[Objective]This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method.[Method]Antibodies against infectious bursal dise...[Objective]This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method.[Method]Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory,and the results were comparad^with that using traditional agar diffusion method.[Result]The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion;test strips showed higher detection rate in the deter-mination test of 216 clinical samples,with high specificity,easy preservation,and simple and rapid operation,thereby being more suitable for the monitoring of clinical antibodies.[Conclusion]Test strips could replace the existing serological methods,having great promotion and application value in antibody monitoring.展开更多
Grass carp plays an important role in small-scale aquaculture in Vietnam. However, a severe disease, known in Vietnam as "Red Spot Disease", is causing significant economic loss in grass carp aquaculture. In...Grass carp plays an important role in small-scale aquaculture in Vietnam. However, a severe disease, known in Vietnam as "Red Spot Disease", is causing significant economic loss in grass carp aquaculture. In this study, the tissue samples isolated from the grass carp with Red Spot Disease in Vietnam are investigated and comparied with the control GCHV isolated in China by experimental infection, culture cell infection, serological cross reactivity, and RT-PCR amplification. Infected grass carp exhibits hemorrhage symptoms about 5 days after experimental injection with GCHV-V (Vietnam) strain. The symptoms and lethality induced by the GCHV-V strain are identical to that induced by the Chinese GCHV-9014 strain. The Chinese GCHV-873 strain induces typical cytopathogenic effects in 4 cell lines, such as CIK, CAB, FHM and GCO, from the 6 fish cell lines examined. No cytopathogenic effects are observed in all the 6 examined cell lines, including CAB, FHM, CIK, EPC, CCO and GCO, infected by the GCHV-V strain and GCHV-9014 strain. Immunodiffusion assays demonstrate an obvious cross-reactivity among three GCHV strains. Precipitin lines are clearly observed not only between the anti-GCHV-873 serum and the two strains GCHV-873 and GCHV-9014, but also between the anti-GCHV-873 serum and the GCHV-V strain. GCHV can be detected by immunodiffusion assays after three generations of blind propagations in the cell lines inoculated by GCHV-V strain. This implicates that GCHV-V viruses have been replicated and amplified despite there being no cytopathogenic effects observed in these examined cell lines. Three genome segments of GCHV, including S8, S9 and S10, are amplified by three sets of PCR primers designed according to the segment sequences published recently. The Q8fp and Q8rp primer set specific for genome segment S8 amplifies a 955 bp fragment from the extracted sample of diseased fish with Red Spot Disease, and the fragment size is identical to that amplified by the same primer set from control GCHV-873 strain. Simultaneously, the Q9fp and Q9rp primer set specific for genome segment S9 generates a same 635 bp product, and the Q10fp and Q10rp primer set specific for genome segment S10 produces a same 697 bp fragment from both template samples of diseased fish with Red Spot Disease and control GCHV-873 strain. The RT-PCR amplification and corresponding size comparison data indicate that the three GCHV-V genome segments extracted from the diseased grass carp with Red Spot Disease in Vietnam should be identical to that in control GCHV-873 strain from China. The data confirm that the causative agent of grass carp Red Spot Disease in Vietnam is a virus, and the virus is closely similar to GCHV strain in China.展开更多
Background: Immune protection in newborn calves relies on a combination of the timing,volume and quality of colostrum consumed by the calf after birth.Poor quality colostrum with inadequate immunoglobulin concentratio...Background: Immune protection in newborn calves relies on a combination of the timing,volume and quality of colostrum consumed by the calf after birth.Poor quality colostrum with inadequate immunoglobulin concentration contributes to failed transfer of passive immunity in calves,leading to higher calf morbidity and mortality.Therefore,estimating colostrum quality and ensuring the transfer of passive immunity on farm is of critical importance.Currently,there are no on-farm tools that directly measure immunoglobulin content in colostrum or serum.The aim of this study was to apply a novel molecular assay,split trehalase immunoglobulin G assay(STIGA),to directly estimate immunoglobulin content in dairy and beef colostrum and calf sera,and to examine its potential to be developed as on-farm test.The STIGA is based on a split version of trehalase TreA,an enzyme that converts trehalose into glucose,enabling the use of a common glucometer for signal detection.In a first study,60 dairy and64 beef colostrum and 83 dairy and 84 beef calf sera samples were tested with STIGA,and the resulting glucose production was measured and compared with radial immunodiffusion,the standard method for measuring immunoglobulin concentrations.Results: Pearson correlation coefficients between the methods were determined and the sensitivity,specificity,and accuracy of the test were calculated for different colostrum quality and failed transfer of passive immunity cut-off points.The correlations of the STIGA measured by colorimetric enzymatic reaction compared to radial immunodiffusion for dairy and beef colostrum were 0.72 and 0.73,respectively,whereas the correlations for dairy and beef sera were 0.9 and 0.85,respectively.Next,STIGA was tested in a blinded study with fresh colostrum and serum samples where the correlation coefficient was 0.93 and 0.94,respectively.Furthermore,the performance of STIGA followed by glucometer readings resulted in correlations with radial immunodiffusion of 0.7 and 0.85 for dairy and beef colostrum and 0.94 and 0.83 for dairy and beef calf serum.Conclusions: A split TreA assay was validated for measurement of the immunoglobulin content of colostrum and calf sera using both a lab-based format and in a more user-friendly format compatible with on-farm testing.展开更多
Objective:To explore immunochemical characterization of antigens of Brucella canis(B. canis),and the use in seroprevalence study of canine brucellosis.Methods:External hot phosphate buffer saline extract(HPBSE) and in...Objective:To explore immunochemical characterization of antigens of Brucella canis(B. canis),and the use in seroprevalence study of canine brucellosis.Methods:External hot phosphate buffer saline extract(HPBSE) and internal sonicated(SA) antigens were prepared from B.canis strain MEX 51 and imniunochemically characterized.These antigens were used to test 527 serum samples of dogs by 2-mercaptoethanol-tubc agglutination test(2 ME-TAT), agar gel immunodiffusion test(AGID).dot-ELISA and indirect enzyme-linked immunosorbent assay(I-ELISA) to assess the seroprevalence of canine brucellosis.Results:The protein content of HPBSE and SA antigens was 0.387 mg/ml.and 0.195 mg/mL,respectively,whereas carbohydrate content was 0.174 mg/mL and 0.150 mg/mL,respectively.The sodium dodecyl sulfate-polyacrylamide gel electrophoresis(12.5%) of HPBSE and SA,revealed 6 and 8 visible peptide bands ranging from 18-80 kDa and 12-45 kDa,respectively.Western blot analysis showed immunodominant bands of MW 12.28.39 and 45 kl)a for HPBSE and 20-24 kl)a for SA. The AGII) revealed HPBSE as more specific antigen than SA but both I-ELISA and dot-ELISA indicated SA antigen to be more specific and reliable than HPBSE.The seroprevalence of canine brucellosis was 2.27%by 2ME-TAT.1.5%by AGID.3.03%by dot-ELISA and 16.12%by I-ELISA. Conclusions:On the basis of the results of present study,we concluded that HPBSE is suitable antigen for AGID,which is more specific:whereas SA antigen is suitable for I-ELISA,which is highly sensitive.Therefore,initial screening of serum samples should be carried out by I-ELISA followed by confirmation with AGID.展开更多
IgG Check calf test has been used in this study to identify if a failure of passive transfer occurs in neonatal calves by measuring the level of IgG in blood. An adequate level of IgG measured in all calves at 48 hour...IgG Check calf test has been used in this study to identify if a failure of passive transfer occurs in neonatal calves by measuring the level of IgG in blood. An adequate level of IgG measured in all calves at 48 hours, 7 days and 14 days after birth showed level of IgG 1000 mg/dl. This level indicated that they have good passive transfer of immunity. Also, in this study colostrum quality fed to calves was detected using Brix Refractometer. The colostrum is of high quality as it contains 50 mg/ml of IgG. This Brix refractometer can be used on the farm level to estimate colostrum IgG content and monitoring colostrum feeding practices. Colostrum with high quality IgG could provide calves with enough IgG to attain successful passive transfer of immunity. Brix and Obione refractometers provide simple, rapid method for estimating IgG concentration on calf serum, thus considered to be the most common method for determining passive transfer failure.展开更多
Objective’ Recent studies indicated that incidence of occlusive cardiovascular diseases increased in psoriasis. Changes of serum lipid metabolism may be the cause. Apolipoproteinsplay a central role in lipoprotein me...Objective’ Recent studies indicated that incidence of occlusive cardiovascular diseases increased in psoriasis. Changes of serum lipid metabolism may be the cause. Apolipoproteinsplay a central role in lipoprotein metabolism in serum. The measurement of serum apo levelsmay reveal the characteristics of lipoprotein metabolism in serum in patients with psoriasisand may help to find an answer to the cause of the high incidence of occlusive cardiovasculardiseases in psoriasis.Method. The apo levels of 31 patients with psoriasis vulgaris and 31 sex- and age-matched healthy individuals with normal serum lipid levels were measured by radial immuno-diffusion assay.Results’ The apo C Ⅲ (t= 2.44,P<0. 05) and apo E (t=2. 12, P<0. 05) of psoriat-ic group elevated significantly- The apo C Ⅲ(t= 2.77, P<0.01) of patients less than 40-year-old and apoE (t= 2. 91, P<0. 01) of male patients eIevated significantly. Conclusha. Abndrmal metabolism of lipoprotein in serum exist in psoriasis, especially inmale patients and/or patients less than 40 years old.展开更多
文摘[Objective]This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method.[Method]Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory,and the results were comparad^with that using traditional agar diffusion method.[Result]The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion;test strips showed higher detection rate in the deter-mination test of 216 clinical samples,with high specificity,easy preservation,and simple and rapid operation,thereby being more suitable for the monitoring of clinical antibodies.[Conclusion]Test strips could replace the existing serological methods,having great promotion and application value in antibody monitoring.
基金This research was supported by National 863 High Technology Research Foundation of China(2002AA62601)National Natural Science Foundation of China(30170726)+1 种基金the Project of Chinese Academy of Sciences(KSCXZ-SW-302)the Innovation Project of the Institute of Hydrobiology,Chinese Academy of Sciences.
文摘Grass carp plays an important role in small-scale aquaculture in Vietnam. However, a severe disease, known in Vietnam as "Red Spot Disease", is causing significant economic loss in grass carp aquaculture. In this study, the tissue samples isolated from the grass carp with Red Spot Disease in Vietnam are investigated and comparied with the control GCHV isolated in China by experimental infection, culture cell infection, serological cross reactivity, and RT-PCR amplification. Infected grass carp exhibits hemorrhage symptoms about 5 days after experimental injection with GCHV-V (Vietnam) strain. The symptoms and lethality induced by the GCHV-V strain are identical to that induced by the Chinese GCHV-9014 strain. The Chinese GCHV-873 strain induces typical cytopathogenic effects in 4 cell lines, such as CIK, CAB, FHM and GCO, from the 6 fish cell lines examined. No cytopathogenic effects are observed in all the 6 examined cell lines, including CAB, FHM, CIK, EPC, CCO and GCO, infected by the GCHV-V strain and GCHV-9014 strain. Immunodiffusion assays demonstrate an obvious cross-reactivity among three GCHV strains. Precipitin lines are clearly observed not only between the anti-GCHV-873 serum and the two strains GCHV-873 and GCHV-9014, but also between the anti-GCHV-873 serum and the GCHV-V strain. GCHV can be detected by immunodiffusion assays after three generations of blind propagations in the cell lines inoculated by GCHV-V strain. This implicates that GCHV-V viruses have been replicated and amplified despite there being no cytopathogenic effects observed in these examined cell lines. Three genome segments of GCHV, including S8, S9 and S10, are amplified by three sets of PCR primers designed according to the segment sequences published recently. The Q8fp and Q8rp primer set specific for genome segment S8 amplifies a 955 bp fragment from the extracted sample of diseased fish with Red Spot Disease, and the fragment size is identical to that amplified by the same primer set from control GCHV-873 strain. Simultaneously, the Q9fp and Q9rp primer set specific for genome segment S9 generates a same 635 bp product, and the Q10fp and Q10rp primer set specific for genome segment S10 produces a same 697 bp fragment from both template samples of diseased fish with Red Spot Disease and control GCHV-873 strain. The RT-PCR amplification and corresponding size comparison data indicate that the three GCHV-V genome segments extracted from the diseased grass carp with Red Spot Disease in Vietnam should be identical to that in control GCHV-873 strain from China. The data confirm that the causative agent of grass carp Red Spot Disease in Vietnam is a virus, and the virus is closely similar to GCHV strain in China.
基金Natural Sciences and Engineering Research Council of Canada,Discovery Grant to JDB
文摘Background: Immune protection in newborn calves relies on a combination of the timing,volume and quality of colostrum consumed by the calf after birth.Poor quality colostrum with inadequate immunoglobulin concentration contributes to failed transfer of passive immunity in calves,leading to higher calf morbidity and mortality.Therefore,estimating colostrum quality and ensuring the transfer of passive immunity on farm is of critical importance.Currently,there are no on-farm tools that directly measure immunoglobulin content in colostrum or serum.The aim of this study was to apply a novel molecular assay,split trehalase immunoglobulin G assay(STIGA),to directly estimate immunoglobulin content in dairy and beef colostrum and calf sera,and to examine its potential to be developed as on-farm test.The STIGA is based on a split version of trehalase TreA,an enzyme that converts trehalose into glucose,enabling the use of a common glucometer for signal detection.In a first study,60 dairy and64 beef colostrum and 83 dairy and 84 beef calf sera samples were tested with STIGA,and the resulting glucose production was measured and compared with radial immunodiffusion,the standard method for measuring immunoglobulin concentrations.Results: Pearson correlation coefficients between the methods were determined and the sensitivity,specificity,and accuracy of the test were calculated for different colostrum quality and failed transfer of passive immunity cut-off points.The correlations of the STIGA measured by colorimetric enzymatic reaction compared to radial immunodiffusion for dairy and beef colostrum were 0.72 and 0.73,respectively,whereas the correlations for dairy and beef sera were 0.9 and 0.85,respectively.Next,STIGA was tested in a blinded study with fresh colostrum and serum samples where the correlation coefficient was 0.93 and 0.94,respectively.Furthermore,the performance of STIGA followed by glucometer readings resulted in correlations with radial immunodiffusion of 0.7 and 0.85 for dairy and beef colostrum and 0.94 and 0.83 for dairy and beef calf serum.Conclusions: A split TreA assay was validated for measurement of the immunoglobulin content of colostrum and calf sera using both a lab-based format and in a more user-friendly format compatible with on-farm testing.
基金The financial support provided to the first author in the form of Junior Fellowship by ICAR,New Delhi is duly acknowledged
文摘Objective:To explore immunochemical characterization of antigens of Brucella canis(B. canis),and the use in seroprevalence study of canine brucellosis.Methods:External hot phosphate buffer saline extract(HPBSE) and internal sonicated(SA) antigens were prepared from B.canis strain MEX 51 and imniunochemically characterized.These antigens were used to test 527 serum samples of dogs by 2-mercaptoethanol-tubc agglutination test(2 ME-TAT), agar gel immunodiffusion test(AGID).dot-ELISA and indirect enzyme-linked immunosorbent assay(I-ELISA) to assess the seroprevalence of canine brucellosis.Results:The protein content of HPBSE and SA antigens was 0.387 mg/ml.and 0.195 mg/mL,respectively,whereas carbohydrate content was 0.174 mg/mL and 0.150 mg/mL,respectively.The sodium dodecyl sulfate-polyacrylamide gel electrophoresis(12.5%) of HPBSE and SA,revealed 6 and 8 visible peptide bands ranging from 18-80 kDa and 12-45 kDa,respectively.Western blot analysis showed immunodominant bands of MW 12.28.39 and 45 kl)a for HPBSE and 20-24 kl)a for SA. The AGII) revealed HPBSE as more specific antigen than SA but both I-ELISA and dot-ELISA indicated SA antigen to be more specific and reliable than HPBSE.The seroprevalence of canine brucellosis was 2.27%by 2ME-TAT.1.5%by AGID.3.03%by dot-ELISA and 16.12%by I-ELISA. Conclusions:On the basis of the results of present study,we concluded that HPBSE is suitable antigen for AGID,which is more specific:whereas SA antigen is suitable for I-ELISA,which is highly sensitive.Therefore,initial screening of serum samples should be carried out by I-ELISA followed by confirmation with AGID.
文摘IgG Check calf test has been used in this study to identify if a failure of passive transfer occurs in neonatal calves by measuring the level of IgG in blood. An adequate level of IgG measured in all calves at 48 hours, 7 days and 14 days after birth showed level of IgG 1000 mg/dl. This level indicated that they have good passive transfer of immunity. Also, in this study colostrum quality fed to calves was detected using Brix Refractometer. The colostrum is of high quality as it contains 50 mg/ml of IgG. This Brix refractometer can be used on the farm level to estimate colostrum IgG content and monitoring colostrum feeding practices. Colostrum with high quality IgG could provide calves with enough IgG to attain successful passive transfer of immunity. Brix and Obione refractometers provide simple, rapid method for estimating IgG concentration on calf serum, thus considered to be the most common method for determining passive transfer failure.
文摘Objective’ Recent studies indicated that incidence of occlusive cardiovascular diseases increased in psoriasis. Changes of serum lipid metabolism may be the cause. Apolipoproteinsplay a central role in lipoprotein metabolism in serum. The measurement of serum apo levelsmay reveal the characteristics of lipoprotein metabolism in serum in patients with psoriasisand may help to find an answer to the cause of the high incidence of occlusive cardiovasculardiseases in psoriasis.Method. The apo levels of 31 patients with psoriasis vulgaris and 31 sex- and age-matched healthy individuals with normal serum lipid levels were measured by radial immuno-diffusion assay.Results’ The apo C Ⅲ (t= 2.44,P<0. 05) and apo E (t=2. 12, P<0. 05) of psoriat-ic group elevated significantly- The apo C Ⅲ(t= 2.77, P<0.01) of patients less than 40-year-old and apoE (t= 2. 91, P<0. 01) of male patients eIevated significantly. Conclusha. Abndrmal metabolism of lipoprotein in serum exist in psoriasis, especially inmale patients and/or patients less than 40 years old.
