Background:Enterotoxigenic Escherichia coli(ETEC)F4 commonly colonizes the small intestine and releases enterotoxins that impair the intestinal barrier function and trigger inflammatory responses.Although Bacillus lic...Background:Enterotoxigenic Escherichia coli(ETEC)F4 commonly colonizes the small intestine and releases enterotoxins that impair the intestinal barrier function and trigger inflammatory responses.Although Bacillus licheniformis(B.licheniformis)has been reported to enhance intestinal health,it remains to be seen whether there is a functional role of B.licheniformis in intestinal inflammatory response in intestinal porcine epithelial cell line(IPEC-J2)when stimulated with ETEC F4.Methods:In the present study,the effects of B.licheniformis PF9 on the release of pro-inflammation cytokines,cell integrity and nuclear factor-κB(NF-κB)activation were evaluated in ETEC F4-induced IPEC-J2 cells.Results:B.licheniformis PF9 treatment was capable of remarkably attenuating the expression levels of inflammation cytokines tumor necrosis factor-α(TNF-α),interleukin(IL)-8,and IL-6 during ETEC F4 infection.Furthermore,the gene expression of Toll-like receptor 4(TLR4)-mediated upstream related genes of NF-κB signaling pathway has been significantly inhibited.These changes were accompanied by significantly decreased phosphorylation of p65 NF-κB during ETEC F4 infection with B.licheniformis PF9 treatment.The immunofluorescence and western blotting analysis revealed that B.licheniformis PF9 increased the expression levels of zona occludens 1(ZO-1)and occludin(OCLN)in ETEC F4-infected IPEC-J2 cells.Meanwhile,the B.licheniformis PF9 could alleviate the injury of epithelial barrier function assessed by the trans-epithelial electrical resistance(TEER)and cell permeability assay.Interestingly,B.licheniformis PF9 protect IPEC-J2 cells against ETEC F4 infection by decreasing the gene expressions of virulence-related factors(including luxS,estA,estB,and elt)in ETEC F4.Conclusions:Collectively,our results suggest that B.licheniformis PF9 might reduce inflammation-related cytokines through blocking the NF-κB signaling pathways.Besides,B.licheniformis PF9 displayed a significant role in the enhancement of IPEC-J2 cell integrity.展开更多
Enteric disorders in pigs are related to the fimbriae F4 (K88), F5 (K99), F6 (987P), F41 and F18 of enterotoxigenic Escherichia coli (ETEC). Immunization of sows with adhesins is important to stimulate the production ...Enteric disorders in pigs are related to the fimbriae F4 (K88), F5 (K99), F6 (987P), F41 and F18 of enterotoxigenic Escherichia coli (ETEC). Immunization of sows with adhesins is important to stimulate the production of antibodies and the consequent transfer of these to the piglets via colostrum to prevent diarrhea during the neonate period and after weaning. The objective of this study was to evaluate the immune response of the sows immunized with recombinant ETEC proteins (F4, F5, F6, F18 and F41). The immune response of the sows immunized with the recombinant proteins was compared with a commercial vaccine containing ETEC bacterins. The study was performed on a commercial farm and included nine pregnant sows divided into three groups: G1 was vaccinated with recombinant proteins (n = 3);G2 was vaccinated with the commercial vaccine (n = 3);and G3 was vaccinated with sterile buffered saline (PBS) (n = 3). All the sows were fed a balanced diet without antibiotics and water ad libitum. The recombinant fimbriae stimulated the specific humoral immune response of the immunized sows. There was a statistically significant increase in the levels of antibodies to the fimbriae F4 (K88), F5 (K99), F6 (987P) and F18 in the sows vaccinated with the recombinant proteins compared with the control group. The colostrum IgG titers for all fimbriae in all the immunized sows were significantly increased compared to the control group. Additionally, all the piglets exhibited significantly increased antibody levels relative to all fimbriae when compared with those in the unimmunized control group, demonstrating successful antibody transfer via colostrum of the sows to the piglets.展开更多
Neonatal diarrhea caused by enterotoxigenic Escherichia coli(ETEC)F4 is a common and serious disease,resulting in significant economical loss in the pig industry.The locus encoding ETEC F4 receptor has been mapped to ...Neonatal diarrhea caused by enterotoxigenic Escherichia coli(ETEC)F4 is a common and serious disease,resulting in significant economical loss in the pig industry.The locus encoding ETEC F4 receptor has been mapped to pig chromosome(SSC)13q41,and one of the most significantly linked markers is S0075.In this study,we selected three genes including SLC12A8,MYLK and KPNA1 from a chromosomal region flanking S0075 on SSC13 to develop pig specific sequence tagged sites(STS). Seven single nucleotide polymorphisms were identified in the three pig STS using DNA of four full-sib susceptible and resistant animals in a White Duroc×Erhualian intercross.All grandparents,parents and 755 offspring in the intercross were genotyped for three polymorphisms,including SLC12A8 g.159A>G,MYLK g.1673A>G and KPNA1 g.306A>G.Family-based transmission disequilibrium test(TDT) revealed that all polymorphisms and the corresponding haplotypes are significantly associated with ETEC F4ab/ac(especially F4ac)brush border adhesion phenotypes,indicating that these polymor- phism are in linkage disequlibrium with causal mutation(s)of the gene encoding ETEC F4ab/ac receptor. Our results strengthen the evidence for the involvement of SSC13q41 in high acquiring risk of ETEC F4ab/ac infection,and provide novel polymorphic markers for fine mapping of the ETEC F4ab/ac receptor locus.展开更多
The aim was to evaluate the effects of dietary supplementation of spay-dried whole egg containing antiF4 antibodies(SDWE) against recombinantly produced F4 antigens in enterotoxigenic Escherichia coli K88^+(ETEC)-chal...The aim was to evaluate the effects of dietary supplementation of spay-dried whole egg containing antiF4 antibodies(SDWE) against recombinantly produced F4 antigens in enterotoxigenic Escherichia coli K88^+(ETEC)-challenged piglets. Twenty-seven 21-d-old and individually housed piglets were randomly allotted to 3 treatments consisting of a wheat-soybean meal basal diet containing either 0(control egg powder; CEP), 0.1%(SDWE1) or 0.4%(SDWE2) SDWE. After a 7-d adaptation period, blood samples were collected from all pigs,and pigs were weighed and orally challenged with an ETEC inoculum. Blood was sampled at 24 and 48 h post-challenge, and diarrhea incidences and scores were recorded. On d 14, all pigs were weighed and then euthanized to obtain intestinal tissue samples for histomorphology measurement. During the pre-challenge period, pigs fed the SDWE showed a linear improvement(P < 0.05)in average daily gain(ADG) and gain to feed ratio(G:F), but there were no differences among treatments in growth performance during the post-challenge period. Diarrhea incidences and scores, fecal shedding of ETEC, plasma urea nitrogen content and intestinal histo morphology were similar among treatments.The results show that 0.4% SDWE supported greater piglet performance before challenge although such benefits were not evident during the post-challenge period at either 0.1% or 0.4% supplementation.展开更多
基金supported by the Agriculture and Agri-Food Canada,AAFC’s IOP project,Manitoba Pork and Swine Innovation PorcCanada Foundation for Innovation(CFI)supported by the Chinese Scholarship Council(CSC).
文摘Background:Enterotoxigenic Escherichia coli(ETEC)F4 commonly colonizes the small intestine and releases enterotoxins that impair the intestinal barrier function and trigger inflammatory responses.Although Bacillus licheniformis(B.licheniformis)has been reported to enhance intestinal health,it remains to be seen whether there is a functional role of B.licheniformis in intestinal inflammatory response in intestinal porcine epithelial cell line(IPEC-J2)when stimulated with ETEC F4.Methods:In the present study,the effects of B.licheniformis PF9 on the release of pro-inflammation cytokines,cell integrity and nuclear factor-κB(NF-κB)activation were evaluated in ETEC F4-induced IPEC-J2 cells.Results:B.licheniformis PF9 treatment was capable of remarkably attenuating the expression levels of inflammation cytokines tumor necrosis factor-α(TNF-α),interleukin(IL)-8,and IL-6 during ETEC F4 infection.Furthermore,the gene expression of Toll-like receptor 4(TLR4)-mediated upstream related genes of NF-κB signaling pathway has been significantly inhibited.These changes were accompanied by significantly decreased phosphorylation of p65 NF-κB during ETEC F4 infection with B.licheniformis PF9 treatment.The immunofluorescence and western blotting analysis revealed that B.licheniformis PF9 increased the expression levels of zona occludens 1(ZO-1)and occludin(OCLN)in ETEC F4-infected IPEC-J2 cells.Meanwhile,the B.licheniformis PF9 could alleviate the injury of epithelial barrier function assessed by the trans-epithelial electrical resistance(TEER)and cell permeability assay.Interestingly,B.licheniformis PF9 protect IPEC-J2 cells against ETEC F4 infection by decreasing the gene expressions of virulence-related factors(including luxS,estA,estB,and elt)in ETEC F4.Conclusions:Collectively,our results suggest that B.licheniformis PF9 might reduce inflammation-related cytokines through blocking the NF-κB signaling pathways.Besides,B.licheniformis PF9 displayed a significant role in the enhancement of IPEC-J2 cell integrity.
文摘Enteric disorders in pigs are related to the fimbriae F4 (K88), F5 (K99), F6 (987P), F41 and F18 of enterotoxigenic Escherichia coli (ETEC). Immunization of sows with adhesins is important to stimulate the production of antibodies and the consequent transfer of these to the piglets via colostrum to prevent diarrhea during the neonate period and after weaning. The objective of this study was to evaluate the immune response of the sows immunized with recombinant ETEC proteins (F4, F5, F6, F18 and F41). The immune response of the sows immunized with the recombinant proteins was compared with a commercial vaccine containing ETEC bacterins. The study was performed on a commercial farm and included nine pregnant sows divided into three groups: G1 was vaccinated with recombinant proteins (n = 3);G2 was vaccinated with the commercial vaccine (n = 3);and G3 was vaccinated with sterile buffered saline (PBS) (n = 3). All the sows were fed a balanced diet without antibiotics and water ad libitum. The recombinant fimbriae stimulated the specific humoral immune response of the immunized sows. There was a statistically significant increase in the levels of antibodies to the fimbriae F4 (K88), F5 (K99), F6 (987P) and F18 in the sows vaccinated with the recombinant proteins compared with the control group. The colostrum IgG titers for all fimbriae in all the immunized sows were significantly increased compared to the control group. Additionally, all the piglets exhibited significantly increased antibody levels relative to all fimbriae when compared with those in the unimmunized control group, demonstrating successful antibody transfer via colostrum of the sows to the piglets.
基金National High Technology Research and Development Program of China("863"Program)(Grant No.2006AA10Z194)Jiangxi Provincial KeyResearch Project
文摘Neonatal diarrhea caused by enterotoxigenic Escherichia coli(ETEC)F4 is a common and serious disease,resulting in significant economical loss in the pig industry.The locus encoding ETEC F4 receptor has been mapped to pig chromosome(SSC)13q41,and one of the most significantly linked markers is S0075.In this study,we selected three genes including SLC12A8,MYLK and KPNA1 from a chromosomal region flanking S0075 on SSC13 to develop pig specific sequence tagged sites(STS). Seven single nucleotide polymorphisms were identified in the three pig STS using DNA of four full-sib susceptible and resistant animals in a White Duroc×Erhualian intercross.All grandparents,parents and 755 offspring in the intercross were genotyped for three polymorphisms,including SLC12A8 g.159A>G,MYLK g.1673A>G and KPNA1 g.306A>G.Family-based transmission disequilibrium test(TDT) revealed that all polymorphisms and the corresponding haplotypes are significantly associated with ETEC F4ab/ac(especially F4ac)brush border adhesion phenotypes,indicating that these polymor- phism are in linkage disequlibrium with causal mutation(s)of the gene encoding ETEC F4ab/ac receptor. Our results strengthen the evidence for the involvement of SSC13q41 in high acquiring risk of ETEC F4ab/ac infection,and provide novel polymorphic markers for fine mapping of the ETEC F4ab/ac receptor locus.
基金funded by Natural Sciences and Engineering Research Council of Canada and Zyme Fast System Inc.
文摘The aim was to evaluate the effects of dietary supplementation of spay-dried whole egg containing antiF4 antibodies(SDWE) against recombinantly produced F4 antigens in enterotoxigenic Escherichia coli K88^+(ETEC)-challenged piglets. Twenty-seven 21-d-old and individually housed piglets were randomly allotted to 3 treatments consisting of a wheat-soybean meal basal diet containing either 0(control egg powder; CEP), 0.1%(SDWE1) or 0.4%(SDWE2) SDWE. After a 7-d adaptation period, blood samples were collected from all pigs,and pigs were weighed and orally challenged with an ETEC inoculum. Blood was sampled at 24 and 48 h post-challenge, and diarrhea incidences and scores were recorded. On d 14, all pigs were weighed and then euthanized to obtain intestinal tissue samples for histomorphology measurement. During the pre-challenge period, pigs fed the SDWE showed a linear improvement(P < 0.05)in average daily gain(ADG) and gain to feed ratio(G:F), but there were no differences among treatments in growth performance during the post-challenge period. Diarrhea incidences and scores, fecal shedding of ETEC, plasma urea nitrogen content and intestinal histo morphology were similar among treatments.The results show that 0.4% SDWE supported greater piglet performance before challenge although such benefits were not evident during the post-challenge period at either 0.1% or 0.4% supplementation.
