| botulism in the united states: a clinical and epidemiologic review. | botulism is caused by a neurotoxin produced from the anaerobic, spore-forming bacterium clostridium botulinum. botulism in humans is usually caused by toxin types a, b, and e. since 1973, a median of 24 cases of foodborne botulism, 3 cases of wound botulism, and 71 cases of infant botulism have been reported annually to the centers for disease control and prevention (cdc). new vehicles for transmission have emerged in recent decades, and wound botulism associated with black tar heroin has increa ... | 1998 | 9696731 |
| lysophosphatidic acid stimulates actomyosin contraction in astrocytes. | lysophosphatidic acid (lpa) is an extracellular signaling molecule that can enter the central nervous system following injury or diseases that disrupt the blood-brain-barrier. using a combination of time-lapse microscopy, immunocytochemistry, and biochemical techniques, we demonstrate that lpa stimulates profound changes in astrocyte morphology that are due to effects on the actomyosin cytoskeleton. flat astrocytes in primary culture display prominent actin stress fibers. treatment with the myos ... | 1998 | 9698162 |
| thrombin inactivates myosin light chain phosphatase via rho and its target rho kinase in human endothelial cells. | the role of rho gtpase and its downstream targets rho kinase and myosin light chain phosphatase in thrombin-induced endothelial cell contraction was investigated. the specific rho inactivator c3-transferase from clostridium botulinum as well as microinjection of the isolated rho-binding domain of rho kinase or active myosin light chain phosphatase abolished thrombin-stimulated endothelial cell contraction. conversely, microinjection of constitutively active v14rho, constitutively active catalyti ... | 1998 | 9705325 |
| binding and transcytosis of botulinum neurotoxin by polarized human colon carcinoma cells. | t-84 and caco-2 human colon carcinoma cells and madin-darby canine kidney (mdck) cells were used to study binding and transcytosis of iodinated clostridium botulinum neurotoxin serotypes a, b, and c, as well as tetanus toxin. specific binding and transcytosis were demonstrated for serotypes a and b in intestinal cells. using serotype a as an example, the rate of transcytosis by t-84 cells was determined in both apical to basolateral (11.34 fmol/h/cm2) as well as basolateral to apical (8.98 fmol/ ... | 1998 | 9705335 |
| growth and toxin production by clostridium botulinum on sliced raw potatoes in a modified atmosphere with and without sulfite. | the ability of clostridium botulinum type a or b spores to grow and produce toxin on fresh raw potatoes in a modified atmosphere with or without sulfite was investigated at 22 degrees c. fresh, peeled, sliced potatoes, untreated or dipped for 2 min into 0.7% sulfite solution and drained, were surface-inoculated at several concentration levels with a mixture of c. botulinum spores, either type a or b. they were placed in a modified atmosphere (30% n/70% co2) within oxygen-impermeable bags (200 g/ ... | 1998 | 9708268 |
| indicative and pathogenic microbiological quality of aquacultured finfish grown in different production systems. | the nature and number of indicator and pathogenic microbes in fish reared using recirculating and nonrecirculating water systems were compared. for each system, 20 samples of rainbow trout (oncorhynchus mykiss), tilapia (oreochromis spp.), hybrid striped bass (morone saxatilis x m. chrysops), and pacu (piaractus mesopotamicus) were randomly selected and gutted, and microbial analyses were performed using aoac procedures. five fish were subsampled and analyzed for indicative microbial quality wit ... | 1998 | 9708283 |
| the incidence of listeria spp., salmonella spp., and clostridium botulinum in smoked fish and shellfish. | the frequency of occurrence of listeria spp., salmonella spp., and clostridium botulinum is samples of smoked finfish and smoked shellfish was analyzed over a 5-year period. listeria monocytogenes were isolated from 14% of 1,080 samples. for those samples where the smoke process was known, the incidence of l. monocytogenes was higher in cold-smoked than hot-smoked products (51 of 240 cold-smoked compared to 19 of 215 hot-smoked products). listeria species other than l. monocytogenes were also de ... | 1998 | 9708303 |
| growth and toxin production by clostridium botulinum on inoculated fresh-cut packaged vegetables. | to determine the safety of fresh-cut vegetables packaged in modified atmosphere, challenge studies using both nonproteolytic and proteolytic strains of clostridium botulinum were performed with a variety of fresh-cut packaged salads and vegetables stored at different temperatures. when vegetables were inoculated with spores of c. botulinum and incubated in low-o2 atmospheres, spore germination and growth and toxin production were observed. botulinum toxin was produced by proteolytic types a and ... | 1998 | 9708304 |
| microbial stability of mango (mangifera indica l.) juice preserved by combined application of mild heat and extracts of two tropical spices. | the microbial stability of mango (mangifera indica l.) juice (ph 4.9) supplemented with extracts of ginger (zingiber officinale) and nutmeg (myristica fragrans) was investigated during 3 months of ambient-temperature storage. heating at 55 degrees c for 15 min markedly reduced the levels of non-spore-forming bacteria and produced a product with acceptable taste. supplementing mango juice with an agueous extract of ginger (15%, vol/vol) or nutmeg (20%, vol/vol) inhibited the growth of challenge m ... | 1998 | 9709257 |
| ganglioside gt1b as a complementary receptor component for clostridium botulinum neurotoxins. | clostridium botulinum type b neurotoxin (bont/b) recognizes a complex of synaptotagmin ii and ganglioside gt1b or gd1a as the high-affinity toxin binding site. recombinant deletion mutants of synaptotagmin ii allowed us to demonstrate that the n-terminal domain including the transmembrane region retains bont/b binding activity while the c-terminal domain is not involved in constituting the bont/b receptor. bont/b binding to reconstituted lipid vesicles containing synaptotagmin ii and ganglioside ... | 1998 | 9712688 |
| camp-induced morphological changes are counteracted by the activated rhoa small gtpase and the rho kinase rokalpha. | dramatic transient changes resulting in a stellate morphology are induced in many cell types on treatment with agents that enhance intracellular camp levels. thrombin fully protects cells from this inductive effect of camp through the thrombin receptor. the protective effect of thrombin was shown to be rho-dependent. clostridium botulinum c3 exoenzyme, which inactivates rhoa functions, abolished the ability of thrombin to protect cells from responding to increased camp levels. a constitutively a ... | 1998 | 9712882 |
| investigation of the ability of proteolytic clostridium botulinum to multiply and produce toxin in fresh italian pasta. | the ability of proteolytic clostridium botulinum (types a, b, and f) to produce toxin in filled fresh italian pasta (tortelli) packed under a modified atmosphere was investigated. four types of tortelli (filled with artichoke, meat, ricotta-spinach, or salmon) were inoculated with a suspension of heat-shocked spores to give an initial concentration of approximately 10(3) spores per piece. samples were incubated at both 12 and 20 degrees c for up to 50 days and examined at selected time intervals ... | 1998 | 9713759 |
| the detection of a deletion in the type b neurotoxin gene of clostridium botulinum a(b) strains by a two-step pcr. | differences between the type b neurotoxin gene sequence of clostridium botulinum type a(b) and cl. botulinum type b, including a six nucleotide deletion, were recently proposed as a cause of the lack of expression of this gene in the type a toxigenic strains. a polymerase chain reaction (pcr) based on two sets of primers was designed to investigate the absence of the 6-nucleotide sequence in the apparently unexpressed type b toxin gene of 42 strains of cl. botulinum type a(b). thirty-five strain ... | 1998 | 9717316 |
| covalent structure of botulinum neurotoxin type b; location of sulfhydryl groups and disulfide bridge and identification of c-termini of light and heavy chains. | botulinum neurotoxin (nt) serotype b, produced by clostridium botulinum (proteolytic strain), is a approximately 150-kda single-chain polypeptide of 1291 amino acids, of which 10 are cys residues [whelan et al. (1992), appl. environ. microbiol. 58, 2345-2354] the posttranslational modifications of the gene product were found to consist of excision of only the initiating met residue, limited proteolysis (nicking) of the 1290-residue-long protein between lys 440 and ala 441, and formation of at le ... | 1998 | 9717738 |
| regulation of the actin cytoskeleton by thrombin in human endothelial cells: role of rho proteins in endothelial barrier function. | endothelial barrier function is regulated at the cellular level by cytoskeletal-dependent anchoring and retracting forces. in the present study we have examined the signal transduction pathways underlying agonist-stimulated reorganization of the actin cytoskeleton in human umbilical vein endothelial cells. receptor activation by thrombin, or the thrombin receptor (proteinase-activated receptor 1) agonist peptide, leads to an early increase in stress fiber formation followed by cortical actin acc ... | 1998 | 9725917 |
| post-transcriptional regulation of endothelial nitric oxide synthase mrna stability by rho gtpase. | the mechanism by which 3-hydroxy-3-methylglutaryl (hmg)-coa reductase inhibitors increase endothelial nitric oxide synthase (enos) expression is unknown. to determine whether changes in isoprenoid synthesis affects enos expression, human endothelial cells were treated with the hmg-coa reductase inhibitor, mevastatin (1-10 microm), in the presence of l-mevalonate (200 microm), geranylgeranylpyrophosphate (ggpp, 1-10 microm), farnesylpyrophosphate (fpp, 5-10 microm), or low density lipoprotein (ld ... | 1998 | 9727051 |
| analysis of the botulinum neurotoxin type f gene clusters in proteolytic and nonproteolytic clostridium botulinum and clostridium barati. | comparison of genes encoding type f botulinum neurotoxin progenitor complex in strains of proteolytic clostridium botulinum strain langeland, nonproteolytic clostridium botulinum strain 202f, and clostridium barati strain atcc 43256 reveals an identical organization of genes encoding a protein of molecular mass of approx. 47 kda (p-47), nontoxic-nonhemagglutinin (ntnh) and botulinum toxin (bont). although homology between the protein components of the complexes encoded by these different species ... | 1998 | 9732534 |
| a novel bacteriocin with a ygngv motif from vegetable-associated enterococcus mundtii: full characterization and interaction with target organisms. | a novel broad-spectrum antimicrobial peptide produced by vegetable-associated enterococcus mundtii was purified and characterized, and designated mundticin. to our knowledge, this is the first report on bacteriocin production by this organism. the elucidation of the full primary amino acid sequence of mundticin (kyygngvscnkkgcsvdwgkaigiignnsaanlatggaagwsk) revealed that this antimicrobial peptide belongs to the class iia bacteriocins of lactic acid bacteria which share a highly conserved n-termi ... | 1998 | 9733915 |
| are tyrosine phosphorylation of p125(fak) and paxillin or the small gtp binding protein, rho, needed for cck-stimulated pancreatic amylase secretion? | studies of a possible role of tyrosine phosphorylation in the secretory process in rat pancreatic acinar cells provide conflicting conclusions. recent studies show that tyrosine phosphorylation of the focal adhesion kinase, p125fak and the cytoskeletal protein, paxillin, may mediate a number of cellular changes and this phosphorylation is dependent on the activation of the small gtp binding protein, p21rho (rho). in this work we have investigated the role of tyrosine phosphorylation of each of t ... | 1998 | 9739170 |
| prospects for chemiluminescent and bioluminescent immunoassay and nucleic acid assays in food testing and the pharmaceutical industry. | the sensitivity, speed and convenience of chemiluminescent (cl) and bioluminescent (bl) immunoassays and probe assays have led to a diverse range of applications for these technologies, mainly in the clinical laboratory. these methods are now being explored by the food and pharmaceutical industries. demanding detection limits and the complexity of sample preparation for food and pharmaceutical analyses present daunting challenges for the analyst. immunoassay and nucleic acid amplification techno ... | 1998 | 9743442 |
| characterization of clostridium botulinum type b neurotoxin associated with infant botulism in japan. | the neurotoxin of strain 111 (111/nt) associated with type b infant botulism showed antigenic and biological properties different from that (okra/nt) produced by a food-borne botulism-related strain, okra. the specific toxicity of 111/nt was found to be about 10 times lower than that of okra/nt. the monoclonal antibodies recognizing the light chain cross-reacted with both neurotoxins, whereas most of the antibodies recognizing the carboxyl-terminal half of the heavy chain of okra/nt did not reac ... | 1998 | 9746583 |
| a review of analytical methods for the detection of bacterial toxins. | | 1998 | 9750366 |
| role of g proteins in agonist-induced ca2+ sensitization of tracheal smooth muscle. | increased sensitivity to intracellular ca2+ concentration ([ca2+]) is an important mechanism for agonist-induced contraction of airway smooth muscle, but the signal transduction pathways involved are uncertain. we studied ca2+ sensitization with acetylcholine (ach) and endothelin (et)-1 in porcine tracheal smooth muscle by measuring contractions at a constant [ca2+] in strips permeabilized with alpha-toxin or beta-escin. the peptide inhibitor g protein antagonist 2a (gp ant-2a), which has select ... | 1998 | 9755107 |
| activation of cyclin-dependent kinase 2 (cdk2) in growth-stimulated rat astrocytes. geranylgeranylated rho small gtpase(s) are essential for the induction of cyclin e gene expression. | the role of the mevalonate cascade in the control of cell cycle progression in astrocytes has been investigated. serum stimulation of rat astrocytes in primary culture induces the expression of cyclin e followed by the activation of cyclin-dependent kinase 2 (cdk2) during g1/s transition. the expression of p27, cyclin d1, and the activities of cdk4 and cdk-activating kinase (cak), composed of cdk7 and cyclin h, were not affected. serum did, however, stimulate the expression of 3-hydroxy-3-methyl ... | 1998 | 9756921 |
| type e botulism associated with vacuum-packaged hot-smoked whitefish. | on january 16, 1997 two germans got botulism after eating hot-smoked canadian whitefish produced in finland. the serum sample of one of the patients contained 6 mld/ml of botulinum toxin. the type of toxin was identified as e by the toxin neutralization test and the botulinum neurotoxin type e (bont/e) gene was also amplified from the serum by polymerase chain reaction (pcr), but c. botulinum could not be isolated from the positive serum sample. the remains of the hot-smoked whitefish eaten by t ... | 1998 | 9761332 |
| adenosine diphosphate (adp)-ribosylation of the guanosine triphosphatase (gtpase) rho in resting peripheral blood human t lymphocytes results in pseudopodial extension and the inhibition of t cell activation. | scrape loading clostridium botulinum c3 exoenzyme into primary peripheral blood human t lymphocytes (pb t cells) efficiently adenosine diphosphate (adp)-ribosylates and thus inactivates the guanosine triphosphatase (gtpase) rho. basal adhesion of pb t cells to the beta1 integrin substrate fibronectin (fn) was not inhibited by inactivation of rho, nor was upregulation of adhesion using phorbol myristate acetate (pma; 10 ng/ml) or mn++ (1 mm) affected. whereas untreated pb t cells adherent to fn r ... | 1998 | 9763600 |
| microbiological quality and the inability of proteolytic clostridium botulinum to produce toxin in film-packaged fresh-cut cabbage and lettuce. | the production of toxin by a 10-strain mixture of proteolytic clostridium botulinum in fresh produce packaged in polyethylene films having high (7,000 cc/m2/24 h; hotr) and low (3,000 cc/m2/24 h; lotr) relative oxygen permeability was determined. shredded cabbage and lettuce inoculated with approximately 10(2) spores/g were placed in bags composed of the two films (1.4 kg/bag), and the bags were then vacuum sealed. produce was stored at 4, 13, and 21 degrees c for up to 21 (cabbage) or 28 (lettu ... | 1998 | 9766066 |
| conservative prediction of time to clostridium botulinum toxin formation for use with time-temperature indicators to ensure the safety of foods. | integrating-type time-temperature indicators (ttis) may be utilized to warn food processors and consumers about storage conditions that may have rendered a food potentially hazardous. as an example of how integrated ttis could be manufactured to emulate an infinite set of time-temperature situations, a set of conditions which have supported c. botulinum growth and toxin production was compiled. the time-temperature curve representing conservative times required for toxin formation was constructe ... | 1998 | 9766067 |
| botr/a is a positive regulator of botulinum neurotoxin and associated non-toxin protein genes in clostridium botulinum a. | the genes of the botulinum neurotoxin a (bont) complex are clustered in a locus consisting of two divergent polycistronic operons, one containing the non-toxic, non-haemagglutinin (ntnh) component and bonta genes, the other containing the haemagglutinin (ha) component genes. the two operons are separated by a gene (botr/a, previously called orf21) encoding a 21 kda protein. a recombinant clostridium botulinum a strain that overexpresses botr/a was constructed by electroporating strain 62 with th ... | 1998 | 9767569 |
| characterization of the genes encoding the botulinum neurotoxin complex in a strain of clostridium botulinum producing type b and f neurotoxins. | the organization of the clusters of genes encoding proteins of the botulinum neurotoxin (bont) progenitor complex was elucidated in a strain of clostridium botulinum producing type b and f neurotoxins. with pcr and sequencing strategies, the type b bont-gene cluster was found to be composed of genes encoding bont/b, nontoxic nonhemagglutinin component (ntnh), p-21, and the hemagglutinins ha-33, ha-17, and ha-70, whereas the type f bont-gene cluster has genes encoding bont/f, ntnh, p-47, and p-21 ... | 1998 | 9767710 |
| isolation of synaptotagmin as a receptor for types a and e botulinum neurotoxin and analysis of their comparative binding using a new microtiter plate assay. | clostridium botulinum neurotoxin acts on nerve endings to block acetylcholine release. binding of the neurotoxin to a membrane receptor through its heavy chain is the first essential step in its mode of toxin action. type e botulinum neurotoxin (bont/e) or type a botulinum neurotoxin (bont/a) receptor was purified from rat brain synaptosomes employing a neurotoxin affinity column chromatography. the protein fraction eluted from the affinity column with 0.5 m nacl contained a 57 kda protein as a ... | 1998 | 9783260 |
| hemagglutinin binding mediated protection of botulinum neurotoxin from proteolysis. | type a clostridium botulinum, the causative agent of the food poisoning botulism disease, secretes botulinum neurotoxins along with seven neurotoxin associated proteins (naps). the function of naps has been shown to protect the neurotoxin from acidity, heat, and proteolytic attack in the environmental and gastrointestinal tract during the toxicogenesis of the botulism disease. one of the naps, purified from type a botulinum neurotoxin complex, showed hemagglutination activity. a direct interacti ... | 1998 | 9783262 |
| role of rho proteins in agonist regulation of phospholipase d in hl-60 cells. | rho family gtp-binding proteins have been demonstrated to play a role in the regulation of phospholipase d (pld) activity. in the present study, we examined the role of rho proteins in pld activation in differentiated hl-60 cells using c3 exoenzyme from clostridium botulinum, which adp-ribosylates and inactivates rho proteins. introduction of c3 exoenzyme into differentiated hl-60 cells by electroporation resulted in complete inhibition of pld activity stimulated by formyl methionine-leucine-phe ... | 1998 | 9784628 |
| constitutively active galpha12, galpha13, and galphaq induce rho-dependent neurite retraction through different signaling pathways. | in neuronal cells, activation of a certain heterotrimeric g protein-coupled receptor causes neurite retraction and cell rounding via the small gtpase rho. however, the specific heterotrimeric g proteins that mediate rho-dependent neurite retraction and cell rounding have not yet been identified. here we investigated the effects of expression of constitutively active galpha subunits on the morphology of differentiated pc12 cells. expression of gtpase-deficient galpha12, galpha13, and galphaq, but ... | 1998 | 9786865 |
| characterization of the catalytic site of the adp-ribosyltransferase clostridium botulinum c2 toxin by site-directed mutagenesis. | the actin adp-ribosylating clostridium botulinum c2 toxin is a binary toxin composed of the binding component c2ii and the enzyme component c2i. c2i adp-ribosylates g-actin at arginine 177, resulting in the depolymerization of the actin cytoskeleton. here, we studied the structure-function relationship of c2i by site-directed mutagenesis. exchange of glu389 to glutamine caused the complete loss of adp-ribosyltransferase and nad-glycohydrolase activities of c2i. in contrast, exchange of glu387 to ... | 1998 | 9792657 |
| identifying the principal protective antigenic determinants of type a botulinum neurotoxin. | the neurotoxins from clostridium botulinum (bont serotypes a-g) exert their lethal effect by preventing the release of acetylcholine at the neuromuscular junction. as with tetanus toxin, immunization with a non-toxic fragment, the 50 kda c-terminal portion of bont/a (hc; residues 861-1296), protects mice against lethal challenges with the intact toxin. to locate the neutralizing epitopes, several protective monoclonal antibodies (mabs) against bont/a-hc were isolated and cloned. specific binding ... | 1998 | 9795391 |
| the role of clostridium botulinum: a neurotoxin in clinical dermatology. | | 1998 | 9795588 |
| prevalence of clostridium botulinum in finnish trout farms: pulsed-field gel electrophoresis typing reveals extensive genetic diversity among type e isolates. | the distribution of clostridium botulinum serotypes a, b, e, and f in finnish trout farms was examined. a total of 333 samples were tested with a neurotoxin-specific pcr assay. c. botulinum type e was found in 68% of the farm sediment samples, in 15% of the fish intestinal samples, and in 5% of the fish skin samples. no other serotypes were found. the spore counts determined by the most-probable-number method were considerably higher for the sediments than for the fish intestines and skin; the a ... | 1998 | 9797260 |
| analysis of the influence of environmental parameters on clostridium botulinum time-to-toxicity by using three modeling approaches. | this study used the technique of waiting time modeling to analyze the combined effects of temperature, ph, carbohydrate, protein, and lipid on the time-to-toxicity of clostridium botulinum 56a. waiting time models can be used whenever the time to the occurrence of some event is the variable of interest. in the case of the time-to-toxicity data, the variable is the time from the beginning of an experiment until a tube is identified as positive. the statistical analysis used the sas procedure life ... | 1998 | 9797300 |
| molecular composition of the 16s toxin produced by a clostridium botulinum type d strain, 1873. | the 16s toxin was purified from a clostridium botulinum type d strain 1873 (d-1873). furthermore, the entire nucleotide sequences of the genes coding for the 16s toxin were determined. it became clear that the purified d-1873 16s toxin consists of neurotoxin, nontoxic nonhemagglutinin (ntnh), and hemagglutinin (ha), and that ha consists of four subcomponents, ha1, ha2, ha3a, and ha3b, the same as type d strain cb16 (d-cb16) 16s toxin. the nucleotide sequences of the nontoxic components of these ... | 1998 | 9802560 |
| evidence of zeta protein kinase c involvement in polymorphonuclear neutrophil integrin-dependent adhesion and chemotaxis. | classical chemoattractants and chemokines trigger integrin-dependent adhesion of blood leukocytes to vascular endothelium and also direct subsequent extravasation and migration into tissues. in studies of human polymorphonuclear neutrophil responses to formyl peptides and to interleukin 8, we show evidence of involvement of the atypical zeta protein kinase c in the signaling pathway leading to chemoattractant-triggered actin assembly, integrin-dependent adhesion, and chemotaxis. selective inhibi ... | 1998 | 9804792 |
| adp-ribosylation factor proteins mediate agonist-induced activation of phospholipase d. | the role of small g proteins of the adp-ribosylation factor (arf) and rho families on the activation of phospholipase d (pld) by platelet-derived growth factor (pdgf) and phorbol esters (pma) has been investigated. the activation of pld by pdgf and pma was blocked by brefeldin a (bfa), an inhibitor of arf activation, but not by clostridium botulinum c3 exotoxin, an inhibitor of the activity of rho. pdgf and pma, in the presence of gtpgammas, promoted the association of arf and rhoa with cell mem ... | 1998 | 9804862 |
| conjugative transfer of the escherichia coli-clostridium perfringens shuttle vector pjir1457 to clostridium botulinum type a strains. | an rp4-orit shuttle vector pjir1457 originally developed for clostridium perfringens was successfully transferred by conjugation from escherichia coli to clostridium botulinum type a strains and to a nontoxigenic c. botulinum type a-transposon tn916 mutant strain lacking the entire toxin gene cluster. the light chain (lc) of botulinum toxin was highly expressed in the toxin deletion mutant strain from a pjir1457 construct containing the recombinant botulinal gene for lc. this shuttle vector syst ... | 1998 | 9806860 |
| [botulism. summary based on six cases]. | botulism is a rare neuroparalytic disease caused by neurotoxins of clostridium species. in hungary it most commonly occurs as a foodborne illness with ocular and bulbar paralysis, muscle weakness and gastrointestinal symptoms. six cases of botulism were observed by the authors, first in 1993 five members of a family, then in 1997 a patient with sporadic illness. the diagnosis was confirmed by toxin tests in addition to the symptoms and food history. recognition of the epidemiologic associations ... | 1998 | 9810163 |
| a pcr survey of psychrotrophic clostridium botulinum-like isolates for the presence of bont genes. | isolates (259) of psychrotrophic clostridium spp. associated with either blown pack spoilage (five isolates) or slaughter stock (254 isolates) were screened for the presence of botulinum neurotoxin (bont) genes using degenerate pcr primers capable of amplifying a, b, e, f and g bont genes. no bont gene amplification products were detected using dna templates from the 259 psychrotrophic isolates, including 249 isolates that showed the same 16s rrna gene restriction fragment length polymorphism (r ... | 1998 | 9812399 |
| the production and quality of tomato concentrates. | the standards and specifications for the quality and composition of tomato concentrates are reviewed. the main quality parameters of tomato puree and paste are color, consistency and flavor. overall, there is an absence of standardization of methods and instruments to define quality. while color can now be measured objectively, there are currently no standard color requirements for tomato concentrates. rheological measurements on both tomato juice and concentrates are reviewed; the power law fin ... | 1998 | 9813734 |
| preliminary evaluation of a simple in vitro test for the diagnosis of type c botulism in wild birds. | an enzyme-linked immunosorbent assay (elisa) was developed for the detection of type c botulinum toxin (clostridium botulinum) in wild birds. this simple, antigen-capture elisa utilizes polystyrene immunosticks as the solid substrate, chicken antitoxin (igy) as the coating antibody, rabbit antitoxin as the primary antibody, and peroxidase-labeled goat-anti-rabbit as the secondary antibody. to evaluate the immunostick elisa as a diagnostic test for avian botulism, known concentrations of toxin we ... | 1998 | 9813844 |
| the inhibition of clostridium botulinum type c by other bacteria in wetland sediments. | bacteria with inhibitory activity against clostridium botulinum type c were isolated from 32% of sediment samples (n = 1600) collected from 10 marshes in a northern california wetland over a 12 mo period. aerobic and anaerobic bacteria with inhibitory activity were isolated from 12% and 23% of the samples, respectively. bacteria with inhibitory activity were isolated from all 10 study sites and throughout the year. this study demonstrates that bacteria with inhibitory activity against c. botulin ... | 1998 | 9813858 |
| pasteurella multocida toxin increases endothelial permeability via rho kinase and myosin light chain phosphatase. | pasteurella multocida toxin (pmt) has been shown to induce actin reorganization through activation of the gtpase rho. here we investigated the involvement of the rho target proteins rho kinase and myosin light chain (mlc) phosphatase in the pmt-induced increase in endothelial permeability and the underlying actin reorganization of endothelial cells. stimulation of endothelial layers with pmt enhanced transendothelial permeability > 10-fold, and this was abolished by pretreatment with the specifi ... | 1998 | 9820544 |
| tetr is a positive regulator of the tetanus toxin gene in clostridium tetani and is homologous to botr. | the tetr gene immediately upstream from the tetanus toxin (tetx) gene was characterized. it encodes a 21,562-da protein which is related (50 to 65% identity) to the equivalent genes (botr) in clostridium botulinum. tetr has the feature of a dna binding protein with a basic pi (9.53). it contains a helix-turn-helix motif and shows 29% identity with other putative regulatory genes in clostridium, i.e., uvia from c. perfringens and txer from c. difficile. we report for the first time the transforma ... | 1998 | 9826344 |
| botulinum toxin: chemistry, pharmacology, toxicity, and immunology. | the seven serotypes of botulinum toxin (btx) produced by clostridium botulinum exert their paralytic effect by inhibiting acetylcholine release at the neuromuscular junction. each of these zinc endopeptidases cleaves one or more proteins involved in vesicle transport and membrane fusion. the extent of paralysis depends on both doses and volume; the duration of paralysis is further dependent on the serotype employed. restoration of neuromuscular function follows axon terminal sprouting. the two m ... | 1997 | 9826987 |
| oculoplastic experience with the cosmetic use of botulinum a exotoxin. | botulinum toxin is a neuromuscular blocking agent produced by the bacterium clostridium botulinum. it has been used as a therapeutic agent in ophthalmology for over 18 years. | 1998 | 9834740 |
| complications of botulinum a exotoxin for hyperfunctional lines. | clostridium botulinum type a exotoxin is one of the recent advances for treatment of the aging face. due to the sudden and exponential surge in popularity, there is little precise consensus regarding its safety and efficacy. many of the reported complications associated with its aesthetic use are few and anecdotal. as we gain more experience and long-term follow-up with this procedure, complications and their treatment can be better documented. as most of the salutary effects of botulinum toxin ... | 1998 | 9834747 |
| genetic characterization and heterologous expression of brochocin-c, an antibotulinal, two-peptide bacteriocin produced by brochothrix campestris atcc 43754. | brochocin-c, produced by brochothrix campestris atcc 43754, is active against many strains of the closely related meat spoilage organism brochothrix thermosphacta and a wide range of other gram-positive bacteria, including spores of clostridium botulinum. purification of the active compound and genetic characterization of brochocin-c revealed that it is a chromosomally encoded, two-peptide nonlantibiotic bacteriocin. both peptides of brochocin-c are ribosomally synthesized as prepeptides that ar ... | 1998 | 9835559 |
| rho a regulates sustained smooth muscle contraction through cytoskeletal reorganization of hsp27. | the ras-related protein rho p21 regulates various actin-dependent functions, including smooth muscle contraction. however, the precise mechanism of action of rho p21 is still not clear. we report here that rho a is a key regulator of agonist-induced contractile effects in rabbit colonic smooth muscle. endothelin-1 and c2 ceramide were used. both seem to activate phosphoinositide 3-kinase (pi 3-kinase) through g protein and pp60(src), respectively. immunoprecipitation and immunoblotting revealed ... | 1998 | 9843784 |
| cellularization in drosophila melanogaster is disrupted by the inhibition of rho activity and the activation of cdc42 function. | regulation of cytoskeletal dynamics is essential for cell shape change and morphogenesis. drosophila melanogaster embryos offer a well-defined system for observing alterations in the cytoskeleton during the process of cellularization, a specialized form of cytokinesis. during cellularization, the actomyosin cytoskeleton forms a hexagonal array and drives invagination of the plasma membrane between the nuclei located at the cortex of the syncytial blastoderm. rho, rac, and cdc42 proteins are memb ... | 1998 | 9851849 |
| regulation of astrocyte morphology by rhoa and lysophosphatidic acid. | astrocytes in the cns undergo morphological changes and start to proliferate after breakdown of the blood-brain barrier. in culture, proliferating astrocytes have a flat, polygonal shape. when treated with camp-raising agents, astrocytes adopt a stellate, process-bearing morphology resembling their in vivo appearance. stellation is accompanied by loss of actin stress fibers and focal adhesions. lysophosphatidic acid (lpa), a blood-borne mitogen that signals through its cognate g protein-coupled ... | 1998 | 9851865 |
| halothane attenuates calcium sensitization in airway smooth muscle by inhibiting g-proteins. | halothane directly relaxes airway smooth muscle partly by decreasing the ca2+ sensitivity. in smooth muscle, receptor stimulation is thought to increase ca2+ sensitivity via a cascade of heterotrimeric and small monomeric guanine nucleotide-binding proteins (g-proteins). whether this model is applicable in the airway and where halothane acts in this pathway were investigated. | 1998 | 9856731 |
| rhoa-sensitive trafficking of muscarinic acetylcholine receptors. | the clathrin-mediated sequestration pathway is used by non-g protein-coupled receptors (e.g., transferrin receptors) and a large number of g protein-coupled receptors, including beta-2 adrenoceptors and various muscarinic acetylcholine receptor (machr) subtypes. recently, the ubiquitously expressed small gtpase rhoa has been implicated as a negative regulator of transferrin receptor internalization. because machrs and other g protein-coupled receptors are able to activate rhoa, we investigated i ... | 1999 | 9862750 |
| differences in the regulation of fibroblast contraction of floating versus stressed collagen matrices. | to learn more about the regulation of contraction of collagen matrices by fibroblasts, we compared the ability of lysophosphatidic acid (lpa) and platelet-derived growth factor (pdgf) to stimulate contraction of floating and stressed collagen matrices. in floating collagen matrices, pdgf and lpa stimulated contraction with similar kinetics, but appeared to utilize complementary signaling pathways since contraction obtained by the combination of growth factors exceeded that observed with saturati ... | 1999 | 9873032 |
| tyrosine phosphorylation as a convergent pathway of heterotrimeric g protein- and rho protein-mediated ca2+ sensitization of smooth muscle of rabbit mesenteric artery. | 1. the aim of this study was to determine whether different signal transduction mechanisms underlie the ca2+ sensitizing effects of guanosine 5'-o-(3-thiotriphosphate) (gtp(gamma)s) and receptor agonists on beta-escin-skinned smooth muscle of rabbit mesenteric artery. 2. in the homogenate of the beta-escin-skinned arterial strip, c3 exoenzyme of clostridium botulinum catalyzed the [32p]-adp-ribosylation of only one protein that had the same molecular mass as the protein detected in western blots ... | 1998 | 9886756 |
| [botulism in newborn infants]. | infant botulism, first described in 1976, is the most common form of botulism. the majority of cases are reported from the usa. the disease is rare in europe, and this article describes the first patient reported in norway. a three-month-old boy of norwegian origin who had been fed argentinian honey developed symptoms of botulism. electromyography showed presynaptic neuromuscular dysfunction. the diagnosis was confirmed by the demonstration of clostridium botulinum type a neurotoxin in the faece ... | 1998 | 9889606 |
| [wound botulism in heroin addiction]. | botulism is a rare disease which usually is caused by preformed botulinum toxin in food. however, this article describes a case of wound botulism in a 29-year-old male heroin addict who developed progressive diplopia, dysphagia and proximal weakness of skeletal limb muscles. he needed mechanical ventilation for two weeks. the clinical diagnosis of botulism was supported by neurophysiological tests. assays for detection of botulinum toxin and clostridium botulinum were negative. the patient had n ... | 1998 | 9889607 |
| cross-species vaccination in wild and exotic animals. | these are two examples of organisms which may cause morbidity and/or mortality among numerous unrelated species. since it is cost prohibitive in most instances to have a biological licensed for wild or exotic species, it remains a challenge to the zoo or wildlife veterinarian to determine if a licensed vaccine for other species is safe and efficacious for a particular exotic species. | 1999 | 9890042 |
| a tobacco syntaxin with a role in hormonal control of guard cell ion channels. | the plant hormone abscisic acid (aba) regulates potassium and chloride ion channels at the plasma membrane of guard cells, leading to stomatal closure that reduces transpirational water loss from the leaf. the tobacco nt-syr1 gene encodes a syntaxin that is associated with the plasma membrane. syntaxins and related snare proteins aid intracellular vesicle trafficking, fusion, and secretion. disrupting nt-syr1 function by cleavage with clostridium botulinum type c toxin or competition with a solu ... | 1999 | 9915701 |
| a role for rho-like gtpases in the polarisation of mouse eight-cell blastomeres. | polarisation of cells during mouse preimplantation development first occurs within blastomeres at the eight-cell stage, as part of a process called compaction. cell-cell contact mediated by the cell adhesion molecule uvomorulin (e-cadherin) and the activity of the microfilament cytoskeleton are important in the development of compaction, which is crucial for establishment of trophoblast and pluriblast (inner cell mass) lineages and for subsequent development. members of the rho family of p21 gtp ... | 1999 | 9917367 |
| the small gtp-binding protein rho regulates cortical activities in cultured cells during division. | we have investigated the role of the small gtp-binding protein rho in cytokinesis by microinjecting an inhibitor, c3 ribosyltransferase, into cultured cells. microinjection of c3 into prometaphase or metaphase normal rat kidney epithelial cells induced immediate and global cortical movement of actin toward the metaphase plate, without an apparent effect on the mitotic spindle. during anaphase, concentrated cortical actin filaments migrated with separating chromosomes, leaving no apparent concent ... | 1999 | 9922456 |
| characterization of fatty acid composition, spore germination, and thermal resistance in a nisin-resistant mutant of clostridium botulinum 169b and in the wild-type strain. | the membrane fatty acids, thermal resistance, and germination of a nisin-resistant (nisr) mutant of clostridium botulinum 169b were compared with those of the wild-type (wt) strain. in the membranes of wt cells, almost 50% of the total fatty acids were unsaturated, but in those of nisr cells, only 23% of the fatty acids were unsaturated. wt and nisr spores contained similar amounts (approximately 23%) of unsaturated fatty acids, but the saturated straight-chain/branched-chain ratio was significa ... | 1999 | 9925597 |
| [extrachromosomal genetic elements of clostridium botulinum. ii. isolation and analysis of dna from bacteriophages of clostridium botulinum types c and a]. | the dnas of bacteriophage c-st, known to realize the lysogenic conversion of toxinogenicity among c. botulinum types c and d strains, and the nucleic acid of a virulent mutant of bacteriophage cb propagated in type a c. botulinum cells were purified and examined. heterogeneity of phage c-st preparations was observed during purification, manifesting by formation of several bands in isopiknic cscl gradient during centrifuging. an extra nucleic acid fraction was detected in some dna preparations of ... | 1998 | 9987749 |
| rejection of clostridium putrificum and conservation of clostridium botulinum and clostridium sporogenes-opinion 69. judicial commission of the international committee on systematic bacteriology. | the judicial commission rejected the name clostridium putrificum while conserving clostridium botulinum for toxigenic strains and conserving clostridium sporogenes for non-toxigenic strains. | 1999 | 10028279 |
| activation of g12/g13 results in shape change and rho/rho-kinase-mediated myosin light chain phosphorylation in mouse platelets. | platelets respond to various stimuli with rapid changes in shape followed by aggregation and secretion of their granule contents. platelets lacking the alpha-subunit of the heterotrimeric g protein gq do not aggregate and degranulate but still undergo shape change after activation through thromboxane-a2 (txa2) or thrombin receptors. in contrast to thrombin, the txa2 mimetic u46619 led to the selective activation of g12 and g13 in galphaq-deficient platelets indicating that these g proteins media ... | 1999 | 10037795 |
| psychrotrophic clostridia mediated gas and botulinal toxin production in vacuum-packed chilled meat. | a cocktail of washed spores from six psychrotrophic clostridium strains isolated from blown vacuum-packed meats was inoculated onto lamb chumps. a second washed spore cocktail of four toxigenic reference cl. botulinum strains, types a, b (two strains) and e, and a cl. butyricum type e strain, was similarly inoculated onto lamb chumps. all inoculated lamb chumps were individually vacuum-packed and placed into storage at various temperatures typical of good to grossly abusive chilled storage (-1 d ... | 1999 | 10063639 |
| molecular properties of a hemagglutinin purified from type a clostridium botulinum. | clostridium botulinum causes the food poisoning disease botulism by producing botulinum neurotoxin, the most potent toxin known. the neurotoxin is produced along with a group of neurotoxin-associated proteins, or naps, which protect it from the low ph and proteases of the gastrointestinal tract. recently, we isolated one of the major components of naps, a 33-kda hemagglutinin (hn-33) [fu et al. (1998), j. protein chem. 17, 53-60]. in this study, we present molecular properties of hn-33 derived f ... | 1999 | 10071926 |
| in vitro translation of type a clostridium botulinum neurotoxin heavy chain and analysis of its binding to rat synaptosomes. | botulinum neurotoxins (bonts) are highly potent toxins that inhibit neurotransmitter release from peripheral cholinergic synapses. bonts consist of a toxifying light chain (lc; 50 kda) and a binding/translocating heavy chain (hc; 100 kda) linked through a disulfide bond. a dna fragment encoding type a clostridium botulinum heavy chain (bont/a hc) was amplified by polymerase chain reaction and cloned into an e. coli pet-15b vector. in vitro translated [35s]bont/a hc was identified by anti-bont/a ... | 1999 | 10071933 |
| lymphocyte migration through brain endothelial cell monolayers involves signaling through endothelial icam-1 via a rho-dependent pathway. | lymphocyte extravasation into the brain is mediated largely by the ig superfamily molecule icam-1. several lines of evidence indicate that at the tight vascular barriers of the central nervous system (cns), endothelial cell (ec) icam-1 not only acts as a docking molecule for circulating lymphocytes, but is also involved in transducing signals to the ec. in this paper, we examine the signaling pathways in brain ec following ab ligation of endothelial icam-1, which mimics adhesion of lymphocytes t ... | 1999 | 10072547 |
| [diagnosis of clostridium botulinum intoxication]. | | 1999 | 10085583 |
| [food-borne botulism]. | | 1999 | 10088443 |
| activation of protein kinase c by phorbol esters modulates alpha2beta1 integrin on mcf-7 breast cancer cells. | cellular adhesions to other cells and to the extracellular matrix play crucial roles in the malignant progression of cancer. in this study, we investigated the role of protein kinase c (pkc) in the regulation of cell-substratum adhesion by the breast adenocarcinoma cell line mcf-7. a pkc activator, 12-o-tetradecanoylphorbol-l, 3-acetate (tpa), stimulated cell adhesion to laminin and collagen i in a dose-dependent manner over a 1- to 4-h interval. this enhanced adhesion was mediated by alpha2beta ... | 1999 | 10094832 |
| infantile botulism: pitfalls in electrodiagnosis. | botulism in infants, unless recognized early, is associated with high mortality and morbidity. the diagnosis is suspected when infants present with sudden onset of weakness, respiratory failure, and constipation and is confirmed by demonstration of botulinum toxin in stool several weeks later. electrodiagnosis allows quick and reliable confirmation of botulism. low-amplitude compound muscle action potentials, tetanic or post-tetanic facilitation, and the absence of post-tetanic exhaustion suppor ... | 1999 | 10190265 |
| involvement of rhoa and its interaction with protein kinase c and src in cck-stimulated pancreatic acini. | we evaluated intracellular pathways responsible for the activation of the small gtp-binding protein rho p21 in rat pancreatic acini. intact acini were incubated with or without cck and carbachol, and triton x-100-soluble and crude microsomes were used for western immunoblotting. when a rhoa-specific antibody was used, a single band at the location of 21 kda was detected. cck (10 pm-10 nm) and carbachol (0.1-100 microm) dose dependently increased the amount of immunodetectable rhoa with a peak in ... | 1999 | 10198335 |
| bacterial toxins and the rho gtp-binding protein: what microbes teach us about cell regulation. | in the present review activities of two bacterial toxins, clostridium botulinum exoenzyme c3 and escherichia coli cnf1, both acting on the gtp-binding protein rho are analyzed. proteins belonging to the rho family regulate the actin cytoskeleton and act as molecular switches in a number of signal transduction pathways. c3 and cnf1 have opposite effects on rho thus representing useful tools for studies on cell division, cell differentiation and apoptosis. | 1998 | 10200530 |
| outbreak of type a botulism and development of a botulism surveillance and antitoxin release system in argentina. | botulism is an important public health problem in argentina, but obtaining antitoxin rapidly has been difficult because global supplies are limited. in january 1998, a botulism outbreak occurred in buenos aires. | 1999 | 10208152 |
| rho-dependent and -independent tyrosine phosphorylation of focal adhesion kinase, paxillin and p130cas mediated by ret kinase. | glial cell line-derived neurotrophic factor (gdnf) signals through a unique receptor system that includes ret receptor tyrosine kinase and a glycosyl-phosphatidylinositol-linked cell surface protein. in the present study, we have identified several proteins in neuroblastoma cells that are phosphorylated on tyrosine in response to gdnf. the phosphorylated proteins include focal adhesion kinase (fak), paxillin and crk-associated substrate, p130cas, all of which are known to be associated with foca ... | 1999 | 10208419 |
| overexpression of small gtp-binding protein rhoa promotes invasion of tumor cells. | adhesion of tumor cells to host cell layers and subsequent migration are pivotal steps in cancer invasion and metastasis. the small gtp-binding protein rhoa controls cell adhesion and motility through organization of the actin cytoskeleton and regulation of actomyosin contractility. cultured rat mm1 hepatoma cells migrate through a mesothelial cell monolayer in vitro in a serum-dependent, rhoa-mediated manner (k. yoshioka et al., j. biol. chem., 273: 5146-5154, 1998). furthermore, the rock famil ... | 1999 | 10213513 |
| biodiversity of clostridium botulinum type e strains isolated from fish and fishery products. | the genetic biodiversity of clostridium botulinum type e strains was studied by pulsed-field gel electrophoresis (pfge) with two macrorestriction enzymes (smai-xmai and xhoi) and by randomly amplified polymorphic dna (rapd) analysis with two primers (opj 6 and opj 13) to characterize 67 finnish isolates from fresh fish and fishery products, 15 german isolates from farmed fish, and 10 isolates of north american or north atlantic origin derived mainly from different types of seafood. the effects o ... | 1999 | 10224001 |
| growth from spores of nonproteolytic clostridium botulinum in heat-treated vegetable juice. | unheated spores of nonproteolytic clostridium botulinum were able to lead to growth in sterile deoxygenated turnip, spring green, helda bean, broccoli, or potato juice, although the probability of growth was low and the time to growth was longer than the time to growth in culture media. with all five vegetable juices tested, the probability of growth increased when spores were inoculated into the juice and then heated for 2 min in a water bath at 80 degrees c. the probability of growth was great ... | 1999 | 10224012 |
| infantile botulism: an atypical case of an uncommon disease. | | 1999 | 10224186 |
| violations of informed consent during war. | | 1999 | 10235163 |
| the neurology and enterology of equine grass sickness: a review of basic mechanisms. | autonomic dysfunction constitutes a prominent clinical feature of equine grass sickness (egs). significant injury to the nervous control of the alimentary system is life threatening, partly because of dysphagia but also because of the failure of the unique regulatory mechanisms in equine digestion involving water and electrolyte balance. the neuropathology also indicates the presence of a somatic polyneuropathy. the morphological features of egs are similar to those of excitotoxic neuronal degen ... | 1999 | 10320588 |
| nitrite and nitrosyl compounds in food preservation. | nitrite is consumed in the diet, through vegetables and drinking water. it is also added to meat products as a preservative. the potential risks of this practice are balanced against the unique protective effect against toxin-forming bacteria such as clostridium botulinum. the chemistry of nitrite, and compounds derived from it, in food systems and bacterial cells are complex. it is known that the bactericidal species is not nitrite itself, but a compound or compounds derived from it during food ... | 1999 | 10320676 |
| preliminary crystallographic studies of a protease resistant botulinum neurotoxin associated protein hn-33. | botulinum neurotoxin (bont) is one of the most potent toxins known. bont is also a food poison, which means that the toxin must survive the protease action and acidity of the gut. a group of neurotoxin-associated proteins which are only beginning to be identified and characterized are believed to be responsible for this protection. hn-33 is a 33 kda polypeptide which is a major component of the type a botulinum neurotoxin complex. crystals of hn-33 have been grown by vapour-diffusion techniques. ... | 1999 | 10329796 |
| production of recombinant proteins in plant root exudates. | the large-scale production of recombinant proteins in plants is limited by relatively low yields and difficulties in extraction and purification. these problems were addressed by engineering tobacco plants to continuously secrete recombinant proteins from their roots into a simple hydroponic medium. three heterologous proteins of diverse origins (green fluorescent protein of jellyfish, human placental alkaline phosphatase [seap], and bacterial xylanase) were produced using the root secretion met ... | 1999 | 10331806 |
| synergism among lysophosphatidic acid, beta1a integrins, and epidermal growth factor or platelet-derived growth factor in mediation of cell migration. | gd25 cells lacking the beta1 integrin subunit or expressing beta1a with certain cytoplasmic mutations have poor directed cell migration to platelet-derived growth factor (pdgf) or epidermal growth factor (egf), ligands of receptor tyrosine kinases, or to lysophosphatidic acid (lpa), a ligand of g-protein-coupled receptors (sakai, t., zhang, q., fässler, r., and mosher, d. f. (1998) j. cell biol. 141, 527-538 and sakai, t., peyruchaud, o., fässler, r., and mosher, d. f. (1998) j. biol. chem. 273, ... | 1999 | 10336439 |
| [botulism--a forgotten disease?]. | the laboratory diagnosis of c. botulinum is described for cattle and horses in the years 1995-1998. out of 122 cases 66 were positive. all types of toxins were identified; in cattle mainly types c and d. in 9 cases typing was not conclusive. the results of an enquiry of afflicated animal owners showed, that modern agricultural technology has an important impact on toxinogenesis in feed stuff. possibilities to prevent the disease and to reduce economic losses are discussed; a solution cannot be p ... | 1999 | 10337056 |
| effects of cytotoxic necrotizing factor 1 and lethal toxin on actin cytoskeleton and ve-cadherin localization in human endothelial cell monolayers. | integrity of the vascular endothelium is largely dependent on endothelial cell shape and establishment of intercellular junctions. certain pathogenic bacterial toxins alter the cytoskeletal architecture of intoxicated cells by modulating the gtpase activity of p21 rho family proteins. in the present study we have analyzed the effect of rho-directed toxins on the actin cytoskeleton and monolayer integrity of endothelial cells. we report here that escherichia coli cytotoxic necrotizing factor 1 (c ... | 1999 | 10338511 |
| microbiological quality and production of botulinal toxin in film-packaged broccoli, carrots, and green beans. | the production of toxin by a 10-strain mixture of proteolytic clostridium botulinum in fresh produce packaged in polyethylene films with different oxygen permeability was determined. broccoli florets, shredded carrots, and green beans inoculated with approximately 10(2) c. botulinum spores per g were placed in bags (1.4 kg per bag) composed of four films with different oxygen transmission rates (otrs). broccoli was packaged in bags with otrs of 3 (7,000 cm3/m2/24 h) and 4 (16,000 cm3/m2/24 h), a ... | 1999 | 10340671 |
| enhancement of the endopeptidase activity of botulinum neurotoxin by its associated proteins and dithiothreitol. | botulinum neurotoxins type a (bont/a), the most toxic substance known to man, is produced by clostridium botulinum type a as a complex with a group of neurotoxin-associated proteins (naps), possibly through a polycistronic expression of a clustered group of genes. the botulinum neurotoxin complex is the only known example of a protein complex where a group of proteins (naps) protect another protein (bont) against acidity and proteases of the gi tract. we now report that naps also potentiate the ... | 1999 | 10346912 |
| [studies on the receptor for clostridium botulinum neurotoxin]. | | 1999 | 10356952 |
| ribotyping as an identification tool for clostridium botulinum strains causing human botulism. | ribotyping was used for characterisation of 68 clostridium botulinum strains and five related clostridium species to determine the applicability of this method for identification of species causing human botulism. thirteen restriction enzymes were initially tested for suitability for ribotyping of c. botulinum, of which ecori and hindiii were selected. both enzymes clearly differentiated between proteolytic (group i) and a nonproteolytic (group ii) strains of c. botulinum, and can be recommended ... | 1999 | 10357280 |
| predicted and observed growth and toxigenesis by clostridium botulinum type e in vacuum-packaged fishery product challenge tests. | the observed growth and toxigenesis by clostridium botulinum type e in vacuum-packaged unprocessed, raw pickled and cold-smoked rainbow trout stored at slightly abusive temperatures were compared to predictions generated by two currently available predictive microbiological programs, food micromodel and pathogen modelling program. in unprocessed fish there was only a 2 log increase in type e cell count at the time the toxicity first occurred after 2 weeks storage at 8 degrees c. neither growth o ... | 1999 | 10359486 |