among the five main causative agents of food-borne diseases. The present study determines antimicrobial activities of essential oils of six condiments commonly used in Brazil, viz., Ocimum basilicum L. (basil), Rosmarinus officinalis L. (rosemary), Origanum majorana L. (marjoram), Mentha × piperita L. var. Piperita (peppermint), Thymus vulgaris L. (thyme) and Pimpinella anisum L. (anise) against C. perfringens strain A. Chemical compositions of the oils were determined by GC-MS (gas chromatography-mass spectrometry). The identities of the isolated compounds were established from the respective Kováts indices, and a comparison of mass spectral data was made with those reported earlier. The antibacterial activity was assessed from minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the microdilution method. Minimum inhibitory concentration values were 1.25mgmL(-1) for thyme, 5.0mgmL(-1) for basil and marjoram, and 10mgmL(-1) for rosemary, peppermint and anise. All oils showed bactericidal activity at their minimum inhibitory concentration, except anise oil, which was only bacteriostatic. The use of essential oils from these common spices might serve as an alternative to the use of chemical preservatives in the control and inactivation of pathogens in commercially produced food systems. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  19. The Isolation and Detection of Staphylococcus aureus Enterotoxins A-E and TSST-1 Genes from Different Sources by PCR Method

    Directory of Open Access Journals (Sweden)

    Norouzi J

    2012-09-01

    Full Text Available Background and Objectives: Enterotoxins and toxic shock syndrome toxin–1 (TSST-1 are an important virulence factor of S. aureus. The purpose of this study was to analyze the presence of S. aureus enterotoxin (sea-see and tst genes in the samples that collected from different sources with PCR method. Methods: During 5 months from 150 collected samples, 80 strains were identified as S. aureus. PCR reaction was used for investigation on the presence of genes for staphylococcal enterotoxins (A-E and toxic shock syndrome toxin-1 (TSST-1. Results: Fifty three samples (66.25% out of 80 samples were positive for one or more ETs and TSST-1 genes. of these positive strains, 17 (32.07% were positive for sea 39 (73.58% for seb, 30 (56.6% for sec, 2 (3.7% for sed, 21 (39.62% for see, and 14 (26.41% for tst. Enterotoxins and tst in 40 samples (75.47% observed.Conclusion: In this study, high prevalence of S. aureus, its enterotoxin, and tst genes were observed in clinical samples, food samples, and healthy people. This fact emphasizes on the role of human as original source and carrier of S. aureus. Also, use of PCR reaction for detection of these genes in S. aureus that isolated from various sources is recommended.

  20. [Poisoning by enterotoxin from Staphylococcus aureus associated with mocha pastry. Microbiology and epidemiology].

    Science.gov (United States)

    Escartín, E F; Saldaña-Lozano, J; Montiel-Falcón, A

    1998-01-01

    A brief description of a foodborne outbreak due to S. aureus enterotoxin associated with the consumption of mocha cake in the city of Guadalajara is presented. The cake was prepared in a bakery and affected nearly 100 persons. S. aureus was isolated from the nose and skin of one of the pastry cooks. A S. aureus strain isolated from the cake involved in the outbreak was not only unable to grow in the mocha cream, but it actually decreased in numbers by 2 log after 72 h of storage at 30 degrees C. The pH of mocha cream ranged from 6.2 to 6.6, and water activity from 0.833 to 0.859, with a media of 0.841. In preparing mocha cake at the shop, one half of the dough used to be sprayed with a sucrose solution in water (20% w/v); mocha cream was spread on the other half of the dough before overlapping the two halves. When mocha cake was prepared in this manner, and stored at 30 degrees C, S. aureus increased in number by more than 4 log after 48 h. S. aureus did not grow in the cake stored at 4-7 degrees C. Contributory factors in this outbreak were an increase of water activity in the interphase of the mocha and the cake dough, storage of the cake in an unrefrigerated area, and an unusually high ambient temperature (28-32 degrees C) at that time.

  1. Formation of cereulide and enterotoxins by Bacillus cereus in fermented African locust beans

    DEFF Research Database (Denmark)

    Thorsen, Line; Azokpota, Paulin; Munk Hansen, Bjarne

    2011-01-01

    Afitin, iru and sonru are three spontaneously fermented African locust bean Benin condiments. The fermentation processes are exothermic, with temperatures mostly being above 40 °C. A total of 19 predominant Bacillus cereus isolates from afitin, iru and sonru, were investigated. The enterotoxin...... genes nhe (A, B, C) were present in all 19 isolates, the hbl (A, C, D) in one (afitin), and the cytK gene in three isolates (afitin). Levels of cytotoxicity to Vero cells and NheA production in BHI-broth was within the range of known diarrheal outbreak strains. Autoclaved cooked African locust beans...... inoculated with emetic (cereulide producing) B. cereus Ba18H2/RIF supported growth at 25, 30 and 40 °C with highly different maximum cereulide productions of 6 ± 5, 97 ± 3 and 0.04 ± 0.02 μg/g beans, respectively (48 h). For non-autoclaved cooked beans inoculated with 2, 4 and 6 log10 B. cereus Ba18H2/RIF...

  2. Colorimetric determination of staphylococcal enterotoxin B via DNAzyme-guided growth of gold nanoparticles

    International Nuclear Information System (INIS)

    Zhou, Dandan; Chen, Hui; Xie, Guoming; Cao, Xianqing; Chen, Xueping; Zhang, Xing

    2016-01-01

    The authors describe a colorimetric method for the determination of the staphylococcal enterotoxin B (SEB) that also allows for visual readout. The assay is based on the growth of gold nanoparticles (AuNPs) mediated by a hemin/G-quadruplex DNAzyme which generates a color change from red to blue in the presence of SEB. The method is enzyme-free and does not require a label. The kinetics of the formation of the AuNPs is controlled by the hemin/G-quadruplex DNAzyme and this is key to the signal generation mechanism. In the presence of SEB, the reactions between aptamer and target modulated the amount of single probe G strands that form DNAzyme capable of consuming hydrogen peroxide. The growth process of AuNPs is influenced by the resulting concentration of H 2 O 2 and leads to the color change. Under optimal conditions, a linear relationship exists between absorbance and SEB concentration in the range from 0.1 to 500 pg·mL -1 which covers the clinically relevant range. In case of visual detection, the lower limit of detection is 1 pg·mL −1 . The assay described here is sensitive, comparably inexpensive and can detect SEB rapidly without the need for sophisticated equipment. In our perception, the method has a wide scope in that it may be adapted to various nucleic acids, proteins and other biomolecules if respective aptamers are available. (author)

  3. From Escherichia coli heat-stable enterotoxin to mammalian endogenous guanylin hormones

    International Nuclear Information System (INIS)

    Lima, A.A.M.; Fonteles, M.C.

    2014-01-01

    The isolation of heat-stable enterotoxin (STa) from Escherichia coli and cholera toxin from Vibrio cholerae has increased our knowledge of specific mechanisms of action that could be used as pharmacological tools to understand the guanylyl cyclase-C and the adenylyl cyclase enzymatic systems. These discoveries have also been instrumental in increasing our understanding of the basic mechanisms that control the electrolyte and water balance in the gut, kidney, and urinary tracts under normal conditions and in disease. Herein, we review the evolution of genes of the guanylin family and STa genes from bacteria to fish and mammals. We also describe new developments and perspectives regarding these novel bacterial compounds and peptide hormones that act in electrolyte and water balance. The available data point toward new therapeutic perspectives for pathological features such as functional gastrointestinal disorders associated with constipation, colorectal cancer, cystic fibrosis, asthma, hypertension, gastrointestinal barrier function damage associated with enteropathy, enteric infection, malnutrition, satiety, food preferences, obesity, metabolic syndrome, and effects on behavior and brain disorders such as attention deficit, hyperactivity disorder, and schizophrenia

  4. Colorimetric DNAzyme Biosensor for Convenience Detection of Enterotoxin B Harboring Staphylococcus aureus from Food Samples.

    Science.gov (United States)

    Mondal, Bhairab; N, Bhavanashri; Ramlal, Shylaja; Kingston, Joseph

    2018-02-14

    In the present study, a colorimetric DNAzymes biosensor strategy was devised in combination with immunomagnetic separation for rapid and easy detection of enterotoxin B harboring Staphylococcus aureus from food and clinical samples. The method employs immunocapture of S. aureus and amplification of seb gene by DNAzyme complementary sequence integrated forward primer and with specific reverse primer. The DNAzyme sequence integrated dsDNA PCR products when treated with hemin and TMB (3,3',5,5'-tetramethylbenzidine) in the presence of H 2 O 2 produce colorimetric signal. A linear relationship of optical signal with the initial template of seb was obtained which could be monitored by visually or spectrophotrometrically for qualitative and quantitative detection. The limit of detection for the assay was approximately 10 2 CFU/mL of seb gene harboring target. This method is convenient compared to gel based and ELISA systems. Further, spiking studies and analysis on natural samples emphasized the robustness and applicability of developed method. Altogether, the established assay could be a reliable alternative, low-cost, viable detection tool for the routine investigation of seb from food and clinical sources.

  5. Plant-Derived Polyphenols Interact with Staphylococcal Enterotoxin A and Inhibit Toxin Activity.

    Science.gov (United States)

    Shimamura, Yuko; Aoki, Natsumi; Sugiyama, Yuka; Tanaka, Takashi; Murata, Masatsune; Masuda, Shuichi

    2016-01-01

    This study was performed to investigate the inhibitory effects of 16 different plant-derived polyphenols on the toxicity of staphylococcal enterotoxin A (SEA). Plant-derived polyphenols were incubated with the cultured Staphylococcus aureus C-29 to investigate the effects of these samples on SEA produced from C-29 using Western blot analysis. Twelve polyphenols (0.1-0.5 mg/mL) inhibited the interaction between the anti-SEA antibody and SEA. We examined whether the polyphenols could directly interact with SEA after incubation of these test samples with SEA. As a result, 8 polyphenols (0.25 mg/mL) significantly decreased SEA protein levels. In addition, the polyphenols that interacted with SEA inactivated the toxin activity of splenocyte proliferation induced by SEA. Polyphenols that exerted inhibitory effects on SEA toxic activity had a tendency to interact with SEA. In particular, polyphenol compounds with 1 or 2 hexahydroxydiphenoyl groups and/or a galloyl group, such as eugeniin, castalagin, punicalagin, pedunculagin, corilagin and geraniin, strongly interacted with SEA and inhibited toxin activity at a low concentration. These polyphenols may be used to prevent S. aureus infection and staphylococcal food poisoning.

  6. Plant-Derived Polyphenols Interact with Staphylococcal Enterotoxin A and Inhibit Toxin Activity.

    Directory of Open Access Journals (Sweden)

    Yuko Shimamura

    Full Text Available This study was performed to investigate the inhibitory effects of 16 different plant-derived polyphenols on the toxicity of staphylococcal enterotoxin A (SEA. Plant-derived polyphenols were incubated with the cultured Staphylococcus aureus C-29 to investigate the effects of these samples on SEA produced from C-29 using Western blot analysis. Twelve polyphenols (0.1-0.5 mg/mL inhibited the interaction between the anti-SEA antibody and SEA. We examined whether the polyphenols could directly interact with SEA after incubation of these test samples with SEA. As a result, 8 polyphenols (0.25 mg/mL significantly decreased SEA protein levels. In addition, the polyphenols that interacted with SEA inactivated the toxin activity of splenocyte proliferation induced by SEA. Polyphenols that exerted inhibitory effects on SEA toxic activity had a tendency to interact with SEA. In particular, polyphenol compounds with 1 or 2 hexahydroxydiphenoyl groups and/or a galloyl group, such as eugeniin, castalagin, punicalagin, pedunculagin, corilagin and geraniin, strongly interacted with SEA and inhibited toxin activity at a low concentration. These polyphenols may be used to prevent S. aureus infection and staphylococcal food poisoning.

  7. From Escherichia coli heat-stable enterotoxin to mammalian endogenous guanylin hormones

    Energy Technology Data Exchange (ETDEWEB)

    Lima, A.A.M. [Universidade Federal do Ceará, Departamento de Fisiologia e Farmacologia, Escola de Medicina, Instituto de Biomedicina, Unidade de Pesquisas Clínicas, Fortaleza, CE, Brasil, Unidade de Pesquisas Clínicas, Instituto de Biomedicina, Departamento de Fisiologia e Farmacologia, Escola de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Fonteles, M.C. [Universidade Federal do Ceará, Departamento de Fisiologia e Farmacologia, Escola de Medicina, Instituto de Biomedicina, Unidade de Pesquisas Clínicas, Fortaleza, CE, Brasil, Unidade de Pesquisas Clínicas, Instituto de Biomedicina, Departamento de Fisiologia e Farmacologia, Escola de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Universidade Estadual do Ceará, Instituto de Ciências Biomédicas, Fortaleza, CE, Brasil, Instituto de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE (Brazil)

    2014-03-03

    The isolation of heat-stable enterotoxin (STa) from Escherichia coli and cholera toxin from Vibrio cholerae has increased our knowledge of specific mechanisms of action that could be used as pharmacological tools to understand the guanylyl cyclase-C and the adenylyl cyclase enzymatic systems. These discoveries have also been instrumental in increasing our understanding of the basic mechanisms that control the electrolyte and water balance in the gut, kidney, and urinary tracts under normal conditions and in disease. Herein, we review the evolution of genes of the guanylin family and STa genes from bacteria to fish and mammals. We also describe new developments and perspectives regarding these novel bacterial compounds and peptide hormones that act in electrolyte and water balance. The available data point toward new therapeutic perspectives for pathological features such as functional gastrointestinal disorders associated with constipation, colorectal cancer, cystic fibrosis, asthma, hypertension, gastrointestinal barrier function damage associated with enteropathy, enteric infection, malnutrition, satiety, food preferences, obesity, metabolic syndrome, and effects on behavior and brain disorders such as attention deficit, hyperactivity disorder, and schizophrenia.

  8. Concerted action of sphingomyelinase and non-hemolytic enterotoxin in pathogenic Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Viktoria M Doll

    Full Text Available Bacillus cereus causes food poisoning and serious non-gastrointestinal-tract infections. Non-hemolytic enterotoxin (Nhe, which is present in most B. cereus strains, is considered to be one of the main virulence factors. However, a B. cereus ΔnheBC mutant strain lacking Nhe is still cytotoxic to intestinal epithelial cells. In a screen for additional cytotoxic factors using an in vitro model for polarized colon epithelial cells we identified B. cereus sphingomyelinase (SMase as a strong inducer of epithelial cell death. Using single and double deletion mutants of sph, the gene encoding for SMase, and nheBC in B. cereus we demonstrated that SMase is an important factor for B. cereus cytotoxicity in vitro and pathogenicity in vivo. SMase substantially complemented Nhe induced cytotoxicity in vitro. In addition, SMase but not Nhe contributed significantly to the mortality rate of larvae in vivo in the insect model Galleria mellonella. Our study suggests that the role of B. cereus SMase as a secreted virulence factor for in vivo pathogenesis has been underestimated and that Nhe and SMase complement each other significantly to cause full B. cereus virulence hence disease formation.

  9. Inhibition of biological activity of staphylococcal enterotoxin A (SEA) by apple juice and apple polyphenols.

    Science.gov (United States)

    Rasooly, Reuven; Do, Paula M; Friedman, Mendel

    2010-05-12

    The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal enterotoxin A (SEA), a single-chain protein that consists of 233 amino acid residues with a molecular weight of 27 078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, diarrhea, atopic dermatitis, arthritis, and toxic shock) syndromes. Changes of the native structural integrity may inactivate the toxin by preventing molecular interaction with cell membrane receptor sites of their host cells. In the present study, we evaluated the ability of one commercial and two freshly prepared apple juices and a commercial apple polyphenol preparation (Apple Poly) to inhibit the biological activity of SEA. Dilutions of freshly prepared apple juices and Apple Poly inhibited the biological activity of SEA without any significant cytotoxic effect on the spleen cells. Additional studies with antibody-coated immunomagnetic beads bearing specific antibodies against the toxin revealed that SEA added to apple juice appears to be largely irreversibly bound to the juice constituents. The results suggest that food-compatible and safe anti-toxin phenolic compounds can be used to inactivate SEA in vitro and possibly also in vivo, even after induction of T-cell proliferation by long-term exposure to SEA. The significance of the results for microbial food safety and human health is discussed.

  10. Evaluation of Handheld Assays for the Detection of Ricin and Staphylococcal Enterotoxin B in Disinfected Waters

    Directory of Open Access Journals (Sweden)

    Mary Margaret Wade

    2011-01-01

    Full Text Available Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs in detecting ricin and Staphylococcal Enterotoxin B (SEB in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured.

  11. Selection of staphylococcal enterotoxin B (SEB)-binding peptide using phage display technology

    International Nuclear Information System (INIS)

    Soykut, Esra Acar; Dudak, Fahriye Ceyda; Boyaci, Ismail Hakki

    2008-01-01

    In this study, peptides were selected to recognize staphylococcal enterotoxin B (SEB) which cause food intoxication and can be used as a biological war agent. By using commercial M13 phage library, single plaque isolation of 38 phages was done and binding affinities were investigated with phage-ELISA. The specificities of the selected phage clones showing high affinity to SEB were checked by using different protein molecules which can be found in food samples. Furthermore, the affinities of three selected phage clones were determined by using surface plasmon resonance (SPR) sensors. Sequence analysis was realized for three peptides showing high binding affinity to SEB and WWRPLTPESPPA, MNLHDYHRLFWY, and QHPQINQTLYRM amino acid sequences were obtained. The peptide sequence with highest affinity to SEB was synthesized with solid phase peptide synthesis technique and thermodynamic constants of the peptide-SEB interaction were determined by using isothermal titration calorimetry (ITC) and compared with those of antibody-SEB interaction. The binding constant of the peptide was determined as 4.2 ± 0.7 x 10 5 M -1 which indicates a strong binding close to that of antibody

  12. Evaluation of Potential Effects of NaCl and Sorbic Acid on Staphylococcal Enterotoxin A Formation

    Directory of Open Access Journals (Sweden)

    Nikoleta Zeaki

    2015-09-01

    Full Text Available The prophage-encoded staphylococcal enterotoxin A (SEA is recognized as the main cause of staphylococcal food poisoning (SFP, a common foodborne intoxication disease, caused by Staphylococcus aureus. Studies on the production of SEA suggest that activation of the SOS response and subsequent prophage induction affect the regulation of the sea gene and the SEA produced, increasing the risk for SFP. The present study aims to evaluate the effect of NaCl and sorbic acid, in concentrations relevant to food production, on SOS response activation, prophage induction and SEA production. The impact of stress was initially evaluated on steady state cells for a homogenous cell response. NaCl 2% was found to activate the SOS response, i.e., recA expression, and trigger prophage induction, in a similar way as the phage-inducer mitomycin C. In contrast, sorbic acid decreased the pH of the culture to a level where prophage induction was probably suppressed, even when combined with NaCl stress. The impact of previous physiological state of the bacteria was also addressed on cells pre-exposed to NaCl, and was found to potentially affect cell response upon exposure to further stress. The results obtained highlight the possible SFP-related risks arising from the use of preservatives during food processing.

  13. Inhibition of the superantigenic activities of Staphylococcal enterotoxin A by an aptamer antagonist.

    Science.gov (United States)

    Wang, Kaiyu; Wu, Dong; Chen, Zhuang; Zhang, Xianhui; Yang, Xiangyue; Yang, Chaoyong James; Lan, Xiaopeng

    2016-09-01

    Staphylococcal enterotoxin A (SEA) is an important component of Staphylococcus aureus pathogenesis. SEA induces T lymphocytes activation and proliferation, resulting in the release of a large number of inflammatory cytokines. Blocking the toxic cascade triggered by SEA may be an effective strategy for the treatment of SEA-induced diseases. Through a systematic evolution of ligands by exponential enrichment process, we obtained an aptamer (S3) that could bind SEA with both high affinity and specificity, with a Kd value 36.93 ± 7.29 nM (n = 3). This aptamer antagonist effectively inhibited SEA-mediated human peripheral blood mononuclear cells proliferation and inflammatory cytokines (IFN-γ, TNF-α, IL-2 and IL-6) secretion. Moreover, PEGylated S3 significantly reduced mortality in murine lethal toxic shock models established by lipopolysaccharide-potentiated SEA. Therefore, this novel aptamer antagonist has the potential to become a new strategy for treating S. aureus infections and SEA-induced diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Lactobacillus zeae protects Caenorhabditis elegans from enterotoxigenic Escherichia coli-caused death by inhibiting enterotoxin gene expression of the pathogen.

    Directory of Open Access Journals (Sweden)

    Mengzhou Zhou

    Full Text Available BACKGROUND: The nematode Caenorhabditis elegans has become increasingly used for screening antimicrobials and probiotics for pathogen control. It also provides a useful tool for studying microbe-host interactions. This study has established a C. elegans life-span assay to preselect probiotic bacteria for controlling K88(+ enterotoxigenic Escherichia coli (ETEC, a pathogen causing pig diarrhea, and has determined a potential mechanism underlying the protection provided by Lactobacillus. METHODOLOGY/PRINCIPAL FINDINGS: Life-span of C. elegans was used to measure the response of worms to ETEC infection and protection provided by lactic acid-producing bacteria (LAB. Among 13 LAB isolates that varied in their ability to protect C. elegans from death induced by ETEC strain JG280, Lactobacillus zeae LB1 offered the highest level of protection (86%. The treatment with Lactobacillus did not reduce ETEC JG280 colonization in the nematode intestine. Feeding E. coli strain JFF4 (K88(+ but lacking enterotoxin genes of estA, estB, and elt did not cause death of worms. There was a significant increase in gene expression of estA, estB, and elt during ETEC JG280 infection, which was remarkably inhibited by isolate LB1. The clone with either estA or estB expressed in E. coli DH5α was as effective as ETEC JG280 in killing the nematode. However, the elt clone killed only approximately 40% of worms. The killing by the clones could also be prevented by isolate LB1. The same isolate only partially inhibited the gene expression of enterotoxins in both ETEC JG280 and E. coli DH5α in-vitro. CONCLUSIONS/SIGNIFICANCE: The established life-span assay can be used for studies of probiotics to control ETEC (for effective selection and mechanistic studies. Heat-stable enterotoxins appeared to be the main factors responsible for the death of C. elegans. Inhibition of ETEC enterotoxin production, rather than interference of its intestinal colonization, appears to be the

  15. A regenerable piezoelectric immunosensor on the basis of electropolymerized polypyrrole for highly selective detection of Staphylococcal Enterotoxin A in foodstuffs

    International Nuclear Information System (INIS)

    Karaseva, Nadezhda; Ermolaeva, Tatyana

    2015-01-01

    Piezoelectric immunosensors have been developed for the determination of trace concentrations of Staphylococcal enterotoxin A (SEA) in foodstuff. Antibodies against SEA were covalently immobilized on an electropolymerized polypyrrole substrate on a gold electrode which warrants increased stability of the biolayer and sensitive detection. The calibration plot is linear in the 1–80 ng∙mL -1 SEA concentration range, the limit of detection is 0.4 ng∙mL -1 , and the time of analysis is <30 min. The sensor was successfully applied to quantify SEA in chicken meat and milk. (author)

  16. Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract.

    Science.gov (United States)

    Józefiak, D; Kierończyk, B; Rawski, M; Hejdysz, M; Rutkowski, A; Engberg, R M; Højberg, O

    2014-06-01

    The aim of the present work was to examine how different fats commonly used in the feed industry affect broiler performance, nutrient digestibility and microbial fermentation in the gastrointestinal tract of broiler chickens challenged with virulent Clostridium perfringens strains. Two experiments were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C. perfringens did not affect broiler chicken body weight gain (BWG) and mortality in either of the two experiments. The BWG was affected by dietary fat type in both experiments, indicating that the fatty acid composition of the fat source affects broiler growth performance. In particular, the inclusion of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v. 1.69) and at 42 days (1.65 v. 1.68). In both experiments apparent metabolizable energy values were affected by dietary fat type. Irrespective of the fat type present in the diet, C. perfringens challenge decreased the digesta pH in the crop and ileum, but had no effect in cecal contents. Moreover, in Experiment 1, total organic acid concentration in the ileum was two to three times lower on soybean oil diets as compared with other treatments, indicating that C. perfringens as well as

  17. Fatal Clostridium perfringens sepsis due to emphysematous gastritis and literature review.

    Science.gov (United States)

    Sarvari, Karoly Peter; Vasas, Bela; Kiss, Ildiko; Lazar, Andrea; Horvath, Istvan; Simon, Marianna; Peto, Zoltan; Urban, Edit

    2016-08-01

    A 76-year-old female patient was admitted to the Level I Emergency Department of University of Szeged with severe abdominal pain and vomiting. The clinical assessment with laboratory tests and radiological investigations confirmed severe sepsis associated with intravascular hemolysis and multiorgan failure and acute pancreatitis. On the abdominal CT, besides of other abnormalities, the presence of gas bubbles in the stomach, small intestines and liver were seen. The gastric alterations pointed to emphysematous gastritis. Despite of the medical treatment, the patient's condition quickly deteriorated and eight hours after admission the patient died. The autopsy evaluation revealed systemic infection of abdominal origin caused by gas-producing Gram-positive bacteria, and the post-mortem microbiological cultures confirmed the presence of Cloctridium perfringens in many abdominal organs. Emphysematous gastritis seemed to be the primary infectious focus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Molecular typing of toxigenic Clostridum perfringens isolated from sheep in Iran

    Directory of Open Access Journals (Sweden)

    Abdolmohammadi Khiav, L.

    2011-12-01

    Full Text Available In this research a molecular method based on polymerase chain reaction for typing of Clostridiumperfringens was developed and toxin genotypes of 64 isolates from sheep and goats in Iran weredetermined. The PCR assays were developed for detection of alpha (cpa, beta (cpb and epsilon (etxtoxin genes, allowing classification of the isolates into genotypes A B, C and D. The field isolates wereassigned to genotypes A (n=9, 14.07 %, B (n=20, 31.25%, C (n=17, 26.56% and D (n=18, 28.12%. Inthis PCR system the fragments of 900, 611 and 402 bp were amplified using specific primers for alpha, beta and epsilon toxins, respectively. The fragments were confirmed by sequencing and blasting in GenBank. The sequence alignment of the fragments showed more than 98% similarity with other related published sequences from other sources. Our results suggest that PCR genotyping is an acceptable tool for in vitro typing of C. perfringens.

  19. Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo.

    Science.gov (United States)

    Lv, You; Ye, Tao; Wang, Hui-Peng; Zhao, Jia-Ying; Chen, Wen-Jie; Wang, Xin; Shen, Chen-Xia; Wu, Yi-Bin; Cai, Yuan-Kun

    2017-01-28

    To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dose toxin (ADLT; n = 20, 10 μg), and a model + high-dose toxin (ADHT; n = 20, 20 μg) group. Mice weight, tumor formation and pathology were analyzed. Immunohistochemistry determined Ki-67 and Caspase-3 expression in normal and tumor tissues of colorectal mucosa. Recombinant BFT-2 was successfully obtained, along with its biological activity. The most obvious weight loss occurred in the AD group compared with the ADLT group (21.82 ± 0.68 vs 23.23 ± 0.91, P ADHT group (21.82 ± 0.68 vs 23.57 ± 1.06, P ADHT groups (19.75 ± 3.30 vs 6.50 ± 1.73, P ADHT group. The incidence of colorectal adenocarcinoma in both the ADHT group and the ADHT group was reduced compared to that in the AD group ( P ADHT group was 50% and 40%, respectively, both of which were lower than that found in the AD group (94.44%, P ADHT group was 45% and 55%, both of which were higher than that found in the BC group (16.67%, P < 0.05, P < 0.05). Oral administration with lower-dose biologically active recombinant BFT-2 inhibited colorectal tumorigenesis in mice.

  20. Modeling the effects of a Staphylococcal Enterotoxin B (SEB on the apoptosis pathway

    Directory of Open Access Journals (Sweden)

    Hammamieh Rasha

    2006-05-01

    Full Text Available Abstract Background The lack of detailed understanding of the mechanism of action of many biowarfare agents poses an immediate challenge to biodefense efforts. Many potential bioweapons have been shown to affect the cellular pathways controlling apoptosis 1234. For example, pathogen-produced exotoxins such as Staphylococcal Enterotoxin B (SEB and Anthrax Lethal Factor (LF have been shown to disrupt the Fas-mediated apoptotic pathway 24. To evaluate how these agents affect these pathways it is first necessary to understand the dynamics of a normally functioning apoptosis network. This can then serve as a baseline against which a pathogen perturbed system can be compared. Such comparisons can expose both the proteins most susceptible to alteration by the agent as well as the most critical reaction rates to better instill control on a biological network. Results We explore this through the modeling and simulation of the Fas-mediated apoptotic pathway under normal and SEB influenced conditions. We stimulated human Jurkat cells with an anti-Fas antibody in the presence and absence of SEB and determined the relative levels of seven proteins involved in the core pathway at five time points following exposure. These levels were used to impute relative rate constants and build a quantitative model consisting of a series of ordinary differential equations (ODEs that simulate the network under both normal and pathogen-influenced conditions. Experimental results show that cells exposed to SEB exhibit an increase in the rate of executioner caspase expression (and subsequently apoptosis of 1 hour 43 minutes (± 14 minutes, as compared to cells undergoing normal cell death. Conclusion Our model accurately reflects these results and reveals intervention points that can be altered to restore SEB-influenced system dynamics back to levels within the range of normal conditions.

  1. Effect of different ionizing radiation dose rates on the Staphylococcal enterotoxin in mechanically deboned chicken meat

    International Nuclear Information System (INIS)

    Azevedo, Heliana de; Brito, Poliana de Paula; Fukuma, Henrique Takuji; Roque, Claudio Vitor; Custodio, Wilson; Kodama, Yasko; Miya, Norma Terugo Nago; Pereira, Jose Luiz

    2009-01-01

    Samples weighing 50g each were prepared from allotments of back with skin MDCM, to the EEB contamination or not (control). Each sample of MDCM contaminated or not with EEB was conditioned in low density polyethylene bag, frozen (-18 ± 1 deg C) for one night in a tunnel and irradiated with gamma rays from 60 Co source in this state with doses of 0.0 kGy (control), 1.5 kGy (5.7 kGy.h -1 - higher dose rate, 1.8 kGy.h -1 - intermediary dose rate and 0.6 kGy.h -1 - lower dose rate) and 3.0 kGy (8.4 kGy.h - '1 - higher dose rate, 2.4 kGy.h -1 - intermediary dose rate and 0.6 kGy.h -1 - lower dose rate). Irradiated or non irradiated MDCM samples were processed to the EEB extraction, according to the VIDAS Staph enterotoxin II kit (bioMerieux) manufacturer protocol. The calculation to determinate the MDCM EEB recovery after the sample (control or irradiated) processing were carried out applying the principle of mass balance, along the whole process. Described experiment was performed in triplicate. Results showed that the irradiation process was effective to remove the MDCM EEB, to both 1.5 kGy and 3.0 kGy. According to the expected, doses of 3.0 kGy showed the highest values of MDCM EEB removal. Regarding the effect of dose rate of radiation on the removal of EEB of the MDCM, it could be observed only for samples irradiated with 1.5 kGy radiation dose; in these processing conditions, the highest value of EEB removal was obtained for samples processed with low radiation dose rate. (author)

  2. Novel Tissue Level Effects of the Staphylococcus aureus Enterotoxin Gene Cluster Are Essential for Infective Endocarditis.

    Science.gov (United States)

    Stach, Christopher S; Vu, Bao G; Merriman, Joseph A; Herrera, Alfa; Cahill, Michael P; Schlievert, Patrick M; Salgado-Pabón, Wilmara

    2016-01-01

    Superantigens are indispensable virulence factors for Staphylococcus aureus in disease causation. Superantigens stimulate massive immune cell activation, leading to toxic shock syndrome (TSS) and contributing to other illnesses. However, superantigens differ in their capacities to induce body-wide effects. For many, their production, at least as tested in vitro, is not high enough to reach the circulation, or the proteins are not efficient in crossing epithelial and endothelial barriers, thus remaining within tissues or localized on mucosal surfaces where they exert only local effects. In this study, we address the role of TSS toxin-1 (TSST-1) and most importantly the enterotoxin gene cluster (egc) in infective endocarditis and sepsis, gaining insights into the body-wide versus local effects of superantigens. We examined S. aureus TSST-1 gene (tstH) and egc deletion strains in the rabbit model of infective endocarditis and sepsis. Importantly, we also assessed the ability of commercial human intravenous immunoglobulin (IVIG) plus vancomycin to alter the course of infective endocarditis and sepsis. TSST-1 contributed to infective endocarditis vegetations and lethal sepsis, while superantigens of the egc, a cluster with uncharacterized functions in S. aureus infections, promoted vegetation formation in infective endocarditis. IVIG plus vancomycin prevented lethality and stroke development in infective endocarditis and sepsis. Our studies support the local tissue effects of egc superantigens for establishment and progression of infective endocarditis providing evidence for their role in life-threatening illnesses. In contrast, TSST-1 contributes to both infective endocarditis and lethal sepsis. IVIG may be a useful adjunct therapy for infective endocarditis and sepsis.

  3. Rhinosinusitis derived Staphylococcal enterotoxin B possibly associates with pathogenesis of ulcerative colitis

    Directory of Open Access Journals (Sweden)

    An Zi-Yuan

    2005-09-01

    Full Text Available Abstract Background During clinical practice, we noticed that some patients with both ulcerative colitis (UC and chronic rhinosinusitis (CRS showed amelioration of UC after treatment of CRS. This study was designed to identify a possible association between CRS and UC. Methods Thirty-two patients with both CRS and UC received treatment with functional endoscopic sinus surgery (FESS for CRS. Clinical symptom scores for CRS and UC, as well as serum levels of anti-Staphylococcal enterotoxin B (SEB were evaluated at week 0 and week 12. Sinus wash fluid SEB content was measured with enzyme-linked immunosorbent assay (ELISA. The surgically removed tissues were cultured to identify growth of Staphylococcus. aureus (S. aureus. Immunohistochemistry was employed to identify anti-SEB positive cells in the colonic mucosa. Colonic biopsies were obtained and incubated with SEB. Mast cell activation in the colonic mucosa in response to incubation with SEB was observed with electron microscopy and immunoassay. Results The clinical symptom scores of CRS and UC severe scores (UCSS were significantly reduced in the UC-CRS patients after FESS. The number of cultured S. aureus colonies from the surgically removed sinus mucosa significantly correlated with the decrease in UCSS. High levels of SEB were detected in the sinus wash fluids of the patients with UC-CRS. Histamine and tryptase release was significantly higher in the culture supernate in the patients with UC-CRS than the patients with UC-only and normal controls. Anti-SEB positive cells were located in the colonic mucosa. Conclusion The pathogenesis of UC in some patients may be associated with their pre-existing CRS by a mechanism of swallowing sinusitis-derived SEB. We speculate that SEB initiates inappropriate immune reactions and inflammation in the colonic mucosa that further progresses to UC.

  4. Assessment of Clostridium perfringens spore response to high hydrostatic pressure and heat with nisin.

    Science.gov (United States)

    Gao, Yulong; Qiu, Weifen; Wu, Ding; Fu, Qiang

    2011-08-01

    The elimination of spores from low-acid foods presents food-processing and food-safety challenges to high-pressure processing (HPP) developers as bacterial spores are extremely resistant to pressure. Therefore, the effects of pressure (400-800 MPa), temperature (35-95 °C), and nisin (0-496 IU/mL) on the inactivation of Clostridium perfringens AS 64701 spores at various pressure-holding times (7.5-17.5 min) were explored. A second-order polynomal equation for HPP- and nisin-induced inactivation of C. perfringens spores was constructed with response surface methodology. Experiment results showed that the experimental values were shown to be significantly in agreement with the predicted values because the adjusted determination coefficient (R (Adj)²) was 0.9708 and the level of significance was P pressure of 654 Mpa, temperature of 74 °C, pressure-holding time of 13.6 min, and nisin concentration of 328 IU/mL. The validation of the model equation for predicting the optimum response values was verified effectively by ten test points that were not used in the establishment of the model. Compared with conventional HPP techniques, the main process advantages of HPP-nisin combination sterilization in the UHT milk are, lower pressure, temperature, natural preservative (nisin), and in a shorter treatment time. The synergistic inactivation of bacteria by HPP-nisin combination is a promising and natural method to increase the efficiency and safety of high-pressure pasteurization.

  5. Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide.

    Directory of Open Access Journals (Sweden)

    Carles Gil

    Full Text Available Epsilon toxin (Etx is one of the major lethal toxins produced by Clostridium perfringens types B and D, being the causal agent of fatal enterotoxemia in animals, mainly sheep and goats. Etx is synthesized as a non-active prototoxin form (proEtx that becomes active upon proteolytic activation. Etx exhibits a cytotoxic effect through the formation of a pore in the plasma membrane of selected cell targets where Etx specifically binds due to the presence of specific receptors. However, the identity and nature of host receptors of Etx remain a matter of controversy. In the present study, the interactions between Etx and membrane lipids from the synaptosome-enriched fraction from rat brain (P2 fraction and MDCK cell plasma membrane preparations were analyzed. Our findings show that both Etx and proEtx bind to lipids extracted from lipid rafts from the two different models as assessed by protein-lipid overlay assay. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. Binding of proEtx to sulfatide, phosphatidylserine, phosphatidylinositol (3-phosphate and phosphatidylinositol (5-phosphate was detected. Removal of the sulphate groups via sulfatase treatment led to a dramatic decrease in Etx-induced cytotoxicity, but not in proEtx-GFP binding to MDCK cells or a significant shift in oligomer formation, pointing to a role of sulfatide in pore formation in rafts but not in toxin binding to the target cell membrane. These results show for the first time the interaction between Etx and membrane lipids from host tissue and point to a major role for sulfatides in C. perfringens epsilon toxin pathophysiology.

  6. Primeiro relato no Brasil de mastite necrótica bovina por Clostridium perfringens tipo A First report in Brazil of bovine necrotic mastitis due to Clostridium perfringens type A

    Directory of Open Access Journals (Sweden)

    Luciana Aramuni Gonçalves

    2006-08-01

    Full Text Available Relata-se o primeiro caso no Brasil de mastite bovina por Clostridium perfringens tipo A. O quadro clínico caracterizou-se por necrose da papila mamária e porção ventral do quarto afetado. O agente foi isolado em cultura pura e identificado como tipo A por PCR a partir do leite do quarto mamário afetado.This report describes a case of bovine mastitis due to Clostridium perfringens type A for first time in Brazil. The unical case showed necrosis of papilla mammary and ventral portion of the affected quarter. The microorganism was isolated in pure culture and identified as type A by PCR from milk of the affected mammary quarter.

  7. Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract

    DEFF Research Database (Denmark)

    Jozefiak, D; Kieronczyk, B; Rawski, M

    2014-01-01

    fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C...... were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork...... of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v...

  8. Comparison of Genotypes and Enterotoxin Genes Between Staphylococcus aureus Isolates from Blood and Nasal Colonizers in a Korean Hospital

    Science.gov (United States)

    Peck, Kyong Ran; Baek, Jin Yang; Song, Jae-Hoon

    2009-01-01

    In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness. PMID:19654937

  9. Sensitive chemiluminescence immunoassay for staphylococcal enterotoxin C1 based on the use of dye-encapsulated mesoporous silica nanoparticles

    International Nuclear Information System (INIS)

    Tao, Liang; Zhang, Chunmei; Sun, Yuanjie; Jin, Boquan; Yang, Kun; Li, Xiaohua; Zhang, Zhujun; Zhang, Jinpeng; Yan, Kuocheng

    2016-01-01

    A chemiluminescent immunoassay for the staphylococcal enterotoxin C1 (SEC1) based on the use of dye-encapsulated mesoporous silica nanoparticles (m-SiNPs) as a label is described. The dyes are retained in the m-SiNPs via strong hydrophobic interactions. The assay comprises the following steps: (a) Microplates coated with antibody against SEC1 are filled with sample upon which the SEC antigen will be bound to the surface; (b) following a washing step, secondary antibody linked to m-SiNPs (that were covalently labeled with rhodamine 6G and fluorescein) were added to form the sandwich complex; (c) after another washing step, bis(2,4,6-trichlorophenyl) oxalate, H_2O_2 and imidazole are added to generate chemiluminescence whose intensity is proportional to the number of m-SiNPs and thus to the number of antigen (SEC) molecules. It is found that the use of functionalized m-SiNPs strongly amplifies the signal. Enterotoxin SEC1 can be detected by this method in the 0.025 to 2 ng⋅mL"-"1 concentration range, the detection limit is 19 pg⋅mL"-"1 (at 3σ), and the relative standard deviation (for 11 parallel measurements at a 1 ng⋅mL"-"1 level) is 4.6 %. The use of an automated chemiluminescence analyzer further improves detection. (author)

  10. Magnetic Bead and Fluorescent Silica Nanoparticles Based Optical Immunodetection of Staphylococcal Enterotoxin B (SEB in Bottled Water

    Directory of Open Access Journals (Sweden)

    Shiva K. RASTOGI

    2009-10-01

    Full Text Available Staphylococcal enterotoxins (SEs are a major cause of food-borne diseases, most commonly SEs assayed immunologically with ELISA. An immunoassay based on fluorescein dye doped silica dioxide nanoparticles (F-SiNPs and magnetic bead (MB is described here for the detection of staphylococcal enterotoxin B (SEB. F-SiNPs have unique optical properties which make them attractive for biosensing. The water-in-oil (W/O reverse microemulsion method was used for the synthesis of F-SiNPs (~ 95 nm of diameter. The F-SiNPs were characterized using SEM, TEM and FTIR spectroscopy. The detection of SEB is preformed in PBS buffer, and bottled drinking water using sandwich immunoassay format. Target analytes were captured using MBs modified with the antigen-specific “capture” antibody, and detected using F-SiNP labeled secondary antigen-specific antibody. We report a limit of detection down to 1 ng/mL SEB spiked sample in less than 2 hr assay time using fluorocount method. This study demonstrates the bio warfare agent SEB capture by magnetic beads and detection using F-SiNPs.

  11. The CpAL quorum sensing system regulates production of hemolysins CPA and PFO to build Clostridium perfringens biofilms.

    Science.gov (United States)

    Vidal, Jorge E; Shak, Joshua R; Canizalez-Roman, Adrian

    2015-06-01

    Clostridium perfringens strains produce severe diseases, including myonecrosis and enteritis necroticans, in humans and animals. Diseases are mediated by the production of potent toxins that often damage the site of infection, e.g., skin epithelium during myonecrosis. In planktonic cultures, the regulation of important toxins, such as CPA, CPB, and PFO, is controlled by the C. perfringens Agr-like (CpAL) quorum sensing (QS) system. Strains also encode a functional LuxS/AI-2 system. Although C. perfringens strains form biofilm-like structures, the regulation of biofilm formation is poorly understood. Therefore, our studies investigated the role of CpAL and LuxS/AI-2 QS systems and of QS-regulated factors in controlling the formation of biofilms. We first demonstrate that biofilm production by reference strains differs depending on the culture medium. Increased biomass correlated with the presence of extracellular DNA in the supernatant, which was released by lysis of a fraction of the biofilm population and planktonic cells. Whereas ΔagrB mutant strains were not able to produce biofilms, a ΔluxS mutant produced wild-type levels. The transcript levels of CpAL-regulated cpa and pfoA genes, but not cpb, were upregulated in biofilms compared to planktonic cultures. Accordingly, Δcpa and ΔpfoA mutants, in type A (S13) or type C (CN3685) backgrounds, were unable to produce biofilms, whereas CN3685Δcpb made wild-type levels. Biofilm formation was restored in complemented Δcpa/cpa and ΔpfoA/pfoA strains. Confocal microscopy studies further detected CPA partially colocalizing with eDNA on the biofilm structure. Thus, CpAL regulates biofilm formation in C. perfringens by increasing levels of certain toxins required to build biofilms. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. The CpAL Quorum Sensing System Regulates Production of Hemolysins CPA and PFO To Build Clostridium perfringens Biofilms

    Science.gov (United States)

    Shak, Joshua R.; Canizalez-Roman, Adrian

    2015-01-01

    Clostridium perfringens strains produce severe diseases, including myonecrosis and enteritis necroticans, in humans and animals. Diseases are mediated by the production of potent toxins that often damage the site of infection, e.g., skin epithelium during myonecrosis. In planktonic cultures, the regulation of important toxins, such as CPA, CPB, and PFO, is controlled by the C. perfringens Agr-like (CpAL) quorum sensing (QS) system. Strains also encode a functional LuxS/AI-2 system. Although C. perfringens strains form biofilm-like structures, the regulation of biofilm formation is poorly understood. Therefore, our studies investigated the role of CpAL and LuxS/AI-2 QS systems and of QS-regulated factors in controlling the formation of biofilms. We first demonstrate that biofilm production by reference strains differs depending on the culture medium. Increased biomass correlated with the presence of extracellular DNA in the supernatant, which was released by lysis of a fraction of the biofilm population and planktonic cells. Whereas ΔagrB mutant strains were not able to produce biofilms, a ΔluxS mutant produced wild-type levels. The transcript levels of CpAL-regulated cpa and pfoA genes, but not cpb, were upregulated in biofilms compared to planktonic cultures. Accordingly, Δcpa and ΔpfoA mutants, in type A (S13) or type C (CN3685) backgrounds, were unable to produce biofilms, whereas CN3685Δcpb made wild-type levels. Biofilm formation was restored in complemented Δcpa/cpa and ΔpfoA/pfoA strains. Confocal microscopy studies further detected CPA partially colocalizing with eDNA on the biofilm structure. Thus, CpAL regulates biofilm formation in C. perfringens by increasing levels of certain toxins required to build biofilms. PMID:25824838

  13. Mechanisms of antibacterial action of Quinoxaline 1,4-di-N-oxides against Clostridium perfringens and Brachyspira hyodysenteriae

    Directory of Open Access Journals (Sweden)

    Fanfan Xu

    2016-12-01

    Full Text Available Quinoxaline 1,4-di-N-oxides (QdNOs are a class of bioreductive compounds, however their antibacterial mechanisms are still unclarified. The aim of this study was to assess the ability of two representative QdNO drugs, cyadox (CYA and olaquindox (OLA, to produce reactive oxide species (ROS in Gram-positive anaerobe Clostridium perfringens CVCC1125 and Gram-negative anaerobe Brachyspira hyodysenteriae B204. In addition, the effects of QdNOs on the integrity of bacterial cell walls and membranes as well as the morphological alterations and DNA oxidative damage in C. perfringens and B. hyodysenteriae were analyzed. It was demonstrated that under anaerobic conditions, QdNOs were metabolized into the reduced products which did not show any antibacterial activity. A significant dose-related increase of intracellular ROS level and intracellular hydroxyl radicals were evident in bacteria exposed to QdNOs. The result of biochemical assay showed that the cell walls and membranes of the bacteria treated with QdNOs were damaged. After exposure to 1/2MIC to 4MIC of CYA and OLA, C. perfringens and B. hyodysenteriae became elongated and filamentous. Morphological observation with scanning and transmission electron microscopes revealed rupture, loss of cytoplasmic material and cell lysis in QdNO-treated bacteria, indicating serious damage of cells. There was an increase of 8-OHdG in the two strains treated by QdNOs, but it was lower in Gram-positive than in Gram-negative bacteria. Agarose gel electrophoresis showed the degradation of chromosomal DNA in both of the two anaerobes treated by QdNOs. The results suggest that QdNOs may kill C. perfringens and B. hyodysenteriae via the generation of ROS and hydroxyl radicals from the bacterial metabolism of QdNOs, which cause oxidative damage in bacteria under anaerobic conditions.

  14. Decontamination of Clostridium perfringens and Salmonella spp. in Thai Fermented Fish (Pla-ra) by Gamma Radiation

    International Nuclear Information System (INIS)

    Prakhongsil, P.; Phianphak, W.; Malakrong, A.; Komolamisra, C.

    2014-01-01

    Gamma radiation can be applied as a decontamination method to eliminate microorganisms in fermented food. In this study, samples of Thai fermented fish were evaluated for microbiological and hygienic qualities and then exposed to gamma irradiation. Prior to irradiation, Salmonella spp. and Clostridium perfringens were detected and the results were found contaminated in five samples from twenty-six of Thai fermented fish samples ; Nile tilapia fish (Oreochromisniloticus), bighead carp fish (Aristichthys nobilis) and common snakehead fish (Channa striata) using VIDAS Salmonella Easy SLM assay and standard conventional assay for C. perfringens. For detecting of living parasites helminths, fifteen samples were assayed for liver fluke (Opisthorchis viverrini) and Gnathostoma spinigerum, but neither was found. When exposed to gamma irradiation, results showed that the minimum dose of 2.70 kGy could sufficiently eliminate Salmonella spp. from fermented Nile tilapia fish (Oreochromis nioloticus), whereas a higher dose of 6.16 kGy was required to reduce C. perfringens from130 CFU/g and 10 CFU/g to less than 10 CFU/g in fermented Nile tilapia fish and common snakehead fish (Channa striata) fish.

  15. Cloning, recombinant production, crystallization and preliminary X-ray diffraction studies of a family 84 glycoside hydrolase from Clostridium perfringens

    International Nuclear Information System (INIS)

    Ficko-Blean, Elizabeth; Boraston, Alisdair B.

    2005-01-01

    Crystallization of a family 84 glycoside hydrolase, a putative virulence factor, secreted by C. perfringens is reported. Clostridium perfringens is a ubiquitous environmental organism that is capable of causing a variety of diseases in mammals, including gas gangrene and necrotic enteritis in humans. The activity of a secreted hyaluronidase, attributed to the NagH protein, contributes to the pathogenicity of this organism. The family 84 catalytic module of one of the three homologues of NagH found in C. perfringens (ATCC 13124) has been cloned. The 69 kDa catalytic module of NagJ, here called GH84C, was overproduced in Escherichia coli and purified by immobilized metal-affinity chromatography (IMAC). Crystals belonging to space group I222 or I2 1 2 1 2 1 with unit-cell parameters a = 130.39, b = 150.05, c = 155.43 Å were obtained that diffracted to 2.1 Å. Selenomethionyl crystals have also been produced, leading to the possibility of solving the phase problem by MAD using synchrotron radiation

  16. Distribution of sewage pollution around a maritime Antarctic research station indicated by faecal coliforms, Clostridium perfringens and faecal sterol markers

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Kevin A.; Thompson, Anu

    2004-02-01

    This study describes the distribution of sewage pollution markers (faecal coliforms, Clostridium perfringens and faecal sterols) in seawater and marine sediments around Rothera Research Station, Antarctic Peninsula. Untreated sewage waste has been released from this site since 1975, creating the potential for long-term contamination of the benthic environment. Faecal coliform concentrations in seawater reached background levels within 300 m of the outfall. In sediment cores, both C. perfringens and faecal coliform concentrations declined with distance from the outfall, though C. perfringens persisted at greater depths in the sediment. High concentrations of 5{beta}(H)-cholestan-3{beta}-ol (coprostanol) relative to the corresponding 5{alpha}-epimer (cholestanol), indicative of sewage pollution, were only found in sediments within 200 m of the sewage outfall. This study has shown that sewage contamination is limited to the immediate vicinity of the sewage outfall. Nevertheless, a sewage treatment plant was installed in February 2003 to reduce this contamination further. - Sewage contamination of seawater and marine sediments near Rothera Research Station (Antarctic Peninsula) was limited to the immediate vicinity of the outfall.

  17. Distribution of sewage pollution around a maritime Antarctic research station indicated by faecal coliforms, Clostridium perfringens and faecal sterol markers

    International Nuclear Information System (INIS)

    Hughes, Kevin A.; Thompson, Anu

    2004-01-01

    This study describes the distribution of sewage pollution markers (faecal coliforms, Clostridium perfringens and faecal sterols) in seawater and marine sediments around Rothera Research Station, Antarctic Peninsula. Untreated sewage waste has been released from this site since 1975, creating the potential for long-term contamination of the benthic environment. Faecal coliform concentrations in seawater reached background levels within 300 m of the outfall. In sediment cores, both C. perfringens and faecal coliform concentrations declined with distance from the outfall, though C. perfringens persisted at greater depths in the sediment. High concentrations of 5β(H)-cholestan-3β-ol (coprostanol) relative to the corresponding 5α-epimer (cholestanol), indicative of sewage pollution, were only found in sediments within 200 m of the sewage outfall. This study has shown that sewage contamination is limited to the immediate vicinity of the sewage outfall. Nevertheless, a sewage treatment plant was installed in February 2003 to reduce this contamination further. - Sewage contamination of seawater and marine sediments near Rothera Research Station (Antarctic Peninsula) was limited to the immediate vicinity of the outfall

  18. Presence of Classical Enterotoxin Genes, agr Typing, Antimicrobial Resistance, and Genetic Diversity of Staphylococcus aureus from Milk of Cows with Mastitis in Southern Brazil.

    Science.gov (United States)

    Kroning, Isabela S; Iglesias, Mariana A; Mendonça, Karla S; Lopes, Graciela V; Silva, Wladimir P

    2018-05-01

    Staphylococcus aureus is a common causative agent of bovine mastitis in dairy cows and commonly associated with foodborne disease outbreaks. The aim of this study was to evaluate the presence of enterotoxin genes, agr typing, antimicrobial resistance, and genetic diversity of S. aureus isolated from milk of cows with mastitis in dairy farms from southern Brazil. Results showed that 7 (22.6%) of 31 S. aureus isolates were positive for enterotoxin genes. Specifically, the genes encoding for enterotoxins A ( n = 4), C ( n = 2), and B ( n = 1) were detected. Isolates belonging to the agr group III (10 of 31, 32.2%) and agr group I (7 of 31, 22.5%) were the most common. To our knowledge, this is the first report of both agr I and III in the same S. aureus isolate from milk of cows with bovine mastitis. The antimicrobial resistance test showed that 54% of the isolates were multiresistant to antimicrobial agents. The macrorestriction analysis produced 16 different major SmaI pulsed-field gel electrophoresis patterns, with up to two subpatterns. Moreover, the presence of some S. aureus clones in a distinct area was observed. Although this study characterized a limited number of S. aureus isolates, the presence of classical enterotoxin genes and resistance to multiple antimicrobial agents reinforces the importance of this microorganism to animal and human health. In addition, similar genetic profiles have been identified in distinct geographic areas, suggesting clonal dissemination of S. aureus in dairy herds from southern Brazil.

  19. Detection of coding genes for enterotoxins in Bacillus cereus by PCR and their products by BCET-RPLA and ELISA Assay

    Directory of Open Access Journals (Sweden)

    Marcela Vyletělová

    2010-01-01

    Full Text Available Determination of enterotoxin production, diarrhoeal and emetic gene identification was studied in 41 Bacillus cereus strains isolated from raw cows’ and raw goats’ milk, pasteurized milk, dairy products during technological processing and from dairy plant equipment. Presence of enterotoxins was detected by BCET-RPLA (HBL and ELISA immunoassay (NHE. Gene identification (nheA, nheB, nheC, hblA, hblC, hblD, bceT, cytK-1, cytK-2, entFM and ces was achieved by means of PCR. Enterotoxin HBL was detected in 32 strains, enterotoxin NHE in all 41 strains. Presence of all three genes nheA, nheB and nheC was confirmed in 40 strains and genes hblA, hblC and hblD in 29 strains. Comparison of used methods was as follow: 1 BCET-RPLA (which detects L2 component and PCR (positive or negative all three hblA, hblC and hblD gene detection were identical in 30 (73%; 2 ELISA (NheA and PCR (all three nheC, nheB and nheA gene expression were identical in 40 (98% cases isolated strains.

  20. Enterotoxin Producing Ability And Antimicrobial Susceptibility Of Coagulase-Negative Staphylococci Isolated From Goat Milk Cheese And Salted Yoghurt In Turkey

    Directory of Open Access Journals (Sweden)

    S. Pehlivanlar Onen

    2017-10-01

    Full Text Available The aim of this study was to determine enterotoxin producing ability and antimicrobial susceptibility of coagulase negative staphylococci CNS in goats bulk milk cheese and salted yoghurt. CNS strains were identified by using GP card in VITEK 2 system. The presence of enterotoxins was determined by enzyme immunoassay test by using RIDASCREEN test kit. Antibiotic susceptibility in CNS strains was detected by using AST-P640 card in VITEK 2 system. A total of 100 CNS strains were isolated in 22 55 bulk milk samples and in 23 57.5 cheese samples. Staphylococcus spp. could not be isolated from salted yoghurt samples. The most encountered species were S. caprae 51.9 S. chromogenes 11.5 and S. xylosus 9.6 from milk samples and S. saprophyticus 60.4 S. xylosus 12.5 and S. haemolyticus 8.3 from cheese samples. Four CNS strains 4 isolated from samples were capable of producing enterotoxin. While all isolates were resistant to at least one antibiotic 74 of CNS strains showed resistance to two or more antibiotics. Enterotoxin production ability and high antibiotic resistance of the CNS strains isolated from goat bulk milk and cheese can lead to a risk for public health.

  1. Noncontiguous Finished Genome Sequence of Staphylococcus aureus KLT6, a Staphylococcal Enterotoxin B-Positive Strain Involved in a Food Poisoning Outbreak in Switzerland

    Science.gov (United States)

    Tobes, Raquel; Manrique, Marina; Brozynska, Marta; Stephan, Roger; Pareja, Eduardo

    2013-01-01

    We present the first complete genome sequence of a Staphylococcus aureus strain assigned to clonal complex 12. The strain was isolated in a food poisoning outbreak due to contaminated potato salad in Switzerland in 2009, and it produces staphylococcal enterotoxin B. PMID:23704175

  2. Growth and enterotoxin production of Staphylococcus aureus during the manufacture and ripening of Camembert-type cheeses from raw goats' milk.

    Science.gov (United States)

    Meyrand, A; Boutrand-Loei, S; Ray-Gueniot, S; Mazuy, C; Gaspard, C E; Jaubert, G; Perrin, G; Lapeyre, C; Vernozy-Rozand, C

    1998-09-01

    Tests were carried out to determine the effect of manufacturing procedures for a Camembert-type cheese from raw goats' milk on the growth and survival of Staphylococcus aureus organisms added to milk at the start of the process, and to study the possible presence of staphylococcal enterotoxin A in these cheeses. The initial staphylococcal counts were, respectively, 2, 3, 4, 5 and 6 log cfu ml-1. Cheese was prepared following the industrial specifications and ripened for 41 d. Detection of enterotoxins was done by the Vidas SET test and by an indirect double-sandwich ELISA technique using antienterotoxin monoclonal antibodies. Generally, numbers of microbes increased at a similar rate during manufacture in all cheeses until salting. During the ripening period, the aerobic plate count population and Staph. aureus levels remained stable and high. There was an approximately 1 log reduction of Staph. aureus in cheeses made with an initial inoculum of Staph. aureus greater than 10(3) cfu ml-1 at the end of the ripening period (41 d) compared with the count at 22 h. The level of staphylococcal enterotoxin A recovered varied from 1 to 3.2 ng g-1 of cheese made with an initial population of 10(3)-10(6) cfu ml-1. No trace of enterotoxin A was detected in cheeses made with the lowest Staph. aureus inoculum used in this study.

  3. Detection of enterotoxins produced by B. cereus through PCR analysis of ground and roasted coffee samples in Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Cyllene de Matos Ornelas da Cunha Corrêa de Souza

    2011-06-01

    Full Text Available Coffee is one of the most appreciated drinks in the world. Coffee ground is obtained from the fruit of a small plant that belongs to the genus Coffea. Coffea arabica and Coffea canephora robusta are the two most commercially important species. They are more commonly known as arabica and robusta, respectively. Two-thirds of Coffea arabica plants are grown in South and Central America, and Eastern Africa - the place of origin for this coffee species. Contamination by microorganisms has been a major matter affecting coffee quality in Brazil, mainly due to the harvesting method adopted. Brazilian harvests are based on fruits collected from the ground mixed with those that fall on collection cloths. As the Bacillus cereus bacterium frequently uses the soil as its environmental reservoir, it is easily capable of becoming a contaminant. This study aimed to evaluate the contamination and potential of B. cereus enterotoxin genes encoding the HBL and NHE complexes, which were observed in strains of ground and roasted coffee samples sold in Rio de Janeiro. The PCR (Polymerase Chain Reaction results revealed high potential of enterotoxin production in the samples. The method described by Speck (1984 was used for the isolation of contaminants. The investigation of the potential production of enterotoxins through isolates of the microorganism was performed using the B. cereus enterotoxin Reverse Passive Latex Agglutination test-kit (BCET-RPLA, Oxoid, according to the manufacturer's instructions. The potential of enterotoxin production was investigated using polymerase chain reaction (PCR methods for hblA, hblD and hblC genes (encoding hemolysin HBL and for nheA, nheB and nheC genes (encoding non-hemolytic enterotoxin - NHE. Of all the 17 strains, 100% were positive for at least 1 enterotoxin gene; 52.9% (9/17 were positive for the 3 genes encoding the HBL complex; 35.3% (6/17 were positive for the three NHE encoding genes; and 29.4% (5/17 were positive for

  4. Acetic acid increases the phage-encoded enterotoxin A expression in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    da Silva Ayla

    2010-05-01

    Full Text Available Abstract Background The effects of acetic acid, a common food preservative, on the bacteriophage-encoded enterotoxin A (SEA expression and production in Staphylococcus aureus was investigated in pH-controlled batch cultures carried out at pH 7.0, 6.5, 6.0, 5.5, 5.0, and 4.5. Also, genomic analysis of S. aureus strains carrying sea was performed to map differences within the gene and in the temperate phage carrying sea. Results The sea expression profile was similar from pH 7.0 to 5.5, with the relative expression peaking in the transition between exponential and stationary growth phase and falling during stationary phase. The levels of sea mRNA were below the detection limit at pH 5.0 and 4.5, confirmed by very low SEA levels at these pH values. The level of relative sea expression at pH 6.0 and 5.5 were nine and four times higher, respectively, in the transitional phase than in the exponential growth phase, compared to pH 7.0 and pH 6.5, where only a slight increase in relative expression in the transitional phase was observed. Furthermore, the increase in sea expression levels at pH 6.0 and 5.5 were observed to be linked to increased intracellular sea gene copy numbers and extracellular sea-containing phage copy numbers. The extracellular SEA levels increased over time, with highest levels produced at pH 6.0 in the four growth phases investigated. Using mitomycin C, it was verified that SEA was at least partially produced as a consequence of prophage induction of the sea-phage in the three S. aureus strains tested. Finally, genetic analysis of six S. aureus strains carrying the sea gene showed specific sea phage-groups and two versions of the sea gene that may explain the different sea expression and production levels observed in this study. Conclusions Our findings suggest that the increased sea expression in S. aureus caused by acetic acid induced the sea-encoding prophage, linking SEA production to the lifecycle of the phage.

  5. Staphylococcal enterotoxin-specific IgE antibodies in atopic dermatitis.

    Science.gov (United States)

    Ide, Fumihito; Matsubara, Tomoyo; Kaneko, Miho; Ichiyama, Takashi; Mukouyama, Tokuko; Furukawa, Susumu

    2004-06-01

    The authors clarified the clinical significance of the measurement of serum concentrations of specific IgE antibodies to staphylococcal enterotoxin (SE) A- and SEB in atopic dermatitis (AD). The serum concentrations of SEA- and SEB-specific IgE antibodies in 140 pediatric patients with AD were measured with an immuno CAP -radioallergosorbent test system (RAST). To check the cross-reaction of specific IgE antibodies to SEA/SEB and other allergens, the CAP RAST fluorescent enzyme immunoassay inhibition test was performed. Forty-seven patients (33.6%) tested positive for either SEA- or SEB-specific IgE antibodies. School children showed higher positive rates of SEA/SEB-specific IgE antibodies than infants or young children. The patients with severe AD and those with exacerbation of symptoms in summer, had higher positive rates of SEA/SEB-specific IgE antibodies than patients with mild AD or those with exacerbation in winter. In addition, the positive rates of specific IgE antibodies to both dog-dander and cat-dander were higher in patients with positive SEA/SEB-specific IgE antibodies than in patients with negative ones. No cross-reactions occurred among specific IgE antibodies to SEA/SEB and dog/cat dander with one patient's serum, which had positive IgE-specific antibodies against cat/dog dander and SEA/SEB. The positive rate of SEA/SEB-specific IgE antibodies in the patients with dogs and/or cats as pets was 48.4%, which was higher than in those with no pets. Atopic dermatitis patients who exhibit high positive rates of SEA/SEB-specific IgE antibodies were found to be school children, severe cases, cases with high serum concentrations of total IgE, cases with exacerbation in summer, and cases with dogs and/or cats as pets. The measurement of serum concentrations of specific IgE antibodies to SEA and SEB, thus has some value for evaluating AD patients.

  6. Parenteral adjuvant potential of recombinant B subunit of Escherichia coli heat-labile enterotoxin

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Pouey da Cunha

    Full Text Available BACKGROUND The B subunit of Escherichia coli heat-labile enterotoxin (LTB is a potent mucosal immune adjuvant. However, there is little information about LTB's potential as a parenteral adjuvant. OBJECTIVES We aimed at evaluating and better understanding rLTB's potential as a parenteral adjuvant using the fused R1 repeat of Mycoplasma hyopneumoniae P97 adhesin as an antigen to characterise the humoral immune response induced by this construct and comparing it to that generated when aluminium hydroxide is used as adjuvant instead. METHODS BALB/c mice were immunised intraperitoneally with either rLTBR1 or recombinant R1 adsorbed onto aluminium hydroxide. The levels of systemic anti-rR1 antibodies (total Ig, IgG1, IgG2a, and IgA were assessed by enzyme-linked immunosorbent assay (ELISA. The ratio of IgG1 and IgG2a was used to characterise a Th1, Th2, or mixed Th1/Th2 immune response. FINDINGS Western blot confirmed rR1, either alone or fused to LTB, remained antigenic; anti-cholera toxin ELISA confirmed that LTB retained its activity when expressed in a heterologous system. Mice immunised with the rLTBR1 fusion protein produced approximately twice as much anti-rR1 immunoglobulins as mice vaccinated with rR1 adsorbed onto aluminium hydroxide. Animals vaccinated with either rLTBR1 or rR1 adsorbed onto aluminium hydroxide presented a mixed Th1/Th2 immune response. We speculate this might be a result of rR1 immune modulation rather than adjuvant modulation. Mice immunised with rLTBR1 produced approximately 1.5-fold more serum IgA than animals immunised with rR1 and aluminium hydroxide. MAIN CONCLUSIONS The results suggest that rLTB is a more powerful parenteral adjuvant than aluminium hydroxide when administered intraperitoneally as it induced higher antibody titres. Therefore, we recommend that rLTB be considered an alternative adjuvant, even if different administration routes are employed.

  7. Staphylococcal enterotoxin A regulates bone marrow granulocyte trafficking during pulmonary inflammatory disease in mice

    Energy Technology Data Exchange (ETDEWEB)

    Takeshita, W.M.; Gushiken, V.O.; Ferreira-Duarte, A.P.; Pinheiro-Torres, A.S.; Roncalho-Buck, I.A. [Department of Biology and Physiology, Faculty of Medicine of Jundiai (FMJ), Jundiai, SP (Brazil); Squebola-Cola, D.M.; Mello, G.C.; Anhê, G.F.; Antunes, E. [Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP (Brazil); DeSouza, I.A., E-mail: ivanidesouza@uol.com.br [Department of Biology and Physiology, Faculty of Medicine of Jundiai (FMJ), Jundiai, SP (Brazil)

    2015-09-15

    Pulmonary neutrophil infiltration produced by Staphylococcal enterotoxin A (SEA) airway exposure is accompanied by marked granulocyte accumulation in bone marrow (BM). Therefore, the aim of this study was to investigate the mechanisms of BM cell accumulation, and trafficking to circulating blood and lung tissue after SEA airway exposure. Male BALB/C mice were intranasally exposed to SEA (1 μg), and at 4, 12 and 24 h thereafter, BM, circulating blood, bronchoalveolar lavage (BAL) fluid and lung tissue were collected. Adhesion of BM granulocytes and flow cytometry for MAC-1, LFA1-α and VLA-4 and cytokine and/or chemokine levels were assayed after SEA-airway exposure. Prior exposure to SEA promoted a marked PMN influx to BAL and lung tissue, which was accompanied by increased counts of immature and/or mature neutrophils and eosinophils in BM, along with blood neutrophilia. Airway exposure to SEA enhanced BM neutrophil MAC-1 expression, and adhesion to VCAM-1 and/or ICAM-1-coated plates. Elevated levels of GM-CSF, G-CSF, INF-γ, TNF-α, KC/CXCL-1 and SDF-1α were detected in BM after SEA exposure. SEA exposure increased production of eosinopoietic cytokines (eotaxin and IL-5) and BM eosinophil VLA-4 expression, but it failed to affect eosinophil adhesion to VCAM-1 and ICAM-1. In conclusion, BM neutrophil accumulation after SEA exposure takes place by integrated action of cytokines and/or chemokines, enhancing the adhesive responses of BM neutrophils and its trafficking to lung tissues, leading to acute lung injury. BM eosinophil accumulation in SEA-induced acute lung injury may occur via increased eosinopoietic cytokines and VLA-4 expression. - Highlights: • Airway exposure to SEA causes acute lung inflammation. • SEA induces accumulation of bone marrow (BM) in immature and mature neutrophils. • SEA increases BM granulocyte or BM PMN adhesion to ICAM-1 and VCAM-1, and MAC-1 expression. • SEA induces BM elevations of CXCL-1, INF-γ, TNF-α, GM-CSF, G-CSF and

  8. Staphylococcal enterotoxin A regulates bone marrow granulocyte trafficking during pulmonary inflammatory disease in mice

    International Nuclear Information System (INIS)

    Takeshita, W.M.; Gushiken, V.O.; Ferreira-Duarte, A.P.; Pinheiro-Torres, A.S.; Roncalho-Buck, I.A.; Squebola-Cola, D.M.; Mello, G.C.; Anhê, G.F.; Antunes, E.; DeSouza, I.A.

    2015-01-01

    Pulmonary neutrophil infiltration produced by Staphylococcal enterotoxin A (SEA) airway exposure is accompanied by marked granulocyte accumulation in bone marrow (BM). Therefore, the aim of this study was to investigate the mechanisms of BM cell accumulation, and trafficking to circulating blood and lung tissue after SEA airway exposure. Male BALB/C mice were intranasally exposed to SEA (1 μg), and at 4, 12 and 24 h thereafter, BM, circulating blood, bronchoalveolar lavage (BAL) fluid and lung tissue were collected. Adhesion of BM granulocytes and flow cytometry for MAC-1, LFA1-α and VLA-4 and cytokine and/or chemokine levels were assayed after SEA-airway exposure. Prior exposure to SEA promoted a marked PMN influx to BAL and lung tissue, which was accompanied by increased counts of immature and/or mature neutrophils and eosinophils in BM, along with blood neutrophilia. Airway exposure to SEA enhanced BM neutrophil MAC-1 expression, and adhesion to VCAM-1 and/or ICAM-1-coated plates. Elevated levels of GM-CSF, G-CSF, INF-γ, TNF-α, KC/CXCL-1 and SDF-1α were detected in BM after SEA exposure. SEA exposure increased production of eosinopoietic cytokines (eotaxin and IL-5) and BM eosinophil VLA-4 expression, but it failed to affect eosinophil adhesion to VCAM-1 and ICAM-1. In conclusion, BM neutrophil accumulation after SEA exposure takes place by integrated action of cytokines and/or chemokines, enhancing the adhesive responses of BM neutrophils and its trafficking to lung tissues, leading to acute lung injury. BM eosinophil accumulation in SEA-induced acute lung injury may occur via increased eosinopoietic cytokines and VLA-4 expression. - Highlights: • Airway exposure to SEA causes acute lung inflammation. • SEA induces accumulation of bone marrow (BM) in immature and mature neutrophils. • SEA increases BM granulocyte or BM PMN adhesion to ICAM-1 and VCAM-1, and MAC-1 expression. • SEA induces BM elevations of CXCL-1, INF-γ, TNF-α, GM-CSF, G-CSF and

  9. Cloud point extraction coupled with microwave-assisted back-extraction (CPE-MABE) for determination of Eszopiclone (Z-drug) using UV-Visible, HPLC and mass spectroscopic (MS) techniques: Spiked and in vivo analysis.

    Science.gov (United States)

    Kori, Shivpoojan; Parmar, Ankush; Goyal, Jony; Sharma, Shweta

    2018-02-01

    A procedure for the determination of Eszopiclone (ESZ) from complex matrices i.e. in vitro (spiked matrices), as well as in vivo (mice model) was developed using cloud point extraction coupled with microwave-assisted back-extraction (CPE-MABE). Analytical measurements have been carried using UV-Visible, HPLC and MS techniques. The proposed method has been validated according to ICH guidelines and legitimate reproducible and reliability of protocol is assessed through intraday and inter-day precision UV-Visible techniques, corresponding to assessed linearity range. The coaservate phase in CPE was back extracted under microwaves exposure, with isooctane at pre-concentration factor ~50 when 5mL of sample solution was pre-concentrated to 0.1mL. Under optimized conditions i.e. Aqueous-Triton X-114 4% (w/v), pH4.0, NaCl 4% (w/v) and equilibrium temperature of 45°C for 20min, average extraction recovery has been obtained between 89.8 and 99.2% and 84.0-99.2% from UV-Visible and HPLC analysis, respectively. The method has been successfully applied to the pharmacokinetic estimation (post intraperitoneal administration) of ESZ in mice. MS analysis precisely depicted the presence of active N‑desmethyl zopiclone in impales as well as in mice plasma. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Exposure to β-lactams results in the alteration of penicillin-binding proteins in Clostridium perfringens.

    Science.gov (United States)

    Park, Miseon; Rafii, Fatemeh

    2017-06-01

    Clostridium perfringens causes a variety of mild to severe infections in humans and other animals. A decrease in the affinity of penicillin-binding protein (PBP) transpeptidases for β-lactams is considered one of the mechanisms of β-lactam resistance in bacteria. Two strains of C. perfringens isolated from bovines and one isolated from a chicken, which had decreased susceptibility to β-lactams, had variations in the amino acid sequences of the central penicillin-binding regions of the PBPs. β-Lactam-resistant mutants of another C. perfringens strain, ATCC 13124, were selected in vitro to determine the effects of exposure to β-lactams on the PBP genes. Cultures of the wild type rapidly developed resistance to penicillin G, cephalothin and ceftriaxone. The susceptibilities of all of the selected mutants to some other β-lactams also decreased. The largest PBP found in C. perfringens, CPF_2395, appeared to be the primary target of all three drugs. Strain resistant to penicillin G had mutation resulting in the substitution of one amino acid within the central penicillin-binding/transpeptidase domain, but the ceftrioxane and cephalothin-resistant strains had mutations resulting in the substitution of two amino acids in this region. The cephalothin-resistant mutant also had additional mutations in the CPF_0340 and CPF_2218 genes in this critical region. No other mutations were observed in the three other PBPs of the in vitro resistant mutants. Resistance development also altered the growth rate and cell morphology of the mutants, so in addition to the PBPs, some other genes, including regulatory genes, may have been affected during the interaction with β-lactam antibiotics. This is the first study showing the effects of β-lactam drugs on the substitution of amino acids in PBPs of C. perfringens and points to the need for studies to detect other unknown alterations affecting the physiology of resistant strains. Published by Elsevier Ltd.

  11. Recurring Necrotic Enteritis Outbreaks in Commercial Broiler Chicken Flocks Strongly Influence Toxin Gene Carriage and Species Richness in the Resident Clostridium perfringens Population

    Science.gov (United States)

    Gaucher, Marie-Lou; Perron, Gabriel G.; Arsenault, Julie; Letellier, Ann; Boulianne, Martine; Quessy, Sylvain

    2017-01-01

    Extensive use of antibiotic growth promoters (AGPs) in food animals has been questioned due to the globally increasing problem of antibiotic resistance. For the poultry industry, digestive health management following AGP withdrawal in Europe has been a challenge, especially the control of necrotic enteritis. Much research work has focused on gut health in commercial broiler chicken husbandry. Understanding the behavior of Clostridium perfringens in its ecological niche, the poultry barn, is key to a sustainable and cost-effective production in the absence of AGPs. Using polymerase chain reaction and pulsed-field gel electrophoresis, we evaluated how the C. perfringens population evolved in drug-free commercial broiler chicken farms, either healthy or affected with recurring clinical necrotic enteritis outbreaks, over a 14-month period. We show that a high genotypic richness was associated with an increased risk of clinical necrotic enteritis. Also, necrotic enteritis-affected farms had a significant reduction of C. perfringens genotypic richness over time, an increase in the proportion of C. perfringens strains harboring the cpb2 gene, the netB gene, or both. Thus, necrotic enteritis occurrence is correlated with the presence of an initial highly diverse C. perfringens population, increasing the opportunity for the selective sweep of particularly virulent genotypes. Disease outbreaks also appear to largely influence the evolution of this bacterial species in poultry farms over time. PMID:28567032

  12. Recurring Necrotic Enteritis Outbreaks in Commercial Broiler Chicken Flocks Strongly Influence Toxin Gene Carriage and Species Richness in the Resident Clostridium perfringens Population

    Directory of Open Access Journals (Sweden)

    Marie-Lou Gaucher

    2017-05-01

    Full Text Available Extensive use of antibiotic growth promoters (AGPs in food animals has been questioned due to the globally increasing problem of antibiotic resistance. For the poultry industry, digestive health management following AGP withdrawal in Europe has been a challenge, especially the control of necrotic enteritis. Much research work has focused on gut health in commercial broiler chicken husbandry. Understanding the behavior of Clostridium perfringens in its ecological niche, the poultry barn, is key to a sustainable and cost-effective production in the absence of AGPs. Using polymerase chain reaction and pulsed-field gel electrophoresis, we evaluated how the C. perfringens population evolved in drug-free commercial broiler chicken farms, either healthy or affected with recurring clinical necrotic enteritis outbreaks, over a 14-month period. We show that a high genotypic richness was associated with an increased risk of clinical necrotic enteritis. Also, necrotic enteritis-affected farms had a significant reduction of C. perfringens genotypic richness over time, an increase in the proportion of C. perfringens strains harboring the cpb2 gene, the netB gene, or both. Thus, necrotic enteritis occurrence is correlated with the presence of an initial highly diverse C. perfringens population, increasing the opportunity for the selective sweep of particularly virulent genotypes. Disease outbreaks also appear to largely influence the evolution of this bacterial species in poultry farms over time.

  13. Recurring Necrotic Enteritis Outbreaks in Commercial Broiler Chicken Flocks Strongly Influence Toxin Gene Carriage and Species Richness in the Resident Clostridium perfringens Population.

    Science.gov (United States)

    Gaucher, Marie-Lou; Perron, Gabriel G; Arsenault, Julie; Letellier, Ann; Boulianne, Martine; Quessy, Sylvain

    2017-01-01

    Extensive use of antibiotic growth promoters (AGPs) in food animals has been questioned due to the globally increasing problem of antibiotic resistance. For the poultry industry, digestive health management following AGP withdrawal in Europe has been a challenge, especially the control of necrotic enteritis. Much research work has focused on gut health in commercial broiler chicken husbandry. Understanding the behavior of Clostridium perfringens in its ecological niche, the poultry barn, is key to a sustainable and cost-effective production in the absence of AGPs. Using polymerase chain reaction and pulsed-field gel electrophoresis, we evaluated how the C. perfringens population evolved in drug-free commercial broiler chicken farms, either healthy or affected with recurring clinical necrotic enteritis outbreaks, over a 14-month period. We show that a high genotypic richness was associated with an increased risk of clinical necrotic enteritis. Also, necrotic enteritis-affected farms had a significant reduction of C. perfringens genotypic richness over time, an increase in the proportion of C. perfringens strains harboring the cpb2 gene, the netB gene, or both. Thus, necrotic enteritis occurrence is correlated with the presence of an initial highly diverse C. perfringens population, increasing the opportunity for the selective sweep of particularly virulent genotypes. Disease outbreaks also appear to largely influence the evolution of this bacterial species in poultry farms over time.

  14. Structure of Staphylococcal Enterotoxin E in Complex with TCR Defines the Role of TCR Loop Positioning in Superantigen Recognition.

    Directory of Open Access Journals (Sweden)

    Karin E J Rödström

    Full Text Available T cells are crucial players in cell-mediated immunity. The specificity of their receptor, the T cell receptor (TCR, is central for the immune system to distinguish foreign from host antigens. Superantigens are bacterial toxins capable of inducing a toxic immune response by cross-linking the TCR and the major histocompatibility complex (MHC class II and circumventing the antigen specificity. Here, we present the structure of staphylococcal enterotoxin E (SEE in complex with a human T cell receptor, as well as the unligated T cell receptor structure. There are clear structural changes in the TCR loops upon superantigen binding. In particular, the HV4 loop moves to circumvent steric clashes upon complex formation. In addition, a predicted ternary model of SEE in complex with both TCR and MHC class II displays intermolecular contacts between the TCR α-chain and the MHC, suggesting that the TCR α-chain is of importance for complex formation.

  15. Acid Sphingomyelinase Promotes Cellular Internalization of Clostridium perfringens Iota-Toxin.

    Science.gov (United States)

    Nagahama, Masahiro; Takehara, Masaya; Miyamoto, Kazuaki; Ishidoh, Kazumi; Kobayashi, Keiko

    2018-05-20

    Clostridium perfringens iota-toxin is a binary actin-ADP-ribosylating toxin composed of the enzymatic component Ia and receptor binding component Ib. Ib binds to a cell surface receptor, forms Ib oligomer in lipid rafts, and associates with Ia. The Ia-Ib complex then internalizes by endocytosis. Here, we showed that acid sphingomyelinase (ASMase) facilitates the cellular uptake of iota-toxin. Inhibitions of ASMase and lysosomal exocytosis by respective blockers depressed cell rounding induced by iota-toxin. The cytotoxicity of the toxin increased in the presence of Ca 2+ in extracellular fluids. Ib entered target cells in the presence but not the absence of Ca 2+ . Ib induced the extracellular release of ASMase in the presence of Ca 2+ . ASMase siRNA prevented the cell rounding induced by iota-toxin. Furthermore, treatment of the cells with Ib resulted in the production of ceramide in cytoplasmic vesicles. These observations showed that ASMase promotes the internalization of iota-toxin into target cells.

  16. Susceptibility of Clostridium perfringens strains from broiler chickens to antibiotics and anticoccidials.

    Science.gov (United States)

    Martel, A; Devriese, L A; Cauwerts, K; De Gussem, K; Decostere, A; Haesebrouck, F

    2004-02-01

    Clostridium perfringens strains isolated in 2002 from the intestines of broiler chickens from 31 different farms located in Belgium were tested for susceptibility to 12 antibiotics used for therapy, growth promotion or prevention of coccidiosis. All strains were uniformly sensitive to the ionophore antibiotics monensin, lasalocid, salinomycin, maduramycin and narasin. All were sensitive to avilamycin, tylosin and amoxicillin, while flavomycin (bambermycin) showed low or no activity. Chlortetracycline and oxytetracycline were active at very low concentrations, but low-level acquired resistance was detected in 66% of the strains investigated. Fifty percent of these strains carried the tetP(B) resistance gene, while the tet(Q) gene was detected in only one strain. One strain with high-level resistance against tetracyclines carried the tet(M) gene. Sixty-three percent of the strains showed low-level resistance to lincomycin. The lnu(A) and lnu(B) genes were each only found in one strain. Compared with a similar investigation carried out in 1980, an increase was seen in resistance percentages with lincomycin (63% against 49%) and a slight decrease with tetracycline (66% against 74%).

  17. Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves

    Directory of Open Access Journals (Sweden)

    Bonnie R. Valgaeren

    2015-07-01

    Full Text Available Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin.

  18. Spore membrane(s) as the site of damage within heated Clostridium perfringens spores.

    Science.gov (United States)

    Flowers, R S; Adams, D M

    1976-02-01

    Clostridium perfringens spores were injured by ultrahigh-temperature treatment at 105 C for 5 min. Injury was manifested as an increased sensitivity to polymyxin and neomycin. Since many of the survivors could not germinate normally the ultrahigh-temperature-treated spores were sensitized to and germinated by lysozyme. Polymyxin reportedly acts upon the cell membrane. Neomycin may inhibit protein synthesis and has surface-active properties. Injured spores were increasingly sensitive to known surface-active agents, sodium lauryl sulfate, sodium deoxycholate, and Roccal, a quaternary ammonium compound. Injured spores sensitive to polymyxin and neomycin also were osmotically fragile and died during outgrowth in a liquid medium unless the medium was supplemented with 20% sucrose, 10% dextran, or 10% polyvinylpyrrolidone. The results suggested that a spore structure destined to become cell membrane or cell wall was the site of injury. Repair of injury during outgrowth in the presence of protein, deoxyribonucleic acid, ribonucleic acid and cell wall synthesis inhibitors was consistent with this hypothesis.

  19. Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves

    Science.gov (United States)

    Valgaeren, Bonnie R.; Pardon, Bart; Goossens, Evy; Verherstraeten, Stefanie; Roelandt, Sophie; Timbermont, Leen; Van Der Vekens, Nicky; Stuyvaert, Sabrina; Gille, Linde; Van Driessche, Laura; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip; Deprez, Piet

    2015-01-01

    Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin. PMID:26184311

  20. Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves.

    Science.gov (United States)

    Valgaeren, Bonnie R; Pardon, Bart; Goossens, Evy; Verherstraeten, Stefanie; Roelandt, Sophie; Timbermont, Leen; Van Der Vekens, Nicky; Stuyvaert, Sabrina; Gille, Linde; Van Driessche, Laura; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip; Deprez, Piet

    2015-07-10

    Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin.

  1. Staphylococcus aureus and staphylococcal enterotoxin A in breaded chicken products: detection and behavior during the cooking process.

    Science.gov (United States)

    Pepe, Olimpia; Blaiotta, Giuseppe; Bucci, Francesca; Anastasio, Marilena; Aponte, Maria; Villani, Francesco

    2006-11-01

    In this study we examined the presence of Staphylococcus aureus and staphylococcal enterotoxin A (SEA) in 20 industrial breaded chicken products obtained from different retail butchers and supermarket stores in Italy. The levels of contamination in the products analyzed were quite low, although the pH values and water activities (a(w)) in the samples considered were in ranges favorable for S. aureus growth. As demonstrated by phenotypic and molecular characterization, in spite of the high percentage of coagulase-positive Staphylococcus strains, only three strains could be referred to the species S. aureus. Moreover, all the strains were negative in PCR assays targeting staphylococcal enterotoxin genes (seA to seE, seG to seJ, and seM to seO), as well as the toxic shock syndrome toxin 1 gene, and no SEA was detected in the retail breaded chicken samples analyzed by a reversed passive latex agglutination assay or by Western blotting. Hence, we evaluated the thermal resistance of two strains of SEA-producing S. aureus in a laboratory-scale preparation of precooked breaded chicken cutlets. The heat treatment employed in the manufacture determined the inactivation of S. aureus cells, but the preformed SEA remained active during product storage at 4 degrees C. The presence of the staphylococci and, in particular, of S. aureus in the retail breaded chicken products analyzed is a potential health risk for consumers since the pH and a(w) values of these kinds of products are favorable for S. aureus growth. The thermal process used during their manufacture can limit staphylococcal contamination but cannot eliminate preformed toxins.

  2. Comparative Genomics and Identification of an Enterotoxin-Bearing Pathogenicity Island, SEPI-1/SECI-1, in Staphylococcus epidermidis Pathogenic Strains.

    Science.gov (United States)

    Argemi, Xavier; Nanoukon, Chimène; Affolabi, Dissou; Keller, Daniel; Hansmann, Yves; Riegel, Philippe; Baba-Moussa, Lamine; Prévost, Gilles

    2018-02-25

    Staphylococcus epidermidis is a leading cause of nosocomial infections, majorly resistant to beta-lactam antibiotics, and may transfer several mobile genetic elements among the members of its own species, as well as to Staphylococcus aureus ; however, a genetic exchange from S. aureus to S. epidermidis remains controversial. We recently identified two pathogenic clinical strains of S. epidermidis that produce a staphylococcal enterotoxin C3-like (SEC) similar to that by S. aureus pathogenicity islands. This study aimed to determine the genetic environment of the SEC-coding sequence and to identify the mobile genetic elements. Whole-genome sequencing and annotation of the S. epidermidis strains were performed using Illumina technology and a bioinformatics pipeline for assembly, which provided evidence that the SEC-coding sequences were located in a composite pathogenicity island that was previously described in the S. epidermidis strain FRI909, called SePI-1/SeCI-1, with 83.8-89.7% nucleotide similarity. Various other plasmids were identified, particularly p_3_95 and p_4_95, which carry antibiotic resistance genes ( hsrA and dfrG , respectively), and share homologies with SAP085A and pUSA04-2-SUR11, two plasmids described in S. aureus . Eventually, one complete prophage was identified, ΦSE90, sharing 30 out of 52 coding sequences with the Acinetobacter phage vB_AbaM_IME200. Thus, the SePI-1/SeCI-1 pathogenicity island was identified in two pathogenic strains of S. epidermidis that produced a SEC enterotoxin causing septic shock. These findings suggest the existence of in vivo genetic exchange from S. aureus to S. epidermidis .

  3. Comparative Genomics and Identification of an Enterotoxin-Bearing Pathogenicity Island, SEPI-1/SECI-1, in Staphylococcus epidermidis Pathogenic Strains

    Directory of Open Access Journals (Sweden)

    Xavier Argemi

    2018-02-01

    Full Text Available Staphylococcus epidermidis is a leading cause of nosocomial infections, majorly resistant to beta-lactam antibiotics, and may transfer several mobile genetic elements among the members of its own species, as well as to Staphylococcus aureus; however, a genetic exchange from S. aureus to S. epidermidis remains controversial. We recently identified two pathogenic clinical strains of S. epidermidis that produce a staphylococcal enterotoxin C3-like (SEC similar to that by S. aureus pathogenicity islands. This study aimed to determine the genetic environment of the SEC-coding sequence and to identify the mobile genetic elements. Whole-genome sequencing and annotation of the S. epidermidis strains were performed using Illumina technology and a bioinformatics pipeline for assembly, which provided evidence that the SEC-coding sequences were located in a composite pathogenicity island that was previously described in the S. epidermidis strain FRI909, called SePI-1/SeCI-1, with 83.8–89.7% nucleotide similarity. Various other plasmids were identified, particularly p_3_95 and p_4_95, which carry antibiotic resistance genes (hsrA and dfrG, respectively, and share homologies with SAP085A and pUSA04-2-SUR11, two plasmids described in S. aureus. Eventually, one complete prophage was identified, ΦSE90, sharing 30 out of 52 coding sequences with the Acinetobacter phage vB_AbaM_IME200. Thus, the SePI-1/SeCI-1 pathogenicity island was identified in two pathogenic strains of S. epidermidis that produced a SEC enterotoxin causing septic shock. These findings suggest the existence of in vivo genetic exchange from S. aureus to S. epidermidis.

  4. Subinhibitory concentrations of thymol reduce enterotoxins A and B and alpha-hemolysin production in Staphylococcus aureus isolates.

    Directory of Open Access Journals (Sweden)

    Jiazhang Qiu

    Full Text Available BACKGROUND: Targeting bacterial virulence factors is now gaining interest as an alternative strategy to develop new types of anti-infective agents. It has been shown that thymol, when used at low concentrations, can inhibit the TSST-1 secretion in Staphylococcus aureus. However, there are no data on the effect of thymol on the production of other exotoxins (e.g., alpha-hemolysin and enterotoxins by S. aureus. METHODOLOGY/PRINCIPAL FINDINGS: Secretion of alpha-hemolysin, SEA and SEB in both methicillin-sensitive and methicillin-resistant S. aureus isolates cultured with graded subinhibitory concentrations of thymol was detected by immunoblot analysis. Hemolysin and tumor necrosis factor (TNF release assays were performed to elucidate the biological relevance of changes in alpha-hemolysin, SEA and SEB secretion induced by thymol. In addition, the influence of thymol on the transcription of hla, sea, and seb (the genes encoding alpha-hemolysin, SEA and SEB, respectively was analyzed by quantitative RT-PCR. Thymol inhibited transcription of hla, sea and seb in S. aureus, resulting in a reduction of alpha-hemolysin, SEA and SEB secretion and, thus, a reduction in hemolytic and TNF-inducing activities. CONCLUSIONS/SIGNIFICANCE: Subinhibitory concentrations of thymol decreased the production of alpha-hemolysin, SEA and SEB in both MSSA and MRSA in a dose-dependent manner. These data suggest that thymol may be useful for the treatment of S. aureus infections when used in combination with beta-lactams and glycopeptide antibiotics, which induce expression of alpha-hemolysin and enterotoxins at subinhibitory concentrations. Furthermore, the structure of thymol may potentially be used as a basic structure for development of drugs aimed against these bacterial virulence factors.

  5. Effects of Bacillus coagulans supplementation on the growth performance and gut health of broiler chickens with Clostridium perfringens-induced necrotic enteritis.

    Science.gov (United States)

    Wu, Yuanyuan; Shao, Yujing; Song, Bochen; Zhen, Wenrui; Wang, Zhong; Guo, Yuming; Shahid, Muhammad Suhaib; Nie, Wei

    2018-01-01

    The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis (NE) due to Clostridium perfringens . This study was conducted to investigate the effects of feeding Bacillus coagulans on the growth performance and gut health of broiler chickens with C. perfringens -induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels (0 or 4 × 10 9  CFU/kg of diet) and two disease challenge statuses (control or NE challenged). NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C. perfringens growth and liver invasion, and enhanced anti- C. perfringens specific sIgA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly ( P  coagulans showed a significant ( P  coagulans improved intestinal barrier structure, further increased specific sIgA levels and alkaline phosphatase (IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mRNA, and inhibited the growth, colonization, and invasion of C. perfringens ; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mRNA levels. These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens -induced NE in broiler chickens.

  6. Metabolic dependent and independent pH-drop shuts down VirSR quorum sensing in Clostridium perfringens.

    Science.gov (United States)

    Adachi, Keika; Ohtani, Kaori; Kawano, Michio; Singh, Ravindra Pal; Yousuf, Basit; Sonomoto, Kenji; Shimizu, Tohru; Nakayama, Jiro

    2018-05-01

    Clostridium perfringens produces various exotoxins and enzymes that cause food poisoning and gas gangrene. The genes involved in virulence are regulated by the agr-like quorum sensing (QS) system, which consists of a QS signal synthesis system and a VirSR two-component regulatory system (VirSR TCS) which is a global regulatory system composed of signal sensor kinase (VirS) and response regulator (VirR). We found that the perfringolysin O gene (pfoA) was transiently expressed during mid-log phase of bacterial growth; its expression was rapidly shut down thereafter, suggesting the existence of a self-quorum quenching (sQQ) system. The sQQ system was induced by the addition of stationary phase culture supernatant (SPCS). Activity of the sQQ system was heat stable, and was present following filtration through the ultrafiltration membrane, suggesting that small molecules acted as sQQ agents. In addition, sQQ was also induced by pure acetic and butyric acids at concentrations equivalent to those in the stationary phase culture, suggesting that organic acids produced by C. perfringens were involved in sQQ. In pH-controlled batch culture, sQQ was greatly diminished; expression level of pfoA extended to late-log growth phase, and was eventually increased by one order of magnitude. Furthermore, hydrochloric acid induced sQQ at the same pH as was used in organic acids. SPCS also suppressed the expression of genes regulated by VirSR TCS. Overall, the expression of virulence factors of C. perfringens was downregulated by the sQQ system, which was mediated by primary acidic metabolites and acidic environments. This suggested the possibility of pH-controlled anti-virulence strategies. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. The safe enterocin DD14 is a leaderless two-peptide bacteriocin with anti-Clostridium perfringens activity.

    Science.gov (United States)

    Caly, Delphine L; Chevalier, Mickaël; Flahaut, Christophe; Cudennec, Benoit; Al Atya, Ahmed Khassaf; Chataigné, Gabrielle; D'Inca, Romain; Auclair, Eric; Drider, Djamel

    2017-03-01

    Enterococcus faecalis 14, a strain previously isolated from meconium, displayed activity against four Clostridium perfringens isolates when co-cultured on agar plates. The anti-Clostridium activity was ascribed to the production of enterocin DD14, which was subsequently purified. The minimum inhibitory concentration (MIC) of enterocin DD14 against one collection strain and one clinical C. perfringens strain was determined at 50 µg/mL. Furthermore, using the intestinal epithelial cell line IPEC-1, it was shown that E. faecalis 14 was not cytotoxic after 24 h of contact, and no cytotoxicity was observed when IPEC-1 cells were incubated with pure enterocin DD14 for 4 h. Enterocin DD14 was characterised using mass spectrometry and was shown to consist of two small proteins of 5200.74 Da and 5206.41 Da, respectively. The two peptides (DD14A and DD14B) have highly similar amino acid sequences and no signal peptide, which classifies enterocin DD14 as a class IIb leaderless two-peptide bacteriocin. The genes encoding DD14A and DD14B were sequenced and were shown to be 100% identical to other previously described enterocins MR10A and MR10B, in contrast to the producing strains, which are different. Consequently, the present in vitro study supports the potential of this E. faecalis 14 strain and/or its purified enterocin DD14 as putative anti-C. perfringens compounds in chickens. Copyright © 2017. Published by Elsevier B.V.

  8. Molecular characterization of podoviral bacteriophages virulent for Clostridium perfringens and their comparison with members of the Picovirinae.

    Directory of Open Access Journals (Sweden)

    Nikolay V Volozhantsev

    Full Text Available Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium responsible for human food-borne disease as well as non-food-borne human, animal and poultry diseases. Because bacteriophages or their gene products could be applied to control bacterial diseases in a species-specific manner, they are potential important alternatives to antibiotics. Consequently, poultry intestinal material, soil, sewage and poultry processing drainage water were screened for virulent bacteriophages that lysed C. perfringens. Two bacteriophages, designated ΦCPV4 and ΦZP2, were isolated in the Moscow Region of the Russian Federation while another closely related virus, named ΦCP7R, was isolated in the southeastern USA. The viruses were identified as members of the order Caudovirales in the family Podoviridae with short, non-contractile tails of the C1 morphotype. The genomes of the three bacteriophages were 17.972, 18.078 and 18.397 kbp respectively; encoding twenty-six to twenty-eight ORF's with inverted terminal repeats and an average GC content of 34.6%. Structural proteins identified by mass spectrometry in the purified ΦCP7R virion included a pre-neck/appendage with putative lyase activity, major head, tail, connector/upper collar, lower collar and a structural protein with putative lysozyme-peptidase activity. All three podoviral bacteriophage genomes encoded a predicted N-acetylmuramoyl-L-alanine amidase and a putative stage V sporulation protein. Each putative amidase contained a predicted bacterial SH3 domain at the C-terminal end of the protein, presumably involved with binding the C. perfringens cell wall. The predicted DNA polymerase type B protein sequences were closely related to other members of the Podoviridae including Bacillus phage Φ29. Whole-genome comparisons supported this relationship, but also indicated that the Russian and USA viruses may be unique members of the sub-family Picovirinae.

  9. Sialidases affect the host cell adherence and epsilon toxin-induced cytotoxicity of Clostridium perfringens type D strain CN3718.

    Directory of Open Access Journals (Sweden)

    Jihong Li

    2011-12-01

    Full Text Available Clostridium perfringens type B or D isolates, which cause enterotoxemias or enteritis in livestock, produce epsilon toxin (ETX. ETX is exceptionally potent, earning it a listing as a CDC class B select toxin. Most C. perfringens strains also express up to three different sialidases, although the possible contributions of those enzymes to type B or D pathogenesis remain unclear. Type D isolate CN3718 was found to carry two genes (nanI and nanJ encoding secreted sialidases and one gene (nanH encoding a cytoplasmic sialidase. Construction in CN3718 of single nanI, nanJ and nanH null mutants, as well as a nanI/nanJ double null mutant and a triple sialidase null mutant, identified NanI as the major secreted sialidase of this strain. Pretreating MDCK cells with NanI sialidase, or with culture supernatants of BMC206 (an isogenic CN3718 etx null mutant that still produces sialidases enhanced the subsequent binding and cytotoxic effects of purified ETX. Complementation of BMC207 (an etx/nanH/nanI/nanJ null mutant showed this effect is mainly attributable to NanI production. Contact between BMC206 and certain mammalian cells (e.g., enterocyte-like Caco-2 cells resulted in more rapid sialidase production and this effect involved increased transcription of BMC206 nanI gene. BMC206 was shown to adhere to some (e.g. Caco-2 cells, but not all mammalian cells, and this effect was dependent upon sialidase, particularly NanI, expression. Finally, the sialidase activity of NanI (but not NanJ or NanH could be enhanced by trypsin. Collectively these in vitro findings suggest that, during type D disease originating in the intestines, trypsin may activate NanI, which (in turn could contribute to intestinal colonization by C. perfringens type D isolates and also increase ETX action.

  10. Coupling immunomagnetic separation on magnetic beads with matrix-assisted laser desorption ionization-time of flight mass spectrometry for detection of Staphylococcal Enterotoxin B

    Czech Academy of Sciences Publication Activity Database

    Schlosser, G.; Kačer, P.; Kuzma, Marek; Szilágyi, Z.; Sorrentino, Z.; Manzo, C.; Pizzano, R.; Malorni, L.; Poscfalvi, G.

    2007-01-01

    Roč. 73, č. 21 (2007), s. 6945-6952 ISSN 0099-2240 Grant - others:IT(IT) project SIFORTI (MIUR-CNR, Legge 449/97); XE(XE) 94.05.09.103, ARINCO 94.IT.16.028 Institutional research plan: CEZ:AV0Z50200510 Keywords : mass spectrometry * staphylococcal enterotoxin b * bacterial protein toxins Subject RIV: EE - Microbiology, Virology Impact factor: 4.004, year: 2007

  11. Prevalence of enterotoxin-encoding genes and antimicrobial resistance in coagulase-negative and coagulase-positive Staphylococcus isolates from black pudding

    Directory of Open Access Journals (Sweden)

    Tiane Martin de Moura

    2012-10-01

    Full Text Available INTRODUCTION: Staphylococcal species are pathogens that are responsible for outbreaks of foodborne diseases. The aim of this study was to investigate the prevalence of enterotoxin-genes and the antimicrobial resistance profile in staphylococcus coagulase-negative (CoNS and coagulasepositive (CoPS isolates from black pudding in southern Brazil. METHODS: Two hundred typical and atypical colonies from Baird-Parker agar were inoculated on mannitol salt agar. Eighty-two mannitol-positive staphylococci were submitted to conventional biochemical tests and antimicrobial susceptibility profiling. The presence of coagulase (coa and enterotoxin (se genes was investigated by polymerase chain reaction. RESULTS: The isolates were divided into 2 groups: 75.6% (62/82 were CoNS and 24.4% (20/82 were CoPS. The biochemical tests identified 9 species, of which Staphylococcus saprophyticus (37.8% and Staphylococcus carnosus (15.9% were the most prevalent. Antimicrobial susceptibility tests showed resistance phenotypes to antibiotics widely administered in humans, such as gentamicin, tetracycline, chloramphenicol, and erythromycin. The coa gene was detected in 19.5% (16/82 of the strains and 4 polymorphic DNA fragments were observed. Five CoNS isolates carrying the coa gene were submitted for 16S rRNA sequencing and 3 showed similarity with CoNS. Forty strains were positive for at least 1 enterotoxin-encoding gene, the genes most frequently detected were sea (28.6% and seb (27.5%. CONCLUSIONS: The presence of antimicrobial resistant and enterotoxin-encoding genes in staphylococci isolates from black pudding indicated that this fermented food may represent a potential health risk, since staphylococci present in food could cause foodborne diseases or be a possible route for the transfer of antimicrobial resistance to humans.

  12. Influence of holding temperature on the growth and survival of Salmonella spp. and Staphylococcus aureus and the production of staphylococcal enterotoxin in egg products.

    Science.gov (United States)

    Yang, S E; Yu, R C; Chou, C C

    2001-01-22

    In this study, growth and survival of Salmonella spp. and Staphylococcus aureus in steamed egg and scrambled egg held at 5, 18, 22, 37, 55 and 60 degrees C are investigated. The production of staphylococcal enterotoxin in steamed egg is also examined. Results reveal that Salmonella spp. and Staph. aureus in the egg products multiply best at 37 degrees C, followed closely by 22 and 18 degrees C. Neither pathogen showed growth in the egg products held at 5 degrees C. Initial inoculation dose, holding temperature and holding time affected the population of both organisms found in the egg products. Staphylococcal enterotoxin A (SEA) and B (SEB) are detected only in the egg products held at 37 or 22 degrees C. After holding at 37 degrees C for 36 h, scrambled egg inoculated with ca. 5.0 log cfu/g Staph. aureus contains the highest levels of SEA (> 64 ng/g) and SEB (> 64 ng/g). Although Salmonella spp. and Staph. aureus grow better in steamed eggs than in scrambled eggs, production of staphylococcal enterotoxin, in general, was higher in scrambled eggs than in steamed eggs. On the other hand, a repaid destruction of the test organisms in steamed eggs held at 60 degrees C was observed. Holding the steamed eggs at 60 degrees C, Salmonella spp. and Staph. aureus with an initial population of ca. 5.9 and 5.6 log cfu/g, respectively, reduced to a non-detectable level in 1 h.

  13. Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar.

    Science.gov (United States)

    Aung, Meiji Soe; San, Thida; Aye, Mya Mya; Mya, San; Maw, Win Win; Zan, Khin Nyein; Htut, Wut Hmone Win; Kawaguchiya, Mitsuyo; Urushibara, Noriko; Kobayashi, Nobumichi

    2017-08-04

    Asymptomatic carriers of toxigenic Staphylococcus aureus are potential source of diseases, including food poisoning. Toxigenic potential and genetic traits of colonizing S. aureus were investigated for 563 healthy food handlers in Myanmar. Carriage of S. aureus was found in 110 individuals (19.5%), and a total of 144 S. aureus isolates were recovered from nasal cavities (110 isolates) and hands (34 isolates). Panton-Valentine leucocidin genes ( pvl ) were detected in 18 isolates (12.5%), among which 11 isolates were classified into coa -VIa, agr type III, and ST1930 (CC96) that had been also detected in pvl -positive clinical isolates in Myanmar. A pvl -positive, ST2250 nasal isolate was identified as S. argenteus , a novel coagulase-positive staphylococcus species. Toxic shock syndrome toxin-1 (TSST-1) gene was detected in five pvl -negative isolates. All of the 144 isolates harbored at least one of the 21 enterotoxin(-like) gene(s). The most prevalent enterotoxin(-like) gene was selw (98%), followed by selx (97%), sei (28%), sely (28%), sem (26%), sel (24%), and sea and sec (22% each). Considerable genetic diversity with five groups was detected for selw . The present study revealed the relatively high rate of pvl , as well as the wide distribution of enterotoxin(-like) genes among colonizing S. aureus in Myanmar.

  14. Use of natural ingredients to control growth of Clostridium perfringens in naturally cured frankfurters and hams.

    Science.gov (United States)

    Jackson, Armitra L; Kulchaiyawat, Charlwit; Sullivan, Gary A; Sebranek, Joseph G; Dickson, James S

    2011-03-01

    A major concern for processed meats marketed as natural/organic is that they do not contain nitrite in concentrations known to be most effective for inhibiting foodborne pathogens. Supplemental treatments to increase the level and consistency of antimicrobial protection in these products may be important to provide consumers with the degree of safety that they have come to expect from conventionally cured meats. Therefore, the objective of this study was to identify and test ingredients that might improve processed meat product safety without altering their natural/organic status. Eight treatments of hams and frankfurters were prepared: (A) uncured control (typical ingredients except nitrite and nitrate); (B) conventionally cured control (erythorbate, nitrite, and a lactate-diacetate blend); (C) natural nitrate cure (including starter culture containing Staphylococcus carnosus); (D) natural nitrate cure (culture and natural antimicrobial A containing a vinegar, lemon, and cherry powder blend); (E) natural nitrate cure (culture and antimicrobial B containing a cultured sugar and vinegar blend); (F) natural nitrite cure without additional antimicrobials; (G) natural nitrite cure with natural antimicrobial A; and (H) natural nitrite cure with antimicrobial B. For the hams, treatments C, D, E, and H impacted growth of Clostridium perfringens to the same extent (P cured control (approximately 2 log less growth over time than uncured control). For frankfurters, treatments D, G, and H had an effect (approximately 1 log) on growth equivalent to that of the conventionally cured control (P cured meats have more potential for pathogen growth than conventionally cured products, but supplemental natural ingredients offer safety improvement.

  15. Quantitative Detection of Clostridium perfringens in Broiler Chickens by Real-Time PCR Targeting the Alpha-Toxin Gene

    DEFF Research Database (Denmark)

    Abildgaard, Lone; Engberg, Ricarda M.; Schramm, Andreas

    2006-01-01

    was developed by sequencing the α-toxin gene from ~60 strains of C. perfringens, isolated from diseased as well as healthy broilers. For its application to the chicken gastrointestinal tract (i.e., ileum), DNA extraction efficiency and potential inhibition of the real-time PCR process by ileum content...

  16. Effects of Eimeria maxima and Clostridium perfringens infections on Cecal Microbiome in Broiler Chickens Analyzed by 16S rRNA Sequencing

    Science.gov (United States)

    Background: Necrotic enteritis (NE) and coccidiosis are considered two of the priority enteric diseases impacting poultry production in the U.S. and Europe, and are responsible for the annual economic loss of US $6 billion and $ 3 billion, respectively. NE is caused by Clostridium perfringens (CP), ...

  17. Adsorptive effects of di-tri-octahedral smectite on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies.

    Science.gov (United States)

    Lawler, Jacquelin Boggs; Hassel, Diana M; Magnuson, Roberta J; Hill, Ashley E; McCue, Patrick M; Traub-Dargatz, Josie L

    2008-02-01

    To determine the adsorptive capability of di-tri-octahedral smectite (DTOS) on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies. 3 C perfringens exotoxins and 9 colostral samples. Alpha, beta, and beta-2 exotoxins were individually co-incubated with serial dilutions of DTOS or bismuth subsalicylate, and the amount of toxin remaining after incubation was determined via toxin-specific ELISAs. Colostral samples from healthy mares were individually co-incubated with serial dilutions of DTOS, and colostral IgG concentrations were determined via single radial immunodiffusion assay. Di-tri-octahedral smectite decreased the amount of each C perfringens exotoxin in co-incubated samples in a dose-dependent manner and was more effective than bismuth subsalicylate at reducing exotoxins in vitro. Decreases in the concentration of IgG were detected in samples of colostrum that were combined with DTOS at 1:4 through 1:16 dilutions, whereas no significant decrease was evident with DTOS at the 1:32 dilution. Di-tri-octahedral smectite effectively adsorbed C perfringens exotoxins in vitro and had a dose-dependent effect on the availability of equine colostral antibodies. Results suggested that DTOS may be an appropriate adjunctive treatment in the management of neonatal clostridiosis in horses. In vivo studies are necessary to fully assess the clinical efficacy of DTOS treatment.

  18. Multiplex PCR assay for the simultaneous detection of C. perfringens, P. aeruginosa and K. pneumoniae

    Directory of Open Access Journals (Sweden)

    Pradeepkiran Jangampalli Adi

    2015-11-01

    Results and conclusions: Through this approach, the above pathogens were detected simultaneously with high specificity in pure cultures and from the blood and urine samples. The results were correlated with normal diagnostic process, and proved to be more sensitive and specific diagnostic technique in the simultaneous detection of C. perfringens, P. aeruginosa and K. pneumoniae.

  19. Vaccination with Clostridium perfringens recombinant proteins in combination with Montanide™ ISA 71 VG adjuvant increases protection against experimental necrotic enteritis in commercial broiler chickens

    Science.gov (United States)

    This study was performed to compare four Clostridium perfringens recombinant proteins as vaccine candidates using the Montanide™ ISA 71 VG adjuvant in an experimental model of necrotic enteritis. Broiler chickens were immunized with clostridial recombinant proteins with ISA 71 VG, and intestinal le...

  20. Draft genome sequences of clostridium perfringens strain LLY_N11, a pathogenic isolate of necrotic enteritis from a healthy chicken

    Science.gov (United States)

    Clostridium perfringens strain LLY_N11 is a commensal bacterial isolate from a healthy chicken that produced a necrotic enteritis in experimental studies. Here we present the assembly and annotation of its genome, which may provide further insights into improved understanding of the molecular mechan...

  1. A Thermophilic Phage Endolysin Fusion to a Clostridium perfringens-Specific Cell Wall Binding Domain Creates an Anti-Clostridium Antimicrobial with Improved Thermostability

    Directory of Open Access Journals (Sweden)

    Steven M. Swift

    2015-06-01

    Full Text Available Clostridium perfringens is the third leading cause of human foodborne bacterial disease and is the presumptive etiologic agent of necrotic enteritis among chickens. Treatment of poultry with antibiotics is becoming less acceptable. Endolysin enzymes are potential replacements for antibiotics. Many enzymes are added to animal feed during production and are subjected to high-heat stress during feed processing. To produce a thermostabile endolysin for treating poultry, an E. coli codon-optimized gene was synthesized that fused the N-acetylmuramoyl-L-alanine amidase domain from the endolysin of the thermophilic bacteriophage ɸGVE2 to the cell-wall binding domain (CWB from the endolysin of the C. perfringens-specific bacteriophage ɸCP26F. The resulting protein, PlyGVE2CpCWB, lysed C. perfringens in liquid and solid cultures. PlyGVE2CpCWB was most active at pH 8, had peak activity at 10 mM NaCl, 40% activity at 150 mM NaCl and was still 16% active at 600 mM NaCl. The protein was able to withstand temperatures up to 50° C and still lyse C. perfringens. Herein, we report the construction and characterization of a thermostable chimeric endolysin that could potentially be utilized as a feed additive to control the bacterium during poultry production.

  2. Ultrasensitive Electrochemical Detection of Clostridium perfringens DNA Based Morphology-Dependent DNA Adsorption Properties of CeO2 Nanorods in Dairy Products

    Directory of Open Access Journals (Sweden)

    Xingcan Qian

    2018-06-01

    Full Text Available Foodborne pathogens such as Clostridium perfringens can cause diverse illnesses and seriously threaten to human health, yet far less attention has been given to detecting these pathogenic bacteria. Herein, two morphologies of nanoceria were synthesized via adjusting the concentration of NaOH, and CeO2 nanorod has been utilized as sensing material to achieve sensitive and selective detection of C. perfringens DNA sequence due to its strong adsorption ability towards DNA compared to nanoparticle. The DNA probe was tightly immobilized on CeO2/chitosan modified electrode surface via metal coordination, and the DNA surface density was 2.51 × 10−10 mol/cm2. Under optimal experimental conditions, the electrochemical impedance biosensor displays favorable selectivity toward target DNA in comparison with base-mismatched and non-complementary DNA. The dynamic linear range of the proposed biosensor for detecting oligonucleotide sequence of Clostridium perfringens was from 1.0 × 10−14 to 1.0 × 10−7 mol/L. The detection limit was 7.06 × 10−15 mol/L. In comparison, differential pulse voltammetry (DPV method quantified the target DNA with a detection limit of 1.95 × 10−15 mol/L. Moreover, the DNA biosensor could detect C. perfringens extracted DNA in dairy products and provided a potential application in food quality control.

  3. Riverbed sediments in the Apies River, South Africa: recommending the use of both Clostridium perfringens and Escherichia coli as indicators of faecal pollution

    CSIR Research Space (South Africa)

    Abia, ALK

    2015-12-01

    Full Text Available . Real-time polymerase chain reaction (RT-PCR) was used to confirm isolates. E. coli and C. perfringens were enumerated in sediment by firstly using the water displacement approach to dislodge organisms from sediment and then subsequently followed...

  4. Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

    Directory of Open Access Journals (Sweden)

    Miseon Park

    2014-01-01

    Full Text Available Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.

  5. Comparison of the Effect of Curing Ingredients Derived from Purified and Natural Sources on Inhibition of Clostridium perfringens Outgrowth during Cooling of Deli-Style Turkey Breast.

    Science.gov (United States)

    King, Amanda M; Glass, Kathleen A; Milkowski, Andrew L; Sindelar, Jeffrey J

    2015-08-01

    The antimicrobial impact of purified and natural sources of both nitrite and ascorbate were evaluated against Clostridium perfringens during the postthermal processing cooling period of deli-style turkey breast. The objective of phase I was to assess comparable concentrations of nitrite (0 or 100 ppm) and ascorbate (0 or 547 ppm) from both purified and natural sources. Phase II was conducted to investigate concentrations of nitrite (50, 75, or 100 ppm) from cultured celery juice powder and ascorbate (0, 250, or 500 ppm) from cherry powder to simulate alternative curing formulations. Ground turkey breast (75% moisture, 1.2% salt, pH 6.2) treatments were inoculated with C. perfringens spores (three-strain mixture) to yield 2.5 log CFU/g. Individual 50-g portions were vacuum packaged, cooked to 71.1°C, and chilled from 54.4 to 26.7°C in 5 h and from 26.7 to 7.2°C in 10 additional hours. Triplicate samples were assayed for growth of C. perfringens at predetermined intervals by plating on tryptose-sulfite-cycloserine agar; experiments were replicated three times. In phase I, uncured, purified nitrite, and natural nitrite treatments without ascorbate had 5.3-, 4.2-, and 4.4-log increases in C. perfringens, respectively, at 15 h, but nitrite and 547 ppm of ascorbate from either source. In phase II, 0, 50, 75, and 100 ppm of nitrite and 50 ppm of nitrite plus 250 ppm of ascorbate supported 4.5-, 3.9-, 3.5-, 2.2-, and 1.5-log increases in C. perfringens, respectively. In contrast, nitrite and 500 ppm of ascorbate or ≥75 ppm of nitrite and ≥250 ppm of ascorbate. These results confirm that equivalent concentrations of nitrite, regardless of the source, provide similar inhibition of C. perfringens during chilling and that ascorbate enhances the antimicrobial effect of nitrite on C. perfringens at concentrations commonly used in alternative cured meats.

  6. An alternative explanation for the occurrence of short circuit current increases in the small intestine following challenge by bacterial enterotoxins.

    Science.gov (United States)

    Lucas, M L

    2013-10-01

    Secretory diarrhoeal disease due to enterotoxins is thought to arise from the enhancement to pathologically high rates of normally occurring chloride ion and therefore fluid secretion from enterocytes. In support of this concept, many enterotoxins increase intestinal short-circuit current, regarded now as faithfully reflecting the increased chloride ion secretion. Contradicting this assumption, STa reduces absorption but does not cause secretion in vivo although short-circuit current is increased in vitro. There is therefore a mismatch between an assumed enterocyte mediated secretory event that should but does not cause net fluid secretion and an undoubtedly increased short-circuit current. It is proposed here that short-circuit current increases are not themselves secretory events but result from interrupted fluid absorption. A noteworthy feature of compounds that inhibit the increase in short-circuit current is that the majority are vasoactive, neuroactive or both. In general, vasodilator substances increase current. An alternative hypothesis for the origin of short-circuit current increases is that these result from reflex induction of electrogenic fluid absorption. This reflex enhances a compensatory response that is also present at a cellular level. An intestinal reflex is therefore proposed by which decreases in interstitial and intravascular volume or pressure within the intestine initiate an electrogenic fluid absorption mechanism that compensates for the loss of electrically neutral fluid absorption. This hypothesis would explain the apparently complex pharmacology of short-circuit current increases since many depressor substances have receptors in common with enterocytes and enteric nerves. The proposed alternative view of the origin of short-circuit current increases assumes that these do not represent chloride secretion from the enterocytes. This view may therefore aid the successful development of anti-diarrhoeal drugs to overcome a major cause of

  7. M cell-targeting strategy facilitates mucosal immune response and enhances protection against CVB3-induced viral myocarditis elicited by chitosan-DNA vaccine.

    Science.gov (United States)

    Ye, Ting; Yue, Yan; Fan, Xiangmei; Dong, Chunsheng; Xu, Wei; Xiong, Sidong

    2014-07-31

    Efficient delivery of antigen to mucosal associated lymphoid tissue is a first and critical step for successful induction of mucosal immunity by vaccines. Considering its potential transcytotic capability, M cell has become a more and more attractive target for mucosal vaccines. In this research, we designed an M cell-targeting strategy by which mucosal delivery system chitosan (CS) was endowed with M cell-targeting ability via conjugating with a CPE30 peptide, C terminal 30 amino acids of clostridium perfringens enterotoxin (CPE), and then evaluated its immune-enhancing ability in the context of coxsackievirus B3 (CVB3)-specific mucosal vaccine consisting of CS and a plasmid encoding CVB3 predominant antigen VP1. It had shown that similar to CS-pVP1, M cell-targeting CPE30-CS-pVP1 vaccine appeared a uniform spherical shape with about 300 nm diameter and +22 mV zeta potential, and could efficiently protect DNA from DNase I digestion. Mice were orally immunized with 4 doses of CPE30-CS-pVP1 containing 50 μg pVP1 at 2-week intervals and challenged with CVB3 4 weeks after the last immunization. Compared with CS-pVP1 vaccine, CPE30-CS-pVP1 vaccine had no obvious impact on CVB3-specific serum IgG level and splenic T cell immune responses, but significantly increased specific fecal SIgA level and augmented mucosal T cell immune responses. Consequently, much milder myocarditis and lower viral load were witnessed in CPE30-CS-pVP1 immunized group. The enhanced immunogenicity and immunoprotection were associated with the M cell-targeting ability of CPE30-CS-pVP1 which improved its mucosal uptake and transcytosis. Our findings indicated that CPE30-CS-pVP1 may represent a novel prophylactic vaccine against CVB3-induced myocarditis, and this M cell-targeting strategy indeed could be applied as a promising and universal platform for mucosal vaccine development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effect of meat ingredients (sodium nitrite and erythorbate) and processing (vacuum storage and packaging atmosphere) on germination and outgrowth of Clostridium perfringens spores in ham during abusive cooling.

    Science.gov (United States)

    Redondo-Solano, Mauricio; Valenzuela-Martinez, Carol; Cassada, David A; Snow, Daniel D; Juneja, Vijay K; Burson, Dennis E; Thippareddi, Harshavardhan

    2013-09-01

    The effect of nitrite and erythorbate on Clostridium perfringens spore germination and outgrowth in ham during abusive cooling (15 h) was evaluated. Ham was formulated with ground pork, NaNO2 (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 547 ppm). Ten grams of meat (stored at 5 °C for 3 or 24 h after preparation) were transferred to a vacuum bag and inoculated with a three-strain C. perfringens spore cocktail to obtain an inoculum of ca. 2.5 log spores/g. The bags were vacuum-sealed, and the meat was heat treated (75 °C, 20 min) and cooled within 15 h from 54.4 to 7.2 °C. Residual nitrite was determined before and after heat treatment using ion chromatography with colorimetric detection. Cooling of ham (control) stored for 3 and 24 h, resulted in C. perfringens population increases of 1.46 and 4.20 log CFU/g, respectively. For samples that contained low NaNO2 concentrations and were stored for 3 h, C. perfringens populations of 5.22 and 2.83 log CFU/g were observed with or without sodium erythorbate, respectively. Residual nitrite was stable (p > 0.05) for both storage times. Meat processing ingredients (sodium nitrite and sodium erythorbate) and their concentrations, and storage time subsequent to preparation of meat (oxygen content) affect C. perfringens spore germination and outgrowth during abusive cooling of ham. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Clostridium perfringens em rações e águas fornecidos a frangos de corte em granjas avícolas do interior paulista: Brasil Clostridium perfringens search in water and ration used in the raising of broiler in sheds of São Paulo State: Brazil

    Directory of Open Access Journals (Sweden)

    Rubén Pablo Schocken-Iturrino

    2010-02-01

    Full Text Available Através de métodos bacteriológicos convencionais, avaliou-se a contaminação por Clostridium perfringens na ração e água utilizadas na alimentação e dessedentação de frangos de corte em diferentes regiões avícolas do interior paulista. C. perfringens esteve presente em 42 e 30% das amostras de ração e águas analisadas, respectivamente. As médias das contagens foram 6,7 x 10-2UFC mL para as amostras de água e 3,69 x 10-2UFC g para as de rações. As altas freqüências e contagens de C. perfringens verificadas nas rações e nas águas podem estar associadas à falta de higiene geral na manipulação e armazenamento dos mesmos. Sugere-se o monitoramento periódico da presença de C. perfringens nestas fontes, com a finalidade de evitar tal patógeno, em vista que o mesmo pode causar um surto de enterite necrótica levando, assim a grandes prejuízos na produção avícola.Through conventional bacteriological methods, the contamination by Clostridium perfringens was evaluated in the ration and water used in the feeding of poultry chickens from different region of the interior from São Paulo. C. perfringens was present in 42 and 30% of the ration samples and waters analyzed respectively. The averages of the countings were 6.7 x 10-2CFU mL for the samples of water and 3.69 x 10-2CFU g for rations. The high frequencies and countings of C. perfringens verified in the rations and in the waters may be associated to the lack of general hygiene in the manipulation and storage of the same ones. These suggests a periodic monitoration of the presence of C. perfringens in these sources, with the purpose of avoiding such pathogen, in view that this organism can provoke an outbreak of necrotic enteritis, and cause great damages in the poultry production.

  10. Attenuation of massive cytokine response to the staphylococcal enterotoxin B superantigen by the innate immunomodulatory protein lactoferrin

    Science.gov (United States)

    Hayworth, J L; Kasper, K J; Leon-Ponte, M; Herfst, C A; Yue, D; Brintnell, W C; Mazzuca, D M; Heinrichs, D E; Cairns, E; Madrenas, J; Hoskin, D W; McCormick, J K; Haeryfar, S M M

    2009-01-01

    Staphylococcal enterotoxin B (SEB) is a pyrogenic exotoxin and a potent superantigen which causes massive T cell activation and cytokine secretion, leading to profound immunosuppression and morbidity. The inhibition of SEB-induced responses is thus considered a goal in the management of certain types of staphylococcal infections. Lactoferrin (LF) is a multi-functional glycoprotein with both bacteriostatic and bactericidal activities. In addition, LF is known to have potent immunomodulatory properties. Given the anti-microbial and anti-inflammatory properties of this protein, we hypothesized that LF can modulate T cell responses to SEB. Here, we report that bovine LF (bLF) was indeed able to attenuate SEB-induced proliferation, interleukin-2 production and CD25 expression by human leucocyte antigen (HLA)-DR4 transgenic mouse T cells. This inhibition was not due to bLF's iron-binding capacity, and could be mimicked by the bLF-derived peptide lactoferricin. Cytokine secretion by an engineered SEB-responsive human Jurkat T cell line and by peripheral blood mononuclear cells from healthy donors was also inhibited by bLF. These findings reveal a previously unrecognized property of LF in modulation of SEB-triggered immune activation and suggest a therapeutic potential for this naturally occurring protein during toxic shock syndrome. PMID:19659771

  11. Ultrasensitive electrochemical immunoassay of staphylococcal enterotoxin B in food using enzyme-nanosilica-doped carbon nanotubes for signal amplification.

    Science.gov (United States)

    Tang, Dianping; Tang, Juan; Su, Biling; Chen, Guonan

    2010-10-27

    A new sandwich-type electrochemical immunoassay for ultrasensitive detection of staphylococcal enterotoxin B (SEB) in food was developed using horseradish peroxidase-nanosilica-doped multiwalled carbon nanotubes (HRPSiCNTs) for signal amplification. Rabbit polyclonal anti-SEB antibodies immobilized on the screen-printed carbon electrode (SPCE) and covalently bound to the HRPSiCNTs were used as capture antibodies and detection antibodies, respectively. In the presence of SEB analyte, the sandwich-type immunocomplex could be formed between the immobilized anti-SEB on the SPCE and anti-SEB-labeled HRPSiCNTs, and the carried HRP could catalyze the electrochemical reduction of H2O2 with the help of thionine. The high content of HRP in the HRPSiCNTs could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with the increase of SEB in the sample, and exhibited a dynamic range of 0.05-15 ng/mL with a low detection limit (LOD) of 10 pg/mL SEB (at 3σ). Intra- and interassay coefficients of variation were below 10%. In addition, the assay was evaluated with SEB spiked samples including watermelon juice, soymilk, apple juice, and pork food, receiving excellent correlation with results from commercially available enzyme-linked immunosorbent assay (ELISA).

  12. Prophage-Encoded Staphylococcal Enterotoxin A: Regulation of Production in Staphylococcus aureus Strains Representing Different Sea Regions

    Directory of Open Access Journals (Sweden)

    Nikoleta Zeaki

    2015-12-01

    Full Text Available The present study investigates the nature of the link between the staphylococcal enterotoxin A (SEA gene and the lifecycle of Siphoviridae bacteriophages, including the origin of strain variation regarding SEA production after prophage induction. Five strains representing three different genetic lines of the sea region were studied under optimal and prophage-induced growth conditions and the Siphoviridae lifecycle was followed through the phage replicative form copies and transcripts of the lysogenic repressor, cro. The role of SOS response on prophage induction was addressed through recA transcription in a recA-disruption mutant. Prophage induction was found to increase the abundance of the phage replicative form, the sea gene copies and transcripts and enhance SEA production. Sequence analysis of the sea regions revealed that observed strain variances were related to strain capacity for prophage induction, rather than sequence differences in the sea region. The impact of SOS response activation on the phage lifecycle was demonstrated by the absence of phage replicative form copies in the recA-disruption mutant after prophage induction. From this study it emerges that all aspects of SEA-producing strain, the Siphoviridae phage and the food environment must be considered when evaluating SEA-related hazards.

  13. Immunochemical and PCR analysis of Staphylococcus aureus Enterotoxin B (SEB in milk and fruit juices collected in Lahore, Pakistan

    Directory of Open Access Journals (Sweden)

    Dar Nadia

    2013-01-01

    Full Text Available Enterotoxins secreted by S. aureus are known as a food-poisoning agent that is associated with various gastro-intestinal pathological conditions. In this study, a one-step immunodetection method was devised for routine checking of SEB in milk and fruit juices available locally. Antibodies against recombinant SEB were raised, purified, and cross reactivity was checked against clinically important bacteria (Shigella flexneri, Streptococci, Salmonella typhi, Klebsiella and Bacillus subtilis. Purified anti-SEB antibodies were conjugated with gold nanoparticles (Ab-GNPs for direct detection of SEB in samples. SEB (33%, 4.76% and 15% was found in non-sterilized milk (118, sterilized milk (42 and juices (60, respectively. Coagulase, MSA tests and PCR amplification of 725 bp of the SEB gene confirmed the presence of S. aureus in the collected samples positive for SEB. Immunoassay is easy, reliable and less time consuming and will be helpful to detect the SEB in food samples at local level.

  14. Development of an integrated model for heat transfer and dynamic growth of Clostridium perfringens during the cooling of cooked boneless ham.

    Science.gov (United States)

    Amézquita, A; Weller, C L; Wang, L; Thippareddi, H; Burson, D E

    2005-05-25

    Numerous small meat processors in the United States have difficulties complying with the stabilization performance standards for preventing growth of Clostridium perfringens by 1 log10 cycle during cooling of ready-to-eat (RTE) products. These standards were established by the Food Safety and Inspection Service (FSIS) of the US Department of Agriculture in 1999. In recent years, several attempts have been made to develop predictive models for growth of C. perfringens within the range of cooling temperatures included in the FSIS standards. Those studies mainly focused on microbiological aspects, using hypothesized cooling rates. Conversely, studies dealing with heat transfer models to predict cooling rates in meat products do not address microbial growth. Integration of heat transfer relationships with C. perfringens growth relationships during cooling of meat products has been very limited. Therefore, a computer simulation scheme was developed to analyze heat transfer phenomena and temperature-dependent C. perfringens growth during cooling of cooked boneless cured ham. The temperature history of ham was predicted using a finite element heat diffusion model. Validation of heat transfer predictions used experimental data collected in commercial meat-processing facilities. For C. perfringens growth, a dynamic model was developed using Baranyi's nonautonomous differential equation. The bacterium's growth model was integrated into the computer program using predicted temperature histories as input values. For cooling cooked hams from 66.6 degrees C to 4.4 degrees C using forced air, the maximum deviation between predicted and experimental core temperature data was 2.54 degrees C. Predicted C. perfringens growth curves obtained from dynamic modeling showed good agreement with validated results for three different cooling scenarios. Mean absolute values of relative errors were below 6%, and deviations between predicted and experimental cell counts were within 0.37 log10

  15. Thermal inactivation of ileal loop-reactive Clostridium perfringens type A strains in phosphate buffer and beef gravy.

    Science.gov (United States)

    Bradshaw, J G; Peeler, J T; Twedt, R M

    1977-09-01

    The thermal resistance of spore crops produced from each of two ileal loop-reactive strains of Clostridium perfringens type A was determined in two suspending vehicles consisting of 0.067 M (pH 7.0) phosphate buffer and a commercial beef gravy. D115.6 values obtained in buffer and enumerated after pretreatment with sodium ethylenediaminetetraacetate and recovery in plating medium containing lysozyme were two- to threefold greater than those obtained without this treatment. D115.6 values obtained with beef gravy were less than those obtained in buffer with or without lysozyme; however, the D98.9 and D104.4 values were 1.3 to 2 times greater than those obtained in buffer with lysozyme. The z values were within the ranges reported by previous investigators.

  16. The majority of atypical cpb2 genes in Clostridium perfringens isolates of different domestic animal origin are expressed.

    Science.gov (United States)

    Kircanski, Jasmina; Parreira, Valeria R; Whiteside, Samantha; Pei, Yanlong; Prescott, John F

    2012-10-12

    This study examined the prevalence and expression of the "consensus" and the "atypical"cpb2 genes in Clostridium perfringens isolates from cattle, chickens, dogs, goats, horses, pigs and sheep using polymerase chain reaction (PCR), sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western blotting. Almost all porcine isolates (12/14) carried and expressed the consensus form of cpb2 but, when present in 108 non-porcine isolates, the gene was usually the atypical form (40 atypical versus 9 consensus). Western blotting showed expression in 30 of 40 (75%) atypical cpb2-positive isolates, considerably more frequently than reported previously. CPB2 was expressed by almost all (20/21) the consensus cpb2-positive isolates, regardless of source. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Generation and characterization of recombinant bivalent fusion protein r-Cpib for immunotherapy against Clostridium perfringens beta and iota toxemia.

    Science.gov (United States)

    Das, Shreya; Majumder, Saugata; Kingston, Joseph J; Batra, Harsh V

    2016-02-01

    Clostridium perfringens beta (CPB) and iota (CPI) toxaemias result in some of the most lethal forms of haemorrhagic and necrotic enteritis and sudden death syndrome affecting especially neonates. While CPB enterotoxemia is one of the most common forms of clostridial enterotoxemia, CPI enterotoxemia though putatively considered to be rare is an emerging cause of concern. The similarities in clinical manifestation, gross and histopathology findings of both types of toxaemias coupled to the infrequency of CPI toxaemia might lead to symptomatic misidentification with Type C resulting in therapeutic failure due to habitual administration of CPB anti-toxin which is ineffective against CPI. Therefore in the present study, to generate a composite anti-toxin capable of neutralizing both toxaemias, a novel bivalent chimera r-Cpib was constructed by splicing the non-toxic C terminal binding regions of CPB and CPI, via a flexible glycine linker (G4S) by overlap-extension PCR. The fusion protein was characterized for its therapeutic abilities toward CPI and CPB toxin neutralizations. The r-Cpib was found to be non-toxic and could competitively inhibit binding of CPB to host cell receptors thereby reducing its cytotoxicity. Immunization of mice with r-Cpib generated specific antibodies capable of neutralizing the above toxaemias both in vitro and in vivo. Caco-2 cells exposed to a mixture of anti-r-Cpib sera and native CPI or CPB, displayed significantly superior protection against the respective toxins while passive challenge of mice with a similar mixture resulted in 83 and 91% protection against CPI and CPB respectively. Alternatively, mice exposed to a mixture of sham sera and native toxins died within 2-3 days. This work thus demonstrates r-Cpib as a novel bivalent fusion protein capable of efficient immunotherapy against C. perfringens CPI and CPB toxaemia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Effect of different ionizing radiation doses and dose rates, using Cobalt-60 and electrons beam sources, on the staphylococcal enterotoxin inoculated in mechanically deboned chicken meat

    Energy Technology Data Exchange (ETDEWEB)

    Pomarico Neto, Walter; Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Fukuma, Henrique Takuji, E-mail: pbrito@cnen.gov.br, E-mail: hazevedo@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Brazilian Nuclear Energy Commission (LAPOC/CNEN), Pocos de Caldas, MG (Brazil); Kodama, Yasko, E-mail: ykodama@ipen.br [Nuclear and Energy Research Institute (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Miya, Norma Terugo Nago; Pereira, Jose Luiz, E-mail: miya@fea.unicamp.br, E-mail: pereira@fea.unicamp.br [Campinas State University (UNICAMP), SP (Brazil). Dept. of Food Sciences

    2011-07-01

    The purpose of food irradiation is the destruction of present pathogenic microorganisms and the increase of shelf life of foods. To achieve this process, the source of cobalt-60 and the electron accelerator can be used. The mechanically deboned chicken meat (MDCM) is used for the production of traditional meat products, and it may come to present pathogenic microorganisms such as staphylococcus aureus, a bacterium that produces enterotoxin, which causes food poisoning. The objective of this study is to analyze the effect of ionizing irradiation with different doses and dose rates, deriving from different radiation sources, on staphylococcal enterotoxin type B (SEB) in the MDCM. 50 g samples of MDCM were prepared in a batch of 6 kg of MDCM. The samples were contaminated, with the exception of the control, with SEB in amounts of about 100 ng. Then they were conditioned in a transparent bag made of low density polyethylene, frozen at -18{+-}1 deg C overnight and irradiated in these conditions with doses of 0.0 kGy (control), 1.5 kGy and 3.0 kGy, and with three different dose rates, both in the Cobalt-60 and the electron accelerator. The experiments were conducted in quintuplicate. The SEB extraction from the MDCM was performed according to the protocol recommended by the manufacturer of the kit VIDAS Staph Enterotoxin II (bioMerrieux). The principle of mass balance was used to determine the actual amount of SEB removed by irradiation. The treatment that presented the best results was the one with a dose of 1.5 kGy, high dose rate of the electron accelerator. (author)

  19. Effect of different ionizing radiation doses and dose rates, using Cobalt-60 and electrons beam sources, on the staphylococcal enterotoxin inoculated in mechanically deboned chicken meat

    International Nuclear Information System (INIS)

    Pomarico Neto, Walter; Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Fukuma, Henrique Takuji; Kodama, Yasko; Miya, Norma Terugo Nago; Pereira, Jose Luiz

    2011-01-01

    The purpose of food irradiation is the destruction of present pathogenic microorganisms and the increase of shelf life of foods. To achieve this process, the source of cobalt-60 and the electron accelerator can be used. The mechanically deboned chicken meat (MDCM) is used for the production of traditional meat products, and it may come to present pathogenic microorganisms such as staphylococcus aureus, a bacterium that produces enterotoxin, which causes food poisoning. The objective of this study is to analyze the effect of ionizing irradiation with different doses and dose rates, deriving from different radiation sources, on staphylococcal enterotoxin type B (SEB) in the MDCM. 50 g samples of MDCM were prepared in a batch of 6 kg of MDCM. The samples were contaminated, with the exception of the control, with SEB in amounts of about 100 ng. Then they were conditioned in a transparent bag made of low density polyethylene, frozen at -18±1 deg C overnight and irradiated in these conditions with doses of 0.0 kGy (control), 1.5 kGy and 3.0 kGy, and with three different dose rates, both in the Cobalt-60 and the electron accelerator. The experiments were conducted in quintuplicate. The SEB extraction from the MDCM was performed according to the protocol recommended by the manufacturer of the kit VIDAS Staph Enterotoxin II (bioMerrieux). The principle of mass balance was used to determine the actual amount of SEB removed by irradiation. The treatment that presented the best results was the one with a dose of 1.5 kGy, high dose rate of the electron accelerator. (author)

  20. Multiple-Strain Approach and Probabilistic Modeling of Consumer Habits in Quantitative Microbial Risk Assessment: A Quantitative Assessment of Exposure to Staphylococcal Enterotoxin A in Raw Milk.

    Science.gov (United States)

    Crotta, Matteo; Rizzi, Rita; Varisco, Giorgio; Daminelli, Paolo; Cunico, Elena Cosciani; Luini, Mario; Graber, Hans Ulrich; Paterlini, Franco; Guitian, Javier

    2016-03-01

    Quantitative microbial risk assessment (QMRA) models are extensively applied to inform management of a broad range of food safety risks. Inevitably, QMRA modeling involves an element of simplification of the biological process of interest. Two features that are frequently simplified or disregarded are the pathogenicity of multiple strains of a single pathogen and consumer behavior at the household level. In this study, we developed a QMRA model with a multiple-strain approach and a consumer phase module (CPM) based on uncertainty distributions fitted from field data. We modeled exposure to staphylococcal enterotoxin A in raw milk in Lombardy; a specific enterotoxin production module was thus included. The model is adaptable and could be used to assess the risk related to other pathogens in raw milk as well as other staphylococcal enterotoxins. The multiplestrain approach, implemented as a multinomial process, allowed the inclusion of variability and uncertainty with regard to pathogenicity at the bacterial level. Data from 301 questionnaires submitted to raw milk consumers were used to obtain uncertainty distributions for the CPM. The distributions were modeled to be easily updatable with further data or evidence. The sources of uncertainty due to the multiple-strain approach and the CPM were identified, and their impact on the output was assessed by comparing specific scenarios to the baseline. When the distributions reflecting the uncertainty in consumer behavior were fixed to the 95th percentile, the risk of exposure increased up to 160 times. This reflects the importance of taking into consideration the diversity of consumers' habits at the household level and the impact that the lack of knowledge about variables in the CPM can have on the final QMRA estimates. The multiple-strain approach lends itself to use in other food matrices besides raw milk and allows the model to better capture the complexity of the real world and to be capable of geographical

  1. Type II heat-labile enterotoxins from 50 diverse Escherichia coli isolates belong almost exclusively to the LT-IIc family and may be prophage encoded.

    Directory of Open Access Journals (Sweden)

    Michael G Jobling

    Full Text Available Some enterotoxigenic Escherichia coli (ETEC produce a type II heat-labile enterotoxin (LT-II that activates adenylate cyclase in susceptible cells but is not neutralized by antisera against cholera toxin or type I heat-labile enterotoxin (LT-I. LT-I variants encoded by plasmids in ETEC from humans and pigs have amino acid sequences that are ≥ 95% identical. In contrast, LT-II toxins are chromosomally encoded and are much more diverse. Early studies characterized LT-IIa and LT-IIb variants, but a novel LT-IIc was reported recently. Here we characterized the LT-II encoding loci from 48 additional ETEC isolates. Two encoded LT-IIa, none encoded LT-IIb, and 46 encoded highly related variants of LT-IIc. Phylogenetic analysis indicated that the predicted LT-IIc toxins encoded by these loci could be assigned to 6 subgroups. The loci corresponding to individual toxins within each subgroup had DNA sequences that were more than 99% identical. The LT-IIc subgroups appear to have arisen by multiple recombinational events between progenitor loci encoding LT-IIc1- and LT-IIc3-like variants. All loci from representative isolates encoding the LT-IIa, LT-IIb, and each subgroup of LT-IIc enterotoxins are preceded by highly-related genes that are between 80 and 93% identical to predicted phage lysozyme genes. DNA sequences immediately following the B genes differ considerably between toxin subgroups, but all are most closely related to genomic sequences found in predicted prophages. Together these data suggest that the LT-II loci are inserted into lambdoid type prophages that may or may not be infectious. These findings raise the possibility that production of LT-II enterotoxins by ETEC may be determined by phage conversion and may be activated by induction of prophage, in a manner similar to control of production of Shiga-like toxins by converting phages in isolates of enterohemmorhagic E. coli.

  2. Review Over a 3-Year Period of European Union Proficiency Tests for Detection of Staphylococcal Enterotoxins in Food Matrices.

    Science.gov (United States)

    Nia, Yacine; Mutel, Isabelle; Assere, Adrien; Lombard, Bertrand; Auvray, Frederic; Hennekinne, Jacques-Antoine

    2016-04-13

    Staphylococcal food poisoning outbreaks are a major cause of foodborne illnesses in Europe and their notifications have been mandatory since 2005. Even though the European regulation on microbiological criteria for food defines a criterion on staphylococcal enterotoxin (SE) only in cheese and dairy products, European Food Safety Authority (EFSA) data reported that various types of food matrices are involved in staphylococcal food poisoning outbreaks. The European Screening Method (ESM) of European Union Reference Laboratory for Coagulase Positive Staphylococci (EURL CPS) was validated in 2011 for SE detection in food matrices and is currently the official method used for screening purposes in Europe. In this context, EURLCPS is annually organizing Inter-Laboratory Proficiency Testing Trials (ILPT) to evaluate the competency of the European countries' National Reference Laboratories (NRLs) to analyse SE content in food matrices. A total of 31 NRLs representing 93% of European countries participated in these ILPTs. Eight food matrices were used for ILPT over the period 2013-2015, including cheese, freeze-dried cheese, tuna, mackerel, roasted chicken, ready-to-eat food, milk, and pastry. Food samples were spiked with four SE types (i.e., SEA, SEC, SED, and SEE) at various concentrations. Homogeneity and stability studies showed that ILPT samples were both homogeneous and stable. The analysis of results obtained by participants for a total of 155 blank and 620 contaminated samples allowed for evaluation of trueness (>98%) and specificity (100%) of ESM. Further to the validation study of ESM carried out in 2011, these three ILPTs allowed for the assessment of the proficiency of the NRL network and the performance of ESM on a large variety of food matrices and samples. The ILPT design presented here will be helpful for the organization of ILPT on SE detection by NRLs or other expert laboratories.

  3. Review Over a 3-Year Period of European Union Proficiency Tests for Detection of Staphylococcal Enterotoxins in Food Matrices

    Directory of Open Access Journals (Sweden)

    Yacine Nia

    2016-04-01

    Full Text Available Staphylococcal food poisoning outbreaks are a major cause of foodborne illnesses in Europe and their notifications have been mandatory since 2005. Even though the European regulation on microbiological criteria for food defines a criterion on staphylococcal enterotoxin (SE only in cheese and dairy products, European Food Safety Authority (EFSA data reported that various types of food matrices are involved in staphylococcal food poisoning outbreaks. The European Screening Method (ESM of European Union Reference Laboratory for Coagulase Positive Staphylococci (EURL CPS was validated in 2011 for SE detection in food matrices and is currently the official method used for screening purposes in Europe. In this context, EURLCPS is annually organizing Inter-Laboratory Proficiency Testing Trials (ILPT to evaluate the competency of the European countries’ National Reference Laboratories (NRLs to analyse SE content in food matrices. A total of 31 NRLs representing 93% of European countries participated in these ILPTs. Eight food matrices were used for ILPT over the period 2013–2015, including cheese, freeze-dried cheese, tuna, mackerel, roasted chicken, ready-to-eat food, milk, and pastry. Food samples were spiked with four SE types (i.e., SEA, SEC, SED, and SEE at various concentrations. Homogeneity and stability studies showed that ILPT samples were both homogeneous and stable. The analysis of results obtained by participants for a total of 155 blank and 620 contaminated samples allowed for evaluation of trueness (>98% and specificity (100% of ESM. Further to the validation study of ESM carried out in 2011, these three ILPTs allowed for the assessment of the proficiency of the NRL network and the performance of ESM on a large variety of food matrices and samples. The ILPT design presented here will be helpful for the organization of ILPT on SE detection by NRLs or other expert laboratories.

  4. Dynamics of plc gene transcription and α-toxin production during growth of Clostridium perfringens strains with contrasting α-toxin production

    DEFF Research Database (Denmark)

    Abildgaard, Lone; Schramm, Andreas; Rudi, Knut

    2009-01-01

    The aim of the present study was to investigate transcription dynamics of the α-toxin-encoding plc gene relative to two housekeeping genes (gyrA and rplL) in batch cultures of three Clostridium perfringens strains with low, intermediate, and high levels of α-toxin production, respectively. The plc...... transcript level was always low in the low α-toxin producing strain. For the two other strains, plc transcription showed an inducible pattern and reached a maximum level in the late exponential growth phase. The transcription levels were however inversely correlated to α-toxin production for the two strains....... We propose that this discrepancy is due to differences in plc translation rates between the strains and that strain-specific translational rates therefore must be determined before α-toxin production can be extrapolated from transcript levels in C. perfringens....

  5. The application of rumen simulation technique (RUSITEC) for studying dynamics of the bacterial community and metabolome in rumen fluid and the effects of a challenge with Clostridium perfringens.

    Science.gov (United States)

    Wetzels, Stefanie U; Eger, Melanie; Burmester, Marion; Kreienbrock, Lothar; Abdulmawjood, Amir; Pinior, Beate; Wagner, Martin; Breves, Gerhard; Mann, Evelyne

    2018-01-01

    The rumen simulation technique (RUSITEC) is a well-established semicontinuous in vitro model for investigating ruminal fermentation; however, information on the stability of the ruminal bacterial microbiota and metabolome in the RUSITEC system is rarely available. The availability of high resolution methods, such as high-throughput sequencing and metabolomics improve our knowledge about the rumen microbial ecosystem and its fermentation processes. Thus, we used Illumina MiSeq 16S rRNA amplicon sequencing and a combination of direct injection mass spectrometry with a reverse-phase LC-MS/MS to evaluate the dynamics of the bacterial community and the concentration of several metabolites in a RUSITEC experiment as a function of time and in response to a challenge with a pathogenic Clostridium perfringens (C. perfringens) strain. After four days of equilibration, samples were collected on days 5, 6, 7, 10, 12 and 15 of the steady-state and experimental period. From a total of six fermenters, three non-infected fermenters were used for investigating time-dependent alterations; three fermenters were incubated with C. perfringens and compared with the non-infected vessels at days 10, 12 and 15. Along the time-line, there was no statistically significant change of the overall bacterial community, however, some phylotypes were enriched at certain time points. A decrease in Fibrobacter and Elusimicrobia over time was followed by an increase in Firmicutes and Actinobacteria. In contrast, classical fermentation measurements such as pH, redox potential, NH3-N, short chain fatty acids and the concentrations of metabolites determined by metabolomics (biogenic amines, hexoses and amino acids) remained stable throughout the experiment. In response to C. perfringens addition the concentrations of several amino acids increased. Although the overall bacterial community was not altered here either, some minor changes such as an enrichment of Synergistetes and Bacteroidetes were

  6. ENSAYO PRELIMINAR DE LA ACTIVIDAD ANTIBACTERIANA DE EXTRACTOS DE ALLIUM SATIVUM, CORIANDRUM SATIVUM, EUGENIA CARYOPHYLLATA, ORIGANUM VULGARE, ROSMARINUS OFFICINALIS Y THYMUS VULGARIS FRENTE A CLOSTRIDIUM PERFRINGENS

    OpenAIRE

    Ardila Q., Martha I; Vargas A., Andrés F; Pérez C., Jorge E; Mejía G., Luis F

    2009-01-01

    Se evaluó la actividad antibacteriana frente a Clostridium perfringens (cepa ATCC: 13124) por el método de Kirby Bauer en agar SPS de los aceites esenciales o extractos vegetales obtenidos con solventes orgánicos de diferente polaridad a partir de Allium sativum (ajo), Coriandrum sativum (cilantro), Eugenia Caryophyllata (clavo de olor), Origanum vulgare (orégano), Rosmarinus officinalis (romero) y Thymus vulgaris (tomillo), utilizando la vancomicina como control. Los extractos obtenidos por ...

  7. Recurring Necrotic Enteritis Outbreaks in Commercial Broiler Chicken Flocks Strongly Influence Toxin Gene Carriage and Species Richness in the Resident Clostridium perfringens Population

    OpenAIRE

    Marie-Lou Gaucher; Marie-Lou Gaucher; Marie-Lou Gaucher; Gabriel G. Perron; Julie Arsenault; Ann Letellier; Martine Boulianne; Sylvain Quessy

    2017-01-01

    Extensive use of antibiotic growth promoters (AGPs) in food animals has been questioned due to the globally increasing problem of antibiotic resistance. For the poultry industry, digestive health management following AGP withdrawal in Europe has been a challenge, especially the control of necrotic enteritis. Much research work has focused on gut health in commercial broiler chicken husbandry. Understanding the behavior of Clostridium perfringens in its ecological niche, the poultry barn, is k...

  8. Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods

    Directory of Open Access Journals (Sweden)

    E.L. Souza

    2013-01-01

    Full Text Available This study evaluated the influence of the phenolic compounds carvacrol (CAR and thymol (THY on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.

  9. The detection of K88, K99 fimbrial antigen and enterotoxin genes of Escherichia coli isolated from piglets and calves with diarrhoea in Indonesia

    Directory of Open Access Journals (Sweden)

    Supar

    1996-03-01

    Full Text Available Enterotoxigenic Escherichia coli (ETEC strains cause diarrhoeal disease in piglets and calves in Indonesia. These strains possess two virulence factors namely attachment and enterotoxin antigens . These factors could be detected phenotypically and genetically. Haemolytic Escherichia coli (E coli isolates possessing K88 fimbrial antigen associated with 0-group 108 and 149. They were positive for K88 gene and demonstrated their ability to produce heat labile enterotoxin (LT and genetically were all positive for LT gene . Seventeen isolates ofE coli K88 which associated with 0-group 149 were positive forSTb gene, other O-serotypes were negative . Ten isolates of Ecoli K88 which associated with 0-group 108 possessed K88, K99, LT and STa genes, but negative for STb gene . However, phenotypically the K99 antigen and STa toxin were not expressed under laboratory conditions, the reason was not well understood . E. coli K99 strains isolated from calves wit h diarrhoea were all associated with 0-group 9 and produced STa toxin when tested by suckling mousse bioassay. The E. coli K99 calf isolates were all hybridized with K99 and STa gene only . It is likely that K99 gene is associated with STa gene . The DNA hybridization technique is more convenience to be used for confirmation diagnosis of colibacillosis, however, not all veterinary laboratories could perform these tests .

  10. Prevalence and characteristics of Clostridium perfringens and Clostridium difficile in dogs and cats attended in diverse veterinary clinics from the Madrid region.

    Science.gov (United States)

    Álvarez-Pérez, Sergio; Blanco, José L; Harmanus, Celine; Kuijper, Ed J; García, Marta E

    2017-12-01

    Despite extensive research on the epidemiology of pathogenic clostridia in dogs and cats, most published studies focus on a selected animal population and/or a single veterinary medical centre. We assessed the burden of Clostridium perfringens and C. difficile shedding by small animals in 17 veterinary clinics located within the Madrid region (Spain) and differing in size, number and features of animals attended and other relevant characteristics. In addition, we studied the genetic diversity and antibiotic susceptibility of recovered isolates. Selective culture of all fecal specimens collected during a single week from dogs (n = 105) and cats (n = 37) attended in participating clinics yielded C. perfringens/C. difficile from 31%, 4.8% of the dogs, and 20%, 0% of the cats analyzed, respectively, and three dogs yielded both species. Furthermore, 17 animals (15 dogs and two cats) that yielded a positive culture for either species were recruited for a follow-up survey and C. perfringens was again obtained from nine dogs. Considerable differences in prevalence were observed among participating clinics for both clostridial species. C. perfringens isolates (n = 109) belonged to toxinotypes A (97.2%) and E (three isolates from one dog), whereas C. difficile isolates (n = 18) belonged to the toxigenic ribotypes 106 (33.3%) and 154 (16.7%), a 009-like ribotype (33.3%) and an unknown non-toxigenic ribotype (16.7%). Amplified fragment length polymorphism-based fingerprinting classified C. perfringens and C. difficile isolates into 105 and 15 genotypes, respectively, and tested isolates displayed in vitro resistance to benzylpenicillin (2.8%, 88.8%), clindamycin (0%, 16.7%), erythromycin (0.9%, 16.7%), imipenem (1.8%, 100%), levofloxacin (0.9%, 100%), linezolid (5.5%, 0%), metronidazole (4.6%, 0%) and/or tetracycline (7.3%, 0%). All animals from which multiple isolates were retrieved yielded ≥2 different genotypes and/or antimicrobial susceptibility profiles

  11. Bacterial Toxins for Oncoleaking Suicidal Cancer Gene Therapy.

    Science.gov (United States)

    Pahle, Jessica; Walther, Wolfgang

    For suicide gene therapy, initially prodrug-converting enzymes (gene-directed enzyme-producing therapy, GDEPT) were employed to intracellularly metabolize non-toxic prodrugs into toxic compounds, leading to the effective suicidal killing of the transfected tumor cells. In this regard, the suicide gene therapy has demonstrated its potential for efficient tumor eradication. Numerous suicide genes of viral or bacterial origin were isolated, characterized, and extensively tested in vitro and in vivo, demonstrating their therapeutic potential even in clinical trials to treat cancers of different entities. Apart from this, growing efforts are made to generate more targeted and more effective suicide gene systems for cancer gene therapy. In this regard, bacterial toxins are an alternative to the classical GDEPT strategy, which add to the broad spectrum of different suicide approaches. In this context, lytic bacterial toxins, such as streptolysin O (SLO) or the claudin-targeted Clostridium perfringens enterotoxin (CPE) represent attractive new types of suicide oncoleaking genes. They permit as pore-forming proteins rapid and also selective toxicity toward a broad range of cancers. In this chapter, we describe the generation and use of SLO as well as of CPE-based gene therapies for the effective tumor cell eradication as promising, novel suicide gene approach particularly for treatment of therapy refractory tumors.

  12. Safety and efficacy of E coli enterotoxin adjuvant for urease-based rectal immunization against Helicobacter pylori.

    Science.gov (United States)

    Sougioultzis, Stavros; Lee, Cynthia K; Alsahli, Mazen; Banerjee, Subhas; Cadoz, Michel; Schrader, Robert; Guy, Bruno; Bedford, Philip; Monath, Thomas P; Kelly, Ciaran P; Michetti, Pierre

    2002-12-13

    Low dose E. coli heat-labile enterotoxin (LT), delivered orally or enterically, has been used as an adjuvant for Helicobacter pylori (H. pylori) urease in healthy adults. In this study we aim to test the safety and adjuvant efficacy of LT delivered rectally together with recombinant H. pylori urease. Eighteen healthy adults without present or past H. pylori infection were enrolled in a double blind, randomized, ascending dose study to receive either urease (60 mg), or urease (60 mg) + LT (5 or 25 microg). The immunization preparation was administered per rectum on days 0, 14 and 28. Serum, stool and saliva anti-urease and anti-LT IgG and IgA antibodies (Abs) were measured and urease-specific and LT-specific antigen secreting cells (ASCs) were counted in peripheral blood at baseline and 7 (ASC counts) or 14 days (antibody levels) after each dosing. Peripheral blood lymphoproliferation assays were also performed at baseline and at the end of the study. Rectally delivered urease and LT were well tolerated. Among the 12 subjects assigned to urease+LT, 2 (16.7%) developed anti-urease IgG Abs, 1 (8.3%) developed anti-urease IgA Abs, and 3 (25%) showed urease-specific IgA(+) ASCs. Immune responses to LT were more vigorous, especially in subjects exposed to 5 microg LT. In the urease+ 5 microg LT group, anti-LT IgG and IgA Abs developed in 60 and 80% of the subjects, respectively, while LT-specific IgG(+) and IgA(+) ASCs were detected in all subjects. The magnitude of the anti-LT response was much higher than the response to urease. No IgA anti-urease or anti-LT Abs were detected in stool or saliva and lymphocyte proliferative responses to urease were unsatisfactory. In conclusion, rectal delivery of 5 microg LT is safe and induces vigorous systemic anti-LT immune responses. Further studies are needed to determine if LT can be an effective adjuvant for rectally delivered antigens.

  13. Adhesive properties of an outer structure of Clostridium perfringens type A isolated from piglets with with catarrhal enteritis Propriedades adesivas de uma estrutura externa de Clostridium perfringens tipo A isolada de leitões com enterite catarral

    Directory of Open Access Journals (Sweden)

    Elizabeth Pelosi Teixeira

    1999-07-01

    Full Text Available One strain (S32 of Clostridium perfringens type A was isolated from a case of catarrhal enteritis of piglets. This strain was able to adhere to HeLa cells showing an adherence index (AI of 25.15 ± 1.26 (mean ± 1 standard error of the mean. Treatment of the bacterial cells with trypsin (0.25mg/ml decreased in 70%-80% the AI and metaperiodate (10mg/ml abolished completely the adherence, suggesting that the structure responsible for this phenomenon was probably a glycoprotein. Heating of bacterial suspensions (100ºC/5 min before carrying out the adhesion test decreased the AI rendering it equal to the negative controls. Rabbit homologous S32 antiserum inhibited the adherence up to dilutions of 1: 640, at least. The piglet ileal loop assay, carried out with strains S32 and Jab-1 (negative control demonstrated that the strain S32 was able to adhere to the intestinal epithelial cells when examined after Gram staining. Transmission electron microcopy (TEM demonstrated that S32 strain displayed a loose fibrillar material not seen with Jab-1. Stabilization of the bacterial cells with homologous antiserum of strain S32, followed by staining with rhuteniun red, revealed loose long fibrillar material on the outer surface of the cells, that sometimes could be seen spreading out from the cells and linking bacterial cells. The question whether this structure might be an adhesin for this strain of Cl. perfringes type A, perhaps playing a role in the pathogenesis of the catarrhal enteritis of piglets, is dependent on further studies.Uma amostra (S32 de Clostridium perfringens tipo A foi isolada de um caso de enterite catarral em leitões. Esta amostra foi capaz de aderir a células HeLa mostrando um índice de adesão (AI de 25,15 ± 1,26 (media ± 1 erro padrão da media. Tratamento das células bacterianas com tripsina (0,25mg/ml diminuiu 70%-80% e metaperiodato (10mg/ml aboliu significantemente a adesão, sugerindo que a estrutura responsável por esta

  14. Interaction of Clostridium perfringens epsilon-toxin with biological and model membranes: A putative protein receptor in cells.

    Science.gov (United States)

    Manni, Marco M; Sot, Jesús; Goñi, Félix M

    2015-03-01

    Epsilon-toxin (ETX) is a powerful toxin produced by some strains of Clostridium perfringens (classified as types B and D) that is responsible for enterotoxemia in animals. ETX forms pores through the plasma membrane of eukaryotic cells, consisting of a β-barrel of 14 amphipathic β-strands. ETX shows a high specificity for certain cell lines, of which Madin-Darby canine kidney (MDCK) is the first sensitive cell line identified and the most studied one. The aim of this study was to establish the role of lipids in the toxicity caused by ETX and the correlation of its activity in model and biological membranes. In MDCK cells, using cell counting and confocal microscopy, we have observed that the toxin causes cell death mediated by toxin binding to plasma membrane. Moreover, ETX binds and permeabilizes the membranes of giant plasma membrane vesicles (GPMV). However, little effect is observed on protein-free vesicles. The data suggest the essential role of a protein receptor for the toxin in cell membranes. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  16. Use of Plant Extracts as an Effective Manner to Control Clostridium perfringens Induced Necrotic Enteritis in Poultry

    Science.gov (United States)

    Dominguez, J. E.; Chacana, A. P.

    2016-01-01

    Necrotic enteritis (NE) is an important concern in poultry industry since it causes economic losses, increased mortality, reduction of bird welfare, and contamination of chicken products for human consumption. For decades, the use of in-feed antimicrobial growth promoters (AGPs) has been the main strategy to control intestinal pathogens including Clostridium perfringens (CP), the causative agent of NE. However, the use of AGPs in animal diet has been linked to the emergence and transmission of antimicrobial resistance through food-borne microorganisms, which has led to the ban of AGPs in many countries. This scenario has challenged the poultry industry to search for safer alternative products in order to prevent NE. In this context, the utilization of natural plant extracts with antimicrobial properties appears as a promising and feasible tool to control NE in chicken. In this paper, we review the scientific studies analyzing the potential of plant extracts as alternative feed additives to reduce NE in poultry, with focus on two types of plant products that arise as promising candidates: tannins and essential oils. Some of these products showed antimicrobial activity against CP and coccidia in vitro and in vivo and are able to increase productive performance, emulating the bioactive properties of AGPs. PMID:27747227

  17. Roles of Asp179 and Glu270 in ADP-Ribosylation of Actin by Clostridium perfringens Iota Toxin.

    Directory of Open Access Journals (Sweden)

    Alexander Belyy

    Full Text Available Clostridium perfringens iota toxin is a binary toxin composed of the enzymatically active component Ia and receptor binding component Ib. Ia is an ADP-ribosyltransferase, which modifies Arg177 of actin. The previously determined crystal structure of the actin-Ia complex suggested involvement of Asp179 of actin in the ADP-ribosylation reaction. To gain more insights into the structural requirements of actin to serve as a substrate for toxin-catalyzed ADP-ribosylation, we engineered Saccharomyces cerevisiae strains, in which wild type actin was replaced by actin variants with substitutions in residues located on the Ia-actin interface. Expression of the actin mutant Arg177Lys resulted in complete resistance towards Ia. Actin mutation of Asp179 did not change Ia-induced ADP-ribosylation and growth inhibition of S. cerevisiae. By contrast, substitution of Glu270 of actin inhibited the toxic action of Ia and the ADP-ribosylation of actin. In vitro transcribed/translated human β-actin confirmed the crucial role of Glu270 in ADP-ribosylation of actin by Ia.

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

    Science.gov (United States)

    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

  19. The effect of feeding a commercial essential oil product on Clostridium perfringens numbers in the intestine of broiler chickens measured by real-time PCR targeting the α-toxin-encoding gene (plc)

    DEFF Research Database (Denmark)

    Abildgaard, Lone; Højberg, Ole; Schramm, Andreas

    2010-01-01

    Proliferation of Clostridium perfringens type A in the broiler intestinal tract is related to poor growth and litter quality, and can under certain conditions lead to the development of necrotic enteritis (NE), a severe gastrointestinal disease in broilers. The aim of the present study was to inv...... quantification of C. perfringens type A in broilers, a real-time PCR assay, targeting the α-toxin-encoding plc gene, was developed for use in ileal and caecal samples and was shown to be a fast and reliable alternative to conventional plate counting....

  20. Structure of the superantigen staphylococcal enterotoxin B in complex with TCR and peptide-MHC demonstrates absence of TCR-peptide contacts.

    Science.gov (United States)

    Rödström, Karin E J; Elbing, Karin; Lindkvist-Petersson, Karin

    2014-08-15

    Superantigens are immune-stimulatory toxins produced by Staphylococcus aureus, which are able to interact with host immune receptors to induce a massive release of cytokines, causing toxic shock syndrome and possibly death. In this article, we present the x-ray structure of staphylococcal enterotoxin B (SEB) in complex with its receptors, the TCR and MHC class II, forming a ternary complex. The structure, in combination with functional analyses, clearly shows how SEB adopts a wedge-like position when binding to the β-chain of TCR, allowing for an interaction between the α-chain of TCR and MHC. Furthermore, the binding mode also circumvents contact between TCR and the peptide presented by MHC, which enables SEB to initiate a peptide-independent activation of T cells. Copyright © 2014 by The American Association of Immunologists, Inc.

  1. Antimicrobial resistance and detection of the mecA gene besides enterotoxin-encoding genes among coagulase-negative Staphylococci isolated from clam meat of Anomalocardia brasiliana.

    Science.gov (United States)

    Batista, Jacqueline Ellen Camelo; Ferreira, Ewerton Lucena; Nascimento, Danielle Cristina de Oliveira; Ventura, Roberta Ferreira; de Oliveira, Wagner Luis Mendes; Leal, Nilma Cintra; Lima-Filho, José Vitor

    2013-12-01

    The marine clam Anomalocardia brasiliana is a candidate as a sentinel animal to monitor the contamination levels of coliforms in shellfish-harvesting areas of Brazil's northeastern region. The aim of the present study was to search enterotoxin-encoding genes plus the mecA gene among coagulase-negative staphylococci (CNS) isolates from shellfish meats of A. brasiliana. The specimen clam (n=48; 40 clams per sample) was collected during low tide in the bay area of Mangue Seco from April through June 2009, and random samples of chilled and frozen shelled clam meat (n=33; 250 g per sample) were obtained from retail shops from January through March 2012. Seventy-nine CNS isolates were identified, including Staphylococcus xylosus, S. cohnii spp. urealyticus, S. sciuri, and S. lentus. A high percentage of isolates resistant to erythromycin (58.5%), penicillin (51.2%), and tetracycline (43.9%), and the fluoroquinolones levofloxacin (39%) and ciprofloxacin (34.1%) were recorded from those environmental samples. Isolates from retail shops were particularly resistant to oxacillin (55.3%) and penicillin (36.8%). All CNS resistant to oxacillin and/or cefoxitin were positive for the presence of the mecA gene, but phenotypically susceptible to vancomycin. Also, the enterotoxin-encoding genes seg and seh were detected through multiplex-polymerase chain reaction in 77.7% and 88.8% of the isolates from environmental samples, versus 90.5% and 100% of the isolates from retail shops, respectively. The data reveal the risk to public health due to consuming raw or undercooked shellfish containing enterotoxigenic plus methicillin-resistant CNS.

  2. The fecal presence of enterotoxin and F4 genes as an indicator of efficacy of treatment with colistin sulfate in pigs.

    Science.gov (United States)

    Rhouma, Mohamed; Fairbrother, John Morris; Thériault, William; Beaudry, Francis; Bergeron, Nadia; Laurent-Lewandowski, Sylvette; Letellier, Ann

    2017-01-05

    Enterotoxigenic Escherichia coli (ETEC) strains producing multiple enterotoxins are important causes of post-weaning diarrhea (PWD) in pigs. The aim of the present study was to investigate the fecal presence of ETEC enterotoxin as well as F4 and F18 genes as an indicator of colistin sulfate (CS) efficacy for treatment of PWD in pigs. Forty-eight piglets were weaned at the age of 21 days, and were divided into four groups: challenged treated, challenged untreated, unchallenged treated, and unchallenged untreated. Challenge was performed using 10 9  CFU of an ETEC: F4 strain, and treatment was conducted using oral CS at the dose of 50,000 IU/kg. The fecal presence of genes encoding for STa, STb, LT, F4 and F18 was detected using PCR. The PCR amplification of ETEC virulence genes showed that nearly 100% of pigs excreted genes encoding for STa and STb toxins in the feces before the challenge. These genes, in the absence of the gene encoding F4, were considered as a marker for F4-negative ETEC. One day after ETEC: F4 oral challenge pigs in the two challenged groups excreted the genes encoding LT and F4 in the feces. These genes were considered as a marker for F4-positive ETEC. However, the gene encoding F18 was not detected in any fecal samples of the 4 groups throughout the experiment. After only 3 days of successive oral treatment with CS, a significant reduction in both the F4-positive and negative ETEC populations was observed in the challenged treated group compared to the challenged untreated group (p F4-positive and F4-negative ETEC in pigs. However, CS clinical efficiency was correlated with non-detection of F4-positive ETEC in the feces. Furthermore the fecal presence of F4-negative ETEC was not associated with clinical symptoms of post-weaning diarrhea in pigs.

  3. Molecular and epidemiological characterization of staphylococcal foodborne outbreak of Staphylococcus aureus harboring seg, sei, sem, sen, seo, and selu genes without production of classical enterotoxins.

    Science.gov (United States)

    Umeda, Kaoru; Nakamura, Hiromi; Yamamoto, Kaori; Nishina, Nobuko; Yasufuku, Kiyoshi; Hirai, Yuki; Hirayama, Teruo; Goto, Kaoru; Hase, Atsushi; Ogasawara, Jun

    2017-09-01

    Staphylococcal food poisoning is the result of consumption of food contaminated with staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus. To date, 23 SEs and SE-like enterotoxins (SEls) have been described in the literature. They are divided into classical SEs (SEA-SEE) and new SE/SEls (SEG-SElX). Some have proved to be foodborne-inducible, but others remain unidentified. In May 2016, at an elderly group home in Osaka city, Japan, an outbreak from foodborne pathogens occurred among lunch party participants. Within 2h 30min to 4h 40min, 15 of 53 participants presented gastrointestinal symptoms of vomiting, diarrhea, and nausea. A subsequent laboratory investigation detected S. aureus from most stool samples from patients, several left-over food items, a kitchen swab, and hand swabs from two food handlers. Classical SEs was not detected from S. aureus isolates or left-over food items. From examination for the presence of SE/SEl genes of 20 kinds by PCR, seg, sei, sem, sen, seo, and selu genes were detected in almost all isolates. These isolates exhibited identical or closely related types by coagulase type (type VII), Sma I digested pulsed-field gel electrophoresis analysis and multi-locus sequence typing (MLST-CC45 lineage). These results suggest that the foodborne outbreak was caused by S. aureus harboring seg, sei, sem, sen, seo, and selu genes without production of classical SEs. Additionally, some S. aureus isolates from human nasal swabs and healthy human feces harboring seg, sei, sem, sen, seo, and selu genes without production of classical SEs were classified into CC45 lineage using MLST. These findings suggest new SE/SEls as a potential cause of foodborne outbreaks. Copyright © 2017. Published by Elsevier B.V.

  4. Positive Regulation of Staphylococcal Enterotoxin H by Rot (Repressor of Toxin) Protein and Its Importance in Clonal Complex 81 Subtype 1 Lineage-Related Food Poisoning.

    Science.gov (United States)

    Sato'o, Yusuke; Hisatsune, Junzo; Nagasako, Yuria; Ono, Hisaya K; Omoe, Katsuhiko; Sugai, Motoyuki

    2015-11-01

    We previously demonstrated the clonal complex 81 (CC81) subtype 1 lineage is the major staphylococcal food poisoning (SFP)-associated lineage in Japan (Y. Sato'o et al., J Clin Microbiol 52:2637-2640, 2014, http://dx.doi.org/10.1128/JCM.00661-14). Strains of this lineage produce staphylococcal enterotoxin H (SEH) in addition to SEA. However, an evaluation of the risk for the recently reported SEH has not been sufficiently conducted. We first searched for staphylococcal enterotoxin (SE) genes and SE proteins in milk samples that caused a large SFP outbreak in Japan. Only SEA and SEH were detected, while there were several SE genes detected in the samples. We next designed an experimental model using a meat product to assess the productivity of SEs and found that only SEA and SEH were detectably produced in situ. Therefore, we investigated the regulation of SEH production using a CC81 subtype 1 isolate. Through mutant analysis of global regulators, we found the repressor of toxin (Rot) functioned oppositely as a stimulator of SEH production. SEA production was not affected by Rot. seh mRNA expression correlated with rot both in media and on the meat product, and the Rot protein was shown to directly bind to the seh promoter. The seh promoter sequence was predicted to form a loop structure and to hide the RNA polymerase binding sequences. We propose Rot binds to the promoter sequence of seh and unfolds the secondary structure that may lead the RNA polymerase to bind the promoter, and then seh mRNA transcription begins. This alternative Rot regulation for SEH may contribute to sufficient toxin production by the CC81 subtype 1 lineage in foods to induce SFP. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. [The staphylococcal enterotoxin burden determines the ultrastructure of ciliated epithelia and inflammatory changes in maxillary sinus mucosa of rabbits].

    Science.gov (United States)

    Wei, Hongqi; Zhu, Zhengwen; Cao, Zhongsheng; Liu, Zhiyong; Wu, Xiaofan; Yuan, Hui

    2014-12-01

    To investigate the ultrastructure of ciliated epithelia and inflammatory changes upon repeated exposure to staphylococcal enterotoxin A (SEA) of different concentrations in the maxillary sinus mucosa of rabbits. The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEA group and high-dose SEA group. The low-dose SEA group and high-dose SEA group received daily injections of 0.6 ng of SEA (2 ml) and 60 ng of SEA (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as control. Six rabbits chosen randomly in two groups were examined by computed tomography (CT) scans and then sacrificed to obtain the sinus mucosa from the two-side of maxillary sinuses for histological assessment on days 3, 7, 14 and 28. To characterize the inflammatory changes of the sinus mucosa examined using light microscope, hematoxylin and eosin (HE) and toluidine blue staining was performed. Scanning and transmission electron microscopy were performed to observe ultrastructure of ciliated epithelia in the maxillary sinus mucosa. SPSS 13.0 software was used to analyze the data. On days 14 and 28, CT images showed opacification of the left maxillary sinus in the high-dose SEA group. The percentage of epithelial disruption was (22.73 ± 5.72) % and (30.79 ± 4.30)% in the high-dose SEA group respectively, and were significantly greater than those in the low-dose SEA group (5.12% ± 1.98% and 5.38% ± 1.64%, q value was 10.079 and 19.132) and control group (4.08% ± 1.29% and 4.81% ± 1.62%, q value was 11.016 and 19.592, respectively, all P microscope, loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were found, an obvious stretching of the endoplasmic reticulum and an obvious turgescence of the mitochondria was also observed. However, in the low-dose SEA group on days 14 and 28, CT scan of the left maxillary sinus showed transparency; light

  6. Alterações fisiológicas do sistema nervoso central de rã pelas toxinas de Cl. perfringens, Cl. oedematiens e Cl. septicum

    Directory of Open Access Journals (Sweden)

    Genésio Pacheco

    1947-09-01

    Full Text Available The authors carried on experiences in order to confirm the neurotoxic theory of gas gangrene explained by Pacheco & Costa, uning preparations of isolated cord-posterior train of Leptodactylus ocellatus as described by OZORIO DE ALMEIDA & Cols. Frogs were intoxicated 3 days before the test with parcially purified toxins of Cl. perfringens, Cl. oedematiens and Cl. septicum. The intoxication produced a shortening of spinal reflexes duration time of such preparations, showing a typical alteration of the reflex activity of the spinal cord.

  7. Impact of Clean-Label Antimicrobials and Nitrite Derived from Natural Sources on the Outgrowth of Clostridium perfringens during Cooling of Deli-Style Turkey Breast.

    Science.gov (United States)

    King, Amanda M; Glass, Kathleen A; Milkowski, Andrew L; Sindelar, Jeffrey J

    2015-05-01

    Organic acids and sodium nitrite have long been shown to provide antimicrobial activity during chilling of cured meat products. However, neither purified organic acids nor NaNO2 is permitted in products labeled natural and both are generally avoided in clean-label formulations; efficacy of their replacement is not well understood. Natural and clean-label antimicrobial alternatives were evaluated in both uncured and in alternative cured (a process that uses natural sources of nitrite) deli-style turkey breast to determine inhibition of Clostridium perfringens outgrowth during 15 h of chilling. Ten treatments of ground turkey breast (76% moisture, 1.2% salt) included a control and four antimicrobials: 1.0% tropical fruit extract, 0.7% dried vinegar, 1.0% cultured sugar-vinegar blend, and 2.0% lemon-vinegar blend. Each treatment was formulated without (uncured) and with nitrite (PCN; 50 ppm of NaNO2 from cultured celery juice powder). Treatments were inoculated with C. perfringens spores (three-strain mixture) to yield 2.5 log CFU/g. Individual 50-g portions were vacuum packaged, cooked to 71.1°C, and chilled from 54.4 to 26.7°C in 5 h and from 26.7 to 7.2°C in an additional 10 h. Triplicate samples were assayed for growth of C. perfringens at predetermined intervals by plating on tryptose-sulfite-cycloserine agar. Uncured control and PCN-only treatments allowed for 4.6- and 4.2-log increases at 15 h, respectively, and although all antimicrobial treatments allowed less outgrowth than uncured and PCN, the degree of inhibition varied. The 1.0% fruit extract and 1.0% cultured sugar-vinegar blend were effective at controlling populations at or below initial levels, whether or not PCN was included. Without PCN, 0.7% dried vinegar and 2.0% lemon-vinegar blend allowed for 2.0- and 2.5-log increases, respectively, and ∼1.5-log increases with PCN. Results suggest using clean-label antimicrobials can provide for safe cooling following the study parameters, and greater

  8. The application of rumen simulation technique (RUSITEC for studying dynamics of the bacterial community and metabolome in rumen fluid and the effects of a challenge with Clostridium perfringens.

    Directory of Open Access Journals (Sweden)

    Stefanie U Wetzels

    Full Text Available The rumen simulation technique (RUSITEC is a well-established semicontinuous in vitro model for investigating ruminal fermentation; however, information on the stability of the ruminal bacterial microbiota and metabolome in the RUSITEC system is rarely available. The availability of high resolution methods, such as high-throughput sequencing and metabolomics improve our knowledge about the rumen microbial ecosystem and its fermentation processes. Thus, we used Illumina MiSeq 16S rRNA amplicon sequencing and a combination of direct injection mass spectrometry with a reverse-phase LC-MS/MS to evaluate the dynamics of the bacterial community and the concentration of several metabolites in a RUSITEC experiment as a function of time and in response to a challenge with a pathogenic Clostridium perfringens (C. perfringens strain. After four days of equilibration, samples were collected on days 5, 6, 7, 10, 12 and 15 of the steady-state and experimental period. From a total of six fermenters, three non-infected fermenters were used for investigating time-dependent alterations; three fermenters were incubated with C. perfringens and compared with the non-infected vessels at days 10, 12 and 15. Along the time-line, there was no statistically significant change of the overall bacterial community, however, some phylotypes were enriched at certain time points. A decrease in Fibrobacter and Elusimicrobia over time was followed by an increase in Firmicutes and Actinobacteria. In contrast, classical fermentation measurements such as pH, redox potential, NH3-N, short chain fatty acids and the concentrations of metabolites determined by metabolomics (biogenic amines, hexoses and amino acids remained stable throughout the experiment. In response to C. perfringens addition the concentrations of several amino acids increased. Although the overall bacterial community was not altered here either, some minor changes such as an enrichment of Synergistetes and

  9. Bacterial spores as possible contaminants of biomedical materials and devices. [Bacillus anthracis, clostridium botulinum, C. perfringens, C. tetani

    Energy Technology Data Exchange (ETDEWEB)

    Grecz, N; Kang, T

    1973-01-01

    Destruction of spores on biomedical devices in drugs, and biologicals is essential for prevention of infection of patients with pathogenic sporeformers. Of particular concern are Clostridium tetani, C. perfringens, C. botulinum, Bacillus anthracis and other sporeforming pathogens. Spores are ubiquitous in nature and contamination of biomedical devices varies depending on manufacturing process, handling, raw materials and other variables. In the last 20 years the number of cases per year of specific notifiable diseases in the United States was as follows: tetanus, 120 to 500 cases, botulism, 7 to 47 cases, and anthrax, 2 to 10 cases. Gas gangrene is caused by a mixed flora consisting predominantly of sporeformers. C botulinum, which usually acts as saprophytic agent of food poisoning, may also initiate pathogenic processes; there are nine cases on record in the United States of botulism wound infections almost half of which ended in death. The spores of these organisms are distinguished by high radiation resistance and their erradication often requires severe radiation treatments. Representative bacterial spores in various suspending media show D/sub 10/ values (dose necessary to destroy 90 percent of a given population) ranging from approximately 0.1 to 0.4 Mrad. Some viruses show D/sub 10/ values up to greater than 1 Mrad. The D/sub 10/-values of spores vary depending on physical, chemical and biological factors. This variability is important in evaluation and selection of biological indicator organisms. Radiation sterilization of biomedical devices and biomedical materials must provide safety from infectious microorganisms including radiation resistant spores and viruses.

  10. Diverse modes of galacto-specific carbohydrate recognition by a family 31 glycoside hydrolase from Clostridium perfringens.

    Directory of Open Access Journals (Sweden)

    Julie M Grondin

    Full Text Available Clostridium perfringens is a commensal member of the human gut microbiome and an opportunistic pathogen whose genome encodes a suite of putative large, multi-modular carbohydrate-active enzymes that appears to play a role in the interaction of the bacterium with mucin-based carbohydrates. Among the most complex of these is an enzyme that contains a presumed catalytic module belonging to glycoside hydrolase family 31 (GH31. This large enzyme, which based on its possession of a GH31 module is a predicted α-glucosidase, contains a variety of non-catalytic ancillary modules, including three CBM32 modules that to date have not been characterized. NMR-based experiments demonstrated a preference of each module for galacto-configured sugars, including the ability of all three CBM32s to recognize the common mucin monosaccharide GalNAc. X-ray crystal structures of the CpGH31 CBM32s, both in apo form and bound to GalNAc, revealed the finely-tuned molecular strategies employed by these sequentially variable CBM32s in coordinating a common ligand. The data highlight that sequence similarities to previously characterized CBMs alone are insufficient for identifying the molecular mechanism of ligand binding by individual CBMs. Furthermore, the overlapping ligand binding profiles of the three CBMs provide a fail-safe mechanism for the recognition of GalNAc among the dense eukaryotic carbohydrate networks of the colonic mucosa. These findings expand our understanding of ligand targeting by large, multi-modular carbohydrate-active enzymes, and offer unique insights into of the expanding ligand-binding preferences and binding site topologies observed in CBM32s.

  11. Comparative genomics of four closely related Clostridium perfringens bacteriophages reveals variable evolution among core genes with therapeutic potential

    Directory of Open Access Journals (Sweden)

    Siragusa Gregory R

    2011-06-01

    Full Text Available Abstract Background Because biotechnological uses of bacteriophage gene products as alternatives to conventional antibiotics will require a thorough understanding of their genomic context, we sequenced and analyzed the genomes of four closely related phages isolated from Clostridium perfringens, an important agricultural and human pathogen. Results Phage whole-genome tetra-nucleotide signatures and proteomic tree topologies correlated closely with host phylogeny. Comparisons of our phage genomes to 26 others revealed three shared COGs; of particular interest within this core genome was an endolysin (PF01520, an N-acetylmuramoyl-L-alanine amidase and a holin (PF04531. Comparative analyses of the evolutionary history and genomic context of these common phage proteins revealed two important results: 1 strongly significant host-specific sequence variation within the endolysin, and 2 a protein domain architecture apparently unique to our phage genomes in which the endolysin is located upstream of its associated holin. Endolysin sequences from our phages were one of two very distinct genotypes distinguished by variability within the putative enzymatically-active domain. The shared or core genome was comprised of genes with multiple sequence types belonging to five pfam families, and genes belonging to 12 pfam families, including the holin genes, which were nearly identical. Conclusions Significant genomic diversity exists even among closely-related bacteriophages. Holins and endolysins represent conserved functions across divergent phage genomes and, as we demonstrate here, endolysins can have significant variability and host-specificity even among closely-related genomes. Endolysins in our phage genomes may be subject to different selective pressures than the rest of the genome. These findings may have important implications for potential biotechnological applications of phage gene products.

  12. Relative disease susceptibility and clostridial toxin antibody responses in three commercial broiler lines co-infected with Clostridium perfringens and Eimeria maxima using an experimental model of necrotic enteritis

    Science.gov (United States)

    Necrotic enteritis is an enteric disease of poultry resulting from infection by Clostridium perfringens with co-infection by Eimeria spp. constituting a major risk factor for disease pathogenesis. This study compared three commercial broiler chicken lines using an experimental model of necrotic ente...

  13. Effects of Bacillus licheniformis on the growth performance and expression of lipid metabolism-related genes in broiler chickens challenged with Clostridium perfringens-induced necrotic enteritis.

    Science.gov (United States)

    Zhou, Mengjia; Zeng, Dong; Ni, Xueqin; Tu, Teng; Yin, Zhongqiong; Pan, Kangcheng; Jing, Bo

    2016-03-08

    Necrotic enteritis (NE), caused by Clostridium perfringens, has cost the poultry industry $2 billion in losses. This study aimed to investigate the effect of Bacillus licheniformis as dietary supplement on the growth, serum antioxidant status, and expression of lipid-metabolism genes of broiler chickens with C. perfringens-induced NE. A total of 240 one-day-old broilers were randomly grouped into four: a negative control, an NE experimental model (PC), chickens fed a diet supplemented with 30 % of fishmeal from day 14 onwards and challenged with coccidiosis vaccine (FC), and NE group supplied with feed containing 1.0 × 10(6) CFU/g B. licheniformis (BL). Body weight gain, feed conversion ratio, serum antioxidant status, and lipid-metabolism-gene expression were analyzed. In the PC group, FCR increased significantly whereas serum catalase and glutathione peroxidase activity decreased compared with NC group. Dietary B. licheniformis supplementation improved FCR and oxidative stress in experimental avian NE. Using Bacillus licheniformis as a direct-fed microbial (DFM) could also significantly upregulate catabolism-related genes, namely, peroxisome proliferator-activated receptor-α and carnitine palmitoyltransferase-1, in livers and changed the expression of lipid-anabolism genes. These results suggested that dietary B. licheniformis supplementation can enhance growth and antioxidant ability, as well as change the expression of genes related to fatty-acid synthesis and oxidation in the livers of NE-infected broilers.

  14. Necrotic enteritis locus 1 diguanylate cyclase and phosphodiesterase (cyclic-di-GMP) gene mutation attenuates virulence in an avian necrotic enteritis isolate of Clostridium perfringens.

    Science.gov (United States)

    Parreira, Valeria R; Ojha, Shivani; Lepp, Dion; Mehdizadeh Gohari, Iman; Zhou, Hongzhuan; Susta, Leonardo; Gong, Jianhua; Prescott, John F

    2017-09-01

    Necrotic enteritis (NE) caused by netB-positive strains of Clostridium perfringens is an important disease of intensively-reared broiler chickens. It is widely controlled by antibiotic use, but this practice that has come under increasing scrutiny and alternative approaches are required. As part of the search for alternative approaches over the last decade, advances have been made in understanding its pathogenesis but much remains to be understood and applied to the control of NE. The objective of this work was to assess the effect on virulence of mutation of the cyclic-di-GMP signaling genes present on the large pathogenicity locus (NELoc-1) in the tcp-encoding conjugative virulence plasmid, pNetB. For this purpose, the diguanylate cyclase (dgc) and phosphodiesterase (pde) genes were individually insertionally inactivated and the two mutants were subsequently complemented with their respective genes. Southern blotting showed that a single gene insertion was present. Mutation of either gene resulted in almost total attenuation of the mutants to cause NE in experimentally-infected broiler chickens, which was fully restored in each case by complementation of the respective mutated gene. Production of NetB-associated cytotoxicity for Leghorn male hepatoma (LMH) cells was unaffected in mutants. We conclude that the cyclic-di-GMP signaling system is important in controlling virulence in a NE C. perfringens strain and might be a target for control of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Assessment of Enterotoxin Production and Cross-Contamination of Staphylococcus aureus between Food Processing Materials and Ready-To-Eat Cooked Fish Paste.

    Science.gov (United States)

    Tango, Charles Nkufi; Hong, Sung-Sam; Wang, Jun; Oh, Deog-Hwan

    2015-12-01

    This study evaluated Staphylococcus aureus growth and subsequent staphylococcal enterotoxin A production in tryptone soy broth and on ready-to-eat cooked fish paste at 12 to 37 °C, as well as cross-contamination between stainless steel, polyethylene, and latex glove at room temperature. A model was developed using Barany and Roberts's growth model, which satisfactorily described the suitable growth of S. aureus with R(2)-adj from 0.94 to 0.99. Except at 12 °C, S. aureus cells in TSB presented a lag time lower (14.64 to 1.65 h), grew faster (0.08 to 0.31 log CFU/h) and produced SEA at lower cell density levels (5.65 to 6.44 log CFU/mL) compare to those inoculated on cooked fish paste with data of 16.920 to 1.985 h, 0.02 to 0.23 log CFU/h, and 6.19 to 7.11 log CFU/g, respectively. Staphylococcal enterotoxin type A (SEA) visual immunoassay test showed that primary SEA detection varied considerably among different storage temperature degrees and media. For example, it occurred only during exponential phase at 30 and 37 °C in TSB, but in cooked fish paste it took place at late exponential phase of S. aureus growth at 20 and 25 °C. The SEA detection test was negative on presence of S. aureus on cooked fish paste stored at 12 and 15 °C, although cell density reached level of 6.12 log CFU/g at 15 °C. Cross-contamination expressed as transfer rate of S. aureus from polyethylene surface to cooked fish paste surface was slower than that observed with steel surface to cooked fish paste under same conditions. These results provide helpful information for controlling S. aureus growth, SEA production and cross-contamination during processing of cooked fish paste. © 2015 Institute of Food Technologists®

  16. Characteristics of enterotoxin distribution, hemolysis, lecithinase, and starch hydrolysis of Bacillus cereus isolated from infant formulas and ready-to-eat foods.

    Science.gov (United States)

    Hwang, Ji-Yeon; Park, Jong-Hyun

    2015-03-01

    Bacillus cereus is a ubiquitous environmental microbe implicated as a main cause of food poisoning with various symptoms, depending on the strain type and the isolation source. In this study, the potential virulence factors and biochemical properties of B. cereus isolated from infant formulas and ready-to-eat (RTE) foods were analyzed and compared. A total of 347 B. cereus strains were isolated and identified from 687 infant food formulas and RTE food samples. All the isolates had one or more enterotoxin genes, and one-half of the strains had all 3 enterotoxin genes (hbl, nhe, and cytK) that are involved in food poisoning in humans. Here, all the 3 genes were detected in 50% of the B. cereus isolates from RTE foods and only 14% of the isolates were identified from infant formulas. The latter harbored low cytK and bceT, and very low hbl genes. Most B. cereus isolates possessed the hemolysis gene, but not the ces gene. The infant formula isolates showed stronger hemolysis activity than the other isolates. In addition, 26% of the total isolates showed low lecithinase activities and 10% showed high lecithinase activities. A greater number of isolates from the infant formula showed high lecithinase activity than those from the RTE foods. Approximately 83% of the isolates were positive and 17% were negative for starch hydrolysis. Over 90% of the RTE food isolates and only 35% of the infant formula isolates were positive for starch hydrolysis. However, all the strains possessed nhe, but their harboring patterns of hbl and cytK were significantly different. Most starch-hydrolyzing strains possessed hbl, but only 23% nonstarch-hydrolyzing isolates possessed this gene. Moreover, very low nonstarch hydrolyzing strains harbored cytK. Most nonstarch-hydrolyzing isolates showed high lecithinase and strong hemolysis activities, and very low hbl and cytK harboring. In summary, most infant formula isolates showed stronger hemolysis and higher lecithinase activities with lower

  17. A highly sensitive fluorescence resonance energy transfer aptasensor for staphylococcal enterotoxin B detection based on exonuclease-catalyzed target recycling strategy

    International Nuclear Information System (INIS)

    Wu, Shijia; Duan, Nuo; Ma, Xiaoyuan; Xia, Yu; Wang, Hongxin; Wang, Zhouping

    2013-01-01

    Graphical abstract: -- Highlights: •An ultrasensitive FRET aptasensor was developed for staphylococcal enterotoxin B determination. •SEB was recognized by SEB aptamer with high affinity and specificity. •The Mn 2+ doped NaYF 4 :Yb/Er UCNPs used as donor to quencher dye (BHQ 3 ) in new FRET. •The fluorescence intensity was prominently amplified using an exonuclease-catalyzed target recycling strategy. -- Abstract: An ultrasensitive fluorescence resonance energy transfer (FRET) bioassay was developed to detect staphylococcal enterotoxin B (SEB), a low molecular exotoxin, using an aptamer-affinity method coupled with upconversion nanoparticles (UCNPs)-sensing, and the fluorescence intensity was prominently enhanced using an exonuclease-catalyzed target recycling strategy. To construct this aptasensor, both fluorescence donor probes (complementary DNA 1 –UCNPs) and fluorescence quencher probes (complementary DNA 2 –Black Hole Quencher 3 (BHQ 3 )) were hybridized to an SEB aptamer, and double-strand oligonucleotides were fabricated, which quenched the fluorescence of the UCNPs via FRET. The formation of an aptamer–SEB complex in the presence of the SEB analyte resulted in not only the dissociation of aptamer from the double-strand DNA but also both the disruption of the FRET system and the restoration of the UCNPs fluorescence. In addition, the SEB was liberated from the aptamer–SEB complex using exonuclease I, an exonuclease specific to single-stranded DNA, for analyte recycling by selectively digesting a particular DNA (SEB aptamer). Based on this exonuclease-catalyzed target recycling strategy, an amplified fluorescence intensity could be produced using different SEB concentrations. Using optimized experimental conditions produced an ultrasensitive aptasensor for the detection of SEB, with a wide linear range of 0.001–1 ng mL −1 and a lower detection limit (LOD) of 0.3 pg mL −1 SEB (at 3σ). The fabricated aptasensor was used to measure SEB in a

  18. Distinct cytokine profiles of circulating mononuclear cells stimulated with Staphylococcus aureus enterotoxin A in vitro during early and late episodes of chronic osteomyelitis

    Directory of Open Access Journals (Sweden)

    Gabriella Freitas Ferreira

    2012-05-01

    Full Text Available We investigated the cytokine profile of peripheral mononuclear cells from chronic osteomyelitis (OST patients following in vitro stimulation with staphylococcal enterotoxin A (SEA. We demonstrate that stimulation with SEA induced prominent lymphocyte proliferation and high levels of tumour necrosis factor (TNF-α, interleukin (IL-4 and IL-10 secretion in both OST and non-infected individuals (NI. Even though stimulation with SEA had no impact on IL-6 production in either patient group, the baseline level of IL-6 production by cells from OST patients was always significantly less than that produced by cells from NI. After classifying the osteomyelitic episodes based on the time after the last reactivation event as "early" (1-4 months or "late" osteomyelitis (5-12 months, we found that increased levels of TNF-α and IL-4 in combination with decreased levels of IL-6 were observed in the early episodes. By contrast, increased levels of IL-10, IL-2 and IL-6 were hallmarks of late episodes. Our data demonstrate that early osteomyelitic episodes are accompanied by an increased frequency of "high producers" of TNF-α and IL-4, whereas late events are characterised by increased frequencies of "high producers" of IL-10, IL-6 and IL-2. These findings demonstrate the distinct cytokine profiles in chronic osteomyelitis, with a distinct regulation of IL-6 production during early and late episodes.

  19. Frequency of enterotoxins, toxic shock syndrome toxin-1, and biofilm formation genes in Staphylococcus aureus isolates from cows with mastitis in the Northeast of Brazil.

    Science.gov (United States)

    Costa, F N; Belo, N O; Costa, E A; Andrade, G I; Pereira, L S; Carvalho, I A; Santos, R L

    2018-06-01

    Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.

  20. Involvement of protein kinase C in the mechanism of action of Escherichia coli heat-stable enterotoxin (STa) in a human colonic carcinoma cell line, COLO-205

    International Nuclear Information System (INIS)

    Gupta, Dyuti Datta; Saha, Subhrajit; Chakrabarti, Manoj K.

    2005-01-01

    The present study was undertaken to determine the involvement of calcium-protein kinase C pathway in the mechanism of action of Escherichia coli heat stable enterotoxin (STa) apart from STa-induced activation of guanylate cyclase in human colonic carcinoma cell line COLO-205, which was used as a model cultured cell line to study the mechanism of action of E. coli STa. In response to E. coli STa, protein kinase C (PKC) activity was increased in a time-dependent manner with its physical translocation from cytosol to membrane. Inhibition of the PKC activity in membrane fraction and inhibition of its physical translocation in response to IP 3 -mediated calcium release inhibitor dantrolene suggested the involvement of intracellular store depletion in the regulation of PKC activity. Among different PKC isoforms, predominant involvement of calcium-dependent protein kinase C (PKCα) was specified using isotype-specific pseudosubstrate, which showed pronounce enzyme activity. Inhibition of enzyme activity by PKCα-specific inhibitor Goe6976 and immunoblott study employing isotype-specific antibody further demonstrated the involvement of calcium-dependent isoform of PKC in the mechanism of action of E. coli STa. Moreover, inhibition of guanylate cyclase activity by PKCα-specific inhibitor Goe6976 suggested the involvement of PKCα in the regulation of guanylate cyclase activity

  1. Chimeric anti-staphylococcal enterotoxin B antibodies and lovastatin act synergistically to provide in vivo protection against lethal doses of SEB.

    Directory of Open Access Journals (Sweden)

    Mulualem E Tilahun

    Full Text Available Staphylococcal enterotoxin B (SEB is one of a family of toxins secreted by Staphylococcus aureus that act as superantigens, activating a large fraction of the T-cell population and inducing production of high levels of inflammatory cytokines that can cause toxic shock syndrome (TSS and death. Extracellular engagement of the TCR of T-cells and class II MHC of antigen presenting cells by SEB triggers the activation of many intracellular signaling processes. We engineered chimeric antibodies to block the extracellular engagement of cellular receptors by SEB and used a statin to inhibit intracellular signaling. Chimeric human-mouse antibodies directed against different neutralizing epitopes of SEB synergistically inhibited its activation of human T-cells in vitro. In the in vivo model of lethal toxic shock syndrome (TSS in HLA-DR3 transgenic mice, two of these antibodies conferred significant partial protection when administered individually, but offered complete protection in a synergistic manner when given together. Similarly, in vivo, lovastatin alone conferred only partial protection from TSS similar to single anti-SEB antibodies. However, used in combination with one chimeric neutralizing anti-SEB antibody, lovastatin provided complete protection against lethal TSS in HLA-DR3 transgenic mice. These experiments demonstrate that in vivo protection against lethal doses of SEB can be achieved by a statin of proven clinical safety and chimeric human-mouse antibodies, agents now widely used and known to be of low immunogenicity in human hosts.

  2. Effects of tetrodotoxin and ion replacements on the short-circuit current induced by Escherichiacoli heat stable enterotoxin across small intestine of the gerbil (Gerbillus cheesmani

    Directory of Open Access Journals (Sweden)

    Fawzia Yaqoub Al-Balool

    2004-03-01

    Full Text Available The effects of mucosally added Escherichia coli heat stable enterotoxin (STa 30 ng ml-1 on the basal short-circuit current (Isc in µA cm-2 across stripped and unstripped sheets of jejuna and ilea taken from fed, starved (4 days, water ad lib and undernourished (50% control food intake for 21 days gerbil (Gerbillus cheesmani were investigated. The effect of neurotoxin tetrodotoxin (TTX 10 µM and the effects of replacing chloride by gluconate or the effects of removing bicarbonate from bathing buffers on the maximum increase in Isc induced by STa were also investigated. The maximum increase in Isc which resulted from the addition of STa were significantly higher in jejuna and ilea taken from starved and undernourished gerbils when compared with the fed control both using stripped and unstripped sheets. In the two regions of the small intestine taken from fed and starved animals TTX reduced the maximum increase in Isc induced by STa across unstripped sheets only. Moreover in jejuna and ilea taken from undernourished gerbils TTX reduced significantly the maximum increase in Isc induced by STa across stripped and unstripped sheets. Replacing chloride by gluconate decreased the maximum increase in Isc induced by STa across jejuna and ilea taken from undernourished gerbils only. Removing bicarbonates from bathing buffer decreased the maximum increase in Isc across the jejuna and ilea taken from starved and undernourished gerbils.

  3. Immunoprophylactic strategies against enterotoxemia caused by Clostridium perfringens type D in goats Estratégias imunoprofiláticas contra enterotoxemia causada por Clostridium perfringens tipo D em caprinos

    Directory of Open Access Journals (Sweden)

    Josir Laine A. Veschi

    2006-03-01

    Full Text Available The serological response to an experimental vaccine against Clostridium perfringens type D enterotoxemia was evaluated in four groups of goats. Group 1 received colostrum from unvaccinated cows and no vaccine. Groups 2, 3 and 4 received colostrum from vaccinated cows. In addition, Groups 3 and 4 received a vaccine dose at 80 days of age, and Group 4 received a second vaccine dose at 120 days of age. Serum antibody levels were determined by ELISA in cows before and after calving, and in goats at 3, 80, 120 and 160 days of age. No significant difference in serum antibody levels was observed between vaccinated and unvaccinated cows, or between the four groups of goats evaluated at 3 days of life. Groups 3 and 4 presented mean antibody titers of 0.6 and 1.1 IU/ml, respectively, 40 days after first vaccination. The vaccine response of Group 4 was 1.8 IU/ml 40 days after the booster dose and was higher than that observed for Group 3 (0.2 IU/ml. Thus, in the proposed regimen the use of heterologous colostrum did not induce passive immunization in goat kids. However, first vaccination and a booster dose after 40 days triggered satisfactory antibody levels.Foi avaliada a resposta sorológica de vacina experimental contra a enterotoxemia em quatro grupos de caprinos. O Grupo 1 recebeu colostro de vacas não vacinadas e nenhuma dose de vacina. Os Grupos 2, 3 e 4 receberam colostro de vacas vacinadas, e uma dose de vacina aos 80 dias de idade nos Grupos 3 e 4. O Grupo 4 recebeu a segunda dose de vacina aos 120 dias de idade. Os níveis de anticorpos séricos foram avaliados pelo ELISA nas vacas antes e depois do parto e nos caprinos aos 3, 80, 120 e 160 dias de idade. Não houve diferença significativa nos níveis de anticorpos séricos das vacas vacinadas e não vacinadas, assim como entre os quatro grupos de caprinos avaliados aos três dias de vida. Os Grupos 3 e 4 apresentaram títulos médios de anticorpos de 0,6 UI/mL e 1,1 UI/mL, respectivamente

  4. Optimization of culture conditions to improve the expression level of beta1–epsilon toxin of Clostridium perfringens type B in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Chuwen Lin

    2016-03-01

    Full Text Available The detoxified beta1–epsilon (β1–ϵ toxin protein of Clostridium perfringens type B provides protection from C. perfringens types B, C and D infections. Acetate is the primary by-product from the cell growth and expression of β1–ϵ protein. In the present study, the effects of pH and dissolved oxygen (DO on the expression of β1--ϵ protein were investigated. Two-stage pH and DO control strategies were developed for the expression of β1–ϵ protein. The obtained results indicated that higher cell density and concentration of β1--ϵ protein, and lower accumulation of acetate were obtained when pH was maintained at a constant level of 6.5 (0–6 h and 7.0 (6–16 h, and the DO level was maintained at 60% (0–6 h and 30% (6–16 h. Furthermore, the impact of intermittent, DO feedback, pH feedback and glucose-stat feeding on the expression of β1–ϵ protein were studied. By using the DO feedback feeding, combined with the stage control of pH (6.5 for 0–6 h, 7.0 for 6–16 h and DO (60% for 0–6 h, 30% for 6–16 h, the highest cell density of 2.045 (absorbance at 600 nm and a β1–ϵ protein concentration of 63.24 mg/L were obtained, and the accumulation of acetate decreased to 0.872 g/L.

  5. Detection of target staphylococcal enterotoxin B antigen in orange juice and popular carbonated beverages using antibody-dependent antigen-capture assays.

    Science.gov (United States)

    Principato, MaryAnn; Njoroge, Joyce M; Perlloni, Andrei; O' Donnell, Michael; Boyle, Thomas; Jones, Robert L

    2010-10-01

    There is a critical need for qualitative and quantitative methodologies that provide the rapid and accurate detection of food contaminants in complex food matrices. However, the sensitivity of the assay can be affected when antigen-capture is applied to certain foods or beverages that are extremely acidic. This study was undertaken to assess the effects of orange juice and popular carbonated soft drink upon the fidelity of antibody-based antigen-capture assays and to develop simple approaches that could rescue assay performance without the introduction of additional or extensive extraction procedures. We examined the effects of orange juice and a variety of popular carbonated soft drink beverages upon a quantitative Interleukin-2 (IL-2) enzyme-linked immunosorbent assay (ELISA) assay system and a lateral flow device (LFD) adapted for the detection of staphylococcal enterotoxin B (SEB) in foods. Alterations in the performance and sensitivity of the assay were directly attributable to the food matrix, and alterations in pH were especially critical. The results demonstrate that approaches such as an alteration of pH and the use of milk as a blocking agent, either singly or in combination, will partially rescue ELISA performance. The same approaches permit lateral flow to efficiently detect antigen. Practical Application: The authors present ways to rescue an ELISA assay compromised by acidity in beverages and show that either the alteration of pH, or the use of milk as a blocking agent are not always capable of restoring the assay to its intended efficiency. However, the same methods, when employed with lateral flow technology, are rapid and extremely successful.

  6. The immunogenic SigA enterotoxin of Shigella flexneri 2a binds to HEp-2 cells and induces fodrin redistribution in intoxicated epithelial cells.

    Directory of Open Access Journals (Sweden)

    Keith Al-Hasani

    Full Text Available BACKGROUND: We have previously shown that the enterotoxin SigA which resides on the she pathogenicity island (PAI of S. flexneri 2a is an autonomously secreted serine protease capable of degrading casein. We have also demonstrated that SigA is cytopathic for HEp-2 cells and plays a role in the intestinal fluid accumulation associated with S. flexneri infections. METHODS/PRINCIPAL FINDINGS: In this work we show that SigA binds specifically to HEp-2 cells and degrades recombinant human alphaII spectrin (alpha-fodrin in vitro, suggesting that the cytotoxic and enterotoxic effects mediated by SigA are likely associated with the degradation of epithelial fodrin. Consistent with our data, this study also demonstrates that SigA cleaves intracellular fodrin in situ, causing its redistribution within cells. These results strongly implicate SigA in altering the cytoskeleton during the pathogenesis of shigellosis. On the basis of these findings, cleavage of fodrin is a novel mechanism of cellular intoxication for a Shigella toxin. Furthermore, information regarding immunogenicity to SigA in infected patients is lacking. We studied the immune response of SigA from day 28 post-challenge serum of one volunteer from S. flexneri 2a challenge studies. Our results demonstrate that SigA is immunogenic following infection with S. flexneri 2a. CONCLUSIONS: This work shows that SigA binds to epithelial HEp-2 cells as well as being able to induce fodrin degradation in vitro and in situ, further extending its documented role in the pathogenesis of Shigella infections.

  7. [Escherichia coli heat-labile enterotoxin B subunit enhances the immune response against canine parvovirus VP2 in mice immunized by VP2 DNA vaccine].

    Science.gov (United States)

    Han, Dongmei; Zhong, Fei; Li, Xiujin; Wang, Wei; Wang, Xingxing; Pan, Sumin

    2011-01-01

    To investigate the effect of Escherichia coli heat-labile enterotoxin (LT) B subunit (LTB) gene on canine parvovirus (CPV) VP2 gene vaccine. The LTB gene was amplified by PCR from genomic DNA of E. coli 44815 strain. The VP2-70 fragment (210 bp) encoding major epitope of VP2 (70 amino acids) was amplified by PCR from a plasmid encoding VP2 gene. VP2-70 and LTB genes were inserted into the eukaryotic vector to construct VP2-70 gene,LTB gene and VP2-70-LTB fused gene vectors. The mice were immunized with VP2-70 vector, VP2-70-LTB fused vector, or VP2-70 vector plus LTB vector, respectively. The antibody titers at the different time were measured by using ELISA method. The spleen lymphocyte proliferation activity was analyzed by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The sequence of VP2-70 and LTB genes was identified. The recombinant VP2-70 and LTB proteins could be expressed in HEK293T cells in a secretory manner. The mice immunized with VP2-70 vector, VP2-70-LTB vector or VP2-70 vector plus LTB vector could generate the specific antibody against VP2 protein. The antibody titer immunized with VP2-70-LTB vector reached 1:5120 at 35 d post immunization, significantly higher than that of other two groups (P vaccine in mice.

  8. Staphylococcal enterotoxin-like X (SElX is a unique superantigen with functional features of two major families of staphylococcal virulence factors.

    Directory of Open Access Journals (Sweden)

    Ries J Langley

    2017-09-01

    Full Text Available Staphylococcus aureus is an opportunistic pathogen that produces many virulence factors. Two major families of which are the staphylococcal superantigens (SAgs and the Staphylococcal Superantigen-Like (SSL exoproteins. The former are immunomodulatory toxins that induce a Vβ-specific activation of T cells, while the latter are immune evasion molecules that interfere with a wide range of innate immune defences. The superantigenic properties of Staphylococcal enterotoxin-like X (SElX have recently been established. We now reveal that SElX also possesses functional characteristics of the SSLs. A region of SElX displays high homology to the sialyl-lactosamine (sLacNac-specific binding site present in a sub-family of SSLs. By analysing the interaction of SElX with sLacNac-containing glycans we show that SElX has an equivalent specificity and host cell binding range to the SSLs. Mutation of key amino acids in this conserved region affects the ability of SElX to bind to cells of myeloid origin and significantly reduces its ability to protect S. aureus from destruction in a whole blood killing (WBK assay. Like the SSLs, SElX is up-regulated early during infection and is under the control of the S. aureus exotoxin expression (Sae two component gene regulatory system. Additionally, the structure of SElX in complex with the sLacNac-containing tetrasaccharide sialyl Lewis X (sLeX reveals that SElX is a unique single-domain SAg. In summary, SElX is an 'SSL-like' SAg.

  9. Isolation of a new ssDNA aptamer against staphylococcal enterotoxin B based on CNBr-activated sepharose-4B affinity chromatography.

    Science.gov (United States)

    Hedayati Ch, Mojtaba; Amani, Jafar; Sedighian, Hamid; Amin, Mohsen; Salimian, Jafar; Halabian, Raheleh; Imani Fooladi, Abbas Ali

    2016-09-01

    Staphylococcus aureus are potent human pathogens possessing arsenal of virulence factors. Staphylococcal food poisoning (SFP) and respiratory infections mediated by staphylococcal enterotoxin B (SEB) are common clinical manifestations. Many diagnostic techniques are based on serological detection and quantification of SEB in different food and clinical samples. Aptamers are known as new therapeutic and detection tools which are available in different ssDNA, dsDNA and protein structures. In this study, we used a new set of ssDNA aptamers against SEB. The methods used included preparation of a dsDNA library using standard SEB protein as the target analyte, affinity chromatography matrix in microfuge tubes, SELEX procedures to isolate specific ssDNA-aptamer as an affinity ligand, aptamer purification using ethanol precipitation method, affinity binding assay using ELISA, aptamer cloning and specificity test. Among 12 readable sequences, three of them were selected as the most appropriate aptamer because of their affinity and specificity to SEB. This study presents a new set of ssDNA aptamer with favorable selectivity to SEB through 12 rounds of SELEX. Selected aptamers were used to detect SEB in infected serum samples. Results showed that SEB c1 aptamer (2 µg SEB/100 nM aptamer) had favorable specificity to SEB (kd  = 2.3 × 10(-11) ). In conclusion, aptamers can be considered as useful tools for detecting and evaluating SEB. The results showed that affinity chromatography was an affordable assay with acceptable accuracy to isolate sensitive and selective novel aptamers. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Immunogenicity of recombinant Lactobacillus casei-expressing F4 (K88) fimbrial adhesin FaeG in conjunction with a heat-labile enterotoxin A (LTAK63) and heat-labile enterotoxin B (LTB) of enterotoxigenic Escherichia coli as an oral adjuvant in mice.

    Science.gov (United States)

    Yu, M; Qi, R; Chen, C; Yin, J; Ma, S; Shi, W; Wu, Y; Ge, J; Jiang, Y; Tang, L; Xu, Y; Li, Y

    2017-02-01

    The aims of this study were to develop an effective oral vaccine against enterotoxigenic Escherichia coli (ETEC) infection and to design new and more versatile mucosal adjuvants. Genetically engineered Lactobacillus casei strains expressing F4 (K88) fimbrial adhesin FaeG (rLpPG-2-FaeG) and either co-expressing heat-labile enterotoxin A (LTA) subunit with an amino acid mutation associated with reduced virulence (LTAK63) and a heat-labile enterotoxin B (LTB) subunit of E. coli (rLpPG-2-LTAK63-co-LTB) or fused-expressing LTAK63 and LTB (rLpPG-2-LTAK63-fu-LTB) were constructed. The immunogenicity of rLpPG-2-FaeG in conjunction with rLpPG-2-LTAK63-co-LTB or rLpPG-2-LTAK63-fu-LTB as an orally administered mucosal adjuvant in mice was evaluated. Results showed that the levels of FaeG-specific serum IgG and mucosal sIgA, as well as the proliferation of lymphocytes, were significantly higher in mice orally co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-fu-LTB compared with those administered rLpPG-2-FaeG alone, and were lower than those co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-co-LTB. Moreover, effective protection was observed after challenge with F4+ ETEC strain CVCC 230 in mice co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-co-LTB or rLpPG-2-FaeG and rLpPG-2-LTAK63-fu-LTB group compared with those that received rLpPG-2-FaeG alone. rLpPG-2-FaeG showed greater immunogenicity in combination with LTAK63 and LTB as molecular adjuvants. Recombinant Lactobacillus provides a promising platform for the development of vaccines against F4+ ETEC infection. © 2016 The Society for Applied Microbiology.

  11. Growth of non-toxigenic Clostridium botulinum mutant LNT01 in cooked beef: One-step kinetic analysis and comparison with C. sporogenes and C. perfringens.

    Science.gov (United States)

    Huang, Lihan

    2018-05-01

    The objective of this study was to investigate the growth kinetics of Clostridium botulinum LNT01, a non-toxigenic mutant of C. botulinum 62A, in cooked ground beef. The spores of C. botulinum LNT01 were inoculated to ground beef and incubated anaerobically under different temperature conditions to observe growth and develop growth curves. A one-step kinetic analysis method was used to analyze the growth curves simultaneously to minimize the global residual error. The data analysis was performed using the USDA IPMP-Global Fit, with the Huang model as the primary model and the cardinal parameters model as the secondary model. The results of data analysis showed that the minimum, optimum, and maximum growth temperatures of this mutant are 11.5, 36.4, and 44.3 °C, and the estimated optimum specific growth rate is 0.633 ln CFU/g per h, or 0.275 log CFU/g per h. The maximum cell density is 7.84 log CFU/g. The models and kinetic parameters were validated using additional isothermal and dynamic growth curves. The resulting residual errors of validation followed a Laplace distribution, with about 60% of the residual errors within ±0.5 log CFU/g of experimental observations, suggesting that the models could predict the growth of C. botulinum LNT01 in ground beef with reasonable accuracy. Comparing with C. perfringens, C. botulinum LNT01 grows at much slower rates and with much longer lag times. Its growth kinetics is also very similar to C. sporogenes in ground beef. The results of computer simulation using kinetic models showed that, while prolific growth of C. perfringens may occur in ground beef during cooling, no growth of C. botulinum LNT01 or C. sporogenes would occur under the same cooling conditions. The models developed in this study may be used for prediction of the growth and risk assessments of proteolytic C. botulinum in cooked meats. Published by Elsevier Ltd.

  12. Padronização da titulação da toxina épsilon de Clostridium perfringens tipo D em linhagem contínua de células como alternativa ao bioensaio animal Standardization of the titration of the epsilon toxin of Clostridium perfringens type D in cell line as an alternative to animal bioassay

    Directory of Open Access Journals (Sweden)

    Milton Formiga Souza Júnior

    2010-03-01

    Full Text Available Enterotoxemia, também chamada de doença do rim pulposo, doença que acomete os ruminantes domésticos, é causada pela ação da toxina épsilon produzida pelo Clostridium perfringens tipo D, um anaeróbio comumente isolado do solo e das fezes de animais sadios. O método tradicional de diagnóstico baseia-se na detecção e classificação dessa exotoxina no conteúdo intestinal por meio da soroneutralização em camundongos. Com isso, o objetivo deste estudo foi padronizar um teste para detecção e titulação dessa toxina in vitro e compará-lo ao fenômeno in vivo. Para isso, uma partida de toxina épsilon de Clostridium perfringens tipo D foi titulada em camundongos e em várias linhagens contínuas de células. Após a determinação da linhagem celular mais sensível, realizaram-se ensaios de titulação in vitro de diluições de uma partida de toxina, comparando-os com os títulos in vivo conhecidos. Os resultados foram agrupados, e foi desenvolvida a equação matemática que melhor adaptou-se aos intervalos trabalhados. A linhagem MDCK, além de mais sensível, demonstrou que o fenômeno observado in vitro pode ser expresso por meio da equação matemática que apresenta uma correlação de 98,33%, com a dose mínima mortal determinada in vivo. Portanto, a linhagem MDCK permite titular a toxina épsilon de C. perfringens tipo D de forma específica e sensível, além de ser uma técnica prática, rápida e que dispensa o uso de animais.Enterotoxemia (also called pulpy kidney disease is an enteric disease, that affect ruminants, produced by epsilon toxin from Clostridium perfringens type D, an anaerobic commonly isolated from soil and feces of healthy animals. The diagnostic is based on detection of this exotoxin in the intestinal content by soroneutralization in mice. Therefore, this study aimed to standardize a test for detection and titration of the toxin in vitro, and compare it with the phenomenon in vivo. A volume of epsilon

  13. Functional insight into the C-terminal extension of halolysin SptA from haloarchaeon Natrinema sp. J7.

    Directory of Open Access Journals (Sweden)

    Zhisheng Xu

    Full Text Available Halolysin SptA from haloarchaeon Natrinema sp. J7 consists of a subtilisin-like catalytic domain and a C-terminal extension (CTE containing two cysteine residues. In this report, we have investigated the function of the CTE using recombinant enzymes expressed in Haloferax volcanii WFD11. Deletion of the CTE greatly reduced but did not abolish protease activity, which suggests that the CTE is not essential for enzyme folding. Mutational analysis suggests that residues Cys303 and Cys338 within the CTE form a disulfide bond that make this domain resistant to autocleavage and proteolysis under hypotonic conditions. Characterization of full-length and CTE-truncation enzymes indicates the CTE not only confers extra stability to the enzyme but also assists enzyme activity on protein substrates by facilitating binding at high salinities. Interestingly, homology modeling of the CTE yields a β-jelly roll-like structure similar to those seen in Claudin-binding domain of Clostridium perfringens enterotoxin (clostridial C-CPE and collagen binding domain (CBD, and the CTE also possesses collagen-binding activity, making it a potential candidate as an anchoring unit in drug delivery systems.

  14. Up-regulation of granzyme B and perforin by staphylococcal enterotoxin C2 mutant induces enhanced cytotoxicity in Hepa1–6 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guojun [Institute of Applied Ecology, Chinese Academy of Sciences, No.72 Wenhua Road Shenhe Dis., Shenyang, Liaoning (China); University of Chinese Academy of Sciences, Beijing (China); Xu, Mingkai, E-mail: mkxu@iae.ac.cn [Institute of Applied Ecology, Chinese Academy of Sciences, No.72 Wenhua Road Shenhe Dis., Shenyang, Liaoning (China); Zhang, Huiwen [Institute of Applied Ecology, Chinese Academy of Sciences, No.72 Wenhua Road Shenhe Dis., Shenyang, Liaoning (China); Song, Yubo [Institute of Applied Ecology, Chinese Academy of Sciences, No.72 Wenhua Road Shenhe Dis., Shenyang, Liaoning (China); University of Chinese Academy of Sciences, Beijing (China); Wang, Jian; Zhang, Chenggang [Institute of Applied Ecology, Chinese Academy of Sciences, No.72 Wenhua Road Shenhe Dis., Shenyang, Liaoning (China)

    2016-12-15

    Staphylococcal enterotoxin C2 (SEC2), a member of bacterial superantigen, is one of the most potent known activators of T lymphocytes. With this property, SEC2 has already been used in clinic as a tumor immunotherapy agent in China. To increase the antitumor activity, a SEC2 mutant named ST-4 (GKVTG102-106WWH) with amino acid substitutions in T cell receptor (TCR)-binding domain was generated by site-directed mutagenesis, and the molecular mechanism of the enhanced antitumor activity was investigated. Results showed that ST-4 could activate much more Vβ 8.2 and 8.3 T cells and NK cells compared with SEC2, and exhibited significantly enhanced immunocyte stimulation and antitumor activity in vitro. The synthetic peptide sequencing the residues of mutant TCR-binding domain could competitively inhibit the immunocyte stimulation activity of ST-4. Most importantly, ST-4 up-regulated granzyme B and perforin at both mRNA and protein levels. We also found that expression of proapoptotic proteins cytochrome c, BAX and activation of caspase-3, 9 was up-regulated, and antiapoptotic protein Bcl-xL was down-regulated in the treatment with either ST-4 or SEC2. When granzyme B inhibitor or perforin inhibitor is presented, tumor cell viability was significantly rescued. Taken together, we demonstrate that increased ST-4-TCR recognition contributed to massive T cells and NK cells activation. These activated cells released up-regulated granzyme B and perforin, which induced the enhanced tumor cells apoptosis by mitochondrial apoptotic pathway, and ultimately led to enhanced tumor cell growth inhibition. ST-4 may be a promising candidate for antitumor clinic usage in future. - Highlights: • We obtained a SEC2 mutant ST-4 with enhanced superantigen and antitumor activity. • Increased ST-4-TCR recognition contributed to massive T cells and NK cells activation. • Up-regulated GzmB and PRF1 in T cell by ST-4 induced enhanced tumor cells apoptosis. • Enhanced tumor cell apoptosis

  15. Natural indoles, indole-3-carbinol and 3,3′-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression

    International Nuclear Information System (INIS)

    Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S.

    2014-01-01

    Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3′-diindolylmethane (DIM), found in cruciferous vegetables, to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8 + T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors. - Highlights: • I3C and DIM reduce SEB-induced T cell activation and inflammatory cytokines. • Inhibiting class I HDACs reduces T cell activation and inflammatory cytokines. • Inhibiting class II HDACs increases T cell activation and inflammatory cytokines. • I3C and DIM selectively reduce mRNA expression of class I HDACs. • Novel use and mechanism to counteract SEB

  16. Natural indoles, indole-3-carbinol and 3,3′-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression

    Energy Technology Data Exchange (ETDEWEB)

    Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S., E-mail: prakash@mailbox.sc.edu

    2014-01-01

    Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3′-diindolylmethane (DIM), found in cruciferous vegetables, to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8{sup +} T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors. - Highlights: • I3C and DIM reduce SEB-induced T cell activation and inflammatory cytokines. • Inhibiting class I HDACs reduces T cell activation and inflammatory cytokines. • Inhibiting class II HDACs increases T cell activation and inflammatory cytokines. • I3C and DIM selectively reduce mRNA expression of class I HDACs. • Novel use and mechanism to counteract

  17. Staphylococcal Entertotoxins of the Enterotoxin Gene Cluster (egcSEs Induce Nitrous Oxide- and Cytokine Dependent Tumor Cell Apoptosis in a Broad Panel of Human Tumor Cells

    Directory of Open Access Journals (Sweden)

    David eTerman

    2013-08-01

    Full Text Available The egcSEs comprise five genetically linked staphylococcal enterotoxins, SEG, SEI, SElM, SElN and SElO and two pseudotoxins which constitute an operon present in up to 80% of Staphylococcus aureus isolates. A preparation containing theses proteins was recently used to treat advanced lung cancer with pleural effusion. We investigated the hypothesis that egcSEs induce nitrous oxide (NO and associated cytokine production and that these agents may be involved in tumoricidal effects against a broad panel of clinically relevant human tumor cells. Preliminary studies showed that egcSEs and SEA activated T cells (range: 11-25% in a concentration dependent manner. Peripheral blood mononuclear cells (PBMCs stimulated with equimolar quantities of egcSEs expressed NO synthase and generated robust levels of nitrite (range: 200-250 µM, a breakdown product of NO; this reaction was inhibited by NG-monomethyl-L-arginine (L-NMMA (0.3 mM, an NO synthase antagonist. Cell free supernatants (CSFs of all egcSE-stimulated PBMCs were also equally effective in inducing concentration dependent tumor cell apoptosis in a broad panel of human tumor cells. The latter effect was due in part to the generation of NO and TNF-α since it was significantly abolished by L-NMMA, anti-TNF-α antibodies respectively and a combination thereof. A hierarchy of tumor cell sensitivity to these CFSs was as follows: lung carcinoma>osteogenic sarcoma>melanoma>breast carcinoma>neuroblastoma. Notably, SEG induced robust activation of NO/TNFα-dependent tumor cell apoptosis comparable to the other egcSEs and SEA despite TNF-α and IFN-γ levels that were 2 and 8 fold lower respectively than the other egcSEs and SEA. Thus, egcSEs produced by S. aureus induce NO synthase and the increased NO formation together with TNF-α appear to contribute to egcSE-mediated apoptosis against a broad panel of human tumor cells.

  18. Incorporation of membrane-anchored flagellin or Escherichia coli heat-labile enterotoxin B subunit enhances the immunogenicity of rabies virus-like particles in mice and dogs

    Directory of Open Access Journals (Sweden)

    Yinglin eQi

    2015-03-01

    Full Text Available Rabies remains an important worldwide public health threat, so safe, effective and affordable vaccines are still being sought. Virus-like particle (VLP-based vaccines targeting various viral pathogens have been successfully produced, licensed and commercialized. Here, we designed and constructed two chimeric rabies virus-like particles (cRVLPs containing rabies virus (RABV glycoprotein (G, matrix (M protein, and membrane-anchored flagellin (EVLP-F or Escherichia coli heat-labile enterotoxin B subunit (EVLP-L as molecular adjuvants to enhance the immune response against rabies. The immunogenicity and potential of cRVLPs as novel rabies vaccine were evaluated by intramuscular vaccination in mouse and dog models. Mouse studies demonstrated that both EVLP-F and EVLP-L induced faster and larger virus-neutralizing antibodies (VNA responses and elicited greater numbers of CD4+ and CD8+ T cells secreting IFN-γ or IL-4 compared with a standard rabies VLP (sRVLP containing only G and M. Moreover, cRVLPs recruited and/or activated more B cells and dendritic cells in inguinal lymph nodes. EVLP-F induced a strong, specific IgG2a response but not an IgG1 response, suggesting the activation of Th1 class immunity; in contrast, Th2 class immunity was observed with EVLP-L. The significantly enhanced humoral and cellular immune responses induced by cRVLPs provided complete protection against lethal challenge with RABV. Most importantly, dogs vaccinated with EVLP-F or EVLP-L exhibited increased VNA titers in sera and enhanced IFN-γ and IL-4 secretion from peripheral blood mononuclear cells. Taken together, these results illustrate that when incorporated into sRVLP, membrane-anchored flagellin and LTB possess strong adjuvant activity. EVLP-F and EVLP-L induce significantly enhanced RABV-specific humoral and cellular immune responses in both mouse and dog. Therefore, these cRVLPs may be developed as safe and more efficacious rabies vaccine candidate for animals.

  19. Claudin-4-targeted optical imaging detects pancreatic cancer and its precursor lesions.

    Science.gov (United States)

    Neesse, Albrecht; Hahnenkamp, Anke; Griesmann, Heidi; Buchholz, Malte; Hahn, Stefan A; Maghnouj, Abdelouahid; Fendrich, Volker; Ring, Janine; Sipos, Bence; Tuveson, David A; Bremer, Christoph; Gress, Thomas M; Michl, Patrick

    2013-07-01

    Novel imaging methods based on specific molecular targets to detect both established neoplasms and their precursor lesions are highly desirable in cancer medicine. Previously, we identified claudin-4, an integral constituent of tight junctions, as highly expressed in various gastrointestinal tumours including pancreatic cancer. Here, we investigate the potential of targeting claudin-4 with a naturally occurring ligand to visualise pancreatic cancer and its precursor lesions in vitro and in vivo by near-infrared imaging approaches. A non-toxic C-terminal fragment of the claudin-4 ligand Clostridium perfringens enterotoxin (C-CPE) was labelled with a cyanine dye (Cy5.5). Binding of the optical tracer was analysed on claudin-4 positive and negative cells in vitro, and tumour xenografts in vivo. In addition, two genetically engineered mouse models for pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer were used for in vivo validation. Optical imaging studies were conducted using 2D planar fluorescence reflectance imaging (FRI) technology and 3D fluorescence-mediated tomography (FMT). In vitro, the peptide-dye conjugate showed high binding affinity to claudin-4 positive CAPAN1 cells, while claudin-4 negative HT1080 cells revealed little or no fluorescence. In vivo, claudin-4 positive tumour xenografts, endogenous pancreatic tumours, hepatic metastases, as well as preinvasive PanIN lesions, were visualised by FRI and FMT up to 48 h after injection showing a significantly higher average of fluorochrome concentration as compared with claudin-4 negative xenografts and normal pancreatic tissue. C-CPE-Cy5.5 combined with novel optical imaging methods enables non-invasive visualisation of claudin-4 positive murine pancreatic tumours and their precursor lesions, representing a promising modality for early diagnostic imaging.

  20. Release of Glycoprotein (GP1 from the Tegumental Surface of Taenia solium by Phospholipase C from Clostridium perfringens Suggests a Novel Protein-Anchor to Membranes

    Directory of Open Access Journals (Sweden)

    Abraham Landa

    2010-01-01

    Full Text Available In order to explore how molecules are linked to the membrane surface in larval Taenia solium, whole cysticerci were incubated in the presence of phospholipase C from Clostridium perfringens (PLC. Released material was collected and analyzed in polyacrylamide gels with sodium dodecyl sulfate. Two major bands with apparent molecular weights of 180 and 43 kDa were observed. Western blot of released material and localization assays in cysticerci tissue sections using antibodies against five known surface glycoproteins of T. solium cysticerci indicated that only one, previously called GP1, was released. Similar localization studies using the lectins wheat-germ-agglutinin and Concanavalin A showed that N-acetyl-D-glucosamine, N-acetylneuraminic, sialic acid, αmethyl-D-mannoside, D-manose/glucose, and N-acetyl-D-glucosamine residues are abundantly present on the surface. On the other hand, we find that treatment with PLC releases molecules from the surface; they do not reveal Cross Reacting Determinant (CRD, suggesting a novel anchor to the membrane for the glycoprotein GP1.

  1. Phospholipase C produced by Clostridium botulinum types C and D: comparison of gene, enzymatic, and biological activities with those of Clostridium perfringens alpha-toxin.

    Science.gov (United States)

    Fatmawati, Ni Nengah Dwi; Sakaguchi, Yoshihiko; Suzuki, Tomonori; Oda, Masataka; Shimizu, Kenta; Yamamoto, Yumiko; Sakurai, Jun; Matsushita, Osamu; Oguma, Keiji

    2013-01-01

    Clostridium botulinum type C and D strains recently have been found to produce PLC on egg yolk agar plates. To characterize the gene, enzymatic and biological activities of C. botulinum PLCs (Cb-PLCs), the cb-plc genes from 8 strains were sequenced, and 1 representative gene was cloned and expressed as a recombinant protein. The enzymatic and hemolytic activities of the recombinant Cb-PLC were measured and compared with those of the Clostridium perfringens alpha-toxin. Each of the eight cb-plc genes encoded a 399 amino acid residue protein preceded by a 27 residue signal peptide. The protein consists of 2 domains, the N- and C-domains, and the overall amino acid sequence identity between Cb-PLC and alpha-toxin was greater than 50%, suggesting that Cb-PLC is homologous to the alpha-toxin. The key residues in the N-domain were conserved, whereas those in the C-domain which are important in membrane interaction were different than in the alpha-toxin. As expected, Cb-PLC could hydrolyze egg yolk phospholipid, p-nitrophenylphosphorylcholine, and sphingomyelin, and also exhibited hemolytic activity;however, its activities were about 4- to over 200-fold lower than those of alpha-toxin. Although Cb-PLC showed weak enzymatic and biological activities, it is speculated that Cb-PLC might play a role in the pathogenicity of botulism or for bacterial survival.

  2. 1H, 15N and 13C backbone and side-chain resonance assignments of a family 32 carbohydrate-binding module from the Clostridium perfringens NagH.

    Science.gov (United States)

    Grondin, Julie M; Chitayat, Seth; Ficko-Blean, Elizabeth; Boraston, Alisdair B; Smith, Steven P

    2012-10-01

    The Gram-positive anaerobe Clostridium perfringens is an opportunistic bacterial pathogen that secretes a battery of enzymes involved in glycan degradation. These glycoside hydrolases are thought to be involved in turnover of mucosal layer glycans, and in the spread of major toxins commonly associated with the development of gastrointestinal diseases and gas gangrene in humans. These enzymes employ multi-modularity and carbohydrate-binding function to degrade extracellular eukaryotic host sugars. Here, we report the full (1)H, (15)N and (13)C chemical shift resonance assignments of the first family 32 carbohydrate-binding module from NagH, a secreted family 84 glycoside hydrolase.

  3. Challenging the roles of CD44 and lipolysis stimulated lipoprotein receptor in conveying Clostridium perfringens iota toxin cytotoxicity in breast cancer.

    Science.gov (United States)

    Fagan-Solis, Katerina D; Reaves, Denise K; Rangel, M Cristina; Popoff, Michel R; Stiles, Bradley G; Fleming, Jodie M

    2014-07-02

    Translational exploration of bacterial toxins has come to the forefront of research given their potential as a chemotherapeutic tool. Studies in select tissues have demonstrated that Clostridium perfringens iota toxin binds to CD44 and lipolysis stimulated lipoprotein receptor (LSR) cell-surface proteins. We recently demonstrated that LSR expression correlates with estrogen receptor positive breast cancers and that LSR signaling directs aggressive, tumor-initiating cell behaviors. Herein, we identify the mechanisms of iota toxin cytotoxicity in a tissue-specific, breast cancer model with the ultimate goal of laying the foundation for using iota toxin as a targeted breast cancer therapy. In vitro model systems were used to determine the cytotoxic effect of iota toxin on breast cancer intrinsic subtypes. The use of overexpression and knockdown technologies confirmed the roles of LSR and CD44 in regulating iota toxin endocytosis and induction of cell death. Lastly, cytotoxicity assays were used to demonstrate the effect of iota toxin on a validated set of tamoxifen resistant breast cancer cell lines. Treatment of 14 breast cancer cell lines revealed that LSR+/CD44- lines were highly sensitive, LSR+/CD44+ lines were slightly sensitive, and LSR-/CD44+ lines were resistant to iota cytotoxicity. Reduction in LSR expression resulted in a significant decrease in toxin sensitivity; however, overexpression of CD44 conveyed toxin resistance. CD44 overexpression was correlated with decreased toxin-stimulated lysosome formation and decreased cytosolic levels of iota toxin. These findings indicated that expression of CD44 drives iota toxin resistance through inhibition of endocytosis in breast cancer cells, a role not previously defined for CD44. Moreover, tamoxifen-resistant breast cancer cells exhibited robust expression of LSR and were highly sensitive to iota-induced cytotoxicity. Collectively, these data are the first to show that iota toxin has the potential to be an

  4. Avaliação da capacidade probiótica de uma linhagem de Ruminococcus gnavus da microbiota fecal de seres humanos contra Clostridium perfringens

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Ferreira Barbosa

    2011-03-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 Probióticos são microrganismos utilizados com o propósito de beneficiar a saúde do hospedeiro, seja na prevenção ou tratamento de doenças. Este trabalho teve como objetivo avaliar uma cultura de Ruminococcus gnavus quanto ao seu efeito probiótico frente a um alvo patogênico in vivo por meio de avaliação histopatológica e perfil de hidrofobicidade da parede celular. A linhagem de R. gnavus foi isolada da microbiota fecal dominante de um adulto sadio. Uma amostra padrão de Clostridium perfringens foi utilizada como patógeno para o desafio por via oral de camundongos previamente monoassociados com R. gnavus. Camundongos suíços NIH isentos de germes foram usados como modelo animal. Nos resultados dos testes de adesão da superfície celular do microrganismo estudado, ficou constatado que a espécie R. gnavus possui uma parede celular mais hidrofóbica e ácida, sinalizando boa probabilidade de adesão ao epitélio intestinal. A análise histológica demonstrou que a monoassociação com R. gnavus não promoveu nenhuma alteração morfológica dos órgãos analisados (intestinos, baço e fígado, e apresentou efeito protetor, constatado no ceco e no fígado de camundongos gnotobióticos. Em suma, os resultados reforçam que R. gnavus possui características protetoras desejáveis no que tange a elaboração de futuros probióticos.

  5. Systemic Vulnerabilities in Customer-Premises Equipment (CPE) Routers

    Science.gov (United States)

    2017-07-01

    www.sei.cmu.edu CMU/SEI-2017-SR-019 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY [Distribution Statement A: This material has been...approved for public release and unlimited distribution.] Copyright 2017 Carnegie Mellon University. All Rights Reserved. This material is based...upon work funded and supported by the Department of Defense under Contract No. FA8702-15-D-0002 with Carnegie Mellon University for the operation of

  6. The effect of Artemisia annua on broiler performance, on intestinal microbiota and on the course of a Clostridium perfringens infection applying a necrotic enteritis disease model

    DEFF Research Database (Denmark)

    Engberg, Ricarda M; Grevsen, Kai; Ivarsen, Elise

    2012-01-01

    The aerial parts of the plant Artemisia annua contain essential oils having antimicrobial properties against Clostridium perfringens Type A, the causal agent for necrotic enteritis in broilers. In two experiments, the influence of increasing dietary concentrations of dried A. annua leaves (0, 5, 10...... and 20 g/kg) and n-hexane extract from fresh A. annua leaves (0, 125, 250 and 500 mg/kg) on broiler performance was investigated. Dried plant material decreased feed intake and body weight in a dose-dependent manner, and 10 and 20 g/kg diet tended to improve the feed conversion ratio. The n...... the effect of the dietary addition of dried A. annua leaves (10 g/kg on top) or n-hexane extract of A. annua (250 mg/kg) on the severity of the disease in broilers. The addition of n-hexane extract reduced the intestinal C. perfringens numbers and the severity of the disease-related small intestinal lesions...

  7. The influence of headspace and dissolved oxygen level on growth and haemolytic BL enterotoxin production of a psychrotolerant Bacillus weihenstephanensis isolate on potato based ready-to-eat food products.

    Science.gov (United States)

    Samapundo, S; Everaert, H; Wandutu, J N; Rajkovic, A; Uyttendaele, M; Devlieghere, F

    2011-04-01

    The major objective of this study was to determine the influence of the initial headspace and dissolved O(2) level and vacuum packaging on growth and diarrhoeal enterotoxin production by Bacillus weihenstephanensis on potato based ready-to-eat food products. In general, the lower the initial headspace or dissolved O(2) level the slower the maximum growth rate (μ(max), log(10) CFU g(-1) d(-1)), the longer the lag phase duration (λ, d) and the smaller the maximum population density (N(max), log(10) CFU g(-1)) became. The slowest μ(max), the longest λ and the smallest N(max) were generally found for growth under vacuum packaging. This implies shorter shelf-lives will occur at higher initial headspace or dissolved O(2) levels as the growth of B. weihenstephanensis to the infective dose of 10(5) CFU g(-1) in such atmospheres takes a shorter time. Significant consumption of dissolved O(2) only occurred when growth shifted from the lag to the exponential phase and growth generally transitioned from the exponential to the stationary phase when the dissolved O(2) levels fell below ca. 75 ppb. Diarrhoeal enterotoxin production (determined via detection of the L2 component of haemolytic BL) was similar for growth under initial headspace O(2) levels of 1-20.9%, and was only reduced when growth took place under vacuum packaging. The reduction in L2 production when growth took place under vacuum was most probably related to the low final cell densities observed under this condition. Both growth and L2 production were inhibited over a 32-day incubation period at 7 °C by 40% CO(2) irrespective of the headspace or dissolved O(2) levels. The results illustrate the importance of residual O(2) and CO(2) on the shelf-stability and safety of modified atmosphere packaged potato based ready-to-eat food products with regards to B. weihenstephanensis. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Experimental investigation into the effects of irradiation with mixed neutron-gamma-rays on the immune system as demonstrated by the model of immunity to Staphylococcal Enterotoxin B in rabbits

    International Nuclear Information System (INIS)

    Kraus, W.

    1984-01-01

    Using the model of immunisation of rabbits with Staphylococcal Enterotoxin B the influence of neutron radiation on the antibody response was investigated. Four groups were formed, which differed by the moment of irradiation with regard to the moment of immunisation and re-immunisation, and were irradiated with neutron-rays of 200 rad and 300 rad doses. Both doses were each given before and after vaccination, respectively before and after re-vaccination. The antibody response has been evaluated by the Radio-Immuno-Assay (RIA): Neutron-radiation given 24 hours before vaccination effects a stronger immune suppression than given 24 hours after vaccination. By pre-antigenic radiation a secondary immune response is more suppressed than by radiation following the antigen; the recovery of lymphoid tissue, however, takes place in a shorter time than in case of radiation before or after a primary vaccination. The secondary antibody response to a re-vaccination is not influenced by a subsequent neutron-radiation. The formation of secondary antibodies is not as radiosensitive as the formation of primary ones. By a neutron-radiation preformed antibodies are hardly damaged. (orig./MG) [de

  9. Organization and ELISA-Based Results of the First Proficiency Testing to Evaluate the Ability of European Union Laboratories to Detect Staphylococcal Enterotoxin Type B (SEB in Buffer and Milk

    Directory of Open Access Journals (Sweden)

    Yacine Nia

    2016-09-01

    Full Text Available The aim of this work was to organize the first proficiency test (PT dedicated to staphylococcal enterotoxin B (SEB detection in milk and buffer solutions. This paper describes the organization of the PT trial according to EN ISO 17043 requirements. Characterization of the SEB stock solution was performed using SDS-PAGE and SE-specific ELISA, and amino acid analysis was used to assign its protein concentration. The solution was then used to prepare six PT materials (four milk and two buffer batches at a ng/g toxin level, which included one blank and one SEA-containing milk as specificity control. Suitable material homogeneity and stability were assessed using screening and quantitative ELISAs. Among the methods used by the participants, ELISA-based methods demonstrated their efficiency for the detection of SEB in both simple and complex matrices. The results serve as a basis for further improving the detection capabilities in expert laboratories and can therefore be considered as a contribution to biopreparedness.

  10. Bacteroides fragilis Enterotoxin Induces Formation of Autophagosomes in Endothelial Cells but Interferes with Fusion with Lysosomes for Complete Autophagic Flux through a Mitogen-Activated Protein Kinase-, AP-1-, and C/EBP Homologous Protein-Dependent Pathway.

    Science.gov (United States)

    Ko, Su Hyuk; Jeon, Jong Ik; Myung, Hyun Soo; Kim, Young-Jeon; Kim, Jung Mogg

    2017-10-01

    Bacteroides fragilis enterotoxin (BFT), a virulence factor of enterotoxigenic B. fragilis (ETBF), plays an essential role in mucosal inflammation. Although autophagy contributes to the pathogenesis of diverse infectious diseases, little is known about autophagy in ETBF infection. This study was conducted to investigate the role of BFT in the autophagic process in endothelial cells (ECs). Stimulation of human umbilical vein ECs (HUVECs) with BFT increased light chain 3 protein II (LC3-II) conversion from LC3-I and protein expression of p62, Atg5, and Atg12. In addition, BFT-exposed ECs showed increased indices of autophagosomal fusion with lysosomes such as LC3-lysosome-associated protein 2 (LAMP2) colocalization and the percentage of red vesicles monitored by the expression of dual-tagged LC3B. BFT also upregulated expression of C/EBP homologous protein (CHOP), and inhibition of CHOP significantly increased indices of autophagosomal fusion with lysosomes. BFT activated an AP-1 transcription factor, in which suppression of AP-1 activity significantly downregulated CHOP and augmented autophagosomal fusion with lysosomes. Furthermore, suppression of Jun N-terminal protein kinase (JNK) mitogen-activated protein kinase (MAPK) significantly inhibited the AP-1 and CHOP signals, leading to an increase in autophagosomal fusion with lysosomes in BFT-stimulated ECs. These results suggest that BFT induced accumulation of autophagosomes in ECs, but activation of a signaling pathway involving JNK, AP-1, and CHOP may interfere with complete autophagy. Copyright © 2017 American Society for Microbiology.

  11. Comparação entre hipoclorito de sódio e ácido peracético na inativação de E. coli, colifagos e C. perfringens em água com elevada concentração de matéria orgânica Comparison between sodium hipoclorite and peracetic acid for E. coli, coliphages and C. perfringens inactivation of high organic matter concentration water

    Directory of Open Access Journals (Sweden)

    Jeanette Beber de Souza

    2005-06-01

    Full Text Available Foi realizado estudo comparativo em condições experimentais similares, entre hipoclorito de sódio e ácido peracético na desinfecção de água com elevada concentração de matéria orgânica. O conteúdo de carbono orgânico dissolvido (COD variou de 4,652 a 30,13 mgC/L para a água de estudo bruta e após a desinfecção esses valores variaram de 5,105 a 26,16 mgC/L para os ensaios com cloro e de 15,89 a 32,78 mgC/L para os ensaios com ácido peracético. O desempenho dos dois desinfetantes foi avaliado segundo a inativação de três microrganismos indicadores, Escherichia coli ATCC 11229, colifagos e Clostridium perfringens ATCC 13124 que eram previamente cultivados e inoculados à água no momento do experimento. As concentrações aplicadas de cloro e ácido peracético foram de 2,0; 3,0; 4,0 e 5,0 mg/L e os tempos de contato de 5, 10, 15 e 20 minutos. Para 3,0 mg/L de cloro aplicado, obteve-se 3 log de inativação de E. coli em 20 minutos de contato, 2,92 log de inativação de fagos em 10 minutos e 2 log de inativação de C. perfringens em 15 minutos. Os resultados dos ensaios de desinfecção com ácido peracético indicaram efetiva inativação dos microrganismos indicadores empregados, mesmo na presença de elevada concentração de matéria orgânica. Para 5,0 mg/L de ácido peracético aplicado e 15 minutos de contato, inativações de E. coli maiores que 6 log, de fagos maiores que 5 log em 20 minutos e de C. perfringens maiores que 4 log em 10 minutos de contato foram alcançadas.The research comparing the action of sodium hypochlorite and peracetic acid to disinfect drinking water with high concentration organic matter was carried out in similar conditions. The dissolved organic carbon (DOC concentration was from 4.652 to 30.13 mg/L in raw water, from 5.105 to 26.16 mg/L in water disinfected with chlorine and from 15.89 to 32.72 mg/L in water disinfected with peracetic acid. The efficiency of the two disinfectants was

  12. Attenuated Escherichia coli strains expressing the colonization factor antigen I (CFA/I) and a detoxified heat-labile enterotoxin (LThK63) enhance clearance of ETEC from the lungs of mice and protect mice from intestinal ETEC colonization and LT-induced fluid accumulation.

    Science.gov (United States)

    Byrd, Wyatt; Boedeker, Edgar C

    2013-03-15

    Although enterotoxigenic Escherichia coli (ETEC) infections are important causes of infantile and traveler's diarrhea there is no licensed vaccine available for those at-risk. Our goal is to develop a safe, live attenuated ETEC vaccine. We used an attenuated E. coli strain (O157:H7, Δ-intimin, Stx1-neg, Stx2-neg) as a vector (ZCR533) to prepare two vaccine strains, one strain expressing colonization factor antigen I (ZCR533-CFA/I) and one strain expressing CFA/I and a detoxified heat-labile enterotoxin (ZCR533-CFA/I+LThK63) to deliver ETEC antigens to mucosal sites in BALB/c mice. Following intranasal and intragastric immunization with the vaccine strains, serum IgG and IgA antibodies were measured to the CFA/I antigen, however, only serum IgG antibodies were detected to the heat-labile enterotoxin. Intranasal administration of the vaccine strains induced respiratory and intestinal antibody responses to the CFA/I and LT antigens, while intragastric administration induced only intestinal antibody responses with no respiratory antibodies detected to the CFA/I and LT antigens. Mice immunized intranasally with the vaccine strains showed enhanced clearance of wild-type (wt) ETEC bacteria from the lungs. Mice immunized intranasally and intragastrically with the vaccine strains were protected from intestinal colonization following oral challenge with ETEC wt bacteria. Mice immunized intragastrically with the ZCR533-CFA/I+LThK63 vaccine strain had less fluid accumulate in their intestine following challenge with ETEC wt bacteria or with purified LT as compared to the sham mice indicating that the immunized mice were protected from LT-induced intestinal fluid accumulation. Thus, mice intragastrically immunized with the ZCR533-CFA/I+LThK63 vaccine strain were able to effectively neutralize the activity of the LT enterotoxin. However, no difference in intestinal fluid accumulation was detected in the mice immunized intranasally with the vaccine strain as compared to the sham

  13. Produção de enterotoxinas e da toxina da síndrome do choque tóxico por cepas de Staphylococcus aureus isoladas na mastite bovina Production of enterotoxins and toxic shock syndrome toxin by Staphylococcus aureus strains isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    A. Nader Filho

    2007-10-01

    Full Text Available A total of 72 strains of Staphylococcus aureus were examined for the production of staphylococcal enterotoxins (SE A, B, C, D and toxic shock syndrome toxin (TSST-1. The strains were isolated from milk samples from cows with mastitis in dairy herds of São Paulo State, Brazil. Off 72 isolates, 38 (52.8% produced SEA, 38 (52.8% SEB, 32 (44.4% SED, 28 (38.9% SEC and 27 (37.5% TSST-1. From the 72 strains, 66 (91.7% produced, at least, one or more toxin, including TSST-1.

  14. Natural indoles, indole-3-carbinol (I3C and 3,3'-diindolylmethane (DIM, attenuate staphylococcal enterotoxin B-mediated liver injury by downregulating miR-31 expression and promoting caspase-2-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    Philip B Busbee

    Full Text Available Staphylococcal enterotoxin B (SEB is a potent superantigen capable of inducing inflammation characterized by robust immune cell activation and proinflammatory cytokine release. Exposure to SEB can result in food poisoning as well as fatal conditions such as toxic shock syndrome. In the current study, we investigated the effect of natural indoles including indole-3-carbinol (I3C and 3,3'-diindolylmethane (DIM on SEB-mediated liver injury. Injection of SEB into D-galactosamine-sensitized female C57BL/6 mice resulted in liver injury as indicated by an increase in enzyme aspartate transaminase (AST levels, induction of inflammatory cytokines, and massive infiltration of immune cells into the liver. Administration of I3C and DIM (40 mg/kg, by intraperitonal injection, attenuated SEB-induced acute liver injury, as evidenced by decrease in AST levels, inflammatory cytokines and cellular infiltration in the liver. I3C and DIM triggered apoptosis in SEB-activated T cells primarily through activation of the intrinsic mitochondrial pathway. In addition, inhibitor studies involving caspases revealed that I3C and DIM-mediated apoptosis in these activated cells was dependent on caspase-2 but independent of caspase-8, 9 and 3. In addition, I3C and DIM caused a decrease in Bcl-2 expression. Both compounds also down-regulated miR-31, which directly targets caspase-2 and influences apoptosis in SEB-activated cells. Our data demonstrate for the first time that indoles can effectively suppress acute hepatic inflammation caused by SEB and that this may be mediated by decreased expression of miR-31 and consequent caspase-2-dependent apoptosis in T cells.

  15. Influence of Host Interleukin-10 Polymorphisms on Development of Traveler's Diarrhea Due to Heat-Labile Enterotoxin-Producing Escherichia coli in Travelers from the United States Who Are Visiting Mexico▿

    Science.gov (United States)

    Flores, Jose; DuPont, Herbert L.; Lee, Stephanie A.; Belkind-Gerson, Jaime; Paredes, Mercedes; Mohamed, Jamal A.; Armitige, Lisa Y.; Guo, Dong-Chuan; Okhuysen, Pablo C.

    2008-01-01

    Up to 60% of U.S. visitors to Mexico develop traveler's diarrhea (TD), mostly due to enterotoxigenic Escherichia coli (ETEC) strains that produce heat-labile (LT) and/or heat-stable (ST) enterotoxins. Distinct single-nucleotide polymorphisms (SNPs) within the interleukin-10 (IL-10) promoter have been associated with high, intermediate, or low production of IL-10. We conducted a prospective study to investigate the association of SNPs in the IL-10 promoter and the occurrence of TD in ETEC LT-exposed travelers. Sera from U.S. travelers to Mexico collected on arrival and departure were studied for ETEC LT seroconversion by using cholera toxin as the antigen. Pyrosequencing was performed to genotype IL-10 SNPs. Stools from subjects who developed diarrhea were also studied for other enteropathogens. One hundred twenty-one of 569 (21.3%) travelers seroconverted to ETEC LT, and among them 75 (62%) developed diarrhea. Symptomatic seroconversion was more commonly seen in subjects who carried a genotype producing high levels of IL-10; it was seen in 83% of subjects with the GG genotype versus 54% of subjects with the AA genotype at IL-10 gene position −1082 (P, 0.02), in 71% of those with the CC genotype versus 33% of those with the TT genotype at position −819 (P, 0.005), and in 71% of those with the CC genotype versus 38% of those with the AA genotype at position −592 (P, 0.02). Travelers with the GCC haplotype were more likely to have symptomatic seroconversion than those with the ATA haplotype (71% versus 38%; P, 0.002). Travelers genetically predisposed to produce high levels of IL-10 were more likely to experience symptomatic ETEC TD. PMID:18579697

  16. Influence of host interleukin-10 polymorphisms on development of traveler's diarrhea due to heat-labile enterotoxin-producing Escherichia coli in travelers from the United States who are visiting Mexico.

    Science.gov (United States)

    Flores, Jose; DuPont, Herbert L; Lee, Stephanie A; Belkind-Gerson, Jaime; Paredes, Mercedes; Mohamed, Jamal A; Armitige, Lisa Y; Guo, Dong-Chuan; Okhuysen, Pablo C

    2008-08-01

    Up to 60% of U.S. visitors to Mexico develop traveler's diarrhea (TD), mostly due to enterotoxigenic Escherichia coli (ETEC) strains that produce heat-labile (LT) and/or heat-stable (ST) enterotoxins. Distinct single-nucleotide polymorphisms (SNPs) within the interleukin-10 (IL-10) promoter have been associated with high, intermediate, or low production of IL-10. We conducted a prospective study to investigate the association of SNPs in the IL-10 promoter and the occurrence of TD in ETEC LT-exposed travelers. Sera from U.S. travelers to Mexico collected on arrival and departure were studied for ETEC LT seroconversion by using cholera toxin as the antigen. Pyrosequencing was performed to genotype IL-10 SNPs. Stools from subjects who developed diarrhea were also studied for other enteropathogens. One hundred twenty-one of 569 (21.3%) travelers seroconverted to ETEC LT, and among them 75 (62%) developed diarrhea. Symptomatic seroconversion was more commonly seen in subjects who carried a genotype producing high levels of IL-10; it was seen in 83% of subjects with the GG genotype versus 54% of subjects with the AA genotype at IL-10 gene position -1082 (P, 0.02), in 71% of those with the CC genotype versus 33% of those with the TT genotype at position -819 (P, 0.005), and in 71% of those with the CC genotype versus 38% of those with the AA genotype at position -592 (P, 0.02). Travelers with the GCC haplotype were more likely to have symptomatic seroconversion than those with the ATA haplotype (71% versus 38%; P, 0.002). Travelers genetically predisposed to produce high levels of IL-10 were more likely to experience symptomatic ETEC TD.

  17. Perfil de contaminação por Staphylococcus e suas enterotoxinas e monitorização das condições de higiene em uma linha de produção de queijo de coalho Contamination profile for staphylococci and its enterotoxins and monitorization of the conditions of hygiene in a ‘coalho' cheese production line

    Directory of Open Access Journals (Sweden)

    Maria de Fatima Borges

    2008-08-01

    Full Text Available Avaliou-se o perfil de contaminação por Staphylococcus e suas enterotoxinas e monitorou-se as condições de higiene em uma linha de produção de queijo de coalho por meio da técnica de bioluminescência (ATP. A população de Staphylococcus sp. variou de This research aimed to evaluate the contamination by staphylococci and its enterotoxins as well as to monitor the conditions of hygiene from a coalho cheese production line, using ATP bioluminescence assay. Staphylococcus sp. population varied from <1CFU mL-1, in pasteurized milk to 1.5 x 107CFU mL-1, in raw milk, whereas coagulase-positive staphylococci count ranged from <1CFU mL-1, in pasteurized milk to 5.0 x 106CFU mL-1 in raw milk. Coagulase-positive staphylococci were detected in 100% (25/25 of the raw milk samples and in 8% (2/25 of cheese samples. Twelve Staphylococcus species were identified within the selected 68 isolates, being nine negative and three positive for coagulase. Raw milk samples showed a high rate of coagulase-positive, being S. aureus the most common, whereas other product samples and equipment surfaces, pieces of furniture, utensils and manipulator gloves samples presented a high frequency of coagulase-negative and low frequency of coagulase-positive. Staphylococcal enterotoxin was detected in 20% of the raw milk samples and therefore in pasteurized milk, curd and cheese. ATP measurement permitted to assess the effectiveness of the surfaces cleaning, being considered adequate in 62.1% (36/95, "alert state" in 23.2% (22/95 and inadequate in 14.7% (14/95 of surfaces evaluated. Detection of staphylococci species with enterotoxigenic potential as well as enterotoxin presence reveal dissemination of contamination at the "coalho" cheese production line, possibly due inappropriate Good Manufacturing Practices (GMP from the initial milking step until the final cheese production.

  18. Histopathological Changes Induced By Staphylococcal Enterotoxin ...

    African Journals Online (AJOL)

    In this study, six Staphylococcus aureus strains isolated from contaminated yoghurt were evaluated for enterotoxigenicity. Two o the strains were enterotoxigenic and caused fluid accumulation in rabbit ileal loops. Fluid aspirated from the loops was bloody and histopathological changes in sections collected from rabbit ...

  19. A crop production ecology (CPE) approach to sustainable production of biomass for food, feed and fuel

    NARCIS (Netherlands)

    Haverkort, A.J.; Bindraban, P.S.; Conijn, J.G.; Ruijter, de F.J.

    2009-01-01

    With the rapid increase in demand for agricultural products for food, feed and fuel, concerns are growing about sustainability issues. Can agricultural production meet the needs of increasing numbers of people consuming more animal products and using a larger share of crops as fuel for transport,

  20. Incorporation of a Cationic Conjugated Polyelectrolyte CPE within an Aqueous Poly(vinyl alcohol) Sol

    DEFF Research Database (Denmark)

    Knaapila, Matti; Stewart, Beverly; Costa, Telma

    2016-01-01

    We report on a multiscale polymer-within-polymer structure of the cationic conjugated polyelectrolyte poly{[9,9-bis(6-N,N,N-trimethylammonium)hexyl]fluorene phenylene} (HTMAPFP) in aqueous poly(vinyl alcohol).(PVA) sol. Molecular dynamics simulations and small-angle neutron scattering (SANS) data...... show that HTMA-PFP forms aggregates in water but becomes entangled by PVA (with a 1:1 molar ratio of HTMA-PFP to PVA) and eventually immersed in PVA clusters (with the ratio 1:4). This is attributed to the hydrophobic hydrophilic balance. Contrast variation data with regular and deuterated PVA support...

  1. Care and Treatment of Child Victims of Child Pornographic Exploitation (CPE) in Germany

    Science.gov (United States)

    von Weiler, Julia; Haardt-Becker, Annette; Schulte, Simone

    2010-01-01

    The online distribution of abusive images has risen dramatically over recent years and this raises many questions concerning the children within the images, particularly in relation to identification and provision of services. From October 2004 until September 2007, Innocence in Danger e.V. conducted an empirical study concerning the care and…

  2. The effect of artificial accelerated weathering on the mechanical properties of maxillofacial polymers PDMS and CPE.

    Science.gov (United States)

    Eleni, P N; Krokida, M K; Polyzois, G L

    2009-06-01

    The effect of UVA-UVB irradiation on the mechanical properties of three different industrial types of polydimethylsiloxane and chlorinated polyethylene samples, used in maxillofacial prostheses, was investigated in this study. Mechanical properties and thermal analysis are commonly used to determine the structural changes and mechanical strength. An aging chamber was used in order to simulate the solar radiation and assess natural aging. Compression and tensile tests were conducted on a Zwick testing machine. Durometer Shore A hardness measurements were carried out in a CV digital Shore A durometer according to ASTM D 2240. Glass transition temperature was evaluated with a differential scanning calorimeter. Simple mathematical models were developed to correlate the measured properties with irradiation time. The effect of UVA-UVB irradiation on compressive behavior affected model parameters. Significant deterioration seems to occur due to irradiation in samples.

  3. Presença de Staphylococcus spp. produtores de enterotoxinas e da toxina da síndrome do choque tóxico em manipuladores de queijo de cabra Presence of Staphylococcus strains producer of enterotoxins and toxic shock toxin syndrome isolated from goat's cheese handlers

    Directory of Open Access Journals (Sweden)

    L.S. Rapini

    2005-12-01

    Full Text Available Agruparam-se 167 cepas de Staphylococcus, isoladas de diferentes sítios (fossas nasais, orofaringe, palma das mãos e leitos subungueais, de dois manipuladores de queijos de leite de cabra, em pools (45, de acordo com a similaridade da espécie e o local de origem, e testou-se o seu potencial de produção de enterotoxinas (SE A, B, C e D, e da toxina da síndrome do choque tóxico (TSST-1. Constatou-se que 62,2% dos pools foram capazes de produzir, de forma individual ou associada, SEA (33,3%; SEB (46,7%; SEC (8,9%; SED (4,4% e TSST-1 (4,4%. Dos pools enterotoxigênicos, 96,4% corresponderam a espécies coagulase negativa (Staphylococcus epidermidis e Staphylococcus cohnii. A capacidade de produção de SE e de TSST-1 pelas cepas de Staphylococcus spp. isoladas dos manipuladores, além de reafirmar sua importância na transmissão de intoxicações de origem alimentar, enfatiza a necessidade imprescindível da adoção de condutas higiênicas e sanitárias durante a manipulação do alimento.A total of 167 strains of Staphylococcus isolated from nasal cavities, oropharynx, palm of hands and subunguial of two goat's cheese handlers were collected. The strains were pooled (45 according to the species similarity and place of origin and tested for the production of enterotoxins (SE A, B, C, D and toxic shock toxin syndrome (TSST-1. It was observed that 62.2% of the pools presented the capacity to produce, individually or in association, SEA (33.3%; SEB (46.7%; SEC (8.9%; SED (4.4% and TSST-1 (4.4%. From the enterotoxigenic pools, 96.4% corresponded to species negative coagulase (Staphylococcus epidermidis and Staphylococcus cohnii. The capacity to produce SE and TSST-1 by Staphylococcus spp. strains isolated from food handlers reaffirms its hole on the transmission of food poisoning, beyond emphasizing the indispensable necessity of the adoption of satisfactory hygienic and sanitary procedures during the food manufacture.

  4. Contagem de Staphylococcus sp. e detecção de enterotoxinas estafilocócicas e toxina da síndrome do choque tóxico em amostras de leite cru refrigerado Staphylococcus sp. counting and detection of staphylococcal enterotoxins and toxic shock toxin syndrome from cooled raw milk

    Directory of Open Access Journals (Sweden)

    H.C. Lamaita

    2005-10-01

    Full Text Available Analisaram-se 80 amostras de leite cru refrigerado a 4°C e estocado por 48 horas em tanques refrigeradores de propriedades rurais do estado de Minas Gerais quanto à contagem e identificação de Staphylococcus sp. e detecção de enterotoxinas estafilocócicas (SE e da toxina da síndrome do choque tóxico (TSST-1. Staphylococcus sp. foi detectado em 100% das amostras de leite de tanque refrigerador em contagens que variaram de 1,0 × 10(5 a 2,5 × 10(7 UFC/ml (média = 5,60 log UFC/ml; s = 0,53 e CV = 9,5%. Isolaram-se e identificaram-se 436 estirpes como: S. aureus, S hyicus, S. epidermidis, S. intermedius, S. cohnii, S. sciuri, S. schleirferi e S. delphini. As estirpes de mesmo perfil bioquímico, oriundas da mesma amostra, foram agrupadas (pools e induzidas a produzir SE e TSST-1. A detecção dessas enterotoxinas foi feita pelo método optimum sensitivity plate, usando-se técnica de celofane sobre ágar. Identificou-se a produção de SEA, SEB, SEC, SED e de TSST-1 em percentuais variados. Dos 138 pools preparados, 91 produziram, pelo menos, uma toxina isoladamente ou em associação a outras toxinas. Dos pools enterotoxigênicos, 24,6% eram coagulase positiva e 41,3%, coagulase negativa. A confirmação de estirpes enterotoxigênicas de Staphylococcus coagulase negativa isoladas de amostras de leite é importante em relação à saúde pública.In order to count and identify Staphylococcus sp., the detection of the Staphylococcal enterotoxins (SE and toxic shock toxin syndrome (TSST-1, 80 raw milk samples cooled at 4°C and stored in bulk tanks for 48 hours in different farms from Minas Gerais State were analyzed. Staphylococcus sp. was observed in all samples and the counts varied from 1.0 × 10(5 to 2.5 × 10(7 CFU/ml (mean = 5.60 log CFU/ml; sd = 0.53 and CV = 9.46 %. A total of 436 strains of Staphylococcus were isolated and identified as S. aureus, S hyicus, S. epidermidis, S. intermedius, S. cohnii, S. sciuri, S. schleirferi and S

  5. Staphylococcal enterotoxins stimulate lymphoma-associated immune dysregulation

    DEFF Research Database (Denmark)

    Krejsgaard, Thorbjørn Frej; Willerslev-Olsen, Andreas; Lindahl, Lise Maria

    2014-01-01

    a cascade of events involving cell-cell and asymmetric cytokine interactions between malignant and benign T cells, which stimulated the malignant T cells to express high levels of IL-10. Much evidence supports that malignant activation of the Stat3/IL-10 axis plays a key role in driving the immune...... dysregulation and severe immunodeficiency that characteristically develops in CTCL patients. The present findings thereby establish a novel link between SEs and immune dysregulation in CTCL strengthening the rationale for antibiotic treatment of colonized patients with severe or progressive disease....

  6. Prevalence, antibiotic-resistance properties and enterotoxin gene ...

    African Journals Online (AJOL)

    Methods: Three-hundred milk-based infant foods were collected and immediately transferred to the laboratory. ... and entFM (55.5 %) were the most commonly detected enterotoxigenic genes. Bacteria showed the ... conditions like pasteurization and sterilization. [2,3]. ... spaghetti, noodle, milk powder and infant formula.

  7. Prevalence, antibiotic-resistance properties and enterotoxin gene ...

    African Journals Online (AJOL)

    milk-based infant foods in Iran, represent an important public health issue which should be considered ... Keywords: Prevalence, Bacillus cereus, Antibiotic resistance, Enterotoxigenic genes, Milk-based infant food. Tropical Journal of Pharmaceutical Research is indexed by Science ..... and cereals collected in Korea.

  8. Sporadic diarrhoea due to Clostridium perfringens in children aged ...

    African Journals Online (AJOL)

    Fred

    2004-07-25

    Jul 25, 2004 ... After overnight incubation, the total viable count was done by counting the colonies in each dilution series using the Miles and. Misra technique (Miles and Misra, 1938.). The EYM plates were also examined for detection of lecithinase, lipase and proteolytic enzyme production (Barrow and Feltham, 1993).

  9. A Quantitative Electrochemiluminescence Assay for Clostridium perfringens alpha toxin

    Science.gov (United States)

    2006-08-10

    Doyle, L.R. Beuchat, T.J. Montville (Eds.), Food Microbiology : Fundamentals and Fron- tiers, Second ed., ASM Press, Washington, D.C., 2001, pp. 351...D.E. Lorant, A.E. Bryant, G.A. Zimmerman, T.M. McIn- tyre, D.L. Stevens, S.M. Prescott , Alpha toxin from Clostridium per- fringens induces

  10. Prevalence of enteropathogens and their antibiotic sensitivity pattern in puppies with hemorrhagic gastroenteritis

    Directory of Open Access Journals (Sweden)

    A. Kokila Priya

    2017-08-01

    Full Text Available Aim: Hemorrhagic gastroenteritis (HGE ranging from mild to severe forms is commonly encountered in puppies. The aim of the study was to identify the prevalence of common enteropathogens and the antibiotic sensitivity pattern in puppies reported with HGE. Materials and Methods: The canine HGE activity index, with little modification, was adopted to identify Grade III/ severely affected puppies below 6 months of age. Fecal polymerase chain reaction (PCR assay was employed to screen and compare the enteropathogens in puppies with hemorrhagic diarrhea and healthy control. Results: Canine parvovirus 2b was identified in 90.3% of the diarrheic and 10% of the non-diarrheic healthy puppies. Clostridium difficile was identified in all the diarrheic puppies and in 80% of the healthy puppies. Among the diarrheic puppies, 17.7% were positive for Clostridium perfringens enterotoxin, 9.7% were positive for C. perfringens alpha toxin, 6.4% were positive for Escherichia coli shiga toxin, 6.4% were positive for E. coli enterotoxin (LT, and 3.2% were positive for canine distemper virus. Whereas, none of the healthy puppies were positive for these bacteria and toxins. Fecal antibiotic sensitivity test pattern revealed gentamicin to be sensitive in 95% of the cases, azithromycin in 50%, enrofloxacin in 25%, cefotaxime in 20%, and tetracycline in 5% of the cases. Conclusion: Parvoviral enteritis is predominant among puppies. Yet, bacteria and their toxins also play an important role in HGE. Gentamicin has higher sensitivity against the enteropathogens associated with the condition.

  11. Toxins as biological weapons for terror-characteristics, challenges and medical countermeasures: a mini-review.

    Science.gov (United States)

    Berger, Tamar; Eisenkraft, Arik; Bar-Haim, Erez; Kassirer, Michael; Aran, Adi Avniel; Fogel, Itay

    2016-01-01

    Toxins are hazardous biochemical compounds derived from bacteria, fungi, or plants. Some have mechanisms of action and physical properties that make them amenable for use as potential warfare agents. Currently, some toxins are classified as potential biological weapons, although they have several differences from classic living bio-terror pathogens and some similarities to manmade chemical warfare agents. This review focuses on category A and B bio-terror toxins recognized by the Centers for Disease Control and Prevention: Botulinum neurotoxin, staphylococcal enterotoxin B, Clostridium perfringens epsilon toxin, and ricin. Their derivation, pathogenesis, mechanism of action, associated clinical signs and symptoms, diagnosis, and treatment are discussed in detail. Given their expected covert use, the primary diagnostic challenge in toxin exposure is the early detection of morbidity clusters, apart from background morbidity, after a relatively short incubation period. For this reason, it is important that clinicians be familiar with the clinical manifestations of toxins and the appropriate methods of management and countermeasures.

  12. Pilot Scale Production and Testing of a Recombinant Staphylococcal Enterotoxin (SEB) Triple Mutant

    Science.gov (United States)

    2017-09-01

    Polymerase Chain Reaction . J. Food Prot. 2000, 63, (4), 479–488. 6. Ulrich, R.G.; Olson, M.A.; Bavari, S. Development of Engineered Vaccines...TR-1471 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) Joint Program Executive Office for Chemical and Biological Defense, Joint Project...distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT: The use of chemically or thermally inactivated biothreat toxins in detection

  13. Stress-caused Anergy of Leukocytes towards Staphylococcal enterotoxin B and Exposure Transcriptome Signatures

    Science.gov (United States)

    2015-05-28

    concerted immune depletion was highly pronounced in the case of genes involved in synthesis /secretion of chemokines and antigen presentation. (c) The 21...biosynthetic process 48545 8.03E-03 12 Response to steroid hormone stimulus 16126 9.50E-03 5 Sterol biosynthetic process 6950 1.01E-02 44 Response to

  14. Genetic mapping of the regulator gene determining enterotoxin synthesis in Vibrio cholerae

    International Nuclear Information System (INIS)

    Smirnova, N.I.; Livanova, L.F.; Shaginyan, I.A.; Motin, V.L.

    1986-01-01

    Data on the genetic mapping of mutation tox-7 (the mutation affecting the synthesis of the cholera toxin) were obtained by conjugation crosses between the atoxigenic donor strain Vibrio cholerae Eltor and the toxigenic recipient strain V. cholera classica. The molecular and genetic analysis of the Tox - recombinants indicated that, when the synthesis of the cholera toxin is disrupted in these strains, the tox-7 mutation (which impairs the regulator gene tox) is gained. Close linkage between the tox-7 and pur-63 mutations was established (during the selection procedure there was 81.1% combined transfer with respect to marker pur-63 situated in the donor strain chromosome more proximal than mutation tox-7). The markers were localized in the following order in the region under investigation: asp-cys-nal-pur-61-trp-his-pur-63-tox-7-ile

  15. Staphylococcus enterotoxin A modulates interleukin 15-induced signaling and mitogenesis in human T cells

    DEFF Research Database (Denmark)

    Gerwien, J; Kaltoft, K; Nielsen, M

    1998-01-01

    the anti-mitogenic effect of SEA on cytokine-induced proliferation and the pro-mitogenic effect of PMA. In contrast, inhibitors of PP1, PP2A, protein kinase C (PKC), phosphatidyl-inositol-3-kinase (PI-3K) and mammalian target of rapamycin (mTOR) are unable to inhibit the effects of SEA. In a SEA "non...

  16. Inhibition of Biological Activity of Staphylococcal Enterotoxin A (SEA) by Apple Juice and Apple Polyphenols

    Science.gov (United States)

    The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal entertoxin A (SEA), a single-chain protein that consists of 233 amino acid residues with a molecular weight of 27 078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, dia...

  17. Bacillus anthracis Edema Toxin Inhibits Staphylococcus aureus Enterotoxin B Effects in Vitro: A Potential Protein Therapeutic?

    Science.gov (United States)

    2005-10-01

    5). Inherent characteristics of edema toxin and other procaryotic adenylate cyclases from Bordetella pertussis, Pseudomonas aeruginosa, and Yersinia...by mouse peritoneal macrophages: the role of cellular cyclic AMP. Immunology 64:719–724. 12. Krakauer, T. 1999. Induction of CC chemokines in human

  18. Combination treatment of clostridium perfringens spores to freezing and/or gamma irradiation

    International Nuclear Information System (INIS)

    El-Fouly, M.Z.; El-Zawahry, Y.A.; Aziz, N.H.

    1985-01-01

    Freezing process alone caused relatively low decrease in viable count of suspended spores in minced meat while it decreased the spore numbers suspended in saline solution by more than one log cycle especially in case of the Egyptian strain. An abrupt decrease in viable counts of clostridium spores was observed by application dose of 1KGY either before or after freezing followed by gradual decrease of viable counts up to 15 KGY. The synergestic effect of combined treatment was clearly obvious for spores suspended in minced meat, which usually contains protective agents which increase the resistance of microorganisms against the separate treatment of radiation of freezing especially with spores of NCTC 8798 strain. Freezing the saline suspending medium before or after irradiation after the sensitivity of clostridium spores by only small extent and gave negative synergestic effect in some treatment. The percentages of injured spores due to the combined treatment were ranged between 15-100% of the viable counts. The percentage of injured spores tended to increase as the radiation dose levels increased

  19. Predicting growth of C. perfringens in ready-to-eat foods kept hot for three hours

    DEFF Research Database (Denmark)

    Hansen, Solvej Katrine Holm; Hansen, Tina Beck

    2013-01-01

    hours with varying characteristics such as pH, NaCl and cooling constant. Theoretical cooling constants were estimated at different locations in a small and large food (meatball and liver paste) using a variety of realistic heat transfer coefficients (5-500 W∙m-2∙K-1) in a simulation software. Based...

  20. In vitro inhibition of Clostridium difficile and Clostridium perfringens by commercial probiotic strains

    DEFF Research Database (Denmark)

    Schoster, A.; Kokotovic, Branko; Permin, Anders

    2013-01-01

    of this study was to examine the in vitro inhibitory effects of selected commercial bacterial strains on pathogenic clostridia and their growth characteristics under simulated gastrointestinal conditions.The inhibitory effects of 17 commercial strains of Lactobacillus (n = 16) and Bifidobacterium (n = 1...

  1. Potential for growth of Clostridium perfringens from spores in scrapple during cooling

    Science.gov (United States)

    Scrapple is an ethnic food produced/consumed almost exclusively in the Middle Atlantic states of the U.S. It is typically made from ground pork trimmings, seasonings, cornmeal, and flour. This mixture is cooked and then shaped into loaves that are cooled and subsequently stored refrigerated until sl...

  2. Effect of individual or combined treatment of heat or radiation on clostridium perfringens spores

    Energy Technology Data Exchange (ETDEWEB)

    El-Zawahry, Y A; El-Fouly, M Z; Aziz, N H

    1986-01-01

    Separate treatments of high temperature had considerable effect on Cl.perfrigens spores suspended in saline solution especially at 90 and 100[sup 0]C, while 70 and 80[sup 0]C had only slight effect on the spores viabilty. The decimal reduction times (D[sub T]) were 33.7, 26, 4, 10.7 and 2.8 at 70, 80, 90 and 100[sup 0]C for NCTC 8798 strain and were 45.1, 27.1, 10.2 and 4.0 for the Egyptian strain at the same degrees of temperature respectively. Heat treatment pre-irradiation at 70 and 80[sup 0]C for 30 and 60 min decreased the viable spore numbers by about 0.5 to 3.0 log cycles, but the treatment had no effect on increasing the sensitivity of the rest spores to radiation. The decimal reduction dose (D[sub 10]-value) for the spores was almost the same as the control but there was a tendency to reduce the shoulder part in the radiation response curve especially when the spores were subjected to 80[sup 0]C for 60 min. On the other hand, irradiation pre-heat treatment with doses from 1-10 KGY was sufficient to decrease the spore numbers from 0.2 to 5.0 log cycles and had a sensitizing effect on subsequently heated spores especially those exposed to 90 and 100[sup 0]C. Meanwhile the rate of inactivation for spores exposed to 70 and 80[sup 0]C after irradiation increased only during the first ten minutes. Thereafter, the rate of inactivation was almost the same for the non-irradiated spores. The D[sub 10]-values for the spores irradiated with 10 KGY were 0.77 and 0.84 minutes for NCTC 8798 strain and Egyptian strain at 100[sup 0]C respectively and the spores were completely destroyed before 5 minutes.

  3. Lyophilized Carnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged with Clostridium perfringens

    DEFF Research Database (Denmark)

    Jozefiak, D; Sip, A; Rutkowski, A

    2012-01-01

    isolates. In total, 480 one-day-old male Ross 308 chicks were randomly assigned to 4 experimental groups (12 replicate pens of 10 birds per treatment). The diets were either nonsupplemented or supplemented with a lyophilized preparation of divercin AS7. On d 18, 19, and 20, half of the birds were...

  4. Identification of bilirubin reduction products formed by Clostridium perfringens isolated from human neonatal fecal flora

    Czech Academy of Sciences Publication Activity Database

    Vítek, L.; Majer, F.; Muchová, L.; Zelenka, J.; Jirásková, A.; Branny, Pavel; Malina, J.; Ubik, Karel

    2006-01-01

    Roč. 833, - (2006), s. 149-157 ISSN 1570-0232 R&D Projects: GA ČR GA310/02/1436 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z40550506 Keywords : bilirubin * bacteria l reduction * intestinal microflora Subject RIV: EE - Microbiology, Virology Impact factor: 2.647, year: 2006

  5. 9 CFR 113.111 - Clostridium Perfringens Type C Toxoid and Bacterin-Toxoid.

    Science.gov (United States)

    2010-01-01

    ... tested for purity, safety, and potency as prescribed in this section. Any serial found unsatisfactory by... provided in this paragraph. (1) When used in this test, the following words and terms shall mean: (i... dissolving 1 gram of peptone and 0.25 grams of sodium chloride in each 100 ml of distilled water; adjusting...

  6. 9 CFR 113.112 - Clostridium Perfringens Type D Toxoid and Bacterin-Toxoid.

    Science.gov (United States)

    2010-01-01

    ... tested for purity, safety, and potency as prescribed in this section. Any serial found unsatisfactory by... provided in this paragraph. (1) When used in this test, the following words and terms shall mean: (i... distilled water; adjusting the pH to 7.2; autoclaving at 250 °F for 25 minutes; and storing at 4 °C until...

  7. Detection of Staphylococcus Aureus Enterotoxin A and B Genes with PCR-EIA and a Hand-Held Electrochemical Sensor

    National Research Council Canada - National Science Library

    Aitichou, Mohamed; Henkins, Robert; Sultana, Afroz M; Ulrich, Robert G; Ibrahim, M. S

    2004-01-01

    ... S. aureus DNA, and genomic DNA from Alcaligens, Bacillus, Bacteroides, Bordetella, Burkholderia, Clostridium, Comanonas, Enterobacter, Enterococcus, Escherichia, Francisella, Haemophilus, Klebsiella...

  8. Monoclonal antibodies protect from Staphylococcal Enterotoxin K (SEK) induced toxic shock and sepsis by USA300 Staphylococcus aureus.

    Science.gov (United States)

    Aguilar, Jorge L; Varshney, Avanish K; Pechuan, Ximo; Dutta, Kaushik; Nosanchuk, Joshua D; Fries, Bettina C

    2017-08-18

    Staphylococcus aureus is a leading infectious cause of life-threatening disease in humans, yet there is currently no vaccine to combat this bacterium. The pathogenesis of S. aureus is mediated by a diverse array of protein toxins including a large family of secreted pyrogenic superantigens. Neutralization of superantigens, including SEB and TSST-1, has proven to be protective in several animal models of toxic shock and sepsis. We demonstrate, for the first time, that a far more prevalent staphylococcal superantigen, SEK, can also induce lethal shock in mice. Additionally, we describe monoclonal antibodies (mAbs) that inhibit SEK-induced mitogenicity as well as protect against SEK-induced lethality, and enhance survival from S. aureus septicemia in murine models. MAb-4G3 (IgG2b), mAb-5G2 (IgG1), and mAb-9H2 (IgG1), all inhibit SEK-induced proliferation and cytokine production of human immune cells. We then demonstrate that passive immunization with a combination of mAb-4G3 and mAb-5G4, 2 mAbs that do not compete for epitope(s) on SEK, significantly enhance survival in a murine model of SEK-induced toxic shock (p = 0.006). In the setting of sepsis, passive immunization with this combination of mAbs also significantly enhances survival in mice after challenge with CA-MRSA strain USA300 (p = 0.03). Furthermore, septic mice that received mAb treatment in conjunction with vancomycin exhibit less morbidity than mice treated with vancomycin alone. Taken together, these findings suggest that the contribution of SEK to S. aureus pathogenesis may be greater than previously appreciated, and that adjunctive therapy with passive immunotherapy against SEs may be beneficial.

  9. Food compounds inhibit Staphylococcus aureus bacteria and the toxicity of Staphylococcus Enterotoxin A (SEA) associated with atopic dermatitis

    Science.gov (United States)

    Atopic dermatitis or eczema is characterized by skin rashes and itching is an inflammatory disease that affects 10-20% of children and 1-3% of adults. Staphylococcus aureus bacteria are present on the skin of nearly all patients with atopic dermatitis. Antibiotics that suppress colonization of S. au...

  10. Staphylococcal enterotoxin-A directly stimulates signal transduction and interferon-gamma production in psoriatic T-cell lines

    DEFF Research Database (Denmark)

    Nielsen, M B; Odum, N; Gerwien, J

    1998-01-01

    class II. Here we address the question of whether SEA can directly activate psoriatic T cells in the absence of professional antigen-presenting cells. We show that SEA induces i) tyrosine phosphorylation of several proteins, ii) downregulation of the T-cell receptor (TCR), and iii) production......-mediated proliferation. In contrast, SEA with a mutation in the MHC class II alpha-binding site induces IFN-gamma and a qualitatively changed tyrosine phosphorylation profile. Both mutations delete the co-stimulatory effect on cytokine-mediated proliferation. This suggests that both MHC class II binding sites...

  11. Dietary n-3 PUFAs augment caspase 8 activation in Staphylococcal aureus enterotoxin B stimulated T-cells

    Energy Technology Data Exchange (ETDEWEB)

    Gill, R. [Department of Immunology and Microbiology, Wayne State University, Detroit, MI (United States); Jen, K.L. [Department of Nutrition and Food Science, Wayne State University, Detroit, MI (United States); Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI (United States); McCabe, M.J.J. [Department of Environmental Medicine, University of Rochester, Rochester, NY (United States); Rosenspire, A., E-mail: arosenspire@wayne.edu [Department of Immunology and Microbiology, Wayne State University, Detroit, MI (United States); Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI (United States)

    2016-10-15

    Epidemiological studies have linked consumption of n-3 PUFAs with a variety of beneficial health benefits, particularly with respect to putative anti-inflammatory effects. Unfortunately, many of these results remain somewhat controversial because in most instances there has not been a linkage to specific molecular mechanisms. For instance, dietary exposure to low levels of mercury has been shown to be damaging to neural development, but concomitant ingestion of n-3 PUFAs as occurs during consumption of fish, has been shown to counteract the detrimental effects. As the mechanisms mediating the neurotoxicity of environmental mercury are not fully delineated, it is difficult to conceptualize a testable molecular mechanism explaining how n-3 PUFAs negate its neurotoxic effects. However, environmental exposure to mercury also has been linked to increased autoimmunity. By way of a molecular understanding of this immuno-toxic association, disruption of CD95 signaling is well established as a triggering factor for autoimmunity, and we have previously shown that environmentally relevant in vitro and dietary exposures to mercury interfere with CD95 signaling. In particular we have shown that activation of caspase 8, as well as downstream activation of caspase 3, in response to CD95 agonist stimulation is depressed by mercury. More recently we have shown in vitro that the n-3 PUFA docosahexaenoic acid counteracts the negative effect of mercury on CD95 signaling by restoring caspase activity. We hypothesized that concomitant ingestion of n-3 PUFAs with mercury might be protective from the immuno-toxic effects of mercury, as it is with mercury's neuro-toxic effects, and in the case of immuno-toxicity this would be related to restoration of CD95 signal strength. We now show that dietary ingestion of n-3 PUFAs generally promotes CD95 signaling by upregulating caspase 8 activation. Apart from accounting for the ability of n-3 PUFAs to specifically counteract autoimmune sequelae of mercury exposure, this novel finding for the first time suggests a testable molecular mechanism explaining the overall anti-inflammatory properties of n-3 PUFAs. - Highlights: • Dietary n-3 PUFAs counter Hg{sup 2+} immunotoxicity • Hg{sup 2+} interference with SEB-mediated signal transduction is ameliorated by n-3 PUFA rich diets. • Dietary n-3 PUFAs augment SEB-mediated activation of caspase 8 in vivo.

  12. Dietary n-3 PUFAs augment caspase 8 activation in Staphylococcal aureus enterotoxin B stimulated T-cells

    International Nuclear Information System (INIS)

    Gill, R.; Jen, K.L.; McCabe, M.J.J.; Rosenspire, A.

    2016-01-01

    Epidemiological studies have linked consumption of n-3 PUFAs with a variety of beneficial health benefits, particularly with respect to putative anti-inflammatory effects. Unfortunately, many of these results remain somewhat controversial because in most instances there has not been a linkage to specific molecular mechanisms. For instance, dietary exposure to low levels of mercury has been shown to be damaging to neural development, but concomitant ingestion of n-3 PUFAs as occurs during consumption of fish, has been shown to counteract the detrimental effects. As the mechanisms mediating the neurotoxicity of environmental mercury are not fully delineated, it is difficult to conceptualize a testable molecular mechanism explaining how n-3 PUFAs negate its neurotoxic effects. However, environmental exposure to mercury also has been linked to increased autoimmunity. By way of a molecular understanding of this immuno-toxic association, disruption of CD95 signaling is well established as a triggering factor for autoimmunity, and we have previously shown that environmentally relevant in vitro and dietary exposures to mercury interfere with CD95 signaling. In particular we have shown that activation of caspase 8, as well as downstream activation of caspase 3, in response to CD95 agonist stimulation is depressed by mercury. More recently we have shown in vitro that the n-3 PUFA docosahexaenoic acid counteracts the negative effect of mercury on CD95 signaling by restoring caspase activity. We hypothesized that concomitant ingestion of n-3 PUFAs with mercury might be protective from the immuno-toxic effects of mercury, as it is with mercury's neuro-toxic effects, and in the case of immuno-toxicity this would be related to restoration of CD95 signal strength. We now show that dietary ingestion of n-3 PUFAs generally promotes CD95 signaling by upregulating caspase 8 activation. Apart from accounting for the ability of n-3 PUFAs to specifically counteract autoimmune sequelae of mercury exposure, this novel finding for the first time suggests a testable molecular mechanism explaining the overall anti-inflammatory properties of n-3 PUFAs. - Highlights: • Dietary n-3 PUFAs counter Hg 2+ immunotoxicity • Hg 2+ interference with SEB-mediated signal transduction is ameliorated by n-3 PUFA rich diets. • Dietary n-3 PUFAs augment SEB-mediated activation of caspase 8 in vivo

  13. Staphylococcal Enterotoxins, Toxic Shock Syndrome Toxin-I, and Streptococcal Pyrogenic Exotoxins: Some Basic Biology of Bacterial Superantigens

    National Research Council Canada - National Science Library

    Krakauer, Teresa

    2003-01-01

    Staphylococcus aureus and Streptococcus pyogenes are facultative gram-positive cocci that play an important role in a myriad of human illnesses, including food poisoning, skin infections, pharyngitis...

  14. Staphylococcus aureus enterotoxin A (SEA) stimulates STAT3 activation and IL-17 expression in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Willerslev-Olsen, Andreas; Krejsgaard, Thorbjørn; Lindahl, Lise Maria

    2016-01-01

    cells. The response is induced via IL-2 receptor common g chain cytokines and a Janus kinase 3 (JAK3)-dependent pathway in malignant T cells, and blocked by tofacitinib, a clinical-grade JAK3 inhibitor. In conclusion, we demonstrate that SEA induces cell cross talk-dependent activation of STAT3...

  15. CPE--A New Perspective: The Impact of the Technology Revolution. Proceedings of the Computer Performance Evaluation Users Group Meeting (19th, San Francisco, California, October 25-28, 1983). Final Report. Reports on Computer Science and Technology.

    Science.gov (United States)

    Mobray, Deborah, Ed.

    Papers on local area networks (LANs), modelling techniques, software improvement, capacity planning, software engineering, microcomputers and end user computing, cost accounting and chargeback, configuration and performance management, and benchmarking presented at this conference include: (1) "Theoretical Performance Analysis of Virtual…

  16. Growth of enterotoxigenic Staphylococcus aureus in povi masima, a traditional Pacific island food.

    Science.gov (United States)

    Wong, T L; Whyte, R J; Graham, C G; Saunders, D; Schumacher, J; Hudson, J A

    2004-01-01

    To obtain preliminary data on the microbiology and hurdles to pathogen growth in the traditional Pacific Island food, povi masima, which is essentially beef brisket cured in brine. Six containers of povi masima were prepared and two were inoculated with five enterotoxigenic strains of Staphyloccocus aureus. The povi masima were divided into two lots each containing two uninoculated control and an inoculated container. Lot 1 was incubated at room temperature (20 degrees C) and lot 2 under refrigeration (4-5 degrees C) for up to 98 days. During storage, samples were removed and tested for aerobic plate count, coagulase-producing Staphylococci, Clostridium perfringens, staphylococcal enterotoxin and various chemical parameters of the food. Coagulase-producing Staphylococci and aerobic plate counts grew to high levels in both the inoculated and uninoculated lots stored at room temperature, but enterotoxin was only detected at one time point in these lots and this may represent a false positive result. The concentration of NaCl in the meat increased with time as concentrations equilibrated, and nitrite was rapidly lost in those lots stored at room temperature. Storage at 4-5 degrees C prevented proliferation of coagulase-producing Staphylococci. For safe curing and storage, this food should be kept under refrigeration as this prevented growth of staphylococci. Optimum storage would also be achieved with improved attempts to ensure equal distribution of NaCl prior to storage. Under conditions traditionally used to cure and store this food, enterotoxigenic staphylococci can grow to numbers where toxigenesis might occur, especially during the early stages of curing where the salt has not diffused from the brine into the meat.

  17. Detergent-Resistant Membrane Microdomains Facilitate Ib Oligomer Formation and Biological Activity of Clostridium perfringens Iota-Toxin

    National Research Council Canada - National Science Library

    Hale, Martha

    2004-01-01

    ...) were extracted with cold Triton X-100. Western blotting revealed that Ib oligomers localized in DRMs extracted from Vero, but not MRC-5, cells while monomeric Ib was detected in the detergent-soluble fractions of both cell types...

  18. Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment

    DEFF Research Database (Denmark)

    Duan, Zhi; Holst Hansen, Terese; Hansen, Tina Beck

    OBJECTIVE Sous-vide cooking and molecular gastronomy has started a wave of experimenting with Low Temperature Long Time (LTLT) heat treatments. Heat treatments, at temperatures as low as 50°C, have been suggested by celebrity chefs. LTLT treatments often take hours to reach to the final core...

  19. In-vitro growth characteristics of commercial probiotic strains and their potential for inhibition of Clostridium difficile and Clostridium perfringens

    DEFF Research Database (Denmark)

    Schoster, A.; Permin, A.; Kokotovic, Branko

    2012-01-01

    . To study growth characteristics of 17 commercial probiotic strains (Lactobacilli n=16, Bifidobacteria n=1) MRS broth was adjusted to pH 2 or 4 or supplemented with 0.15% or 0.3% bile. Growth was measured at 0 and 24h and compared spectrophotometrically to control growth in standard MRS broth. Growth under...

  20. IN-VITRO GROWTH CHARACTERISTICS OF COMMERCIAL PROBIOTIC STRAINS AND THEIR POTENTIAL FOR INHIBITION OF CLOSTRIDIUM DIFFICILE AND CLOSTRDIDUM PERFRINGENS

    DEFF Research Database (Denmark)

    Schoster, Angelika; Kokotovic, Branko; Permin, Anders

    . To study growth characteristics of 17 commercial probiotic strains (Lactobacilli n=16, Bifidobacteria n=1) MRS broth was adjusted to pH 2 or 4 or supplemented with 0.15% or 0.3% bile. Growth was measured at 0 and 24h and compared spectrophotometrically to control growth in standard MRS broth. Growth under...

  1. Inhibition of C. difficile and C. perfringens by commercial and potential probiotic strains and their in-vitro growth characteristics

    DEFF Research Database (Denmark)

    Schoster, A.; Kokotovic, Branko; Permin, A.

    2012-01-01

    strains (Lactobacilli n=16, Bifidobacteria n=1) on growth of clostridia spp was assessed in an agar well diffusion assay and broth co-culture experiment, using supernatant harvested at different growth phases and with and without pH adjustment. To study growth characteristics MRS broth was adjusted to pH2...

  2. Evaluatie van de membraanfiltratiemethode op mCP-agar voor bepaling van sporen van Clostridium perfringens in water

    NARCIS (Netherlands)

    Schets FM; Medema GJ; LWL

    1995-01-01

    Current Dutch and European drinking water standards include criteria for spores of sulphite reducing clostridia. This has some inherent disadvantages. The reproducibility of the enumeration method for spores of sulphite reducing clostridia (SSRC) in Sulphite Cycloserine Agar (SCA) is poor. Some

  3. 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.

  4. A Rapid and Simple Real-Time PCR Assay for Detecting Foodborne Pathogenic Bacteria in Human Feces.

    Science.gov (United States)

    Hanabara, Yutaro; Ueda, Yutaka

    2016-11-22

    A rapid, simple method for detecting foodborne pathogenic bacteria in human feces is greatly needed. Here, we examined the efficacy of a method that employs a combination of a commercial PCR master mix, which is insensitive to PCR inhibitors, and a DNA extraction method which used sodium dodecyl benzene sulfonate (SDBS), and Tween 20 to counteract the inhibitory effects of SDBS on the PCR assay. This method could detect the target genes (stx1 and stx2 of enterohemorrhagic Escherichia coli, invA of Salmonella Enteritidis, tdh of Vibrio parahaemolyticus, gyrA of Campylobacter jejuni, ceuE of Campylobacter coli, SEA of Staphylococcus aureus, ces of Bacillus cereus, and cpe of Clostridium perfringens) in a fecal suspension containing 1.0 × 10 1 to 1.0 × 10 3 CFU/ml. Furthermore, the assay was neither inhibited nor influenced by individual differences among the fecal samples of 10 subjects or fecal concentration (40-160 mg/ml in the fecal suspension). When we attempted to detect the genes of pathogenic bacteria in 4 actual clinical cases, we found that this method was more sensitive than standard culture method. These results showed that this assay is a rapid, simple detection method for foodborne pathogenic bacteria in human feces.

  5. Epidemisk stigning i forekomsten af carbapenemase-producerende enterobakterier i Danmark

    DEFF Research Database (Denmark)

    Wang, Mikala; Ellermann-Eriksen, Svend; Hansen, Dennis Schrøder

    2016-01-01

    Carbapenemase-producing Enterobacteriaceae (CPE) are extremely multiresistant bacteria with few or no treatment options. Infections with CPE are associated with a mortality of 40-50%. In Denmark, CPE were first detected in 2008. Prior to 2013 the CPE incidence was low, but since then the incidence...

  6. Quantification of gut lesions in a subclinical necrotic enteritis model

    DEFF Research Database (Denmark)

    Gholamiandehkordi, Ahmad R.; Timbermont, Leen; Lanckriet, Anouk

    2007-01-01

    Currently Clostridium perfringens-induced necrotic enteritis is a major problem in broiler flocks. In the present study, broilers were inoculated with a combination of Eimeria maxima or overdose coccidial vaccine (one inoculation) with C. perfringens (repeated inoculations). Single C. perfringens...... in combination with multiple oral C. perfringens inoculations is a suitable model for necrotic enteritis without inducing mortality of the animals. C. perfringens and Eimeria act synergistically in inducing grossly visible gut damage....

  7. Ant-infecting Ophiocordyceps genomes reveal a high diversity of potential behavioral manipulation genes and a possible major role for enterotoxins

    NARCIS (Netherlands)

    De Bekker, Charissa; Ohm, Robin A.; Evans, Harry C.; Brachmann, Andreas; Hughes, David P

    2017-01-01

    Much can be gained from revealing the mechanisms fungal entomopathogens employ. Especially intriguing are fungal parasites that manipulate insect behavior because, presumably, they secrete a wealth of bioactive compounds. To gain more insight into their strategies, we compared the genomes of five

  8. Spreading of genes encoding enterotoxins, haemolysins, adhesin and biofilm among methicillin resistant Staphylococcus aureus strains with staphylococcal cassette chromosome mec type IIIA isolated from burn patients.

    Science.gov (United States)

    Motallebi, Mitra; Jabalameli, Fereshteh; Asadollahi, Kheirollah; Taherikalani, Morovat; Emaneini, Mohammad

    2016-08-01

    The emergence of antibiotic-resistant Staphylococcus aureus in particular methicillin-resistant S. aureus (MRSA) is an important concern in burn medical centers either in Iran or worldwide. A total of 128 S. aureus isolates were collected from wound infection of burn patients during June 2013 to June 2014. Multiplex-polymerase chain reaction (MPCR) assay was performed for the characterization of the staphylococcal cassette chromosome mec (SCCmec). Genes encoding virulence factors and biofilm were targeted by PCR. Of 128 S. aureus isolates, 77 (60.1%) isolates were MRSA. Fifty four (70.1%) isolates were identified as SCCmec type IIIA. The most frequently detected toxin genes among MRSA isolates with SCCmec type IIIA were sea (64.1%) and hla (51.8%). The rate of coexistence of sea with hla and sea with hla and hlb was 37% and12.9%, respectively. The sec, eta, tst, pvl, hla and hlb genes were not detected in any of the MRSA isolates. The most prevalent genes encoding biofilm was eno, found in 61.1% of isolates, followed by fib and icaA found in 48.1% and 38.8% of the isolates, respectively. The rate of coexistence of fib + eno + icaA + icaD and fib + eno was 20.3% and 9.2%, respectively. The ebps gene was not detected in any of the isolates. In conclusion, our study indicated that the sea, hla, fib and icaA were most frequent genes encoding virulence factors among MRSA with SCCmec type IIIA isolated from burn wound infection. Moreover, the results of this study shows that the rate of coexistence of genes encoding different virulence factor were high. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Persistent production of TH2-type cytokines and polyclonal B cell activation after chronic administration of staphylococcal enterotoxin B in mice

    NARCIS (Netherlands)

    Florquin, S.; Amraoui, Z.; Goldman, M.

    1996-01-01

    In order to study the immunopathological consequences of repeated exposure to bacterial superantigens, we evaluated the production of cytokines, the profile of serum immunoglobulins and the tissue damage in BALB/c mice injected twice a week for 3 weeks with 50 micrograms of staphylococcal

  10. X-ray crystal structure of the passenger domain of plasmid encoded toxin(Pet), an autotransporter enterotoxin from enteroaggregative Escherichia coli (EAEC)

    Energy Technology Data Exchange (ETDEWEB)

    Domingo Meza-Aguilar, J. [Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F. (Mexico); Fromme, Petra [Department of Chemistry and Biochemistry, Arizona State University, Physical Sciences BLDG D-102, Tempe, AZ 85287 (United States); Torres-Larios, Alfredo [Instituto de Fisiología Celular UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Mendoza-Hernández, Guillermo [Instituto de Química UNAM, Ciudad Universitaria Coyoacán 04510, D.F (Mexico); Hernandez-Chiñas, Ulises [Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F. (Mexico); Arreguin-Espinosa de los Monteros, Roberto A. [Instituto de Química UNAM, Ciudad Universitaria Coyoacán 04510, D.F (Mexico); and others

    2014-03-07

    Highlights: • X-ray crystal structure of the passenger domain of Plasmid encoded toxin at 2.3 Å. • Structural differences between Pet passenger domain and EspP protein are described. • High flexibility of the C-terminal beta helix is structurally assigned. - Abstract: Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.3 Å resolution which is a cause of acute diarrhea in both developing and industrialized countries. Pet is a cytoskeleton-altering toxin that induces loss of actin stress fibers. While Pet (pdb code: 4OM9) shows only a sequence identity of 50% compared to the closest related protein sequence, extracellular serine protease plasmid (EspP) the structural features of both proteins are conserved. A closer structural look reveals that Pet contains a β-pleaded sheet at the sequence region of residues 181–190, the corresponding structural domain in EspP consists of a coiled loop. Secondary, the Pet passenger domain features a more pronounced beta sheet between residues 135 and 143 compared to the structure of EspP.

  11. Cloning and Expression of Fusion Genes of Domain A-1 Protective Antigen of Bacillus Anthracis and Shigella Enterotoxin B Subunit (Stxb In E. Coil

    Directory of Open Access Journals (Sweden)

    AH ahmadi

    2015-02-01

    Conclusion: The findings of the current study revealed that this antigen can be raised as an anti-cancer and recombinant vaccine candidate against types of Shigella, Escherichia coli and Bacillus anthracis which can be due to such factors as identification of antigen(PA by antibody PA20, its apoptosis induction properties, property of immunogenicity, adjuvant and delivery of STxB protein and high expression levels of Gb3 in human cancer cells.

  12. Therapeutic Inhibition of Pro-Inflammatory Signaling and Toxicity to Staphylococcal Enterotoxin B by a Synthetic Dimeric BB-Loop Mimetic of MyD88

    Science.gov (United States)

    2012-07-27

    56 stock solution and 75 ml of the 16 dilution buffer was mixed with 25 ml of the supernatant, incubated for 30 min at 65 oC to inactivate endogenous ...shock by staphylococcal pyrogenic exotoxin type C. Infect Immun 36: 123–128. Meier survival analysis and log-rank tests were performed to compare

  13. Gene expression and functional annotation of the human and mouse choroid plexus epithelium.

    Directory of Open Access Journals (Sweden)

    Sarah F Janssen

    Full Text Available BACKGROUND: The choroid plexus epithelium (CPE is a lobed neuro-epithelial structure that forms the outer blood-brain barrier. The CPE protrudes into the brain ventricles and produces the cerebrospinal fluid (CSF, which is crucial for brain homeostasis. Malfunction of the CPE is possibly implicated in disorders like Alzheimer disease, hydrocephalus or glaucoma. To study human genetic diseases and potential new therapies, mouse models are widely used. This requires a detailed knowledge of similarities and differences in gene expression and functional annotation between the species. The aim of this study is to analyze and compare gene expression and functional annotation of healthy human and mouse CPE. METHODS: We performed 44k Agilent microarray hybridizations with RNA derived from laser dissected healthy human and mouse CPE cells. We functionally annotated and compared the gene expression data of human and mouse CPE using the knowledge database Ingenuity. We searched for common and species specific gene expression patterns and function between human and mouse CPE. We also made a comparison with previously published CPE human and mouse gene expression data. RESULTS: Overall, the human and mouse CPE transcriptomes are very similar. Their major functionalities included epithelial junctions, transport, energy production, neuro-endocrine signaling, as well as immunological, neurological and hematological functions and disorders. The mouse CPE presented two additional functions not found in the human CPE: carbohydrate metabolism and a more extensive list of (neural developmental functions. We found three genes specifically expressed in the mouse CPE compared to human CPE, being ACE, PON1 and TRIM3 and no human specifically expressed CPE genes compared to mouse CPE. CONCLUSION: Human and mouse CPE transcriptomes are very similar, and display many common functionalities. Nonetheless, we also identified a few genes and pathways which suggest that the CPE

  14. The effect of New Neonatal Porcine Diarrhoea Syndrome (NNPDS) on average daily gain and mortality in 4 Danish pig herds

    DEFF Research Database (Denmark)

    Kongsted, Hanne; Stege, Helle; Toft, Nils

    2014-01-01

    , which is not caused by enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens (C. perfringens) type A/C, Clostridium difficile (C. difficile), rotavirus A, coronavirus, Cystoisospora suis, Strongyloides ransomi, Giardia spp or Cryptosporidium spp. Results: Piglets were estimated to have...

  15. Carbapenemase-producerende enterobacteriën in Nederland : Onopgemerkte versprewiding naar verschillende regio's.

    NARCIS (Netherlands)

    Leenstra, T; Bosch, T; Vlek, A L; Bonten, M J M; van der Lubben, I M; de Greeff, S C

    2017-01-01

    - Carbapenemase producing Enterobacteriaceae (CPE), including Klebsiella pneumoniae and Escherichia coli, are only sporadically seen in the Netherlands and then mainly in patients who have been transferred from foreign hospitals.- CPE are resistant to virtually all beta-lactam antibiotics, including

  16. What Influences Malaysian Nurses to Participate in Continuing Professional Education Activities?

    Directory of Open Access Journals (Sweden)

    Mei Chan Chong, RN, MSc, SCM

    2011-03-01

    Conclusions: Implementation of mandatory CPE is considered an important measure to increase nurse's participation in CPE. However, effective planning that takes into consideration the learning needs of nurses is recommended.

  17. Studies on flame retardancy of radiation crosslinked PE foam

    International Nuclear Information System (INIS)

    Yang Huili; Yao Zhanhai; Xu Jun

    1996-01-01

    CPE, DBDPO and Sb 2 O 3 were used as flame-retardant of PE foam. Effect of CPE on PE foam under radiation and it's flame-retardancy were studied. The result showed that CPE can enhance radiation cross-linking of PE, and trinary of addition being made of CPE, DBDPO and Sb 2 O 3 made oxygen index of PE foam achieve over 30, and self-extinguish, it did not influence manufacture and mechanical properties of PE foam

  18. Genome-Wide Transcriptional Profiling of Clostridium perfringens SM101 during Sporulatio