RESUMO
The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.(AU)
Assuntos
Mapeamento de Epitopos , Clostridium perfringens/química , Enterotoxemia , Toxinas BiológicasRESUMO
Abstract The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.
Assuntos
Animais , Toxinas Bacterianas/química , Clostridium perfringens/imunologia , Epitopos/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Clostridium perfringens/química , Clostridium perfringens/genética , Enterotoxemia/microbiologia , Mapeamento de Epitopos , Epitopos/genética , Epitopos/imunologiaRESUMO
The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.
Assuntos
Toxinas Bacterianas/química , Clostridium perfringens/imunologia , Epitopos/química , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Clostridium perfringens/química , Clostridium perfringens/genética , Enterotoxemia/microbiologia , Mapeamento de Epitopos , Epitopos/genética , Epitopos/imunologiaRESUMO
This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.
Assuntos
Queijo/microbiologia , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/fisiologia , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Aderência Bacteriana , Brasil , Fenômenos Químicos , Ácidos Cólicos/metabolismo , Ácidos Cólicos/toxicidade , Clostridium perfringens/química , Clostridium perfringens/fisiologia , Enterococcus faecium/química , Escherichia coli/química , Escherichia coli/fisiologia , Trato Gastrointestinal/química , Interações Hidrofóbicas e Hidrofílicas , Inativação Metabólica , Viabilidade Microbiana/efeitos dos fármacos , Reação em Cadeia da Polimerase , Fatores de Virulência/análise , Fatores de Virulência/genéticaRESUMO
This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens. Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.
Assuntos
Queijo/microbiologia , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/fisiologia , Inocuidade dos Alimentos , Manipulação de Alimentos/métodos , Aderência Bacteriana , Brasil , Fenômenos Químicos , Ácidos Cólicos/metabolismo , Ácidos Cólicos/toxicidade , Clostridium perfringens/química , Clostridium perfringens/fisiologia , Enterococcus faecium/química , Escherichia coli/química , Escherichia coli/fisiologia , Trato Gastrointestinal/química , Interações Hidrofóbicas e Hidrofílicas , Inativação Metabólica , Viabilidade Microbiana/efeitos dos fármacos , Reação em Cadeia da Polimerase , Fatores de Virulência/análise , Fatores de Virulência/genéticaRESUMO
This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens. Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.(AU)
Assuntos
Queijo/microbiologia , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/fisiologia , Manipulação de Alimentos/métodos , Aderência Bacteriana , Brasil , Ácidos Cólicos/metabolismo , Ácidos Cólicos/toxicidade , Clostridium perfringens/químicaRESUMO
The substitution of serine and threonine residues in nucleocytoplasmic proteins with 2-acetamido-2-deoxy-ß-D-glucopyranose (O-GlcNAc) residues is an essential post-translational modification found in many multicellular eukaryotes. O-glycoprotein 2-acetamino-2-deoxy-ß-D-glucopyranosidase (O-GlcNAcase) hydrolyzes O-GlcNAc residues from post-translationally modified serine/threonine residues of nucleocytoplasmic protein. O-GlcNAc has been implicated in several disease states such as cancer, Alzheimer's disease, and type II diabetes. For this paper, a model of the human O-GlcNAcase (hOGA) enzyme based on the X-ray structures of bacterial Clostridium perfringens (CpNagJ) and Bacteroides thetaiotaomicrometer (BtOGA) homologues has been generated through molecular homology modeling. In addition, molecular docking, molecular dynamics (MD) simulations, and Linear Interaction Energy (LIE) were employed to determine the bind for derivatives of two potent inhibitors: O-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc) and 1,2-dideoxy-2'-methyl-R-D-glucopyranoso-[2,1-d]-Δ2'-thiazoline (NAG-thiazoline), with hOGA. The results show that the binding free energy calculations using the Linear Interaction Energy (LIE) are correlated with inhibition constant values. Therefore, the model of the human O-GlcNAcase (hOGA) obtained here may be used as a target for rational design of new inhibitors.
Assuntos
Acetilglucosamina/análogos & derivados , Proteínas de Bactérias/química , Simulação de Acoplamento Molecular , Oximas/química , Fenilcarbamatos/química , Tiazóis/química , beta-N-Acetil-Hexosaminidases/química , Acetilglucosamina/química , Proteínas de Bactérias/antagonistas & inibidores , Bacteroides/química , Bacteroides/enzimologia , Sítios de Ligação , Clostridium perfringens/química , Clostridium perfringens/enzimologia , Cristalografia por Raios X , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/química , Cinética , Ligantes , Ligação Proteica , Conformação Proteica , Homologia Estrutural de Proteína , Termodinâmica , beta-N-Acetil-Hexosaminidases/antagonistas & inibidoresRESUMO
Clostridium perfringens is the causative agent of a variety of histotoxic infections in humans and animals. Studies on the early events of C. perfringens infections have been largely focused on the interactions between their vegetative cells and macrophages. Consequently, in the current study we have examined the interactions between C. perfringens spores and Raw 264.7 macrophages. Raw 264.7 cells were able to interact and phagocytose Clostridium perfringens spores of a food poisoning isolate, strain SM101, and a non-food borne isolate, strain F4969, albeit to different extents. Phagocytosis and to a lesser extent, association, of C. perfringens spores by Raw 2647 macrophages was completely inhibited in presence of cytochalasin D. Complement increased association and phagocytosis of C. perfringens spores by Raw 264.7 macrophages. Survival of C. perfringens spores during macrophage infection seems to depend on the ability of spore germination during infection as: (i) F4969 spores germinated during infection with Raw 264.7 macrophages and subsequently killed by macrophages; and (ii) SM101 spores remained dormant inside Raw 264.7 macrophages and thus survived up to 24 h of infection. The in vitro spore-resistance factors, α/ß-type SASP, SpmA/B proteins and spore's core water content, seems to play no role in mediating SM101 spore-resistance to macrophages. Collectively, these results might well have implications in understanding the initial stages of infections by C. perfringens spores.
Assuntos
Clostridium perfringens/fisiologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Actinas/metabolismo , Animais , Linhagem Celular , Clostridium perfringens/química , Clostridium perfringens/imunologia , Proteínas do Sistema Complemento/metabolismo , Interações Hospedeiro-Patógeno , Macrófagos/imunologia , Camundongos , Viabilidade Microbiana/imunologia , Fagocitose , Multimerização Proteica , Esporos Bacterianos , Água/químicaRESUMO
Enterotoxemia, uma das mais importantes enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a cinética de anticorpos colostrais antitoxina épsilon em cordeiros nascidos de ovelhas submetidas a dois diferentes tipos de manejo sanitário. Um grupo de ovelhas prenhes (n=6) foi vacinado com uma dose única de vacina comercial polivalente contra clostridioses contendo toxóide épsilon na sua formulação cerca de 30 dias antes da data prevista para a parição. Outro grupo de ovelhas (n=6) de mesma idade gestacional não foi vacinado. Imediatamente após o parto, antes da ingestão do colostro, foram colhidas amostras sanguíneas dos respectivos cordeiros, bem como aos 30 e 60 dias de idade e submetidas à avaliação sorológica pelo teste de ELISA indireto. Os resultados encontrados permitem concluir que a vacinação de ovelhas prenhes 30 dias antes do parto contra a enterotoxemia causada pela toxina épsilon, com dose única de produto comercial, induz imunidade passiva em níveis considerados protetores (>0,5UI/ml) aos cordeiros por, no mínimo, 60 dias de idade.(AU)
Enterotoxemia, a disease that affect small ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. This study evaluated the kinetics of epsilon antitoxin colostral antibodies in lambs born to ewes submitted to two different types of health management. A group of pregnant ewes (n=6) was vaccinated with a single dose of commercial vaccine against polyvalent clostridial toxoid containing epsilon in its formulation some 30 days before the expected date of birth. Another group of ewes (n=6) of the same gestational age were not vaccinated. Immediately after birth, before intake of colostrum, blood samples were collected from their lambs as well as 30 and 60 days of age for serum evaluation by ELISA. The results allow to conclude that vaccination of pregnant ewes 30 days before parturition allowed the transfer of colostral antibodies specific enough to guarantee the immunity considered protective (0,5UI/ml) of the newborn lamb against enterotoxemia until its entry into the feedlot, with 60 days of age.(AU)
Assuntos
Ovinos/imunologia , Clostridium perfringens/química , Bactérias Anaeróbias/patogenicidadeRESUMO
Enterotoxemia, uma das mais importantes enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a cinética de anticorpos colostrais antitoxina épsilon em cordeiros nascidos de ovelhas submetidas a dois diferentes tipos de manejo sanitário. Um grupo de ovelhas prenhes (n=6) foi vacinado com uma dose única de vacina comercial polivalente contra clostridioses contendo toxóide épsilon na sua formulação cerca de 30 dias antes da data prevista para a parição. Outro grupo de ovelhas (n=6) de mesma idade gestacional não foi vacinado. Imediatamente após o parto, antes da ingestão do colostro, foram colhidas amostras sanguíneas dos respectivos cordeiros, bem como aos 30 e 60 dias de idade e submetidas à avaliação sorológica pelo teste de ELISA indireto. Os resultados encontrados permitem concluir que a vacinação de ovelhas prenhes 30 dias antes do parto contra a enterotoxemia causada pela toxina épsilon, com dose única de produto comercial, induz imunidade passiva em níveis considerados protetores (>0,5UI/ml) aos cordeiros por, no mínimo, 60 dias de idade.
Enterotoxemia, a disease that affect small ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. This study evaluated the kinetics of epsilon antitoxin colostral antibodies in lambs born to ewes submitted to two different types of health management. A group of pregnant ewes (n=6) was vaccinated with a single dose of commercial vaccine against polyvalent clostridial toxoid containing epsilon in its formulation some 30 days before the expected date of birth. Another group of ewes (n=6) of the same gestational age were not vaccinated. Immediately after birth, before intake of colostrum, blood samples were collected from their lambs as well as 30 and 60 days of age for serum evaluation by ELISA. The results allow to conclude that vaccination of pregnant ewes 30 days before parturition allowed the transfer of colostral antibodies specific enough to guarantee the immunity considered protective (0,5UI/ml) of the newborn lamb against enterotoxemia until its entry into the feedlot, with 60 days of age.