Background:Salmonella pullorum is one of the most harmful pathogens to avian species.Magnolol and honokiol,natural compounds extracted from Magnolia officinalis,exerts anti-inflammatory,anti-oxidant and antibacterial ...Background:Salmonella pullorum is one of the most harmful pathogens to avian species.Magnolol and honokiol,natural compounds extracted from Magnolia officinalis,exerts anti-inflammatory,anti-oxidant and antibacterial activities.This study was conducted to evaluate the effects of dietary supplemental magnolol and honokiol in broilers infected with S.pullorum.A total of 360 one-day-old broilers were selected and randomly divided into four groups with six replicates:the negative control group(CTL),S.pullorum-infected group(SP),and the S.pulloruminfected group supplemented with 300 mg/kg honokiol(SPH)or magnolol(SPM).Results:The results showed that challenging with S.pullorum impaired growth performance in broilers,as indicated by the observed decreases in body weight(P<0.05)and average daily gains(P<0.05),along with increased spleen(P<0.01)and bursa of Fabricus weights(P<0.05),serum globulin contents,and the decreased intestine villus height and villus/crypt ratios(P<0.05).Notably,supplemental magnolol and honokiol attenuated these adverse changes,and the effects of magnolol were better than those of honokiol.Therefore,we performed RNA-Seq in ileum tissues and 16S rRNA gene sequencing of ileum bacteria.Our analysis revealed that magnolol increased the α-diversity(observed species,Chao1,ACE,and PD whole tree)and β-diversity of the ileum bacteria(P<0.05).In addition,magnolol supplementation increased the abundance of Lactobacillus(P<0.01)and decreased unidentified Cyanobacteria(P<0.05)both at d 14 and d 21.Further study confirmed that differentially expressed genes induced by magnolol and honokiol supplementation enriched in cytokine-cytokine receptor interactions,in the intestinal immune network for IgA production,and in the cell adhesion molecule pathways.Conclusions:Supplemental magnolol and honokiol alleviated S.pullorum-induced impairments in growth performance,and the effect of magnolol was better than that of honokiol,which could be partially due to magnolol’s ability to improve the intestinal microbial and mucosal barrier.展开更多
In this study,a safety enhanced Salmonella Pullorum(S.Pullorum)ghost was constructed using an antimicrobial peptide gene,and evaluated for its potential as a Pullorum disease(PD)vaccine candidate.The antimicrobial pep...In this study,a safety enhanced Salmonella Pullorum(S.Pullorum)ghost was constructed using an antimicrobial peptide gene,and evaluated for its potential as a Pullorum disease(PD)vaccine candidate.The antimicrobial peptide SMAP29 was co-expressed with lysis gene E to generate S.Pullorum ghosts.No viable bacteria were detectable either in the fermentation culture after induction of gene E-and SMAP29-mediated lysis for 24 h or in the lyophilized ghost products.Specific-pathogenfree(SPF)chicks were intraperitoneally immunized with ghosts at day 7 of age and no mortality,clinical symptoms or signs of PD such as anorexia,depression and diarrhea were observed.On challenge with a virulent S.Pullorum strain at 4 wk post-immunization,a comparatively higher level of protection was observed in the S.Pullorum ghost immunized chickens with a minimum of pathological lesions and bacterial loads compared to the birds in inactivated vaccine groups.In addition,immunization with the S.Pullorum ghosts induced a potent systemic Ig G response and was associated with significantly increased levels of cytokine IFN-γand IL-4 and relative percentages of CD4^+ and CD8^+ T lymphocytes.Our results indicate that SMAP29 can be employed as a new secondary lethal protein to enhance the safety of bacterial ghosts,and to prepare a non-living bacterial vaccine candidate that can prevent PD in chickens.展开更多
This study was designed to identify molecular markers single nucieotide polymorphisms(SNPs) of MHC B-F gene and SPOCK1) associated with Salmonella pullorum disease susceptibility/resistance.A two-stage case-control as...This study was designed to identify molecular markers single nucieotide polymorphisms(SNPs) of MHC B-F gene and SPOCK1) associated with Salmonella pullorum disease susceptibility/resistance.A two-stage case-control association study was used.In the first study,a small population comprising 401 Partridge chickens(201 cases and 200 controls)was used,and a total of 118 SNPs genotyped.In the second study,a bigger population comprising 1 075 Partridge chickens(527 cases and 548 controls) was used,and SNPs with significant effect determined in the first study were further analysed.In the first study,8 SNPs were significantly associated with S.Pullorum disease susceptibility/resistance,however,after further analysis,only the SNPs rs15001532 and C.513A>T were found to be significantly associated with S.Pullorum disease susceptibility/resistance.The relative risk test demonstrated that the AA genotype of rs15001532 resulted in a higher risk of S.Pullorum infection,whereas birds with the TT genotype of C.513A>T were more susceptible to S.Pullorum infection.This research was based on the researches on human complex diseases.With help of these train of thoughts,some common animal diseases can be studied effectively and the process of candidate gene research for animal disease can be improved.展开更多
The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticl...The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticles as a marker, covalently conjugate with monoclonal antibodies of Salmonella pullorum. The whole Salmonella pullorum antigen and goat anti-mouse antibody sprayed on the nitrocellulose membranes are used as test line and control line. The fluorescence nanoparticles immune based lateral flow strips are made according to the principle of antigen-antibody immune response. The test strips may interpret results within 30 min. The results of the salmonella A, S. agona, S. chester and S. arechavaleta are positive, including, S. agona for weakly positive. After analysis, it is found that in addition to the salmonella of group A, the other positive salmonella are in group B. But it is negative of S. derby, S. rissen, and other 6 kinds of salmonella, with good specificity. The fluorescence nanoparticles immune based lateral flow strips are a little of sample can be detected fast, easily, inexpensive, easy to universal without professional technical personnel detection method. It provides a new detection method for the detections of Salmonella pullorum.展开更多
为了解crp/cya基因对鸡白痢沙门菌毒力和生物学特性的影响,本研究构建缺失1182 bp cya基因的重组自杀性质粒pREΔcya,并经酶切和测序鉴定正确后,转化大肠杆菌χ7213作为供体菌,分别以鸡白痢沙门菌C79-13株和本研究室前期构建的其crp基...为了解crp/cya基因对鸡白痢沙门菌毒力和生物学特性的影响,本研究构建缺失1182 bp cya基因的重组自杀性质粒pREΔcya,并经酶切和测序鉴定正确后,转化大肠杆菌χ7213作为供体菌,分别以鸡白痢沙门菌C79-13株和本研究室前期构建的其crp基因缺失株C79-13Δcrp(简写为Δcrp)为受体菌,利用重组自杀性质粒介导的同源重组技术构建C79-13菌株的单基因缺失株Δcya以及双基因缺失株ΔcrpΔcya,并均经PCR和测序鉴定。将这3株菌连续传60代后每隔10代分别利用PCR鉴定cya基因缺失的遗传稳定性;利用玻片凝集试验鉴定各菌株的血清型,并鉴定各菌株的生化反应特性;绘制各菌株的生长曲线分析缺失株与亲本株的生长特性;通过微量结晶紫法检测各菌株的生物被膜(BF)形成能力。PCR和测序鉴定结果显示Δcya、ΔcrpΔcya均正确构建,且cya基因缺失均具有稳定的遗传性。血清型及生化鉴定结果显示,菌株Δcya、Δcrp、ΔcrpΔcya均保留了C79-13的O9血清型,而失去了发酵蔗糖、鼠李糖、葡萄糖、麦芽糖等糖类的能力。生长曲线及BF形成能力的检测结果显示,各缺失株的生长速度较亲本株相比均显著降低,尤其双基因缺失株ΔcrpΔcya的生长速度极显著下降(P<0.01),且基因缺失株BF的形成能力均极显著降低(P<0.01),其中双基因缺失株BF的形成能力更低。将3株缺失菌及亲本菌分别以不同的剂量(5×10^(8)cfu/只~7×10^(11)cfu/只)经腹腔注射感染雏鸡进行毒力试验,计算各菌株对雏鸡的半数致死量(LD_(50))。将各缺失株以10^(7) cfu/mL两次经灌服免疫雏鸡,100μL/只,二免后7 d各组雏鸡均以5.0×10^(8)cfu/mL经腹腔注射亲本菌株C79-13进行攻毒试验,500μL/只,在42 d的观察期内观察并记录各组鸡的发病及死亡情况,计算各基因缺失株对雏鸡的免疫保护率。结果显示,缺失株Δcya、Δcrp、ΔcrpΔcya对雏鸡的LD_(50)分别为2.84×10^(9) cfu/mL、1.41×10^(10)cfu/mL、2.51×10^(11)cfu/mL,与亲本菌株C79-13相比,各缺失株LD_(50)分别升高约1.1×10^(3)倍、5.7×10^(3)倍、1.0×10^(5)倍;各组雏鸡攻毒后出现精神沉郁症状,且有部分鸡死亡,PBS对照组鸡出现排稀便症状,且全部死亡。Δcya、Δcrp及ΔcrpΔcya对雏鸡的免疫保护率分别为60%、80%、50%。表明各基因缺失株均能够对雏鸡提供一定的免疫保护效果,且单基因缺失株Δcrp的免疫效果最好。本研究首次对鸡白痢沙门菌crp、cya基因生物学功能做了初步研究,并证实缺失株Δcrp有望作为一种鸡白痢沙门菌基因缺失疫苗的候选菌株,为研制安全有效的沙门菌弱毒活疫苗奠定了基础。展开更多
基金supported by the project of Hubei innovation center of agricultural science and technology(grant number 2016-620-000-001-028)National Natural Science Foundation of China(31702309)the Youth Fund of Hubei Academy of Agricultural Sciences(2019NKYJJ03).
文摘Background:Salmonella pullorum is one of the most harmful pathogens to avian species.Magnolol and honokiol,natural compounds extracted from Magnolia officinalis,exerts anti-inflammatory,anti-oxidant and antibacterial activities.This study was conducted to evaluate the effects of dietary supplemental magnolol and honokiol in broilers infected with S.pullorum.A total of 360 one-day-old broilers were selected and randomly divided into four groups with six replicates:the negative control group(CTL),S.pullorum-infected group(SP),and the S.pulloruminfected group supplemented with 300 mg/kg honokiol(SPH)or magnolol(SPM).Results:The results showed that challenging with S.pullorum impaired growth performance in broilers,as indicated by the observed decreases in body weight(P<0.05)and average daily gains(P<0.05),along with increased spleen(P<0.01)and bursa of Fabricus weights(P<0.05),serum globulin contents,and the decreased intestine villus height and villus/crypt ratios(P<0.05).Notably,supplemental magnolol and honokiol attenuated these adverse changes,and the effects of magnolol were better than those of honokiol.Therefore,we performed RNA-Seq in ileum tissues and 16S rRNA gene sequencing of ileum bacteria.Our analysis revealed that magnolol increased the α-diversity(observed species,Chao1,ACE,and PD whole tree)and β-diversity of the ileum bacteria(P<0.05).In addition,magnolol supplementation increased the abundance of Lactobacillus(P<0.01)and decreased unidentified Cyanobacteria(P<0.05)both at d 14 and d 21.Further study confirmed that differentially expressed genes induced by magnolol and honokiol supplementation enriched in cytokine-cytokine receptor interactions,in the intestinal immune network for IgA production,and in the cell adhesion molecule pathways.Conclusions:Supplemental magnolol and honokiol alleviated S.pullorum-induced impairments in growth performance,and the effect of magnolol was better than that of honokiol,which could be partially due to magnolol’s ability to improve the intestinal microbial and mucosal barrier.
基金supported by grants from the National Key Research and Development Program of China (2016YFD0501608)the National Natural Science Foundation of China (31470893)+1 种基金the Special Fund for Agro-scientific Research in the Public Interest,China (201403054)the National High Technology Research and Development Program of China (2011AA10A210)
文摘In this study,a safety enhanced Salmonella Pullorum(S.Pullorum)ghost was constructed using an antimicrobial peptide gene,and evaluated for its potential as a Pullorum disease(PD)vaccine candidate.The antimicrobial peptide SMAP29 was co-expressed with lysis gene E to generate S.Pullorum ghosts.No viable bacteria were detectable either in the fermentation culture after induction of gene E-and SMAP29-mediated lysis for 24 h or in the lyophilized ghost products.Specific-pathogenfree(SPF)chicks were intraperitoneally immunized with ghosts at day 7 of age and no mortality,clinical symptoms or signs of PD such as anorexia,depression and diarrhea were observed.On challenge with a virulent S.Pullorum strain at 4 wk post-immunization,a comparatively higher level of protection was observed in the S.Pullorum ghost immunized chickens with a minimum of pathological lesions and bacterial loads compared to the birds in inactivated vaccine groups.In addition,immunization with the S.Pullorum ghosts induced a potent systemic Ig G response and was associated with significantly increased levels of cytokine IFN-γand IL-4 and relative percentages of CD4^+ and CD8^+ T lymphocytes.Our results indicate that SMAP29 can be employed as a new secondary lethal protein to enhance the safety of bacterial ghosts,and to prepare a non-living bacterial vaccine candidate that can prevent PD in chickens.
基金supported by the Earmarked Fund for the Modern Agroindustry Technology Research System, China (CARS-41)the National High Technology Research and Development Program of China (2011AA100301)
文摘This study was designed to identify molecular markers single nucieotide polymorphisms(SNPs) of MHC B-F gene and SPOCK1) associated with Salmonella pullorum disease susceptibility/resistance.A two-stage case-control association study was used.In the first study,a small population comprising 401 Partridge chickens(201 cases and 200 controls)was used,and a total of 118 SNPs genotyped.In the second study,a bigger population comprising 1 075 Partridge chickens(527 cases and 548 controls) was used,and SNPs with significant effect determined in the first study were further analysed.In the first study,8 SNPs were significantly associated with S.Pullorum disease susceptibility/resistance,however,after further analysis,only the SNPs rs15001532 and C.513A>T were found to be significantly associated with S.Pullorum disease susceptibility/resistance.The relative risk test demonstrated that the AA genotype of rs15001532 resulted in a higher risk of S.Pullorum infection,whereas birds with the TT genotype of C.513A>T were more susceptible to S.Pullorum infection.This research was based on the researches on human complex diseases.With help of these train of thoughts,some common animal diseases can be studied effectively and the process of candidate gene research for animal disease can be improved.
文摘The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticles as a marker, covalently conjugate with monoclonal antibodies of Salmonella pullorum. The whole Salmonella pullorum antigen and goat anti-mouse antibody sprayed on the nitrocellulose membranes are used as test line and control line. The fluorescence nanoparticles immune based lateral flow strips are made according to the principle of antigen-antibody immune response. The test strips may interpret results within 30 min. The results of the salmonella A, S. agona, S. chester and S. arechavaleta are positive, including, S. agona for weakly positive. After analysis, it is found that in addition to the salmonella of group A, the other positive salmonella are in group B. But it is negative of S. derby, S. rissen, and other 6 kinds of salmonella, with good specificity. The fluorescence nanoparticles immune based lateral flow strips are a little of sample can be detected fast, easily, inexpensive, easy to universal without professional technical personnel detection method. It provides a new detection method for the detections of Salmonella pullorum.
