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 antim...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-pathogen- free （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 IgG response and was associated with significantly increased levels of cytokine IFN-y and 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
To test if stabilizing Ampicillin trihydrate (AT) with Aluminium-Magnesium Silicate (AMS) can enhance its antibacterial activities, different concentrations of AT solution and of a formulation of AT in the AMS, were m...To test if stabilizing Ampicillin trihydrate (AT) with Aluminium-Magnesium Silicate (AMS) can enhance its antibacterial activities, different concentrations of AT solution and of a formulation of AT in the AMS, were made and used for sensitivity test on Salmonella gallinarum cultures. Also, S. gallinarum-infected chicks were treated with;10 mg/Kg (AT), 10 mg/Kg (AT in AMS), 7.5 mg/Kg (AT), 7.5 mg/Kg (AT in AMS). Mean diameter of inhibition zone, 28.39 ± 2.07 mm produced by AT did not vary significantly (P > 0.05) from 26.36 ± 2.05 mm produced by AT in AMS. However, mean Salmonella gallinarum culture forming units per ml of bile, 17.6 ± 11 × 105of the untreated chicks and 3.4 ± 0.81 × 105(80.58% reduction), 2.4 ± 0.67 × 105(85.70% reduction), 5.4 ± 1.93 × 105(69.20% reduction ) and 0.38 ± 0.13 × 105(97.80% reduction ) of the respective treated groups, showed AMS significantly (P S. gallinarum infection, in vivo.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
Salmonella gallinarum has shown multiple drug resistance(MDR),especially high level fluoroquinolone(FQ)resistance in recent years.To determine whether the active efflux system was responsible for high-level FQ resista...Salmonella gallinarum has shown multiple drug resistance(MDR),especially high level fluoroquinolone(FQ)resistance in recent years.To determine whether the active efflux system was responsible for high-level FQ resistance,this research studied AcrAB efflux pump in Salmonella gallinarum on molecular level.The resistant strains were induced by standard strain C79-13 with ciprofloxacin in vitro.With carbonylcyanide-p-chlorophenyl hydrazone(CCCP)as an energy inhibitor,efflux inhibition test initially showed the potential impact of efflux pump on drug resistance.Sequence analysis of acrA gene indicated that gene mutation of AcrAB efflux pump was not definitely associated with MDR and drug resistance level of Salmonella gallinarum.Detected by competitive RT-PCR,the mRNA expression of acrA and acrB genes in the resistant strains significantly increased(p<0.01)compared with that of the control strain C79-13.The mRNA expression level of acrB gene(increased from 1.6-to 2.9-folds)was consistent with that of acrA gene(increased from 1.6-to 2.8-folds),which increased with the drug resistance level.However,gene mutation of acrA gene showed no correlation with its mRNA expression level,indicating that gene mutation did not affect the expression of AcrAB pump itself.The results suggested that the overexpression rather than the gene mutation of AcrAB efflux pump was an important factor causing the high level drug resistance of Salmonella gallinarum.展开更多
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）
为了分离一株裂解性鸡白痢沙门氏菌噬菌体,对抗多重耐药细菌,试验从健康鸡粪便中分离富集噬菌体,采用双层琼脂平板法纯化、增殖,超速离心法浓缩,利用透射电镜观察噬菌体形态,通过提取噬菌体基因组、酶切、电泳确定核酸类型,同时测定噬...为了分离一株裂解性鸡白痢沙门氏菌噬菌体,对抗多重耐药细菌,试验从健康鸡粪便中分离富集噬菌体,采用双层琼脂平板法纯化、增殖,超速离心法浓缩,利用透射电镜观察噬菌体形态,通过提取噬菌体基因组、酶切、电泳确定核酸类型,同时测定噬菌体的宿主谱、最佳感染复数、一步生长曲线、酸碱及热稳定性等生物学特性。结果表明:从鸡粪中分离得到1株裂解性噬菌体,命名为PSP2-22。该噬菌体头部直径为(60±5)nm,尾部长为(130±5)nm,为长尾噬菌体科;核酸类型为双链DNA。该噬菌体不仅能裂解鸡白痢沙门氏菌,还可裂解鼠伤寒沙门氏菌和奇异变形杆菌;最佳感染复数为0.1;平均裂解量约为136 pfu/cell,效价最高可达9.83 lg pfu/mL;在pH值6~11时相对稳定,70℃作用60 min之后仍具有一定活性。说明噬菌体PSP2-22是一株对不同温度和pH值有较强适应能力的双链DNA噬菌体,宿主谱相对较宽,具有潜在的应用价值。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-pathogen- free （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 IgG response and was associated with significantly increased levels of cytokine IFN-y and 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.
文摘To test if stabilizing Ampicillin trihydrate (AT) with Aluminium-Magnesium Silicate (AMS) can enhance its antibacterial activities, different concentrations of AT solution and of a formulation of AT in the AMS, were made and used for sensitivity test on Salmonella gallinarum cultures. Also, S. gallinarum-infected chicks were treated with;10 mg/Kg (AT), 10 mg/Kg (AT in AMS), 7.5 mg/Kg (AT), 7.5 mg/Kg (AT in AMS). Mean diameter of inhibition zone, 28.39 ± 2.07 mm produced by AT did not vary significantly (P > 0.05) from 26.36 ± 2.05 mm produced by AT in AMS. However, mean Salmonella gallinarum culture forming units per ml of bile, 17.6 ± 11 × 105of the untreated chicks and 3.4 ± 0.81 × 105(80.58% reduction), 2.4 ± 0.67 × 105(85.70% reduction), 5.4 ± 1.93 × 105(69.20% reduction ) and 0.38 ± 0.13 × 105(97.80% reduction ) of the respective treated groups, showed AMS significantly (P S. gallinarum infection, in vivo.
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.
基金Supported by the Application Technology Research and Development Project in Heilongjiang Province of China(PC13S03)the Foundation of Heilongjiang Province Educational Committee of China(11541030)。
文摘Salmonella gallinarum has shown multiple drug resistance(MDR),especially high level fluoroquinolone(FQ)resistance in recent years.To determine whether the active efflux system was responsible for high-level FQ resistance,this research studied AcrAB efflux pump in Salmonella gallinarum on molecular level.The resistant strains were induced by standard strain C79-13 with ciprofloxacin in vitro.With carbonylcyanide-p-chlorophenyl hydrazone(CCCP)as an energy inhibitor,efflux inhibition test initially showed the potential impact of efflux pump on drug resistance.Sequence analysis of acrA gene indicated that gene mutation of AcrAB efflux pump was not definitely associated with MDR and drug resistance level of Salmonella gallinarum.Detected by competitive RT-PCR,the mRNA expression of acrA and acrB genes in the resistant strains significantly increased(p<0.01)compared with that of the control strain C79-13.The mRNA expression level of acrB gene(increased from 1.6-to 2.9-folds)was consistent with that of acrA gene(increased from 1.6-to 2.8-folds),which increased with the drug resistance level.However,gene mutation of acrA gene showed no correlation with its mRNA expression level,indicating that gene mutation did not affect the expression of AcrAB pump itself.The results suggested that the overexpression rather than the gene mutation of AcrAB efflux pump was an important factor causing the high level drug resistance of Salmonella gallinarum.
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）
文摘为了分离一株裂解性鸡白痢沙门氏菌噬菌体,对抗多重耐药细菌,试验从健康鸡粪便中分离富集噬菌体,采用双层琼脂平板法纯化、增殖,超速离心法浓缩,利用透射电镜观察噬菌体形态,通过提取噬菌体基因组、酶切、电泳确定核酸类型,同时测定噬菌体的宿主谱、最佳感染复数、一步生长曲线、酸碱及热稳定性等生物学特性。结果表明:从鸡粪中分离得到1株裂解性噬菌体,命名为PSP2-22。该噬菌体头部直径为(60±5)nm,尾部长为(130±5)nm,为长尾噬菌体科;核酸类型为双链DNA。该噬菌体不仅能裂解鸡白痢沙门氏菌,还可裂解鼠伤寒沙门氏菌和奇异变形杆菌;最佳感染复数为0.1;平均裂解量约为136 pfu/cell,效价最高可达9.83 lg pfu/mL;在pH值6~11时相对稳定,70℃作用60 min之后仍具有一定活性。说明噬菌体PSP2-22是一株对不同温度和pH值有较强适应能力的双链DNA噬菌体,宿主谱相对较宽,具有潜在的应用价值。
