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| Registros recuperados: 33 | |
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| Onofre,Sideney Becker; Riveros Gonzalez,Raul; Messias,Cláudio Luiz; Azevedo,João Lúcio; Barros,Neiva Monteiro de. |
| The entomopathogenic fungus Nomuraea rileyi (Farlow) Samson produced a peptide active against Anticarsia gemmatalis 3rd instar larvae. To produce this peptide, N. rileyi was cultivated aerobically in Saboraud, maltose, yeast-extract broth at 26 ± 1ºC for 12 days, after which the medium was filtered and separated in a liquid/liquid extractor, concentrated and the peptide purified chromatographically. The crystals obtained were kept refrigerated until needed for LC50 analysis. The LC50 of this peptide against A. gemmatalis 3rd instar larvae was determined in triplicate experiments using solutions containing 1.0, 0.2, 0.1, 0.01, 0.001 and 0.0001 mg/ml of N. rileyi peptide. The results of these experiments were used to calculate a linear equation in which Y =... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anticarsia gemmatalis; Nomuraea rileyi; Integrated control; Secondary metabolite; Toxins. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132002000300004 |
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| The possibility of producing neutralizing antibodies against the lethal effects of scorpion toxins was evaluated in the mouse model by immunization with an immunogen devoid of toxicity. A toxic fraction (5 mg) from the venom of the scorpion Tityus serrulatus was entrapped in sphingomyelin-cholesterol liposomes. The liposomes were treated for 1 h at 37oC with a 1% (w/w) trypsin solution in 0.2 M sodium carbonate buffer, pH 8.3. This treatment led to a strong reduction in venom toxicity. Immunization was performed as follows: mice were injected sc with 20 µg of the liposome-entrapped toxic fraction on days 1 and 21 and a final injection (20 µg) was administered ip on day 36. After injection of the immunogen, all mice developed an IgG response which was shown... |
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Palavras-chave: Liposomes; Neutralizing antibodies; Tityus serrulatus; Immunization; Toxins. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000700010 |
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| Vasconcelos,V.M.. |
| Toxic cyanobacteria are common in Portuguese freshwaters and the most common toxins are microcystins. The occurrence of microcystin-LR (MCYST-LR) has been reported since 1990 and a significant number of water reservoirs that are used for drinking water attain high levels of this toxin. Aquatic animals that live in eutrophic freshwater ecosystems may be killed by microcystins but in many cases the toxicity is sublethal and so the animals can survive long enough to accumulate the toxins and transfer them along the food chain. Among these, edible mollusks, fish and crayfish are especially important because they are harvested and sold for human consumption. Mussels that live in estuarine waters and rivers where toxic blooms occur may accumulate toxins without... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cyanobacteria; Toxins; Risk; Human health; Microcystins; Accumulation. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000300001 |
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| Vidotto,Marilda C.; Lima,Natália C.S. de; Fritzen,Juliana T.T.; Freitas,Júlio C. de; Venâncio,Emerson J.; Ono,Mario A.. |
| Identification of Escherichia coli causing porcine postweaning diarrhea requires knowledge regarding the prevalent pathotypes within a given region. A total of 100Escherichia coli isolates from piglets with diarrhea in Londrina city, Parana State, South Brazil, were screened for the presence of genes for F4, F5, F6, F18, F41 fimbrial antigens by specific probes and for enterotoxins (STa, STb, LT and STx2e) by polymerase chain reaction (PCR). The results showed that 60% of the isolates were positive for one or more of the fimbrial antigens and 92% were positive at least for one of the virulence factors examined. Virulence factor genes detected were F4 (44%), F18 (38%), F5 (30%), F41 (32%), F6 (25%), LTp-I (71%), STa (40%), STb (47%) and STx2e (3%). Twenty... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Porcine Escherichia coli; Virulence genes; Postweaning diarrhea; Toxins. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000100035 |
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| Stojanovic,Predrag; Kocic,Branislava; Stojanovic,Miodrag; Miljkovic-Selimovic,Biljana; Tasic,Suzana; Miladinovic-Tasic,Natasa; Babic,Tatjana. |
| The aim of this study was to fortify the clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile isolated from stool samples of hospitalized patients. This survey included 80 hospitalized patients with diarrhea and positive findings of Clostridium difficile in stool samples, and 100 hospitalized patients with formed stool as a control group. Bacteriological examination of a stool samples was conducted using standard microbiological methods. Stool sample were inoculated directly on nutrient media for bacterial cultivation (blood agar using 5% sheep blood, Endo agar, selective Salmonella Shigella agar, Selenite-F broth, CIN agar and Skirrow's medium), and to selective cycloserine-cefoxitin-fructose agar (CCFA) (Biomedics,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clostridium difficile; Diarrhea; Toxins. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000100023 |
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| Ferreira,Thais Sebastiana Porfida; Moreno,Andrea Micke; Almeida,Renata Rodrigues de; Gomes,Cleise Ribeiro; Gobbi,Debora Dirani Sena de; Filsner,Pedro Henrique Nogueira de Lima; Moreno,Marina. |
| Clostridium perfringens is an anaerobic Gram-positive bacterium known as common pathogen for humans, for domestic and wildlife animals. Although infections caused by C. perfringens type C and A in swine are well studied, just a few reports describe the genetic relationship among strains in the epidemiological chain of swine clostridioses, as well as the presence of the microorganism in the slaughterhouses. The aim of the present study was to isolate C. perfringens from feces and carcasses from swine slaughterhouses, characterize the strains in relation to the presence of enterotoxin, alpha, beta, epsilon, iota and beta-2 toxins genes, using polymerase chain reaction (PCR) and comparing strains by means of Pulsed field gel electrophoresis (PFGE).... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clostridium perfringens; Swine; Slaughterhouse; PFGE; Carcass; Toxins. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782012000800020 |
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| Medhioub, Walid; Ramondenc, Simon; Vanhove, Audrey; Vergnes, Agnes; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc. |
| This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h,... |
| Tipo: Text |
Palavras-chave: Shellfish; Toxins; Apoptosis; Gene expression. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28744/27213.pdf |
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| Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille. |
| To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French... |
| Tipo: Text |
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf |
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| Couet, Douglas; Pringault, Olivier; Bancon-montigny, Chrystelle; Briant, Nicolas; Poulichet, Francoise Elbaz; Delpoux, Sophie; Yahia, Ons Kefi-daly; Hela, Bengharbia; Charaf, M'Rabet; Herve, Fabienne; Rovillon, Georges-augustin; Amzil, Zouher; Laabir, Mohamed. |
| Controlled laboratory experiments were conducted to test the effects of copper (Cu2+) and butyltins (BuT) on the growth, photosynthetic activity and toxin content of two HABs (Harmful Algal Blooms) dinoflagellates, the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata. Microalgae were exposed to increasing concentrations of Cu2+ (10−4 to 31 nM) or BuT (0.084 to 84 nM) for seven days. When considering the growth, EC50 values were 0.16 (±0.09) nM and 0.03 (±0.02) nM of Cu2+ for A. catenella and O. cf. ovata, respectively. Regarding BuT, EC50 was 14.2 (±6) nM for O. cf. ovata, while A. catenella growth inhibition appeared at BuT concentrations ≥27 nM. Photosynthetic activity of the studied dinoflagellates decreased with increasing Cu and... |
| Tipo: Text |
Palavras-chave: Alexandrium catenella; Ostreopsis cf. ovata; Cu; Butyltin; Photosynthesis; Toxins. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00418/52970/53896.pdf |
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| Perez-pascual, David; Lunazzi, Aurelie; Magdelenat, Ghislaine; Rouy, Zoe; Roulet, Alain; Lopez-roques, Celine; Larocque, Robert; Barbeyron, Tristan; Gobet, Angelique; Michel, Gurvan; Bernardet, Jean-francois; Duchaud, Eric. |
| Tenacibaculum maritimum is a devastating bacterial pathogen of wild and farmed marine fish with a broad host range and a worldwide distribution. We report here the complete genome sequence of the T. maritimum type strain NCIMB 2154(T). The genome consists of a 3,435,971-base pair circular chromosome with 2,866 predicted protein-coding genes. Genes encoding the biosynthesis of exopolysaccharides, the type IX secretion system, iron uptake systems, adhesins, hemolysins, proteases, and glycoside hydrolases were identified. They are likely involved in the virulence process including immune escape, invasion, colonization, destruction of host tissues, and nutrient scavenging. Among the predicted virulence factors, type IX secretion-mediated and cell-surface... |
| Tipo: Text |
Palavras-chave: Tenacibaculum maritimum; Fish pathogen; Virulence factors; Genome; Toxins. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00488/59939/63150.pdf |
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| Tetreau, Guillaume. |
| Toxins are a major virulence factor produced by many pathogenic bacteria. In vertebrates, the response of hosts to the bacteria is inseparable from the response to the toxins, allowing a comprehensive understanding of this tripartite host-pathogen-toxin interaction. However, in invertebrates, this interaction has been investigated by two complementary but historically distinct fields of research: toxinology and immunology. In this article, I highlight how such dichotomy between these two fields led to a biased, or even erroneous view of the ecology and evolution of the interaction between insects, toxins, and bacteria. I focus on the reason behind such a dichotomy, on how to bridge the fields together, and on confounding effects that could bias the outcome... |
| Tipo: Text |
Palavras-chave: Invertebrate immunity; Host-pathogens interaction; Toxins; Bacillus thuringiensis; Resistance. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00457/56834/78950.pdf |
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| LIPPS,B. V.. |
| Lethal Toxin Neutralizing Factor (N-LTNF), MW 63.0 kDa, was isolated from opossum serum. After trypsin digestion, the active domain of N-LTNF was isolated and sequenced. The synthetic peptide consisting of ten amino acids was designated as LT-10. N-LTNF and LT-10 inhibited the lethality of animal, plant and bacteria toxins when tested on mice non-immunologically. The antibodies against N-LTNF and LT-10 only reacted immunologically with toxins and not with non-toxic substances. Anti-LTNF and anti-LT-10 reacted immunologically by ELISA test with toxins that were not detected by mouse test, such as cholera toxin and digoxin. Anti-LTNF and anti-LT-10 failed to react immunologically with non-toxic substances, such as nerve growth factor and collagen. Currently,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antibodies; In vitro assay; Lethal toxin neutralizing factor; Toxins; Venoms. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-79302002000200003 |
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| Barbosa,Alexandre Naime; Boyer,Leslie; Chippaux,Jean-Philippe; Medolago,Natalia Bronzatto; Caramori,Carlos Antonio; Paixão,Ariane Gomes; Poli,João Paulo Vasconcelos; Mendes,Mônica Bannwart; Santos,Lucilene Delazari dos; Ferreira Jr,Rui Seabra; Barraviera,Benedito. |
| Abstract Background Envenomation caused by multiple stings from Africanized honeybees Apis mellifera constitutes a public health problem in the Americas. In 2015, the Brazilian Ministry of Health reported 13,597 accidents (incidence of seven cases per 100,000 inhabitants) with 39 deaths (lethality of 0.25%). The toxins present in the venom, which include melittin and phospholipase A2, cause lesions in diverse organs and systems that may be fatal. As there has been no specific treatment to date, management has been symptomatic and supportive only. Methods In order to evaluate the safety and neutralizing capacity of a new apilic antivenom, as well as to confirm its lowest effective dose, a clinical protocol was developed to be applied in a multicenter,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Apis mellifera; Bee venom; Toxins; Envenomation; Heterologous serum; Apilic antivenom; Bee antivenom. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100309 |
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| Sciani,Juliana Mozer; Zychar,Bianca; Gonçalves,Luis Roberto; Giorgi,Renata; Nogueira,Thiago; Pimenta,Daniel Carvalho. |
| Abstract Background Sea urchins are animals commonly found on the Brazilian shoreline, being Echinometra lucunter the most abundant species. Accidents caused by E. lucunter have been reported as one of the most frequent in Brazil, and are characterized by intense pain and inflammation, consequence of spine puncture in the skin. In order to characterize such toxic effects, we isolated one molecule that caused inflammatory and nociceptive effects. Methods E. lucunter specimens were collected without gender distinction. Spines were removed and molecules were extracted, fractionated by RP-HPLC and assayed for inflammatory and nociceptive activity, in a biological-driven fractionation way, until the obtainment of one active molecule and its subsequent... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Toxins; Sea urchin; Echinometra lucunter; Spines; Inflammation. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100318 |
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| Chaves-Moreira,Daniele; Senff-Ribeiro,Andrea; Wille,Ana Carolina Martins; Gremski,Luiza Helena; Chaim,Olga Meiri; Veiga,Silvio Sanches. |
| Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4–40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brown spider; Loxosceles; Venom; Toxins; Loxoscelism; Phospholipase-D; Metalloprotease; Insecticidal peptides; Serineprotease; Hyaluronidase. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100201 |
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| Registros recuperados: 33 | |
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