Effects of intravenous injection of Clostridium perfringens type D epsilon toxin in calves

In cattle, a neurological lesion similar to that produced in sheep and goats by Clostridium perfringens type D enterotoxaemia has been reported. However, no causal relationship has been established between this disease and the lesion in cattle. The effects of single and multiple intravenous injections of epsilon toxin in three calves aged 6 months were studied. A further calf was inoculated intravenously with saline solution and used as a control. Epsilon toxin invariably produced neurological signs within 2-60 min of the end of the injection process. Clinical signs consisted of loss of consciousness, recumbency, convulsions, paddling, opisthotonus, hyperaesthesia and dyspnoea. Gross changes consisted of severe acute pulmonary oedema, which was particularly marked in the interlobular septa. The histological lesions consisted of intra-alveolar and interstitial oedema of the lung and variable degrees of perivascular proteinaceous oedema in the internal capsule, thalamus and cerebellar white matter. No clinical or post-mortem changes were observed in the control calf. These results show that calves are susceptible to the intravenous injection of epsilon toxin, and that they can show at least some of the histological lesions produced in sheep and goats by this toxin. (C) 2002 Harcourt Publishers Ltd.

Correlation between in vitro cytotoxicity and in vivo lethal activity in mice of epsilon toxin mutants from Clostridium perfringens

Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect the membrane insertion domain behaved as dominant-negative inhibitors of toxin activity in MDCK cells. We produced similar mutants, together with a well-known non-toxic mutant (Etx-H106P), as green fluorescent protein (GFP) fusion proteins to perform in vivo studies in an acutely intoxicated mouse model. The mutant (GFP-Etx-I51C/A114C) had a lethal effect with generalized edema, and accumulated in the brain parenchyma due to its ability to cross the blood-brain barrier (BBB). In the renal system, this mutant had a cytotoxic effect on distal tubule epithelial cells. The other mutants studied (GFP-Etx-V56C/F118C and GFP-Etx-H106P) did not have a lethal effect or cross the BBB, and failed to induce a cytotoxic effect on renal epithelial cells. These data suggest a direct correlation between the lethal effect of the toxin, with its cytotoxic effect on the kidney distal tubule cells, and the ability to cross the BBB.

Naturally acquired antibodies against Clostridium perfringens epsilon toxin in goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cellular vacuolation and mitochondrial-associated factors induced by Clostridium perfringens epsilon toxin detected using acoustic flow cytometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Kinetics of epsilon antitoxin antibodies in different strategies for active immunization of lambs against enterotoxaemia

Enterotoxaemia, a common disease that affects domestic small ruminants, is mainly caused by the epsilon toxin of Clostridium perfringens type D. The present study tested four distinct immunization protocols to evaluate humoral response in lambs, a progeny of non-vaccinated sheep during gestation. Twenty-four lambs were randomly allocated into four groups according to age (7, 15, 30 and 45 days), receiving the first dose of epsilon toxoid commercial vaccine against clostridiosis with booster after 30 days post vaccination. Indirect ELISA was performed after the first vaccine dose and booster to evaluate the immune response of the lambs. Results showed that for the four protocols tested all lambs presented serum title considered protective (≥0.2UI/ml epsilon antitoxin antibodies) and also showed that the anticipation of primovaccination of lambs against enterotoxaemia conferred serum title considered protective allowing the optimization of mass vaccination of lambs.

Kinetics of epsilon antitoxin antibodies in different strategies for active immunization of lambs against enterotoxaemia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Focal symmetrical encephalomalacia in sheep

Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia by Clostridium perfringens type D. This paper reports FSE in sheep in Brazil. Six deaths occurred within a seven days period in a flock of 70, four to 30-month-old Santa Inês sheep in the state of Paraíba in the Brazilian semiarid. The flock was grazing a paddock of irrigated sprouting Cynodon dactylon (Tifton grass), and supplemented, ad libitum, with a concentrate of soybean, corn and wheat. Nervous signs included blindness and recumbence. A 19 month-old sheep was examined clinically and necropsied after a clinical course of three days. Gross lesions were herniation of the cerebellar vermis and multifocal, bilateral, symmetric brownish areas in the internal capsule, thalamus and cerebellar peduncles. Histologic lesions were multifocal, bilateral malacia with some neutrophils, swelling of blood vessels endothelium, perivascular edema, and hemorrhages. The flock was vaccinated, before the outbreak, with only one dose of Clostridium perfringens type D vaccine. Two factors are suggested to be important for the occurrence of the disease: insufficient immunity due to the incorrect vaccination; and high nutritional levels by the supplementation with highly fermentable carbohydrates.

Necrotizing enteritis associated with Clostridium perfringensType B in chinchillas (Chinchilla lanigera)

Four 3-4 month-old chinchillas (Chinchilla lanigera) from a commercial flock of 395 chinchillas, were found dead with evidence of previous diarrhea and prolapsed rectum. A fifth 8 month-old chinchilla died 8 hours after being found recumbent, apathetic, diarrheic and with a prolapsed rectum. Two chinchillas were necropsied and observed gross lesions consisted of extensive hemorrhagic enteritis, mild pulmonary edema and enlarged and yellow liver; this latter finding was particularly prominent in the chinchilla presenting longer clinical course. Histologically there was necrotizing enteritis associated with abundant bacterial rods aggregates in the intestinal surface epithelium and within the lamina propria. In the lungs there were small amounts of pink proteinaceous material (edema) in the interstitium and marked vacuolar hepatocellullar degeneration (lipidosis) in the liver. Anaerobic cultures from the intestinal contents of one of the affected chinchillas yielded Clostridium perfringens. Genotyping of this C. perfringens isolate was achieved by multiplex polymerase chain reaction (mPCR) as C. perfringenstype B due to detection of alpha, beta and epsilon-toxin genes. These findings suggest C. perfringens type B as an important cause of sudden or acute death in chinchillas.

Cinética dos anticorpos de origem colostral contra a toxina épsilon de Clostridium perfringens tipo D em cordeiros

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do efeito da toxina épsilon do clostridium perfringens em monocamadas de células MDCK (Madin-Darby canine kidney cell)

Pós-graduação em Ciência Animal - FMVA

Avaliação sorológica de cordeiros submetidos a diferentes protocolos de imunoprofilaxia da enterotoxemia causada pela ação da toxina épsilon do Clostridium perfrigens tipo D

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sorological evaluation of commercial vaccines against enterotoxemia in goats.

Enterotoxemia in sheep and in goats is caused by the effects of the epsilon toxin of C/ostridium perfringens type D, being considered the main infectious cause of mortality in those animal species. The main prophylactic measures include adequate nutritional management and vaccination of ali animais using vaccines of high immunogenic power. Six commercial vaccines containing in its formulation the epsilon toxoid of C. perfringens type D were sorogically evaluated. Eighty four female goat kids, whose mothers had no previous vaccination history against clostridioses were used. They were divided into six groups of 14 animais each. The animais of the control group didn't receive any vaccine dose and the animais from the groups 1 to 5 received two vaccine doses, The first vaccine dose was applied at 45 days of life (day zero) and the second dose at 75 days (30 days after the first dose). Blood samples were collected from the goat kids at the days zero, 30, 60, 90, 120 and 150 after the beginning of the experiment, in order to evaluate the immunologic response. The Indirect ELlSA technique was used for the quantification of the antibodies against epsilon toxin in the samples of blood serum of the animais. In day zero, no animal presented titre considered protector. The largest number of animais considered protected was found at day 60, in response to the two initial doses of the vaccine (days O and 30, first and second doses, respectively). Only tive animaIs which received the vaccine 1 and one animal which received the vaccine 3 stayed wilh titres of antibodies considered up to 150 days after the first vaccine dose. Based on the results, it was concluded lhat the evaluated vaccines showed small amount of epsilon toxoid in the commercial formulations, a crucial fact for lhe low efficiency of. the vaccines. For commercial reasons, the vaccines against the clostridioses present versatile formulations, with several toxoid types, used for various animal species, which certainly contributed to reduce their effectiveness in preventing the iIInesses caused by the clostridia or their toxins.

Shiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in Sao Paulo, Brazil

Aims: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent. Methods and Results: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx(1), stx(2), eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)-PCR was performed to investigate the variants of stx(1) and stx(2), and the flagellar antigen (fliC) genes in nonmotile isolates. Five isolates were eae(+) and stx(-), and belonged to serotypes O128:H2/beta-intimin (2), O145:H2/gamma, O153:H7/beta and O178:H7/epsilon. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx(1c)stx(2d-O118) (46.9%), stx(1c) (27.2%), stx(2d-O118) (23.4%), and stx(1c)stx(2dOX3a) (2.5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates. Conclusions: This study demonstrated that healthy sheep in Sao Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC. Significance and Impact of the Study: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.

Detection of A/B toxin and isolation of Clostridium difficile and Clostridium perfringens from foals

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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.