Tobacco Seed-Based Oral Vaccination against Verocytotoxic O138 Escherichia coli as Alternative Approach to Antibiotics in Weaned Piglets (original) (raw)
Related papers
Veterinary Research Communications, 2014
The use of transgenic plants as delivery system for antigenic proteins is attractive for its simplicity and increases likelihood for local immune response at sites of infection. The aim of this study was to evaluate the protective effect of oral administration of tobacco seeds, expressing the FedA, the major protein of the F18 adhesive fimbriae, and B subunit of verocytotoxin, against verocytotoxin-producing E. coli (VTEC) strain in piglets. Forty-three early weaned piglets, were randomly divided into 4 experimental groups: 3 test groups and a control. Treatment groups orally received a bolus, with different dose of tobacco seeds on 0, 1, 2, 14 days post primary administration. After challenge, with 1*10 10 CFU of O138 Escherichia coli strain, piglets showed clinical scores significantly higher in the control group compared to orally immunized groups (P <0.05) and the latter showed a faster recovery than in CG. In conclusion, oral administration of recombinant tobacco seeds expressing antigenic proteins against VTEC strains can induce a protective effect against challenger strain in piglets.
Verocytotoxic Escherichia (E.) coli strains are responsible for swine oedema disease, which is an enterotoxaemia that causes economic losses in the pig industry. The production of a vaccine for oral administration in transgenic seeds could be an efficient system to stimulate local immunity. This study was conducted to transform tobacco plants for the seed-specific expression of antigenic proteins from a porcine verocytotoxic E. coli strain. Parameters related to an immunological response and possible adverse effects on the oral administration of obtained tobacco seeds were evaluated in a mouse model. Tobacco was transformed via Agrobacteium tumefaciens with chimeric constructs containing structural parts of the major subunit FedA of the F18 adhesive fimbriae and VT2e B-subunit genes under control of a seed specific GLOB promoter. We showed that the foreign Vt2e-B and F18 genes were stably accumulated in storage tissue by the immunostaining method. In addition, Balb-C mice receiving transgenic tobacco seeds via the oral route showed a significant increase in IgA-positive plasma cell presence in tunica propria when compared to the control group with no observed adverse effects. Our findings encourage future studies focusing on swine for evaluation of the protective effects of transformed tobacco seeds against E. coli infection.
Journal of Veterinary Science, 2013
Verocytotoxic Escherichia (E.) coli strains are responsible for swine oedema disease, which is an enterotoxaemia that causes economic losses in the pig industry. The production of a vaccine for oral administration in transgenic seeds could be an efficient system to stimulate local immunity. This study was conducted to transform tobacco plants for the seed-specific expression of antigenic proteins from a porcine verocytotoxic E. coli strain. Parameters related to an immunological response and possible adverse effects on the oral administration of obtained tobacco seeds were evaluated in a mouse model. Tobacco was transformed via Agrobacteium tumefaciens with chimeric constructs containing structural parts of the major subunit FedA of the F18 adhesive fimbriae and VT2e B-subunit genes under control of a seed specific GLOB promoter. We showed that the foreign Vt2e-B and F18 genes were stably accumulated in storage tissue by the immunostaining method. In addition, Balb-C mice receiving transgenic tobacco seeds via the oral route showed a significant increase in IgA-positive plasma cell presence in tunica propria when compared to the control group with no observed adverse effects. Our findings encourage future studies focusing on swine for evaluation of the protective effects of transformed tobacco seeds against E. coli infection.
Evaluation of antigens stability of tobacco seeds as edible vaccine against VTEC strains
International Journal of Health, Animal science and Food safety, 2015
Plants have represent a promising alternative for biopharmaceutical proteins (Ma et al., 2003; Rossi et al., 2014). Many plant based edible vaccines have been shown to be effective in inducing local immune responses ( Rossi et al., 2013). Edible vaccines can activate both mucosal and systemic immunity, as they come in contact with the digestive tract lining. This dual effect would provide first-line defense against pathogens invading through the mucosa. The antigens are released in the intestines are taken up by M cells that are present over the Payer’s patches (in the ileum) and the gut associated lymphoid tissue (GALT). Edible vaccines represent an important worldwide goal for the prevention of the enteric diseases, also in livestock. In particular, the enteric infections are a significant clinical problem in pigs. Verocytotoxic Escherichia (E.) coli strains are responsible for serious enterotoxaemia that causes important economic losses in the pig industry. The production of a va...
Proceedings of the National Academy of Sciences, 2013
Oral feed-based passive immunization can be a promising strategy to prolong maternal lactogenic immunity against postweaning infections. Enterotoxigenic Escherichia coli (ETEC)-caused postweaning diarrhea in piglets is one such infection that may be prevented by oral passive immunization and might avert recurrent economic losses to the pig farming industry. As a proof of principle, we designed anti-ETEC antibodies by fusing variable domains of llama heavy chain-only antibodies (VHHs) against ETEC to the Fc part of a porcine immunoglobulin (IgG or IgA) and expressed them in Arabidopsis thaliana seeds. In this way, four VHH-IgG and four VHH-IgA antibodies were produced to levels of about 3% and 0.2% of seed weight, respectively. Cotransformation of VHH-IgA with the porcine joining chain and secretory component led to the production of light-chain devoid, assembled multivalent dimeric, and secretory IgA-like antibodies. In vitro analysis of all of the antibody-producing seed extracts showed inhibition of bacterial binding to porcine gut villous enterocytes. However, in the piglet feed-challenge experiment, only the piglets receiving feed containing the VHH-IgA-based antibodies (dose 20 mg/d per pig) were protected. Piglets receiving the VHH-IgA-based antibodies in the feed showed a progressive decline in shedding of bacteria, significantly lower immune responses corroborating reduced exposure to the ETEC pathogen, and a significantly higher weight gain compared with the piglets receiving VHH-IgG producing (dose 80 mg/d per pig) or wild-type seeds. These results stress the importance of the antibody format in oral passive immunization and encourage future expression of these antibodies in crop seeds. molecular farming | mucosal immunity | nanobody | enteric infections | antibiotic replacement
Vaccines for preventing enterotoxigenic Escherichia coli infections in farm animals
Vaccine, 1993
Fimbrial vaccines are routinely given parenterally to pregnant cattle, sheep and swine to protect suckling newborn calves, lambs and pigs against enterotoxigenic Escherichia coli (ETEC) infections. Such vaccines are practical and effective because (1) most .fatal ETEC infections in farm animals occur in the early neonatal period when the antibody titres in colostrum and milk are highest, (2) more than 90% of the ETEC in farm animals belong to a small family of fimbrial antigen types; (3)fimbriae consist of good protein antigens on the bacterial surface where the)' are readily accessible to antibody ," (4)fimbriae are requiredJor a critical step (adhesion-colonization) earl)' in the pathogenesis of the disease. ETEC infections continue to be a significant clinical problem in farm animals' in spite of extensive use of fimbriae-based vaccines. Definitive data on the efficacy of the commercial vaccines infield use are not available. The prevailing perception among animal health professionals is that the vaccines are effective, that the problem occurs chiefly among non-vaccinated animals', and that in some herds vaccination moves peak prevalence of disease from the first to the second or third week after birth, when mortality is lower. It has been suggested that extensive use of vaccines will rapidly select for the emergence of novel or previously low prevalence fimbrial antigen types. There is no evidence that this" has happened after a decade of routine vaccine use in the United States. However, there is no active direct surveillance for such emergence. In contrast to the rational development of vaccines to provide passive lacteal protection against ETEC in suckling neonates, comparatively little progress has been made in providing the knowledge required .for development of vaccines to protect a,qainst postweanin9 ETEC infections in swine.
2020
Background: Post-weaning diarrhea (PWD) caused by Escherichia coli is a worldwide economically important disease in pigs, linked with increased mortality and weight loss. F4- and F18-enterotoxigenic E. coli (ETEC) are the most diagnosed causes of PWD. The efficacy of live oral E. coli vaccines has been previously demonstrated on farms with confirmed clinical cases of PWD. However, the impact of vaccination in subclinical cases with mild or not noticeable clinical manifestations needed to be assessed. This study evaluated the effect of an oral dose of a live E. coli bivalent F4/F18 vaccine in nurseries without ongoing clinical PWD outbreaks but with a history of pathogenic E. coli circulating within the herd. Two controlled blinded studies were performed under commercial conditions in a total of 6 European sites. Overall, 1941 vaccinated piglets and 1976 control piglets were enrolled and were monitored for health, growth, and feed conversion rate. Results: No clinical outbreak of ETE...
2013
26 Enterotoxigenic Escherichia coli (ETEC) remain an important cause of neonatal and 27 post-weaning diarrhoea in pigs. In general, neonatal infections can be prevented 28 effectively by passive colostral and lactogenic immunity obtained by vaccination of 29 the sow. In this respect, several maternal vaccines are on the market. These are 30 applied mainly parenterally in the pregnant sow. However at weaning, lactogenic 31 protection disappears. Strains involved in post-weaning diarrhoea mostly express F4 32 or F18 fimbriae. These fimbriae are important virulence factors since they allow the 33 bacteria to bind to specific receptors on small intestinal enterocytes, resulting in 34 colonization and subsequently the secretion of enterotoxins causing diarrhoea. 35 Consequently, an active mucosal immunity, in which the local production of F4-36 and/or F18-specific sIgA plays an important role, is required to protect pigs against 37 post-weaning diarrhoea. This review aims to give an overview of the immunization 38 strategies applied in the pig model to prevent post-weaning diarrhoea caused by F4-39 and/or F18-positive ETEC in pigs. These include the use of oral live and subunit 40 vaccines, encapsulation strategies and parenteral immunization. 41 42 43 44 45 46 47 48 49 50
Veterinarski arhiv
No safe and effective vaccine exists against porcine enterotoxigenic Escherichia coli (ETEC) strains, which are the etiological agents of post-weaning diarrhoea (PWD), economically one of the most significant diseases of swine, which encountered for major productive losses in swine industry worldwide. The current study was designed to evaluate: (1) efficacy of an oral bivalent F4ac+/F18ac+ non-ETEC live vaccine candidate (VACCINE) in stimulating systemic and intestinal cellular immunity in 4-week-old weaned pigs, (2) the onset and duration of protective immunity of weaned pigs against naturally occurring PWD during the period of 6 weeks following weaning, and (3) the dietary supplement potential of zeolite clinoptilolite (CPL), an antimicrobial mineral and/or immunomodulator/ vaccine adjuvant (VACCINE + CPL). The pigs immunized either with the VACCINE or its combination with dietary CPL had significantly increased body weight gain from Day 7 to Day 42 (P<0.05) of the experiment, ...