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1

Clostridium perfringens Epsilon-Toxin Acts on MDCK Cells by Forming a Large Membrane Complex  

Microsoft Academic Search

Epsilon-toxin is produced by Clostridium perfringens types B and D and is responsible for a rapidly fatal enterotoxemia in animals, which is characterized by edema in several organs due to an increase in blood vessel permeability. The Madin-Darby canine kidney (MDCK) cell line has been found to be susceptible to epsilon- toxin (D. W. Payne, E. D. Williamson, H. Havard,

LAETITIA PETIT; MARYSE GIBERT; DANIEL GILLET; CHRISTINE LAURENT-WINTER; PATRICE BOQUET; MICHEL R. POPOFF

1997-01-01

2

Evaluation of different fluids for detection of Clostridium perfringens type D epsilon toxin in sheep with experimental enterotoxemia  

Microsoft Academic Search

Enterotoxemia caused by Clostridium perfringens type D is a highly lethal disease of sheep, goats and other ruminants. The diagnosis of this condition is usually confirmed by detection of epsilon toxin, a major exotoxin produced by C. perfringens types B and D, in the intestinal content of affected animals. It has been suggested that other body fluids can also be

Jorge E. Layana; Mariano E. Fernandez Miyakawa; Francisco A. Uzal

2006-01-01

3

Functional and structural characterization of soluble recombinant epsilon toxin of Clostridium perfringens D, causative agent of enterotoxaemia  

Microsoft Academic Search

Clostridium perfringens types B and D are responsible for enterotoxaemia, one of the major causes of cattle mortality and is therefore of great economic\\u000a concern. The epsilon toxin produced by the organism is the major antigenic determinant and has been directly implicated for\\u000a the disease causation. In the present paper, we evaluated the biological activity of the recombinant epsilon toxin

Deepika Dayal Mathur; Sachin Deshmukh; Himani Kaushik; Lalit C. Garg

2010-01-01

4

Detection of the etx gene (epsilon-toxin inducer) in plasmids of high molecular weight in Clostridium perfringens type D.  

PubMed

The purpose of this work is to correlate the production of epsilon-toxin in a set of strains of Clostridium perfringens type D with the presence of the etx gene, either genomic or in plasmids. Total DNA obtained from strains with a different level of toxin production was explored by PCR and all the strains showed the amplification signal. Different methods were used to obtain plasmid profiles and all of the bands were assayed by PCR. The detection of the etx gene was only shown in several high molecular plasmids. These results were confirmed by a Southern blot. We suggest that the localization of the etx gene in different plasmids could be associated with the epsilon-toxin production level. PMID:10397325

Bentancor, A B; Fermepín, M R; Bentancor, L D; de Torres, R A

1999-07-01

5

Identification of amino acids important for binding of Clostridium perfringens epsilon toxin to host cells and to HAVCR1  

PubMed Central

Clostridium perfringens epsilon toxin belongs to the aerolysin-like family of pore-forming toxins and is one of the most potent bacterial toxins known. The epsilon toxin causes fatal enterotoxemia in sheep, goats, and possibly humans. Evidence indicates that the toxin binds to protein receptors including hepatitis A virus cellular receptor 1 (HAVCR1), but the region of the toxin responsible for cell binding has not been identified. In the present study, we identify amino acids within the epsilon toxin important for this cell interaction. Site-specific mutagenesis was used to investigate the role of a surface-accessible cluster of aromatic amino acids, and purified mutant proteins were tested in a series of cell-culture assays to assess cytotoxic activity and cell binding. When added to cells, four mutant proteins (Etx-Y29E, Etx-Y30E, Etx-Y36E and Etx-Y196E) were severely impaired in their ability to not only kill host cells, but also in their ability to permeabilize the plasma membrane. Circular dichroism spectroscopy and thermal stability studies revealed that the wild-type and mutant proteins were similarly folded. Additional experiments revealed that these mutant proteins were defective in binding to host cells and to HAVCR1. These data indicate that an amino acid motif including Y29, Y30, Y36, and Y196 is important for the ability of epsilon toxin to interact with cells and HAVCR1.

Ivie, Susan E.; McClain, Mark S.

2012-01-01

6

Recombinant expression of in silico identified Bcell epitope of epsilon toxin of Clostridium perfringens in translational fusion with a carrier protein  

PubMed Central

Epsilon toxin secreted by Clostridium perfringens types B and D has been directly implicated as the causative agent of fatal enterotoxemia in domestic animals. The aim of the present study is to use in silico approach for identification of B-cell epitope(s) of epsilon toxin, and its expression in fusion with a carrier protein to analyze its potential as vaccine candidate(s). Using different computational analyses and bioinformatics tools, a number of antigenic determinant regions of epsilon toxin were identified. One of the B cell epitopes of epsilon toxin comprising the region (amino acids 40-62) was identified as a promising antigenic determinant. This Etx epitope (Etx40-62) was cloned and expressed as a translational fusion with B-subunit of heat labile enterotoxin (LTB) of E. coli in a secretory expression system. Similar to the native LTB, the recombinant fusion protein retained the ability to pentamerize and bind to GM1 ganglioside receptor of LTB. The rLTB.Etx40-62 could be detected both with anti-Etx and anti-LTB antisera. The rLTB.Etx40-62 fusion protein thus can be evaluated as a potential vaccine candidate against C. perfringens. Abbreviations aa - amino acid(s), Etx - epsilon toxin of Clostridium perfringens, LTB - B-subunit of heat labile enterotoxin of E. coli.

Kaushik, Himani; Deshmukh, Sachin; Mathur, Deepika Dayal; Tiwari, Archana; Garg, Lalit C

2013-01-01

7

Attack of the nervous system by Clostridium perfringens Epsilon toxin: From disease to mode of action on neural cells.  

PubMed

Epsilon toxin (ET), produced by Clostridium perfringens types B and D, ranks among the four most potent poisonous substances known so far. ET-intoxication is responsible for enterotoxaemia in animals, mainly sheep and goats. This disease comprises several manifestations indicating the attack of the nervous system. This review aims to summarize the effects of ET on central nervous system. ET binds to endothelial cells of brain capillary vessels before passing through the blood-brain barrier. Therefore, it induces perivascular oedema and accumulates into brain. ET binding to different brain structures and to different component in the brain indicates regional susceptibility to the toxin. Histological examination has revealed nerve tissue and cellular lesions, which may be directly or indirectly caused by ET. The naturally occurring disease caused by ET-intoxication can be reproduced experimentally in rodents. In mice and rats, ET recognizes receptor at the surface of different neural cell types, including certain neurons (e.g. the granule cells in cerebellum) as well as oligodendrocytes, which are the glial cells responsible for the axons myelination. Moreover, ET induces release of glutamate and other transmitters, leading to firing of neural network. The precise mode of action of ET on neural cells remains to be determined. PMID:23632158

Wioland, Laetitia; Dupont, Jean-Luc; Bossu, Jean-Louis; Popoff, Michel R; Poulain, Bernard

2013-04-27

8

The detection of Clostridium perfringens epsilon antitoxin in rabbit serum by monoclonal antibody based competition ELISA.  

PubMed

A competitive enzyme-linked immunosorbent assay (CELISA) has been developed, standardized and compared with the toxin neutralization (TN) test performed in mice for the measurement of antibody responses in rabbits vaccinated with clostridial vaccines. In CELISA, sera were tested at a single dilution for their ability to compete with the reaction between a monoclonal antibody, which neutralizes epsilon toxin, and epsilon toxoid coated on to a solid phase. The results of the two tests correlated well. CELISA was specific, rapid, reproducible and simple to perform and offered an alternative to the TN test that reduced the requirement for experimental animals in the potency testing of clostridial vaccines. PMID:2715150

Sojka, M G; White, V J; Thorns, C J; Roeder, P L

1989-04-01

9

The Clostridium perfringens?-toxin  

Microsoft Academic Search

The gene encoding the ?-(cpa) is present in all strains of Clostridium perfringens , and the purified ?-toxin has been shown to be a zinc-containing phospholipase C enzyme, which is preferentially active towards phosphatidylcholine and sphingomyelin. The ?-toxin is haemolytic as a result if its ability to hydrolyse cell membrane phospholipids and this activity distinguishes it from many other related

Richard W Titball; Claire E Naylor; Ajit K Basak

1999-01-01

10

Clostridium perfringens Spore-Lytic Enzymes.  

National Technical Information Service (NTIS)

Enzymes which cause the germination of Clostridium perfringens spores were isolated and characterized. Two were investigated in detail. One was extracted from spores of the same organism. The second was excreted by vegetative cells of C. perfringens. The ...

R. Labbe

1983-01-01

11

Epsilon-Toxin Is Required for Most Clostridium perfringens Type D Vegetative Culture Supernatants To Cause Lethality in the Mouse Intravenous Injection Model  

PubMed Central

Clostridium perfringens type D enterotoxemias have significant economic impact by causing rapid death of several domestic animal species. Consequently, domestic animals are commonly vaccinated, at varying efficacy, with inactivated type D vegetative supernatants. Improved type D vaccines might become possible if the lethal toxins produced by type D isolates were characterized and the contributions of those toxins to supernatant-induced lethality were established. Therefore, the current study evaluated the presence of lethal toxins in supernatants prepared from late-log-phase vegetative cultures of a large collection of genotype D isolates. Under this growth condition, most genotype D isolates produced variable levels of at least three different lethal toxins, including epsilon-toxin (ETX). To model the rapid lethality of type D enterotoxemias, studies were conducted involving intravenous (i.v.) injection of genotype D vegetative supernatants into mice, which were then observed for neurotoxic distress. Those experiments demonstrated a correlation between ETX (but not alpha-toxin or perfringolysin O) levels in late-log-phase genotype D supernatants and lethality. Consistent with the known proteolytic activation requirement for ETX toxicity, trypsin pretreatment was required for, or substantially increased, the lethality of nearly all of the tested genotype D vegetative supernatants. Finally, the lethality of these trypsin-pretreated genotype D supernatants could be completely neutralized by an ETX-specific monoclonal antibody but not by an alpha-toxin-specific monoclonal antibody. Collectively, these results indicate that, under the experimental conditions used in the present study, ETX is necessary for the lethal properties of most genotype D vegetative supernatants in the mouse i.v. injection model.

Sayeed, Sameera; Fernandez-Miyakawa, M. E.; Fisher, Derek J.; Adams, Vicki; Poon, Rachael; Rood, Julian I.; Uzal, Francisco A.; McClane, Bruce A.

2005-01-01

12

The enteric toxins of Clostridium perfringens  

Microsoft Academic Search

The Gram-positive pathogenClostridium perfringens is a major cause of human and veterinary enteric disease largely because this bacterium can produce several toxins when present\\u000a inside the gastrointestinal tract. The enteric toxins of C. perfringens share two common features: (1) they are all single polypeptides of modest (~25—35 kDa) size, although lacking in sequence\\u000a homology, and (2) they generally act by

J. G. Smedley; D. J. Fisher; S. Sayeed; G. Chakrabarti; B. A. McClane

13

The enteric toxins of Clostridium perfringens  

Microsoft Academic Search

The Gram-positive pathogen Clostridium perfringens is a major cause of human and veterinary enteric disease largely because this bacterium can produce several toxins when present inside the gastrointestinal tract. The enteric toxins of C. perfringens share two common features: (1) they are all single polypeptides of modest (~25–35 kDa) size, although lacking in sequence homology, and (2) they generally act by

J. G. Smedley III; D. J. Fisher; S. Sayeed; G. Chakrabarti; B. A. McClane

2004-01-01

14

Quantitative Electrochemiluminescence Assay for Clostridium perfringens alpha toxin.  

National Technical Information Service (NTIS)

Described is a rapid direct sandwich format electrochemiluminescence assay for identifying and assaying Clostridium perfringens alpha toxin. Biotinylated antibodies to C. perfringens alpha toxin bound to streptavidin paramagnetic beads specifically immuno...

G. A. Merrill V. R. Rivera D. D. Neal C. Young M. A. Poli

2006-01-01

15

Recurrent diarrhea associated with enterotoxigenic Clostridium perfringens in 2 dogs.  

PubMed Central

Two dogs were diagnosed with enterotoxigenic Clostridium perfringens-associated diarrhea. Diarrhea was responsive to antimicrobial therapy, but recurred after treatment was ceased. Clostridium perfringens enterotoxin was present in feces during diarrheic episodes but not when feces were normal. Both dogs responded to a prolonged course of oral cephalexin and dietary modification.

Weese, J S; Greenwood, S J; Staempfli, H R

2001-01-01

16

Clostridium perfringens in Meat and Meat Products  

PubMed Central

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.

Hall, Herbert E.; Angelotti, Robert

1965-01-01

17

Affinity chromatography purification of Clostridium perfringens enterotoxin.  

PubMed Central

Anti-enterotoxin immunoglobulins immobilized on CH-Sepharose or CNBr-Sepharose were used for affinity chromatography purification of Clostridium perfringens enterotoxin. Cell extracts containing enterotoxin or partially purified toxin preparations were applied to the column and nonspecifically-bound protein was eluted. NaOH was used to elute specifically bound toxin. The purity of enterotoxin purified by Sephadex G-100 chromatography followed by affinity chromatography appears similar to toxin highly purified by conventional means. The procedure can be used successfully for the rapid (less than 2 h) purification of small amounts of enterotoxin. Images

Scott, V N; Duncan, C L

1975-01-01

18

Factors Contributing to Heat Resistance of Clostridium perfringens Endospores  

Microsoft Academic Search

The endospores formed by strains of type A Clostridium perfringens that produce the C. perfringens entero- toxin (CPE) are known to be more resistant to heat and cold than strains that do not produce this toxin. The high heat resistance of these spores allows them to survive the cooking process, leading to a large number of food-poisoning cases each year.

Benjamin Orsburn; Stephen B. Melville; David L. Popham

2008-01-01

19

Cloning and sequencing of the Clostridium perfringens enterotoxin gene  

Microsoft Academic Search

Several gene banks of Clostridium perfringens in E. coli were constructed. Using a mixture of synthetic 29-mer DNA probes clones were selected containing inserts from the C. perfringens gene coding for the enterotoxin. This has allowed sequencing of the complete gene and its flanking regions. The decuded amino acid sequence (320 a.a.) was found to differ at several sites from

MARIJKE VAN DAMME-JONGSTEN; Karel Wernars; Servé Notermans

1989-01-01

20

Acid Exposure Enhances Sporulation of Certain Strains of Clostridium perfringens  

Microsoft Academic Search

A gastroenteritis results when Clostridium perfringens is ingested in high numbers and sporulates releasing enterotoxin in the intestines. Since the organism must pass through the stomach, its ability to form spores may be affected by the acidic environment. Five strains of C. perfringens were exposed to acidic conditions and then assessed for survival and their ability to form spores. An

D. M. Wrigley; H. D. S. H. Hanwella; B. L. Thon

1995-01-01

21

Toxigenic Clostridium perfringens from a parvovirus-infected dog.  

PubMed

A strain of Clostridium perfringens, type A, has been isolated from the intestine of a dog which died from parvovirus infection. This Clostridium strain produces a toxin which can be detected by counterimmunoelectrophoresis, using C. difficile antitoxin, and produces cytotoxicity in WI-38 cell culture. Cytopathology can be blocked by C. difficile antitoxin. Its role in canine parvovirus infection is unknown. PMID:6277989

Tilton, R C; Van Kruiningen, H J; Kwasnik, I; Ryan, R W

1981-12-01

22

Toxigenic Clostridium perfringens from a Parvovirus-Infected Dog  

PubMed Central

A strain of Clostridium perfringens, type A, has been isolated from the intestine of a dog which died from parvovirus infection. This Clostridium strain produces a toxin which can be detected by counterimmunoelectrophoresis, using C. difficile antitoxin, and produces cytotoxicity in WI-38 cell culture. Cytopathology can be blocked by C. difficile antitoxin. Its role in canine parvovirus infection is unknown.

Tilton, R. C.; Van Kruiningen, H. J.; Kwasnik, I.; Ryan, R. W.

1981-01-01

23

Detection and characterization of Clostridium perfringens in the feces of healthy and diarrheic dogs.  

PubMed

Clostridium perfringens has been implicated as a cause of diarrhea in dogs. The objectives of this study were to compare 2 culture methods and to evaluate a multiplex polymerase chain reaction (PCR) assay to detect C. perfringens toxin genes alpha (?), beta (? ), beta 2 (?2), epsilon (?), iota (?), and C. perfringens enterotoxin (cpe) from canine isolates. Fecal samples were collected from clinically normal non-diarrheic (ND) dogs, (n = 105) and diarrheic dogs (DD, n = 54). Clostridium perfringens was isolated by directly inoculating stool onto 5% sheep blood agar (SBA) and enrichment in brain-heart infusion (BHI) broth, followed by inoculation onto SBA. Isolates were tested by multiplex PCR for the presence of ?, ?, ?2, ?, ?, and cpe genes. C. perfringens was isolated from 84% of ND samples using direct culture and from 87.6% with enrichment (P = 0.79). In the DD group, corresponding isolation rates were 90.7% and 93.8% (P = 0.65). All isolates possessed the ? toxin gene. Beta (?), ?2, ?, ?, and cpe toxin genes were identified in 4.5%, 1.1%, 3.4%, 1.1%, and 14.8% of ND isolates, respectively. In the DD group, ? and ?2 were identified in 5%, ? and ? were not identified, and the cpe gene was identified in 16.9% of isolates. Enrichment with BHI broth did not significantly increase the yield of C. perfringens, but it did increase the time and cost of the procedure. C. perfringens toxin genes were present in equal proportions in both the ND and DD groups (P ? 0.15 to 0.6). Within the parameters of this study, culture of C. perfringens and PCR for toxin genes is of limited diagnostic usefulness due to its high prevalence in normal dogs and the lack of apparent difference in the distribution of toxin genes between normal and diarrheic dogs. PMID:23277693

Goldstein, Michael R; Kruth, Stephen A; Bersenas, Alexa M E; Holowaychuk, Marie K; Weese, J Scott

2012-07-01

24

PRODUCTION AND CHARACTERIZATION OF CLOSTRIDIUM PERFRINGENS "BURSTING FACTOR"  

PubMed Central

Fredette, V. (University of Montreal, Montreal, Canada), A. Forget, and G. Vinet. Production and characterization of Clostridium perfringens “bursting factor.” J. Bacteriol. 83:1177–1182. 1962.—Virulent cultures of Clostridium perfringens in which none of the presently known toxic or enzymatic fractions could be detected either in vitro or in vivo were shown to contain “bursting factor.” This new antigen, although devoid of toxicity, exerts a triggerlike or aggressinlike action on washed perfringens bacilli, a characteristic which sets it apart from collagenase or kappa-toxin with which it could have been confused previously. Pathogenesis of C. perfringens gas gangrene can therefore be explained more satisfactorily with the “bursting factor” than with any previously known fraction from the filtrates of these cultures.

Fredette, V.; Forget, A.; Vinet, G.

1962-01-01

25

Frequency of Clostridium perfringens types in Jordanian sheep.  

PubMed

778 fecal samples from 29 Jordanian sheep flocks were examined for the presence of Clostridium perfringens. 252 field strains were isolated and typed by the enzyme immunosorbent assay. The presence of C. perfringens types B, C and D in Jordanian sheep was confirmed. Type D was found in 55% of the flocks examined. Types B and C were each isolated from 7% of the flocks examined. The proteinase activity of isolated type B field strains was similar to that of type B reference strains. According to the results, it does not seem to be necessary to include locally isolated C. perfringens strains in the Jordanian vaccine production. PMID:7858351

Younan, M; Both, H; Müller, W

1994-08-01

26

Rapid Technique for the Enumeration of Clostridium perfringens  

PubMed Central

A new medium, Tryptone-sulfite-neomycin (TSN) agar, and an incubation procedure for the enumeration of Clostridium perfringens are described. Tolerance to neomycin, optimal growth at 46 C, and sulfite-reducing properties of C. perfringens were used as a basis for development of the medium. Comparisons were made between sulfite-polymyxin-sulfadiazine (SPS) agar and TSN agar at 37 and 46 C with C. perfringens and other organisms. These studies indicate the quantitative and selective superiority of TSN agar, incubated at 46 C, over SPS agar.

Marshall, Robert S.; Steenbergen, J. Frank; McClung, L. S.

1965-01-01

27

Real-time multiplex PCR assay for rapid detection and toxintyping of Clostridium perfringens toxin producing strains in feces of dairy cattle  

Microsoft Academic Search

Clostridium perfringens is an anaerobic, gram-positive, spore-forming bacterium associated with a wide variety of diseases in domestic animals and humans. We have developed dual-labeled fluorescence hybridization probe (TaqMan®)-based real-time multiplex PCR assay for detection of toxin genes alpha (cpa), beta (cpb), iota (ia), epsilon (etx), beta2 (cpb2) and enterotoxin (cpe) of C. perfringens directly from cattle feces. The assay was

A. A. Gurjar; N. V. Hegde; B. C. Love; B. M. Jayarao

2008-01-01

28

MATHEMATICAL MODELING OF GROWTH OF CLOSTRIDIUM PERFRINGENS IN COOKED BEEF  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this work was to study the growth kinetics of Clostridium perfringens spores in thermally processed ground beef and compare the suitability of the Gompertz, logistic, and Baranyi models used to describe the isothermal bacterial growth. Ground beef samples inoculated with the spores ...

29

Translational selection is operative for synonymous codon usage in Clostridium perfringens and Clostridium acetobutylicum  

Microsoft Academic Search

Here, the codon usage patterns of two Clostridium species (Clostridium perfringens and Clostridium acetobutylicum) are reported. These prokaryotes are characterized by a strong mutational bias towards A+T, a striking excess of coding sequences and purine-rich leading strands of replication, strong GC-skews and a high frequency of genomic rearrangements. As expected, it was found that the mutational bias dominates codon usage

Hector Musto; Hector Romero; Alejandro Zavala

2003-01-01

30

Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens  

PubMed Central

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant.

Silva, R. O. S.; Salvarani, F.M.; Assis, R.A.; Martins, N.R.S.; Pires, P.S.; Lobato, F.C.F.

2009-01-01

31

Development and Application of an Oral Challenge Mouse Model for Studying Clostridium perfringens Type D Infection?  

PubMed Central

Clostridium perfringens type D isolates cause enterotoxemia in sheep, goats, and probably cattle. While the major disease signs and lesions of type D animal disease are usually attributed to epsilon toxin, a class B select agent, these bacteria typically produce several lethal toxins. Understanding of disease pathogenesis and development of improved vaccines are hindered by the lack of a small-animal model mimicking natural disease caused by type D isolates. Addressing this need, we developed an oral challenge mouse model of C. perfringens type D enterotoxemia. When BALB/c mice with a sealed anus were inoculated by intragastric gavage with type D isolates, 7 of 10 type D isolates were lethal, as defined by spontaneous death or severe clinical signs necessitating euthanasia. The lethalities of the seven type D isolates varied between 14 and 100%. Clinical signs in the lethally challenged mice included seizures, convulsions, hyperexcitability, and/or depression. Mild intestinal gas distention and brain edema were observed at necropsy in a few mice, while histology showed multifocal acute tubular necrosis of the kidney and edema in the lungs of most challenged mice that developed a clinical response. When the lethality of type D isolates in this model was compared with in vitro toxin production, only a limited correlation was observed. However, mice could be protected against lethality by intravenous passive immunization with an epsilon toxin antibody prior to oral challenge. This study provides an economical new model for studying the pathogenesis of C. perfringens type D infections.

Fernandez-Miyakawa, Mariano E.; Sayeed, Sameera; Fisher, Derek J.; Poon, Rachael; Adams, Vicki; Rood, Julian I.; McClane, Bruce A.; Saputo, Julian; Uzal, Francisco A.

2007-01-01

32

Molecular Subtyping of Poultry-Associated Type A Clostridium perfringens Isolates by Repetitive-Element PCR  

PubMed Central

Clostridium perfringens strains (type A) isolated from an integrated poultry operation were subtyped using repetitive-element PCR with Dt primers. Isolates were obtained from fecal, egg shell, fluff, and carcass rinse samples as part of a previously reported temporally linked epidemiological survey. A total of 48 isolates of C. perfringens were obtained from different stages of the broiler chicken production chain from two separate breeder farms that supplied a single hatchery that in turn provided chicks to a single grow-out farm whose flocks were processed at a single plant. All 48 isolates were typeable (100% typeability) by repetitive-element PCR with Dt primers. This subtyping method was highly reproducible and discriminatory. By repetitive-element PCR with Dt primers, isolates were classified into four major branches with 12 subgroups or clades. The Simpson's index of discrimination was calculated to be 0.96 for groupings of >95% correlation. Toxin gene profiles of the isolates indicated that all of the isolates were C. perfringens alpha-toxin gene positive and 46 of 48 isolates were beta2-toxin gene positive. All strains were negative for beta- and epsilon-toxin genes. Repetitive sequence-based PCR was found to be a technically practical and reproducible means of subtyping C. perfringens libraries from specific epidemiological or production environment settings.

Siragusa, G. R.; Danyluk, M. D.; Hiett, K. L.; Wise, M. G.; Craven, S. E.

2006-01-01

33

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

PubMed

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 alpha, beta1, epsilon, eta, enterotoxin and beta2 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 beta2 toxin gene and species-specific pathological features. PMID:20391372

Badagliacca, Pietro; Di Provvido, Andrea; Scattolini, Silvia; Pompei, Giuliana; Di Giannatale, Elisabetta

34

Vero cell assay for rapid detection of Clostridium perfringens enterotoxin.  

PubMed Central

A rapid assay which measured the biological activity of Clostridium perfringens enterotoxin was developed. The method involved the rapid killing of Vero cells by enterotoxin produced by C. perfringens grown in Duncan and Strong sporulation medium. Serial dilutions of toxin were added to Vero cells either in suspension or grown as monolayers in wells of a 96-well cell tissue culture cluster plate. Vital staining of Vero cells with neutral red, followed by extraction of the dye, allowed toxin levels to be determined either visually or by optical density measurements with a micro-ELISA M580 computer program. The toxin produced was confirmed as different from the Vero toxin of Escherichia coli and the alpha and theta toxins of C. perfringens.

Mahony, D E; Gilliatt, E; Dawson, S; Stockdale, E; Lee, S H

1989-01-01

35

Clostridium perfringens sepsis and liver abscess following laparoscopic cholecystectomy  

PubMed Central

Clostridium perfringens sepsis with intravascular haemolysis is a catastrophic process with a reported mortality of between 90 to 100%. We successfully treated a case of severe clostridial infection with a liver abscess following laparoscopic cholecystectomy, the first to our knowledge. A 59-year-old man presented one week after an uneventful laparoscopic cholecystectomy with jaundice, peritonism, sepsis and acute renal failure. He was found to have a haemolytic anaemia, unconjugated hyperbilirubinemia and blood cultures grew Clostridium perfringens. A CT revealed a large gas forming abscess in the gallbladder fossa and right lobe of liver. He was treated with directed antibiotic therapy and underwent emergency laparotomy, drainage of the abscess and peritoneal washout. He required intensive care support, parenteral nutrition and inotropic support for a limited period. CT liver angiogram post op was normal. Continued renal dysfunction necessitated protracted haemofiltration. This resolved and the patient was discharged home at 2 months.

Qandeel, H; Abudeeb, H; Hammad, A; Ray, C; Sajid, M; Mahmud, S

2012-01-01

36

Detection of Clostridium perfringens ? toxin by enzyme-linked immunosorbent assay  

Microsoft Academic Search

An enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of Clostridium perfringens > toxin in intestinal contents of animals which have died of suspected C perfringens type A enterotoxaemia. The test can also be used for testing culture supernatants of C perfringens isolates for the presence of ? toxin. The test was sensitive and quantitative detecting toxin down

R. D Naylor; P. K Martin; L. T Barker

1997-01-01

37

Genetic diversity of Clostridium perfringens type A isolates from animals, food poisoning outbreaks and sludge  

Microsoft Academic Search

BACKGROUND: Clostridium perfringens, a serious pathogen, causes enteric diseases in domestic animals and food poisoning in humans. The epidemiological relationship between C. perfringens isolates from the same source has previously been investigated chiefly by pulsed-field gel electrophoresis (PFGE). In this study the genetic diversity of C. perfringens isolated from various animals, from food poisoning outbreaks and from sludge was investigated.

Anders Johansson; Anna Aspan; Elisabeth Bagge; Viveca Båverud; Björn E Engström; Karl-Erik Johansson

2006-01-01

38

Occurrence of Clostridium perfringens from different cultivated soils.  

PubMed

The occurrence of Clostridium perfringens was estimated in 750 samples originated from a variety of soils bearing various bulb crops: Brawnica oderacea (vegetable), Olea europaea, Daucus carota (carote), Solanum tuberosum (potato), Phaseolus vulgaris (green haricot), Beta vulgaris var. rapaceum (beetroot), Cucurbita pepo (squash), Allium cepa (onion), Cucumis sativus (cucumber) and Capsicum annum (pepper). All isolated strains were tested for their antimicrobial activities to amoxicillin, penicillin G, kanamycin, tetracycline, streptomycin, erythromycin, chloramphenicol and metronidazole. When considering the type of the bulb production, it was observed increased number of C. perfringens spore densities in the most undersurface bulb soils. Moreover, C. perfringens spore are likely to occur in particularly large numbers in soil contaminated by fecal matter. Additionally, there is a close relationship between the spore amount and nature of organic content. Presence of C. perfringens was associated with acidic soil. Most of our strains showed resistance to the studied antibiotics applied usually for human and veterinary care. A systematic monitoring of the cultivated soil ecosystems must include bacteriological parameters together with chemical indices of organic pollution in order to obtain information adequate for assessing their overall quality. PMID:21621626

Voidarou, C; Bezirtzoglou, E; Alexopoulos, A; Plessas, S; Stefanis, C; Papadopoulos, I; Vavias, S; Stavropoulou, E; Fotou, K; Tzora, A; Skoufos, I

2011-05-20

39

Isolation of Clostridium perfringens Type B in an Individual at First Clinical Presentation of Multiple Sclerosis Provides Clues for Environmental Triggers of the Disease  

PubMed Central

We have isolated Clostridium perfringens type B, an epsilon toxin-secreting bacillus, from a young woman at clinical presentation of Multiple Sclerosis (MS) with actively enhancing lesions on brain MRI. This finding represents the first time that C. perfringens type B has been detected in a human. Epsilon toxin’s tropism for the blood-brain barrier (BBB) and binding to oligodendrocytes/myelin makes it a provocative candidate for nascent lesion formation in MS. We examined a well-characterized population of MS patients and healthy controls for carriage of C. perfringens toxinotypes in the gastrointestinal tract. The human commensal Clostridium perfringens type A was present in approximately 50% of healthy human controls compared to only 23% in MS patients. We examined sera and CSF obtained from two tissue banks and found that immunoreactivity to ETX is 10 times more prevalent in people with MS than in healthy controls, indicating prior exposure to ETX in the MS population. C. perfringens epsilon toxin fits mechanistically with nascent MS lesion formation since these lesions are characterized by BBB permeability and oligodendrocyte cell death in the absence of an adaptive immune infiltrate.

Rumah, Kareem Rashid; Linden, Jennifer; Fischetti, Vincent A.; Vartanian, Timothy

2013-01-01

40

Isolation of Clostridium perfringens Type B in an Individual at First Clinical Presentation of Multiple Sclerosis Provides Clues for Environmental Triggers of the Disease.  

PubMed

We have isolated Clostridium perfringens type B, an epsilon toxin-secreting bacillus, from a young woman at clinical presentation of Multiple Sclerosis (MS) with actively enhancing lesions on brain MRI. This finding represents the first time that C. perfringens type B has been detected in a human. Epsilon toxin's tropism for the blood-brain barrier (BBB) and binding to oligodendrocytes/myelin makes it a provocative candidate for nascent lesion formation in MS. We examined a well-characterized population of MS patients and healthy controls for carriage of C. perfringens toxinotypes in the gastrointestinal tract. The human commensal Clostridium perfringens type A was present in approximately 50% of healthy human controls compared to only 23% in MS patients. We examined sera and CSF obtained from two tissue banks and found that immunoreactivity to ETX is 10 times more prevalent in people with MS than in healthy controls, indicating prior exposure to ETX in the MS population. C. perfringens epsilon toxin fits mechanistically with nascent MS lesion formation since these lesions are characterized by BBB permeability and oligodendrocyte cell death in the absence of an adaptive immune infiltrate. PMID:24146858

Rumah, Kareem Rashid; Linden, Jennifer; Fischetti, Vincent A; Vartanian, Timothy

2013-10-16

41

Clostridium perfringens meningitis, Plesiomonas shigelloides sepsis: A lethal combination  

PubMed Central

Summary Background: Anaerobic bacterial meningitis is rare. It is extremely unusual without a portal of entry as most cases reported have been associated with trauma or neurosurgery. Case Report: We describe this rare case of clostridium meningitis and plesiomonas sepsis in an immunocompetent adult. A 71 year old man with diabetes presented with acute onset severe headaches, obtundation and signs of severe hemolysis following a 2 week game hunting trip in the Swiss Alps. His clinical status progressed rapidly; he died 3 hours after initial presentation. Post mortem lumbar puncture was performed with CSF analysis suggestive of bacterial meningitis. Clostridium perfringens was eventually recovered from the CSF as well as in the blood. Plesiomonas shigelloides was recovered from the blood as well. Conclusions: This is the first case of blood stream infection with these two organisms in a single patient without an obvious portal of entry.

Okon, Emmanuel; Bishburg, Eliahu; Ugras, Sandra; Chan, Trini; Wang, He

2013-01-01

42

Complex transcriptional regulation of citrate metabolism in Clostridium perfringens.  

PubMed

A Gram-positive, spore-forming bacterium, Clostridium perfringens, possesses genes for citrate metabolism, which might play an important role in the utilization of citrate as a sole carbon source. In this study, we identified a chromosomal citCDEFX-mae-citS operon in C. perfringens strain 13, which is transcribed on three mRNAs of different sizes. Expression of the cit operon was significantly induced when 5 mM extracellular citrate was added to the growth medium. Most interestingly, three regulatory systems were found to be involved in the regulation of the expression of cit genes: 1) the two upstream divergent genes citG and citI; 2) two different two-component regulatory systems, CitA/CitB (TCS6 consisted of CPE0531/CPE0532) and TCS5 (CPE0518/CPE0519); and 3) the global two-component VirR/VirS-VR-RNA regulatory system known to regulate various genes for toxins and degradative enzymes. Our results suggest that in C. perfringens the citrate metabolism might be strictly controlled by a complex regulatory system. PMID:21945821

Yuan, Yonghui; Ohtani, Kaori; Yoshizawa, Satoko; Shimizu, Tohru

2011-09-21

43

Inducible Clostridium perfringens bacteriophages ?S9 and ?S63  

PubMed Central

Two inducible temperate bacteriophages ?S9 and ?S63 from Clostridium perfringens were sequenced and analyzed. Isometric heads and long non-contractile tails classify ?S9 and ?S63 in the Siphoviridae family, and their genomes consist of 39,457 bp (?S9) and 33,609 bp (?S63) linear dsDNA, respectively. ?S63 has 3?-overlapping cohesive genome ends, whereas ?S9 is the first Clostridium phage featuring an experimentally proven terminally redundant and circularly permuted genome. A total of 50 and 43 coding sequences were predicted for ?S9 and ?S63, respectively, organized into 6 distinct lifestyle-associated modules typical for temperate Siphoviruses. Putative functions could be assigned to 26 gene products of ?S9, and to 25 of ?S63. The ?S9 attB attachment and insertion site is located in a non-coding region upstream of a putative phosphorylase gene. Interestingly, ?S63 integrates into the 3? part of sigK in C. perfringens, and represents the first functional skin-element-like phage described for this genus. With respect to possible effects of lysogeny, we did not obtain evidence that ?S9 may influence sporulation of a lysogenized host. In contrast, interruption of sigK, a sporulation associated gene in various bacteria, by the ?S63 prophage insertion is more likely to affect sporulation of its carrier.

Kim, Kwang-Pyo; Born, Yannick; Lurz, Rudi; Eichenseher, Fritz; Zimmer, Markus; Loessner, Martin J.; Klumpp, Jochen

2012-01-01

44

Risk Assessment for 'Clostridium perfringens' in Ready-to-Eat and Partially Cooked Meat and Poultry Products.  

National Technical Information Service (NTIS)

The United States Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) conducted a quantitative risk assessment of Clostridium perfringens (C. perfringens) in ready-to-eat (RTE) and partially cooked meat and poultry products. The pur...

E. Crouch N. J. Golden

2005-01-01

45

Effect of heat treatment on the performance of tryptose-sulfite-cycloserine agar for enumeration of Clostridium perfringens.  

PubMed Central

Dissolving dehydrated tryptose-sulfite-cycloserine agar by only boiling or microwaving was found to inhibit Clostridium perfringens colony development in pour plates when compared with C. perfringens recovery in tryptose-sulfite-cycloserine agar prepared by autoclaving. Images

Brodsky, M H; Ciebin, B W

1979-01-01

46

A hospital outbreak of Clostridium perfringens food poisoning—implications for food hygiene review in hospitals  

Microsoft Academic Search

An outbreak of Clostridium perfringens (C. perfringens) food poisoning affected 17 of 44 (38·6%) patients interviewed on two hospital wards. A case-control study showed a statistically significant association between the consumption of roast pork and illness (P < 0·01). C. perfringens type A, untypable serotype, was isolated from samples of pre-cooked vacuum sealed pork supplied by a local meat producer.

C. M. Regan; Q. Syed; P. J. Tunstall

1995-01-01

47

NetB, a Pore-Forming Toxin from Necrotic Enteritis Strains of Clostridium perfringens  

PubMed Central

The Clostridium perfringens necrotic enteritis B-like toxin (NetB) is a recently discovered member of the ?-barrel pore-forming toxin family and is produced by a subset of avian C. perfringens type A strains. NetB is cytotoxic for avian cells and is associated with avian necrotic enteritis. This review examines the current state of knowledge of NetB: its role in pathogenesis, its distribution and expression in C. perfringens and its vaccine potential.

Keyburn, Anthony L.; Bannam, Trudi L.; Moore, Robert J.; Rood, Julian I.

2010-01-01

48

Phenotypic and genotypic characterization of tetracycline and minocycline resistance in Clostridium perfringens  

Technology Transfer Automated Retrieval System (TEKTRAN)

The aim of this study was to determine the incidence of tetracycline resistance and the prevalence of tetracycline-resistance genes in strains of Clostridium perfringens isolated from different sources between 1994 and 2005. Susceptibility to tetracycline and minocycline in C. perfringens isolates ...

49

Necrotic enteritis: Effect of barley, wheat and corn diets on proliferation of Clostridium perfringens type A  

Microsoft Academic Search

Necrotic enteritis, caused by Clostridium perfringens type A, is more prevalent in broilers fed wheat or barley diets than in those fed a corn diet. We compared the effects of wheat, barley and corn diets on in vitro proliferation of C. perfringens type A. Bacteria were inoculated into the supernatants delivered from either digested or non-digested barley, wheat and corn

C. B. Annett; J. R. Viste; M. Chirino-Trejo; H. L. Classen; D. M. Middleton; E. Simko

2002-01-01

50

Molecular Subtyping of Poultry-Associated Type A Clostridium perfringens Isolates by Repetitive-Element PCR  

Microsoft Academic Search

Clostridium perfringens strains (type A) isolated from an integrated poultry operation were subtyped using repetitive-element PCR with Dt primers. Isolates were obtained from fecal, egg shell, fluff, and carcass rinse samples as part of a previously reported temporally linked epidemiological survey. A total of 48 isolates of C. perfringens were obtained from different stages of the broiler chicken production chain

G. R. Siragusa; M. D. Danyluk; K. L. Hiett; M. G. Wise; S. E. Craven

2006-01-01

51

The genome sequence and proteome of bacteriophage ?CPV1 virulent for Clostridium perfringens  

Microsoft Academic Search

Application of bacteriophages and their lytic enzymes to control Clostridium perfringens is one potential approach to reduce the pathogen on poultry farms and in poultry-processing facilities. Bacteriophages lytic for C. perfringens were isolated from sewage, feces and broiler intestinal contents and ?CPV1, a virulent bacteriophage, was classified in the family Podoviridae. The purified virus had an icosahedral head and collar

Nikolay V. Volozhantsev; Vladimir V. Verevkin; Vasily A. Bannov; Valentina M. Krasilnikova; Vera P. Myakinina; Eugeni L. Zhilenkov; Edward A. Svetoch; Norman J. Stern; Brian B. Oakley; Bruce S. Seal

2011-01-01

52

Impedance Analysis of Ovarian Cancer Cells upon Challenge with C-terminal Clostridium Perfringens Enterotoxin  

Microsoft Academic Search

Both in vitro and animal studies in breast, prostate, and ovarian cancers have shown that clostridium perfringens enterotoxin (CPE), which binds to CLDN4, may have an important therapeutic benefit, as it is rapidly cytotoxic in tissues overexpressing CLDN4. This study sought to evaluate the ability of C-terminal clostridium perfringens enterotoxin (C-CPE), a CLDN4-targetting molecule, to disrupt tight junction barrier function.

Geoffrey Gordon; Chun-Min Lo

2007-01-01

53

Clostridium sordellii Phospholipase C: Gene Cloning and Comparison of Enzymatic and Biological Activities with Those of Clostridium perfringens and Clostridium bifermentans Phospholipase C  

Microsoft Academic Search

The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histidine- tagged (His-tag) protein, and the protein was purified to compare its enzymatic and biological activities with those of Clostridium perfringens phospholipase C (Cpa) and Clostridium bifermentans phospholipase C (Cbp). Csp was found to consist of 371 amino acid residues in the mature form and to

Tadahiro Karasawa; Xingmin Wang; Tsuneo Maegawa; Yoshio Michiwa; H. Kita; Koichi Miwa; Shinichi Nakamura

2003-01-01

54

Molecular and Cellular Basis of Microvascular Perfusion Deficits Induced by Clostridium perfringens and Clostridium septicum  

PubMed Central

Reduced tissue perfusion leading to tissue ischemia is a central component of the pathogenesis of myonecrosis caused by Clostridium perfringens. The C. perfringens ?-toxin has been shown capable of inducing these changes, but its potential synergy with perfringolysin O (?-toxin) is less well understood. Similarly, Clostridium septicum is a highly virulent causative agent of spontaneous gas gangrene, but its effect on the microcirculation has not been examined. Therefore, the aim of this study was to use intravital microscopy to examine the effects of C. perfringens and C. septicum on the functional microcirculation, coupled with the use of isogenic toxin mutants to elucidate the role of particular toxins in the resultant microvascular perfusion deficits. This study represents the first time this integrated approach has been used in the analysis of the pathological response to clostridial toxins. Culture supernatants from wild-type C. perfringens induced extensive cell death within 30 min, as assessed by in vivo uptake of propidium iodide. Furthermore, significant reductions in capillary perfusion were observed within 60 min. Depletion of either platelets or neutrophils reduced the alteration in perfusion, consistent with a role for these blood-borne cells in obstructing perfusion. In addition, mutation of either the ?-toxin or perfringolysin O structural genes attenuated the reduction in perfusion, a process that was reversed by genetic complementation. C. septicum also induced a marked reduction in perfusion, with the degree of microvascular compromise correlating with the level of the C. septicum ?-toxin. Together, these data indicate that as a result of its ability to produce ?-toxin and perfringolysin O, C. perfringens rapidly induces irreversible cellular injury and a marked reduction in microvascular perfusion. Since C. septicum induces a similar reduction in microvascular perfusion, it is postulated that this function is central to the pathogenesis of clostridial myonecrosis, irrespective of the causative bacterium.

Hickey, Michael J.; Kwan, Rain Y. Q.; Awad, Milena M.; Kennedy, Catherine L.; Young, Lauren F.; Hall, Pam; Cordner, Leanne M.; Lyras, Dena; Emmins, John J.; Rood, Julian I.

2008-01-01

55

Virulence Plasmid Diversity in Clostridium perfringens Type D Isolates? †  

PubMed Central

Clostridium perfringens type D isolates are important in biodefense and also cause natural enterotoxemias in sheep, goats, and occasionally cattle. In these isolates, the gene (etx) encoding ?-toxin is thought to reside on poorly characterized large plasmids. Type D isolates sometimes also produce other potentially plasmid-encoded toxins, including C. perfringens enterotoxin and beta2 toxin, encoded by the cpe and cbp2 genes, respectively. In the current study we demonstrated that the etx, cpe, and cpb2 genes are carried on plasmids in type D isolates and characterized the toxin-encoding plasmids to obtain insight into their genetic organization, potential transferability, and diversity. Southern blotting of pulsed-field gels showed that the etx gene of type D isolates can be present on at least five different plasmids, whose sizes range from 48 to 110 kb. The etx plasmids also typically carried IS1151 and tcp open reading frames (ORFs) known to mediate conjugative transfer of C. perfringens plasmid pCW3. PCR studies revealed that other than their tcp ORFs, etx plasmids of type D isolates do not carry substantial portions of the conserved or variable regions in the cpe plasmids of type A isolates. Southern blotting also demonstrated that in type D isolates the cpe and cpb2 genes are sometimes present on the etx plasmid. Collectively, these findings confirmed that the virulence of type D isolates is heavily plasmid dependent and indicated that (i) a single type D isolate can carry multiple virulence plasmids, (ii) a single type D virulence plasmid can carry up to three different toxin genes, and (iii) many etx plasmids should be capable of conjugative transfer.

Sayeed, Sameera; Li, Jihong; McClane, Bruce A.

2007-01-01

56

Rabbit Ileal Loop Response to Strains of Clostridium perfringens1  

PubMed Central

The ligated loop of the rabbit intestine was investigated as a possible experimental model for the study of Clostridium perfringens food poisoning. The method of preparation of the challenge inoculum was important in determining whether a given strain would provoke a response. When cultures were grown for 4 hr at 37 C in Skim Milk (Difco), 14 of 29 type A strains isolated from food-poisoning outbreaks consistently produced exudation of fluid and consequent dilation of the ileal segments. In contrast, 15 of the 18 strains derived from other sources failed to elicit a response. By use of different inoculum preparations, nearly all strains could be made to give at least an occasional positive loop reaction. Diarrhea was not obtained in rabbits by intraluminal injection into the normal ileum or by per os administration of the cultures. Lecithinase, purified and in concentrated culture supernatant fractions, failed to produce a response in the isolated ileal loops. Images

Duncan, Charles L.; Sugiyama, H.; Strong, Dorothy H.

1968-01-01

57

Characterization of a Bacteriocinogenic Plasmid in Clostridium perfringens CW55  

PubMed Central

A bacteriocinogenic strain of Clostridium perfringens was exposed to various curing agents known to accelerate the elimination of extrachromosomal DNA, and 20 independently derived mutants that had lost both the ability to produce bacteriocin and their immunity to it were isolated and characterized. All of the mutants were missing at least two specific plasmid bands seen in the agarose gel plasmid profile of the parent strain. Evidence that the two missing bands represented the open circular and closed circular forms of the same plasmid was obtained by X-ray nicking and restriction endonuclease digestion. The data indicated that bacteriocin production and immunity are controlled by a single plasmid, pCW4, with a molecular weight of 5.6 × 106 in this strain. Attempts to transfer the bacteriocinogenic plasmid were unsuccessful. Images

Mihelc, Valerie A.; Duncan, Charles L.; Chambliss, Glenn H.

1978-01-01

58

Acute Hemolysis in the Emergency Department: Think about Clostridium perfringens!  

PubMed Central

Clostridium perfringens (CP) gives several clinical settings, from an asymptomatic to a massive intravascular hemolysis. We report a case of fatal intravascular hemolysis due to CP septicemia having a hepatic supposed starting point in the emergency department. Like in many cases, the diagnosis was made when patient had already gone into shock and died. The CP septicemia often complicated the course of the digestive or genital pathologies. The alpha toxin can damage the structural integrity of the red cell membrane by means of a phospholipase activity. Nevertheless, a massive intravascular hemolysis arises only rarely in this septicemia, only from 7 to 15% of the cases. The emergency physician has to think about this complication in case of hemoglobinuria and/or signs of hemolysis associated with a septic syndrome. An immediate antibiotic treatment adapted as well as the symptomatic treatment of the spread intravascular coagulation could improve the survival of these patients.

Cecilia, Roustit; Baptiste, Valle; Benjamin, Clouzeau; Virginie, Heydel; Guillaume, Valdenaire; Philippe, Revel; Matthieu, Biais

2013-01-01

59

Characterization of Clostridium perfringens (welchii) Isolated from Market Poultry1  

PubMed Central

Strains of Clostridium perfringens capable of producing heat-resistant spores, characteristic of the food-poisoning types, were not recovered in a random survey of feces and livers of market poultry. Favorable growth response with a known food-poisoning strain indicated that the media and methods employed were adequate. Spores produced in vitro from this strain survived at 100 C for several hours. Animal feeding experiments with this strain showed that heat-resistant spores (surviving for 1 hr at 100 C) could be readily demonstrated 24 hr after oral instillation of vegetative cells in mouse feces, but not in chicken feces. One experiment suggests that this strain might adapt to the environment of the intestinal tract of chickens, but not all of the spores recovered were as heat resistant as those of the parent culture.

Yamamoto, Richard; Sadler, Walter W.; Adler, Henry E.; Stewart, George F.

1961-01-01

60

Molecular analysis of transferable tetracycline resistance plasmids from Clostridium perfringens.  

PubMed Central

Conjugative tetracycline resistance plasmids from 15 Clostridium perfringens isolates from piggeries were analyzed by restriction endonuclease digestion and agarose gel electrophoresis. Seven isolates from one farm were found to carry a 47-kilobase pair (kb) plasmid, pJIR5, which had EcoRI, XbaI, and ClaI profiles that were identical to those of a previously characterized plasmid, pCW3. An isolate from a second farm was found to carry a plasmid, pJIR6, which also was indistinguishable from pCW3. Five additional isolates from a third farm carried a 67-kb plasmid, pJIR2, which had at least 29 kb of DNA in common with pCW3. Finally, two isolates from a fourth farm were found to carry a 50-kb plasmid pJIR4, which appeared to consist of an entire pCW3 molecule with a 3-kb insertion. Comparative restriction maps of pCW3, pJIR2, and pJIR4 that identified the regions of homology among these plasmids were constructed. We suggest that many conjugative tetracycline resistance plasmids in C. perfringens may contain a pCW3-like core. Images

Abraham, L J; Rood, J I

1985-01-01

61

Factors contributing to heat resistance of Clostridium perfringens endospores.  

PubMed

The endospores formed by strains of type A Clostridium perfringens that produce the C. perfringens enterotoxin (CPE) are known to be more resistant to heat and cold than strains that do not produce this toxin. The high heat resistance of these spores allows them to survive the cooking process, leading to a large number of food-poisoning cases each year. The relative importance of factors contributing to the establishment of heat resistance in this species is currently unknown. The present study examines the spores formed by both CPE(+) and CPE(-) strains for factors known to affect heat resistance in other species. We have found that the concentrations of DPA and metal ions, the size of the spore core, and the protoplast-to-sporoplast ratio are determining factors affecting heat resistance in these strains. While the overall thickness of the spore peptidoglycan was found to be consistent in all strains, the relative amounts of cortex and germ cell wall peptidoglycan also appear to play a role in the heat resistance of these strains. PMID:18378644

Orsburn, Benjamin; Melville, Stephen B; Popham, David L

2008-03-31

62

Sporulation, Heat Resistance, and Biological Properties of Clostridium perfringens  

PubMed Central

A sporulation medium for 134 Clostridium perfringens strains, including types A, B, C, D, E, and F, was devised according to Grelet's observation that sporulation occurred when cultural environment became limited in any nutritional requirement indispensable for the growth of the organism. Sporulation took place most prominently when 10% cooked-meat broth (pH 7.2) containing 3% Proteose Peptone and 1% glucose was used for the preculture and 2% Poli Peptone medium (pH 7.8) was used for the subculture medium. Sometimes, terminal spores could be observed. A correlation between sporulation and heat resistance was examined by use of C. perfringens strains isolated from samples heated at different temperatures. Almost all strains isolated from unheated samples and from those heated at lower temperatures gave rise to spores in our sporulation medium, but the spores were weakly heat-resistant, whereas strains isolated from samples heated at 100 C for 60 min were highly heat-resistant but sporulated poorly. A majority of these heat-resistant strains were non-gelatinolytic and definitely salicin-fermenting. Images

Nishida, S.; Seo, N.; Nakagawa, M.

1969-01-01

63

Structural Basis of Clostridium perfringens Toxin Complex Formation  

SciTech Connect

The virulent properties of the common human and livestock pathogen Clostridium perfringens are attributable to a formidable battery of toxins. Among these are a number of large and highly modular carbohydrate-active enzymes, including the {mu}-toxin and sialidases, whose catalytic properties are consistent with degradation of the mucosal layer of the human gut, glycosaminoglycans, and other cellular glycans found throughout the body. The conservation of noncatalytic ancillary modules among these enzymes suggests they make significant contributions to the overall functionality of the toxins. Here, we describe the structural basis of an ultra-tight interaction (Ka = 1.44 x 1011 M-1) between the X82 and dockerin modules, which are found throughout numerous C. perfringens carbohydrate-active enzymes. Extensive hydrogen-bonding and van der Waals contacts between the X82 and dockerin modules give rise to the observed high affinity. The {mu}-toxin dockerin module in this complex is positioned {approx}180 relative to the orientation of the dockerin modules on the cohesin module surface within cellulolytic complexes. These observations represent a unique property of these clostridial toxins whereby they can associate into large, noncovalent multitoxin complexes that allow potentiation of the activities of the individual toxins by combining complementary toxin specificities.

Adams,J.; Gregg, K.; Bayer, E.; Boraston, A.; Smith, S.

2008-01-01

64

Evaluation of CP Chromo Select Agar for the enumeration of Clostridium perfringens from water.  

PubMed

The European Directive on drinking water quality has included mCP agar as the reference method for recovering Clostridium perfringens from drinking waters. In the present study, three media (mCP, TSCF and CP Chromo Select Agar) were evaluated for recovery of C. perfringens in different surface water samples. Out of 139 water samples, using a membrane filtration technique, 131 samples (94.2%) were found to be presumptively positive for C. perfringens in at least one of the culture media. Green colored colonies on CP Chromo Select Agar (CCP agar) were counted as presumptive C. perfringens isolates. Out of 483 green colonies on CCP agar, 96.3% (465 strains, indole negative) were identified as C. perfringens, and 15 strains (3.1%) were indole positive and were identified as Clostridium sordellii, Clostridium bifermentans or Clostridium tetani. Only 3 strains (0.6%) gave false positive results and were identified as Clostridium fallax, Clostridium botulinum, and Clostridium tertium. Variance analysis of the data obtained shows statistically no significant differences in the counts obtained between media employed in this work. The mCP method is very onerous for routine screening and bacterial colonies could not be used for further biochemical testing. The colonies on CCP and TSCF were easy to count and subculture for confirmation tests. TSCF detects sulfite-reducing clostridia, including species other than C. perfringens, and in some cases excessive blackening of the agar frustrated counting of the colonies. If the contamination was too high, TSCF did not consistently produce black colonies and as a consequence, the colonies were white and gave false negative results. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that CCP agar was the most useful medium for C. perfringens recovery in water samples. PMID:23816139

Manafi, Mammad; Waldherr, Kerstin; Kundi, Michael

2013-06-18

65

In vitro inhibition of Clostridium difficile and Clostridium perfringens by commercial probiotic strains.  

PubMed

Probiotics have gained importance in human and veterinary medicine to prevent and control clostridial enteric disease. Limited information is available on the ability of different probiotic bacteria used in food products to inhibit Clostridium difficile and Clostridium perfringens. The objective 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) on the reference strains of C. difficile and C. perfringens were assessed by an agar well diffusion assay and by a broth culture inhibition assay using cell-free supernatant harvested at different growth phases, with and without pH neutralization. To study growth characteristics, probiotic strains were cultivated in different acid and bile environments, and growth in the modified media was compared to growth in standard medium. In the agar well diffusion assay, supernatant obtained from two probiotic strains inhibited the growth of both reference and clinical strains of C. perfringens. This effect as seen when supernatant was assessed with and without pH neutralization. Supernatants obtained from 10 probiotic strains inhibited C. difficile only when supernatant was added without pH neutralization. In the broth culture inhibition assay, growth of C. perfringens and C. difficile was inhibited by supernatant without pH neutralization from 5 and 10 probiotic strains, respectively. All potential probiotic strains were able to grow at pH 4.0 and in the presence of 0.15% and 0.3% bile but none were able to grow or survive at pH 2.0. Altogether five probiotic strains [Lactobacillus plantarum (n = 2), Lactobacillus rhamnosus (n = 2), Bifidobacterium animalis lactis (n = 1)] were shown to inhibit all strains of C. difficile and C. perfringens. The inhibitory effect was probiotic strain-specific. Two strains showed a pH-independent inhibitory effect likely due to production of either antibiotics or bacteriocins inhibiting C. perfringens only. These strains have favourable growth characteristics for use as probiotics and their efficacy as prophylactic or therapeutic measures against clostridial enteric disease should be further evaluated by clinical trials in animals. PMID:23471038

Schoster, A; Kokotovic, B; Permin, A; Pedersen, P D; Dal Bello, F; Guardabassi, L

2013-03-05

66

Comparative Analysis of Prevalence, Risk Factors, and Molecular Epidemiology of Antibiotic-Associated Diarrhea Due to Clostridium difficile, Clostridium perfringens, and Staphylococcus aureus  

Microsoft Academic Search

We prospectively studied the comparative epidemiology and risk factors for Clostridium difficile, Clostridium perfringens, and Staphylococcus aureus antibiotic-associated diarrhea (AAD). Four thousand six hundred fifty- nine inpatient fecal specimens (11 months) were tested for C. difficile cytotoxin, C. perfringens enterotoxin, and S. aureus by Vero cell assay, enzyme-linked immunosorbent assay, and growth on fresh blood agar, respectively. Two distinct age-,

N. J. Asha; D. Tompkins; M. H. Wilcox

2006-01-01

67

Extraction of Clostridium perfringens spores from bottom sediment samples.  

PubMed Central

Two extraction-separation procedures were developed and evaluated for use in conjunction with the mCP membrane filter method for the enumeration of Clostridium perfringens spores in bottom sediments. In the more facile of the two procedures, a distilled-water suspension of the sediment sample is pulse sonicated for 10 s and allowed to settle. Portions of the supernatant are then removed for membrane filtration. This procedure is recommended for general use. The more complicated procedure is recommended for situations in which the presence of high levels of toxic materials is suspected or in which relatively low spore densities are present in fine silts. In this procedure, sonication is followed by a distilled water wash. The centrifuged sediment is resuspended in distilled water and mixed with the components of a two-phase separation system (50% polyethylene glycol in distilled water and 25% sucrose in 3 M phosphate buffer [pH 7.1]). After equilibration of the system and low-speed centrifugation, the top phase and interphase are removed, mixed, and membrane filtered. The recoveries of C. perfringens spores by the two procedures, when used in conjunction with the mCP method, were comparable to each other and significantly greater than those by the British most-probable-number method. It was estimated that more than 85% of the spores were recovered by the procedures. The precision of the sonicate-and-settle-mCP procedure was markedly better than that obtained theoretically by the most-probable-number method and approached that theoretically attributable to counting an average of 85 colonies on each of two plates.

Emerson, D J; Cabelli, V J

1982-01-01

68

Structural Insights into Clostridium perfringens Delta Toxin Pore Formation  

PubMed Central

Clostridium perfringens Delta toxin is one of the three hemolysin-like proteins produced by C. perfringens type C and possibly type B strains. One of the others, NetB, has been shown to be the major cause of Avian Nectrotic Enteritis, which following the reduction in use of antibiotics as growth promoters, has become an emerging disease of industrial poultry. Delta toxin itself is cytotoxic to the wide range of human and animal macrophages and platelets that present GM2 ganglioside on their membranes. It has sequence similarity with Staphylococcus aureus ?-pore forming toxins and is expected to heptamerize and form pores in the lipid bilayer of host cell membranes. Nevertheless, its exact mode of action remains undetermined. Here we report the 2.4 Å crystal structure of monomeric Delta toxin. The superposition of this structure with the structure of the phospholipid-bound F component of S. aureus leucocidin (LukF) revealed that the glycerol molecules bound to Delta toxin and the phospholipids in LukF are accommodated in the same hydrophobic clefts, corresponding to where the toxin is expected to latch onto the membrane, though the binding sites show significant differences. From structure-based sequence alignment with the known structure of staphylococcal ?-hemolysin, a model of the Delta toxin pore form has been built. Using electron microscopy, we have validated our model and characterized the Delta toxin pore on liposomes. These results highlight both similarities and differences in the mechanism of Delta toxin (and by extension NetB) cytotoxicity from that of the staphylococcal pore-forming toxins.

Huyet, Jessica; Naylor, Claire E.; Savva, Christos G.; Gibert, Maryse; Popoff, Michel R.; Basak, Ajit K.

2013-01-01

69

Evaluation of a Predictive Model for Clostridium perfringens Growth during Cooling  

Microsoft Academic Search

Proper temperature control is essential in minimizing Clostridium perfringens germination, growth, and toxin production. The U.S. Department of Agriculture Food Safety and Inspection Service offers two options for the cooling of meat products: follow a standard time-temperature schedule or validate that alternative cooling regimes result in no more than a 1-log CFU\\/ g increase of C. perfringens and no growth

SARAH SMITH; DONALD W. SCHAFFNER

70

Quantitative Detection of Clostridium perfringens in the Broiler Fowl Gastrointestinal Tract by Real-Time PCR  

Microsoft Academic Search

Strains of Clostridium perfringens are a frequent cause of food-borne disease and gas gangrene and are also associated with necrotic enteritis in chickens. To detect and quantify the levels of C. perfringens in the chicken gastrointestinal tract, a quantitative real-time PCR assay utilizing a fluorogenic, hydrolysis-type probe was developed and utilized to assay material retrieved from the broiler chicken cecum

Mark G. Wise; Gregory R. Siragusa

2005-01-01

71

Role of Clostridium perfringens phospholipase C in the pathogenesis of gas gangrene  

Microsoft Academic Search

Gas gangrene is an acute and devastating infection most frequently caused by Clostridium perfringens and characterized by severe myonecrosis, intravascular leukocyte accumulation, and significant thrombosis. Several lines of evidence indicate that C. perfringens phospholipase C (Cp-PLC), also called alpha-toxin, is the major virulence factor in this disease. This toxin is a Zn2+ metalloenzyme with lecithinase and sphingomyelinase activities. Its three

Marietta Flores-D??az; Alberto Alape-Girón

2003-01-01

72

The complex interactions between Clostridium perfringens enterotoxin and epithelial tight junctions  

Microsoft Academic Search

Clostridium perfringens enterotoxin (CPE) is responsible for the diarrheal symptoms of C. perfringens type A food poisoning and antibiotic-associated diarrhea. The CPE protein consists of a single 35kDa polypeptide with a C-terminal receptor-binding region and an N-terminal toxicity domain. Under appropriate conditions, CPE can interact with structural components of the epithelial tight junctions, including certain claudins and occludin. Those interactions

Bruce A. McClane

2001-01-01

73

Complete genome sequence of Clostridium perfringens, an anaerobic flesh-eater  

Microsoft Academic Search

Clostridium perfringens is a Gram-positive anaerobic spore-forming bacterium that causes life-threatening gas gangrene and mild enterotoxaemia in humans, although it colonizes as normal intestinal flora of humans and animals. The organism is known to produce a variety of toxins and enzymes that are responsible for the severe myonecrotic lesions. Here we report the complete 3,031,430-bp sequence of C. perfringens strain

Tohru Shimizu; Kaori Ohtani; Hideki Hirakawa; Kenshiro Ohshima; Atsushi Yamashita; Tadayoshi Shiba; Naotake Ogasawara; Masahira Hattori; Satoru Kuhara; Hideo Hayashi

2002-01-01

74

Real-time multiplex PCR assays for reliable detection of Clostridium perfringens toxin genes in animal isolates.  

PubMed

Typing of Clostridium perfringens strains by PCR-based determination of toxin genes proved to be a reliable method for diagnosis of enterotoxaemia in various animal species. We report the establishment and validation of three real-time fluorogenic (TaqMan) multiplex PCRs for the detection of C. perfringens alpha-, beta-, beta2-, epsilon-, entero- and iota-toxin genes. The composition of the PCRs was chosen with regard to robustness of the assays and in order to increase sensitivity compared to the conventional simplex PCRs. The combination of probe dyes selected for the real-time assays (FAM/TAMRA, Cy-5/BHQ-2 and VIC/TAMRA) as well as the designation of the chromosome-borne alpha-toxin as internal positive control allowed the creation of highly specific and sensitive, as well as time and cost effective PCRs. One hundred and three strains of C. perfringens isolated in Switzerland derived from clinical or suspected cases of enterotoxaemia in 10 different animal species were tested. The toxin genotypes were in agreement in both the conventional PCRs and the newly designed multiplex PCRs. Furthermore, the real-time PCR carried out as simplex allows to quantitate the copy numbers of plasmid-borne toxin genes in relation to the chromosomally located alpha-toxin gene. PMID:17855025

Albini, S; Brodard, I; Jaussi, A; Wollschlaeger, N; Frey, J; Miserez, R; Abril, C

2007-07-27

75

Comparison of methods for the enumeration of Clostridium perfringens spores in water.  

PubMed

Four methods for enumerating Clostridium perfringens spores in water were evaluated: (1) the IMM (Iron Milk Medium) method (MPN); (2) the LS (Lactose Sulfite Broth) method (MPN); (3) the m-CP (membrane filtration Clostridium perfringens Agar) method (membrane filtration); and (4) the TSC (Tryptose Sulfite Cycloserine Agar) method (membrane filtration). The performance of these methods was compared with that of the DRCM (Differential Reinforced Clostridium Medium) method (MPN) as adopted by CETESB (Brazil's Environmental Sanitation Technology Company) for the analysis of C. perfringens spores in water. Statistical analysis was performed according to ISO 17994:2004 (Water Quality - Criteria for Establishing Equivalence between Microbiological Methods). The LS, m-CP, and TSC methods were considered not equivalent to the DRCM method, as they gave significantly lower results. The IMM showed inconclusive results and, according to ISO 17994:2004, analysis of a greater number of samples is needed to draw definitive conclusions comparing IMM and DRCM. PMID:22233899

Junqueira, Valéria Christina Amstalden; Neto, Romeu Cantúsio; da Silva, Neusely; Terra, Juliana Hirata

2012-01-01

76

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

PubMed Central

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.

Salvarani, Felipe Masiero; Silveira Silva, Rodrigo Otavio; Pires, Prhiscylla Sadana; da Costa Cruz Junior, Eduardo Coulaud; Albefaro, Isabella Silva; de Carvalho Guedes, Roberto Mauricio; Faria Lobato, Francisco Carlos

2012-01-01

77

A middle-aged lady with a pyogenic liver abscess caused by Clostridium perfringens  

PubMed Central

The pyogenic liver abscess caused by Clostridium perfringens (C. perfringens) is a rare, but rapidly fatal infection. It is usually associated with malignancy and immunosuppression. We report the case of 50-year-old lady with the secondary liver metastases from rectal cancer presented with fever and epigastric pain. The identification of Gram-positive bacilli septicaemia, the presence of gas-forming liver abscess and massive intravascular hemolysis should lead to the suspicion of C. perfringens infection. Here we review twenty cases published since 1990 and their clinical features are discussed. The importance of ”an aggressive treatment policy” with multidisciplinary team approach is emphasized.

Law, Siu-Tong; Lee, Ming Kai

2012-01-01

78

Sporulation and Enterotoxin Production by Mutants of Clostridium perfringens  

PubMed Central

The ability of Clostridium perfringens type A to produce an enterotoxin active in human food poisoning has been shown to be directly related to the ability of the organism to sporulate. Enterotoxin was produced only in a sporulation medium and not in a growth medium in which sporulation was repressed. Mutants with an altered ability to sporulate were isolated from an sp+ ent+ strain either as spontaneous mutants or after mutagenesis with acridine orange or nitrosoguanidine. All sp0? mutants were ent?. Except for one isolate, these mutants were not disturbed in other toxic functions characteristic of the wild type and unrelated to sporulation. A total of four of seven osp0 mutants retained the ability to produce detectable levels of enterotoxin. None of the ent? mutants produced gene products serologically homologous to enterotoxin. A total of three sp? mutants, blocked at intermediate stages of sporulation, produced enterotoxin. Of these mutants, one was blocked at stage III, one probably at late stage IV, and one probably at stage V. A total of three sp+ revertants isolated from an sp? ent? mutant regained not only the ability to sporulate but also the ability to produce enterotoxin. The enterotoxin appears to be a sporulation-specific gene product; however, the function of the enterotoxin in sporulation is unknown. Images

Duncan, Charles L.; Strong, Dorothy H.; Sebald, Madeleine

1972-01-01

79

Clostridium perfringens Enterotoxin Interacts with Claudins via Electrostatic Attraction*  

PubMed Central

Clostridium perfringens enterotoxin (CPE), a causative agent of food poisoning, is a pore-forming toxin disrupting the selective permeability of the plasma membrane of target cells, resulting in cell death. We previously identified claudin as the cell surface receptor for CPE. Claudin, a component of tight junctions, is a tetratransmembrane protein and constitutes a large family of more than 20 members, not all of which serve as the receptor for CPE. The mechanism by which the toxin distinguishes the sensitive claudins is unknown. In this study, we localized the region of claudin responsible for interaction with CPE to the C-terminal part of the second extracellular loop and found that the isoelectric point of this region in sensitive claudins was higher than insensitive claudins. Amino acid substitutions to lower the pI resulted in reduced sensitivity to CPE among sensitive claudins, whereas substitutions to raise the pI endowed CPE-insensitive claudins with sensitivity. The steric structure of the claudin-binding domain of CPE reveals an acidic cleft surrounded by Tyr306, Tyr310, Tyr312, and Leu315, which were reported to be essential for interaction with the sensitive claudins. These results imply that an electrostatic attraction between the basic claudin region and the acidic CPE cleft is involved in their interaction.

Kimura, Jun; Abe, Hiroyuki; Kamitani, Shigeki; Toshima, Hirono; Fukui, Aya; Miyake, Masami; Kamata, Yoichi; Sugita-Konishi, Yoshiko; Yamamoto, Shigeki; Horiguchi, Yasuhiko

2010-01-01

80

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

PubMed Central

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.

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

2012-01-01

81

Characterization of an ATP-binding cassette from Clostridium perfringens with homology to an ABC transporter from Clostridium hathewayi  

Microsoft Academic Search

A ciprofloxacin-resistant mutant of Clostridium perfringens, strain VPI-C, which had stable mutations in the topoisomerase genes, accumulated less norfloxacin and ethidium bromide than the wild type, strain VPI. Efflux pump inhibitors both increased the accumulation of ethidium bromide by cells of the mutant and enhanced their sensitivity to this toxic dye. Cloning a gene, which codes for a putative ABC

Fatemeh Rafii; Robert J. Carman

2009-01-01

82

In-vitro antimicrobial susceptibility of Clostridium perfringens from commercial turkey and broiler chicken origin  

Microsoft Academic Search

The minimum inhibitory concentrations (MIC) of eight antibiotics and two anticoccidial agents were determined for Clostridium perfringens strains isolated from 26 commercial broiler farms and 22 commercial turkey farms. Isolates were obtained from the intestines of birds on the farm or at the processing plant using standard culture and identification techniques. The microbroth dilution test was used to determine the

K. L. Watkins; T. R. Shryock; R. N. Dearth; Y. M. Saif

1997-01-01

83

CHITOSAN PROTECTS COOKED GROUND BEEF AND TURKEY AGAINST CLOSTRIDIUM PERFRINGENS SPORES DURING CHILLING  

Technology Transfer Automated Retrieval System (TEKTRAN)

We investigated the inhibition of Clostridium perfringens spore germination and outgrowth by the biopolymer chitosan during abusive chilling of cooked ground beef (25% fat) and turkey (7% fat) obtained from a retail store. Chitosan was mixed into the thawed beef or turkey at concentrations of 0.5, ...

84

Control of Clostridium perfringens spores by plant-derived antimicrobials during cooling of cooked ground beef  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of Clostridium perfringens spore germination and outgrowth by carvacrol, cinnamaldehyde, thymol, oregano oil and two green tea extracts with low (green tea leaf powder (GTL); 141 mg of total catechins/g of green tea extract) and high (green tea leaf extract (GTE); 697 mg of total catechin...

85

Susceptibility of Escherichia coli, Salmonella sp. and Clostridium perfringens to organic acids and monolaurin  

Microsoft Academic Search

The antimicrobial activity of fatty acids, monolaurin, citric, succinic, fumaric, malic and lactic acid was determined in cultures of two strains of Escherichia coli, three strains of Salmonella sp. and two strains of Clostridium perfringens. Antimicrobial activity was expressed as minimum inhibitory concentration (MIC) that prevented growth and glucose utilization in treated cultures. Caprylic acid was the only acid inhibiting

E. SKRIVANOVA; M. MAROUNEK; V. BENDA; P. BREZINA

86

Sepsis due to Clostridium perfringens after Pregnancy Termination with Feticide by Cordocentesis: A Case Report  

Microsoft Academic Search

We report a case of sepsis due to Clostridium perfringens after termination of pregnancy at 22 weeks with feticide by cordocentesis. Three weeks earlier, the 41-year-old patient had undergone an amniocentesis and a full trisomy 13 karyotype had been discovered. Feticide was performed by injection of thiopental and potassium chloride after percutaneous umbilical foetal blood sampling through the same needle.

S. V. Li Kim Mui; Y. Chitrit; M. C. Boulanger; L. Maisonneuve; L. Choudat; P. de Bièvre

2002-01-01

87

Freshwater Suspended Sediments and Sewage Are Reservoirs for Enterotoxin-Positive Clostridium perfringens?  

PubMed Central

The release of fecal pollution into surface waters may create environmental reservoirs of feces-derived microorganisms, including pathogens. Clostridium perfringens is a commonly used fecal indicator that represents a human pathogen. The pathogenicity of this bacterium is associated with its expression of multiple toxins; however, the prevalence of C. perfringens with various toxin genes in aquatic environments is not well characterized. In this study, C. perfringens spores were used to measure the distribution of fecal pollution associated with suspended sediments in the nearshore waters of Lake Michigan. Particle-associated C. perfringens levels were greatest adjacent to the Milwaukee harbor and diminished in the nearshore waters. Species-specific PCR and toxin gene profiles identified 174 isolates collected from the suspended sediments, surface water, and sewage influent as C. perfringens type A. Regardless of the isolation source, the beta2 and enterotoxin genes were common among isolates. The suspended sediments yielded the highest frequency of cpe-carrying C. perfringens (61%) compared to sewage (38%). Gene arrangement of enterotoxin was investigated using PCR to target known insertion sequences associated with this gene. Amplification products were detected in only 9 of 90 strains, which suggests there is greater variability in cpe gene arrangement than previously described. This work presents evidence that freshwater suspended sediments and sewage influent are reservoirs for potentially pathogenic cpe-carrying C. perfringens spores.

Mueller-Spitz, Sabrina R.; Stewart, Lisa B.; Klump, J. Val; McLellan, Sandra L.

2010-01-01

88

Freshwater suspended sediments and sewage are reservoirs for enterotoxin-positive Clostridium perfringens.  

PubMed

The release of fecal pollution into surface waters may create environmental reservoirs of feces-derived microorganisms, including pathogens. Clostridium perfringens is a commonly used fecal indicator that represents a human pathogen. The pathogenicity of this bacterium is associated with its expression of multiple toxins; however, the prevalence of C. perfringens with various toxin genes in aquatic environments is not well characterized. In this study, C. perfringens spores were used to measure the distribution of fecal pollution associated with suspended sediments in the nearshore waters of Lake Michigan. Particle-associated C. perfringens levels were greatest adjacent to the Milwaukee harbor and diminished in the nearshore waters. Species-specific PCR and toxin gene profiles identified 174 isolates collected from the suspended sediments, surface water, and sewage influent as C. perfringens type A. Regardless of the isolation source, the beta2 and enterotoxin genes were common among isolates. The suspended sediments yielded the highest frequency of cpe-carrying C. perfringens (61%) compared to sewage (38%). Gene arrangement of enterotoxin was investigated using PCR to target known insertion sequences associated with this gene. Amplification products were detected in only 9 of 90 strains, which suggests there is greater variability in cpe gene arrangement than previously described. This work presents evidence that freshwater suspended sediments and sewage influent are reservoirs for potentially pathogenic cpe-carrying C. perfringens spores. PMID:20581181

Mueller-Spitz, Sabrina R; Stewart, Lisa B; Klump, J Val; McLellan, Sandra L

2010-06-25

89

Predictive model for growth of Clostridium perfringens at temperatures applicable to cooling of cooked uncured beef and chicken  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this investigation was to develop and validate a model for predicting the relative growth of Clostridium perfringens from spore inocula in uncured chicken and beef meat during cooling. Isothermal growth curves of C. perfringens at various temperatures from 10-48.9C were evaluated, ...

90

Roles of DacB and Spm Proteins in Clostridium perfringens Spore Resistance to Moist Heat, Chemicals, and UV Radiation  

Microsoft Academic Search

Clostridium perfringens food poisoning is caused mainly by enterotoxigenic type A isolates that typically possess high spore heat resistance. Previous studies have shown that \\/-type small, acid-soluble proteins (SASP) play a major role in the resistance of Bacillus subtilis and C. perfringens spores to moist heat, UV radiation, and some chemicals. Additional major factors in B. subtilis spore resistance are

Daniel Paredes-Sabja; Nahid Sarker; Barbara Setlow; Peter Setlow; Mahfuzur R. Sarker

91

Inhibition of Clostridium perfringens by a Novel Strain of Bacillus subtilis Isolated from the Gastrointestinal Tracts of Healthy Chickens  

Microsoft Academic Search

The objectives of this study were to isolate beneficial strains of microorganisms from the gastrointestinal tracts of healthy chickens and to screen them against Clostridium perfringens, a causative agent of necrotic enteritis in poultry. One of the bacteria isolated, a strain of Bacillus subtilis, was found to possess an anticlostridial factor that could inhibit the C. perfringens ATCC 13124 used

Alex Yeow-Lim Teo; Hai-Meng Tan

2005-01-01

92

Antimicrobial susceptibility of Swedish, Norwegian and Danish isolates of Clostridium perfringens from poultry, and distribution of tetracycline resistance genes  

Microsoft Academic Search

This study was undertaken to determine the in vitro susceptibility of Clostridium perfringens, isolated from poultry to antimicrobials used in poultry production. The minimal inhibitory concentration (MIC) of eight antimicrobials, including the ionophoric coccidiostat narasin, was determined for 102 C. perfringens isolates, 58 from Sweden, 24 from Norway and 20 from Denmark. Susceptibility to each antimicrobial compound was determined by

A Johansson; C Greko; B. E Engström; M Karlsson

2004-01-01

93

GROWTH OF CLOSTRIDIUM PERFRINGENS FROM SPORE INOCULA AT TEMPERATURES APPLICABLE TO COOLING OF COOKED MEAT AND POULTRY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of the germination and outgrowth of Clostridium perfringens by chitosan during the abusive chilling of beef and turkey was evaluated. Chilling of cooked beef and turkey from 54.4 to 7.2 degrees C resulted in C. perfringens population increases of > 5 log10 cfu/g during 18 h exponential...

94

Transcriptional analysis of the beta-galactosidase gene (pbg) in Clostridium perfringens.  

PubMed

The mode of expression of the beta-galactosidase gene (pbg) of Clostridium perfringens was examined. The pbg gene was transcribed on a single 3.7-kb mRNA. The transcript contained a message for ORF54, located upstream of the pbg gene in the chromosome, indicating that ORF54 and the pbg gene comprise one operon (pbg operon). Expression of the pbg operon was induced by lactose at the transcriptional level. The promoter structure of the pbg operon was characterized by many palindrome structures and direct repeats, which suggests that there might be some catabolite regulation of the expression of the pbg operon in C. perfringens. PMID:8566714

Kobayashi, T; Shimizu, T; Hayashi, H

1995-11-01

95

Optimized necrotic enteritis model producing clinical and subclinical infection of Clostridium perfringens in broiler chickens.  

PubMed

In this study we assessed the roles of Eimeria infection and dietary manipulation (feeding a diet with a high level of fishmeal) in an Australian necrotic enteritis (NE) challenge model in broiler chickens. An experiment was designed to test the hypothesis that Eimeria infection and dietary manipulation, i.e., inclusion of fishmeal in the diet, are necessary to induce NE experimentally. The results showed that the combination of Eimeria administration and fishmeal feeding had a significant effect on induction of clinical and subclinical Clostridium perfringens infection. The majority of the mortality that occurred during the second week of the trial was due to an NE outbreak following the C. perfringens challenge. The mortality rate of the birds was 12.00% for the high-fishmeal (HFM; 500 g/kg) group and 9.33% for the low-fishmeal (LFM; 250 g/kg) group when the birds were subjected to C. perfringens and Eimeria. Fishmeal alone did not induce significant mortality in birds challenged only with C. perfringens but showed a significantly higher C. perfringens count than the non-fishmeal (NFM) control group. Eimeria administration had a significant effect on NE-related mortality but did not have an effect on the C. perfringens count. In accordance with the time course of bird mortality, it can be determined that of the 3 successive days of oral gavage with C. perfringens, the first inoculation was essential for inducing NE, but the third had no additional effect on NE-related mortality. Also, reducing the fishmeal level from 500 to 250 g/kg had no negative impact on the reproducibility of the model. It may be concluded that NE can be consistently induced under experimental conditions by feeding broilers a diet containing 250 g/kg fishmeal, using a single inoculation with low numbers of Eimeria, administering one or two oral C. perfringens inoculations, and maintaining appropriate ambient temperatures and diets. PMID:20945788

Wu, Shu-Biao; Rodgers, Nicholas; Choct, Mingan

2010-09-01

96

CodY Is a Global Regulator of Virulence-Associated Properties for Clostridium perfringens Type D Strain CN3718  

PubMed Central

ABSTRACT CodY is known to regulate various virulence properties in several Gram-positive bacteria but has not yet been studied in the important histotoxic and intestinal pathogen Clostridium perfringens. The present study prepared an isogenic codY-null mutant in C. perfringens type D strain CN3718 by insertional mutagenesis using the Targetron system. Western blot analysis indicated that, relative to wild-type CN3718 or a complementing strain, this isogenic codY mutant produces reduced levels of epsilon toxin (ETX). Using supernatants from cultures of the wild-type, codY-null mutant, and complementing strains, CodY regulation of ETX production was shown to have cytotoxic consequences for MDCK cells. The CodY regulatory effect on ETX production was specific, since the codY-null mutant still made wild-type levels of alpha-toxin and perfringolysin O. Sialidase activity measurements and sialidase Western blot analysis of supernatants from CN3718 and its isogenic derivatives showed that CodY represses overall exosialidase activity due to a reduced presence of NanH in culture supernatants. Inactivation of the codY gene significantly decreased the adherence of CN3718 vegetative cells or spores to host Caco-2 cells. Finally, the codY mutant showed increased spore formation under vegetative growth conditions, although germination of these spores was impaired. Overall, these results identify CodY as a global regulator of many C. perfringens virulence-associated properties. Furthermore, they establish that, via CodY, CN3718 coordinately regulates many virulence-associated properties likely needed for intestinal infection.

Li, Jihong; Ma, Menglin; Sarker, Mahfuzur R.; McClane, Bruce A.

2013-01-01

97

Spoilage of an acid food product by Clostridium perfringens, C. barati and C. butyricum.  

PubMed

Spoilage of canned pasteurized brined mung bean sprouts, acidified with citric acid to pH 4.0-4.5, was found to be caused by acid tolerant Clostridium spp. including the species barati, perfringens and butyricum. The pH limit for growth in the brine used were estimated 3.7, 3.7 and 4.0 respectively. Some of the isolated C. perfringens strains produced enterotoxins in sporulation media. The spores of the isolated anaerobes appeared to originate from mung beans, but C. barati and C. perfringens strains freshly isolated from dry beans, were unable to grow in acidified brine. During germination and sprouting of mung beans, the oxygen concentration decreased, while carbon dioxide concentration increased considerably, due to respiration of the sprouts and actively growing Enterobacteriaceae and lactobacilli. It was assumed that this allowed C. barati and C. perfringens strains to grow and acquire the observed unusual acid tolerance. After increasing aerobicity during sprouting, no growth of Clostridium spp. was observed, substantiating the assumption. PMID:2561952

de Jong, J

1989-05-01

98

Binding and Internalization of Clostridium perfringens Iota-Toxin in Lipid Rafts  

Microsoft Academic Search

Clostridium perfringens iota-toxin is a binary toxin composed of an enzymatic component (Ia) and a binding component (Ib). The oligomer of Ib formed in membranes induces endocytosis. We examined the binding and internalization of Ib by using Cy3-labeled Ib. Labeled Ib was retained at the membranes of MDCK cells for 60 min of incubation at 37°C, and later it was

Masahiro Nagahama; Akiwo Yamaguchi; Tohko Hagiyama; Noriko Ohkubo; Keiko Kobayashi; Jun Sakurai

2004-01-01

99

Substitutions of amino acids in ?-helix-4 of gyrase A confer fluoroquinolone resistance on Clostridium perfringens  

Microsoft Academic Search

DNA gyrase, an essential enzyme that regulates DNA topology in bacteria, is the target of fluoroquinolones. Three fluoroquinolone-resistant\\u000a mutants derived from one strain of Clostridium perfringens had amino acid substitutions of glycine 81 to cysteine, aspartic acid 87 to tyrosine, or both, in ?-helix-4 of gyrase A.\\u000a The gyrase mutations affected the growth kinetics of mutants differently when the mutants

Fatemeh Rafii

2007-01-01

100

Coccidia-induced mucogenesis promotes the onset of necrotic enteritis by supporting Clostridium perfringens growth  

Microsoft Academic Search

This study tested the hypothesis that a host mucogenic response to an intestinal coccidial infection promotes the onset of necrotic enteritis (NE). A chick NE model was used in which birds were inoculated with Eimeria acervulina and E. maxima and subsequently with Clostridium perfringens (EAM\\/CP). A second group of EAM\\/CP-infected birds was treated with the ionophore narasin (NAR\\/EAM\\/CP). These groups

C. T. Collier; C. L. Hofacre; A. M. Payne; D. B. Anderson; P. Kaiser; R. I. Mackie; H. R. Gaskins

2008-01-01

101

In Vivo Studies of Clostridium perfringens in Mouse Gas Gangrene Model  

Microsoft Academic Search

Understanding the pathogenesis of infectious diseases requires comprehensive knowledge of the proteins expressed by the pathogen\\u000a during in vivo growth in the host. Proteomics provides the tools for such analyses but the protocols required to purify sufficient\\u000a quantities of the pathogen from the host organism are currently lacking. In this study, we have separated Clostridium perfringens, a highly virulent bacterium

Nabonita Sengupta; Syed Imteyaz Alam

2011-01-01

102

Evidence that Membrane Rafts Are Not Required for the Action of Clostridium perfringens Enterotoxin  

Microsoft Academic Search

The action of bacterial pore-forming toxins typically involves membrane rafts for binding, oligomerization, and\\/or cytotoxicity. Clostridium perfringens enterotoxin (CPE) is a pore-forming toxin with a unique, multistep mechanism of action that involves the formation of complexes containing tight junction proteins that include claudins and, sometimes, occludin. Using sucrose density gradient centrifugation, this study evaluated whether the CPE complexes reside in

Justin A. Caserta; Martha L. Hale; Michel R. Popoff; Bradley G. Stiles; Bruce A. McClane

2008-01-01

103

Complete genome sequence of Clostridium perfringens, an anaerobic flesh-eater  

PubMed Central

Clostridium perfringens is a Gram-positive anaerobic spore-forming bacterium that causes life-threatening gas gangrene and mild enterotoxaemia in humans, although it colonizes as normal intestinal flora of humans and animals. The organism is known to produce a variety of toxins and enzymes that are responsible for the severe myonecrotic lesions. Here we report the complete 3,031,430-bp sequence of C. perfringens strain 13 that comprises 2,660 protein coding regions and 10 rRNA genes, showing pronounced low overall G + C content (28.6%). The genome contains typical anaerobic fermentation enzymes leading to gas production but no enzymes for the tricarboxylic acid cycle or respiratory chain. Various saccharolytic enzymes were found, but many enzymes for amino acid biosynthesis were lacking in the genome. Twenty genes were newly identified as putative virulence factors of C. perfringens, and we found a total of five hyaluronidase genes that will also contribute to virulence. The genome analysis also proved an efficient method for finding four members of the two-component VirR/VirS regulon that coordinately regulates the pathogenicity of C. perfringens. Clearly, C. perfringens obtains various essential materials from the host by producing several degradative enzymes and toxins, resulting in massive destruction of the host tissues.

Shimizu, Tohru; Ohtani, Kaori; Hirakawa, Hideki; Ohshima, Kenshiro; Yamashita, Atsushi; Shiba, Tadayoshi; Ogasawara, Naotake; Hattori, Masahira; Kuhara, Satoru; Hayashi, Hideo

2002-01-01

104

New medium for rapid screening and enumeration of Clostridium perfringens in foods.  

PubMed Central

A rapid and sensitive procedure for estimating low numbers of Clostridium perfringens has been investigated and compared to methods used currently in the food industry. The new liquid medium, RPM (rapid perfringens medium), was compared with sulfite-polymyxin-sulfadiazine agar and tryptose-sulfite-cycloserine agar in recovery studies with naturally contaminated and with inoculated foods. The medium consists of a mixture of litmus milk and fluid thioglycolate medium fortified with glucose, peptone, gelatin, yeast extract, sodium chloride, and ferrous sulfate. Selectivity is based on an antibiotic system (polymyxin B sulfate and neomycin sulfate) incorporated into the medium, coupled with an incubation temprature of 46 to 48 degrees C for 24 h. Tubes were scored as positive if a stormy fermentation was observed. All tubes demonstrating stormy fermentation were confirmed as containing C. perfringens. Of a total of 774 naturally contaminated food samples, 546 samples (71%) were found to contain C. perfringens with RPM, whereas only 168 (22%) of the samples were positive using sulfite-polymyxin-sulfadiazine agar. C. perfringens was isolated from 71% of 85 other samples using RPM as compared to 14% with tryptose-sulfite-cycloserine agar. Enumeration studies on 14 individual samples using the most probable number technique also demonstrated greater sensitivity with RPM.

Erickson, J E; Deibel, R H

1978-01-01

105

Fatal foodborne Clostridium perfringens illness at a state psychiatric hospital--Louisiana, 2010.  

PubMed

Clostridium perfringens, the third most common cause of foodborne illness in the United States (1), most often causes a self-limited, diarrheal disease lasting 12-24 hours. Fatalities are very rare, occurring in <0.03% of cases (1). Death usually is caused by dehydration and occurs among the very young, the very old, and persons debilitated by illness (2). On May 7, 2010, 42 residents and 12 staff members at a Louisiana state psychiatric hospital experienced vomiting, abdominal cramps, and diarrhea. Within 24 hours, three patients had died. The three fatalities occurred among patients aged 41-61 years who were receiving medications that had anti-intestinal motility side effects. For two of three decedents, the cause of death found on postmortem examination was necrotizing colitis. Investigation by the Louisiana Office of Public Health (OPH) and CDC found that eating chicken served at dinner on May 6 was associated with illness. The chicken was cooked approximately 24 hours before serving and not cooled in accordance with hospital guidelines. C. perfringens enterotoxin (CPE) was detected in 20 of 23 stool specimens from ill residents and staff members. Genetic testing of C. perfringens toxins isolated from chicken and stool specimens was carried out to determine which of the two strains responsible for C. perfringens foodborne illness was present. The specimens tested negative for the beta-toxin gene, excluding C. perfringens type C as the etiologic agent and implicating C. perfringens type A. This outbreak underscores the need for strict food preparation guidelines at psychiatric inpatient facilities and the potential risk for adverse outcomes among any patients with impaired intestinal motility caused by medications, disease, and extremes of age when exposed to C. perfringens enterotoxin. PMID:22895383

2012-08-17

106

Coccidia-induced mucogenesis promotes the onset of necrotic enteritis by supporting Clostridium perfringens growth.  

PubMed

This study tested the hypothesis that a host mucogenic response to an intestinal coccidial infection promotes the onset of necrotic enteritis (NE). A chick NE model was used in which birds were inoculated with Eimeria acervulina and E. maxima and subsequently with Clostridium perfringens (EAM/CP). A second group of EAM/CP-infected birds was treated with the ionophore narasin (NAR/EAM/CP). These groups were compared to birds that were either non-infected (NIF), or infected only with E. acervulina and E. maxima (EAM), or C. perfringens (CP). The impact of intestinal coccidial infection and anti-coccidial treatment on host immune responses and microbial community structure were evaluated with histochemical-, cultivation- and molecular-based techniques. Barrier function was compromised in EAM/CP-infected birds as indicated by elevated CFUs for anaerobic bacteria and C. perfringens in the spleen when compared to NIF controls at day 20, with a subsequent increase in intestinal NE lesions and mortality at day 22. These results correlate positively with a host inflammatory response as evidenced by increased ileal interleukin (IL)-4, IL-10 and IFN-gamma RNA expression. Concurrent increases in chicken intestinal mucin RNA expression, and goblet cell number and theca size indicate that EAM/CP induced an intestinal mucogenic response. Correspondingly, the growth of mucolytic bacteria and C. perfringens as well as alpha toxin production was greatest in EAM/CP-infected birds. The ionophore narasin, which directly eliminates coccidia, reduced goblet cell theca size, IL-10 and IFN-gamma expression, the growth of mucolytic bacteria including C. perfringens, coccidial and NE lesions and mortality in birds that were co-infected with coccidia and C. perfringens. Collectively the data support the hypothesis that coccidial infection induces a host mucogenic response providing a growth advantage to C. perfringens, the causative agent of NE. PMID:18068809

Collier, C T; Hofacre, C L; Payne, A M; Anderson, D B; Kaiser, P; Mackie, R I; Gaskins, H R

2007-12-19

107

Expression of a Clostridium perfringens type IV pilin by Neisseria gonorrhoeae mediates adherence to muscle cells.  

PubMed

Clostridium perfringens is an anaerobic, Gram-positive bacterium that causes a range of diseases in humans, including lethal gas gangrene. We have recently shown that strains of C. perfringens move across the surface of agar plates by a unique type IV pilus (TFP)-mediated social motility that had not been previously described. Based on sequence homology to pilins in Gram-negative bacteria, C. perfringens appears to have two pilin subunits, PilA1 and PilA2. Structural prediction analysis indicated PilA1 is similar to the pseudopilin found in Klebsiella oxytoca, while PilA2 is more similar to true pilins found in the Gram-negative pathogens Pseudomonas aeruginosa and Neisseria gonorrhoeae. Strains of N. gonorrhoeae that were genetically deficient in the native pilin, PilE, but supplemented with inducible expression of PilA1 and PilA2 of C. perfringens were constructed. Genetic competence, wild-type twitching motility, and attachment to human urogenital epithelial cells were not restored by expression of either pilin. However, attachment to mouse and rat myoblast (muscle) cell lines was observed with the N. gonorrhoeae strain expressing PilA2. Significantly, wild-type C. perfringens cells adhered to mouse myoblasts under anaerobic conditions, and adherence was 10-fold lower in a pilT mutant that lacked functional TFP. These findings implicate C. perfringens TFP in the ability of C. perfringens to adhere to and move along muscle fibers in vivo, which may provide a therapeutic approach to limiting this rapidly spreading and highly lethal infection. PMID:21646450

Rodgers, Katherine; Arvidson, Cindy Grove; Melville, Stephen

2011-06-06

108

Inactivation of Cryptosporidium parvum oocysts and Clostridium perfringens spores by a mixed-oxidant disinfectant and by free chlorine.  

PubMed

Cryptosporidium parvum oocysts and Clostridium perfringens spores are very resistant to chlorine and other drinking-water disinfectants. Clostridium perfringens spores have been suggested as a surrogate indicator of disinfectant activity against Cryptosporidium parvum and other hardy pathogens in water. In this study, an alternative disinfectant system consisting of an electrochemically produced mixed-oxidant solution (MIOX; LATA Inc.) was evaluated for inactivation of both Cryptosporidium parvum oocysts and Clostridium perfringens spores. The disinfection efficacy of the mixed-oxidant solution was compared to that of free chlorine on the basis of equal weight per volume concentrations of total oxidants. Batch inactivation experiments were done on purified oocysts and spores in buffered, oxidant demand-free water at pH 7 an 25 degrees C by using a disinfectant dose of 5 mg/liter and contact times of up to 24 h. The mixed-oxidant solution was considerably more effective than free chlorine in activating both microorganisms. A 5-mg/liter dose of mixed oxidants produced a > 3-log10-unit (> 99.9%) inactivation of Cryptosporidium parvum oocysts and Clostridium perfringens spores in 4 h. Free chlorine produce no measurable inactivation of Cryptosporidium parvum oocysts by 4 or 24 h, although Clostridium perfringens spores were inactivated by 1.4 log10 units after 4 h. The on-site generation of mixed oxidants may be a practical and cost-effective system of drinking water disinfection protecting against even the most resistant pathogens, including Cryptosporidium oocysts. PMID:9097455

Venczel, L V; Arrowood, M; Hurd, M; Sobsey, M D

1997-04-01

109

Clostridium perfringens growth from spore inocula in sous-vide processed pork-based Mexican entrée.  

PubMed

The combined effect of Citricidal wih irradiation on Clostridium perfringens growth from spores in a sous-vide processed marinated pork meat Mexican entrée was investigated. Citricidal was added at 200 or 800 ppm after mixing pork meat with tomatillo sauce and inoculated with 3 log(10) CFU/g of C. perfringens spores. Samples were irradiated at either 0 or 2 kGy, heated to an internal temperature of 71 degrees C, and stored at 4 degrees C for 28 d, 15 degrees C for 45 d, and 25 degrees C for 26 h. To simulate the conditions that may occur during transportation, distribution, storage, or handling in supermarkets or by consumers, the effect of static temperature abuse on C. perfringens growth was assessed by transferring samples stored at 4 to 25 degrees C for 13 and 15 h. Total C. perfringens populations were determined by plating diluted samples on tryptose-sulfite-cycloserine agar. Growth was not observed up to 45 d of storage at 15 degrees C in samples supplemented with 800 ppm of Citricidal. At 25 degrees C, no significant differences (P > 0.05) on the lag phase duration due to antimicrobial treatments was observed. The temperature abuse of refrigerated products for up to 15 h did not lead to C. perfringens growth to high infective dose levels of 1 million cells required to cause food poisoning. The results suggest that 800 ppm Citricidal can have significant bacteriostatic activity against C. perfringens and may provide a degree of protection against this pathogen in sous-vide processed marinated pork meat Mexican entrée, under mild temperature abuse (

Miguel-Garcia, Denise Y; Juneja, Vijay K; Valenzuela-Melendrez, Martin; Díaz-Cinco, Martha E; Thippareddi, H; Aida Peña-Ramos, E

110

Prevalence and characterization of Clostridium perfringens from the faecal microbiota of elderly Irish subjects.  

PubMed

The aim of this study was to investigate the diversity and composition of the intestinal microbiota of elderly subjects using a combination of culture-dependent techniques and 16S rRNA gene amplicon sequencing. The study was performed as part of the ELDERMET project, in which 368 faecal samples were assessed for viable numbers of Bifidobacterium spp., Lactobacillus spp. and Enterobacteriaceae on selective agar. However, the Bifidobacterium selective medium used also supported the growth of Clostridium perfringens, which appeared as distinct colonies and were subsequently characterized phenotypically and genotypically. All the isolates were confirmed as toxin biotype A producers. In addition, three isolates tested also had the genetic determinants for the ?2 toxin. Of the 368 faecal samples assessed, C. perfringens was detected in 28 samples (7.6%). Moreover, C. perfringens was observed in samples from subjects in all the residence locations assessed but was most prevalent in subjects from long-stay residential care, with 71.4% of the samples (63.2% of the subjects) being from this residence location, and with a shedding level in excess of 10(6) c.f.u. (g faeces)(-1). Microbiota profiling revealed some significant compositional changes across both the family and genus taxonomic levels between the C. perfringens-positive and -negative datasets. Levels of culturable Bifidobacterium spp. and Lactobacillus spp. were significantly (P<0.05) lower in the C. perfringens-positive samples. Sequence-based methods also confirmed a significant difference in the Bifidobacterium spp. level (P<0.05) between both datasets. Taken together, these data suggest that a high viable count [>10(6) c.f.u. (g faeces)(-1)] of C. perfringens in stool samples may be indicative of a less healthy microbiota in the intestine of elderly people in long-stay residential care. PMID:23222860

Lakshminarayanan, Bhuvaneswari; Harris, Hugh M B; Coakley, Mairéad; O'Sullivan, Orla; Stanton, Catherine; Pruteanu, Mihaela; Shanahan, Fergus; O'Toole, Paul W; Ross, R Paul

2012-12-06

111

An investigation into the association between cpb2-encoding Clostridium perfringens type A and diarrhea in neonatal piglets.  

PubMed

To investigate the possible role of cpb2-positive type A Clostridium perfringens in neonatal diarrheal illness in pigs, the jejunum and colon of matched normal and diarrheic piglets from 10 farms with a history of neonatal diarrhea were examined grossly and by histopathology, and tested for C. perfringens, for C. perfringens beta2 (CPB2) toxin, as well as for Clostridium difficile toxins, Salmonella, enterotoxigenic Escherichia coli, rotavirus, transmissible gastroenteritis (TGE) virus, and coccidia. Clostridium perfringens isolates were tested using a multiplex real-time polymerase chain reaction (PCR) to determine the presence of cpa, consensus and atypical cpb2, and other virulence-associated genes. The numbers of C. perfringens in the intestinal contents were lower in diarrheic piglets (log?? 5.4 CFU/g) compared with normal piglets (log?? 6.5 CFU/g) (P < 0.05). The consensus cpb2 was present in 93% of isolates in each group, but atypical cpb2 was less common (56% healthy, 32% diarrheic piglets isolates, respectively, P < 0.05). The presence of CPB2 toxin in the intestinal contents of normal and diarrheic piglets did not differ significantly. Clostridium difficile toxins and rotavirus were each detected in 7 of the 21 (33%) diarrheic piglets. Rotavirus, C. difficile toxins, Salmonella, or enterotoxigenic E. coli were concurrently recovered in different combinations in 4 diarrheic piglets. The cause of diarrhea in 8 of the 21 (38%) piglets on 6 farms remained unknown. The etiological diagnosis of diarrhea could not be determined in any of the piglets on 2 of the farms. This study demonstrated that the number of cpb2-positive type A C. perfringens in the intestinal contents was not a useful approach for making a diagnosis of type A C. perfringens enteritis in piglets. Further work is required to confirm whether cpb2-carrying type A C. perfringens have a pathogenic role in enteric infection in neonatal swine. PMID:23814355

Farzan, Abdolvahab; Kircanski, Jasmina; DeLay, Josepha; Soltes, Glenn; Songer, J Glenn; Friendship, Robert; Prescott, John F

2013-01-01

112

A recombinant carboxy-terminal domain of alpha-toxin protects mice against Clostridium perfringens.  

PubMed

Clostridium perfringens alpha-toxin (CP, 370 residues) is one of the main agents involved in the development of gas gangrene. In this study, the immunogenicity and protective efficacy of the C-terminal domain (CP251-370) of the toxin and phospholipase C (PLC; CB, 372 residues) of Clostridum bifermentans isolated from cases of clostridium necrosis were examined. The recombinant proteins were expressed as glutathione S-transferase (GST) fusion proteins. Antibodies that cross-reacted with alpha-toxin were produced after immunization with recombinant proteins including GST-CP251-370, GST-CP281-370, GST-CP311-370, CB1-372 and GST-CB251-372. Anti-GST-CP251-370, anti-GST-CP281-370 and anti-GST-CP311-370 sera neutralized both the PLC and hemolytic activities of alpha-toxin, whereas anti-CB1-372 and anti-GST-CB251-372 weakly neutralized these activities. Immunization with GST-CP251-370 and GST-CP281-370 provided protection against the lethal effects of the toxin and C. perfringens type A NCTC8237. Partial protection from the toxin and C. perfringens was elicited by immunization with GST-CP311-370 and CB1-372. GST-CP251-370 and GST-CP281-370 are promising candidates for vaccines for clostridial-induced gas gangrene. PMID:23668605

Nagahama, Masahiro; Oda, Masataka; Kobayashi, Keiko; Ochi, Sadayuki; Takagishi, Teruhisa; Shibutani, Masahiro; Sakurai, Jun

2013-05-01

113

Immunization of Broiler Chickens against Clostridium perfringens-Induced Necrotic Enteritis?  

PubMed Central

Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens. Currently, no vaccine against NE is available and immunity to NE is not well characterized. Our previous studies showed that immunity to NE followed oral infection by virulent rather than avirulent C. perfringens strains and identified immunogenic secreted proteins apparently uniquely produced by virulent C. perfringens isolates. These proteins were alpha-toxin, glyceraldehyde-3-phosphate dehydrogenase, pyruvate:ferredoxin oxidoreductase (PFOR), fructose 1,6-biphosphate aldolase, and a hypothetical protein (HP). The current study investigated the role of each of these proteins in conferring protection to broiler chickens against oral infection challenges of different severities with virulent C. perfringens. The genes encoding these proteins were cloned and purified as histidine-tagged recombinant proteins from Escherichia coli and were used to immunize broiler chickens intramuscularly. Serum and intestinal antibody responses were assessed by enzyme-linked immunosorbent assay. All proteins significantly protected broiler chickens against a relatively mild challenge. In addition, immunization with alpha-toxin, HP, and PFOR also offered significant protection against a more severe challenge. When the birds were primed with alpha-toxoid and boosted with active toxin, birds immunized with alpha-toxin were provided with the greatest protection against a severe challenge. The serum and intestinal washings from protected birds had high antigen-specific antibody titers. Thus, we conclude that there are certain secreted proteins, in addition to alpha-toxin, that are involved in immunity to NE in broiler chickens.

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

2007-01-01

114

In vitro susceptibility of Clostridium perfringens isolated from farm animals to growth-enhancing antibiotics.  

PubMed

Minimal inhibitory concentration (MIC) determinations were carried out with seven growth-enhancing antibiotics against 95 Clostridium perfringens field isolates obtained during 1991 and 1992 from poultry, pigs and calves. All were resistant to 64 micrograms ml-1 of the bambermycin antibiotic, flavomycin (flavophospholipol) and susceptible to avoparcin (MIC90 0.25 micrograms ml-1), avilamycin (MIC90 0.5 micrograms ml-1) and salinomycin (MIC90 < or = 0.12 micrograms ml-1). Acquired resistance against bacitracin was detected in some isolates from poultry and bovines and resistance to tylosin and virginiamycin in some strains from all species investigated. Overall, the prevalence of resistance was comparable to the low levels recorded in 1979 in Cl. perfringens isolates from the same animal host species. PMID:8365955

Devriese, L A; Daube, G; Hommez, J; Haesebrouck, F

1993-07-01

115

Epidemiology of foodborne disease outbreaks caused by Clostridium perfringens, United States, 1998-2010.  

PubMed

Clostridium perfringens is estimated to be the second most common bacterial cause of foodborne illness in the United States, causing one million illnesses each year. Local, state, and territorial health departments voluntarily report C. perfringens outbreaks to the U.S. Centers for Disease Control and Prevention through the Foodborne Disease Outbreak Surveillance System. Our analysis included outbreaks confirmed by laboratory evidence during 1998-2010. A food item was implicated if C. perfringens was isolated from food or based on epidemiologic evidence. Implicated foods were classified into one of 17 standard food commodities when possible. From 1998 to 2010, 289 confirmed outbreaks of C. perfringens illness were reported with 15,208 illnesses, 83 hospitalizations, and eight deaths. The number of outbreaks reported each year ranged from 16 to 31 with no apparent trend over time. The annual number of outbreak-associated illnesses ranged from 359 to 2,173, and the median outbreak size was 24 illnesses. Outbreaks occurred year round, with the largest number in November and December. Restaurants (43%) were the most common setting of food preparation. Other settings included catering facility (19%), private home (16%), prison or jail (11%), and other (10%). Among the 144 (50%) outbreaks attributed to a single food commodity, beef was the most common commodity (66 outbreaks, 46%), followed by poultry (43 outbreaks, 30%), and pork (23 outbreaks, 16%). Meat and poultry outbreaks accounted for 92% of outbreaks with an identified single food commodity. Outbreaks caused by C. perfringens occur regularly, are often large, and can cause substantial morbidity yet are preventable if contamination of raw meat and poultry products is prevented at the farm or slaughterhouse or, after contamination, if these products are properly handled and prepared, particularly in restaurants and catering facilities. PMID:23379281

Grass, Julian E; Gould, L Hannah; Mahon, Barbara E

2013-02-04

116

Characterization of genes encoding for acquired bacitracin resistance in Clostridium perfringens.  

PubMed

Phenotypic bacitracin resistance has been reported in Clostridium perfringens. However, the genes responsible for the resistance have not yet been characterized. Ninety-nine C. perfringens isolates recovered from broilers and turkeys were tested for phenotypic bacitracin resistance. Bacitracin MIC(90) (>256 µg/ml) was identical for both turkey and chicken isolates; whereas MIC(50) was higher in turkey isolates (6 µg/ml) than in chicken isolates (3 µg/ml). Twenty-four of the 99 isolates showed high-level bacitracin resistance (MIC breakpoint >256 µg/ml) and the genes encoding for this resistance were characterized in C. perfringens c1261_A strain using primer walking. Sequence analysis and percentages of amino acid identity revealed putative genes encoding for both an ABC transporter and an overproduced undecaprenol kinase in C. perfringens c1261_A strain. These two mechanisms were shown to be both encoded by the putative bcrABD operon under the control of a regulatory gene, bcrR. Efflux pump inhibitor thioridazine was shown to increase significantly the susceptibility of strain c1261_A to bacitracin. Upstream and downstream from the bcr cluster was an IS1216-like element, which may play a role in the dissemination of this resistance determinant. Pulsed-field gel electrophoresis with prior double digestion with I-CeuI/MluI enzymes followed by hybridization analyses revealed that the bacitracin resistance genes bcrABDR were located on the chromosome. Semi-quantitative RT-PCR demonstrated that this gene cluster is expressed under bacitracin stress. Microarray analysis revealed the presence of these genes in all bacitracin resistant strains. This study reports the discovery of genes encoding for a putative ABC transporter and an overproduced undecaprenol kinase associated with high-level bacitracin resistance in C. perfringens isolates from turkeys and broiler chickens. PMID:22970221

Charlebois, Audrey; Jalbert, Louis-Alexandre; Harel, Josée; Masson, Luke; Archambault, Marie

2012-09-06

117

Genotyping of Clostridium perfringens isolated from domestic and exotic ruminants and swine.  

PubMed

Clostridium perfringens types A, B, C, D and E are known to cause severe enteritis/enterotoxaemia and diseases (especially caused by type A) belonging to the gas oedema complex in many species. Samples from the small intestine as well as faeces of domestic and exotic animals suffering from enterotoxaemic signs or having died within days after first occurance of toxaemia were submitted for typing C. perfringens toxovars by multiplex PCR. The following species have been investigated: domestic sheep (Ovis ammon; n = 10), domestic goat (Capra aegagrus hircus; n = 26), Japanese serow (Capricornis sumatraensis; n = 4), lechwe waterbuck (Hydrotragus leche; n = 1), blackbuck (Antilope cervicapra; n = 1), European reindeer (Rangifer tarandus tarandus; n = 4), domestic swine (Sus scrofa; n = 52), and collared peccary (Tayassu albirostris; n = 1). Interestingly, the predominant C. perfringens toxovar in domestic sheep was type A. This toxovar could also be diagnosed in all reindeer, in three Japanese serows, one lechwe waterbuck and most pigs (n = 47), the majority of those being at suckling age. Type D was the most prevalent toxovar (n = 18) in domestic goats, but also types A and E could be identified as pathogens in this species. Type C could only be found in domestic swine (n = 5) and in one case of clostridiosis in a Japanese serow. Two cases of enterotoxaemia in goats, one case in reindeer, and a single case in blackbuck and collared peccary were caused by C. perfringens type E. Genotyping of C. perfringens is recommended before starting vaccination programmes as it could be shown, that the importance of specific toxovars has been underestimated in specific species and/or age groups. PMID:14535937

Sipos, W; Fischer, L; Schindler, M; Schmoll, F

2003-09-01

118

Lyophilized Carnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged with Clostridium perfringens.  

PubMed

The present study aimed to investigate the effects of Carnobacterium divergens AS7 bacteriocin (divercin AS7) on growth performance, digestibility, fermentation processes, selected microbial populations, and histomorphology in broiler chickens challenged with a mixture of 3 Clostridium perfringens 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 challenged twice a day with the C. perfringens mixture. The C. perfringens challenge did not influence broiler BW gain but impaired feed conversion ratio from d 29 to 42 (P=0.023) and throughout the experimental period (P=0.038). Moreover, the C. perfringens challenge resulted in decreased pH levels of crop, gizzard, and ileum contents (P<0.05) and reduced the numbers of lactic acid bacteria in the ceca (P=0.01). Divercin supplementation decreased broiler feed intake from d 14 to 28 (P=0.001) but increased BW gain from d 29 to 42 (P=0.048). The divercin supplementation increased the AMEn level (P=0.015) and reduced digesta pH in crop and ileum (P=0.004 and P=0.042, respectively), but of nonchallenged birds only. Divercin supplementation, moreover, increased gizzard lactate concentrations (P=0.003). The crop concentrations of lactate and succinate and the ileum concentration of lactate were increased by divercin supplementation (P=0.005, P=0.027, and P=0.002, respectively) and C. perfringens challenge (P=0.034, P=0.053, and P=0.0002, respectively). Divercin supplementation decreased villus heights (P=0.0006) and crypt depths (P=0.044) in noninfected birds, whereas in challenged birds, villus heights (P<0.0001) were increased. In conclusion, the present study demonstrated a very complex response pattern of broilers exposed to C. perfringens challenge and dietary divercin AS7 supplementation, but it indicated that divercin AS7 may partly counterbalance the negative effects associated with C. perfringens. PMID:22802184

Józefiak, D; Sip, A; Rutkowski, A; Rawski, M; Kaczmarek, S; Wo?u?-Cholewa, M; Engberg, R M; Højberg, O

2012-08-01

119

Effects of Clostridium perfringens Alpha-Toxin (PLC) and Perfringolysin O (PFO) on Cytotoxicity to Macrophages, on Escape from the Phagosomes of Macrophages, and on Persistence of C. perfringens in Host Tissues  

Microsoft Academic Search

Clostridium perfringens is the most common cause of clostridial myonecrosis (gas gangrene). Polymorpho- nuclear cells (PMNs) appear to play only a minor role in preventing the onset of myonecrosis in a mouse animal model of the disease (unpublished results). However, the importance of macrophages in the host defense against C. perfringens infections is still unknown. Two membrane-active toxins produced by

David K. O'Brien; Stephen B. Melville

2004-01-01

120

ADP-ribosylation of actin from the green alga Chara corallina by Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin  

Microsoft Academic Search

Summary The ability of two bacterial toxins to modify a plant actin by covalent ADP-ribosylation was tested in the green algaChara corallina. Using [32P]NAD, bothClostridium botulinum C2 toxin andClostridium perfringens iota toxin labelled a protein of Mr 42 kDa which comigrated with actin and was immunoprecipitated by a monoclonal anti-actin antibody. ADP-ribosylation ofChara actin was more efficient with iota toxin

F. Grolig; I. Just; K. Aktories

1996-01-01

121

Clostridium perfringens type A and type A and ?2 toxin associated with enterotoxemia in a 5-week-old goat  

PubMed Central

Abstract Postmortem examination of a Boer buck kid that died peracutely revealed diffusely congested, edematous bowel. Clostridium perfringens Type A was isolated. Some isolates carried the gene for ?2 toxin, suggesting a role for ?2 toxin in caprine enterotoxemia, a common cause of death in growing kids.

2004-01-01

122

Necrotizing enterocolitis and death in a goat kid associated with enterotoxin (CPE)-producing Clostridium perfringens type A  

PubMed Central

A goat kid died after being depressed for several days. No significant gross abnormalities were observed at postmortem examination, while histopathological analysis revealed diffuse necrotizing enterocolitis. Isolation of Clostridium perfringens type A secreting enterotoxin (CPE) and presence of CPE in the small intestine suggest that CPE contributed to the death of this kid.

Fernandez Miyakawa, Mariano E.; Saputo, Julian; St. Leger, Judy; Puschner, Birgit; Fisher, Derek J.; McClane, Bruce A.; Uzal, Francisco A.

2007-01-01

123

CONTROL OF CLOSTRIDIUM PERFRINGENS GERMINATION AND OUTGROWTH BY BUFFERED SODIUM CITRATE DURING CHILLING OF ROAST BEEF AND INJECTED PORK.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of Clostridium perfringens germination and outgrowth by buffered sodium citrate and buffered sodium citrate supplemented with sodium diacetate was evaluated during abusive chilling of roast beef and injected pork. Beef top rounds and pork loins were injected with a brine containing NaCl (...

124

Control of Clostridium perfringens Spores by Green Tea Leaf Extracts During Cooling of Cooked Ground Beef, Chicken, and Pork  

Technology Transfer Automated Retrieval System (TEKTRAN)

We investigated the inhibition of Clostridium perfringens spore germination and outgrowth by two green tea extracts with low (GTL; 141 mg total catechins/g of green tea extract) and high (GTE; 697 mg total catechins/g of extract) catechin levels during abusive chilling of retail cooked ground beef, ...

125

AN EVALUATION OF ASCORBIC ACID AS A QUORUM SENSING ANALOGUE TO CONTROL GROWTH, SPORULATION, AND ENTEROTOXIN PRODUCTION IN CLOSTRIDIUM PERFRINGENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of quorum sensing by enterotoxin-producing strains of Clostridium perfringens was investigated. Autoinducer-2 (AI-2) activity was measured in the presence and absence of ascorbic acid (vitamin C; concentrations ranging from 10 to 300 mM), an AI-2 analogue. Subsequent effects on AI-2 pro...

126

CARVACROL, CINNAMALDEHYDE, OREGANO OIL, AND THYMOL INHIBIT CLOSTRIDIUM PERFRINGENS SPORE GERMINATION AND OUTGROWTH IN GROUND TURKEY DURING CHILLING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of Clostridium perfringens by plant-derived carvacrol, cinnamaldehyde, thymol, and oregano oil was evaluated during abusive chilling of cooked ground turkey (75% lean) obtained from a local grocery store. Test substances were mixed into thawed turkey product at concentrations of 0.1, 0.5...

127

In Vitro Activities of Daptomycin, Vancomycin, and Penicillin against Clostridium difficile, C. perfringens, Finegoldia magna, and Propionibacterium acnes  

Microsoft Academic Search

Daptomycin has in vitro activity against gram-positive anaerobic bacteria, although limited numbers of species have been tested. We studied the in vitro activities of daptomycin, vancomycin, and penicillin against more than 100 strains each of Clostridium difficile, C. perfringens, Finegoldia magna, and Propionibacterium acnes. Daptomycin Etest MICs and results from time-kill studies were determined for selected strains. For 392 of

Kerin L. Tyrrell; Diane M. Citron; Yumi A. Warren; Helen T. Fernandez; C. Vreni Merriam; Ellie J. C. Goldstein

2006-01-01

128

TRANSLOCATION OF CAMPYLOBACTER, SALMONELLA AND CLOSTRIDIUM PERFRINGENS TO SEVERAL LYMPHOID ORGANS FOLLOWING ORAL OR INTRACLOACAL INOCULATION OF BROILER CHICKS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Day old broiler chicks were either orally or intracloacally inoculated with a 100ul suspension containing 106-109 cells of one of three marker strains of either Campylobacter jejuni, Salmonella spp. or Clostridium perfringens. At one hour, one day and one week following inoculation, five birds from...

129

Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus--United States, 1998-2008.  

PubMed

From 1998 to 2008, 1229 foodborne outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus were reported in the United States; 39% were reported with a confirmed etiology. Vomiting was commonly reported in B. cereus (median, 75% of cases) and S. aureus outbreaks (median, 87%), but rarely in C. perfringens outbreaks (median, 9%). Meat or poultry dishes were commonly implicated in C. perfringens (63%) and S. aureus (55%) outbreaks, and rice dishes were commonly implicated in B. cereus outbreaks (50%). Errors in food processing and preparation were commonly reported (93%), regardless of etiology; contamination by a food worker was only common in S. aureus outbreaks (55%). Public health interventions should focus on these commonly reported errors to reduce the occurrence of outbreaks caused by B. cereus, C. perfringens, and S. aureus in the United States. PMID:23592829

Bennett, Sarah D; Walsh, Kelly A; Gould, L Hannah

2013-04-16

130

Impedance Analysis of Ovarian Cancer Cells upon Challenge with C-terminal Clostridium Perfringens Enterotoxin  

NASA Astrophysics Data System (ADS)

Both in vitro and animal studies in breast, prostate, and ovarian cancers have shown that clostridium perfringens enterotoxin (CPE), which binds to CLDN4, may have an important therapeutic benefit, as it is rapidly cytotoxic in tissues overexpressing CLDN4. This study sought to evaluate the ability of C-terminal clostridium perfringens enterotoxin (C-CPE), a CLDN4-targetting molecule, to disrupt tight junction barrier function. Electric cell-substrate impedance sensing (ECIS) was used to measure both junctional resistance and average cell-substrate separation of ovarian cancer cell lines after exposure to C-CPE. A total of 14 ovarian cancer cell lines were used, and included cell lines derived from serous, mucinous, and clear cells. Our results showed that junctional resistance increases as CLDN4 expression increases. In addition, C-CPE is non-cytotoxic in ovarian cancer cells expressing CLDN4. However, exposure to C-CPE results in a significant (p<0.05) dose- and CLDN4-dependent decrease in junctional resistance and an increase in cell-substrate separation. Treatment of ovarian cancer cell lines with C-CPE disrupts tight junction barrier function.

Gordon, Geoffrey; Lo, Chun-Min

2007-03-01

131

Levels and toxigenicity of Bacillus cereus and Clostridium perfringens from retail seafood.  

PubMed

For the period 1990 through 2003, seafood was the most commonly identified food linked to foodborne outbreaks in the United States. Fish as a commodity has rarely been examined for the presence of Bacillus cereus in particular. For the present study, 347 fresh and processed retail seafood samples were examined for the presence of Clostridium botulinum, Clostridium perfringens, and B. cereus. The presence of C. botulinum was not confirmed in any of the isolates, but C. perfringens was confirmed in 17 samples. One of the C. perfringens isolates possessed the enterotoxin gene, as determined by PCR. In contrast, 62 confirmed B. cereus isolates were obtained from separate samples at levels ranging from 3.6 to > 1,100 CFU/g. Thirty (48%) of 62 isolates produced both the hemolysin BL (HBL) and nonhemolytic (NHE) enterotoxins, and 58 (94%) and 31 (50%) produced NHE or HBL toxins, respectively. The presence of at least one of the three genes of the NHE complex was detected in 99% of the isolates; 69% of the isolates possessed all three genes. In contrast, 71% of the isolates possessed at least one of the three genes of the HBL complex, and 37% possessed all three HBL gene components. Fifty of the 62 B. cereus isolates were from imported seafood, and 19 (38%) of these samples were at levels > 100 CFU/g. Twelve of the 14 highest enterotoxin assay results were from isolates from imported food. Only one B. cereus isolate possessed the cereulide synthetase gene, ces; this isolate also possessed the genes for the three-component HBL and NHE complexes. A majority of enterotoxin-producing isolates were resistant to 2 of 10 antibiotics tested, ceftriaxone and clindamycin. Our results demonstrate the potential of seafood as a vehicle for foodborne illness caused by B. cereus, in particular the enterotoxin-producing genotype. PMID:18592743

Rahmati, T; Labbe, R

2008-06-01

132

Differential proteomic analysis of Clostridium perfringens ATCC13124; identification of dominant, surface and structure associated proteins  

PubMed Central

Background Clostridium perfringens is a medically important clostridial pathogen causing diseases in man and animals. To invade, multiply and colonize tissues of the host, a pathogen must be able to evade host immune system, and obtain nutrients essential for growth. The factors involved in these complex processes are largely unknown and of crucial importance to understanding microbial pathogenesis. Many of the virulence determinants and putative vaccine candidates for bacterial pathogens are known to be surface localized. Results Using 2-DE mass spectrometry strategy, we identified major surface (22) and cell envelope (10) proteins from Clostridium perfringens ATCC13124 and those differentially expressed (11) in cells grown on cooked meat medium (CMM) in comparison with cells grown in reference state (tryptose-yeast extract-glucose medium). Riboflavin biosynthesis protein, ornithine carbamoyltransferase, cystathionine beta-lyase, and threonine dehydratase were the predominant proteins that exhibited 2.19 to 8.5 fold increase in the expression level in cells growing on CMM. Conclusion Ornithine carbamoyltransferase and cystathionine beta-lyase were over-expressed in cells grown on cooked meat medium and also identified in the surface protein fraction and the former was immunogenic; making them potential vaccine candidates. Based upon bioinformatic analysis; choloylglycine hydrolase family protein, cell wall-associated serine proteinase, and rhomboid family protein were predicted as surface protein markers for specific detection of C. perfringens from the environment and food. Most of the proteins over-expressed in CMM were shown to have putative function in metabolism, of which seven were involved in amino acid transport and metabolism or lipid metabolism.

2009-01-01

133

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

PubMed

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 <1 log, regardless of the inoculum level. In addition, no growth was observed in any 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 <1-log growth of C. perfringens from spores was observed in the pH 5.63 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. PMID:23317858

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

2013-01-01

134

Association between avian necrotic enteritis and Clostridium perfringens strains expressing NetB toxin  

PubMed Central

A novel toxin, NetB, has recently been identified in virulent avian Clostridium perfringens isolates and shown to be an essential virulence factor in a clinical necrotic enteritis isolate. To assess whether NetB is more generally associated with avian necrotic enteritis isolates we have screened a range of C. perfringens strains from geographically diverse locations for both the presence and expression of the netB gene. Forty-four isolates were derived from necrotic enteritis disease cases from Australia, Belgium, Denmark and Canada and 55 isolates from healthy chickens from Australia and Belgium. The majority of strains isolated from necrotic enteritis-affected birds were netB positive (70%) and there was an absolute correlation between the presence of netB and in vitro expression of the NetB protein. Only two of the C. perfringens isolates from healthy chickens carried netB. Sequencing of the netB gene from 23 positive isolates showed that NetB is highly conserved, with only one predicted amino acid (A168T) difference, in six isolates, compared to the published sequence. This change did not alter the in vitro activity of the NetB toxin. The gene encoding the recently discovered TpeL toxin was also screened using PCR and only found in a small proportion of NetB-positive isolates from diseased birds. A selection of NetB-negative isolates, originating from diseased birds, was unable to cause disease in a necrotic enteritis induction model. This study provides further evidence that NetB is important in pathogenesis and advances our current understanding of C. perfringens virulence factors in avian necrotic enteritis.

Keyburn, Anthony L.; Yan, Xu-Xia; Bannam, Trudi L.; Van Immerseel, Filip; Rood, Julian I.; Moore, Robert J.

2009-01-01

135

Clostridium perfringens type A cytotoxic-enterotoxin(s) as triggers for death in the sudden infant death syndrome: Development of a toxico-infection hypothesis  

Microsoft Academic Search

In our studies with the pathogenic bacteriumClostridium perfringens type A and its cytotoxic-enterotoxins (CTEs), we have obtained results that imply an involvement of this organism in the sudden infant death syndrome (SIDS). In fecal samples obtained from SIDS infants (n=164) and non-SIDS infants (n=57),C. perfringens type A was present in high numbers in >80% of SIDS and C. perfringens type

James A. Lindsay; Annette S. Mach; Melissa A. Wilkinson; L. Michele Martin; F. Morgan Wallace; Andreas M. Keller; Lisa M. Wojciechowski

1993-01-01

136

Comparative Experiments To Examine the Effects of Heating on Vegetative Cells and Spores of Clostridium perfringens Isolates Carrying Plasmid Enterotoxin Genes versus Chromosomal Enterotoxin Genes  

Microsoft Academic Search

Clostridium perfringens enterotoxin (CPE) is an important virulence factor for both C. perfringens type A food poisoning and several non-food-borne human gastrointestinal diseases. Recent studies have indicated that C. perfringens isolates associated with food poisoning carry a chromosomal cpe gene, while non-food-borne human gastrointestinal disease isolates carry a plasmid cpe gene. However, no explanation has been provided for the strong

MAHFUZUR R. SARKER; ROBERT P. SHIVERS; SHAUNA G. SPARKS; VIJAY K. JUNEJA; B. A. McClane

2000-01-01

137

Production of a bacteriocin by a poultry derived Campylobacter jejuni isolate with antimicrobial activity against Clostridium perfringens and other Gram positive bacteria.  

Technology Transfer Automated Retrieval System (TEKTRAN)

We have purified a bacteriocin peptide (termed CUV-3), produced by a poultry cecal isolate of Campylobacter jejuni (strain CUV-3) with inhibitory activity against Gram positive bacteria including Clostridium perfringens (38 strains), Staphylococcus aureus, Staphylococcus epidermidis and Listeria mon...

138

Ultrastructural Studies on the Lesion Produced in Skeletal Muscle Fibers by Crude Type a Clostridium Perfringens Toxin and Its Purified alpha Fraction.  

National Technical Information Service (NTIS)

Myonecrosis produced by Clostridium perfringens alpha toxin (lecithinase C) has been studied extensively in the past without definite demonstration of an initial lesion in the skeletal muscle cell. The properties of the alpha toxin have been investigated ...

S. W. Strunk C. W. Smith J. M. Blumberg

1966-01-01

139

Identification of Clostridium Species and DNA Fingerprinting of Clostridium perfringens by Amplified Fragment Length Polymorphism Analysis  

Microsoft Academic Search

An amplified fragment length polymorphism (AFLP) method was applied to 129 strains representing 24 different Clostridium species, with special emphasis on pathogenic clostridia of medical or veterinary interest, to assess the potential of AFLP for identification of clostridia. In addition, the ability of the same AFLP protocol to type clostridia at the strain level was assessed by focusing on Clostridium

Riikka Keto-Timonen; Annamari Heikinheimo; Erkki Eerola; Hannu Korkeala

2006-01-01

140

Pediocin A improves growth performance of broilers challenged with Clostridium perfringens.  

PubMed

The aim of this study was to investigate the efficacy of the anticlostridial pediocin A from Pediococcus pentosaceus FBB61 to contain negative effects associated to Clostridium proliferation in broilers, through 2 subsequent investigations. In the first study, 36 Ross 508 broilers were divided into 3 groups and fed for 21 d as follows: the control diet (CTR), the control diet supplemented with supernatant filtrate of a culture of P. pentosaceus FBB61-2 (Bac-, isogenic mutant nonproducing pediocin A), and the control diet supplemented with supernatant filtrate of a culture of P. pentosaceus FBB61 (Bac+) containing pediocin A. Birds were challenged with 10(6) cells of Clostridium perfringens. In the second study, 216 Ross 508 broilers were allocated in 18 pens and divided into 3 groups fed the same diet for 42 d: a control group (CTR), a group challenged with 10(8) cells of C. perfringens (CP), and a group challenged with 10(8) cells of C. perfringens and receiving the control diet supplemented with P. pentosaceus FBB61 and pediocin A (PA). Broiler BW, ADG, ADFI, and feed conversion rate were measured throughout the studies. At the end of both experiments, an appropriate number of birds was killed and analyzed for necrotic enteritis lesions and microbiological examinations. In the first study, on d 9, ADG and BW were 20% higher for Bac+ compared with CTR and Bac-; on d 14, ADG was higher for Bac+ (+23%, P<0.05), whereas BW was higher for Bac+ and Bac- compared with CTR (+23 and +14%, respectively; P<0.05). In the second study, on d 14, ADG and BW were higher for PA compared with CTR and CP (+15% on average; P<0.05), whereas between 15 and 42 d, there was only a tendency toward a higher ADG for PA when compared with the CP group (+4%, P=0.08). Diet supplementation with pediocin A improved broiler growth performance during the challenge with C. perfringens and tended to restore the ADG depletion during the 42-d period. PMID:19762869

Grilli, E; Messina, M R; Catelli, E; Morlacchini, M; Piva, A

2009-10-01

141

The successful experimental induction of necrotic enteritis in chickens by Clostridium perfringens: a critical review  

PubMed Central

Necrotic enteritis (NE) is one of the most important enteric diseases in poultry and is a high cost to the industry worldwide. It is caused by avian-specific, Necrotic Enteritis Beta toxin (NetB)-producing, strains of Clostridium perfringens that also possess in common other virulence-associated genes. In Europe the disease incidence has increased since the ban on in-feed “growth promoting” antibiotics. Because of this, many recent studies of NE have focused on finding different ways to control the disease, and on understanding its pathogenesis. Frustratingly, reproduction of the disease has proven impossible for some researchers. This review describes and discusses factors known to be important in reproducing the disease experimentally, as well as other considerations in reproducing the disease. The critical bacterial factor is the use of virulent, netB-positive, strains; virulence can be enhanced by using tpeL- positive strains and by the use of young rather than old broth cultures to increase toxin expression. Intestinal damaging factors, notably the use of concurrent or preceding coccidial infection, or administration of coccidial vaccines, combined with netB-positive C. perfringens administration, can also be used to induce NE. Nutritional factors, particularly feeding high percentage of cereals containing non-starch polysaccharides (NSP) (wheat, rye, and barley) enhance disease by increasing digesta viscosity, mucus production and bacterial growth. Animal proteins, especially fish meal, enhance C. perfringens proliferation and toxin production. Other factors are discussed that may affect outcome but for which evidence of their importance is lacking. The review compares the different challenge approaches; depending on the aim of particular studies, the different critical factors can be adjusted to affect the severity of the lesions induced. A standardized scoring system is proposed for international adoption based on gross rather than histopathological lesions; if universally adopted this will allow better comparison between studies done by different researchers. Also a scoring system is provided to assist decisions on humane euthanasia of sick birds.

2012-01-01

142

Identification of novel pathogenicity loci in Clostridium perfringens strains that cause avian necrotic enteritis.  

PubMed

Type A Clostridium perfringens causes poultry necrotic enteritis (NE), an enteric disease of considerable economic importance, yet can also exist as a member of the normal intestinal microbiota. A recently discovered pore-forming toxin, NetB, is associated with pathogenesis in most, but not all, NE isolates. This finding suggested that NE-causing strains may possess other virulence gene(s) not present in commensal type A isolates. We used high-throughput sequencing (HTS) technologies to generate draft genome sequences of seven unrelated C. perfringens poultry NE isolates and one isolate from a healthy bird, and identified additional novel NE-associated genes by comparison with nine publicly available reference genomes. Thirty-one open reading frames (ORFs) were unique to all NE strains and formed the basis for three highly conserved NE-associated loci that we designated NELoc-1 (42 kb), NELoc-2 (11.2 kb) and NELoc-3 (5.6 kb). The largest locus, NELoc-1, consisted of netB and 36 additional genes, including those predicted to encode two leukocidins, an internalin-like protein and a ricin-domain protein. Pulsed-field gel electrophoresis (PFGE) and Southern blotting revealed that the NE strains each carried 2 to 5 large plasmids, and that NELoc-1 and -3 were localized on distinct plasmids of sizes approximately 85 and approximately 70 kb, respectively. Sequencing of the regions flanking these loci revealed similarity to previously characterized conjugative plasmids of C. perfringens. These results provide significant insight into the pathogenetic basis of poultry NE and are the first to demonstrate that netB resides in a large, plasmid-encoded locus. Our findings strongly suggest that poultry NE is caused by several novel virulence factors, whose genes are clustered on discrete pathogenicity loci, some of which are plasmid-borne. PMID:20532244

Lepp, Dion; Roxas, Bryan; Parreira, Valeria R; Marri, Pradeep R; Rosey, Everett L; Gong, Joshua; Songer, J Glenn; Vedantam, Gayatri; Prescott, John F

2010-05-24

143

Genome Sequencing and Analysis of a Type A Clostridium perfringens Isolate from a Case of Bovine Clostridial Abomasitis  

PubMed Central

Clostridium perfringens is a common inhabitant of the avian and mammalian gastrointestinal tracts and can behave commensally or pathogenically. Some enteric diseases caused by type A C. perfringens, including bovine clostridial abomasitis, remain poorly understood. To investigate the potential basis of virulence in strains causing this disease, we sequenced the genome of a type A C. perfringens isolate (strain F262) from a case of bovine clostridial abomasitis. The ?3.34 Mbp chromosome of C. perfringens F262 is predicted to contain 3163 protein-coding genes, 76 tRNA genes, and an integrated plasmid sequence, Cfrag (?18 kb). In addition, sequences of two complete circular plasmids, pF262C (4.8 kb) and pF262D (9.1 kb), and two incomplete plasmid fragments, pF262A (48.5 kb) and pF262B (50.0 kb), were identified. Comparison of the chromosome sequence of C. perfringens F262 to complete C. perfringens chromosomes, plasmids and phages revealed 261 unique genes. No novel toxin genes related to previously described clostridial toxins were identified: 60% of the 261 unique genes were hypothetical proteins. There was a two base pair deletion in virS, a gene reported to encode the main sensor kinase involved in virulence gene activation. Despite this frameshift mutation, C. perfringens F262 expressed perfringolysin O, alpha-toxin and the beta2-toxin, suggesting that another regulation system might contribute to the pathogenicity of this strain. Two complete plasmids, pF262C (4.8 kb) and pF262D (9.1 kb), unique to this strain of C. perfringens were identified.

Nowell, Victoria J.; Kropinski, Andrew M.; Songer, J. Glenn; MacInnes, Janet I.; Parreira, Valeria R.; Prescott, John F.

2012-01-01

144

Endogenous radiolabeling of enterotoxin from Clostridium perfringens type A on a defined medium.  

PubMed Central

Four enterotoxin-positive strains of Clostridium perfringens were tested for sporulation and enterotoxin production on defined media. The medium described by Sacks and Thompson (Appl. Environ. Microbiol. 35:405-409, 1978) gave the highest enterotoxin production and was selected for the production of endogenously labeled enterotoxin. The specific radioactivity of the enterotoxin was 16,000 dpm/microgram when the tritiated amino acids were added to the growth medium just before the inoculum. Addition of the radioactive amino acids during the growth period gave consistently lower specific radioactivity. When the enterotoxin was produced on the medium described by Duncan and Strong (Appl. Microbiol. 16:82-89, 1968), the highest specific radioactivity of the enterotoxin was found when the radioactive amino acids were added to the growth medium 4 h after inoculation. In this case, the specific activity of the enterotoxin was 10,000 dpm/microgram.

Granum, P E; Skjelkvale, R

1981-01-01

145

Specificity of Interaction between Clostridium perfringens Enterotoxin and Claudin-Family Tight Junction Proteins  

PubMed Central

Clostridium perfringens enterotoxin (CPE), a major cause of food poisoning, forms physical pores in the plasma membrane of intestinal epithelial cells. The ability of CPE to recognize the epithelium is due to the C-terminal binding domain, which binds to a specific motif on the second extracellular loop of tight junction proteins known as claudins. The interaction between claudins and CPE plays a key role in mediating CPE toxicity by facilitating pore formation and by promoting tight junction disassembly. Recently, the ability of CPE to distinguish between specific claudins has been used to develop tools for studying roles for claudins in epithelial barrier function. Moreover, the high affinity of CPE to selected claudins makes CPE a useful platform for targeted drug delivery to tumors expressing these claudins.

Mitchell, Leslie A.; Koval, Michael

2010-01-01

146

Characterization of the enzymatic activity of Clostridium perfringens TpeL.  

PubMed

TpeL is a toxin produced by Clostridium perfringens which belongs to the large clostridial glucosylating toxin family. It was shown that TpeL modifies Ras using UDP-glucose or UDP-N-acetylglucosamine as cosubstrates (Guttenberg et al., 2012; Nagahama et al., 2011). We confirmed that TpeL preferentially glucosaminates the three isoforms of Ras (cH-Ras, N-Ras, and K-Ras) from UDP-N-acetylglucosamine and to a lower extent Rap1a and R-Ras3, and very weakly Rac1. In contrast to previous report, we observed that Ral was not a substrate of TpeL. In addition, we confirmed by in vitro glucosylation and mass spectrometry that TpeL modifies cH-Ras at Thr35. PMID:23851225

Pauillac, Serge; D'allayer, Jacques; Lenormand, Pascal; Rousselle, Jean Claude; Bouvet, Philippe; Popoff, Michel R

2013-07-12

147

[New insight from basic research of Clostridium perfringens alpha-toxin].  

PubMed

Clostridium perfringens causes gas gangrene with inflammatory myopathies and infrequently septicemia associated with massive intravascular hemolysis. The microorganism is known to produce a variety of toxins and enzymes that are responsible for severe myonecrotic lesions. Notably, alpha-toxin, which possesses hemolytic, necrotic and lethal activities, and phospholipase C and sphingomyelinase activities, is an important agent for the diseases. The cytokine storm induced by alpha-toxin, mainly the release of TNF-alpha, plays an important role in the death and massive hemolysis. The toxin-induced release of TNF-alpha from neutrophils and macrophages is dependent on the activation of ERK1/2 signal transduction via TrkA receptor. In addition, 14- and 15-membered macrolides specifically block the toxin-induced events through the activation of neutrophils and macrophages. PMID:22894064

Oda, Masataka

2012-08-01

148

Purification and characterization of an extracellular alpha-amylase from Clostridium perfringens type A.  

PubMed Central

An alpha-amylase (EC 3.2.1.1) secreted by Clostridium perfringens NCTC 8679 type A was purified to homogeneity and characterized. It was isolated from concentrated cell-free culture medium by ion-exchange and gel permeation chromatography. The enzyme exhibited maximal activity at pH 6.5 and 30 degrees C without the presence of calcium. The pI of the enzyme was 4.75. The estimated molecular weight of the purified enzyme was 76 kDa. The purified enzyme was inactivated between 35 and 40 degrees C, which increased to between 45 and 50 degrees C in the presence of calcium (5 mM). The purified enzyme produced a mixture of oligosaccharides as major end products of starch hydrolysis, indicating alpha-amylase activity.

Shih, N J; Labbe, R G

1995-01-01

149

Biochemistry and Physiology of the ? Class Carbonic Anhydrase (Cpb) from Clostridium perfringens Strain 13  

PubMed Central

The carbonic anhydrase (Cpb) from Clostridium perfringens strain 13, the only carbonic anhydrase encoded in the genome, was characterized both biochemically and physiologically. Heterologously produced and purified Cpb was shown to belong to the type I subclass of the ? class, the first ? class enzyme investigated from a strictly anaerobic species of the domain Bacteria. Kinetic analyses revealed a two-step, ping-pong, zinc-hydroxide mechanism of catalysis with Km and kcat/Km values of 3.1 mM CO2 and 4.8 × 106 s?1 M?1, respectively. Analyses of a cpb deletion mutant of C. perfringens strain HN13 showed that Cpb is strictly required for growth when cultured in semidefined medium and an atmosphere without CO2. The growth of the mutant was the same as that of the parent wild-type strain when cultured in nutrient-rich media with or without CO2 in the atmosphere, although elimination of glucose resulted in decreased production of acetate, propionate, and butyrate. The results suggest a role for Cpb in anaplerotic CO2 fixation reactions by supplying bicarbonate to carboxylases. Potential roles in competitive fitness are discussed.

Kumar, R. Siva Sai; Hendrick, William; Correll, Jared B.; Patterson, Andrew D.; Melville, Stephen B.

2013-01-01

150

Origin of Clostridium perfringens isolates determines the ability to induce necrotic enteritis in broilers.  

PubMed

Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions. PMID:18783830

Timbermont, Leen; Lanckriet, Anouk; Gholamiandehkordi, Ahmad R; Pasmans, Frank; Martel, An; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

2008-09-09

151

A Paracrystalline Inclusion Formed During Sporulation of Enterotoxin-Producing Strains of Clostridium perfringens Type A  

PubMed Central

A large paracrystalline inclusion is formed by certain strains of Clostridium perfringens type A during spore morphogenesis. In most cell thin sections, the inclusion appeared rod-shaped when sectioned at an angle perpendicular to its longer axis, and circular or oval-shaped when sectioned at an angle parallel to its longer axis. Measurements performed on electron micrographs of inclusions sectioned to reveal the rod shape indicated a fairly consistent thickness (width) of 192 ± 23 nm. The length of the inclusions varied considerably with a maximum of approximately 2,120 nm being observed. Ultrastructurally, the inclusion was composed of closely packed, periodically spaced, parallel layers. Usually a single inclusion was randomly located in the cytoplasm of the cell. Two inclusions per cell were rarely observed. The inclusion was formed only by ent+ strains of C. perfringens. Mutants of the ent+ strain NCTC 8798 that were altered in their sporulating and enterotoxin-producing capacities and revertants of these mutants were tested for inclusion formation. The results indicate that, as with the ent+ trait, a direct relationship exists between inclusion formation and spore formation. The synthesis of enterotoxin, formation of a morphologically distinct inclusion, and the initial deposition of discontinuous coat fragments around the forespore appear to be events closely related in time during spore morphogenesis. Images

Duncan, Charles L.; King, Gretchen J.; Frieben, William R.

1973-01-01

152

Influence of peptone source on sporulation of Clostridium perfringens type A.  

PubMed

Clostridium perfringens is a foodborne disease agent that produces a sporulation-specific enterotoxin. To produce enterotoxin for experimental purposes or spores for challenge or physiological studies, the use of a convenient sporulation medium is required. The most commonly used is Duncan-Strong medium. Few isolates sporulate at high levels in this medium. We investigated the effectiveness of peptones from a variety of sources on the sporulation of this organism compared with the peptone in the original formulation, proteose peptone (control). Seven strains were used to screen 32 peptones, with starch or raffinose as the carbohydrate source. In most cases, raffinose was more effective than starch in stimulating sporulation, confirming our previous study. Two promising peptones, potato peptone, and Proteose Peptone no. 3, were selected and tested against 49 additional enterotoxin-positive and -negative strains, with raffinose as the carbohydrate. For 49 strains, 5 sporulated best (>10%) in the control peptone, 6 sporulated best in Peptone no. 3, and 23 sporulated best in the potato peptone. Of the 23 strains, 16 sporulated at levels 25% more than the control peptone. The increase in sporulation rates was reflected in the enterotoxin and heat-resistant spore levels. The methylxanthines caffeine and theobromine were effective in increasing the sporulation of less than half of 19 enterotoxin-positive strains. Our results suggest that the replacement of proteose peptone with potato peptone be considered if difficulty in obtaining spores of specific strains of C. perfringens is encountered. PMID:17685351

Hsieh, P Y; Labbe, R

2007-07-01

153

Development of a minimal medium for Clostridium perfringens by using an anaerobic chemostat.  

PubMed Central

A minimal medium was developed for the cultivation of Clostridium perfringens in an anaerobic chemostat. Cultures of C. perfringens ATCC 3624 and NCTC 10240 were grown at 46 and 43 degrees C, respectively, in a glucose-limited, chemically defined medium at pH 7.2. The concentrations of amino acids, minerals, nucleotides, and vitamins, initially present in excess, were varied independently. The minimum concentration of each nutrient which would support 3 X 10(8) CFU/ml with a generation time of less than 40 min was determined and used to develop a reformulated defined medium. Atomic absorption spectroscopy and amino acid analyses of the reformulated medium indicated additional adjustments in nutrient content which led to the development of a minimal medium for each strain. The nutritional profile for each strain was similar. A decrease in the concentration of arginine, histidine, and tyrosine for strain 3624 and of arginine, histidine, and isoleucine for strain 10240 resulted in an increase in the optical density of each culture.

Goldner, S B; Solberg, M; Post, L S

1985-01-01

154

Alpha toxin from Clostridium perfringens induces proinflammatory changes in endothelial cells.  

PubMed Central

Alpha toxin from Clostridium perfringens type A, a phospholipase C, has been implicated in many of the localized and systemic features of gas gangrene. We demonstrated that human endothelial cells synthesize two vasoactive lipids, platelet-activating factor (PAF) and prostacyclin, in response to alpha toxin treatment. The stimulated synthesis of PAF required the enzymatic activity of the toxin and subsequent protein kinase C activation. Alpha toxin-treated endothelial cells accumulated the products of the phospholipase C reaction, diacylglycerol and ceramide, and exhibited a decrease in the enzymatic precursors phosphatidylcholine and sphingomyelin. Furthermore, the temporal accumulation of PAF depended on the concentration of the toxin in the overlying medium and was blocked in the presence of a neutralizing antibody. The cultured endothelial cells also exhibited enhanced neutrophil adhesion in response to alpha toxin which was mediated through the PAF receptor and P-selectin. P-selectin expression by endothelial cells and extravascular neutrophil accumulation were also observed in tissue sections from alpha toxin-injected Sprague-Dawley rats. These endothelial cell-mediated processes are important in maintaining vascular homeostasis and, when activated in a dysregulated manner by C. perfringens alpha toxin, may contribute to localized and systemic manifestations of gas gangrene including enhanced vascular permeability, localized neutrophil accumulation, and myocardial dysfunction.

Bunting, M; Lorant, D E; Bryant, A E; Zimmerman, G A; McIntyre, T M; Stevens, D L; Prescott, S M

1997-01-01

155

In vivo studies of Clostridium perfringens in mouse gas gangrene model.  

PubMed

Understanding the pathogenesis of infectious diseases requires comprehensive knowledge of the proteins expressed by the pathogen during in vivo growth in the host. Proteomics provides the tools for such analyses but the protocols required to purify sufficient quantities of the pathogen from the host organism are currently lacking. In this study, we have separated Clostridium perfringens, a highly virulent bacterium and potential BTW agent, from the peritoneal fluid of infected mice using Percoll density gradient centrifugation. The bacterium could be isolated in quantities sufficient to carry out meaningful proteomic comparisons with in vitro grown bacteria. Furthermore, the isolates were found to be virtually free from contaminating host proteins. Microscopy revealed major morphological changes under host conditions at different stages of infection. Profile of immunogenic proteins from in vivo- and TPYG-grown whole cell lysate using mouse anti-gangrene serum indicated over-expression of several proteins especially in the low molecular weight region. Expression of two virulence determinants, ornithine carbamoyl transferase (cOTC), and cystathionine beta-lyase (CBL), under in vivo conditions has also been studied. Two-dimensional gel analysis revealed a host induced proteome which was apparently different in comparison to in vitro grown cells. Detailed proteomic elucidation of differentially expressed proteins shown here is likely to provide valuable insight towards understanding the complexity of the adaptive response of C. perfringens to the host environment. PMID:21086128

Sengupta, Nabonita; Alam, Syed Imteyaz

2010-11-19

156

Construction of an Alpha Toxin Gene Knockout Mutant of Clostridium perfringens Type A by Use of a Mobile Group II Intron  

PubMed Central

In developing Clostridium perfringens as a safe vaccine vector, the alpha toxin gene (plc) in the bacterial chromosome must be permanently inactivated. Disrupting genes in C. perfringens by traditional mutagenesis methods is very difficult. Therefore, we developed a new strategy using group II intron-based Target-Tron technology to inactivate the plc gene in C. perfringens ATCC 3624. Western blot analysis showed no production of alpha toxin protein in the culture supernatant of the plc mutant. Advantages of this technology, such as site specificity, relatively high frequency of insertion, and introduction of no antibiotic resistance genes into the chromosome, could facilitate construction of other C. perfringens mutants.

Chen, Yue; McClane, Bruce A.; Fisher, Derek J.; Rood, Julian I.; Gupta, Phalguni

2005-01-01

157

Co-infection with Toxoplasma gondii and Clostridium perfringens in a postpartum woman with uterine gas gangrene: a case report.  

PubMed

Toxoplasmosis is a protozoan infection caused by Toxoplasma gondii. We report a case of Toxoplasma gondii and Clostridium perfringens co-infection complicating uterine gas gangrene following a term pregnancy. The histological examination of the necrotic uterine tissues and uterine swab cultures obtained at laparotomy revealed T. gondii and C. perfringens, respectively. Treatment was administered with bactericidal activity against both pathogens and the patient had an uneventful post-operative recovery. Although there have been some cases that have documented an association between toxoplasmosis and non-uterine C. perfringens infection, such a relationship has not been established. It is of interest to determine if the presence of both organisms can explain the severe myonecrosis that occurs in some cases of uterine gas gangrene. PMID:22487420

Alsammani, Mohamed Alkhatim; Ahmed, Salah Roshdy; Alsheeha, Muneera A; Saadia, Zaheera; Khairi, Somia A

2012-04-09

158

Structural and functional analysis of the pore-forming toxin NetB from Clostridium perfringens.  

PubMed

Clostridium perfringens is an anaerobic bacterium that causes numerous important human and animal diseases, primarily as a result of its ability to produce many different protein toxins. In chickens, C. perfringens causes necrotic enteritis, a disease of economic importance to the worldwide poultry industry. The secreted pore-forming toxin NetB is a key virulence factor in the pathogenesis of avian necrotic enteritis and is similar to alpha-hemolysin, a ?-barrel pore-forming toxin from Staphylococcus aureus. To address the molecular mechanisms underlying NetB-mediated tissue damage, we determined the crystal structure of the monomeric form of NetB to 1.8 Å. Structural comparisons with other members of the alpha-hemolysin family revealed significant differences in the conformation of the membrane binding domain. These data suggested that NetB may recognize different membrane receptors or use a different mechanism for membrane-protein interactions. Consistent with this idea, electrophysiological experiments with planar lipid bilayers revealed that NetB formed pores with much larger single-channel conductance than alpha-hemolysin. Channel conductance varied with phospholipid net charge. Furthermore, NetB differed in its ion selectivity, preferring cations over anions. Using hemolysis as a screen, we carried out a random-mutagenesis study that identified several residues that are critical for NetB-induced cell lysis. Mapping of these residues onto the crystal structure revealed that they were clustered in regions predicted to be required for oligomerization or membrane binding. Together these data provide an insight into the mechanism of NetB-mediated pore formation and will contribute to our understanding of the mode of action of this important toxin. IMPORTANCE Necrotic enteritis is an economically important disease of the worldwide poultry industry and is mediated by Clostridium perfringens strains that produce NetB, a ?-pore-forming toxin. We carried out structural and functional studies of NetB to provide a mechanistic insight into its mode of action and to assist in the development of a necrotic enteritis vaccine. We determined the structure of the monomeric form of NetB to 1.8 Å, used both site-directed and random mutagenesis to identify key residues that are required for its biological activity, and analyzed pore formation by NetB and its substitution-containing derivatives in planar lipid bilayers. PMID:23386432

Yan, Xu-Xia; Porter, Corrine J; Hardy, Simon P; Steer, David; Smith, A Ian; Quinsey, Noelene S; Hughes, Victoria; Cheung, Jackie K; Keyburn, Anthony L; Kaldhusdal, Magne; Moore, Robert J; Bannam, Trudi L; Whisstock, James C; Rood, Julian I

2013-02-05

159

Global regulation of gene expression in response to cysteine availability in Clostridium perfringens  

PubMed Central

Background Cysteine has a crucial role in cellular physiology and its synthesis is tightly controlled due to its reactivity. However, little is known about the sulfur metabolism and its regulation in clostridia compared with other firmicutes. In Clostridium perfringens, the two-component system, VirR/VirS, controls the expression of the ubiG operon involved in methionine to cysteine conversion in addition to the expression of several toxin genes. The existence of links between the C. perfringens virulence regulon and sulfur metabolism prompted us to analyze this metabolism in more detail. Results We first performed a tentative reconstruction of sulfur metabolism in C. perfringens and correlated these data with the growth of strain 13 in the presence of various sulfur sources. Surprisingly, C. perfringens can convert cysteine to methionine by an atypical still uncharacterized pathway. We further compared the expression profiles of strain 13 after growth in the presence of cystine or homocysteine that corresponds to conditions of cysteine depletion. Among the 177 genes differentially expressed, we found genes involved in sulfur metabolism and controlled by premature termination of transcription via a cysteine specific T-box system (cysK-cysE, cysP1 and cysP2) or an S-box riboswitch (metK and metT). We also showed that the ubiG operon was submitted to a triple regulation by cysteine availability via a T-box system, by the VirR/VirS system via the VR-RNA and by the VirX regulatory RNA. In addition, we found that expression of pfoA (theta-toxin), nagL (one of the five genes encoding hyaluronidases) and genes involved in the maintenance of cell redox status was differentially expressed in response to cysteine availability. Finally, we showed that the expression of genes involved in [Fe-S] clusters biogenesis and of the ldh gene encoding the lactate dehydrogenase was induced during cysteine limitation. Conclusion Several key functions for the cellular physiology of this anaerobic bacterium were controlled in response to cysteine availability. While most of the genes involved in sulfur metabolism are regulated by premature termination of transcription, other still uncharacterized mechanisms of regulation participated in the induction of gene expression during cysteine starvation.

2010-01-01

160

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

PubMed

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. PMID:11153223

Aschfalk, A; Müller, W; Drochner, W

161

Detergent-Resistant Membrane Microdomains Facilitate Ib Oligomer Formation and Biological Activity of Clostridium perfringens Iota-Toxin  

Microsoft Academic Search

Clostridium perfringens iota-toxin consists of two separate proteins identified as a cell binding protein, iota b (Ib), which forms high-molecular-weight complexes on cells generating Na\\/K-permeable pores through which iota a (Ia), an ADP-ribosyltransferase, presumably enters the cytosol. Identity of the cell receptor and membrane domains involved in Ib binding, oligomer formation, and internalization is currently unknown. In this study, Vero

Martha L. Hale; Jean-Christophe Marvaud; Michel R. Popoff; Bradley G. Stiles

2004-01-01

162

Comparison of Different Methods of Cell Lysis and Protein Measurements in Clostridium perfringens: Application to the Cell Volume Determination  

Microsoft Academic Search

.   Four cell lysis methods (NaOH-SDS solubilization, French press treatment, sonication, mutanolysin treatment) and three methods\\u000a of protein assays (Lowry, Bradford, Pierce) were studied for their applicability to determination of cell volume in Clostridium perfringens NCTC 8798 cell suspensions. Protein contents were higher after a mechanical disruption of the cells than with the other techniques\\u000a of lysis. The lowest concentrations

Patrick Guerlava; Véronique Izac; Jean-Luc Tholozan

1998-01-01

163

Clostridium perfringens bacteriophages ?CP39O and ?CP26F: genomic organization and proteomic analysis of the virions  

Microsoft Academic Search

Poultry intestinal material, sewage and poultry processing drainage water were screened for virulent Clostridium perfringens bacteriophages. Viruses isolated from broiler chicken offal washes (O) and poultry feces (F), designated ?CP39O and ?CP26F,\\u000a respectively, produced clear plaques on host strains. Both bacteriophages had isometric heads of 57 nm in diameter with 100-nm\\u000a non-contractile tails characteristic of members of the family Siphoviridae in

Bruce S. Seal; Derrick E. Fouts; Mustafa Simmons; Johnna K. Garrish; Robin L. Kuntz; Rebekah Woolsey; Kathleen M. Schegg; Andrew M. Kropinski; Hans-W. Ackermann; Gregory R. Siragusa

2011-01-01

164

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

PubMed Central

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.

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

1996-01-01

165

A medium for the isolation, enumeration and rapid presumptive identification of injured Clostridium perfringens and Bacillus cereus.  

PubMed

A blood-free egg yolk medium (BCP) containing pyruvate, inositol, mannitol and a bromocresol purple indicator in a nutrient agar base has been developed to initiate the growth of Clostridium perfringens. It is comparable to blood agar for the growth of normal, chilled stored vegetative cells and heat-injured spores of Cl. perfringens and Bacillus cereus. It has the advantage over blood agar in exhibiting presumptive evidence of Cl. perfringens (production of lecithinase and inositol fermentation) after an overnight incubation at 43 degrees - 45 degrees C. Pyruvate, catalase and other hydrogen peroxide degraders were found to remove toxins rapidly formed in media exposed to air and light. Free radical scavengers of superoxide, hydroxyl ions and singlet oxygen were ineffective. Without scavengers the formation of 10-20 micrograms/ml hydrogen peroxide in the exposed medium was indicated and found lethal to injured Cl. perfringens. The BCP medium has been used successfully for the rapid identification and enumeration of Cl. perfringens in foods and faeces from food poisoning outbreaks and cases of suspected infectious diarrhoea. Greater recovery of severely injured vegetative Cl. perfrigens could be obtained by pre-incubation at 37 degrees C of inoculated media for 2-4 h followed by overnight incubation at 43 degrees - 45 degrees C. Tryptose-sulphite-cycloserine and Shahidi-Ferguson-perfringens agar base were found to inhibit the growth of several strains of injured vegetative Cl. perfringens. This was not completely overcome by the addition of pyruvate. The inclusion of mannitol also allows the medium to be used for the presumptive identification of B. cereus. Growth and lecithinase activity are profuse on BCP. Heat-injured spores are recovered equally well on BCP and blood agar. A scheme for the identification of some other clostridia on BCP is presented. PMID:2123173

Hood, A M; Tuck, A; Dane, C R

1990-09-01

166

Type IV pili-dependent gliding motility in the Gram-positive pathogen Clostridium perfringens and other Clostridia.  

PubMed

Bacteria can swim in liquid media by flagellar rotation and can move on surfaces via gliding or twitching motility. One type of gliding motility involves the extension, attachment and retraction of type IV pili (TFP), which pull the bacterium towards the site of attachment. TFP-dependent gliding motility has been seen in many Gram-negative bacteria but not in Gram-positive bacteria. Recently, the genome sequences of three strains of Clostridium perfringens have been completed and we identified gene products involved in producing TFP in each strain. Here we show that C. perfringens produces TFP and moves with an unusual form of gliding motility involving groups of densely packed cells moving away from the edge of a colony in curvilinear flares. Mutations introduced into the pilT and pilC genes of C. perfringens abolished motility and surface localization of TFP. Genes encoding TFP are also found in the genomes of all nine Clostridium species sequenced thus far and we demonstrated that Clostridium beijerinckii can move via gliding motility. It has recently been proposed that the Clostridia are the oldest Eubacterial class and the ubiquity of TFP in this class suggests that a Clostridia-like ancestor possessed TFP, which evolved into the forms seen in many Gram-negative species. PMID:16999833

Varga, John J; Nguyen, Van; O'Brien, David K; Rodgers, Katherine; Walker, Richard A; Melville, Stephen B

2006-09-25

167

Rapid, Simultaneous Detection of Clostridium sordellii and Clostridium perfringens in Archived Tissues by a Novel PCR-Based Microsphere Assay: Diagnostic Implications for Pregnancy-Associated Toxic Shock Syndrome Cases  

PubMed Central

Clostridium sordellii and Clostridium perfringens are infrequent human pathogens; however, the case-fatality rates for the infections are very high, particularly in obstetric C. sordellii infections (>90%). Deaths from Clostridium sordellii and Clostridium perfringens toxic shock (CTS) are sudden, and diagnosis is often challenging. Formalin-fixed, paraffin-embedded (FFPE) tissues usually are the only specimens available for sudden fatal cases, and immunohistochemistry (IHC) for Clostridia is generally performed but it cannot identify species. A clear need exists for a rapid, species-specific diagnostic assay for FFPE tissues. We developed a duplex PCR-based microsphere assay for simultaneous detection of C. sordellii and C. perfringens and evaluated DNA extracted from 42 Clostridium isolates and FFPE tissues of 28 patients with toxic shock/endometritis (20?CTS, 8?non-CTS, as confirmed by PCR and sequencing). The microsphere assay correctly identified C. sordellii and C. perfringens in all known isolates and in all CTS patients (10 C. sordellii, 8 C. perfringens, 2 both) and showed 100% concordance with PCR and sequencing results. The microsphere assay is a rapid, specific, and cost-effective method for the diagnosis of CTS and offers the advantage of simultaneous testing for C. sordellii and C. perfringens in FFPE tissues using a limited amount of DNA.

Bhatnagar, Julu; DeLeon-Carnes, Marlene; Kellar, Kathryn L.; Bandyopadhyay, Kakali; Antoniadou, Zoi-Anna; Shieh, Wun-Ju; Paddock, Christopher D.; Zaki, Sherif R.

2012-01-01

168

Effects of Clostridium perfringens beta-toxin on the rabbit small intestine and colon.  

PubMed

Clostridium perfringens type B and type C isolates, which produce beta-toxin (CPB), cause fatal diseases originating in the intestines of humans or livestock. Our previous studies demonstrated that CPB is necessary for type C isolate CN3685 to cause bloody necrotic enteritis in a rabbit ileal loop model and also showed that purified CPB, in the presence of trypsin inhibitor (TI), can reproduce type C pathology in rabbit ileal loops. We report here a more complete characterization of the effects of purified CPB in the rabbit small and large intestines. One microgram of purified CPB, in the presence of TI, was found to be sufficient to cause significant accumulation of hemorrhagic luminal fluid in duodenal, jejunal, or ileal loops treated for 6 h with purified CPB, while no damage was observed in corresponding loops receiving CPB (no TI) or TI alone. In contrast to the CPB sensitivity of the small intestine, the colon was not affected by 6 h of treatment with even 90 mug of purified CPB whether or not TI was present. Time course studies showed that purified CPB begins to induce small intestinal damage within 1 h, at which time the duodenum is less damaged than the jejunum or ileum. These observations help to explain why type B and C infections primarily involve the small intestine, establish CPB as a very potent and fast-acting toxin in the small intestines, and confirm a key role for intestinal trypsin as an innate intestinal defense mechanism against CPB-producing C. perfringens isolates. PMID:18625730

Vidal, Jorge E; McClane, Bruce A; Saputo, Juliann; Parker, Jaquelyn; Uzal, Francisco A

2008-07-14

169

Virulence of Clostridium perfringens in an experimental model of poultry necrotic enteritis.  

PubMed

Poultry necrotic enteritis (NE) has, over recent decades, been prevented and treated by addition of antimicrobials to poultry feed. Recent bans of antimicrobial growth promoters in feed, as well as other factors, have led to a slow, worldwide re-emergence of NE. Understanding of pathogenesis of NE has been hampered by lack of a consistent and effective experimental model in which virulence of strains can be reliably evaluated, with an endpoint yielding lesions comparable to those seen in acute NE in the field. The overall objective of this work was to develop an experimental approach that would allow consistent production of a full range of clinical signs and lesions of the disease, and to do so without use of coccidia as inciting agents. In addition, we assessed the virulence of strains of Clostridium perfringens from field cases of NE. Broiler chicks fed a commercial chick starter for 7 days post-hatch were switched to a high protein feed mixed 50:50 with fishmeal for an additional 7 days. On day 14, feed was withheld for 20 h, and birds were then offered feed mixed with C. perfringens (3 parts culture to 4 parts feed) twice daily on 4 consecutive days. On average, >75% of challenged birds developed typical gross lesions when inoculated with type A strains from field cases of NE. In addition, in vivo passage apparently increases strain virulence. Virulence varies from strain-to-strain; NetB-producing strains were virulent, as were some NetB non-producing strains. PMID:19931323

Cooper, Kerry K; Songer, J Glenn

2009-10-20

170

Comparative transcription analysis and toxin production of two fluoroquinolone-resistant mutants of Clostridium perfringens  

PubMed Central

Background Fluoroquinolone use has been listed as a risk factor for the emergence of virulent clinical strains of some bacteria. The aim of our study was to evaluate the effect of fluoroquinolone (gatifloxacin) resistance selection on differential gene expression, including the toxin genes involved in virulence, in two fluoroquinolone-resistant strains of Clostridium perfringens by comparison with their wild-type isogenic strains. Results DNA microarray analyses were used to compare the gene transcription of two wild types, NCTR and ATCC 13124, with their gatifloxacin-resistant mutants, NCTRR and 13124R. Transcription of a variety of genes involved in bacterial metabolism was either higher or lower in the mutants than in the wild types. Some genes, including genes for toxins and regulatory genes, were upregulated in NCTRR and downregulated in 13124R. Transcription analysis by quantitative real-time PCR (qRT-PCR) confirmed the altered expression of many of the genes that were affected differently in the fluoroquinolone-resistant mutants and wild types. The levels of gene expression and enzyme production for the toxins phospholipase C, perfringolysin O, collagenase and clostripain had decreased in 13124R and increased in NCTRR in comparison with the wild types. After centrifugation, the cytotoxicity of the supernatants of NCTRR and 13224R cultures for mouse peritoneal macrophages confirmed the increased cytotoxicity of NCTRR and the decreased cytotoxicity of 13124R in comparison with the respective wild types. Fluoroquinolone resistance selection also affected cell shape and colony morphology in both strains. Conclusion Our results indicate that gatifloxacin resistance selection was associated with altered gene expression in two C. perfringens strains and that the effect was strain-specific. This study clearly demonstrates that bacterial exposure to fluoroquinolones may affect virulence (toxin production) in addition to drug resistance.

2013-01-01

171

Regulation of virulence by the RevR response regulator in Clostridium perfringens.  

PubMed

Clostridium perfringens causes clostridial myonecrosis or gas gangrene and produces several extracellular hydrolytic enzymes and toxins, many of which are regulated by the VirSR signal transduction system. The revR gene encodes a putative orphan response regulator that has similarity to the YycF (WalR), VicR, PhoB, and PhoP proteins from other Gram-positive bacteria. RevR appears to be a classical response regulator, with an N-terminal receiver domain and a C-terminal domain with a putative winged helix-turn-helix DNA binding region. To determine its functional role, a revR mutant was constructed by allelic exchange and compared to the wild type by microarray analysis. The results showed that more than 100 genes were differentially expressed in the mutant, including several genes involved in cell wall metabolism. The revR mutant had an altered cellular morphology; unlike the short rods observed with the wild type, the mutant cells formed long filaments. These changes were reversed upon complementation with a plasmid that carried the wild-type revR gene. Several genes encoding extracellular hydrolytic enzymes (sialidase, hyaluronidase, and ?-clostripain) were differentially expressed in the revR mutant. Quantitative enzyme assays confirmed that these changes led to altered enzyme activity and that complementation restored the wild-type phenotype. Most importantly, the revR mutant was attenuated for virulence in the mouse myonecrosis model compared to the wild type and the complemented strains. These results provide evidence that RevR regulates virulence in C. perfringens; it is the first response regulator other than VirR to be shown to regulate virulence in this important pathogen. PMID:21402758

Hiscox, Thomas J; Chakravorty, Anjana; Choo, Jocelyn M; Ohtani, Kaori; Shimizu, Tohru; Cheung, Jackie K; Rood, Julian I

2011-03-14

172

The effect of Clostridium perfringens type C strain CN3685 and its isogenic beta toxin null mutant in goats.  

PubMed

Clostridium perfringens type C is an important cause of enteritis and/or enterocolitis in several animal species, including pigs, sheep, goats, horses and humans. The disease is a classic enterotoxemia and the enteric lesions and associated systemic effects are thought to be caused primarily by beta toxin (CPB), one of two typing toxins produced by C. perfringens type C. This has been demonstrated recently by fulfilling molecular Koch's postulates in rabbits and mice. We present here an experimental study to fulfill these postulates in goats, a natural host of C. perfringens type C disease. Nine healthy male or female Anglo Nubian goat kids were inoculated with the virulent C. perfringens type C wild-type strain CN3685, an isogenic CPB null mutant or a strain where the cpb null mutation had been reversed. Three goats inoculated with the wild-type strain presented abdominal pain, hemorrhagic diarrhea, necrotizing enterocolitis, pulmonary edema, hydropericardium and death within 24h of inoculation. Two goats inoculated with the CPB null mutant and two goats inoculated with sterile culture media (negative controls) remained clinically healthy during 24h after inoculation and no gross or histological abnormalities were observed in the tissues of any of them. Reversal of the null mutation to partially restore CPB production also increased virulence; 2 goats inoculated with this reversed mutant presented clinical and pathological changes similar to those observed in goats inoculated with the wild-type strain, except that spontaneous death was not observed. These results indicate that CPB is required for C. perfringens type C to induce disease in goats, supporting a key role for this toxin in natural C. perfringens type C disease pathogenesis. PMID:22296994

Garcia, J P; Beingesser, J; Fisher, D J; Sayeed, S; McClane, B A; Posthaus, H; Uzal, F A

2012-01-11

173

Clostridium perfringens in poultry: an emerging threat for animal and public health  

Microsoft Academic Search

The incidence of Clostridiumperfringens-associated necrotic enteritis in poultry has increased in countries that stopped using antibiotic growth promoters. Necrotic enteritis and the subclinical form of C. perfringens infection in poultry are caused by C. perfringens type A, producing the alpha toxin, and to a lesser extent type C, producing both alpha toxin and beta toxin. Some strains of C. perfringens

Filip Van Immerseel; Jeroen De Buck; Frank Pasmans; Gerard Huyghebaert; Freddy Haesebrouck; Richard Ducatelle

2004-01-01

174

The effect of calcium and sodium lactates on growth from spores of Bacillus cereus and Clostridium perfringens in a ‘sous-vide’ beef goulash under temperature abuse  

Microsoft Academic Search

The effect of calcium and sodium lactates on growth from spores of Bacillus cereus and Clostridium perfringens at three different concentrations (0, 1.5 and 3% w\\/w) and at different temperatures (10, 15 and 20°C for B. cereus and 15, 20 and 25°C for C. perfringens) was investigated, using beef goulash as a model system for pasteurised vacuum-packaged convenience foods. Calcium

Necla Aran

2001-01-01

175

Collagenase gene ( colA) is located in the 3?-flanking region of the perfringolysin O ( pfoA) locus in Clostridium perfringens  

Microsoft Academic Search

The 3?-flanking region of the ?-galactosidase gene (pbg), which is located downstream of the perfringolysin O gene (pfoA), and the 5?-flanking region of the collagenase gene (colA) of Clostridium perfringens strains NCTC8237 and 13, respectively, were analyzed. Southern analysis revealed that the colA gene is located 6.5 kb downstream of the pbg gene in the chromosome of C. perfringens. Sequence

Kaori Ohtani; Mayumi Bando; Tint Swe; Sayera Banu; Misari Oe; Hideo Hayashi; Tohru Shimizu

1997-01-01

176

Clostridium perfringens Iota Toxin: Binding Studies and Characterization of Cell Surface Receptor by Fluorescence-Activated Cytometry  

PubMed Central

The binding characteristics of iota toxin, a binary enterotoxin produced by Clostridium perfringens type E, were studied by fluorescence-activated cytometry. The proteolytically activated binding component of iota toxin, iota b (Ib), bound to various cell types when incubated at 4, 25, or 37°C for 10 min. The binding of Ib was inhibited by antisera against C. perfringens type E or Clostridium spiroforme culture supernatants, but not C. perfringens types C or D. Pretreatment of Vero cells with glycosidases or lectins did not affect Ib interactions, while pronase effectively prevented Ib binding to the cell surface. The Ib protomer (Ibp) bound to the cell surface, but trypsinization of Ibp was necessary for docking of the ADP-ribosylating component, iota a (Ia). Ia attached to cell-bound Ib within 10 min at 37°C, but surface levels of Ia decreased 90% after 30 min and were undetectable by 60 min. Detectable surface levels of Ib also diminished over time, and Western blot analysis suggested internalization or embedment of Ib into the membrane.

Stiles, Bradley G.; Hale, Martha L.; Marvaud, Jean-Christophe; Popoff, Michel R.

2000-01-01

177

Clostridium perfringens in apheresis platelets: an unusual contaminant underscores the importance of clinical vigilance for septic transfusion reactions.  

PubMed

BACKGROUND: Posttransfusion sepsis is typically caused by aerobic bacteria in apheresis platelets (PLTs) that escape detection by routine quality control cultures performed on every donation before components are distributed. We report the first case to implicate an anaerobic isolate, Clostridium perfringens, in apheresis PLTs and investigate its detection in vitro by approved tests. STUDY DESIGN AND METHODS: The C.?perfringens strain was inoculated at high (10-100 colony-forming units [CFUs]/mL) or low (1-10 CFUs/mL) concentrations into apheresis PLTs and evaluated for growth over 5 to 7 days by qualitative plate cultures, culture-based assays (BacT/ALERT 3D), and rapid (PLT PGD) tests. RESULTS: C.?perfringens grew in only 3 of 8 apheresis PLT units after inoculation at either high (2 units) or low (1 unit) concentrations. The PGD test detected the isolate after 5 days in 1 unit with 4.7?×?10(5) CFUs/mL but failed at five other time points in units with greater than 10(5) CFUs/mL. CONCLUSION: C.?perfringens demonstrated variable growth in spiked PLTs and was not consistently detected by a rapid test even when high levels of contamination were present. The case underscores the importance of direct observation during transfusion, appropriate clinical management, and immediate reporting of suspected septic reactions to the blood center. PMID:23772803

Eder, Anne F; Meena-Leist, Claire E; Hapip, Cheryl A; Dy, Beth A; Benjamin, Richard J; Wagner, Stephen J

2013-06-17

178

Clostridium perfringens Enterotoxin Fragment Removes Specific Claudins from Tight Junction Strands  

PubMed Central

Claudins, comprising a multigene family, constitute tight junction (TJ) strands. Clostridium perfringens enterotoxin (CPE), a single ?35-kD polypeptide, was reported to specifically bind to claudin-3/RVP1 and claudin-4/CPE-R at its COOH-terminal half. We examined the effects of the COOH-terminal half fragment of CPE (C-CPE) on TJs in L transfectants expressing claudin-1 to -4 (C1L to C4L, respectively), and in MDCK I cells expressing claudin-1 and -4. C-CPE bound to claudin-3 and -4 with high affinity, but not to claudin-1 or -2. In the presence of C-CPE, reconstituted TJ strands in C3L cells gradually disintegrated and disappeared from their cell surface. In MDCK I cells incubated with C-CPE, claudin-4 was selectively removed from TJs with its concomitant degradation. At 4 h after incubation with C-CPE, TJ strands were disintegrated, and the number of TJ strands and the complexity of their network were markedly decreased. In good agreement with the time course of these morphological changes, the TJ barrier (TER and paracellular flux) of MDCK I cells was downregulated by C-CPE in a dose-dependent manner. These findings provided evidence for the direct involvement of claudins in the barrier functions of TJs.

Sonoda, Noriyuki; Furuse, Mikio; Sasaki, Hiroyuki; Yonemura, Shigenobu; Katahira, Jun; Horiguchi, Yasuhiko; Tsukita, Shoichiro

1999-01-01

179

In-vitro antimicrobial susceptibility of Clostridium perfringens from commercial turkey and broiler chicken origin.  

PubMed

The minimum inhibitory concentrations (MIC) of eight antibiotics and two anticoccidial agents were determined for Clostridium perfringens strains isolated from 26 commercial broiler farms and 22 commercial turkey farms. Isolates were obtained from the intestines of birds on the farm or as the processing plant using standard culture and identification techniques. The microbroth dilution test was used to determine the MIC for each compound. Most isolates from chickens had MICs in the range of 2-16 mg/L for tilmicosin, tylosin and virginiamycin, whereas the MICs for avilamycin, avoparcin, monensin, narasin and penicillin were < or = 1 mg/L. Most strains from chickens had high MICs (> or = 64 mg/L) and appeared to be resistant to bacitracin and lincomycin. Most turkey isolates had MICs in the range of 2-16 mg/L for bacitracin, tilmicosin, tylosin and virginiamycin, with strains exhibiting MICs < or = 1 mg/L for avilamycin, avoparcin, monensin, narasin and penicillin. Several turkey isolates had MICs > or = 64 mg/L to lincomycin. No attempt was made to associate farm usage of a particular antibiotic to the antibiograms. PMID:9057262

Watkins, K L; Shryock, T R; Dearth, R N; Saif, Y M

1997-02-01

180

Molecular basis for the pathological actions of Clostridium perfringens iota toxin.  

PubMed Central

Clostridium perfringens type E iota toxin is composed of two separate and independent polypeptide chains that act synergistically in mouse lethal assays. The light chain is an enzyme that mono(ADP-ribosyl)ates certain amino acids. The enzyme displays substantial activity when homopoly-L-arginine is used as a substrate, but it shows little activity when polyasparagine, polylysine or polyglutamic acid are used. In keeping with the properties of an ADP-ribosylating enzyme, the toxin possesses the following characteristics. It produces incorporation of radioactivity into polyarginine when adenine-labeled NAD is used, but radioactivity is not incorporated when nicotinamide-labeled NAD is used. Irrespective of labeling, enzymatic activity is accompanied by the release of free nicotinamide. After incorporation of ADP-ribose groups into polyarginine, enzymatic and chemical techniques can be used to release the incorporated material. Snake venom phosphodiesterase releases mainly AMP; hydroxylamine releases AMP and ADP-ribose. The heavy chain of iota toxin has little or no enzyme activity, and it does not substantially affect the enzyme activity of the light chain. The heavy chain may be a binding component that directs the toxin to vulnerable cells. The data suggest that iota toxin is a representative of a novel class of ADP-ribosylating toxins.

Simpson, L L; Stiles, B G; Zepeda, H H; Wilkins, T D

1987-01-01

181

Pyridoxal phosphate-sensitized photoinactivation of glutamate decarboxylase from Clostridium perfringens  

PubMed Central

1. l-Glutamate decarboxylase (EC 4.1.1.15) from Clostridium perfringens was inactivated by exposure to visible light at pH6.2. 2. Inactivation does not occur at pH4.6 or in the absence of bound pyridoxal phosphate. 3. On prolonged photo-oxidation six histidine residues per molecule of enzyme were destroyed. 4. The loss of six cysteine residues per molecule occurred both in irradiated samples and in controls oxygenated in the dark. 5. This dark-oxidation of cysteine residues is apparently required before the photo-oxidation process. 6. The absorbance, fluorescence and circular-dichroism properties of the enzyme as well as its elution volume during Sephadex gel-filtration were unaffected by prolonged irradiation. 7. However, an apparently homogeneous product of photo-oxidation could be separated from the control enzyme by ion-exchange chromatography. 8. The Km for l-glutamate was unchanged in an irradiated sample retaining 22% of control activity. 9. These data and the catalytic role of imidazole residues at the active sites of amino acid decarboxylases are discussed.

Cozzani, Ivo; Santoni, Costantino; Jori, Giulio; Gennari, Giorgio; Tamburro, Antonio Mario

1974-01-01

182

Hemorrhagic enterocolitis and death in two felines (Panthera tigris altaica and Panthera leo) associated with Clostridium perfringens type A.  

PubMed

Severe hemorrhagic enterocolitis was observed in a Siberian tiger (Panthera tigris altaica) and a lion (Panthera leo). Both animals developed acute depression, anorexia, and bloody diarrhea several days before death. Small and large intestines were diffusely congested, edematous, necrotic, and filled with hemorrhagic fluid, and mesenteric lymph nodes were enlarged and congested. Pure and abundant growth of gram-positive bacilli was obtained in culture under anaerobic conditions from the livers of both felines. Identification of highly virulent Clostridium perfringens Type A was based on pathologic lesions, hemolytic patterns, morphologic structure, and polymerase chain reaction. Animal inoculation assays indicated that C. perfringens Type A played an important role in the pathogenesis of both felines. PMID:22779248

Zhang, Yanlong; Hou, Zhijun; Ma, Jianzhang

2012-06-01

183

In vitro tests for the measurement of clostridial toxins, toxoids and antisera. II. Titration of Clostridium perfringens toxins and antitoxins in cell culture.  

PubMed

The usefulness of cytopathic indicators for the titration of Cl perfringens beta and epsilon toxins has been investigated. Neutralization experiments with monoclonal antibodies have shown that the entities responsible for the lethal and dermonecrotic effects of Cl perfringens beta toxin preparations are identical. However, the cytopathic effects of the same preparations are caused by other entities. Therefore, titrations based upon lethal and dermonecrotic indicators of beta toxin are equally valid but those based on cytopathic effects are not. Similar experiments with Cl perfringens epsilon preparations have shown that their lethal, dermonecrotic and cytopathic activities are all caused by the same entity. It follows that all three activities can be valid indicators for toxin neutralization tests. Cell culture titrations of Cl perfringens epsilon antitoxin performed on rabbit sera at the levels of test prescribed by the European Pharmacopoeia have produced consistent results which agree closely with the dermonecrotic test. This test has, in turn, been shown to reflect the results of the mouse lethal test accurately. Titrations of cattle and sheep sera at lower levels of test have also produced results in close agreement with the in vivo test. It is concluded that cell culture titration offers a valid in vitro alternative to the use of mouse lethal and guinea-pig dermonecrotic indicators for the titration of sera generated in the course of potency tests and field trials of Cl perfringens epsilon vaccines. PMID:2285500

Knight, P A; Queminet, J; Blanchard, J H; Tilleray, J H

1990-10-01

184

Multiplex PCR assay for detection of Clostridium perfringens in feces and intestinal contents of pigs and in swine feed.  

PubMed

A multiplex polymerase chain reaction (PCR) assay, developed to detect the alpha-toxin and enterotoxin genes (cpa and cpe, respectively) of Clostridium perfringens, was used to identify enterotoxigenic isolates of this organism from feces and intestinal contents of pigs and from feed samples from pig farms in Iowa. The organism was grown on tryptose-sulfite-cycloserine (TSC) agar, TSC agar without egg-yolk, sheep blood agar, or in brain heart infusion broth or cooked meat medium. DNA was extracted by boiling and the PCR assay was carried out using reagents from a commercial kit. The 319 bp amplification product of cpa and the 364 bp product of cpe were visualized under UV light after electrophoresis in a 2% agarose gel containing ethidium bromide. The average sensitivity of the assay, determined on artificially contaminated feces, was 9.2 x 10(4) colony forming units per gram. Assay of 97 isolates from feces and intestinal contents revealed cpa in 89, but all were negative for cpe. While 28% of the 442 total samples cultured yielded C. perfringens, only 5% of 298 fecal or intestinal contents samples were positive upon direct examination by the PCR assay. Ninety-one and eight-tenths % of isolates with the phenotype of C. perfringens were cpa positive by PCR. Forty-three percent of feed samples were culture positive, while 48.3% were PCR positive for cpa. None of these were cpe positive. We conclude that PCR is a useful assay for rapid detection of C. perfringens in feed, and for confirmation of the identity of isolates presumed to be C. perfringens. PMID:9810619

Kanakaraj, R; Harris, D L; Songer, J G; Bosworth, B

1998-08-28

185

Comparative genomics of four closely related Clostridium perfringens bacteriophages reveals variable evolution among core genes with therapeutic potential  

Microsoft Academic Search

Background  Because biotechnological uses of bacteriophage gene products as alternatives to conventional antibiotics will require a thorough\\u000a understanding of their genomic context, we sequenced and analyzed the genomes of four closely related phages isolated from\\u000a Clostridium perfringens, an important agricultural and human pathogen.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Phage whole-genome tetra-nucleotide signatures and proteomic tree topologies correlated closely with host phylogeny. Comparisons\\u000a of our phage genomes

Brian B Oakley; Eldin Talundzic; Cesar A Morales; Kelli L Hiett; Gregory R Siragusa; Nikolay V Volozhantsev; Bruce S Seal

2011-01-01

186

Tetracycline and penicillin resistant Clostridium perfringens isolated from the fangs and venom glands of Loxosceles laeta: its implications in loxoscelism treatment.  

PubMed

The venom of Loxosceles spiders produces severe dermonecrotic damage, intravascular hemolysis, systemic alterations and risk of death. Clostridium perfringens is present in the microbial flora of the fangs and venom glands of Loxosceles intermedia. Its inoculation with the venom may infect the wound site and exacerbate the dermonecrotic damage. This anaerobic bacterium is widely distributed in nature and capable of damage with similar characteristics and severity to the spider venom. In this study we isolated and characterized species of Clostridium from the fangs and venom glands of Loxosceles laeta, including C. perfringens. The sensitivity patterns of different isolates of C. perfringens were evaluated by minimum inhibitory concentration against penicillin, ampicillin, erythromycin, gentamicin, chloramphenicol, clindamycin and tetracycline, under anaerobic conditions, using the method of microdilution in broth. Strain C. perfringens H28 showed resistance to penicillin, ampicillin, tetracycline and chloramphenicol. Resistance to penicillin and ampicillin was mediated by beta-lactamase. In vivo evaluation of dermonecrosis in rabbits using L. laeta venom co-inoculated with isolate C. perfringens H28 produced an increase in the area of dermonecrotic lesions in the presence of penicillin and tetracycline, but not with gentamicin. Antibiotic therapy Loxosceles poisoning should be re-evaluated, considering the existence of multi-resistant strains of C. perfringens. PMID:20600224

Catalán, A; Espoz, M C; Cortés, W; Sagua, H; González, J; Araya, J E

2010-06-25

187

Clostridium perfringens Alpha-toxin Recognizes the GM1a-TrkA Complex*  

PubMed Central

Clostridium perfringens alpha-toxin is the major virulence factor in the pathogenesis of gas gangrene. Alpha-toxin is a 43-kDa protein with two structural domains; the N-domain contains the catalytic site and coordinates the divalent metal ions, and the C-domain is a membrane-binding site. The role of the exposed loop region (72–93 residues) in the N-domain, however, has been unclear. Here we show that this loop contains a ganglioside binding motif (H … SXWY … G) that is the same motif seen in botulinum neurotoxin and directly binds to a specific conformation of the ganglioside Neu5Ac?2-3(Gal?1-3GalNAc?1-4)Gal?1-4Glc?1Cer (GM1a) through a carbohydrate moiety. Confocal microscopy analysis using fluorescently labeled BODIPY-GM1a revealed that the toxin colocalized with GM1a and induced clustering of GM1a on the cell membranes. Alpha-toxin was only slightly toxic in ?1,4-N-acetylgalactosaminyltransferase knock-out mice, which lack the a-series gangliosides that contain GM1a, but was highly toxic in ?2,8-sialyltransferase knock-out mice, which lack both b-series and c-series gangliosides, similar to the control mice. Moreover, experiments with site-directed mutants indicated that Trp-84 and Tyr-85 in the exposed alpha-toxin loop play an important role in the interaction with GM1a and subsequent activation of TrkA. These results suggest that binding of alpha-toxin to GM1a facilitates the activation of the TrkA receptor and induces a signal transduction cascade that promotes the release of chemokines. Therefore, we conclude that GM1a is the primary cellular receptor for alpha-toxin, which can be a potential target for drug developed against this pathogen.

Oda, Masataka; Kabura, Michiko; Takagishi, Teruhisa; Suzue, Ayaka; Tominaga, Kaori; Urano, Shiori; Nagahama, Masahiro; Kobayashi, Keiko; Furukawa, Keiko; Furukawa, Koichi; Sakurai, Jun

2012-01-01

188

Clostridium perfringens alpha-toxin recognizes the GM1a-TrkA complex.  

PubMed

Clostridium perfringens alpha-toxin is the major virulence factor in the pathogenesis of gas gangrene. Alpha-toxin is a 43-kDa protein with two structural domains; the N-domain contains the catalytic site and coordinates the divalent metal ions, and the C-domain is a membrane-binding site. The role of the exposed loop region (72-93 residues) in the N-domain, however, has been unclear. Here we show that this loop contains a ganglioside binding motif (H … SXWY … G) that is the same motif seen in botulinum neurotoxin and directly binds to a specific conformation of the ganglioside Neu5Ac?2-3(Gal?1-3GalNAc?1-4)Gal?1-4Glc?1Cer (GM1a) through a carbohydrate moiety. Confocal microscopy analysis using fluorescently labeled BODIPY-GM1a revealed that the toxin colocalized with GM1a and induced clustering of GM1a on the cell membranes. Alpha-toxin was only slightly toxic in ?1,4-N-acetylgalactosaminyltransferase knock-out mice, which lack the a-series gangliosides that contain GM1a, but was highly toxic in ?2,8-sialyltransferase knock-out mice, which lack both b-series and c-series gangliosides, similar to the control mice. Moreover, experiments with site-directed mutants indicated that Trp-84 and Tyr-85 in the exposed alpha-toxin loop play an important role in the interaction with GM1a and subsequent activation of TrkA. These results suggest that binding of alpha-toxin to GM1a facilitates the activation of the TrkA receptor and induces a signal transduction cascade that promotes the release of chemokines. Therefore, we conclude that GM1a is the primary cellular receptor for alpha-toxin, which can be a potential target for drug developed against this pathogen. PMID:22847002

Oda, Masataka; Kabura, Michiko; Takagishi, Teruhisa; Suzue, Ayaka; Tominaga, Kaori; Urano, Shiori; Nagahama, Masahiro; Kobayashi, Keiko; Furukawa, Keiko; Furukawa, Koichi; Sakurai, Jun

2012-07-30

189

Functional Identification of Conjugation and Replication Regions of the Tetracycline Resistance Plasmid pCW3 from Clostridium perfringens  

PubMed Central

Clostridium perfringens causes fatal human infections, such as gas gangrene, as well as gastrointestinal diseases in both humans and animals. Detailed molecular analysis of the tetracycline resistance plasmid pCW3 from C. perfringens has shown that it represents the prototype of a unique family of conjugative antibiotic resistance and virulence plasmids. We have identified the pCW3 replication region by deletion and transposon mutagenesis and showed that the essential rep gene encoded a basic protein with no similarity to any known plasmid replication proteins. An 11-gene conjugation locus containing 5 genes that encoded putative proteins with similarity to proteins from the conjugative transposon Tn916 was identified, although the genes’ genetic arrangements were different. Functional genetic studies demonstrated that two of the genes in this transfer clostridial plasmid (tcp) locus, tcpF and tcpH, were essential for the conjugative transfer of pCW3, and comparative analysis confirmed that the tcp locus was not confined to pCW3. The conjugation region was present on all known conjugative plasmids from C. perfringens, including an enterotoxin plasmid and other toxin plasmids. These results have significant implications for plasmid evolution, as they provide evidence that a nonreplicating Tn916-like element can evolve to become the conjugation locus of replicating plasmids that carry major virulence genes or antibiotic resistance determinants.

Bannam, Trudi L.; Teng, Wee Lin; Bulach, Dieter; Lyras, Dena; Rood, Julian I.

2006-01-01

190

Acid phosphatase test proves superior to standard phenotypic identification procedure for Clostridium perfringens strains isolated from water  

PubMed Central

Clostridium perfringens is used as an indicator for persistent faecal pollution as well as to monitor the efficacy of water treatment processes. For these purposes, differentiation between C. perfringens and other Clostridia is essential and is routinely carried out by phenotypic standard tests as proposed in the ISO/CD 6461-2:2002 (ISO_LGMN: lactose fermentation, gelatine liquidation, motility and nitrate reduction). Because the ISO_LGMN procedure is time consuming and labour intensive, the acid phosphatase test was investigated as a possible and much more rapid alternative method for confirmation. The aim of our study was to evaluate and compare confirmation results obtained by these two phenotypic methods using genotypically identified strains, what to our knowledge has not been accomplished before. For this purpose, a species specific PCR method was selected based on the results received for type strains and genotypically characterised environmental strains. For the comparative investigation type strains as well as presumptive C. perfringens isolates from water and faeces samples were used. The acid phosphatase test revealed higher percentage (92%) of correctly identified environmental strains (n = 127) than the ISO_LGMN procedure (83%) and proved to be a sensitive and reliable confirmation method.

Ryzinska-Paier, G.; Sommer, R.; Haider, J.M.; Knetsch, S.; Frick, C.; Kirschner, A.K.T.; Farnleitner, A.H.

2011-01-01

191

Acid phosphatase test proves superior to standard phenotypic identification procedure for Clostridium perfringens strains isolated from water.  

PubMed

Clostridium perfringens is used as an indicator for persistent faecal pollution as well as to monitor the efficacy of water treatment processes. For these purposes, differentiation between C. perfringens and other Clostridia is essential and is routinely carried out by phenotypic standard tests as proposed in the ISO/CD 6461-2:2002 (ISO_LGMN: lactose fermentation, gelatine liquidation, motility and nitrate reduction). Because the ISO_LGMN procedure is time consuming and labour intensive, the acid phosphatase test was investigated as a possible and much more rapid alternative method for confirmation. The aim of our study was to evaluate and compare confirmation results obtained by these two phenotypic methods using genotypically identified strains, what to our knowledge has not been accomplished before. For this purpose, a species specific PCR method was selected based on the results received for type strains and genotypically characterised environmental strains. For the comparative investigation type strains as well as presumptive C. perfringens isolates from water and faeces samples were used. The acid phosphatase test revealed higher percentage (92%) of correctly identified environmental strains (n=127) than the ISO_LGMN procedure (83%) and proved to be a sensitive and reliable confirmation method. PMID:21872622

Ryzinska-Paier, G; Sommer, R; Haider, J M; Knetsch, S; Frick, C; Kirschner, A K T; Farnleitner, A H

2011-08-18

192

The synergistic necrohemorrhagic action of Clostridium perfringens perfringolysin and alpha toxin in the bovine intestine and against bovine endothelial cells  

PubMed Central

Bovine necrohemorrhagic enteritis is a major cause of mortality in veal calves. Clostridium perfringens is considered as the causative agent, but there has been controversy on the toxins responsible for the disease. Recently, it has been demonstrated that a variety of C. perfringens type A strains can induce necrohemorrhagic lesions in a calf intestinal loop assay. These results put forward alpha toxin and perfringolysin as potential causative toxins, since both are produced by all C. perfringens type A strains. The importance of perfringolysin in the pathogenesis of bovine necrohemorrhagic enteritis has not been studied before. Therefore, the objective of the current study was to evaluate the role of perfringolysin in the development of necrohemorrhagic enteritis lesions in calves and its synergism with alpha toxin. A perfringolysin-deficient mutant, an alpha toxin-deficient mutant and a perfringolysin alpha toxin double mutant were less able to induce necrosis in a calf intestinal loop assay as compared to the wild-type strain. Only complementation with both toxins could restore the activity to that of the wild-type. In addition, perfringolysin and alpha toxin had a synergistic cytotoxic effect on bovine endothelial cells. This endothelial cell damage potentially explains why capillary hemorrhages are an initial step in the development of bovine necrohemorrhagic enteritis. Taken together, our results show that perfringolysin acts synergistically with alpha toxin in the development of necrohemorrhagic enteritis in a calf intestinal loop model and we hypothesize that both toxins act by targeting the endothelial cells.

2013-01-01

193

Portrait of an Enzyme, a Complete Structural Analysis of a Multimodular ?-N-Acetylglucosaminidase from Clostridium perfringens*S?  

PubMed Central

Common features of the extracellular carbohydrate-active virulence factors involved in host-pathogen interactions are their large sizes and modular complexities. This has made them recalcitrant to structural analysis, and therefore our understanding of the significance of modularity in these important proteins is lagging. Clostridium perfringens is a prevalent human pathogen that harbors a wide array of large, extracellular carbohydrate-active enzymes and is an excellent and relevant model system to approach this problem. Here we describe the complete structure of C. perfringens GH84C (NagJ), a 1001-amino acid multimodular homolog of the C. perfringens ?-toxin, which was determined using a combination of small angle x-ray scattering and x-ray crystallography. The resulting structure reveals unprecedented insight into how catalysis, carbohydrate-specific adherence, and the formation of molecular complexes with other enzymes via an ultra-tight protein-protein interaction are spatially coordinated in an enzyme involved in a host-pathogen interaction.

Ficko-Blean, Elizabeth; Gregg, Katie J.; Adams, Jarrett J.; Hehemann, Jan-Hendrik; Czjzek, Mirjam; Smith, Steven P.; Boraston, Alisdair B.

2009-01-01

194

Occurrence of Clostridium perfringens in the broiler chicken processing plant as determined by recovery in iron milk medium.  

PubMed

Over 30 years ago, Clostridium perfringens was reported as a contaminant of the processing plant and processed carcasses of broiler chickens. Poultry processing procedures and methods for detecting C. perfringens have changed since that time. Therefore, a study was conducted to determine the incidence and numbers of C. perfringens in the water of the scald tank, the water of the chill tank, and the rinse water of the processed carcasses from modern broiler chicken processing plants. In trial 1, collected samples were inoculated into iron milk medium (IMM) and incubated at 46 degrees C for 18 h (the traditional method) or at 37 degrees C for 3 h followed by incubation at 46 degrees C for 15 h (an injury recovery method). Each of three preselected broiler chicken flocks from two integrators were the first processed for that processing shift. The overall incidence of confirmed C. perfringens in samples associated with the three flocks was 40% of postprocessing scald water samples, 13% of preprocessing chill water samples, 13% of postprocessing chill water samples, and 19% of carcass rinses. The incidence of C. perfringens in samples incubated in IMM using the injury recovery procedure was significantly higher than in samples incubated in IMM by the traditional method, but only when all samples associated with the three flocks were pooled. In trial 2, water samples from each tank of a three-tank counterflow scalder, water samples from the prechill and chill tank, and samples of carcass rinses were collected in the middle of a processing shift during multiple visits to a processing plant. Samples were inoculated into IMM with neomycin and polymyxin B sulfate (IMMA) and incubated using the traditional and injury recovery procedures. The incidence of C. perfringens in water samples was 100% from scald tank 1, 100% from scald tank 2, 100% from scald tank 3, 88% from the prechill tank, and 63% from the chill tank. The incidence in carcass rinse samples was 67%. The mean most probably number (MPN) of C. perfringens for contaminated samples decreased from log10 5.07/100 ml of water in scald tank 1 to log10 1.26/100 ml of water in the chill tank. The mean MPN in carcass rinse samples was log10 1.20 C. perfringens per 100 ml. The incidence and mean MPN of C. perfringens in these samples after heat shock at 75 degrees C for 20 min was somewhat less, but high enough to indicate that much of the contamination arises from heat-resistant spores of this organism. In trial 2, there were no differences in incidence and MPN of C. perfringens in samples incubated in IMMA with the traditional method or the injury recovery method. PMID:11770623

Craven, S E

2001-12-01

195

PREDICTIVE MODEL FOR GROWTH OF CLOSTRIDIUM PERFRINGENS IN ROAST BEEF DURING COOLING AND INHIBITION OF SPORE GERMINATION AND OUTGROWTH BY SALTS OF ORGANIC ACIDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Germination and outgrowth of Clostridium perfringens spores in roast beef during chilling was studied following simulated cooling schedules normally used in the processed meat industry. Beef top rounds were formulated to contain a marinade (finished product concentrations of salt, 1%; potassium tet...

196

THE EFFECT OF GRAPEFRUIT EXTRACT AND TEMPERATURE ABUSE ON GROWTH OF CLOSTRIDIUM PERFRINGENS FROM SPORE INOCULA IN MARINATED, SOUS-VIDE CHICKEN PRODUCTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Clostridium perfringens growth from a spore inoculum was investigated in vacuum-packaged, cook-in-bag, marinated chicken breast that included additional 1.0% NaCl. The packages were processed to an internal temperature of 71.1 deg C, ice chilled and stored at various temperatures. The total C. per...

197

The Effect of Two Different Blends of Essential Oil Components on the Proliferation of Clostridium perfringens in the Intestines of Broiler Chickens  

Microsoft Academic Search

The effect of 2 different blends of essential oils on Clostridium perfringens (Cp) in the intestine and feces of broiler chickens was tested in 6 field trials for each blend. One hundred parts per million of the blends were mixed in a commercial corn-based diet throughout the entire growing period for experimental flocks. Sam- ples from the jejunum, cecum, cloaca,

P. Mitsch; K. Zitterl-Eglseer; B. Kohler; C. Gabler; R. Losa; I. Zimpernik

198

Inhibition of clostridium perfringens spore germination and outgrowth by buffered vinegar and lemon juice concentrate during chilling.....of ground turkey road containing minimal ingredients  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of Clostridium perfringens spore germination and outgrowth in ground turkey roast containing minimal ingredients (salt and sugar), by buffered vinegar (MoStatin V) and a blend (buffered) of lemon juice concentrate and vinegar (MoStatin LV) was evaluated. Ground turkey roast was formulat...

199

Inhibition of Clostridium perfringens spore germination and outgrowth by lemon juice and vinegar product in reduced NaCl roast beef  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inhibition of Clostridium perfringens spore germination and outgrowth in reduced sodium roast beef by a blend of buffered lemon juice concentrate and vinegar (MoStatin LV) during abusive exponential cooling was evaluated. Roast beef containing salt (NaCl; 1, 1.5, or 2%, wt/wt), blend of sodium pyro-...

200

ATTEMPTS TO ISOLATE NATURALLY OCCURRING CAMPYLOBACTER, SALMONELLA AND CLOSTRIDIUM PERFRINGENS FROM THE DUCTUS DEFERENS, TESTES AND CECA OF COMMERCIAL BROILER BREEDER ROOSTERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent studies have shown a significant presence of Campylobacter in the semen of mid-life and late-life roosters. The present study was done to determine if several foodborne pathogens (Campylobacter, Salmonella, Clostridium perfringens) could be isolated from the ductus deferens, testes and ceca ...

201

The effect of artemisia annua on broiler performance, intestinal microbiota and on the course of a clostridium perfringens infection applying a necrotic enteritis disease model  

Microsoft Academic Search

The aerial parts of the plant Artemisia annua (A. 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

Ricarda Margarete Engberg; Kai Grevsen; Elise Ivarsen; Xavier Fretté; Lars Porskjær Christensen; Ole Højberg; Bent Borg Jensen; Nuria Canibe

2012-01-01

202

A Rare Case of Secondary Bacterial Peritonitis from Clostridium perfringens in an Adult Patient with Noncirrhotic Ascites and a Krukenberg Tumor: Report of a Case  

PubMed Central

Secondary bacterial peritonitis, in comparison to spontaneous, presents with a surgically treatable intraabdominal source for infection such as a gastrointestinal perforation or abscess and is nearly always polymicrobial. We present a rare case of secondary bacterial peritonitis from Clostridium perfringens in an adult patient with noncirrhotic ascites and a Krukenberg tumor.

Kelley, Scott R.; Kerlakian, George M.

2011-01-01

203

Type IV Pili and the CcpA Protein Are Needed for Maximal Biofilm Formation by the Gram-Positive Anaerobic Pathogen Clostridium perfringens  

Microsoft Academic Search

The predominant organizational state of bacteria in nature is biofilms. Biofilms have been shown to increase bacterial resistance to a variety of stresses. We demonstrate for the first time that the anaerobic gram-positive pathogen Clostridium perfringens forms biofilms. At the same concentration of glucose in the medium, optimal biofilm formation depended on a functional CcpA protein. While the ratio of

John J. Varga; Blair Therit; Stephen B. Melville

2008-01-01

204

DYNAMIC COMPUTER SIMULATION OF THE MULTIPLICATION OF CLOSTRIDIUM PERFRINGENS IN COOKED GROUND BEEF  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study was to develop a computer simulation algorithm to dynamically estimate and predict the growth of C. perfringens spores in cooked ground beef. The computational algorithm was based on the implicit form of the Gompertz model, the growth kinetics of C. perfringens in cooed ...

205

A wide variety of Clostridium perfringens type A food-borne isolates that carry a chromosomal cpe gene belong to one multilocus sequence typing cluster.  

PubMed

Of 98 suspected food-borne Clostridium perfringens isolates obtained from a nationwide survey by the Food and Consumer Product Safety Authority in The Netherlands, 59 strains were identified as C. perfringens type A. Using PCR-based techniques, the cpe gene encoding enterotoxin was detected in eight isolates, showing a chromosomal location for seven isolates and a plasmid location for one isolate. Further characterization of these strains by using (GTG)(5) fingerprint repetitive sequence-based PCR analysis distinguished C. perfringens from other sulfite-reducing clostridia but did not allow for differentiation between various types of C. perfringens strains. To characterize the C. perfringens strains further, multilocus sequence typing (MLST) analysis was performed on eight housekeeping genes of both enterotoxic and non-cpe isolates, and the data were combined with a previous global survey covering strains associated with food poisoning, gas gangrene, and isolates from food or healthy individuals. This revealed that the chromosomal cpe strains (food strains and isolates from food poisoning cases) belong to a distinct cluster that is significantly distant from all the other cpe plasmid-carrying and cpe-negative strains. These results suggest that different groups of C. perfringens have undergone niche specialization and that a distinct group of food isolates has specific core genome sequences. Such findings have epidemiological and evolutionary significance. Better understanding of the origin and reservoir of enterotoxic C. perfringens may allow for improved control of this organism in foods. PMID:22865060

Xiao, Yinghua; Wagendorp, Arjen; Moezelaar, Roy; Abee, Tjakko; Wells-Bennik, Marjon H J

2012-08-03

206

A Wide Variety of Clostridium perfringens Type A Food-Borne Isolates That Carry a Chromosomal cpe Gene Belong to One Multilocus Sequence Typing Cluster  

PubMed Central

Of 98 suspected food-borne Clostridium perfringens isolates obtained from a nationwide survey by the Food and Consumer Product Safety Authority in The Netherlands, 59 strains were identified as C. perfringens type A. Using PCR-based techniques, the cpe gene encoding enterotoxin was detected in eight isolates, showing a chromosomal location for seven isolates and a plasmid location for one isolate. Further characterization of these strains by using (GTG)5 fingerprint repetitive sequence-based PCR analysis distinguished C. perfringens from other sulfite-reducing clostridia but did not allow for differentiation between various types of C. perfringens strains. To characterize the C. perfringens strains further, multilocus sequence typing (MLST) analysis was performed on eight housekeeping genes of both enterotoxic and non-cpe isolates, and the data were combined with a previous global survey covering strains associated with food poisoning, gas gangrene, and isolates from food or healthy individuals. This revealed that the chromosomal cpe strains (food strains and isolates from food poisoning cases) belong to a distinct cluster that is significantly distant from all the other cpe plasmid-carrying and cpe-negative strains. These results suggest that different groups of C. perfringens have undergone niche specialization and that a distinct group of food isolates has specific core genome sequences. Such findings have epidemiological and evolutionary significance. Better understanding of the origin and reservoir of enterotoxic C. perfringens may allow for improved control of this organism in foods.

Xiao, Yinghua; Wagendorp, Arjen; Moezelaar, Roy; Abee, Tjakko

2012-01-01

207

Immunization against Clostridium perfringens cells elicits protection against Clostridium tetani in mouse model: identification of cross-reactive proteins using proteomic methodologies  

PubMed Central

Background Clostridium tetani and Clostridium perfringens are among the medically important clostridial pathogens causing diseases in man and animals. Several homologous open reading frames (ORFs) have been identified in the genomes of the two pathogens by comparative genomic analysis. We tested a likelihood of extensive sharing of common epitopes between homologous proteins of these two medically important pathogens and the possibility of cross-protection using active immunization. Results Eight predominant cross-reactive spots were identified by mass spectrometry and had hits in the C. tetani E88 proteome with significant MOWSE scores. Most of the cross-reactive proteins of C. tetani shared 65–78% sequence similarity with their closest homologues in C. perfringens ATCC13124. Electron transfer flavoprotein beta-subunit (CT3) was the most abundant protein (43.3%), followed by methylaspartate ammonia-lyase (36.8%) and 2-phosphoglycerate dehydratase (35.6%). All the proteins were predicted to be cytoplasmic by PSORT protein localization algorithm. Active immunization with C. perfringens whole cells elicited cross-protective immunity against C. tetani infection in a mouse model. Conclusion Most of the dominant cross-reactive proteins of C. tetani belonged to the cluster of orthologous group (COG) functional category, either of posttranslational modification, protein turnover, and chaperones (O) or energy production and conversion (C). The homologs of the identified proteins have been shown to play role in pathogenesis in other Gram-positive pathogenic bacteria. Our findings provide basis for the search of potential vaccine candidates with broader coverage, encompassing more than one pathogenic clostridial species.

Alam, Syed Imteyaz; Bansod, Sunita; Singh, Lokendra

2008-01-01

208

Development of multiplex PCR for the detection of total coliform bacteria for Escherichia coli and Clostridium perfringens in drinking water.  

PubMed

Multiplex PCR amplification of lacZ, uidA and plc genes was developed for the simultaneous detection of total coliform bacteria for Escherichia coli and Clostridium perfringens, in drinking water. Detection by agarose gel electrophoresis yielded a band of 876 bp for the lacZ gene of all coliform bacteria; a band of 147 bp for the uidA gene and a band of 876 bp for the lacZ gene of all strains of E. coli; a band of 280 bp for the p/c gene for all strains of C. perfringens; and a negative result for all three genes when tested with other bacteria. The detection limit was 100 pg for E. coli and C. perfringens, and 1 ng for coliform bacteria when measured with purified DNA. This assay was applied to the detection of these bacteria in spiked water samples. Spiked water samples with 0-1,000 CFU/ml of coliform bacteria and/or E. coli and/or C. perfringens were detected by this multiplex PCR after a pre-enrichment step to increase the sensitivity and to ensure that the detection was based on the presence of cultivable bacteria. The result of bacterial detection from the multiplex PCR was comparable with that of a standard plate count on selective medium (p=0.62). When using standard plate counts as a gold standard, the sensitivity for this test was 99.1% (95% CI 95.33, 99.98) and the specificity was 90.9 % (95% CI 75.67, 98.08). Multiplex PCR amplification with a pre-enrichment step was shown to be an effective, sensitive and rapid method for the simultaneous detection of these three microbiological parameters in drinking water. PMID:15906661

Tantawiwat, Suwalee; Tansuphasiri, Unchalee; Wongwit, Waranya; Wongchotigul, Varee; Kitayaporn, Dwip

2005-01-01

209

Use of a mariner-based transposon mutagenesis system to isolate Clostridium perfringens mutants deficient in gliding motility.  

PubMed

Clostridium perfringens is an anaerobic Gram-positive pathogen that causes many human and animal diseases, including food poisoning and gas gangrene. C. perfringens lacks flagella but possesses type IV pili (TFP). We have previously shown that C. perfringens can glide across an agar surface in long filaments composed of individual bacteria attached end to end and that two TFP-associated proteins, PilT and PilC, are needed for this. To discover additional gene products that play a role in gliding, we developed a plasmid-based mariner transposon mutagenesis system that works effectively in C. perfringens. More than 10,000 clones were screened for mutants that lacked the ability to move away from the edge of a colony. Twenty-four mutants (0.24%) were identified that fit the criteria. The genes containing insertions that affected gliding motility fell into nine different categories. One gene, CPE0278, which encodes a homolog of the SagA cell wall-dependent endopeptidase, acquired distinct transposon insertions in two independent mutants. sagA mutants were unable to form filaments due to a complete lack of end-to-end connections essential for gliding motility. Complementation of the sagA mutants with a wild-type copy of the gene restored gliding motility. We constructed an in-frame deletion mutation in the sagA gene and found that this mutant had a phenotype similar to those of the transposon mutants. We hypothesize that the sagA mutant strains are unable to form the molecular complexes which are needed to keep the cells in an end-to-end orientation, leading to separation of daughter cells and the inability to carry out gliding motility. PMID:23204460

Liu, Hualan; Bouillaut, Laurent; Sonenshein, Abraham L; Melville, Stephen B

2012-11-30

210

Comparison of Tn5397 from Clostridium difficile ,T n916 from Enterococcus faecalis and the CW459tet(M) element from Clostridium perfringens shows that they have similar conjugation regions but different insertion and excision modules  

Microsoft Academic Search

Comparative analysis of the conjugative transposons Tn5397 from Clostridium difficile and Tn916 from Enterococcus faecalis, and the CW459tet(M) element from Clostridium perfringens, has revealed that these tetracycline-resistance elements are closely related. All three elements contain the tet(M) resistance gene and have sequence similarity throughout their central region. However, they have very different integration\\/excision modules. Instead of the int and xis

Adam P. Roberts; Priscilla A. Johanesen; Dena Lyras; Peter Mullany; Julian I. Rood

2001-01-01

211

Clostridium perfringens toxin genotypes in the feces of healthy North Americans  

PubMed Central

We investigated the frequency of C. perfringens in the normal fecal flora of healthy North Americans. About half of 43 subjects were colonized with C. perfringens at levels of ~106 cfu/g feces. Only type A strains were recovered. Spores sometimes outnumbered vegetative cells. Several genotypes were found. Some donors carried two genotypes, some only one. We found no alpha, beta2 or enterotoxin in the stools of any donors. Though some isolates carried toxin genes (e.g. cpe and cpb2) on plasmids, we saw no indication that healthy humans are the reservoir for the chromosomally-borne cpe recovered from cases of C. perfringens food poisoning.

Carman, Robert J.; Sayeed, Sameera; Li, Jihong; Genheimer, Christopher W.; Hiltonsmith, Megan F.; Wilkins, Tracy D.; McClane, Bruce A.

2008-01-01

212

Comparative Effects of Osmotic, Sodium Nitrite-Induced, and pH-Induced Stress on Growth and Survival of Clostridium perfringens Type A Isolates Carrying Chromosomal or Plasmid-Borne Enterotoxin Genes  

Microsoft Academic Search

About 1 to 2% of Clostridium perfringens isolates carry the enterotoxin gene (cpe) necessary for causing C. perfringens type A food poisoning. While the cpe gene can be either chromosomal or plasmid borne, food poisoning isolates usually carry a chromosomal cpe gene. Previous studies have linked this association between chromosomal cpe isolates (i.e., C-cpe isolates) and food poisoning, at least

Jihong Li; Bruce A. McClane

2006-01-01

213

Molecular Characterization of Podoviral Bacteriophages Virulent for Clostridium perfringens and Their Comparison with Members of the Picovirinae  

PubMed Central

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 ?CPV4 and ?ZP2, were isolated in the Moscow Region of the Russian Federation while another closely related virus, named ?CP7R, 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 ?CP7R 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 ?29. Whole-genome comparisons supported this relationship, but also indicated that the Russian and USA viruses may be unique members of the sub-family Picovirinae.

Volozhantsev, Nikolay V.; Oakley, Brian B.; Morales, Cesar A.; Verevkin, Vladimir V.; Bannov, Vasily A.; Krasilnikova, Valentina M.; Popova, Anastasia V.; Zhilenkov, Eugeni L.; Garrish, Johnna K.; Schegg, Kathleen M.; Woolsey, Rebekah; Quilici, David R.; Line, J. Eric; Hiett, Kelli L.; Siragusa, Gregory R.; Svetoch, Edward A.; Seal, Bruce S.

2012-01-01

214

Relationship of sporulation, enterotoxin formation, and spoilage during growth of Clostridium perfringens type A in cooked chicken.  

PubMed

Sporulation and enterotoxin formation were determined for 17 strains of Clostridium perfringens type A in autoclaved chicken dark meat and in Duncan-Strong sporulation medium. The mean numbers of heat-resistant spores detected after 24 h at 37 degrees C were log10 1.13 to log10 7.64/ml in Duncan-Strong medium and log10 4.93 to log10 6.59/g in chicken. Of 17 strains, 7 formed enterotoxin in Duncan-Strong culture supernatant (1.0 to 60 microgram/ml) and 8 produced enterotoxin in chicken (0.21 to 24 microgram/g). Additional studies with chicken were conducted with C. perfringens NCTC 8239. With an inoculum of 10(6) cells per g, greater than log10 7.99 vegetative cells per g were detected by 4 h in chicken at 37 degrees C. Heat-resistant spores occurred by 4 and 6 h and enterotoxin occurred by 8 and 6 h in autoclaved chicken dark meat and barbecued chicken drumsticks, respectively. Enterotoxin was detected in autoclaved dark meat after incubation at 45 degrees C for 1.5 h followed by 37 degrees C for 4.5 h, but not after incubation at 45 degrees C for 1.5 to 8 h. With an inoculum of 10(2) cells per g in oven-cooked or autoclaved chicken, greater than log10 8.00 vegetative cells per g were detected by 6 to 8 h at 37 degrees C, heat-resistant spores were detected by 8 h, and enterotoxin was detected by 12 h. A statistical analysis of odor determinants of chicken after growth of C. perfringens indicated that, at the 95% confidence level, the product was considered spoiled (off or unwholesome odor) by the time spores or enterotoxin were formed. PMID:6266336

Craven, S E; Blankenship, L C; McDonel, J L

1981-05-01

215

Detection of toxins A/B and isolation of Clostridium difficile and Clostridium perfringens from dogs in Minas Gerais, Brazil  

PubMed Central

The objective of this study was to detect C. difficile A/B toxins and to isolate strains of C. perfringens and C. difficile from diarrheic and non-diarrheic dogs in Brazil. Stool samples were collected from 57 dogs, 35 of which were apparently healthy, and 22 of which were diarrheic. C. difficile A/B toxins were detected by ELISA, and C. perfringens and C. difficile were identified by multiplex PCR. C. difficile A/B toxins were detected in 21 samples (36.8%). Of these, 16 (76.2%) were from diarrheic dogs, and five (23.8%) were from non-diarrheic dogs. Twelve C. difficile strains (21.1%) were isolated, of which ten were A+B+ and two were A?B?. All non-toxigenic strains were isolated from non-diarrheic animals. The binary toxin gene cdtB was found in one strain, which was A+B+ and was derived from a non-diarrheic dog. C. perfringens strains were isolated from 40 samples (70.2%). Of these, 18 (45%) were from the diarrheic group, and 22 (55%) belonged to the non-diarrheic group. All isolates were classified as C. perfringens type A and there was an association between the detection of the cpe gene and the presence of diarrhea. Interestingly, ten strains (25%) were positive for the presence of the cpb2 gene. The high rate of detection of the A/B toxins in non-diarrheic dogs suggests the occurrence of subclinical disease in dogs or carriage of its toxins without disease. More studies are needed to elucidate the epidemiology of C. difficile and C. perfringens in dogs and to better our understanding of C. difficile as a zoonotic agent. This is the first study to report the binary toxin gene in C. difficile strains isolated from dogs in Brazil.

Silva, Rodrigo Otavio Silveira; Santos, Renata Lara Resende; Pires, Prhiscylla Sadana; Pereira, Luiz Carlos; Pereira, Silvia Trindade; Duarte, Marina Carvalho; de Assis, Ronnie Antunes; Lobato, Francisco Carlos Faria

2013-01-01

216

Mode of binding of RNA polymerase ? subunit to the phased A-tracts upstream of the phospholipase C gene promoter of Clostridium perfringens.  

PubMed

Three phased A5-6-tracts lie upstream of the promoter of plc encoding the ?-toxin (phospholipase C) of Clostridium perfringens. The ? subunits of C. perfringens RNA polymerase bind directly to the phased A-tracts via the C-terminal domain of the ? subunit (?CTD). To identify the amino acid residues involved in the binding of C. perfringens ? subunits to the phased A-tracts, 27 amino acid residues in C. perfringens ?CTD were substituted with alanine. The affinities of the mutated ? subunits for the phased A-tracts were examined by gel shift assays and surface plasmon resonance (SPR). The SPR analyses revealed that the phased A-tracts themselves facilitated a complex formation between the phased A-tracts and C. perfringens ? subunits [Kd was 6.1 (±0.3) × 10(-8) M], and that Arg261, Asn264, Gly292 and Lys294 in C. perfringens ?CTD were critical for the binding to the phased A-tracts. The topology of these amino acid residues on the predicted structure of C. perfringens ?CTD indicated a contact path with the phased A-tracts that was similar to that of Escherichia coli ?CTD with the upstream (UP) element. On the other hand, SPR analyses at different temperatures (15, 25 and 37 °C) indicated that the affinity of the C. perfringens ? subunits for the phased A-tracts increased in a low-temperature-dependent manner, whereas that of the E. coli ? subunit for the UP element did not. This suggests that the phased A-tracts may not simply be a subset of the UP element, and that they show specific binding activity with the RNA polymerase ? subunit. PMID:23810806

Katayama, Seiichi; Ishibashi, Kotaro; Gotoh, Kazuyoshi; Nakamura, Daisuke

2013-06-27

217

Efficient generation of a reshaped human mAb specific for the alpha toxin of Clostridium perfringens.  

PubMed

We have used the technique of antibody reshaping to produce a humanized antibody specific for the alpha toxin of Clostridium perfringens. The starting antibody was from a mouse hybridoma from which variable (V) region nucleotide sequences were determined. The complementarity-determining regions (CDRs) from these V regions were then inserted into human heavy and light chain V region genes with human constant region gene fragments subsequently added. The insertion of CDRs alone into human frameworks did not produce a functional reshaped antibody and modifications to the V region framework were required. With minor framework modifications, the affinity of the original murine mAb was restored and even exceeded. Where affinity was increased, an altered binding profile to overlapping peptides was observed. Computer modelling of the reshaped heavy chain V regions suggested that amino acids adjacent to CDRs can either contribute to, or distort, CDR loop conformation and must be adjusted to achieve high binding affinity. PMID:7716162

Tempest, P R; White, P; Williamson, E D; Titball, R W; Kelly, D C; Kemp, G J; Gray, P M; Forster, S J; Carr, F J; Harris, W J

1994-12-01

218

Influence of pH, nutrient availability, and growth rate on amine production by Bacteroides fragilis and Clostridium perfringens.  

PubMed Central

Dimethylamine, methylamine, propylamine, and pyrrolidine were the major amines formed by Bacteroides fragilis NCDO 2217 during the active phase of growth in batch culture. Production of these metabolites was strongly pH dependent and was optimal under acidic conditions (pH 6.0). Low pH also favored the formation of pyrrolidine, cadaverine, and dimethylamine by Clostridium perfringens C523, but the reverse was the case with putrescine, butylamine, and propylamine, where production was maximal at neutral pH. B. fragilis was grown in continuous culture under either starch or casein limitation. Amine formation was influenced by carbohydrate availability and was greatest when the bacteria were grown at high growth rates (dilution rate, 0.20/h) under starch limitation, where they constituted about 18% of the total fermentation products measured. Amine production was optimal and increased concomitantly with growth rate when C. perfringens was grown in glucose-limited continuous culture. Under conditions of high growth rate and glucose limitation, amines accounted for approximately 27% of the fermentation products measured. When glucose in the feed medium was increased from 5 to 15 g/liter, amine production was repressed, and under these nutritional conditions the growth rate had little effect on the process.

Allison, C; Macfarlane, G T

1989-01-01

219

Germination of Heat- and Alkali-Altered Spores of Clostridium perfringens Type A by Lysozyme and an Initiation Protein  

PubMed Central

The normal system functioning in the utilization of metabolizable germinants by both heat-sensitive and heat-resistant spores of Clostridium perfringens was inactivated by heat or by treatment of the spores with alkali to remove a soluble coat protein layer. Altered spores were incapable of germination (less than 1%) and outgrowth (less than 0.0005%) in complex media without the addition of either lysozyme or an initiation protein produced by C. perfringens. The addition of either of these agents permitted, in the case of alkali-treated spores, both 90 to 95% germination and outgrowth, as measured by colony formation. In the case of heat-damaged spores, only 50% germination and 2% outgrowth resulted from addition of the initiation protein, whereas lysozyme permitted 85% germination and 8% outgrowth. Alteration of the spores by heat or alkali apparently inactivated the normal lytic system responsible for cortical degradation during germination. Kinetics of production of the initiation protein and conditions affecting both its activity and that of lysozyme on altered spores are described.

Duncan, Charles L.; Labbe, Ronald G.; Reich, Robert R.

1972-01-01

220

Clostridium perfringens Epsilon-Toxin Increases Permeability of Single Perfused Microvessels of Rat Mesentery  

Microsoft Academic Search

toxin. We found that microvessels were highly sensitive to toxin. At 10 gm l1 the Lp increased irreversibly to more than 15 times the control value by 10 min. At 0.3 gm l1 no increase in Lp was observed for up to 90 min. The toxin-induced increase in Lp was consistent with changes in ultrastructure of microvessels exposed to the

R. H. Adamson; J. C. Ly; M. Fernandez-Miyakawa; S. Ochi; J. Sakurai; F. Uzal; F. E. Curry

2005-01-01

221

Genomic Analysis of Clostridium perfringens Bacteriophage ?3626, Which Integrates into guaA and Possibly Affects Sporulation  

PubMed Central

Two temperate viruses, ?3626 and ?8533, have been isolated from lysogenic Clostridium perfringens strains. Phage ?3626 was chosen for detailed analysis and was inspected by electron microscopy, protein profiling, and host range determination. For the first time, the nucleotide sequence of a bacteriophage infecting Clostridium species was determined. The virus belongs to the Siphoviridae family of the tailed phages, the order Caudovirales. Its genome consists of a linear double-stranded DNA molecule of 33,507 nucleotides, with invariable 3?-protruding cohesive ends of nine residues. Fifty open reading frames were identified, which are organized in three major life cycle-specific gene clusters. The genes required for lytic development show an opposite orientation and arrangement compared to the lysogeny control region. A function could be assigned to 19 gene products, based upon bioinformatic analyses, N-terminal amino acid sequencing, or experimental evidence. These include DNA-packaging proteins, structural components, a dual lysis system, a putative lysogeny switch, and proteins that are involved in replication, recombination, and modification of phage DNA. The presence of genes encoding a putative sigma factor related to sporulation-dependent sigma factors and a putative sporulation-dependent transcription regulator suggests a possible interaction of ?3626 with onset of sporulation in C. perfringens. We found that the ?3626 attachment site attP lies in a noncoding region immediately downstream of int. Integration of the viral genome occurs into the bacterial attachment site attB, which is located within the 3? end of a guaA homologue. This essential housekeeping gene is functionally independent of the integration status, due to reconstitution of its terminal codons by phage sequence.

Zimmer, Markus; Scherer, Siegfried; Loessner, Martin J.

2002-01-01

222

Ent?rite n?crotique chez le poulet de gril II. Caract?res des souches de Clostridium perfringens isol?es  

PubMed Central

A Gram positive bacillus, strictly anaerobic, was isolated from the viscera of all diseased birds showing lesions of necrotic enteritis. Its morphology and biochemical reactions, the presence of alpha and thêta hemolysins and the production of a lecithinase-C in vitro, all these characteristics indicated a similarity to those belonging to the group of Clostridium perfringens. The two hemolysins were neutralized in vitro only by the antitoxin A. Broiler chickens injected I.V. with a Viande-Foie (VF) broth culture of Clostridium perfringens together with the antitoxin A survived, whereas those receiving antitoxin C died. These results seem to indicate that this organism belongs to the type A. This bacillus was sensitive to a great variety of antibiotics, except neomycin.

Bernier, G.; Filion, R.; Malo, R.; Phaneuf, J.-B.

1974-01-01

223

Disruption of the gene ( spo0A) encoding sporulation transcription factor blocks endospore formation and enterotoxin production in enterotoxigenic Clostridium perfringens type A  

Microsoft Academic Search

This study identified a functional spo0A ORF in enterotoxigenic Clostridium perfringens type A. To evaluate the function of spo0A, an isogenic spo0A knock-out mutant was constructed. The spo0A mutant was unable to form endospores and produce enterotoxin, however, these defects could be restored by complementing the mutant with a recombinant plasmid carrying the wild-type spo0A gene. These results provide evidence

I-Hsiu Huang; Michael Waters; Roberto R Grau; Mahfuzur R Sarker

2004-01-01

224

The Spatial Organization of the VirR Boxes Is Critical for VirR-Mediated Expression of the Perfringolysin O Gene, pfoA, from Clostridium perfringens  

Microsoft Academic Search

The transcriptional regulation of toxin production in the gram-positive anaerobe Clostridium perfringens involves a two-component signal transduction system that comprises the VirS sensor histidine kinase and its cognate response regulator, VirR. Previous studies showed that VirR binds independently to a pair of imperfect direct repeats, now designated VirR box 1 and VirR box 2, located immediately upstream of the promoter

Jackie K. Cheung; Bruno Dupuy; Deanna S. Deveson; Julian I. Rood

2004-01-01

225

The VirR Response Regulator from Clostridium perfringens Binds Independently to Two Imperfect Direct Repeats Located Upstream of the pfoA Promoter  

Microsoft Academic Search

Regulation of toxin production in the gram-positive anaerobe Clostridium perfringens occurs at the level of transcription and involves a two-component signal transduction system. The sensor histidine kinase is encoded by the virS gene, while its cognate response regulator is encoded by the virR gene. We have constructed a VirR expression plasmid in Escherichia coli and purified the resultant His-tagged VirR

JACKIE K. CHEUNG; JULIAN I. ROOD

2000-01-01

226

Immunization with the C?Domain of ??Toxin Prevents Lethal Infection, Localizes Tissue Injury, and Promotes Host Response to Challenge with Clostridium perfringens  

Microsoft Academic Search

Clostridium perfringens gas gangrene is characterized by rapid tissue destruction, impaired host response, and, often, death. Phospholipase C (a-toxin) is the virulence factor most responsible for these pathologies. The present study investigated the efficacy of active immunization with the C-terminal domain of a-toxin (Cpa247- 370) in a murine model of gas gangrene. Primary end points of the study were survival,

Marie Jepson

2004-01-01

227

PREDICTIVE MODEL FOR GROWTH OF CLOSTRIDIUM PERFRINGENS DURING COOLING OF COOKED UNCURED BEEF  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper considers two models that have been used for modeling growth of C. perfringens during cooling. Using a common approach or methodology for constructing models, there was no appreciable difference between the model predictions when the population of cells was within the lag or exponential ...

228

Phospholipase C produced by Clostridium botulinum types C and D: comparison of gene, enzymatic, and biological activities with those of Clostridium perfringens alpha-toxin.  

PubMed

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. PMID:23439504

Fatmawati, Ni Nengah Dwi; Sakaguchi, Yoshihiko; Suzuki, Tomonori; Oda, Masataka; Shimizu, Kenta; Yamamoto, Yumiko; Sakurai, Jun; Matsushita, Osamu; Oguma, Keiji

2013-01-01

229

The relationship between the presence of Helicobacter pylori, Clostridium perfringens type A, Campylobacter spp, or fungi and fatal abomasal ulcers in unweaned beef calves.  

PubMed Central

A case-control study involving 30 unweaned beef calves was conducted to determine whether specific species of bacteria or fungi were associated with fatal abomasal ulcer formation. Special microbiological and histological techniques were used to detect Clostridium perfringens type A, Helicobacter pylori, or Campylobacter spp. It has been speculated that these bacteria are potential ulcerogenic agents of unweaned beef calves. Calves were recruited for the study at necropsy, with those dying of either a perforating or a hemorrhagic ulcer representing the cases, and calves of a similar age dying of a disease unrelated to the abomasum representing the controls. Helicobacter pylori was not visualized in or cultured from any of the abomasal tissue samples. Clostridium perfringens type A was isolated from 78.6% of the cases and 75% of the controls. These isolates were further dichotomized into "heavy" and "light" growth; no significant association was found between ulcers and the amount of growth. A light growth of Campylobacter spp. was recovered from 3 cases and 3 controls. There was no compelling evidence to suggest that Clostridium perfringens type A, Helicobacter pylori, or Campylobacter spp. were involved in ulcer formation.

Jelinski, M D; Ribble, C S; Chirino-Trejo, M; Clark, E G; Janzen, E D

1995-01-01

230

Dissecting the Contributions of Clostridium perfringens Type C Toxins to Lethality in the Mouse Intravenous Injection Model  

PubMed Central

The gram-positive anaerobe Clostridium perfringens produces a large arsenal of toxins that are responsible for histotoxic and enteric infections, including enterotoxemias, in humans and domestic animals. C. perfringens type C isolates, which cause rapidly fatal diseases in domestic animals and enteritis necroticans in humans, contain the genes for alpha toxin (plc), perfringolysin O (pfoA), beta toxin (cpb), and sometimes beta2 toxin (cpb2) and/or enterotoxin (cpe). Due to the economic impact of type C-induced diseases, domestic animals are commonly vaccinated with crude type C toxoid (prepared from inactivated culture supernatants) or bacterin/toxoid vaccines, and it is not clear which toxin(s) present in these vaccines actually elicits the protective immune response. To improve type C vaccines, it would be helpful to assess the contribution of each toxin present in type C supernatants to lethality. To address this issue, we surveyed a large collection of type C isolates to determine their toxin-producing abilities. When late-log-phase vegetative culture supernatants were analyzed by quantitative Western blotting or activity assays, most type C isolates produced at least three lethal toxins, alpha toxin, beta toxin, and perfringolysin O, and several isolates also produced beta2 toxin. In the mouse intravenous injection model, beta toxin was identified as the main lethal factor present in type C late-log-phase culture supernatants. This conclusion was based on monoclonal antibody neutralization studies and regression analyses in which the levels of alpha toxin, beta toxin, perfringolysin O, and beta2 toxin production were compared with lethality. Collectively, our results highlight the importance of beta toxin for type C-induced toxemia.

Fisher, Derek J.; Fernandez-Miyakawa, Mariano E.; Sayeed, Sameera; Poon, Rachael; Adams, Victoria; Rood, Julian I.; Uzal, Francisco A.; McClane, Bruce A.

2006-01-01

231

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

PubMed

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. PMID:23027533

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

2012-10-01

232

Freezing or adding trypsin inhibitor to equine intestinal contents extends the lifespan of Clostridium perfringens beta toxin for diagnostic purposes.  

PubMed

Clostridium perfringens type C causes necrotizing enteritis mostly in neonatal animals of several species, including horses. The virulence of C. perfringens type C is mostly mediated by beta toxin (CPB). This toxin is highly sensitive to the action of trypsin and other proteases, which explains the increased susceptibility of neonatal animals to type C infections. Final confirmation of type C disease diagnosis should be based on detection of CPB in the intestinal content of affected animals. However, because CPB is so sensitive to the action of proteases, it is believed that this toxin persists for only a limited period of time in specimens of intestinal content of animals collected for diagnostic purposes. This study was therefore performed to determine the stability of CPB in intestinal content of horses stored at different temperatures and to evaluate the use of trypsin inhibitor to extend the lifespan of CPB in intestinal content of horses. When the intestinal content of horses that had been spiked with different amounts of CPB was tested by a capture ELISA technique to detect CPB, 319 LD(50) of CPB per milliliter was the lowest amount that could be detected. When equine intestinal content spiked with 319 LD(50)/ml was stored at 4 °C, CPB was detected by ELISA until day 8 after spiking. Samples spiked with the same amount of CPB and stored at -20 °C were positive for at least 5 weeks after spiking. When intestinal samples spiked with 319 LD(50)/ml of CPB were mixed with 0.1 mg/ml or 1.0 mg/ml of trypsin inhibitor and stored at 4 °C, all the samples were positive for at least 5 weeks after spiking. This study demonstrates that C. perfringens CPB present in equine intestinal samples stored at 4 °C cannot be detected by ELISA for more than 8 days. Freezing the samples at -20 °C or adding trypsin inhibitor before storage at 4 °C preserves the lifespan of CPB for at least 5 weeks. PMID:22516562

Macias Rioseco, Melissa; Beingesser, Juliann; Uzal, Francisco A

2012-04-12

233

Human Claudin-8 and -14 Are Receptors Capable of Conveying the Cytotoxic Effects of Clostridium perfringens Enterotoxin  

PubMed Central

ABSTRACT Clostridium perfringens enterotoxin (CPE) contributes to several important human gastrointestinal (GI) diseases. This toxin and its derivatives are also being explored for translational applications, i.e., cancer therapy or drug delivery. Some, but not all, members of the 24-member claudin (Cldn) family of mammalian tight junction proteins can serve as CPE receptors. Among the human Cldns (hCldns), hCldn-3 and -4 are known to convey CPE sensitivity when expressed by fibroblast transfectants. However, other Cldns are also reportedly expressed in the intestines, where they might contribute to natural CPE-mediated GI disease, and in other organs, where they might react with CPE-based therapeutics. Therefore, the current study assessed whether two additional hCldns beside hCldn-3 and -4 are also functional CPE receptors. Using Cldn-expressing transfectants, hCldn-8 and -14 were shown to convey CPE-mediated cytotoxicity at pathophysiologically relevant concentrations of this toxin, although ~2-to-10-fold less efficiently than hCldn-4. Site-directed mutagenesis then demonstrated that the N146 residue in hCldn-14 and the S151 residue in hCldn-8 are largely responsible for modulating the weaker CPE binding properties of hCldn-8 and -14 versus hCldn-4, which broadens understanding of Cldn:CPE binding interactions. Since Cldn-8 and -14 are reportedly expressed in mammalian intestines, the current results support the possibility that these two hCldns contribute to natural CPE-mediated gastrointestinal disease and could be CPE-based therapeutic targets for cancers overexpressing those claudins. However, these results also suggest caution during therapeutic use of CPE, which might trigger toxic side effects in normal human tissues producing hCldn-8 or -14, as well as in those producing hCldn-3 or -4. IMPORTANCE Clostridium perfringens enterotoxin (CPE) is responsible for the gastrointestinal symptoms of the second-most-common bacterial food-borne illness and is also being explored for use as a cancer therapeutic or for increasing drug delivery. Until now, the only known human CPE receptors were claudin-3 and -4. This work shows that human claudin-8 and -14 can also bind CPE and convey cytotoxicity, although slightly less efficiently than claudin-3 and -4. The claudin-8 and -14 residues responsible for this weaker CPE binding were identified, shedding new light on CPE:claudin interactions.

Shrestha, Archana; McClane, Bruce A.

2013-01-01

234

Clostridium perfringens Delta Toxin Is Sequence Related to Beta Toxin, NetB, and Staphylococcus Pore-Forming Toxins, but Shows Functional Differences  

PubMed Central

Clostridium perfringens produces numerous toxins, which are responsible for severe diseases in man and animals. Delta toxin is one of the three hemolysins released by a number of C. perfringens type C and possibly type B strains. Delta toxin was characterized to be cytotoxic for cells expressing the ganglioside GM2 in their membrane. Here we report the genetic characterization of Delta toxin and its pore forming activity in lipid bilayers. Delta toxin consists of 318 amino acids, its 28 N-terminal amino acids corresponding to a signal peptide. The secreted Delta toxin (290 amino acids; 32619 Da) is a basic protein (pI 9.1) which shows a significant homology with C. perfringens Beta toxin (43% identity), with C. perfringens NetB (40% identity) and, to a lesser extent, with Staphylococcus aureus alpha toxin and leukotoxins. Recombinant Delta toxin showed a preference for binding to GM2, in contrast to Beta toxin, which did not bind to gangliosides. It is hemolytic for sheep red blood cells and cytotoxic for HeLa cells. In artificial diphytanoyl phosphatidylcholine membranes, Delta and Beta toxin formed channels. Conductance of the channels formed by Delta toxin, with a value of about 100 pS to more than 1 nS in 1 M KCl and a membrane potential of 20 mV, was higher than those formed by Beta toxin and their distribution was broader. The results of zero-current membrane potential measurements and single channel experiments suggest that Delta toxin forms slightly anion-selective channels, whereas the Beta toxin channels showed a preference for cations under the same conditions. C. perfringens Delta toxin shows a significant sequence homolgy with C. perfringens Beta and NetB toxins, as well as with S. aureus alpha hemolysin and leukotoxins, but exhibits different channel properties in lipid bilayers. In contrast to Beta toxin, Delta toxin recognizes GM2 as receptor and forms anion-selective channels.

Manich, Maria; Knapp, Oliver; Gibert, Maryse; Maier, Elke; Jolivet-Reynaud, Colette; Geny, Blandine; Benz, Roland; Popoff, Michel R.

2008-01-01

235

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

PubMed

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 identify putative prophage lysins or autolysins by BLAST analyses encoded by the genomes of C. perfringens isolates. A predicted N-acetylmuramoyl-L-alanine amidase or MurNAc-LAA (also known as peptidoglycan aminohydrolase, NAMLA amidase, NAMLAA, amidase 3, and peptidoglycan amidase; EC 3.5.1.28) was identified that would hydrolyze the amide bond between N-acetylmuramoyl and L-amino acids in certain cell wall glycopeptides. The gene encoding this protein was subsequently cloned from genomic DNA of a C. perfringens isolate by polymerase chain reaction, and the gene product (PlyCpAmi) was expressed to determine if it could be utilized as an antimicrobial to control the bacterium. By spot assay, lytic zones were observed for the purified amidase and the E. coli expression host cellular lysate containing the amidase gene. Turbidity reduction and plate counts of C. perfringens cultures were significantly reduced by the expressed protein and observed morphologies for cells treated with the amidase appeared vacuolated, non-intact, and injured compared to the untreated cells. Among a variety of C. perfringens strains, there was little gene sequence heterogeneity that varied from 1 to 21 nucleotide differences. The results further demonstrate that it is possible to discover lytic proteins encoded in the genomes of bacteria that could be utilized to control bacterial pathogens. PMID:23934074

Tillman, Glenn E; Simmons, Mustafa; Garrish, Johnna K; Seal, Bruce S

2013-08-11

236

Membrane Translocation of Binary Actin-ADP-Ribosylating Toxins from Clostridium difficile and Clostridium perfringens Is Facilitated by Cyclophilin A and Hsp90 ?  

PubMed Central

Some hypervirulent strains of Clostridium difficile produce the binary actin-ADP-ribosylating toxin C. difficile transferase (CDT) in addition to Rho-glucosylating toxins A and B. It has been suggested that the presence of CDT increases the severity of C. difficile-associated diseases, including pseudomembranous colitis. CDT contains a binding and translocation component, CDTb, that mediates the transport of the separate enzyme component CDTa into the cytosol of target cells, where CDTa modifies actin. Here we investigated the mechanism of cellular CDT uptake and found that bafilomycin A1 protects cultured epithelial cells from intoxication with CDT, implying that CDTa is translocated from acidified endosomal vesicles into the cytosol. Consistently, CDTa is translocated across the cytoplasmic membranes into the cytosol when cell-bound CDT is exposed to acidic medium. Radicicol and cyclosporine A, inhibitors of the heat shock protein Hsp90 and cyclophilins, respectively, protected cells from intoxication with CDT but not from intoxication with toxins A and B. Moreover, both inhibitors blocked the pH-dependent membrane translocation of CDTa, strongly suggesting that Hsp90 and cyclophilin are crucial for this process. In contrast, the inhibitors did not interfere with the ADP-ribosyltransferase activity, receptor binding, or endocytosis of the toxin. We obtained comparable results with the closely related iota-toxin from Clostridium perfringens. Moreover, CDTa and Ia, the enzyme component of iota-toxin, specifically bound to immobilized Hsp90 and cyclophilin A in vitro. In combination with our recently obtained data on the C2 toxin from C. botulinum, these results imply a common Hsp90/cyclophilin A-dependent translocation mechanism for the family of binary actin-ADP-ribosylating toxins.

Kaiser, Eva; Kroll, Claudia; Ernst, Katharina; Schwan, Carsten; Popoff, Michel; Fischer, Gunter; Buchner, Johannes; Aktories, Klaus; Barth, Holger

2011-01-01

237

The virR gene, a member of a class of two-component response regulators, regulates the production of perfringolysin O, collagenase, and hemagglutinin in Clostridium perfringens.  

PubMed Central

The perfringolysin O (theta-toxin) gene (pfoA) of Clostridium perfringens was cloned into an Escherichia coli-C. perfringens shuttle vector, and the pfoA gene was expressed in mutants of C. perfringens 13 which lacked the production of perfringolysin O. One group (SI117) could express the pfoA gene, and the other (SI112) could not. A mutation in the regulatory system for pfoA gene expression was suspected in SI112. A chromosomal DNA library constructed from strain 13 was transformed into strain SI112 to identify the regulatory gene(s) for the pfoA gene. Five strains of 10,000 transformants restored perfringolysin O production. All contained a 2.5-kb DNA fragment. This fragment activated the transcription of the pfoA gene and also restored the production of collagenase (kappa-toxin) and hemagglutinin in strain SI112. Deletion analysis showed that a 1.25-kb region was sufficient for the trans activity, and sequence analysis disclosed that open reading frame 2 (ORF2) was located in this region. A homology search for the deduced amino acid sequence revealed that ORF2 was homologous to a response regulator in a two-component signal transduction system. ORF2 was designated virR, and it is suggested that the virR gene plays an important role in the pathogenicity of C. perfringens. Images

Shimizu, T; Ba-Thein, W; Tamaki, M; Hayashi, H

1994-01-01

238

Alterations in DNA Gyrase and Topoisomerase IV in Resistant Mutants of Clostridium perfringens Found after In Vitro Treatment with Fluoroquinolones  

PubMed Central

To compare mutations in the DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) genes of Clostridium perfringens, which are associated with in vitro exposure to fluoroquinolones, resistant mutants were selected from eight strains by serial passage in the presence of increasing concentrations of norfloxacin, ciprofloxacin, gatifloxacin, or trovafloxacin. The nucleotide sequences of the entire gyrA, gyrB, parC, and parE genes of 42 mutants were determined. DNA gyrase was the primary target for each fluoroquinolone, and topoisomerase IV was the secondary target. Most mutations appeared in the quinolone resistance-determining regions of gyrA (resulting in changes of Asp-87 to Tyr or Gly-81 to Cys) and parC (resulting in changes of Asp-93 or Asp-88 to Tyr or Ser-89 to Ile); only two mutations were found in gyrB, and only two mutations were found in parE. More mutants with multiple gyrA and parC mutations were produced with gatifloxacin than with the other fluoroquinolones tested. Allelic diversity was observed among the resistant mutants, for which the drug MICs increased 2- to 256-fold. Both the structures of the drugs and their concentrations influenced the selection of mutants.

Rafii, Fatemeh; Park, Miseon; Novak, John S.

2005-01-01

239

Antagonism exerted by an association of a Bacteroides thetaiotaomicron strain and a Fusobacterium necrogenes strain against Clostridium perfringens in gnotobiotic mice and in fecal suspensions incubated in vitro.  

PubMed Central

Antagonism between an association of Bacteroides thetaiotaomicron and Fusobacterium necrogenes strains and two strains of Clostridium perfringens was evidenced both in vivo in gnotobiotic mice and ex vivo in fecal suspensions incubated for 22 h at 37 degrees C. Several features of this antagonism were similar in and ex vivo. (i) An obligate and continuous synergy between B. thetaiotaomicron and F. necrogenes was required; (ii) the two C. perfringens strains did not respond to the same extent to this antagonism; and (iii) expression of the antagonism was host and diet dependent. Neither diffusible nor soluble inhibitory substances were detectable in feces of gnotobiotic mice, nor could depletion of nutrients be identified as causing antagonism in both in and ex vivo experiments. Our findings support the hypothesis that a reversible bacteriostasis induced by the inhibitory strains acting together continuously, and hindering the target strain from utilizing available nutrients, was responsible for this antagonism.

Yurdusev, N; Ladire, M; Ducluzeau, R; Raibaud, P

1989-01-01

240

The Interaction of a Carbohydrate-Binding Module from a Clostridium perfringens N-Acetyl-beta-hexosaminidase with its Carbohydrate Receptor  

SciTech Connect

Clostridium perfringens is a notable colonizer of the human gastrointestinal tract. This bacterium is quite remarkable for a human pathogen by the number of glycoside hydrolases found in its genome. The modularity of these enzymes is striking as is the frequent occurrence of modules having amino acid sequence identity with family 32 carbohydrate-binding modules (CBMs), often referred to as F5/8 domains. Here we report the properties of family 32 CBMs from a C. perfringens N-acetyl-{beta}-hexosaminidase. Macroarray, UV difference, and isothermal titration calorimetry binding studies indicate a preference for the disaccharide LacNAc ({beta}-d-galactosyl-1,4-{beta}-d-N-acetylglucosamine). The molecular details of the interaction of this CBM with galactose, LacNAc, and the type II blood group H-trisaccharide are revealed by x-ray crystallographic studies at resolutions of 1.49, 2.4, and 2.3 Angstroms, respectively.

Ficko-Blean,E.; Boraston, A.

2006-01-01

241

Typing of sheep clinical isolates and identification of enterotoxigenic Clostridium perfringens strains by classical methods and by polymerase chain reaction (PCR) 1 1 Work is currently under way (involving the French Central Veterinary Research Laboratory and the Institut Pasteur in Paris) to validate a diagnostic kit for the typing of C. perfringens and for detection of the enterotoxin. Specific primers have been chosen based on the published genome sequences for ?-toxin [1–3], ?-toxin [4], ?-toxin [5] and enterotoxin [6  

Microsoft Academic Search

A simple procedure was developed to identify toxitypes of Clostridium perfringens of different origins. Ninety strains of C. perfringens were identified by classical bacteriological methods, typing of the strains was done by a seroneutralisation test on mice. Production of enterotoxin was tested and all strains were analysed by PCR using gene of toxin ?, gene of toxin ?, gene of

B Kadra; J. P Guillou; M Popoff; P Bourlioux

1999-01-01

242

Use of organic acids for the control of Clostridium perfringens in cooked vacuum-packaged restructured roast beef during an alternative cooling procedure.  

PubMed

This study was conducted to determine how well Clostridium perfringens spores germinate and grow in restructured roast beef treated with different commercial organic salts during an alternative chilling procedure. The meat was prepared according to an industrial recipe (10% water, 1.5% sodium chloride, and 0.5% sodium triphosphate). The base meat was treated with sodium citrate at 2 or 4.8% (wt/wt), buffered to a pH of 5.6, 5.0, or 4.4 (six treatments); a 60% (wt/wt) solution of sodium lactate at 2 or 4.8% (wt/wt); sodium acetate at 0.25% (wt/wt); or sodium diacetate at 0.25% (wt/wt). Untreated meat was used as a control. Meat samples were inoculated with a three-strain cocktail of C. perfringens spores (strains ATCC 10388, NCTC 8238, and NCTC 8239). Meat was vacuum packaged in bags and cooked in a stirred water bath to an internal temperature of 75 degrees C for 20 min, and then the bags were cooled from 54.4 to 4.4 degrees C within 18 h. Samples were taken after inoculation, after cooking, and after chilling. Spore and vegetative cell counts were obtained after incubation at 37 degrees C for 8 to 10 h in Fung's Double Tubes containing tryptose sulfite agar without egg yolk enrichment. Cooking was not sufficient to eliminate C. perfringens spores. Over the 18-h cooling period, sodium citrate, sodium lactate, and sodium diacetate reduced the growth of C. perfringens to < 1 log unit, a growth level that meets U.S. Department of Agriculture performance standards. The use of sodium citrate or sodium lactate at a concentration of > or = 2% (wt/wt) inhibited C. perfringens growth over the 18-h cooling period. PMID:12929827

Sabah, J R; Thippareddi, H; Marsden, J L; Fung, D Y C

2003-08-01

243

Characterization of bacteriophages virulent for Clostridium perfringens and identification of phage lytic enzymes as alternatives to antibiotics for potential control of the bacterium.  

PubMed

There has been a resurgent interest in the use of bacteriophages or their gene products to control bacterial pathogens as alternatives to currently used antibiotics. Clostridium perfringens is a gram-positive, spore-forming anaerobic bacterium that plays a significant role in human foodborne disease as well as non-foodborne human, animal, and avian diseases. Countries that have complied with the ban on antimicrobial growth promoters in feeds have reported increased incidences of C. perfringens-associated diseases in poultry. To address these issues, new antimicrobial agents, putative lysins encoded by the genomes of bacteriophages, are being identified in our laboratory. Poultry intestinal material, soil, sewage, and poultry processing drainage water were screened for virulent bacteriophages that could lyse C. perfringens and produce clear plaques in spot assays. Bacteriophages were isolated that had long noncontractile tails, members of the family Siphoviridae, and with short noncontractile tails, members of the family Podoviridae. Several bacteriophage genes were identified that encoded N-acetylmuramoyl-l-alanine amidases, lysozyme-endopeptidases, and a zinc carboxypeptidase domain that has not been previously reported in viral genomes. Putative phage lysin genes (ply) were cloned and expressed in Escherichia coli. The recombinant lysins were amidases capable of lysing both parental phage host strains of C. perfringens as well as other strains of the bacterium in spot and turbidity reduction assays, but did not lyse any clostridia beyond the species. Consequently, bacteriophage gene products could eventually be used to target bacterial pathogens, such as C. perfringens via a species-specific strategy, to control animal and human diseases without having deleterious effects on beneficial probiotic bacteria. PMID:23300321

Seal, Bruce S

2013-02-01

244

Inhibition of Clostridium perfringens spore germination and outgrowth by buffered vinegar and lemon juice concentrate during chilling of ground turkey roast containing minimal ingredients.  

PubMed

Inhibition of Clostridium perfringens spore germination and outgrowth in ground turkey roast containing minimal ingredients (salt and sugar), by buffered vinegar (MOstatin V) and a blend (buffered) of lemon juice concentrate and vinegar (MOstatin LV) was evaluated. Ground turkey roast was formulated to contain sea salt (1.5%), turbinado sugar (0.5%), and various concentrations of MOstatin V (0.75, 1.25, or 2.5%) or MOstatin LV (1.5, 2.5, or 3.5%), along with a control (without MOstatins). The product was inoculated with a three-strain spore cocktail of C. perfringens to obtain initial spore levels of ca. 2.0 to 0.5 log CFU/g. Inoculated products were vacuum packaged, heat shocked for 20 min at 75 degrees C, and cooled exponentially from 54.4 to 4.0 degrees C in 6.5, 9, 12, 15, 18, or 21 h. In control samples without MOstatin V or MOstatin LV, C. perfringens populations reached 2.98, 4.50, 5.78, 7.05, 7.88, and 8.19 log CFU/g (corresponding increases of 0.51, 2.29, 3.51, 4.79, 5.55, and 5.93 log CFU/g) in 6.5, 9, 12, 15, 18, and 21 h of chilling, respectively. MOstatin V (2.5%) and MOstatin LV (3.5%) were effective in inhibiting C. perfringens spore germination and outgrowth in ground turkey roast to <1.0 log CFU/g during abusive chilling of the product within 21 h. Buffered vinegar and a blend (buffered) of lemon juice concentrate and vinegar were effective in controlling germination and outgrowth of C. perfringens spores in turkey roast containing minimal ingredients. PMID:20202331

Valenzuela-Martinez, Carol; Pena-Ramos, Aida; Juneja, Vijay K; Korasapati, Nageswara Rao; Burson, Dennis E; Thippareddi, Harshavardhan

2010-03-01

245

Predictive model for Clostridium perfringens growth in roast beef during cooling and inhibition of spore germination and outgrowth by organic acid salts.  

PubMed

Spores of foodborne pathogens can survive traditional thermal processing schedules used in the manufacturing of processed meat products. Heat-activated spores can germinate and grow to hazardous levels when these products are improperly chilled. Germination and outgrowth of Clostridium perfringens spores in roast beef during chilling was studied following simulated cooling schedules normally used in the processed-meat industry. Inhibitory effects of organic acid salts on germination and outgrowth of C. perfringens spores during chilling and the survival of vegetative cells and spores under abusive refrigerated storage was also evaluated. Beef top rounds were formulated to contain a marinade (finished product concentrations: 1% salt, 0.2% potassium tetrapyrophosphate, and 0.2% starch) and then ground and mixed with antimicrobials (sodium lactate and sodium lactate plus 2.5% sodium diacetate and buffered sodium citrate and buffered sodium citrate plus 1.3% sodium diacetate). The ground product was inoculated with a three-strain cocktail of C. perfringens spores (NCTC 8238, NCTC 8239, and ATCC 10388), mixed, vacuum packaged, heat shocked for 20 min at 75 degrees C, and chilled exponentially from 54.5 to 7.2 degrees C in 9, 12, 15, 18, or 21 h. C. perfringens populations (total and spore) were enumerated after heat shock, during chilling, and during storage for up to 60 days at 10 degrees C using tryptose-sulfite-cycloserine agar. C. perfringens spores were able to germinate and grow in roast beef (control, without any antimicrobials) from an initial population of ca. 3.1 log CFU/g by 2.00, 3.44, 4.04, 4.86, and 5.72 log CFU/g after 9, 12, 15, 18, and 21 h of exponential chilling. A predictive model was developed to describe sigmoidal C. perfringens growth curves during cooling of roast beef from 54.5 to 7.2 degrees C within 9, 12, 15, 18, and 21 h. Addition of antimicrobials prevented germination and outgrowth of C. perfringens regardless of the chill times. C. perfringens spores could be recovered from samples containing organic acid salts that were stored up to 60 days at 10 degrees C. Extension of chilling time to > or =9 h resulted in >1 log CFU/g growth of C. perfringens under anaerobic conditions in roast beef. Organic acid salts inhibited outgrowth of C. perfringens spores during chilling of roast beef when extended chill rates were followed. Although C. perfringens spore germination is inhibited by the antimicrobials, this inhibition may represent a hazard when such products are incorporated into new products, such as soups and chili, that do not contain these antimicrobials, thus allowing spore germination and outgrowth under conditions of temperature abuse. PMID:16355831

Sánchez-Plata, Marcos X; Amézquita, Alejandro; Blankenship, Erin; Burson, Dennis E; Juneja, Vijay; Thippareddi, Harshavardhan

2005-12-01

246

Comparative genomics of four closely related Clostridium perfringens bacteriophages reveals variable evolution among core genes with therapeutic potential  

PubMed Central

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.

2011-01-01

247

Evidence for coupling of Clostridium perfringens alpha-toxin-induced hemolysis to stimulated phosphatidic acid formation in rabbit erythrocytes.  

PubMed Central

When rabbit erythrocytes were exposed to low concentrations of Clostridium perfringens alpha-toxin, hot-cold hemolysis was observed. The toxin induced production of phosphatidic acid (PA) in a dose-dependent manner when incubated with erythrocytes at 37 degrees C. When erythrocyte membranes were incubated with the toxin and [gamma-32P]ATP in the presence or absence of ethanol, [32P]PA formation was maximal within 30 s, then sharply decreased, and began again after 5 min of incubation. Ethanol had no effect on the early appearance (at approximately 5 min) of PA formation induced by the toxin but significantly inhibited formation of PA over 10 min of incubation. Treatment of erythrocyte membranes with alpha-toxin resulted in the biphasic formation of 1,2-diacylglycerol and PA as well as an increase of inositol-1,4,5-trisphosphate (IP3) and decrease of phosphatidylinositol-4,5-bisphosphate (PIP2) within 30 s. Neomycin inhibited the toxin-induced increase in turbidity of egg yolk suspensions but did not inhibit the toxin-induced hemolysis of intact erythrocytes. On the other hand, neomycin inhibited the toxin-induced hemolysis of saponin-treated erythrocytes. In addition, neomycin inhibited PA formation induced by the toxin in erythrocyte membranes. IP3 was released by incubation of PIP2 with erythrocyte membranes but not by incubation of PIP2 with the toxin. The toxin stimulated the membrane-induced release of IP3 from PIP2. These data suggest that the toxin-induced hemolysis is dependent on the action of phospholipase C in erythrocyte membranes.

Sakurai, J; Ochi, S; Tanaka, H

1993-01-01

248

Preliminary evidence that Clostridium perfringens type A enterotoxin is present in a 160,000-Mr complex in mammalian membranes.  

PubMed Central

Clostridium perfringens type A 125I-enterotoxin (125I-CPE) was bound to rabbit intestinal brush border membranes (BBMs) or Vero cells and then solubilized with 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS). Solubilized radioactivity was analyzed by gel filtration chromatography on a Sepharose 4B column or by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without sample boiling and autoradiography. Specifically bound 125I-CPE extracted from either BBMs or Vero cells was primarily associated with a complex of approximately 160,000 Mr. The CPE complex was partially purified by gel filtration or SDS-PAGE without sample boiling. SDS-PAGE analysis with sample boiling of the partially purified 125I-CPE complex from Vero cells or BBMs suggested that CPE complex contains both a 50,000-Mr protein and a 70,000-Mr protein in approximately equimolar amounts. This result is supported by affinity chromatography with CPE immobilized on Sepharose 4B, which showed the specific interaction of similar size proteins with CPE. The simplest explanation for these results is that CPE (Mr 35,000) interacts with 50,000-Mr and 70,000-Mr eucaryotic proteins to form a membrane-dependent complex of approximately 160,000 Mr. These results suggest that the receptor or target site(s) or both for CPE are similar in both BBMs and Vero cells. The significance of these findings in terms of CPE binding, insertion, and biologic action is discussed. Images

Wnek, A P; McClane, B A

1989-01-01

249

lesion development in a new intestinal loop model indicates the involvement of a shared Clostridium perfringens virulence factor in haemorrhagic enteritis in calves.  

PubMed

Clostridium perfringens-associated enterotoxaemia is a fatal disease in fast growing suckler and veal calves. An intestinal loop model was developed to study the pathogenesis of the disease. Loops were injected with stationary and logarithmic C. perfringens cultures with or without, a milk protein-based commercial milk replacer for calves. Isolates tested were from cases of bovine enterotoxaemia and from calves without signs of enterotoxaemia, in addition to netB-positive and -negative isolates from poultry, a type C isolate from piglets and the human isolate JIR325. All isolates induced necrohaemorrhagic lesions in combination with milk replacer, while all control loops (i.e. medium plus milk replacer) remained histologically normal. In addition, time-course experiments were conducted using an isolate from an outbreak of bovine enterotoxaemia. Histological examination showed that the earliest lesion was congestion of the capillaries, starting within 30 min of inoculation. Haemorrhage and mucosal necrosis began at the tips of the villi 3-4 h after bacterial inoculation. These lesions are similar to those observed in natural cases of bovine enterotoxaemia. Therefore, in this model, necrohaemorrhagic lesions can be induced by C. perfringens isolates from diverse origins, suggesting that the lesions may be caused by one or more virulence factors that are shared by these isolates. PMID:23351504

Valgaeren, B; Pardon, B; Goossens, E; Verherstraeten, S; Schauvliege, S; Timbermont, L; Ducatelle, R; Deprez, P; Van Immerseel, F

2013-01-22

250

The protective e¡ect of breast feeding in relation to sudden infant death syndrome (SIDS): II. The e¡ect of human milk and infant formula preparations on binding of Clostridium perfringens to epithelial cells  

Microsoft Academic Search

Breast feeding is known to protect an infant against gastrointestinal pathogens and epidemiological studies indicate that compared to breast fed infants, formula fed infants are at a greater risk of dying from sudden infant death syndrome (SIDS). Many SIDS infants have symptoms of gastrointestinal infections prior to death and one gastrointestinal pathogen associated with SIDS is Clostridium perfringens. Studies have

Ann E. Gordon; Abdulrahman T. Saadi; Doris A. C. MacKenzie; Valerie S. James; Robert A. Elton; Donald M. Weir; Anthony Busuttil; C. Caroline Blackwell

251

The protective effect of breast feeding in relation to sudden infant death syndrome (SIDS): II. The effect of human milk and infant formula preparations on binding of Clostridium perfringens to epithelial cells  

Microsoft Academic Search

Breast feeding is known to protect an infant against gastrointestinal pathogens and epidemiological studies indicate that compared to breast fed infants, formula fed infants are at a greater risk of dying from sudden infant death syndrome (SIDS). Many SIDS infants have symptoms of gastrointestinal infections prior to death and one gastrointestinal pathogen associated with SIDS is Clostridium perfringens. Studies have

Ann E. Gordon; Abdulrahman T. Saadi; Doris A. C. MacKenzie; Valerie S. James; Robert A. Elton; Donald M. Weir; Anthony Busuttil; C. Caroline Blackwell

1999-01-01

252

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 ?-toxin-encoding gene ( plc)  

Microsoft Academic Search

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 investigate the influence of a commercial essential oil blend, CRINA® Poultry, on the intestinal

L. Abildgaard; O. Hojberg; A. Schramm; K. M. Balle; R. M. Engberg

2010-01-01

253

Use of Genetically Manipulated Strains of Clostridium perfringens Reveals that Both Alpha-Toxin and Theta-Toxin Are Required for Vascular Leukostasis To Occur in Experimental Gas Gangrene  

Microsoft Academic Search

A hallmark of gas gangrene (clostridial myonecrosis) pathology is a paucity of leukocytes infiltrating the necrotic tissue. The cause of this paucity most likely relates to the observation of leukocyte aggregates at the border of the area of tissue necrosis, often within the microvasculature itself. Infecting mice with genetically manipulated strains of Clostridium perfringens type A (deficient in either alpha-toxin

DARREN M. ELLEMOR; REBECCA N. BAIRD; MILENA M. AWAD; RICHARD L. BOYD; JULIAN I. ROOD; JOHN J. EMMINS

1999-01-01

254

[An in vitro alternative to the mouse neutralisation assay for potency testing of betatoxoid containing Clostridium, perfringens type B and type C vaccines for veterinary use  

PubMed

The quality control of Clostridium (C.) perfringens type B and type C vaccines requires animal experiments according to European Pharmacopoiea monograph 363. For potency estimation, the vaccine is first administered to rabbits. In a second step antibodies from these rabbits against C. perfringens betatoxin are measured quantitatively in a mouse neutralisation assay using lethal doses of betatoxin for the challenge. We report about the development of an in vitro assay enabling specific and reproducible measurement of antibodies against C. perfringens betatoxin in rabbit sera. A Capure-Enzyme Linked Immuno Sorbent Assay (ELISA) using a monoclonal antibody against betatoxin as catching antibody was used. A rabbit serumpool freeze dried in 3500 aliquots was always used as reference. This reference serum can be supplied for further national or international collaborative studies. The estimation of relative potency of unknown sera in a parallel line assay was calculated with a computer programme provided by the World health organisation (WHO). The capture-ELISA did not show unspecific reactivity with pre-vaccination sera of cross-reactivity with sera from rabbits immunised with other clostridial antigens e.g. C. perfringens type D, C. chavoei or C. tetani. Reproducibility studies focused on the linear parts of the dose-response curves resulted in intra-assay coefficient of variations of less then 10%. The inter-assay coefficient varied between 12-25% depending on the serum dilutions used. Correlation studies between the result of the animal experiment (only one test) and the capture-ELISA (10 repetitions) from four rabbit serum pools revealed a coefficient of correlation of 0.81-0.84 depending on the basis for calculation of r (Mean or Median from ELISA repetitions). Therefore this test may be a suitable alternative for the currently required mouse neutralisation assay. For acceptance of this test by the European Pharmacopoiea further validation studies are necessary. PMID:11178445

Ebert, Elvira; Kusch, Manuela; Öppling, Volker; Werner, Esther; Cussler, Klaus

1996-01-01

255

The Clostridium perfringens Germinant Receptor Protein GerKC Is Located in the Spore Inner Membrane and Is Crucial for Spore Germination.  

PubMed

The Gram-positive, anaerobic, spore-forming bacterium Clostridium perfringens causes a variety of diseases in both humans and animals, and spore germination is thought to be the first stage of C. perfringens infection. Previous studies have indicated that the germinant receptor (GR) proteins encoded by the bicistronic gerKA-gerKC operon as well as the proteins encoded by the gerKB and gerAA genes are required for normal germination of C. perfringens spores. We now report the individual role of these GR proteins by analyzing the germination of strains carrying mutations in gerKA, gerKC, or both gerKB and gerAA. Western blot analysis was also used to determine the location and numbers of GerKC proteins in spores. Conclusions from this work include the following: (i) gerKC mutant spores germinate extremely poorly with KCl, l-asparagine, a mixture of asparagine and KCl, or NaPi; (ii) gerKC spores germinate significantly more slowly than wild-type and other GR mutant spores with a 1:1 chelate of Ca(2+) and dipicolinic acid and very slightly more slowly with dodecylamine; (iii) the germination defects in gerKC spores are largely restored by expressing the wild-type gerKA-gerKC operon in trans; (iv) GerKC is required for the spores' viability, almost certainly because of the gerKC spores' poor germination; and (v) GerKC is located in the spores' inner membrane, with ?250 molecules/spore. Collectively, these results indicate that GerKC is the main GR protein required for nutrient and nonnutrient germination of spores of C. perfringens food-poisoning isolates. PMID:24013629

Banawas, Saeed; Paredes-Sabja, Daniel; Korza, George; Li, Yunfeng; Hao, Bing; Setlow, Peter; Sarker, Mahfuzur R

2013-09-06

256

A Live Oral Recombinant Salmonella enterica Serovar Typhimurium Vaccine Expressing Clostridium perfringens Antigens Confers Protection against Necrotic Enteritis in Broiler Chickens?  

PubMed Central

Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens, and there is currently no effective vaccine for NE. We previously showed that in broiler chickens protection against NE can be achieved through intramuscular immunization with alpha toxin (AT) and hypothetical protein (HP), and we subsequently identified B-cell epitopes in HP. In the present study, we identified B-cell epitopes in AT recognized by chickens immune to NE. The gene fragments encoding immunodominant epitopes of AT as well as those of HP were codon optimized for Salmonella and cloned into pYA3493, and the resultant plasmid constructs were introduced into an attenuated Salmonella enterica serovar Typhimurium ?9352 vaccine vehicle. The expression of these Clostridium perfringens proteins, alpha toxoid (ATd) and truncated HP (HPt), was confirmed by immunoblotting. The protection of broiler chickens against experimentally induced NE was assessed at both the moderate and the severe levels of challenge. Birds immunized orally with Salmonella expressing ATd were significantly protected against moderate NE, and there was a nonsignificant trend for protection against severe challenge, whereas HPt-immunized birds were significantly protected against both severities of challenge. Immunized birds developed serum IgY and mucosal IgA and IgY antibody responses against Clostridium and Salmonella antigens. In conclusion, this study identified, for the first time, the B-cell epitopes in AT from an NE isolate recognized by chickens and showed the partial protective ability of codon-optimized ATd and HPt against NE in broiler chickens when they were delivered orally by using a Salmonella vaccine vehicle.

Kulkarni, R. R.; Parreira, V. R.; Jiang, Y.-F.; Prescott, J. F.

2010-01-01

257

Use of an Online Survey During an Outbreak of Clostridium perfringens in a Retirement Community-Arizona, 2012.  

PubMed

CONTEXT:: An outbreak of gastrointestinal (GI) illness among retirement community residents was reported to the Maricopa County Department of Public Health. Online surveys can be useful for rapid investigation of disease outbreaks, especially when local health departments lack time and resources to perform telephone interviews. Online survey utility among older populations, which may lack computer access or literacy, has not been defined. OBJECTIVE:: To investigate and implement prevention measures for a GI outbreak and assess the utility of an online survey among retirement community residents. DESIGN:: A retrospective cohort investigation was conducted using an online survey distributed through the retirement community e-mail listserv; a follow-up telephone survey was conducted to assess computer literacy and Internet access. A case was defined as any GI illness occurring among residents during March 1-14, 2012. SETTING:: A barbecue in a retirement community of 3000 residents. PARTICIPANTS:: Retirement community residents. INTERVENTION:: Residents were directed to discard leftover food and seek health care for symptoms. A telephone survey was conducted to assess the utility of online surveys in this population. MAIN OUTCOME MEASURES:: Computer literacy and Internet access of retirement community residents. RESULTS:: Of 1000 residents on the listserv, 370 (37%) completed the online survey (mean age, 69.7 years; 60.6% women); 66 residents (17.8%) reported a GI illness after the barbecue, 63 (95.5%) reported diarrhea, and 5 (7.6%) reported vomiting. Leftover beef from an attendee's refrigerator grew Clostridium perfringens. Of 552 residents contacted by telephone, 113 completed the telephone survey (mean age, 71.3 years; 63.3% women), 101 (89.4%) reported the ability to send e-mail, 82 (81.2%) checked e-mail daily, and 28 (27.7%) checked e-mail on a handheld device. The attack rate was 17.8% for online versus 2.7% for telephone respondents (P < .001). CONCLUSIONS:: This outbreak demonstrated the utility of an online survey to rapidly collect information and implement prevention measures among an older demographic. PMID:23760307

Yasmin, Seema; Pogreba-Brown, Kristen; Stewart, Jennifer; Sunenshine, Rebecca

2013-06-11

258

Incidence of Clostridium perfringens in commercially produced cured raw meat product mixtures and behavior in cooked products during chilling and refrigerated storage.  

PubMed

A total of 445 whole-muscle and ground or emulsified raw pork, beef, and chicken product mixtures acquired from industry sources were monitored over a 10-month period for vegetative and spore forms of Clostridium perfringens. Black colonies that formed on Shahidi-Ferguson perfringens (SFP) agar after 24 h at 37 degrees C were considered presumptive positive. Samples that were positive after a 15-min heat shock at 75 degrees C were considered presumptive positive for spores. Of 194 cured whole-muscle samples, 1.6% were positive; spores were not detected from those samples. Populations of vegetative cells did not exceed 1.70 log10 CFU/g and averaged 1.56 log10 CFU/g. Of 152 cured ground or emulsified samples, 48.7% were positive, and 5.3% were positive for spores. Populations of vegetative cells did not exceed 2.72 log10 CFU/g and averaged 1.98 log10 CFU/g; spores did not exceed 2.00 log10 CFU/g and averaged 1.56 log10 CFU/g. Raw bologna (70% chicken), chunked ham with emulsion, and whole-muscle ham product mixtures were inoculated with C. perfringens spores (ATCC 12916, ATCC 3624, FD1041, and two product isolates) to ca. 3.0 log10 CFU/g before being subjected either to thermal processes mimicking cooking and chilling regimes determined by in-plant temperature probing or to cooking and extended chilling regimes. Populations of C. perfringens were recovered on SFP from each product at the peak cook temperatures, at 54.4, 26.7, and 7.2 degrees C, and after up to 14 days of storage under vacuum at 4.4 degrees C. In each product, populations remained relatively unchanged during chilling from 54.4 to 7.2 degrees C and declined slightly during refrigerated storage. These findings indicate processed meat products cured with sodium nitrite are not at risk for the growth of C. perfringens during extended chilling and cold storage. PMID:12540184

Taormina, Peter J; Bartholomew, Gene W; Dorsa, Warren J

2003-01-01

259

Toxin-associated and other genes in Clostridium perfringens type A isolates from bovine clostridial abomasitis (BCA) and jejunal hemorrhage syndrome (JHS).  

PubMed

This study examined known or possible virulence-associated genes in type A Clostridium perfringens from cases of both bovine clostridial abomasitis (BCA) and jejunal hemorrhage syndrome (JHS) and compared these to isolates from calves that were healthy or had undifferentiated diarrheal illness. A real-time polymerase chain reaction (PCR) assay was used to genotype the 218 C. perfringens isolates. Isolates were sourced from healthy and diarrheic young and mature cattle (n = 191), from calves with confirmed or suspected BCA (n = 22), and from mature cattle with JHS (n = 5). Of 216 isolates (96%), 208 were positive for the cpa gene and 13% (29/218) were positive for atypical cpb2. Three of 8 (37.5%) confirmed BCA isolates, 2 of 13 (15.4%) suspected BCA isolates, and no JHS isolates tested positive for atypical cpb2. As all isolates were negative for cpb, cpb2, cpe, etx, netB, and tpeL, the results of the present study do not support a role for these genes in BCA or JHS. A subset of unique genes identified in 1 bovine clostridial abomasitis isolate (F262), for which a genome sequence is available, was searched for in 8 BCA isolates by PCR. None of the 10 genes was consistently present in all or even in a majority of BCA isolates. Many of these genes were also variably and inconsistently present in type A isolates from calves that did not have BCA. Although a virulence signature to aid in the diagnosis of BCA caused by C. perfringens type A was not identified, further work may discover a gene or group of genes that would constitute such a signature. PMID:23543949

Schlegel, Benjamin J; Nowell, Victoria J; Parreira, Valeria R; Soltes, Glenn; Prescott, John F

2012-10-01

260

Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica.  

PubMed

McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered. PMID:15574926

Lisle, John T; Smith, James J; Edwards, Diane D; McFeters, Gordon A

2004-12-01

261

Characterization of Acp, a peptidoglycan hydrolase of Clostridium perfringens with N-acetylglucosaminidase activity that is implicated in cell separation and stress-induced autolysis.  

PubMed

This work reports the characterization of the first known peptidoglycan hydrolase (Acp) produced mainly during vegetative growth of Clostridium perfringens. Acp has a modular structure with three domains: a signal peptide domain, an N-terminal domain with repeated sequences, and a C-terminal catalytic domain. The purified recombinant catalytic domain of Acp displayed lytic activity on the cell walls of several Gram-positive bacterial species. Its hydrolytic specificity was established by analyzing the Bacillus subtilis peptidoglycan digestion products by coupling reverse phase-high-pressure liquid chromatography (RP-HPLC) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis, which displayed an N-acetylglucosaminidase activity. The study of acp expression showed a constant expression during growth, which suggested an important role of Acp in growth of C. perfringens. Furthermore, cell fractionation and indirect immunofluorescence staining using anti-Acp antibodies revealed that Acp is located at the septal peptidoglycan of vegetative cells during exponential growth phase, indicating a role in cell separation or division of C. perfringens. A knockout acp mutant strain was obtained by using the insertion of mobile group II intron strategy (ClosTron). The microscopic examination indicated a lack of vegetative cell separation in the acp mutant strain, as well as the wild-type strain incubated with anti-Acp antibodies, demonstrating the critical role of Acp in cell separation. The comparative responses of wild-type and acp mutant strains to stresses induced by Triton X-100, bile salts, and vancomycin revealed an implication of Acp in autolysis induced by these stresses. Overall, Acp appears as a major cell wall N-acetylglucosaminidase implicated in both vegetative growth and stress-induced autolysis. PMID:20190047

Camiade, Emilie; Peltier, Johann; Bourgeois, Ingrid; Couture-Tosi, Evelyne; Courtin, Pascal; Antunes, Ana; Chapot-Chartier, Marie-Pierre; Dupuy, Bruno; Pons, Jean-Louis

2010-02-26

262

Clostridium perfringens alpha-toxin induces the release of IL-8 through a dual pathway via TrkA in A549 cells.  

PubMed

A characteristic feature of gas gangrene with Clostridium perfringens (C. perfringens) is the absence of neutrophils within the infected area and the massive accumulation of neutrophils at the vascular endothelium around the margins of the necrotic region. Intravenous injection of C. perfringens alpha-toxin into mice resulted in the accumulation of neutrophils at the vascular endothelium in lung and liver, and release of GRO/KC, a member of the CXC chemokine family with homology to human interleukin-8 (IL-8). Alpha-toxin triggered activation of signal transduction pathways causing mRNA expression and production of IL-8, which activates migration and binding of neutrophils, in A549 cells. K252a, a tyrosine kinase A (TrkA) inhibitor, and siRNA for TrkA inhibited the toxin-induced phosphorylation of TrkA and production of IL-8. In addition, K252a inhibited the toxin-induced phosphorylation of extracellular regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). PD98059, an ERK1/2 inhibitor, depressed phosphorylation of ERK1/2 and nuclear translocation of nuclear factor kappa B (NF-?B) p65, but SB203580, a p38 MAPK inhibitor, did not. On the other hand, PD98059 and SB203580 suppressed the toxin-induced production of IL-8. Treatment of the cells with PD98059 resulted in inhibition of IL-8 mRNA expression induced by the toxin and that with SB203580 led to a decrease in the stabilization of IL-8 mRNA. These results suggest that alpha-toxin induces production of IL-8 through the activation of two separate pathways, the ERK1/2/NF-?B and p38 MAPK pathways. PMID:22721959

Oda, Masataka; Shiihara, Ryota; Ohmae, Yuka; Kabura, Michiko; Takagishi, Teruhisa; Kobayashi, Keiko; Nagahama, Masahiro; Inoue, Masahisa; Abe, Tomomi; Setsu, Koujun; Sakurai, Jun

2012-06-18

263

Clostridium perfringens enterotoxin is a superantigen reactive with human T cell receptors V beta 6.9 and V beta 22  

PubMed Central

Candidate superantigens were screened for their ability to induce lysis of human histocompatibility leukocyte antigen class II-positive targets by human CD8+ influenza-specific cytotoxic T cell (CTL) lines. Clostridium perfringens enterotoxin (CPET) induced major histocompatibility complex unrestricted killing by some but not all CTL lines. Using "anchored" polymerase chain reactions, CPET was shown to selectively stimulate peripheral blood lymphocytes bearing T cell receptor V beta 6.9 and V beta 22 in five healthy donors. V beta 24, V beta 21, V beta 18, V beta 5, and V beta 6.1-5 appeared to be weakly stimulated. Antigen processing was not required for CPET to induce proliferation. Like the staphylococcal enterotoxins, CPET is a major cause of food poisoning. These data suggest that superantigenic and enterotoxigenic properties may be closely linked.

1992-01-01

264

Hazards associated with Clostridium perfringens in particular reference to predictive models applicable to cooling of cooked meat and poultry products  

Technology Transfer Automated Retrieval System (TEKTRAN)

The incidence of C. perfringens food-poisoning is quite common and costly. Although somewhat fastidious in growth characteristics using synthetic laboratory media, the microorganism is very prolific when found in food products. Inadequate cooling of foods in retail food operations is a major safety ...

265

BBB - Clostridium perfringens  

Center for Food Safety and Applied Nutrition (CFSAN)

... of the causative bacteria in implicated foods or in the feces of patients. ... outbreaks go unreported because the implicated foods or patient feces are ... More results from www.fda.gov/food/foodborneillnesscontaminants/causesofillnessbadbugbook

266

Complete Sequencing and Diversity Analysis of the Enterotoxin-Encoding Plasmids in Clostridium perfringens Type A Non-Food-Borne Human Gastrointestinal Disease Isolates†  

PubMed Central

Enterotoxin-producing Clostridium perfringens type A isolates are an important cause of food poisoning and non-food-borne human gastrointestinal diseases, e.g., sporadic diarrhea (SPOR) and antibiotic-associated diarrhea (AAD). The enterotoxin gene (cpe) is usually chromosomal in food poisoning isolates but plasmid-borne in AAD/SPOR isolates. Previous studies determined that type A SPOR isolate F5603 has a plasmid (pCPF5603) carrying cpe, IS1151, and the beta2 toxin gene (cpb2), while type A SPOR isolate F4969 has a plasmid (pCPF4969) lacking cpb2 and IS1151 but carrying cpe and IS1470-like sequences. By completely sequencing these two cpe plasmids, the current study identified pCPF5603 as a 75.3-kb plasmid carrying 73 open reading frames (ORFs) and pCPF4969 as a 70.5-kb plasmid carrying 62 ORFs. These plasmids share an ?35-kb conserved region that potentially encodes virulence factors and carries ORFs found on the conjugative transposon Tn916. The 34.5-kb pCPF4969 variable region contains ORFs that putatively encode two bacteriocins and a two-component regulator similar to VirR/VirS, while the ?43.6-kb pCPF5603 variable region contains a functional cpb2 gene and several metabolic genes. Diversity studies indicated that other type A plasmid cpe+/IS1151 SPOR/AAD isolates carry a pCPF5603-like plasmid, while other type A plasmid cpe+/IS1470-like SPOR/AAD isolates carry a pCPF4969-like plasmid. Tn916-related ORFs similar to those in pCPF4969 (known to transfer conjugatively) were detected in the cpe plasmids of other type A SPOR/AAD isolates, as well as in representative C. perfringens type B to D isolates carrying other virulence plasmids, possibly suggesting that most or all C. perfringens virulence plasmids transfer conjugatively.

Miyamoto, Kazuaki; Fisher, Derek J.; Li, Jihong; Sayeed, Sameera; Akimoto, Shigeru; McClane, Bruce A.

2006-01-01

267

Comparison of the Effects of Clostridium perfringens Type D Culture Supernates in Ligated Intestinal Loops of Goats and Sheep  

Microsoft Academic Search

The1999 W.B. Saunders Company Ltdeffects ofCopyright Clostridium perfringenstype D culture supernates were compared in ligated loops of the small intestine (ileum) and colon of four goat kids and four lambs, the loops being examined histopathologically and electron microscopically 7 h after inoculation. No lesions were observed in the small intestine of any animal, or in control colonic loops. In the

F. A. Uzal; M. Ghoddusi; W. R. Kelly; M. Rozmanec

1999-01-01

268

1H, 15N and 13C backbone and side-chain resonance assignments of a family 32 carbohydrate-binding module from the Clostridium perfringens NagH.  

PubMed

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. PMID:21912839

Grondin, Julie M; Chitayat, Seth; Ficko-Blean, Elizabeth; Boraston, Alisdair B; Smith, Steven P

2011-09-13

269

The effect of two different blends of essential oil components on the proliferation of Clostridium perfringens in the intestines of broiler chickens.  

PubMed

The effect of 2 different blends of essential oils on Clostridium perfringens (Cp) in the intestine and feces of broiler chickens was tested in 6 field trials for each blend. One hundred parts per million of the blends were mixed in a commercial corn-based diet throughout the entire growing period for experimental flocks. Samples from the jejunum, cecum, cloaca, and feces were taken on d 14, 21, and 30 from experimental and control flocks and tested quantitatively for Cp via blood agar plate, litmus milk medium, and ELISA. Blend A reduced (P < or = 0.05) the average Cp concentration in the feces on all sampling days, in the jejunum and cecum on d 14 and 21, and in the cloaca on d 14. Blend B effected a significant reduction of Cp concentration in the jejunum on d 14 and 30 and in the cloaca on d 14. The percentages of specimens from the control group that tested positive for Cp were 83.3% for feces, 88.0% for jejunum and cloaca, and 82.6% for cecum. Specimens from the feces and 3 sections of the intestine were Cp positive in groups treated with blend A (60.8, 64.6, 47.9, and 70.8%) and with blend B (65.9, 63.6, 63.6, and 72.7%). Our results indicate that specific blends of essential oil components can control Cp colonization and proliferation in the gut of broilers and therefore may be of help to prevent problems with Cp and necrotic enteritis. PMID:15109065

Mitsch, P; Zitterl-Eglseer, K; Köhler, B; Gabler, C; Losa, R; Zimpernik, I

2004-04-01

270

Gene expression profiling within the spleen of Clostridium perfringens-challenged Broilers fed antibiotic-medicated and non-medicated diets  

PubMed Central

Background Clostridium perfringens (Cp) is a Gram-positive anaerobic bacterium that causes necrotic enteritis (NE) in poultry when it overgrows in the small intestine. NE disease has previously been controlled through the use of growth-promoting antibiotics. This practice was recently banned in European countries, leading to significantly increased incidence of NE threatening the poultry industry. Control strategies and technology as substitutes to dietary antibiotics are therefore urgently required. To develop the substitutes, it is important to understand host immune responses to Cp infection. However, the knowledge is still lacking. We therefore investigated gene expression profiles within immunologically-relevant tissue, the spleen, in order to identify factors that are involved in immunity to NE and have potential as therapeutic targets. Results Use of a 44 K Agilent chicken genome microarray revealed significant up-regulation of many immune-associated genes in Cp-challenged chickens, including galectin 3, IFNAR1, IgY-receptor, TCR?, granzyme A, and mannose-6-P-R, which were subsequently validated by quantitative PCR assays. Functional annotation of differentially expressed genes was conducted using the High Throughput Gene Ontology Functional Annotation database. Medicated and Non-medicated chickens had similar annotation profiles with cell activities and regulation being the most dominant biological processes following Cp infection. Conclusion Broiler chickens demonstrated an intricate and holistic magnitude of host response to Cp challenge and the development of NE. Although the influence of dietary antibiotics appeared to be less significant than the disease process, both had a considerable impact on the host response. Markers previously identified in intestinal inflammatory diseases of other species, including humans, and indicators of enhanced antibody responses, appeared to be involved in the chicken response to Cp challenge. The significance in host immune responses of immune mediators identified from the present study warrants further studies to verify their functions during NE development and to determine their potential application to control NE disease.

Sarson, Aimie J; Wang, Ying; Kang, Zhumei; Dowd, Scot E; Lu, Yang; Yu, Hai; Han, Yanming; Zhou, Huaijun; Gong, Joshua

2009-01-01

271

Predictive model for growth of Clostridium perfringens during cooling of cooked beef supplemented with NaCl, sodium nitrite and sodium pyrophosphate  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper presents a model for predicting relative growth of C. perfringens in ground beef products at different percentages of salt (0%, 1%, 2% and 3%) and nitrite (0 and 200 ppm). Included in the experiments were different levels of sodium pyrophosphate (SPP). The results of the experiments indic...

272

EFFECT OF SPICES AND ORGANIC ACIDS ON THE GROWTH OF CLOSTRIDIUM PERFRINGENS FROM SPORE INOCULA DURING COOLING OF SOUS-VIDE COOKED GROUND BEEF PRODUCTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heat treatments given to minimally processed food products are not sufficient to kill C. perfringens spores when present. Thus, the heat resistant spores may survive, germinate, outgrow and multiply into high numbers of vegetative cells if the rate and extent of cooling is inadequate. There is a ...

273

Sporulation and Enterotoxin (CPE) Synthesis Are Controlled by the Sporulation-Specific Sigma Factors SigE and SigK in Clostridium perfringens  

Microsoft Academic Search

the forespore. The cell-specific RNA polymerase sigma factors F, E, G, and K coordinate much of the developmental process. The C. perfringens cpe gene, encoding CPE, is transcribed from three promoters, where P1 was proposed to be K dependent, while P2 and P3 were proposed to be E dependent based on consensus promoter recognition sequences. In this study, mutations were

Kathryn H. Harry; Ruanbao Zhou; Lee Kroos; Stephen B. Melville

2009-01-01

274

OCCURRENCE AND CHARACTERIZATION OF SOME CLOSTRIDIUM SPECIES ISOLATED FROM ANIMAL FEEDINGSTUFFS  

Microsoft Academic Search

The aim of this study was to assess the Clostridium species occurrence in animal feedingstuffs and to characterize toxigenicity of Clostridium perfringens isolates obtained. The Clostridium titre 0.0001 was detected in 2.3% of the compound feeds, and in 7.7% of the examined raw materials and the titre 0.001 was detected in 14.8% of the examined animal feedingstuffs. C. perfringens was

KRZYSZTOF KWIATEK; MAGDALENA KOZAK

275

Glycoside Hydrolase Family 89 ?-N-acetylglucosaminidase from Clostridium perfringens Specifically Acts on GlcNAc?1,4Gal?1R at the Non-reducing Terminus of O-Glycans in Gastric Mucin*  

PubMed Central

In mammals, ?-linked GlcNAc is primarily found in heparan sulfate/heparin and gastric gland mucous cell type mucin. ?-N-Acetylglucosaminidases (?GNases) belonging to glycoside hydrolase family 89 are widely distributed from bacteria to higher eukaryotes. Human lysosomal ?GNase is well known to degrade heparin and heparan sulfate. Here, we reveal the substrate specificity of ?GNase (AgnC) from Clostridium perfringens strain 13, a bacterial homolog of human ?GNase, by chemically synthesizing a series of disaccharide substrates containing ?-linked GlcNAc. AgnC was found to release GlcNAc from GlcNAc?1,4Gal?1pMP and GlcNAc?1pNP substrates (where pMP and pNP represent p-methoxyphenyl and p-nitrophenyl, respectively). AgnC also released GlcNAc from porcine gastric mucin and cell surface mucin. Because AgnC showed no activity against any of the GlcNAc?1,2Gal?1pMP, GlcNAc?1,3Gal?1pMP, GlcNAc?1,6Gal?1pMP, and GlcNAc?1,4GlcA?1pMP substrates, this enzyme may represent a specific glycosidase required for degrading ?-GlcNAc-capped O-glycans of the class III mucin secreted from the stomach and duodenum. Deletion of the C-terminal region containing several carbohydrate-binding module 32 (CBM32) domains significantly reduced the activity for porcine gastric mucin; however, activity against GlcNAc?1,4Gal?1pMP was markedly enhanced. Dot blot and ELISA analyses revealed that the deletion construct containing the C-terminal CBM-C2 to CBM-C6 domains binds strongly to porcine gastric mucin. Consequently, tandem CBM32 domains located near the C terminus of AgnC should function by increasing the affinity for branched or clustered ?-GlcNAc-containing glycans. The agnC gene-disrupted strain showed significantly reduced growth on the class III mucin-containing medium compared with the wild type strain, suggesting that AgnC might have an important role in dominant growth in intestines.

Fujita, Masaya; Tsuchida, Akiko; Hirata, Akiko; Kobayashi, Natsumi; Goto, Kohtaro; Osumi, Kenji; Hirose, Yuriko; Nakayama, Jun; Yamanoi, Takashi; Ashida, Hisashi; Mizuno, Mamoru

2011-01-01

276

42 CFR 73.3 - HHS select agents and toxins.  

Code of Federal Regulations, 2011 CFR

...toxins: Abrin Botulinum neurotoxins Botulinum neurotoxin producing species of Clostridium Cercopithecine herpesvirus 1 (Herpes B virus) Clostridium perfringens epsilon toxin Coccidioides posadasii/Coccidioides immitis Conotoxins...

2011-10-01

277

[Simplified preliminary identification of some species of Clostridium].  

PubMed

A dichotomous key is proposed for the identification of eight species of Clostridium: Clostridium botulinum, C. butyricum, C. haemolyticum, C. histolyticum, C. paraperfringens, C. perfringens, C. sporogenes y C. subterminale, on the basis of the Gram staining, catalase production, growth on nutrient agar, glucose utilization, motility test, gelatin hydrolysis, lecithinase production, human blood hemolysis and the test of mice toxicity. PMID:6765625

Rivas, M; Cinto, R O; Frade, A H

1982-01-01

278

Tips to Prevent Illness from Clostridium Perfringens  

MedlinePLUS

... Minimum Cooking Temperatures Food Safety.gov: Clean, Separate, Cook, and Chill CDC’s Division of Foodborne, Waterborne, and Environmental Diseases Estimates of Foodborne Illness in the United States Email page link Print page Get email updates ...

279

Isolation of Nitrofurantoin-Resistant Mutants of Nitroreductase Producing Clostridium sp. Strains from the Human Intestinal Tract  

Microsoft Academic Search

Five spontaneous nitrofurantoin-resistant mutants (one each of Clostridium leptum, Clostridium paraputrifi- cum, two other Clostridium spp. strains from the human intestinal microflora, and Clostridium perfringens ATCC 3626) were selected by growth on a nitrofurantoin-containing medium. All of the Clostridium wild-type and mutant strains produced nitroreductase, as was shown by the conversion of 4-nitrobenzoic acid to 4-aminobenzoic acid. High-performance liquid chromatography

FATEMEH RAFII

1998-01-01

280

Epsilon Aurigae  

NASA Astrophysics Data System (ADS)

The IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists is planning a multi-year project involving the bright star Eps Aur. The project will go beyond simple observing and also include a major data analysis component. The goal is to introduce the participant to the full scientific process from background research to paper writing for a peer-reviewed journal. It begins with a 10 Star Training Program of several types of binary and transient variable stars that are easy to observe from suburban locations with the naked eye. Participants will be trained both in observing and also in basic data analysis of photometric datasets (light curve and period analysis). Eventually it will lead to a capstone project: monitoring the rare and mysterious 2009-2011 eclipse of Epsilon Aurigae. In the summer of IYA 2009, third-magnitude Eps Aur will experience its next eclipse, which occurs every 27.1 years and lasts 714 days, nearly two years. The star is bright enough to be seen with the naked eye from most urban areas. If fully funded, the project will also involve two public workshops on observing and data analysis in the summers of 2009 and 2010, respectively.

Turner, Rebecca; Price, A.; Henden, A.

2009-05-01

281

Monitoring of anti-C. perfringens bacteriophage CpV1 persistence in gastrointestinal tracts of broilers.  

Technology Transfer Automated Retrieval System (TEKTRAN)

A factor limiting promotion of poultry products to the world market is any contamination of birds with pathogens, including Clostridium perfringens. The latter is often accountable for significant economical losses in production of commercial birds because of a possibility of the development of necr...

282

Can {epsilon}{prime}/{epsilon} be supersymmetric  

SciTech Connect

Supersymmetric contributions to {epsilon}{prime}/{epsilon} have been generally regarded as small. We point out, however, that this is based on specific assumptions, such as universal scalar mass, and in general need not be true. Based on (1) hierarchical quark Yukawa matrices protected by flavor symmetry, (2) generic dependence of Yukawa matrices on Polonyi/moduli fields as expected in many supergravity/superstring theories, (3) Cabibbo rotation originating from the down-sector, and (4) phases of order unity, we find the typical supersymmetric contribution to {epsilon}{prime}/{epsilon} to be of order 3 x 10{sup {minus}3} for m = 500 GeV, possibly dominating the reported KTeV Collaboration value {epsilon}{prime}/{epsilon} = (28 {+-} 4.1) x 10{sup {minus}4}. If so, the neutron electric dipole moment is likely to be within the reach of the currently planned experiments.

Masiero, Antonio; Murayama, Hitoshi

1999-06-01

283

INHIBITION OF GROWTH OF ESCHERICHIA COLI, SALMONELLA TYPHIMURIUM, AND CLOSTRIDIA PERFRINGENS ON CHICKEN FEED MEDIA BY LACTOBACILLUS SALIVARIUS AND LACTOBACILLUS PLANTARUM  

Technology Transfer Automated Retrieval System (TEKTRAN)

The two predominant strains of lactobacilli isolated from a botanical probiotic were identified and evaluated to determine their ability to inhibit the in vitro growth of Escherichia coli, Salmonella typhimurium, and Clostridium perfringens on a medium that simulated a normal starter and grower diet...

284

How to measure epsilon'/epsilon with lattice QCD  

SciTech Connect

A pedagogical discussion is given of a lattice calculation of epsilon'. The method is outlined, and preliminary results are presented. They suggest that epsilon'/epsilon may be reduced from previous estimates by 60-70%.

Sharpe, S.R.

1987-04-01

285

Prevalence of cpb2, encoding beta2 toxin, in Clostridium perfringensfield isolates: correlation of genotype with phenotype  

Microsoft Academic Search

Beta2 toxin, encoded by the cpb2 gene, has been implicated in the pathogenesis of porcine, equine and bovine enteritis by type A Clostridium perfringens. By incorporating primers to cpb2 into a multiplex genotyping PCR, we screened 3270 field isolates of C. perfringens. Of these, 37.2% were PCR positive for the cpb2 gene. The majority of isolates from cases of porcine

Dawn M. Bueschel; B. Helen Jost; Stephen J. Billington; Hien T. Trinh; J. Glenn Songer

2003-01-01

286

Unexpected wide substrate specificity of C. perfringens ?-toxin phospholipase C.  

PubMed

Clostridium perfringens phospholipase C (CpPLC), also called ?-toxin, is the main virulence factor for gas gangrene in humans. The lipase activity serves the bacterium to generate lipid signals in the host eukaryotic cell, and ultimately to degrade the host cell membranes. Several previous reports indicated that CpPLC was specific for phosphatidylcholine and sphingomyelin. Molecular docking studies described in this paper predict favorable interactions of the CpPLC active site with other phospholipids, e.g. phosphatidylethanolamine, phosphatidylinositol and, to a lesser extent, phosphatidylglycerol. On the basis of these predictions, we have performed experimental studies showing ?-toxin to degrade all the phospholipids mentioned above. The molecular docking data also provide an explanation for the observed lower activity of CpPCL on sphingomyelin as compared to the glycerophospholipids. PMID:21704605

Urbina, Patricia; Collado, M Isabel; Alonso, Alicia; Goñi, Félix M; Flores-Díaz, Marietta; Alape-Girón, Alberto; Ruysschaert, Jean-Marie; Lensink, Marc F

2011-06-24

287

Isolation of Clostridium absonum and its cultural and biochemical properties.  

PubMed

A new procedure for isolation of Clostridium absonum was devised. Sixtyseven strains of C. absonum were isolated from 135 soil samples, but no strain of C. absonum could be found from human fecal samples. The lecithinase, hemolysin, and lethal toxin in the culture filtrates of this species exhibited low avidity for C. perfringens type A antitoxin. The three activities were inseparable by the present method of purification. A reinvestigation of biochemical properties revealed that incomplete suppression of lecithinase reaction by C. perfringens type A antitoxin and no fermentation of raffinose, melibiose, and starch are useful criteria to differentiate C. absonum from C. perfringens, and that positive, although weak, gelatin liquefaction and fermentation of trehalose are useful to differentiate it from C. paraperfringens. PMID:4357934

Hayase, M; Mitsui, N; Tamai, K; Nakamura, S; Nishida, S

1974-01-01

288

9 CFR 113.454 - Clostridium Perfringens Type C Antitoxin.  

Code of Federal Regulations, 2013 CFR

...proper dilutions prescribed in this test. Such solution shall be made by dissolving 1 gram of peptone and 0.25 gram of sodium chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving at 250 °F. for 25 minutes; and...

2013-01-01

289

9 CFR 113.455 - Clostridium Perfringens Type D Antitoxin.  

Code of Federal Regulations, 2013 CFR

...proper dilutions prescribed in this test. Such solution shall be made by dissolving 1 gram of peptone and 0.25 gram of sodium chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving at 250 °F. for 25 minutes; and...

2013-01-01

290

Quark masses, B-parameters, and CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon}  

SciTech Connect

After a brief introduction to lattice QCD, the author summarizes the results for the light quark masses and the bag parameters B{sub K}, B{sub 6}{sup 1/2}, and B{sub 8}{sup 3/2}. The implications of these results for the standard model estimates of CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon} are also discussed.

Gupta, R.

1998-01-20

291

The Epsilon Calculus  

Microsoft Academic Search

\\u000a Hilbert’s ?-calculus [1,2] is based on an extension of the language of predicate logic by a term-forming operator ?\\u000a \\u000a x\\u000a . This operator is governed by the critical axiom\\u000a \\u000a \\u000a \\u000a \\u000a A(t) ?A(?x\\u000a A(x)),\\u000a \\u000a \\u000a \\u000a where t is an arbitrary term. Within the ?-calculus, quantifiers become definable by $<\\/font\\u000a>x A(x) Û<\\/font\\u000a> A(e<\\/font\\u000a>xA(x))\\\\exists x A(x) \\\\Leftrightarrow A(\\\\epsilon{x}{A(x)}) and \\u000a\\u000a\\u000a\\u000a\\u000a\\u000a\\

Georg Moser; Richard Zach

292

Can {epsilon}{sup {prime} }/{epsilon} be Supersymmetric?  

SciTech Connect

Supersymmetric contributions to {epsilon}{sup {prime}}/{epsilon} have been generally regarded as small. We point out, however, that this is based on specific assumptions, such as universal scalar mass, and in general need not be true. Based on (1) hierarchical quark Yukawa matrices protected by flavor symmetry, (2) generic dependence of Yukawa matrices on Polonyi/moduli fields as expected in many supergravity/superstring theories, (3) Cabibbo rotation originating from the down-sector, and (4) phases of order unity, we find the typical supersymmetric contribution to {epsilon}{sup {prime}}/{epsilon} to be of order 3{times}10{sup {minus}3} for m{sub {tilde q}}=500 GeV , possibly dominating the reported KTeV Collaboration value {epsilon}{sup {prime}}/{epsilon}=(28{plus_minus}4. 1){times}10{sup {minus}4} . If so, the neutron electric dipole moment is likely to be within the reach of the currently planned experiments. {copyright} {ital 1999} {ital The American Physical Society }

Masiero, A. [SISSA, Via Beirut 2-4, 34014 Trieste (Italy)]|[INFN, Sezione di Trieste (Italy); Murayama, H. [Department of Physics, University of California, Berkeley, California 94720 (United States)]|[Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1999-08-01

293

Interpreting Epsilon Aurigae  

SciTech Connect

The eclipsing binary Epsilon Aurigae consists of an F0 supergiant and a cool, mysterious eclipsing companion with an orbital period of 27.1 yr. The light curve of this system reveals two sources of variability: the eclipses themselves and the variation of the supergiant. Photoelectric observations were made with the 38 cm reflector at the Villanova University Observatory. The bright star undergoes semiregular light variations both inside and outside the eclipse, with a characteristic time scale of a few months which are found to correlate extremely well with changes in color index. It appears that these light and color variations arise from pulsations of the supergiant. The light variations are similar to those found for other luminous A-F supergiants. A computer code has been developed to model the eclipse and explore possible configurations of the disk. The properties of the disk appear more consistent with an interpretation as a protoplanetary system than a remnant of mass transfer from the supergiant. 77 refs.

Carroll, S.M.; Guinan, E.F.; Mccook, G.P.; Donahue, R.A. (Villanova Univ., PA (USA) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA) New Mexico State Univ., Las Cruces (USA))

1991-01-01

294

Myonecrosis by Clostridium septicum in a dog, diagnosed by a new multiplex-PCR.  

PubMed

Clostridial myositis is an acute, generally fatal toxemia that is considered to be rare in pet animals. The present report describes an unusual canine clostridial myositis that was diagnosed by a new multiplex-PCR (mPCR) designed for simultaneous identification of Clostridium sordellii, Clostridium septicum, Clostridium perfringens type A, Clostridium chauvoei, and Clostridium novyi type A. A ten-month-old male Rottweiler dog, that had displayed lameness and swelling of the left limb for 12 h, was admitted to a veterinary hospital. The animal was weak, dyspneic and hyperthermic, and a clinical examination indicated the presence of gas and edema in the limb. Despite emergency treatment, the animal died in only a few minutes. Samples of muscular tissue from the necrotic area were aseptically collected and plated onto defibrinated sheep blood agar (5%) in anaerobic conditions. Colonies suggestive of Clostridium spp. were submitted to testing by multiplex-PCR. Impression smears of the tissues, visualized with Gram and also with panoptic stains, revealed long rod-shaped organisms, and specimens also tested positive using the fluorescent antibody technique (FAT). The FAT and mPCR tests enabled a diagnosis of C. septicum myonecrosis in the dog. PMID:22975141

Ribeiro, Márcio Garcia; Silva, Rodrigo Otávio Silveira; Pires, Prhiscylla Sadanã; Martinho, Anna Paula Vitirito; Lucas, Thays Mizuki; Teixeira, Ana Izabel Passarela; Paes, Antonio Carlos; Barros, Claudenice Batista; Lobato, Francisco Carlos Faria

2012-09-10

295

Oral administration of Clostridium butyricum for modulating gastrointestinal microflora in mice.  

PubMed

This study aimed to evaluate the safety of Clostridium butyricum and to investigate the effect of C. butyricum on mice ecosystem in the intestinal tract by way of examining the population of different microorganisms isolated from caecal contents. We firstly evaluated the safety of C. butyricum using acute toxicity test and Ames test. Then forty male BALB/c mice were divided into the following four treatment groups, each consisting of ten mice: normal group, low-dose group, medium-dose group and high-dose group. Caecal contents were removed aseptically, immediately placed into an anaerobic chamber, and dissolved in sterile pre-reduced PBS. The determination of Enterococcus spp., Enterobacter spp., Lactobacillus spp., Bifidobacterium spp. and Clostridium perfringens was analyzed by the spread plate method, cell morphologies and biochemical profiles. The results showed the oral maximum tolerated dose of C. butyricum was more than 10 g/kg body weight in mice and no mutagenicity judged by negative experimental results of Ames test. And in medium- and high-dose groups, the populations of Bifidobacterium spp. and Lactobacillus spp. increased in caecum, as well as the ratios of Bifidobacterium spp. and Lactobacillus spp. to Clostridium perfringens (P < 0.01) as compared with the normal group. This research showed the intake of C. butyricum significantly improved the ecosystem of the intestinal tract in BALB/c mice by increasing the amount of probiotics and reducing the populations of unwanted bacteria. PMID:20711781

Kong, Qing; He, Guo-Qing; Jia, Ji-Lei; Zhu, Qi-Long; Ruan, Hui

2010-08-15

296

Lipolysis-stimulated lipoprotein receptor (LSR) is the host receptor for the binary toxin Clostridium difficile transferase (CDT)  

PubMed Central

Clostridium difficile infection (CDI) causes antibiotic-associated diarrhea and pseudomembranous colitis. Hypervirulent strains of the pathogen, which are responsible for increased morbidity and mortality of CDI, produce the binary actin-ADP ribosylating toxin Clostridium difficile transferase (CDT) in addition to the Rho-glucosylating toxins A and B. CDT depolymerizes the actin cytoskeleton, increases adherence and colonization of Clostridia by induction of microtubule-based cell protrusions and, eventually, causes death of target cells. Using a haploid genetic screen, we identified the lipolysis-stimulated lipoprotein receptor as the membrane receptor for CDT uptake by target cells. Moreover, we show that Clostridium perfringens iota toxin, which is a related binary actin-ADP ribosylating toxin, enters target cells via the lipolysis-stimulated lipoprotein receptor. Identification of the toxin receptors is essential for understanding of the toxin uptake and provides a most valuable basis for antitoxin strategies.

Papatheodorou, Panagiotis; Carette, Jan E.; Bell, George W.; Schwan, Carsten; Guttenberg, Gregor; Brummelkamp, Thijn R.; Aktories, Klaus

2011-01-01

297

A new measurement of CP violation parameter. var epsilon. prime /. var epsilon  

SciTech Connect

The E731 experiment at Fermilab has measured the CP violation parameter Re({var epsilon}{prime}/{var epsilon}) in K{sub L,S}{yields}{pi}{pi} decay. Four decay modes were collected simultaneously to reduce systematic errors. The result is Re({var epsilon}{prime}/{var epsilon})={minus}0.0005 {plus minus} 0.0014 (stat.) {plus minus} 0.0006 (syst.), and gives no evidence for direct CP violation. 7 refs., 3 figs., 1 tab.

Yamanaka, Taku.

1990-01-01

298

Clostridium Difficile Toxin  

MedlinePLUS

... Anxiety , Tips on Blood Testing , Tips to Help Children through Their Medical Tests , and Tips to Help the Elderly through ... Updated). Stool C. difficile toxin. Medlineplus Health Information, Medical ... Centers for Disease Control and Prevention. Clostridium difficile Infections: ...

299

9 CFR 113.112 - Clostridium Perfringens Type D Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2010 CFR

...toxin-antitoxin mixture. A dose of 0.2 ml shall be injected intravenously into each mouse. Conclude the test 24 hours post-injection and record all deaths. (5) Test Interpretation shall be as follows: (i) If any mice inoculated...

2010-01-01

300

9 CFR 113.112 - Clostridium Perfringens Type D Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2010 CFR

...toxin-antitoxin mixture. A dose of 0.2 ml shall be injected intravenously into each mouse. Conclude the test 24 hours post-injection and record all deaths. (5) Test Interpretation shall be as follows: (i) If any mice inoculated...

2009-01-01

301

9 CFR 113.111 - Clostridium Perfringens Type C Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2010 CFR

...toxin-antitoxin mixture. A dose of 0.2 ml shall be injected intravenously into each mouse. Conclude the test 24 hours post-injection and record all deaths. (5) Test Interpretation shall be as follows: (i) If any mice inoculated...

2009-01-01

302

9 CFR 113.111 - Clostridium Perfringens Type C Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2010 CFR

...toxin-antitoxin mixture. A dose of 0.2 ml shall be injected intravenously into each mouse. Conclude the test 24 hours post-injection and record all deaths. (5) Test Interpretation shall be as follows: (i) If any mice inoculated...

2010-01-01

303

Estimating microbial growth parameters from non-isothermal data: A case study with Clostridium perfringens  

Microsoft Academic Search

Microbial growth parameters are usually calculated from the fit of a growth model to a set of isothermal growth data gathered at several temperatures. In principle at least, it is also possible to derive them from non-isothermal (‘dynamic’) growth data. This requires the numerical solution of a rate model whose coefficients are nested terms that include the temperature profile. The

Sarah Smith-Simpson; Maria G. Corradini; Mark D. Normand; Micha Peleg; Donald W. Schaffner

2007-01-01

304

Use of Clostridium perfringens as a fecal indicator to detect intertidal ...  

Treesearch

Description: Human waste disposal is a health concern in many backcountry areas. ... decay for 101 days, indicating its reliability for detecting fecal contamination ... Government employees on official time, and is therefore in the public domain.

305

9 CFR 113.112 - Clostridium Perfringens Type D Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2013 CFR

...each subserial shall be tested for viable bacteria and fungi as provided in § 113.26...sodium chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving...temperature for 1 hour and hold in ice water until injections of mice can be...

2013-01-01

306

9 CFR 113.111 - Clostridium Perfringens Type C Toxoid and Bacterin-Toxoid.  

Code of Federal Regulations, 2013 CFR

...each subserial shall be tested for viable bacteria and fungi as provided in § 113.26...sodium chloride in each 100 ml of distilled water; adjusting the pH to 7.2; autoclaving...temperature for 1 hour and hold in ice water until injections of mice can be...

2013-01-01

307

A probabilistic analysis of Clostridium perfringens growth during food service operations.  

PubMed

The purpose of this study was threefold: first, the study was designed to illustrate the use of data and information collected in food safety surveys in a quantitative risk assessment. In this case, the focus was on the food service industry; however, similar data from other parts of the food chain could be similarly incorporated. The second objective was to quantitatively describe and better understand the role that the food service industry plays in the safety of food. The third objective was to illustrate the additional decision-making information that is available when uncertainty and variability are incorporated into the modelling of systems. PMID:11934039

Fazil, Aamir M; Ross, Tom; Paoli, Greg; Vanderlinde, Paul; Desmarchelier, Patricia; Lammerding, Anna M

2002-03-01

308

Molecular dynamics simulations for pure epsilon-CL-20 and epsilon-CL-20-based PBXs.  

PubMed

Molecular dynamics has been employed to simulate the well-known high energy density compound epsilon-CL-20 (hexanitrohexaazaisowurtzitane) crystal and 12 epsilon-CL-20-based PBXs (polymer bonded explosives) with four kinds of typical fluorine polymers, i.e., polyvinylidenedifluoride, polychlorotrifluoroethylene, fluorine rubber (F(2311)), and fluorine resin (F(2314)) individually. The elastic coefficients, isotropic mechanical properties (tensile moduli, bulk moduli, shear moduli, and poission's ratios), and bonding energy are first reported for epsilon-CL-20 crystal and epsilon-CL-20-based polymer bonded explosives (PBXs). The mechanical properties of epsilon-CL-20 can be effectively improved by blending with a small amount of fluorine polymers, and the whole effect of the adding fluorine polymers to improve mechanical properties of PBXs along the three crystalline surfaces of epsilon-CL-20 is found to be (100) approximately (001) > (010). The interaction between each of the crystalline surfaces and each of the fluorine polymers is different, and the ordering of binding energy for the three surfaces is (001) > (100) > (010); F(2314) always has the strongest binding ability with the three different surfaces. F(2314) can best improve the ductibility and tenacity of PBX when it is positioned on epsilon-CL-20 (001) crystal surface. The calculations on detonation performances for pure epsilon-CL-20 crystal and the four epsilon-CL-20-based PBXs show that adding a small amount of fluorine polymer into pure epsilon-CL-20 will lower detonation performance, but each detonation parameter of the obtained PBXs is still excellent. PMID:16599487

Xu, Xiao-Juan; Xiao, He-Ming; Xiao, Ji-Jun; Zhu, Wei; Huang, Hui; Li, Jin-Shan

2006-04-13

309

Prophage Carriage and Diversity within Clinically Relevant Strains of Clostridium difficile  

PubMed Central

Prophages are encoded in most genomes of sequenced Clostridium difficile strains. They are key components of the mobile genetic elements and, as such, are likely to influence the biology of their host strains. The majority of these phages are not amenable to propagation, and therefore the development of a molecular marker is a useful tool with which to establish the extent and diversity of C. difficile prophage carriage within clinical strains. To design markers, several candidate genes were analyzed including structural and holin genes. The holin gene is the only gene present in all sequenced phage genomes, conserved at both terminals, with a variable mid-section. This allowed us to design two sets of degenerate PCR primers specific to C. difficile myoviruses and siphoviruses. Subsequent PCR analysis of 16 clinical C. difficile ribotypes showed that 15 of them are myovirus positive, and 2 of them are also siphovirus positive. Antibiotic induction and transmission electron microscope analysis confirmed the molecular prediction of myoviruses and/or siphovirus presence. Phylogenetic analysis of the holin sequences identified three groups of C. difficile phages, two within the myoviruses and a divergent siphovirus group. The marker also produced tight groups within temperate phages that infect other taxa, including Clostridium perfringens, Clostridium botulinum, and Bacillus spp., which suggests the potential application of the holin gene to study prophage carriage in other bacteria. This study reveals the high incidence of prophage carriage in clinically relevant strains of C. difficile and correlates the molecular data to the morphological observation.

Shan, Jinyu; Patel, Krusha V.; Hickenbotham, Peter T.; Nale, Janet Y.; Hargreaves, Katherine R.

2012-01-01

310

Physical and genetic map of the Clostridium acetobutylicum ATCC 824 chromosome.  

PubMed Central

A physical and genetic map of the Clostridium acetobutylicum ATCC 824 chromosome was constructed. The macrorestriction map for CeuI, EagI, and SstII was created by ordering the 38 restriction sites by one- and two-dimensional pulsed-field gel electrophoresis (PFGE) and by using an original strategy based on the CeuI enzyme and indirect end labelling by hybridization on both sides of the CeuI sites with rrs (16S RNA) and 3' rrl (23S RNA) probes. The circular chromosome was estimated to be 4.15 Mb in size, and the average resolution of the physical map is 110 kb. The chromosome contains 11 rrn loci, which are localized on 44% of the chromosome in a divergent transcriptional orientation regarding the presumed location of the replication origin. In addition to these 11 rrn operons, a total of 40 identified genes were mapped by hybridization experiments with genes from C. acetobutylicum and from various other clostridia as probes. The genetic map of C. acetobutylicum was compared to that of the three other endospore-forming bacteria characterized so far: Bacillus subtilis, Clostridium beijerinckii, and Clostridium perfringens. Parodoxically, the chromosomal backbone of C. acetobutylicum showed more similarity to that of B. subtilis than to those of the clostridia.

Cornillot, E; Croux, C; Soucaille, P

1997-01-01

311

Solubility of (epsilon)-CL-20 in selected materials.  

National Technical Information Service (NTIS)

Solubility of the epsilon polymorph of CL-20 was determined in thirteen liquids over temperature range ambient to 74C using high performance liquid chromatography. The experiments included (epsilon)-CL-20 produced by two different synthesis routes; one lo...

E. von Holtz D. Ornellas M. F. Foltz J. E. Clarkson

1992-01-01

312

Comparison of 3 agar media in Fung double tubes and Petri plates to detect and enumerate Clostridium spp. in broiler chicken intestines.  

PubMed

Clostridium perfringens is an anaerobic, spore-forming bacterium that may lead to necrotic enteritis, resulting in poor feed efficiency and increased mortality in chickens. It is estimated that C. perfringens infects almost 1 million people in the United States every year. The objective of this research was to compare the Fung double tube (FDT) and conventional Petri plates using 3 different media to detect and enumerate Clostridium spp. in chicken intestines. Nine Cobb 500 broilers were randomly selected and euthanized at 21 and 42 d of age for a total of 18 samples. The jejunum and ileum from each broiler were harvested and studied in 2 methods and 3 media combinations, utilizing a 2 × 3 factorial totaling 6 treatments. The 2 methods were FDT and conventional Petri plates, and the 3 media were Shahidi-Ferguson Perfringens (SFP) with egg yolk supplement, polymyxin B, and kanamycin (E); SFP with polymyxin B and kanamycin (P); and SFP with d-cycloserine (C). Enumerations were performed after 24 h of incubation at 37°C. At 21 d, counts using medium C with FDT (4.51 log10 cfu/g) and plates (2.38 log10 cfu/g) were higher (P < 0.05) than using media E or P. On d 42, there were no differences among plate treatments and medium E had the highest counts (0.98 log10 cfu/g). Of all the FDT, medium C (5.35 log10 cfu/g) had the highest counts (P < 0.05), followed by medium P (3.54 log10 cfu/g). This study illustrates that the FDT method is able to enumerate Clostridium spp. at higher levels (P < 0.001) than the conventional Petri plate method; therefore, the FDT should be implemented and further explored. PMID:23687145

Barrios, M A; Saini, J K; Rude, C M; Beyer, R S; Fung, D Y C; Crozier-Dodson, B A

2013-06-01

313

Electrotransformation of Clostridium thermocellum  

Microsoft Academic Search

Electrotransformation of several strains of Clostridium thermocellum was achieved using plasmid pIKm1 with selection based on resistance to erythromycin and lincomycin. A custom-built pulse generator was used to apply a square 10-ms pulse to an electrotransformation cuvette consisting of a modified centrifuge tube. Transformation was verified by recovery of the shuttle plasmid pIKm1 from presumptive transformants of C. thermocellum with

Michael V. Tyurin; Sunil G. Desai; Lee R. Lynd

2004-01-01

314

Clostridium difficile infection  

PubMed Central

Clostridium difficile infection (CDI) is the primary cause of antibiotic-associated diarrhea and is a significant nosocomial disease. In the past ten years, variant toxin-producing strains of C. difficile have emerged, that have been associated with severe disease as well as outbreaks worldwide. This review summarizes current information on C. difficile pathogenesis and disease, and highlights interventions used to combat single and recurrent episodes of CDI.

Viswanathan, VK; Mallozzi, MJ

2010-01-01

315

A DIM CANDIDATE COMPANION TO {epsilon} CEPHEI  

SciTech Connect

Using a vector vortex coronagraph behind the 1.5 m well-corrected subaperture (WCS) at Palomar, we detected a second object very close to {epsilon} Cephei, a {delta} Scuti F0 IV star. The candidate companion, {approx}50 times fainter than {epsilon} Cephei, if physically associated, is a late-type K or early M star, and lies at an angular separation of 330 mas, or 1.1 {lambda}/D for the WCS, making it the smallest angle detection ever realized with a coronagraph in terms of {lambda}/D units. The projected separation of the putative companion is {approx}8.6 AU, most likely on a highly eccentric orbit. The recently detected near-infrared excess is thus likely not due to hot dust. Moreover, we also show that the previously reported IRAS 60 {mu}m excess was due to source confusion on the galactic plane.

Mawet, D. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Mennesson, B.; Serabyn, E.; Stapelfeldt, K. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Absil, O. [Institut d'Astrophysique et de Geophysique de Liege, University of Liege, 17 Allee du 6 Aout, 4000 Sart Tilman (Belgium)

2011-09-01

316

Small Telescope Spectroscopy of Epsilon Aurigae  

NASA Astrophysics Data System (ADS)

With the availability of professional quality and reasonably priced spectrographs such as the Star Analyser, for low-resolution work, and the Lhires III with a 2400 l/mm grating, for high-resolution work, along with easy to learn and use spectral processing software such as RSpec, what was once well beyond the backyard astronomer is now well within the means of the advanced amateur astronomer allowing them to do serious astronomical spectroscopic work. The 27-year eclipse of Epsilon Aurigae is over until 2036, but there is still much going on out-ofeclipse that warrants continued observations. This paper will describe low and high-resolution spectroscopy of Epsilon Aurigae done at the Hopkins Phoenix Observatory. In particular five prominent hydrogen Balmer and sodium D lines will be examined.

Hopkins, Jeffrey L.

2012-05-01

317

Epsilon Negative Zeroth-Order Resonator Antenna  

Microsoft Academic Search

It is confirmed that zeroth-order resonance appears in the epsilon negative (ENG) meta-structured transmission line (MTL) as well as in the conventional double negative (DNG) MTL. The zeroth-order resonant characteristics are described using dispersion relation of ENG MTL based on Bloch and Floquet theory. Appling the novel concept of the ENG zeroth-order resonator (ZOR), an ENG ZOR antenna is proposed.

Jae-Hyun Park; Young-Ho Ryu; Jae-Gon Lee; Jeong-Hae Lee

2007-01-01

318

Longitudinal study of Clostridium difficile and antimicrobial susceptibility of Escherichia coli in healthy horses in a community setting.  

PubMed

Point prevalence studies have reported carriage rates of enteric pathogens in healthy horses, but longitudinal data are lacking. Commensal E. coli is an indicator organism to evaluate antimicrobial resistance of enteric bacteria, yet there are limited data for horses. The objectives of this study were to investigate and molecularly characterize isolates of Clostridium difficile, Clostridium perfringens and Salmonella, collected sequentially over a one year period, and to determine the antibiotic susceptibility profile for E. coli. Fecal samples were collected monthly from 25 adult horses for one year. Selective cultures were performed for all above bacteria. C. difficile isolates were characterized via PCR toxin gene profiling and ribotyping. Broth microdilution was performed to assess antimicrobial susceptibility profiles of E. coli. Toxigenic Clostridium difficile was isolated from 15/275 (5.45%) samples from 10/25 (40%) horses. Four horses were positive at multiple sampling times but different ribotypes were found in three. Ribotypes included 078 (n=6), 001 (n=6) and C (n=3). C. perfringens was not isolated, nor was Salmonella. E. coli was isolated from 232/300 (77%) fecal samples. Resistance to ? 1 and ? 3 antimicrobials was present in 31/232 (13.4%) and 6/232 (2.6%) respectively. Only two horses shed the same strain of toxigenic C. difficile for more than one month, indicating that shedding is transient. The high number of ribotype 078 is consistent with recent emergence of this strain in the local horse population. The low prevalence of antibiotic resistance in commensal E. coli suggests that healthy horses are not likely a major reservoir of resistance for enteric bacteria. PMID:22554764

Schoster, A; Staempfli, H R; Arroyo, L G; Reid-Smith, R J; Janecko, N; Shewen, P E; Weese, J S

2012-04-17

319

Clostridium difficile Infection.  

PubMed

Clostridium difficile is emerging as a common cause of infectious diarrhea. Incidence has increased dramatically since 2000, associated with a new strain that features both increased toxin production and increased resistance to antibiotics. For patients with mild to moderate disease, oral metronidazole is usually the first choice of treatment, and those with severe disease should be treated with vancomycin, with additional intravenous metronidazole in some cases. Fecal microbiota transplantation is a potentially promising therapy for patients with multiple recurrences of C difficile infection. Prevention of nosocomial transmission is crucial to reducing disease outbreaks in health care settings. PMID:23809712

Knight, Christopher L; Surawicz, Christina M

2013-04-24

320

Clostridium difficile Infection  

PubMed Central

Clostridium difficile is the leading cause of hospital-acquired diarrhea in Europe and North America and is a serious re-emerging pathogen. Recent outbreaks have led to increasing morbidity and mortality and have been associated with a new strain (BI/NAP1/027) of C. difficile that produces more toxin than historical strains. With the increasing incidence of C. difficile infection, clinicians have also seen a change in the epidemiology with increased infections in previously low-risk populations. This chapter highlights the current knowledge on C. difficile virulence, human disease, epidemic outbreaks, and optimal treatment strategies.

Heinlen, Latisha; Ballard, Jimmy D.

2010-01-01

321

Latest results on the direct CP violation measurements:. Epsilon. prime /. epsilon  

SciTech Connect

Preliminary results, based on the full data sample from Fermilab-E731 and the combined data sample from CERN-NA31, on the direct'' CP-violation measurements {epsilon}{prime}{epsilon} in neutral kaon decay have been reviewed. The E731's results if Re({epsilon}{prime}{epsilon}) = (6.0 {plus minus} 5.8(stat) {plus minus} 3.2(syst) {plus minus} 1.8(MC)) {times} 10{sup {minus}4}, which provides no evidence for direct'' CP-violation, thus supporting the Superweak model; while the NA31's combined result (1986 + 1988 + 1989 data) is Re({epsilon}{prime}/{epsilon} = (23{plus minus}3.4(stat) {plus minus}6.5(syst)){times}10{sup 4}, three standard deviations from zero, which provides evidence for the direct'' CP-violation in the Standard Model. Comparisons of the two experiments are made. The Fermilab-E731 group has also fit for the other parameters of the neutral kaon system in their 2{pi} data sample, such as: the K{sub S} life time {tau}{sub S}; the K{sub L}-K{sub S} mass difference {delta}m; the phase difference between {eta}{sub +-}, {delta}{phi} = ({minus}0.6{plus minus}1.6){degrees}). Which is a test of CPT invariance; the Superweak phase {phi}{sub SW} = (43.37{plus minus}0.22){degrees}, and the phase of {eta}{sub {plus minus}}, {phi}{sub {plus minus}} = (43.2{plus minus} 1.6){degrees}, which is predicted by CPT invariance to equal {phi}{sub SW}.

Hsiung, Yee B.

1992-03-01

322

Latest results on the direct CP violation measurements: {Epsilon}{prime}/{epsilon}  

SciTech Connect

Preliminary results, based on the full data sample from Fermilab-E731 and the combined data sample from CERN-NA31, on the ``direct`` CP-violation measurements {epsilon}{prime}{epsilon} in neutral kaon decay have been reviewed. The E731`s results if Re({epsilon}{prime}{epsilon}) = (6.0 {plus_minus} 5.8(stat) {plus_minus} 3.2(syst) {plus_minus} 1.8(MC)) {times} 10{sup {minus}4}, which provides no evidence for ``direct`` CP-violation, thus supporting the Superweak model; while the NA31`s combined result (1986 + 1988 + 1989 data) is Re({epsilon}{prime}/{epsilon} = (23{plus_minus}3.4(stat) {plus_minus}6.5(syst)){times}10{sup 4}, three standard deviations from zero, which provides evidence for the ``direct`` CP-violation in the Standard Model. Comparisons of the two experiments are made. The Fermilab-E731 group has also fit for the other parameters of the neutral kaon system in their 2{pi} data sample, such as: the K{sub S} life time {tau}{sub S}; the K{sub L}-K{sub S} mass difference {delta}m; the phase difference between {eta}{sub +-}, {delta}{phi} = ({minus}0.6{plus_minus}1.6){degrees}). Which is a test of CPT invariance; the Superweak phase {phi}{sub SW} = (43.37{plus_minus}0.22){degrees}, and the phase of {eta}{sub {plus_minus}}, {phi}{sub {plus_minus}} = (43.2{plus_minus} 1.6){degrees}, which is predicted by CPT invariance to equal {phi}{sub SW}.

Hsiung, Yee B.; E731 Collaboration

1992-03-01

323

Xylose Fermentation with Clostridium Thermohydrosulfuricum.  

National Technical Information Service (NTIS)

In this study, the fermentation of xylose to ethanol with a thermophilic, strictly anaerobic bacterium, Clostridium thermohydrosulfuricum, was examined. The focus of this investigation was on the physiological parameters which most strongly affect the eco...

A. Mancuso C. R. Wilke H. W. Blanch

1982-01-01

324

Epsilon Aurigae - Intriguing Changes with Phase  

NASA Astrophysics Data System (ADS)

Epsilon Aurigae has baffled generations of astrophysicists, and the need to hold a Special Session about this system arises from the depth and persistence of our bafflement. Although the obvious (dominant) star - an early-F supergiant - is partially eclipsed during its 27-year period such that the overall brightness drops by 1 magnitude in V, the spectrum of the system does not change. That fact is what has made epsilon Aurigae traditionally famous. Moreover, the dark object that moves in front must have gigantic proportions. However, it is not actually true to say that the spectrum does not change. It is still recognizeably an early-F supergiant but it changes significantly during eclipse ingress and egress, in ways that provide invaluable information about the mysterious body that was in front throughout 2010 (and still is). Nothing is yet known regarding the properties or constancy of the dark body, and to that end we have sought new information from the long series of spectra in heritage (photographic) archives. The two richest sets of high-dispersion spectra are from the DAO, dating back to 1972, and Mount Wilson, dating back to 1929, offering resolving power of the order of 50,000 and including both blue and red spectral regions. While both sets cover the 1983 eclipse (as do many independent photometric datasets), the Mount Wilson spectra are unique in their rich cover of the 1956 eclipse, and include some of the 1929 event. We have digitized about 300 plates, and are analysing the information by comparing spectra at all orbital phases with new CCD ones as far as possible. The poster will summarize the findings, which will be described in greater detail during the Special Session on epsilon Aurigae on Tuesday January 11.

Griffin, R. E. M.

2011-01-01

325

Nonlinear models in 2 + epsilon dimensions  

SciTech Connect

The general nonlinear scalar model is studied at asymptotically low temperature near two dimensions. The low-temperature expansion is renormalized, and effective algorithms are derived for calculation to all orders in the renormalized expansion. The renormalization group coefficients are calculated in the two-loop approximation, and topological properties of the renormalization group equations are investigated. Special attention is paid to the infrared instabilities of the fixed points, since they provide the continuum limits of the model. The model consists of a scalar field phi on Euclidean 2 + epsilon space whose values phi(x) lie in a finite-dimensional differentiable manifold. 4 figures.

Friedan, D.H.

1980-08-01

326

Observations of epsilon Cha candidates (Murphy+, 2013)  

NASA Astrophysics Data System (ADS)

Astrometric (positions, proper motions), photometric (IJHKW1-W4, E(B-V)) and spectroscopic (spectral types, radial velocities, lithium, H-alpha) measurements are presented for all proposed members of epsilon Cha. The majority of the spectroscopic data were obtained on the Australian National University 2.3-m telescope at Siding Spring Observatory. Ages, distances and heliocentric positions and velocities are given for the 35 stars confirmed as members by our analysis, as well as 6 provisional members requiring further observations. (5 data files).

Murphy, S. J.; Lawson, W. A.; Bessell, M. S.

2013-09-01

327

Epsilon Aurigae at the End of Eclipse  

NASA Astrophysics Data System (ADS)

We request a small investment of 24 minutes of Spitzer time, to obtain four IRAC observations of epsilon Aurigae. A naked eye object located near Capella, epsilon Aurigae is the eclipsing binary star with the longest known orbital period, showing a single long duration (~2 yr) eclipse every 27.1 yr. For much of the last 150 years, the nature of the eclipsing object defied explanation. We recently demonstrated that epsilon Aurigae consists of a high luminosity F0 post-AGB star in orbit with a B5 V star surrounded by a solar system sized (~8 AU diameter) disk of cool, dust-dominated material. The eclipse of epsilon Aurigae is a rare event; moreover, it is a unique astrophysical opportunity, since the backlighting of the disk by the high luminosity eclipsed star reveals details that cannot be detected in similar dusty disks around single stars. The current eclipse started in August 2009 and is expected to reach its photometric conclusion in May 2011 (with the spectroscopic conclusion as late as December 2011). The goals for these observations include: (1) extend our ongoing IRAC monitoring campaign covering the current eclipse to late-phase and post-eclipse visits; (2) provide a consistent, well-calibrated space-based set of IR photometry for comparison with ongoing ground-based work; and (3) use the composite results to constrain the thermal profile of the disk. A key expectation of these particular observations is to reveal the irradiation-heated portion of the disk, which will be visible on its trailing side following eclipse. Observations of this side of the disk will be crucial to test and constrain new models of disk structure. As part of our overall monitoring campaign with Spitzer, Hubble, Herschel, and numerous ground-based facilities, these proposed observations will make an important contribution to the understanding of stellar evolution in binary stars, including mass transfer and evolution studies, along with new insights into astrophysical disks and post-AGB star evolution.

Hoard, Donald; Stencel, R.; Howell, S.

2011-05-01

328

Revealing the Hot Side of Epsilon Aurigae  

NASA Astrophysics Data System (ADS)

We request a small investment of 24 minutes of Spitzer time, to obtain four IRAC observations of epsilon Aurigae. A naked eye object located near Capella, epsilon Aurigae is the eclipsing binary star with the longest known orbital period, showing a single long duration (~2 yr) eclipse every 27.1 yr. For much of the last 200 years, the nature of the eclipsing object defied explanation. We recently demonstrated that epsilon Aurigae consists of a high luminosity F0 post-AGB star in orbit with a B5 V star surrounded by a solar system sized (~8 AU diameter) disk of cool, dust-dominated material. The eclipse of epsilon Aurigae is a rare event; moreover, it is a unique astrophysical opportunity, since the backlighting of the disk by the high luminosity eclipsed star reveals details that cannot be detected in similar dusty disks around single stars. The current eclipse started in August 2009 and ended in July 2011; we are now in the post-eclipse phase, when the irradiation-heated side of the disk will begin rotating into view. The goals for these observations include: (1) extend our ongoing IRAC monitoring campaign covering the current eclipse to post-eclipse visits; (2) provide a consistent, well-calibrated space-based set of IR photometry for comparison with ongoing ground-based work; and (3) use the composite results to constrain the thermal profile of the disk. A key expectation of these particular observations is to reveal the irradiation-heated portion of the disk, which will be visible on its trailing side following eclipse. Observations of this side of the disk will be crucial to test and constrain new models of disk structure. As part of our overall monitoring campaign with Spitzer, Hubble, Herschel, and numerous ground-based facilities, these proposed observations will make an important contribution to the understanding of stellar evolution in binary stars, including mass transfer and evolution studies, along with new insights into astrophysical disks and post-AGB star evolution.

Hoard, Donald; Stencel, Robert; Howell, Steve

2012-12-01

329

Out of Eclipse Monitoring of Epsilon Aurigae  

NASA Astrophysics Data System (ADS)

Epsilon Aurigae received significant attention during its last eclipse when between 2009-2011 it was occulted by a companion enshrouded in a dark disk. We have continued to observe it to better understand regular changes in the spectrum of the primary star outside eclipse and control against their influence in the in-eclipse spectrum. More than year after the end of the last eclipse, we have identified a few variable spectral features in the primary and also some influence of the dark disk that lingered past the predicted end of the eclipse.

Martin, John C.; Foster, C.; O'Brien, J. A.

2013-01-01

330

Electromagnetic Penguin Contribution to epsilon'/epsilon for Large Top Quark Mass,  

National Technical Information Service (NTIS)

The electromagnetic penguin contribution to epsilon' was evaluated under the assumption that the top quark mass can be large. A significant effect was found for top masses larger than the mass of the W. Other operators are considered which can affect the ...

J. M. Flynn L. Randall

1989-01-01

331

The Final Measurement of Epsilon'/Epsilon from KTeV  

SciTech Connect

The authors present precise measurements of CP and CPT symmetry based on the full dataset of K {yields} {pi}{pi} decays collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This dataset contains about 15 million K {yields} {pi}{sup 0}{pi}{sup 0} and 70 million K {yields} {pi}{sup +}{pi}{sup -} decays. They measure the direct CP violation parameter Re({epsilon}'/{epsilon}) = (19.2 {+-} 2.1) x 10{sup -4}. they find the K{sub L}-K{sub S} mass difference {Delta}m = (5265 {+-} 10) x 10{sup 6} {bar h}s{sup -1} and the K{sub S} lifetime {tau}{sub S} = (89.62 {+-} 0.05) x 10{sup -12} s. They test CPT symmetry by finding the phase of the indirect CP violation parameter {epsilon}, {phi}{sub {epsilon}} = (44.09 {+-} 1.00){sup o}, and the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K {yields} {pi}{sup +}{pi}{sup -} ({phi}{sub +-}) and for K {yields} {pi}{sup 0}{pi}{sup 0} ({phi}{sub 00}), {Delta}{phi} = (0.29 {+-} 0.31){sup o}. these results are consistent with other experimental results and with CPT symmetry.

Worcester, E.T.

2009-10-01

332

The Final Measurement of Epsilon'/Epsilon from KTeV  

SciTech Connect

We present precise measurements of CP and CPT symmetry based on the full dataset of K {yields} {pi}{pi} decays collected by the KTeV experiment at FNAL. We measure the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) = (19.2 {+-} 2.1) x 10{sup -4}. We find the KL-KS mass difference {Delta}m = (5265 {+-} 10) x 10{sup 6} hs{sup -1} and the K{sub S} lifetime {tau}{sub S} = (89.62 {+-} 0.05) x 10{sup -12} s. We test CPT symmetry by finding the phase of the indirect CP violation parameter {epsilon}, {phi}{sub {epsilon}} = (44.09 {+-} 1.00){sup o}, and the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K {yields} {pi}{sup +}{pi}{sup -} ({phi}{sub {+-}}) and for K {yields} {pi}{sup 0}{pi}{sup 0} ({phi}{sub 00}), {Delta}{phi} = (0.29 {+-} 0.31){sup o}. These results are consistent with other experimental results and with CPT symmetry.

Worcester, E.T.

2009-09-01

333

Genetically encoding N(epsilon)-acetyllysine in recombinant proteins.  

PubMed

N(epsilon)-acetylation of lysine (1) is a reversible post-translational modification with a regulatory role that rivals that of phosphorylation in eukaryotes. No general methods exist to synthesize proteins containing N(epsilon)-acetyllysine (2) at defined sites. Here we demonstrate the site-specific incorporation of N(epsilon)-acetyllysine in recombinant proteins produced in Escherichia coli via the evolution of an orthogonal N(epsilon)-acetyllysyl-tRNA synthetase/tRNA(CUA) pair. This strategy should find wide applications in defining the cellular role of this modification. PMID:18278036

Neumann, Heinz; Peak-Chew, Sew Y; Chin, Jason W

2008-02-17

334

Epsilon-dominating solutions in mean-variance portfolio analysis  

Microsoft Academic Search

In this paper the problem of finding the effcient set of portfolios, in a general constraint set, is replaced by finding a set of epsilon-dominating protfolios, the number of which is determined by the size of epsilon. Algorithms, and associated theory are given, together with some possible modifications.

D. J. White

1998-01-01

335

Synergistic hemolysis phenomenon shown by an alpha-toxin-producing Clostridium perfingens and streptococcal CAMP factor in presumptive streptococcal grouping.  

PubMed

A new phenomenon of synergistic hemolysis by Clostridium perfringens alpha-toxin and the streptococcal CAMP factor on human and guinea pig erythrocytes is described. A possible mode of action of the CAMP factors is suggested. On human blood agar all of the tested isolates of group B streptococci gave an arrowhead-shaped zone of hemolysis; 74% of group A gave a crescent-shaped lytic zone, whereas all isolates of groups C and G and the remaining 26% of group A streptococci gave a bullet-shaped lytic zone. By comparison, in the CAMP test incubated aerobically and anaerobically, 70 and 91%, respectively, of streptococci other than group B gave positive, arrowhead-shaped lytic zones. If all intermediate positive reactions in the CAMP tests were read as negative after aerobic incubation, only 89% of group B streptococci would be properly identified. The synergistic hemolysis phenomenon, using an alpha-toxin-producing C. perfringens and human blood agar, provided a reliable test for presumptive identification of group B streptococci, with promising potential to differentiate in the same test group A streptococci from other groups. PMID:215600

Gubash, S M

1978-11-01

336

Distribution of Clostridium botulinum.  

PubMed Central

The distribution of Clostridium botulinum in the natural environments of Denmark, The Faroe Islands, Iceland, Greenland, and Bangladesh was examined. A total of 684 samples were tested. Type E was found in 90% of samples from the aquatic environment of Denmark, including sediments from young artificial lakes, and in 86% of samples from the marine environment of Greenland. Type E was not found in Danish cultivated soil and woodlands, including cultivated soil from reclaimed sea beds, but type B was frequently demonstrated in these environments. C. botulinum types A, B, or E were found in 2.6% of samples from the environments of the Faroe Islands and Iceland, whereas types C or D were demonstrated in 42% of samples from Bangladesh. The incidence of type E in aquatic sediments was not related to general industrial pollution or a high content of rotting vegetation. Fish or a rich aquatic fauna, on the other hand, appeared to contribute to a high incidence of type E. Based on these findings, it is suggested that type E is a true aquatic organism, because this environment offers the best conditions for survival of the spore in nature. It is further suggested that its presence in aquatic bottom deposits is based on sedimentation after proliferation in the carrion of the aquatic fauna and dissemination by water currents and migrating fish.

Huss, H H

1980-01-01

337

The Effect of Proteolytic Enzymes on the Activation of Cl. Perfringens Prototoxin, Types D and E (Deistvie Proteoliticheskikh Fermentov NA Aktivatsiyu Prototoksinov Cl. Perfringens Tipov D I E).  

National Technical Information Service (NTIS)

A study was made of the action of microbial and fungal proteolytic enzymes on the activation of Cl. perfringens D and E of specified strains. An activating effect of the fungus in microbial proteolytic enzymes on the D and E prototoxins was revealed. The ...

E. P. Zemlyanitskaya K. I. Matveev

1970-01-01

338

Direct activation of phospholipase C-epsilon by Rho.  

PubMed

Unique among the phospholipase C isozymes, the recently identified phospholipase C-epsilon (PLC-epsilon) contains an amino-terminal CDC25 domain capable of catalyzing nucleotide exchange on Ras family GTPases as well as a tandem array of Ras-associating (RA) domains near its carboxyl terminus that are effector binding sites for activated H-Ras and Rap. To determine whether other small GTPases activate PLC-epsilon, we measured inositol phosphate accumulation in COS-7 cells expressing a broad range of GTPase-deficient mutants of Ras superfamily proteins. RhoA, RhoB, and RhoC all markedly stimulated inositol phosphate accumulation in PLC-epsilon-expressing cells. This stimulation matched or exceeded phospholipase activation promoted by co-expression of PLC-epsilon with the known regulators Ras, Galpha12/13, or Gbeta1gamma2. In contrast, little effect was observed with the other Rho family members Rac1, Rac2, Rac3, and Cdc42. Truncation of the two carboxyl-terminal RA domains caused loss of responsiveness to H-Ras but not to Rho. Truncation of PLC-epsilon to remove the CDC25 and pleckstrin homology (PH) domains also did not cause loss of responsiveness to Rho, Galpha12/13, or Gbeta1gamma2. Comparative sequence analysis of mammalian phospholipase C isozymes revealed a unique approximately 65 amino acid insert within the catalytic core of PLC-epsilon not present in PLC-beta, gamma, delta, or zeta. A PLC-epsilon construct lacking this region was no longer activated by Rho or Galpha12/13 but retained regulation by Gbetagamma and H-Ras. GTP-dependent interaction of Rho with PLC-epsilon was illustrated in pull-down experiments with GST-Rho, and this interaction was retained in the PLC-epsilon construct lacking the unique insert within the catalytic core. These results are consistent with the conclusion that Rho family GTPases directly interact with PLC-epsilon by a mechanism independent of the CDC25 or RA domains. A unique insert within the catalytic core of PLC-epsilon imparts responsiveness to Rho, which may signal downstream of Galpha12/13 in the regulation of PLC-epsilon, because activation by both Rho and Galpha12/13 is lost in the absence of this sequence. PMID:12900402

Wing, Michele R; Snyder, Jason T; Sondek, John; Harden, T Kendall

2003-08-04

339

Clostridium fallax infection in poultry  

Microsoft Academic Search

A disease causing high mortality in young chickens following listlessness, inappetence and diarrhoea is described from Malawi. Haemorrhagic enteritis, splenic enlargement and congestion with petechial haemorrhages, and subcutaneous oedema were seen at post mortem.Clostridium fallax was isolated from affected birds. Coccidiosis was a possible predisposing factor.

D. C. Ellwood; R. W. Halliwell

1973-01-01

340

Variability in Optical Spectra of epsilon Orionis  

NASA Astrophysics Data System (ADS)

We present the results of a time series analysis of 130 échelle spectra of epsilon Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of H? (net) and He I ?5876 were measured and radial velocities were obtained from the central absorption of He I ?5876. Temporal variance spectra (TVS) revealed significant wind variability in both H? and He I ?5876. The He I TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both H? and He I, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the He I line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.

Thompson, Gregory B.; Morrison, Nancy D.

2013-04-01

341

EPSILON AURIGAE: AN IMPROVED SPECTROSCOPIC ORBITAL SOLUTION  

SciTech Connect

A rare eclipse of the mysterious object {epsilon} Aurigae will occur in 2009-2011. We report an updated single-lined spectroscopic solution for the orbit of the primary star based on 20 years of monitoring at the CfA, combined with historical velocity observations dating back to 1897. There are 518 new CfA observations obtained between 1989 and 2009. Two solutions are presented. One uses the velocities outside the eclipse phases together with mid-times of previous eclipses, from photometry dating back to 1842, which provide the strongest constraint on the ephemeris. This yields a period of 9896.0 {+-} 1.6 days (27.0938 {+-} 0.0044 years) with a velocity semi-amplitude of 13.84 {+-} 0.23 km s{sup -1} and an eccentricity of 0.227 {+-} 0.011. The middle of the current ongoing eclipse predicted by this combined fit is JD 2,455,413.8 {+-} 4.8, corresponding to 2010 August 5. If we use only the radial velocities, we find that the predicted middle of the current eclipse is nine months earlier. This would imply that the gravitating companion is not the same as the eclipsing object. Alternatively, the purely spectroscopic solution may be biased by perturbations in the velocities due to the short-period oscillations of the supergiant.

Stefanik, Robert P.; Torres, Guillermo; Lovegrove, Justin; Latham, David W.; Zajac, Joseph [Harvard-Smithsonian Center for Astrophysics (CfA), 60 Garden Street, Cambridge, MA 02138 (United States); Pera, Vivian E. [MIT Lincoln Laboratory, 244 Wood Street, Lexington, MA 02420 (United States); Mazeh, Tsevi [Wise Observatory, Tel Aviv University, Tel Aviv 69978 (Israel)], E-mail: rstefanik@cfa.harvard.edu

2010-03-15

342

Multiplex PCR assay for detection of Clostridium perfringens in feces and intestinal contents of pigs and in swine feed  

Microsoft Academic Search

A multiplex polymerase chain reaction (PCR) assay, developed to detect the alpha-toxin and enterotoxin genes (cpa and cpe, respectively) of Clostridiumperfringens, was used to identify enterotoxigenic isolates of this organism from feces and intestinal contents of pigs and from feed samples from pig farms in Iowa. The organism was grown on tryptose-sulfite-cycloserine (TSC) agar, TSC agar without egg-yolk, sheep blood

Rajalakshmi Kanakaraj; D. l. Harris; J. Glenn Songer; B. Bosworth

1998-01-01

343

Salmonella spp., Vibrio spp., Clostridium perfringens , and Plesiomonas shigelloides in Marine and Freshwater Invertebrates from Coastal California Ecosystems  

Microsoft Academic Search

The coastal ecosystems of California are highly utilized by humans and animals, but the ecology of fecal bacteria at the land–sea interface is not well understood. This study evaluated the distribution of potentially pathogenic bacteria in invertebrates from linked marine, estuarine, and freshwater ecosystems in central California. A variety of filter-feeding clams, mussels, worms, and crab tissues were selectively cultured

W. A. Miller; M. A. Miller; I. A. Gardner; E. R. Atwill; B. A. Byrne; S. Jang; M. Harris; J. Ames; D. Jessup; D. Paradies; K. Worcester; A. Melli; P. A. Conrad

2006-01-01

344

N-Acetylglucosamine Recognition by a Family 32 Carbohydrate-Binding Module from Clostridium perfringens NagH  

Microsoft Academic Search

Many carbohydrate-active enzymes have complex architectures comprising multiple modules that may be involved in catalysis, carbohydrate binding, or protein–protein interactions. Carbohydrate-binding modules (CBMs) are a common ancillary module whose function is to promote the adherence of the complete enzyme to carbohydrate substrates. CBM family 32 has been proposed to be one of the most diverse CBM families classified to date,

Elizabeth Ficko-Blean; Alisdair B. Boraston

2009-01-01

345

Energy Transfer by Magnetopause Reconnection and the Substorm Parameter Epsilon.  

National Technical Information Service (NTIS)

An expression for the magnetopause reconnection power based on the dawn-dusk component of the reconnectoin electric field, that reduces to the substorm parameter epsilon for the limit that involved equal geomagnetic (BG) and magnetosheath (BM) and magneto...

W. D. Gonzalez A. L. C. Gonzalez

1983-01-01

346

Cloning and characterization of rat casein kinase 1epsilon.  

PubMed

Genes differentially expressed in the subjective day and night in the rat suprachiasmatic nucleus (SCN) were surveyed by differential display. A gene homologous to human casein kinase 1epsilon (CK1epsilon) was isolated, which initially appeared to be expressed in the suprachiasmatic nucleus (SCN) in a circadian manner. We here describe the cDNA cloning of the rat CK1epsilon and characterization of the protein products. The rCK1epsilon is predominantly expressed in the brain including the SCN, binds and phosphorylates mPer1, mPer2, and mPer3 in vitro, and translocates mPer1 and mPer3, but not mPer2, to the cell nucleus depending on its kinase activity when coexpressed with these Per proteins in COS-7 cells. PMID:10899319

Takano, A; Shimizu, K; Kani, S; Buijs, R M; Okada, M; Nagai, K

2000-07-14

347

Novel System for Efficient Isolation of Clostridium Double-Crossover Allelic Exchange Mutants Enabling Markerless Chromosomal Gene Deletions and DNA Integration  

PubMed Central

Isolation of Clostridium mutants based on gene replacement via allelic exchange remains a major limitation for this important genus. Use of a heterologous counterselection marker can facilitate the identification of the generally rare allelic exchange events. We report on the development of an inducible counterselection marker and describe its utility and broad potential in quickly and efficiently generating markerless DNA deletions and integrations at any genomic locus without the need for auxotrophic mutants or the use of the mobile group II introns. This system is based on a codon-optimized mazF toxin gene from Escherichia coli under the control of a lactose-inducible promoter from Clostridium perfringens. This system is potentially applicable to almost all members of the genus Clostridium due to their similarly low genomic GC content and comparable codon usage. We isolated all allelic-exchange-based gene deletions (ca_p0167, sigF, and sigK) or disruptions (ca_p0157 and sigF) we attempted and integrated a 3.6-kb heterologous DNA sequence (made up of a Clostridium ljungdahlii 2.1-kb formate dehydrogenase [fdh] gene plus a FLP recombination target [FRT]-flanked thiamphenicol resistance marker) into the Clostridium acetobutylicum chromosome. Furthermore, we report on the development of a plasmid system with inducible segregational instability, thus enabling efficient deployment of the FLP-FRT system to generate markerless deletion or integration mutants. This enabled expeditious deletion of the thiamphenicol resistance marker from the fdh integrant strain as well as the sigK deletion strain. More generally, our system can potentially be applied to other organisms with underdeveloped genetic tools.

Al-Hinai, Mohab A.; Fast, Alan G.

2012-01-01

348

The epsilon regime with twisted mass Wilson fermions  

Microsoft Academic Search

We investigate the leading lattice spacing effects in mesonic two-point correlators computed with twisted mass Wilson fermions\\u000a in the epsilon-regime. By generalizing the procedure already introduced for the untwisted Wilson chiral effective theory,\\u000a we extend the continuum chiral epsilon expansion to twisted mass WChPT. We define different regimes, depending on the relative\\u000a power counting for the quark masses and the

Oliver Bär; Silvia Necco; Andrea Shindler

2010-01-01

349

Epsilon-skew-binormal receiver operating characteristic (ROC) curves  

Microsoft Academic Search

In this note we extend the well-known binormal model via implementation of the epsilon-skew-normal (ESN) distribution developed by Mudholkar and Hutson (2000). We derive the equation for the receiver operating characteris- tic (ROC) curve assuming epsilon-skew-binormal (ESBN) model and examine the behavior of the maximum likelihood estimates for estimating the ESBN parameters. We then summarize the results of a simulation

Terry L. Mashtare Jr; Alan D. Hutson

2009-01-01

350

Preparation and characterization of magnetic poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) microspheres.  

PubMed

In this article, nano-magnetite particles (ferrofluid, Fe3O4) were prepared by chemical co-deposition method. A series of biodegradable triblock poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL, PCEC) copolymers were synthesized by ring-opening polymerization method from epsilon-caprolactone (epsilon-CL) initiated by poly(ethylene glycol) diol (PEG) using stannous octoate as catalyst. And the magnetic PCEC composite microspheres were prepared by solvent diffusion method. The properties of the ferrofluid, PCEC copolymer, and magnetic PCEC microspheres were studied in detail by SEM, VSM, XRD, Malvern Laser Particle Sizer, 1H-NMR, GPC, and TG/DTG. Effects of macromolecular weight and concentration of polymer, and the time for ultrasound dispersion on properties of magnetic microspheres were also investigated. The obtained magnetic PCEC microspheres might have great potential application in targeted drug delivery system or cell separation. PMID:17701292

Gou, Ma Ling; Qian, Zhi Yong; Wang, Hui; Tang, Yong Bo; Huang, Mei Juan; Kan, Bing; Wen, Yan Juan; Dai, Mei; Li, Xing Yi; Gong, Chang Yang; Tu, Ming Jing

2007-08-15

351

Infrared Studies of Epsilon Aurigae in Eclipse  

NASA Astrophysics Data System (ADS)

We report here on a series of medium resolution spectro-photometric observations of the enigmatic long period eclipsing binary epsilon Aurigae, during its eclipse interval of 2009-2011, using near-infrared spectra obtained with SpeX on the Infrared Telescope Facility (IRTF), mid-infrared spectra obtained with BASS on AOES and IRTF, MIRSI on IRTF, and MIRAC4 on the MMT, along with mid-infrared photometry using MIRSI on IRTF and MIRAC4 on the MMT, plus 1995-2000 timeframe published photometry and data obtained with Denver's TNTCAM2 at WIRO. The goals of these observations included: (1) comparing eclipse depths with prior eclipse data, (2) confirming the re-appearance of CO absorption bands at and after mid-eclipse, associated with sublimation in the disk, (3) seeking evidence for any mid-infrared solid state spectral features from particles in the disk, and (4) providing evidence that the externally irradiated disk has azimuthal temperature differences. IR eclipse depths appear similar to those observed during the most recent (1983) eclipse, although evidence for post-mid-eclipse disk temperature increase is present, due to F star heated portions of the disk coming into view. Molecular CO absorption returned 57 days after nominal mid-eclipse, but was not detected at mid-eclipse plus 34 days, narrowing the association with differentially heated sub-regions in the disk. Transient He I 10830A absorption was detected at mid-eclipse, persisting for at least 90 days thereafter, providing a diagnostic for the hot central region. The lack of solid-state features in Spitzer Infrared Spectrograph, BASS, and MIRAC spectra to date suggests the dominance of large particles (micron-sized) in the disk. Based on these observations, mid-infrared studies out of eclipse can directly monitor and map the disk thermal changes, and better constrain disk opacity and thermal conductivity.

Stencel, Robert E.; Kloppenborg, Brian K.; Wall, Randall E., Jr.; Hopkins, Jeffrey L.; Howell, Steve B.; Hoard, D. W.; Rayner, John; Bus, Schelte; Tokunaga, Alan; Sitko, Michael L.; Bradford, Suellen; Russell, Ray W.; Lynch, David K.; Hammel, Heidi; Whitney, Barbara; Orton, Glenn; Yanamandra-Fisher, Padma; Hora, Joseph L.; Hinz, Philip; Hoffmann, William; Skemer, Andrew

2011-11-01

352

INFRARED STUDIES OF EPSILON AURIGAE IN ECLIPSE  

SciTech Connect

We report here on a series of medium resolution spectro-photometric observations of the enigmatic long period eclipsing binary epsilon Aurigae, during its eclipse interval of 2009-2011, using near-infrared spectra obtained with SpeX on the Infrared Telescope Facility (IRTF), mid-infrared spectra obtained with BASS on AOES and IRTF, MIRSI on IRTF, and MIRAC4 on the MMT, along with mid-infrared photometry using MIRSI on IRTF and MIRAC4 on the MMT, plus 1995-2000 timeframe published photometry and data obtained with Denver's TNTCAM2 at WIRO. The goals of these observations included: (1) comparing eclipse depths with prior eclipse data, (2) confirming the re-appearance of CO absorption bands at and after mid-eclipse, associated with sublimation in the disk, (3) seeking evidence for any mid-infrared solid state spectral features from particles in the disk, and (4) providing evidence that the externally irradiated disk has azimuthal temperature differences. IR eclipse depths appear similar to those observed during the most recent (1983) eclipse, although evidence for post-mid-eclipse disk temperature increase is present, due to F star heated portions of the disk coming into view. Molecular CO absorption returned 57 days after nominal mid-eclipse, but was not detected at mid-eclipse plus 34 days, narrowing the association with differentially heated sub-regions in the disk. Transient He I 10830A absorption was detected at mid-eclipse, persisting for at least 90 days thereafter, providing a diagnostic for the hot central region. The lack of solid-state features in Spitzer Infrared Spectrograph, BASS, and MIRAC spectra to date suggests the dominance of large particles (micron-sized) in the disk. Based on these observations, mid-infrared studies out of eclipse can directly monitor and map the disk thermal changes, and better constrain disk opacity and thermal conductivity.

Stencel, Robert E.; Kloppenborg, Brian K.; Wall, Randall E. [Department of Physics and Astronomy, University of Denver, Denver, CO 80208 (United States); Hopkins, Jeffrey L. [Hopkins Phoenix Observatory, Phoenix, AZ 85033 (United States); Howell, Steve B. [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Hoard, D. W. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Rayner, John; Bus, Schelte; Tokunaga, Alan [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Sitko, Michael L.; Bradford, Suellen [Department of Physics, Cincinnati University, Cincinnati, OH (United States); Russell, Ray W.; Lynch, David K. [Aerospace Corporation, Los Angeles, CA 90009 (United States); Hammel, Heidi; Whitney, Barbara [Space Science Institute, Boulder, CO 80301 (United States); Orton, Glenn; Yanamandra-Fisher, Padma [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Hora, Joseph L. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hinz, Philip; Hoffmann, William, E-mail: rstencel@du.edu [Steward Observatory, Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); and others

2011-11-15

353

Acetone, isopropanol, and butanol production by Clostridium beijerinckii (syn. Clostridium butylicum) and Clostridium aurantibutyricum  

SciTech Connect

Thirty-four strains representing 15 species of anaerobic bacteria were screened for acetone, isopropanol, and n-butanol (solvent) production. Under our culture conditions, several strains of Clostridium beijerinckii and C. aurantibutyricum produced at least 40 mM n-butanol (C. acetobutylicum strains produced up to 41 mM n-butanol under similar conditions). Both solvent-producing and non-solvent-producing strains of C. beijerinckii have high DNA homology with a reference strain of C. beijerinckii. Strains labeled ''Clostridium butylicum'' are phenotypically similar to C. beijerinckii and showed at least 78% DNA homology to a reference strain of C. beijerinckii. Therefore, these ''C. butylicum'' strains are members of C. beijerinckii. An earlier DNA homology study has shown that C. beijerinckii, C. aurantibutyricum, and C. acetobutylicum are distinct species.

George, H.A.; Johnson, J.L.; Moore, W.E.C.; Holdeman, L.V.; Chen, J.S.

1983-03-01

354

Acetone, isopropanol, and butanol production by Clostridium beijerinckii (syn. Clostridium butylicum) and Clostridium aurantibutyricum  

Microsoft Academic Search

Thirty-four strains representing 15 species of anaerobic bacteria were screened for acetone, isopropanol, and n-butanol (solvent) production. Under our culture conditions, several strains of Clostridium beijerinckii and C. aurantibutyricum produced at least 40 mM n-butanol (C. acetobutylicum strains produced up to 41 mM n-butanol under similar conditions). Both solvent-producing and non-solvent-producing strains of C. beijerinckii have high DNA homology with

H. A. George; J. L. Johnson; W. E. C. Moore; L. V. Holdeman; J. S. Chen

1983-01-01

355

Analysis of the expression, localization and activity of rat casein kinase 1epsilon-3.  

PubMed

Casein kinase 1epsilon (CK1epsilon) is a serine/threonine protein kinase that has been suggested to participate in the regulation of various signaling pathways. In this report, we examined the tissue distributions of three putative alternatively spliced forms of rCk1epsilon by RT-PCR. This analysis confirmed that all three isoforms are expressed in rat tissues with different tissue-specific expression patterns. Immunohistochemical analysis showed that the intracellular distribution of rCK1epsilon-3 in neurons was broader than that of rCK1epsilon-1. Moreover, the kinase activity of the rCK1epsilon-3 protein differed from that of rCK1epsilon-1. These data suggest that rCK1epsilon-1 and rCK1epsilon-3 may play different functional roles. PMID:15194874

Takano, Atsuko; Hoe, Hyang-Sook; Isojima, Yasushi; Nagai, Katsuya

2004-06-28

356

Binary Bacterial Toxins: Biochemistry, Biology, and Applications of Common Clostridium and Bacillus Proteins  

PubMed Central

Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic “A-B” paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The “B” components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated “B” components form homoheptameric rings that subsequently dock with an “A” component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, “A” molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria.

Barth, Holger; Aktories, Klaus; Popoff, Michel R.; Stiles, Bradley G.

2004-01-01

357

Epsilon-Near-Zero Mode for Active Optoelectronic Devices  

NASA Astrophysics Data System (ADS)

The electromagnetic modes of a GaAs quantum well between two AlGaAs barriers are studied. At the longitudinal optical phonon frequency, the system supports a phonon polariton mode confined in the thickness of the quantum well that we call epsilon-near-zero mode. This epsilon-near-zero mode can be resonantly excited through a grating resulting in a very large absorption localized in the single quantum well. We show that the reflectivity can be modulated by applying a voltage. This paves the way to a new class of active optoelectronic devices working in the midinfrared and far infrared at ambient temperature.

Vassant, S.; Archambault, A.; Marquier, F.; Pardo, F.; Gennser, U.; Cavanna, A.; Pelouard, J. L.; Greffet, J. J.

2012-12-01

358

Regulation of toxin synthesis in Clostridium botulinum and Clostridium tetani.  

PubMed

Botulinum and tetanus neurotoxins are structurally and functionally related proteins that are potent inhibitors of neuroexocytosis. Botulinum neurotoxin (BoNT) associates with non-toxic proteins (ANTPs) to form complexes of various sizes, whereas tetanus toxin (TeNT) does not form any complex. The BoNT and ANTP genes are clustered in a DNA segment called the botulinum locus, which has different genomic localization (chromosome, plasmid, phage) in the various Clostridium botulinum types and subtypes. The botulinum locus genes are organized in two polycistronic operons (ntnh-bont and ha/orfX operons) transcribed in opposite orientations. A gene called botR lying between the two operons in C. botulinum type A encodes an alternative sigma factor which regulates positively the synthesis of BoNT and ANTPs at the late exponential growth phase and beginning of the stationary phase. In Clostridium tetani, the gene located immediately upstream of tent encodes a positive regulatory protein, TetR, which is related to BotR. C. botulinum and C. tetani genomes contain several two-component systems and predicted regulatory orphan genes. In C. botulinum type A, four two-component systems have been found that positively or negatively regulate the synthesis of BoNT and ANTPs independently of BotR/A. The synthesis of neurotoxin in Clostridia seems to be under the control of complex network of regulation. PMID:23769754

Connan, Chloé; Denève, Cécile; Mazuet, Christelle; Popoff, Michel R

2013-06-13

359

Epsilon Aurigae, 2009: The Eclipse Begins - Observing Campaign Status  

Microsoft Academic Search

The eclipse of 3rd magnitude epsilon Aurigae is forecast to begin during August 2009, reaching totality by year's end, based on all fsix prior eclipse events studied - 1982, 1955, 1930, 1902, 1874 and 1847. We have organized a campaign during the past several years in order to raise awareness about this rare opportunity, and to promote reporting of observations

Robert E. Stencel; Jeffrey L. Hopkins

2009-01-01

360

Energy Transfer by Magnetopause Reconnection and the Substorm Parameter Epsilon.  

National Technical Information Service (NTIS)

An expression for the magnetopause reconnection power based on the dawn-dusk component of the reconnection electric field, that reduces to the substorm parameter epsilon for the limit that involves equal geomagnetic (B sub(G)) and magnetosheath (B sub(M))...

W. D. Gonzalez-Alarcon A. L. C. Gonzalez

1983-01-01

361

Exploring the epsilon regime with twisted mass fermions  

Microsoft Academic Search

In this proceeding contribution we report on a first study in order to explore the so called epsilon regime with Wilson twisted mass (Wtm) fermions. To show the potential of this approach we give a preliminary determination of the chiral condensate.

K. Jansen; A. Nube; A. Shindler; C. Urbach; U. Wenger

2007-01-01

362

VHH Activators and Inhibitors for Protein Kinase C Epsilon  

Microsoft Academic Search

Protein kinase C epsilon (PKC?), which is one of the novel PKC isozymes, is widely expressed throughout the body and has important roles in the function of the nervous, cardiovascular and immune systems. In order to better understand PKC? regulated pathways, isozyme specific activity modulators are desperately needed. Such compounds could also be developed into drugs for diseases such as

M. M. I. Summanen

2012-01-01

363

Formate Dehydrogenase from Clostridium acidiurici  

PubMed Central

Partial purification of formate dehydrogenase from Clostridium acidiurici has been accomplished, and some properties of the enzyme have been determined. The molecular weight of the protein is at least 200,000 daltons. The enzyme showed marked instability to freezing and thawing and was inhibited strongly by oxygen and by light. Such inhibition was not reversed by incubation in the presence of thiol compounds. Cyanide inhibited the enzyme 90% at 0.1 mm concentrations, but ethylenediaminetetraacetate produced only slight inhibition at concentrations as high as 50 mm. The purified enzyme showed no ferredoxin activity in the Clostridium pasteurianum clastic system during pyruvate oxidation. Crude preparations of the enzyme could be coupled through ferredoxin to the reduction of nicotinamide adenine dinucleotide during formate oxidation, but the purified enzyme could not catalyze the reduction of pyridine nucleotides by formate in the presence of ferredoxin. Formate oxidation with the purified enzyme was readily coupled to benzyl viologen reduction, in which case ferredoxin was not required. An exchange between formate and bicarbonate was catalyzed by both crude and purified preparations of the enzyme, but the net synthesis of formate from CO2 was not accomplished.

Kearny, James J.; Sagers, Richard D.

1972-01-01

364

Association of apolipoprotein E allele {epsilon}4 with late-onset sporadic Alzheimer`s disease  

SciTech Connect

Apolipoprotein E, type {epsilon}4 allele (ApoE {epsilon}4), is associated with late-onset sporadic Alzheimer`s disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for {epsilon}4 allele frequencies). These data support the involvement of ApoE {epsilon}4 allele as a very important risk factor for the clinical expression of AD. 22 refs., 1 fig., 3 tabs.

Lucotte, G.; David, F.; Berriche, S. [Regional Center of Neurogenetics, Reims (France)] [and others

1994-09-15

365

Clostridium thermosaccharolyticum strain deficient in acetate production.  

PubMed Central

A mutant of Clostridium thermosaccharolyticum that is blocked in acetate production was isolated after treatment with nitrosoguanidine and selection for fluoroacetate resistance. The mutant produced more ethanol than the parent strain did.

Rothstein, D M

1986-01-01

366

TEM Observation of Stress-Induced epsilon Martensite in a Fe-Mn-Si Alloy.  

National Technical Information Service (NTIS)

The morphology and gamma/epsilon interface structure of stress-induced epsilon martensite have been investigated by transmission electron microscopy in a Fe-29.5wt%Mn-5.8wt%Si shape memory alloy. The stress-induced epsilon martensite is thin plate morphol...

Z. Ji J. Ying D. Z. Yang

1994-01-01

367

Clostridium acetobutylicum protoplast formation and regeneration  

SciTech Connect

Clostridium acetobutylicum is already used for the industrial production of acetone and butanol from molasses. Further advantages include its ability to utilize pentose sugars and produce a carboxymethyl cellulase and a cellobiase. The development of genetic transfer systems enabling the use of genetic manipulation techniques would greatly enhance the potential of the fermentation system. Techniques and media for the production and regeneration of stable Clostridium acetobutylicum protoplasts are described. (Refs. 12).

Allcock, E.R.; Reid, S.J.; Jones, D.T.; Woods, D.R.

1982-03-01

368

New techniques for growing anaerobic bacteria: Experiments with Clostridium butyricum and Clostridium acetobutylicum  

Microsoft Academic Search

Stable membrane fragments derived from Escherichia coli produce and maintain strict anaerobic conditions when added to liquid or solid bacteriological media. Techniques for growing Clostridium butyricum and Clostridium acetobutylicum in membrane containing media are described. Liquid cultures initiated by very small inocula can be grown in direct contact with air. In solid media, colonies develop rapidly from individual cells even

H. I. Adler; W. D. Crow; C. T. Hadden; J. Hall; R. Machanoff

1983-01-01

369

New techniques for growing anaerobic bacteria: experiments with Clostridium butyricum and Clostridium acetobutylicum  

Microsoft Academic Search

Stable membrane fragments derived from Escherichia coli produce and maintain strict anaerobic conditions when added to liquid or solid bacteriological media. Techniques for growing Clostridium butyricum and Clostridium acetobutylicum in membrane-containing media are described. Liquid cultures initiated by very small inocula can be grown in direct contact with air. In solid media, colonies develop rapidly from individual cells even without

H. I. Adler; W. D. Crow; C. T. Hadden; J. Hall; R. Machanoff

1983-01-01

370

Clostridium difficile colitis: a review.  

PubMed

Clostridium difficile has become an increasingly important nosocomial pathogen and is one of the most common causes of hospital-acquired diarrhea. The incidence of C difficile infection (CDI) is increasing worldwide. Overuse of antibiotics is felt to be a major contributing factor leading to the increased incidence of CDI. The clinical manifestations of CDI vary from a mild form of the disease to fulminant diarrhea, leading to significant patient morbidity and mortality. The increasing incidence of CDI has a major impact on increasing health care costs. This article will summarize the epidemiology, pathogenesis, clinical manifestations, laboratory diagnosis, and treatment options for CDI, as well as infection-control measures for the prevention of CDI. PMID:22406889

Moudgal, Varsha; Sobel, Jack D

2012-02-01

371

Clostridium difficile enteritis after colectomy.  

PubMed

Clostridium difficile infection of the colon is, unfortunately, a relatively common occurrence that typically follows treatment with antibiotics; however, C. difficile infection of the small bowel is a much more rare phenomenon with only 19 cases reported to date. We present three cases of isolated C. difficile enteritis after colectomy. Although all three patients were identified early and successfully treated with medical management without the need for surgical intervention, previous authors have suggested a much higher morbidity and mortality rate with this infection. This article reviews the current available literature on C. difficile enteritis to highlight this potentially serious condition in postoperative colectomy patients who present with low-grade fevers, abdominal or pelvic pain, and increased ileostomy output. PMID:19999913

Causey, M Wayne; Spencer, Michael P; Steele, Scott R

2009-12-01

372

Xylanolytic Activity of Clostridium acetobutylicum  

PubMed Central

Of 20 strains of Clostridium spp. screened, 17 hydrolyzed larch wood xylan. Two strains of Clostridium acetobutylicum, NRRL B527 and ATCC 824, hydrolyzed xylan but failed to grow on solid media with larch xylan as the sole carbon source; however, strain ATCC 824 was subsequently found to grow on xylan under specified conditions in a chemostat. These two strains possessed cellulolytic activity and were therefore selected for further studies. In cellobiose-limited continuous cultures, strain NRRL B527 produced maximum xylanase activity at pH 5.2. Strain ATCC 824 produced higher xylanase, xylopyranosidase, and arabinofuranosidase activities in chemostat culture with xylose than with any other soluble carbon source as the limiting nutrient. The activities of these enzymes were markedly reduced when the cells were grown in the presence of excess glucose. The xylanase showed maximum activity at pH 5.8 to 6.0 and 65°C. The enzyme was stable on the alkaline side of pH 5.2 but was unstable below this pH value. The extracellular xylanolytic activity from strain ATCC 824 hydrolyzed 12% of the larch wood xylan during a 24-h incubation period, yielding xylose, xylobiose, and xylotriose as the major hydrolysis products. Strain ATCC 824, after being induced to grow in batch culture in xylan medium supplemented with a low concentration of xylose, failed to grow reproducibly in unsupplemented xylan medium. A mutant obtained by mutagenesis with ethyl methanesulfonate was able to grow reproducibly in batch culture on xylan. Both the parent strain and the mutant were able to grow with xylan as the sole source of carbohydrate in continuous culture with the pH maintained at either 5.2 or 6.0. Under these conditions, the cells utilized approximately 50% of the xylan. Images

Lee, Song F.; Forsberg, Cecil W.; Gibbins, L. N.

1985-01-01

373

The epsilon-sarcoglycan gene in myoclonic syndromes.  

PubMed

Mutations in the epsilon-sarcoglycan gene (SGCE) are associated with familial myoclonus dystonia, but the full spectrum of the phenotype may not be fully defined. We screened 58 individuals with a range of myoclonic/dystonic syndromes for SGCE mutations. We found mutations (three of them novel) in six (21%) of the 29 patients with essential myoclonus and myoclonic dystonia, but did not find mutations in the 29 patients with other phenotypes. PMID:15728306

Valente, E M; Edwards, M J; Mir, P; DiGiorgio, A; Salvi, S; Davis, M; Russo, N; Bozi, M; Kim, H-T; Pennisi, G; Quinn, N; Dallapiccola, B; Bhatia, K P

2005-02-22

374

Eutectic epsilon-near-zero metamaterial terahertz waveguides.  

PubMed

We present and analyze the unique phenomena of enhanced THz transmission through a subwavelength LiF dielectric rod lattice embedded in an epsilon-near-zero KCl host. Our experimental results in combination with theoretical calculations show that subwavelength waveguiding of terahertz radiation is achieved within an alkali-halide eutectic metamaterial as result of the coupling of Mie-resonance modes arising in the dielectric lattice. PMID:23546270

Massaouti, M; Basharin, A A; Kafesaki, M; Acosta, M F; Merino, R I; Orera, V M; Economou, E N; Soukoulis, C M; Tzortzakis, S

2013-04-01

375

Extracting epsilon and mu of materials from vector reflection measurements  

NASA Astrophysics Data System (ADS)

A method has been devised from simultaneously extracting perimittivity epsilon and permeability mu of nonmetallic solids over a wide range of frequencies, based on one-port reflection measurements made by an automatic network analyzer. Reflection measurements are taken of a short, an offset short-circuited air line of length lo, and two short-circuited samples of lengths l and nl, where n is any integer greater than 1. The information contained in these four measurements is sufficient to extract epsilon and mu without recourse to any a priori knowledge of the waveguide's cross section, dispersion, or loss. This method is convenient for measuring epsilon and mu at temperatures significantly different from ambient and in waveguide cross sections whose dispersion and loss are not well known. The presence of higher-order modes and of sample inhomogeneities can be detected from an additional measurement of an offset short-circuited air line. Measurements at Ka-band on polystyrene agree with those of other investigators.

Sequeira, H. B.

1991-03-01

376

Long Term Broadband Polarimetry of Epsilon Aurigae and Field Stars  

NASA Astrophysics Data System (ADS)

The author will present 4 years of broadband polarization measurements of Epsilon Aurigae and field stars. These measurements were obtained using a dual beam CCD polarimeter on a 35cm automated telescope with a typical uncertainty of 0.03%. Epsilon Aurigae showed a high level (0.5%) of intrinsic polarimetric activity during the 2009-2011 eclipse and continues to show irregular pulsations at the 0.2% level. This pattern is similar to that reported by J. Kemp et al. for the 1982-1984 eclipse. The origin of the post eclipse pulsations and their duration remains uncertain. Are they an intrinsic feature of the star or are they being generated by interaction with lingering material from the secondary? How much of the total polarization is truly of interstellar origin? In a 1972 paper partially based upon the 1958 work of J. S. Hall, G. V. Coyne reported broadband measurements of Epsilon Aurigae and of a group of nearby field stars in an attempt to characterize the local interstellar polarization. The author will report 2012 observations that show changes in these stars over a long time interval.

Cole, Gary M.

2013-07-01

377

Advanced k-epsilon modeling of heat transfer  

NASA Astrophysics Data System (ADS)

This report describes two approaches to low Reynolds-number k-epsilon turbulence modeling which formulate the eddy viscosity on the wall-normal component of turbulence and a length scale. The wall-normal component of turbulence is computed via integration of the energy spectrum based on the local dissipation rate and is bounded by the isotropic condition. The models account for the anisotropy of the dissipation and the reduced mixing length due to the high strain rates present in the near-wall region. The turbulent kinetic energy and its dissipation rate were computed from the k and epsilon transport equations of Durbin. The models were tested for a wide range of turbulent flows and proved to be superior to other k-epsilon models, especially for nonequilibrium anisotropic flows. For the prediction of airfoil heat transfer, the models included a set of empirical correlations for predicting laminar-turbulent transition and laminar heat transfer augmentation due to the presence of freestream turbulence. The predictions of surface heat transfer were generally satisfactory.

Kwon, Okey; Ames, Forrest E.

1995-07-01

378

Clostridium histolyticum collagenases: a new look at some old enzymes.  

PubMed

Seven collagenases denoted by the letters alpha, beta, gamma, delta, epsilon, zeta and eta have been purified to homogeneity from the culture filtrate of Clostridium histolyticum. All seven enzymes are zinc proteinases that require calcium ions for activity and have essential carboxyl, tyrosyl and lysyl residues. These enzymes can be divided into two classes on the basis of the sequence homologies in their polypeptide chains, as revealed from a comparison of their tryptic digests. This division into classes is also supported by a comparison of their specificities toward peptide substrates, their interaction with substrate-analog inhibitors, and their mode of attack of triple helical collagens. The sequence specificities of these enzymes have been studied in detail. The specificities of the two classes are similar, but complementary. Both classes exhibit both endopeptidase and tripeptidylcarboxypeptidase activities, where the latter is thought to facilitate removal of Gly-X-Y triplets from the C-terminus of collagen fragments. The mode of attack of these collagenases on triple helical type I, II and III collagens is very similar for the enzymes within each class, but different for the two classes. The class I enzymes first hydrolyze loci near the ends of the triple helical domains of these collagen molecules, while the class II enzymes make their initial cleavages in the interior. The sites of these initial cleavages are being sequenced and preliminary results indicate that they do not resemble the tissue collagenase cleavage site with respect to either their imino acid content or distribution. The kinetic parameters for the hydrolysis of type I, II and III collagens have been measured and are similar in magnitude to those for the tissue collagenases. Synthetic peptide substrate-analog inhibitors have been prepared for both classes of collagenases and shown to be transition-state-analog inhibitors. PMID:1336107

Mookhtiar, K A; Van Wart, H E

1992-01-01

379

A Case of Infant Botulism due to Neurotoxigenic Clostridium butyricum Type E Associated with Clostridium difficile Colitis  

Microsoft Academic Search

.   Reported here is the sixth case of intestinal toxemia botulism caused by Clostridium butyricum type E in Italy since 1984. In this case, the patient was concomitantly affected with colitis due to Clostridium difficile toxin. A review of previously reported cases revealed that some of these patients may also have had intestinal toxemia botulism\\u000a associated with Clostridium difficile colitis,

L. Fenicia; L. Da Dalt; F. Anniballi; G. Franciosa; S. Zanconato; P. Aureli

2002-01-01

380

Prevalence of Clostridium spp. and Clostridium difficile in children with acute diarrhea in São Paulo city, Brazil  

Microsoft Academic Search

Species of Clostridium are widely distributed in the environment, inhabiting both human and animal gas- trointestinal tracts. Clostridium difficile is an important pathogen associated with outbreaks of pseudomembranous colitis and other intestinal disorders, such as diarrhea. In this study, the prevalence of Clostridium spp. and C. difficile, from hospitalized children with acute diarrhea, was examined. These children were admitted to

Claudia EA Ferreira; Viviane Nakano; Edison L Durigon; Mario J Avila-Campos

2003-01-01

381

Comparison of linear and nonlinear RNG-based {kappa}-{epsilon} models for incompressible turbulent flows  

SciTech Connect

Linear and nonlinear renormalization group (RNG) {kappa}-{epsilon} models are compared for the prediction of incompressible turbulent flows. The multidimensional finite-volume code KIVA-3 is used to explore the alternative models versus the standard {kappa}-{epsilon} model. Test cases include the classic backward-facing step and the confined co-flow jet flows. The results suggest that the linear RNG {kappa}-{epsilon} model can yield significant improvements over the standard {kappa}-{epsilon} model for recirculatory flows, because of its less dissipative nature. While the nonlinear RNG {kappa}-{epsilon} model can also improve predictions compared to the standard {kappa}-{epsilon} model, its greatly increased cost compared to the linear RNG model renders it less attractive. However, for the case of shear flows, such as for confined co-flow jets, the RNG-based {kappa}-{epsilon} models are in less favorable agreement with experiments compared to the standard {kappa}-{epsilon} model. Overall, it is concluded that combining the claimed universality of the RNG-based {kappa}-{epsilon} model constants with the anisotropies introduced by the nonlinear {kappa}-{epsilon} model cannot enhance predictions of both recirculating and shear incompressible flows.

Papageorgakis, G.C.; Assanis, D.N. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering and Applied Mechanics

1999-01-01

382

Cellulolytic Activity of Clostridium acetobutylicum  

PubMed Central

Clostridium acetobutylicum NRRL B527 and ATCC 824 exhibited extracellular and cell-bound endoglucanase and cellobiase activities during growth in a chemically defined medium with cellobiose as the sole source of carbohydrate. For both strains, the endoglucanase was found to be mainly extracellular (70 to 90%) during growth in continuous or batch cultures with the pH maintained at 5.2, whereas the cellobiase was mainly cell associated (60 to 90%). During continuous cultivation of strain B527 with cellobiose as the limiting nutrient, maximum production of the endoglucanase and cellobiase occurred at pH values of 5.2 and 4.8, respectively. In the carbon-limited continuous cultures, strain 824 produced similar levels of endoglucanase, cellobiosidase, and cellobiase activities regardless of the carbon source used. However, in ammonium- or phosphate-limited cultures, with an excess of glucose, only 1/10 of the endoglucanase was produced, and neither cellobiosidase nor cellobiase activities were detectable. A crude extracellular enzyme preparation from strain B527 hydrolyzed carboxymethylcellulose and phosphoric acid-swollen cellulose readily and microcrystalline cellulose (A vicel) to a lesser extent. Glucose accounted for more than 90% of the reducing sugar produced by the hydrolysis of acid-swollen cellulose and Avicel. Strain B527 did not grow in medium with acid-swollen cellulose as the sole source of carbohydrate, although it grew readily on the products obtained by hydrolyzing the cellulose in vitro with a preparation of extracellular cellulase derived from the same organism.

Lee, Song F.; Forsberg, Cecil W.; Gibbins, L. N.

1985-01-01

383

Epidemiology of Clostridium difficile Infection.  

PubMed

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

Depestel, Daryl D; Aronoff, David M

2013-10-01

384

Overview of Severe Clostridium difficile Infection.  

PubMed

Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus that can produce severe colitis resulting in death. There has been an overall increase in the incidence of Clostridium difficile-associated disease and, particularly, an increase in the more virulent forms of the disease. Treatment of severe C difficile infection includes management of severe sepsis and shock, pathogen-directed antibiotic therapy, and, in selected cases, surgical intervention. Ultimately, prevention is the key to limiting the devastating effects of this microorganism. PMID:24094379

Eaton, Stephen R; Mazuski, John E

2013-08-06

385

Hydrophobicity of Bacillus and Clostridium spores.  

PubMed Central

The hydrophobicities of spores and vegetative cells of several species of the genera Bacillus and Clostridium were measured by using the bacterial adherence to hexadecane assay and hydrophobic interaction chromatography. Although spore hydrophobicity varied among species and strains, the spores of each organism were more hydrophobic than the vegetative cells. The relative hydrophobicities determined by the two methods generally agreed. Sporulation media and conditions appeared to have little effect on spore hydrophobicity. However, exposure of spore suspensions to heat treatment caused a considerable increase in spore hydrophobicity. The hydrophobic nature of Bacillus and Clostridium spores suggests that hydrophobic interactions may play a role in the adhesion of these spores to surfaces.

Wiencek, K M; Klapes, N A; Foegeding, P M

1990-01-01

386

Butanol production from crystalline cellulose by cocultured Clostridium thermocellum and Clostridium saccharoperbutylacetonicum N1-4.  

PubMed

We investigated butanol production from crystalline cellulose by cocultured cellulolytic Clostridium thermocellum and the butanol-producing strain, Clostridium saccharoperbutylacetonicum (strain N1-4). Butanol was produced from Avicel cellulose after it was incubated with C. thermocellum for at least 24 h at 60°C before the addition of strain N1-4. Butanol produced by strain N1-4 on 4% Avicel cellulose peaked (7.9 g/liter) after 9 days of incubation at 30°C, and acetone was undetectable in this coculture system. Less butanol was produced by cocultured Clostridium acetobutylicum and Clostridium beijerinckii than by strain N1-4, indicating that strain N1-4 was the optimal strain for producing butanol from crystalline cellulose in this coculture system. PMID:21764954

Nakayama, Shunichi; Kiyoshi, Keiji; Kadokura, Toshimori; Nakazato, Atsumi

2011-07-15

387

Butanol Production from Crystalline Cellulose by Cocultured Clostridium thermocellum and Clostridium saccharoperbutylacetonicum N1-4 ?  

PubMed Central

We investigated butanol production from crystalline cellulose by cocultured cellulolytic Clostridium thermocellum and the butanol-producing strain, Clostridium saccharoperbutylacetonicum (strain N1-4). Butanol was produced from Avicel cellulose after it was incubated with C. thermocellum for at least 24 h at 60°C before the addition of strain N1-4. Butanol produced by strain N1-4 on 4% Avicel cellulose peaked (7.9 g/liter) after 9 days of incubation at 30°C, and acetone was undetectable in this coculture system. Less butanol was produced by cocultured Clostridium acetobutylicum and Clostridium beijerinckii than by strain N1-4, indicating that strain N1-4 was the optimal strain for producing butanol from crystalline cellulose in this coculture system.

Nakayama, Shunichi; Kiyoshi, Keiji; Kadokura, Toshimori; Nakazato, Atsumi

2011-01-01

388

Myoglobinuria following epsilon-aminocaproic acid (EACA) therapy. Case report.  

PubMed

Myoglobinuria developed in a patient with subarachnoid hemorrhage treated with a course of 1.43 kg of epsilon-aminocaproic acid (EACA) given over 41 days. Review of eight other cases with a variety of medical disorders shows that this effect occurs after at least 4 weeks of taking doses of a minimum of 24 gm EACA per day. The effect seems to be reversible if discovered early. This side-effect should provide impetus for restricting the duration of EACA therapy to periods under 28 days, in doses no higher than 24 gm/day. PMID:7431078

Brodkin, H M

1980-11-01

389

Enhanced superradiance in epsilon-near-zero plasmonic channels  

NASA Astrophysics Data System (ADS)

We describe the possibility of drastically boosting the spontaneous emission of a collection of two-level quantum emitters by embedding them in an epsilon-near-zero (ENZ) environment, consisting of a plasmonic waveguide operated at cutoff. This phenomenon relies on the combination of Purcell enhancement and Dicke superradiance effects, exploiting the large and uniform local density of states in ENZ channels, which is shown to significantly extend the spatial extent of these quantum effects. We envision exciting applications in optical sensing, molecular detection, and low-threshold lasing.

Fleury, Romain; Alù, Andrea

2013-05-01

390

Cellulose fermentation by a coculture of a mesophilic cellulolytic Clostridium and Clostridium acetobutylicum  

Microsoft Academic Search

A coculture of a mesophilic cellulolytic Clostridium with Clostridium acetobutylicum can yield a direct conversion of cellulose into chemicals. In 13 days 30 g\\/l Solka Floc is degraded and fermented into 14 g\\/l butyric acid, 4 g\\/l acetic acid, 3 g\\/l ethanol, and 1 g\\/l butanol. A four times higher rate of cellulose hydrolysis than in pure culture of the

O. Fond; E. Petitdemange; H. Petitdemange; J. M. Engasser

1983-01-01

391

Transformation of heat-treated Clostridium acetobutylicum protoplasts with pUB110 plasmid DNA  

SciTech Connect

Heat treatment of Clostridium acetobutylicum SA-1 protoplasts at 55/sup 0/C for 15 min before transformation resulted in expression in this microorganism of the kanamycin resistance determinant associated with plasmid pUB110. No heat treatment, or heat treatment at 65 or 44/sup 0/C for various time intervals, resulted in no kanamycin resistance transformants being recovered on selective kanamycin-containing regeneration medium. DNase plate assay indicated that treatment at 55/sup 0/C for 15 min completely inactivated the DNase activity associated with SA-1 protoplasts. Treatment of protoplasts at 65 or 55/sup 0/C for various periods under simulated transformation conditions had an inhibitory effect, although prolonged treatment at 55 or 44/sup 0/C appeared to stimulate DNase activity. Inactivation of protoplast-associated DNase activity by heat treatment at 55/sup 0/C for 15 min correlated with successful expression of kanamycin resistance and suggests that an extremely active, heat-sensitive, protoplast-associated DNase may be a factor in the polyethylene glycol-induced transformation of C. acetobutylicum SA-1 protoplasts. Plasmid pUB110 DNA was isolated from C. acetobutylicum SA-1 kanamycin-resistant (Km/sup r/) transformant cultures by a modification of the procedure used for C. perfringens plasmids. Detection of pUB110 DNA was possible only when diethyl pyrocarbonate was incorporated into isolation protocols to inactivate DNase activity. Restriction studies further verified the presence of pUB110 DNA in C. acetobutylicum SA-1 Km/sup r/ transformants. 36 references, 4 figures, 1 table.

Lin, Y.L.; Blaschek, H.P.

1984-10-01

392

Flagellar glycosylation in Clostridium botulinum.  

PubMed

Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417 Da in O-linkage. Bioinformatic analysis of available C. botulinum genomes identified a flagellar glycosylation island containing homologs of genes recently identified in Campylobacter coli that have been shown to be responsible for the biosynthesis of legionaminic acid derivatives. Structural characterization of the carbohydrate moiety was completed utilizing both MS and NMR spectroscopy, and it was shown to be a novel legionaminic acid derivative, 7-acetamido-5-(N-methyl-glutam-4-yl)-amino-3,5,7,9-tetradeoxy-D-glycero-alpha-D-galacto-nonulosonic acid, (alphaLeg5GluNMe7Ac). Electron transfer dissociation MS with and without collision-activated dissociation was utilized to map seven sites of O-linked glycosylation, eliminating the need for chemical derivatization of tryptic peptides prior to analysis. Marker ions for novel glycans, as well as a unique C-terminal flagellin peptide marker ion, were identified in a top-down analysis of the intact protein. These ions have the potential for use in for rapid detection and discrimination of C. botulinum cells, indicating botulinum neurotoxin contamination. This is the first report of glycosylation of Gram-positive flagellar proteins by the 'sialic acid-like' nonulosonate sugar, legionaminic acid. PMID:18671733

Twine, Susan M; Paul, Catherine J; Vinogradov, Evgeny; McNally, David J; Brisson, Jean-Robert; Mullen, James A; McMullin, David R; Jarrell, Harold C; Austin, John W; Kelly, John F; Logan, Susan M

2008-07-30

393

Atypical glycolysis in Clostridium thermocellum.  

PubMed

Cofactor specificities of glycolytic enzymes in Clostridium thermocellum were studied with cellobiose-grown cells from batch cultures. Intracellular glucose was phosphorylated by glucokinase using GTP rather than ATP. Although phosphofructokinase typically uses ATP as a phosphoryl donor, we found only pyrophosphate (PPi)-linked activity. Phosphoglycerate kinase used both GDP and ADP as phosphoryl acceptors. In agreement with the absence of a pyruvate kinase sequence in the C. thermocellum genome, no activity of this enzyme could be detected. Also, the annotated pyruvate phosphate dikinase (ppdk) is not crucial for the generation of pyruvate from phosphoenolpyruvate (PEP), as deletion of the ppdk gene did not substantially change cellobiose fermentation. Instead pyruvate formation is likely to proceed via a malate shunt with GDP-linked PEP carboxykinase, NADH-linked malate dehydrogenase, and NADP-linked malic enzyme. High activities of these enzymes were detected in extracts of cellobiose-grown cells. Our results thus show that GTP is consumed while both GTP and ATP are produced in glycolysis of C. thermocellum. The requirement for PPi in this pathway can be satisfied only to a small extent by biosynthetic reactions, in contrast to what is generally assumed for a PPi-dependent glycolysis in anaerobic heterotrophs. Metabolic network analysis showed that most of the required PPi must be generated via ATP or GTP hydrolysis exclusive of that which happens during biosynthesis. Experimental proof for the necessity of an alternative mechanism of PPi generation was obtained by studying the glycolysis in washed-cell suspensions in which biosynthesis was absent. Under these conditions, cells still fermented cellobiose to ethanol. PMID:23435896

Zhou, Jilai; Olson, Daniel G; Argyros, D Aaron; Deng, Yu; van Gulik, Walter M; van Dijken, Johannes P; Lynd, Lee R

2013-02-22

394

Antibiotic-Associated Diarrhea Caused by Clostridium difficile (Beyond the Basics)  

MedlinePLUS

... in adults (Beyond the Basics) Clostridium difficile and probiotics Clostridium difficile in adults: Clinical manifestations and diagnosis ... diarrhea (C. difficile infection) (The Basics) Patient information: Probiotics (The Basics) Prevention and control of Clostridium difficile ...

395

Composition and primary structure of the F1F0 ATP synthase from the obligately anaerobic bacterium Clostridium thermoaceticum.  

PubMed Central

The subunit composition and primary structure of the proton-translocating F1F0 ATP synthase have been determined in Clostridium thermoaceticum. The isolated enzyme has a subunit composition identical to that of the F1F0 ATP synthase purified from Clostridium thermoautotrophicum (A. Das, D. M. Ivey, and L. G. Ljungdahl, J. Bacteriol. 179:1714-1720, 1997), both having six different polypeptides. The molecular masses of the six subunits were 60, 50, 32, 17, 19, and 8 kDa, and they were identified as alpha, beta, gamma, delta, epsilon, and c, respectively, based on their reactivity with antibodies against the F1 ATPase purified from C. thermoautotrophicum and by comparing their N-terminal amino acid sequences with that deduced from the cloned genes of the C. thermoaceticum atp operon. The subunits a and b found in many bacterial ATP synthases could not be detected either in the purified ATP synthase or crude membranes of C. thermoaceticum. The C. thermoaceticum atp operon contained nine genes arranged in the order atpI (i), atpB (a), atpE (c), atpF (b), atpH (delta), atpA (alpha), atpG (gamma), atpD (beta), and atpC (epsilon). The deduced protein sequences of the C. thermoaceticum ATP synthase subunits were comparable with those of the corresponding subunits from Escherichia coli, thermophilic Bacillus strain PS3, Rhodospirillum rubrum, spinach chloroplasts, and the cyanobacterium Synechococcus strain PCC 6716. The analysis of total RNA by Northern hybridization experiments reveals the presence of transcripts (mRNA) of the genes i, a, and b subunits not found in the isolated enzyme. Analysis of the nucleotide sequence of the atp genes reveals overlap of the structural genes for the i and a subunits and the presence of secondary structures (in the b gene) which could influence the posttranscriptional regulation of the corresponding genes.

Das, A; Ljungdahl, L G

1997-01-01

396

Hemolytic uremic syndrome and Clostridium difficile colitis  

PubMed Central

Hemolytic uremic syndrome (HUS) can be associated with different infectious etiologies, but the relationship between pseudomembranous colitis and HUS was first described in the 1970s in some childhood patients. There is very limited published literature on Clostridium difficile-associated HUS. We report a case of C. difficile-related HUS in an adult patient and provide a review of the literature.

Keshtkar-Jahromi, Maryam; Mohebtash, Mahsa

2012-01-01

397

Transcriptional Regulation of Solventogenesis in Clostridium acetobutylicum  

Microsoft Academic Search

Solvent synthesis in Clostridium acetobutylicum is induced in concert with sporulation to counteract the dangerous effects of produced butyric and acetic acids and to provide the cell with sufficient time to complete endospore formation. Cardinal transcription units for butanol and acetone produc- tion are the sol and adc operons encoding butyr- aldehyde\\/butanol dehydrogenase and coenzyme A transferase as well as

Peter Durre; Michael Bohringer; Stephan Nakotte; Steffen Schaffer; Brigitte Zickner

2002-01-01

398

Clostridium difficile in children: colonisation and disease.  

PubMed

Clostridium difficile is the commonest cause of hospital acquired diarrhoea in adults and is associated with significant mortality and morbidity. The clinical significance of C. difficile in children, however, is less certain. In this article we discuss colonisation and infection and describe C. difficile in childhood in terms of risk factors, epidemiology and management. PMID:21664931

Enoch, David A; Butler, Matthew J; Pai, Sumita; Aliyu, Sani H; Karas, J Andreas

2011-06-12

399

Molecular Size of Clostridium Botulinum Toxins.  

National Technical Information Service (NTIS)

The molecular size of the various types of Clostridium botulinum toxins in spent culture have been estimated. The estimates were based on the rate of sedimentation of the toxin as measured by mouse assay before and after ultracentrifugation of culture. Th...

E. J. Schantz L. Spero

1966-01-01

400

Clostridium botulinum in Cattle and Dairy Products  

Microsoft Academic Search

The use of plastic-wrapped and nonacidified silage as cattle feed has led to an increasing number of botulism outbreaks due to Clostridium botulinum Groups I-III in dairy cattle. The involvement of Groups I and II organisms in cattle botulism has raised concern of human botulism risk associated with the consumption of dairy products. Multiplication of C. botulinum in silage and

Miia Lindström; Jan Myllykoski; Seppo Sivelä; Hannu Korkeala

2010-01-01

401

Nosocomial empyema caused by Clostridium difficile.  

PubMed Central

Pleural infection with Clostridium difficile is extremely rare. A case of nosocomial empyema following chest drain insertion in a 46 year old man is described. The potential of C difficile to cause extra-intestinal infections should be recognised and its isolation from other sites should not be ignored.

Simpson, A J; Das, S S; Tabaqchali, S

1996-01-01

402

JAMA Patient Page: Clostridium Difficile Colitis  

MedlinePLUS

... ways to reduce spread of these types of infection. The March 4, 2009, issue of JAMA contains an article about Clostridium difficile colitis. RISK FACTORS FOR MORE INFORMATION • Centers for Disease Control and Prevention www.cdc.gov • National Institute of ...

403

Clostridium difficile-Associated Diarrhea and Colitis  

Microsoft Academic Search

Objectives: To review and summarize the status of diagnosis, epidemiology, infection control, and treatment of Clostridium difficile-associated disease (CDAD). Diagnosis: A case definition of CDAD should include the presence of symptoms (usually diarrhea) and at least one of the following positive tests: endoscopy revealing pseudomembranes, stool cytotoxicity test for toxin B, stool enzyme immunoassay for toxin A or B, or

Dale N. Gerding; Stuart Johnson; Lance R. Peterson; Maury E. Mulligan; Joseph Silva Jr.

1995-01-01

404

Purification and reconstitution into proteoliposomes of the F1F0 ATP synthase from the obligately anaerobic gram-positive bacterium Clostridium thermoautotrophicum.  

PubMed Central

The proton-translocating F1F0 ATP synthase from Clostridium thermoautotrophicum was solubilized from cholate-washed membranes with Zwittergent 3-14 at 58 degrees C and purified in the presence of octylglucoside by sucrose gradient centrifugation and ion-exchange chromatography on a DEAE-5PW column. The purified enzyme hydrolyzed ATP at a rate of 12.6 micromol min(-1) mg(-1) at 58 degrees C and pH 8.5. It was composed of six different polypeptides with molecular masses of 60, 50, 32, 19, 17, and 8 kDa. These were identified as alpha, beta, gamma, delta, epsilon, and c subunits, respectively, as their N-terminal amino acid sequences matched the deduced N-terminal amino acid sequences of the corresponding genes of the atp operon sequenced from Clostridium thermoaceticum (GenBank accession no. U64318), demonstrating the close similarity of the F1F0 complexes from C. thermoaceticum and C. thermoautotrophicum. Four of these subunits, alpha, beta, gamma, and epsilon, constituted the F1-ATPase purified from the latter bacterium. The delta subunit could not be found in the purified F1 although it was present in the F1F0 complex, indicating that the F0 moiety consisted of the delta and the c subunits and lacked the a and b subunits found in many aerobic bacteria. The c subunit was characterized as N,N'-dicyclohexylcarbodiimide reactive. The F1F0 complex of C. thermoautotrophicum consisting of subunits alpha, beta, gamma, delta, epsilon, and c was reconstituted with phospholipids into proteoliposomes which had ATP-Pi exchange, carbonylcyanide p-trifluoromethoxy-phenylhydrazone-stimulated ATPase, and ATP-dependent proton-pumping activities. Immunoblot analyses of the subunits of ATP synthases from C. thermoautotrophicum, C. thermoaceticum, and Escherichia coli revealed antigenic similarities among the F1 subunits from both clostridia and the beta subunit of F1 from E. coli.

Das, A; Ivey, D M; Ljungdahl, L G

1997-01-01

405

Cloning, developmental regulation and neural localization of rat epsilon-sarcoglycan.  

PubMed

Mutations in the gene for epsilon sarcoglycan (epsilon-SG) are associated with a disorder of the central nervous system, the myoclonus-dystonia syndrome (MDS; DYT11). In contrast, mutations of other sarcoglycan family members lead to limb-girdle muscular dystrophies. To establish the framework for functional studies of epsilon-SG, we cloned rat epsilon-SG cDNA, quantified epsilon-SG mRNA levels in neural and non-neural tissues at different developmental time points with relative quantitative multiplex real-time reverse transcriptase PCR (RT-PCR), and characterized the distribution of epsilon-SG mRNA in brain with in situ hybridization. Rat epsilon-SG cDNA contains an open reading frame (ORF) of 1311 bp that encodes a 437-amino acid (aa) protein with 95.9% and 98.2% identity to human and mouse epsilon-SG amino acid sequences, respectively. Using real-time RT-PCR, epsilon-SG was detected in both neural (cerebellar cortex, striatum, cerebral cortex, thalamus, hippocampus) and non-neural (muscle, liver, kidney, heart) tissues at each developmental time point tested [Embryonic Day 20 (E20), Postnatal Day 1 (P1), P7, P14, P36, 6 months, 1.5 years). Levels of epsilon-SG mRNA were highest at E20 in all tissues. The developmental regulation of epsilon-SG mRNA expression was most striking in muscle with E20 and early postnatal epsilon-SG mRNA levels over 10 times higher than those seen in adult rats. In adult rats, epsilon-SG mRNA levels were several-fold higher in brain, particularly cerebellar cortex, than in muscle. Radioactive in situ hybridization showed that epsilon-SG mRNA was widely distributed in rat brain. Robust hybridization signal was obtained from regions with dense neuronal packing such as the hippocampus, cerebellar molecular layer, and cerebral cortex. Our results suggest that epsilon-SG participates in the development of both neural and non-neural tissues and contributes to neuronal structure in the adult central nervous system. PMID:14625080

Xiao, Jianfeng; LeDoux, Mark S

2003-11-26

406

Complete Genome Sequence of Clostridium clariflavum DSM 19732  

SciTech Connect

Clostridium clariflavum is a Cluster III Clostridium within the family Clostridiaceae isolated from thermophilic anaerobic sludge (Shiratori et al, 2009). This species is of interest because of its similarity to the model cellulolytic organism Clostridium thermocellum and for the ability of environmental isolates to break down cellulose and hemicellulose. Here we describe features of the 4,897,678 bp long genome and its annotation, consisting of 4,131 proteincoding and 98 RNA genes, for the type strain DSM 19732.

Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Davenport, Karen W. [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Bruce, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Han, James [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lynd, Lee R [Thayer School of Engineering at Dartmouth

2012-01-01

407

Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form  

Microsoft Academic Search

During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal ({var_epsilon}-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of

Jarrod V. Crum; Denis M. Strachan

2012-01-01

408

Wall Functions for the kappa-Epsilon Turbulence Model in Generalized Nonorthogonal Curvilinear Coordinates.  

National Technical Information Service (NTIS)

A k-epsilon turbulence model suitable for compressible flow, including the new wall function formulation, has been incorporated into an existing compressible Reynolds-averaged Navier-Stokes code, F3D. The low Reynolds number k-epsilon model of Chien (1982...

D. L. Sondak R. H. Pletcher W. R. Vandalsem

1992-01-01

409

Data Evaluation for 56Co epsilon + beta+ Decay  

SciTech Connect

Recommended values for nuclear and atomic data pertaining to the {var_epsilon} + {beta}{sup +} decay of {sup 56}Co are provided here, followed by comments on evaluation procedures and a summary of all available experimental data. {sup 56}Co is a radionuclide which is potentially very useful for Ge detector efficiency calibration because it is readily produced via the {sup 56}Fe(p,n) reaction, its half-life of 77.24 days is conveniently long, and it provides a number of relatively strong {gamma} rays with energies up to {approx}3500 keV. The transition intensities recommended here for the strongest lines will be included in the forthcoming International Atomic Energy Agency Coordinated Research Programme document ''Update of X- and Gamma-ray Decay Data Standards for Detector Calibration and Other Applications'', and the analysis for all transitions along with relevant atomic data have been provided to the Decay Data Evaluation Project.

Baglin, Coral M.; MacMahon, T. Desmond

2005-02-28

410

Asymptotic analysis of the k-epsilon turbulent boundary layer  

NASA Astrophysics Data System (ADS)

Matched expansions in the limit of infinite Reynolds number are presently used to analyze the representation of attached turbulent boundary-layer flows yielded by the standard form of the k-epsilon model, whose structure is made up of a thin viscous wall-layer, a thick outer 'defect layer' region, and a thin region at the outer edge of the defect layer. Similarity equations governing the outer-layer flow are obtained for equilibrium flow situations, yielding profiles that are not analytic at the outer edge; the asymptotic behavior at the outer edge has a strong influence on the shape of the profiles throughout a significant portion of the entire outer region. The asymptotic results may be the basis of zonal modeling for complex turbulent flow fields.

Bogucz, E. A.

411

High-Pressure Structural Study of Epsilon HNIW (CL-20)  

NASA Astrophysics Data System (ADS)

The structure of epsilon CL-20 at room temperature was investigated using synchrotron angle-dispersive x-ray diffraction experiments and Raman spectroscopy. For x-ray diffraction, the samples were compressed up to 6.3 GPa using a Merrill-Bassett diamond anvil cell (DAC) under both hydrostatic and non-hydrostatic conditions. Pressure - volume data were then fit to the Birch-Murnaghan equation of state to obtain an isothermal equation of state. No phase transition was observed within this pressure range. Raman spectroscopy was performed in the range of 50-1650 cm-1. The samples were compressed non-hydrostatically to 7.1 GPa. Changes in peak positions with increasing pressure were observed. Vibrational spectra were calculated using Hartree-Fock and density functional theory and a comparison was made with the experimental spectrum.

Gump, Jared C.; Wong, Chak P.; Zerilli, Frank J.; Peiris, Suhithi M.

2004-07-01

412

Discovery of the February epsilon Virginids (FEV, IAU #506)  

NASA Astrophysics Data System (ADS)

Combining first week of February CAMS and SonotaCo data resulted in the detection of at least one previously unreported shower. The February epsilon Virginids radiate from R.A. = 201.7° and Dec = +10.4°, with a mean geocentric velocity of 63.0 km/s at solar longitude 315.3°. The mean orbital elements of these meteoroids are q = 0.488 ± 0.021 AU, 1/a = 0.085 ± 0.095 1/AU, e = 0.958 ± 0.046, $i = 138.1° ± 1.3°, ? = 271.32deg; ± 3.7°, and ? = 315.3° ± 0.9°. The shower may originate from comet C/1808 F1 (Pons), if that comet is a Halley-type comet.

Steakley, Kathryn; Jenniskens, Peter

2013-08-01

413

Random errors for a nonlocal Epsilon Negative medium  

NASA Astrophysics Data System (ADS)

A medium embedded with finite length perfectly conducting needles can be taken as a nonlocal Epsilon Negative medium. The medium is nonlocal due to the presence of spatial dispersion. A theoretical analysis for effects of random errors in positioning and orientation of finite length needles upon the ensemble averaged nonlocal effective permittivity is presented. It is studied that an increase in positioning and orientation errors of needles can reduce and even eliminate the negative bandwidth. The word negative bandwidth is used to represent the range of frequency for which the real part of the effective permittivity is negative. Also these errors widen the bandwidth of an absorption peak associated with an imaginary part of the effective permittivity.

Awan, Z. A.; Rizvi, A. A.

2013-05-01

414

The International epsilon Aurigae Campaign 2009 Photometry Report  

NASA Astrophysics Data System (ADS)

An International Campaign and Web site were started in May of 2006 for the 2009-2011 eclipse of the mysterious star system epsilon Aurigae. Photometric and spectroscopic observations of the eclipse were coordinated and reported. The eclipse started in the summer of 2009 and lasted until the spring of 2011. During the campaign twenty-four newsletters were published on the web site and made available free as .pdf files to read and download. Twenty-six observers from fourteen different countries submitted photometric data in the UBVRI bands. Over 3,600 high-quality photometric observations were submitted with nearly 2,000 observations in just the V band. This paper discusses the Campaign and reports the results.

Hopkins, J. L.

2012-07-01

415

RhoA activates purified phospholipase C-epsilon by a guanine nucleotide-dependent mechanism.  

PubMed

Phospholipase C-epsilon (PLC-epsilon) is a recently identified PLC isoform activated by subunits of heterotrimeric G proteins (Galpha(12), Galpha(13), and Gbetagamma) as well as by the low molecular weight GTPases, Rho and Ras. To define the enzymatic activity and substrate specificity of PLC-epsilon as well as its potential direct activation by Rho family GTPases, a major fragment of PLC-epsilon encompassing the catalytic core (EF-hand repeats through the tandem Ras-associating domains; approximately 118 kDa) was purified to near homogeneity and assayed after reconstitution under various conditions. Similar to the enzymatic profiles of previously purified PLC-beta isozymes, the purified fragment of PLC-epsilon maximally hydrolyzed phosphatidylinositol 4-phosphate at a rate of approximately 10 mumol/mg of protein/min, exhibited phospholipase activity dependent on the concentration of free calcium, and favored phosphatidylinositol 4,5-bisphosphate as substrate relative to other phosphoinositides. Furthermore, in mixed detergent phospholipid micelles, RhoA stimulated the phospholipase activity of the PLC-epsilon fragment in both a concentration-dependent and guanosine 5'-O-(3-thiotriphosphate)-dependent manner. This activation was abolished by the deletion of a unique approximately 65 amino acid-insert within the catalytic core of PLC-epsilon. Although Rac1 activated purified PLC-beta2ina guanine nucleotide-dependent manner, Rac1 failed to promote guanine nucleotide-dependent activation of purified PLC-epsilon. These results indicate that PLC-epsilon is a direct downstream effector for RhoA and that RhoA-dependent activation of PLC-epsilon depends on a unique insert within the catalytic core of the phospholipase. PMID:15322077

Seifert, Jason P; Wing, Michele R; Snyder, Jason T; Gershburg, Svetlana; Sondek, John; Harden, T Kendall

2004-08-18

416

Differential regulation of alternative 3{prime} splicing of {epsilon} messenger RNA variants  

SciTech Connect

Alternative 3{prime} splicing of the one active human {epsilon} heavy chain gene results in variants of {epsilon} mRNA encoding distinct IgE proteins. The same relative amounts of these {epsilon} mRNA variants were produced by non-atopic donor B cells when driven in a variety of T-dependent or T-independent systems. The most abundant variants were those for classic secreted {epsilon} and a novel secreted form (CH4-M2{double_prime}). In contrast, cells from subjects with high levels of serum IgE secondary to parasitic infection or atopy spontaneously produced higher relative levels of the CH4-M2{prime} {epsilon} mRNA variant, lower relative amounts of both the membrane and CH4-M2{double_prime} secreted variants, and very low levels of the CH4{prime}-CH5 variant. The existence of and corresponding changes in levels of the CH4-M2{prime}-enclosed secreted protein were demonstrated. IL-10 induced this same differential expression of {epsilon} splice variants in vitro when used to costimulate IL-4 plus CD40-driven B cells and could differentially enhance the production of CH4-M2{prime} protein by established IgE-secreting cell lines. Inhibition of IgE by cross-linking the low affinity IgE receptor (CD23) decreased the levels of {epsilon} mRNA and resulted in a distinct pattern of {epsilon} mRNA characterized by a dramatic decrease in CH4-M2{prime} splice variant. IL-6, IL-2, or IFN-{gamma} did not change the {epsilon} mRNA pattern. Overall, the absolute and relative amounts of the different {epsilon} mRNA splice variants produced appear to be controlled in a differentiation-related fashion.

Diaz-Sanchez, D.; Zhang, K.; Saxon, A. [Univ. of California School of Medicine, Los Angeles, CA (United States)] [and others

1995-08-15

417

A case if infant botulism due to neurotoxigenic Clostridium butyricum type E associated with Clostridium difficile colitis.  

PubMed

Reported here is the sixth case of intestinal toxemia botulism caused by Clostridium butyricum type E in Italy since 1984. In this case, the patient was concomitantly affected with colitis due to Clostridium difficile toxin. A review of previously reported cases revealed that some of these patients may also have had intestinal toxemia botulism associated with Clostridium difficile colitis, based on the reported symptoms. Given that this association has been shown to exist not only in Italy but also in the USA, it is recommended that individuals with intestinal botulism and symptoms of colitis undergo testing for Clostridium difficile and its toxins in fecal samples. PMID:12479171

Fenicia, L; Da Dalt, L; Anniballi, F; Franciosa, G; Zanconato, S; Aureli, P

2002-10-01

418

42 CFR 493.911 - Bacteriology.  

Code of Federal Regulations, 2010 CFR

...group Clostridium perfringens Peptostreptococcus anaerobius Enterobacteriaceae Citrobacter freundii Enterobacter aerogenes Escherichia coli Klebsiella pneumoniae Proteus mirabilis Salmonella typhimurium Serratia...

2009-10-01

419

Cellulose fermentation by a coculture of a mesophilic cellulolytic Clostridium and Clostridium acetobutylicum  

SciTech Connect

A coculture of a mesophilic cellulolytic Clostridium with Clostridium acetobutylicum can yield a direct conversion of cellulose into chemicals. In 13 days 30 g/l Solka Floc is degraded and fermented into 14 g/l butyric acid, 4 g/l acetic acid, 3 g/l ethanol, and 1 g/l butanol. A four times higher rate of cellulose hydrolysis than in pure culture of the cellulolytic Clostridium is thus obtained. Fed-batch fermentations of C. acetobutylicum at different glucose feeding rate show that solvents are only produced at a sufficient high rate of glucose supply to the medium. Acids are thus the main products of the coculture because of the limited rate of cellulolysis by the mesophilic strain. 7 references, 5 figures.

Fond, O.; Petitdemange, E.; Petitdemange, H.; Engasser, J.M.

1983-01-01

420

Does my patient have Clostridium difficile infection?  

PubMed

Clostridium difficile infection (CDI) seems to be changing-with increasing virulence and incidence, more resistance to metronidazole, and worse outcomes. Accurate diagnosis is critical, but 3 common misconceptions lead to misdiagnosis: Clostridium difficile infection is a possibility when the patient has fewer than 3 loose stools per day; the glutamate dehydrogenase test for CDI is sensitive and thus is a good initial test; and repeating an insensitive laboratory test for CDI is useful. These misconceptions can lead to missed diagnoses (for example, when tests with low sensitivity are used) and to false diagnoses (for example, when tests are done in patients who are unlikely to have CDI because they have minimal diarrhea or negative results on recent tests). Diagnoses of CDI will be more accurate if clinicians use tests with a higher sensitivity, reduce the frequency of testing for a single episode of diarrhea, and give more attention to key elements of the patient's history. PMID:19652187

Peterson, Lance R; Robicsek, Ari

2009-08-01