isolates of P.sojae were obtained from diseased soybean plants in 9 counties of Heilongjiang Province and 1 county of Jilin Province in Northeast of China.11 isolates were classified into 3 races;the rest that could n...isolates of P.sojae were obtained from diseased soybean plants in 9 counties of Heilongjiang Province and 1 county of Jilin Province in Northeast of China.11 isolates were classified into 3 races;the rest that could not be classified due to intermediate reactions were classified into 12 virulence types,suggesting virulence diversity of P.sojae in China.Isolates represented race 1,3 and 8.Race 1 was the most prevalent one,and races 3 and 8 were the first report in China.Our results suggest P.sojae is aboriginal in China.展开更多
Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious dise...Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.展开更多
Escherichia coli O157 : H7 is a foodborne pathogen that poses a major threat to public health. Epidemiologic investigations have identified dairy cows, especially calves, are the principal reservoir of E. coli O157 : ...Escherichia coli O157 : H7 is a foodborne pathogen that poses a major threat to public health. Epidemiologic investigations have identified dairy cows, especially calves, are the principal reservoir of E. coli O157 : H7. In this study, based on the results, E. coli O157 : H7 was the main cause of E. coli disease outbreak in late October, 2015, and more than 90% of newborn calves died of serious diarrhea. Through further experiments, the drug sensitivity and resistance of the strain, the expression of the virulence gene and virulence pathogenicity were studied. E. coli O157 : H7 isolates were resistant to 12 antibiotics including penicillin, tetracycline and ampicillin, and were sensitive to eight antibiotics including cefoperazone, ceftazidime and amikacin. Resistance genes included tetB, strB, aadB, aphA, floR, TEM and virulence genes included stx1, eaeA and hlyA. Using specific pathogen free mice, the result showed that the isolate was pathogenic with a median lethal dose of 7.9×107 CFU · mL-1. This study described the pathogenesis and clinical manifestations of E. coli O157 : H7 infection. These results guided the use of antibiotics in prevent and control of bacterial infections in the future.展开更多
Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this stud...Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this study, an 833 bp hypervariable nucleotide region was identified in VP2 genes of known IBDVs with different virulences through multiple sequence alignment.Moreover, using NEBcutter software analysis, two restriction enzyme sites, SpeⅠ(generating 531 and 302 bp fragments) and StuⅠ(generating 242 and 591 bp fragments) were found presented in very virulent but not attenuated IBDVs. Moreover, the restriction enzyme site SacⅠ(generating 218 and 615 bp fragments) presented in attenuated IBDVs but not very virulent IBDVs. Therefore,a reverse-transcription(RT)-PCR combined with a restriction fragment length polymorphism(RFLP) assay was developed to differentiate attenuated and very virulent IBDVs. The RT-PCR assay was used to confirm 282 IBDV positive samples from 310 suspicious dead chicken samples. The 60 IBDV positive samples were used to evaluate the assay, followed by confirmation via gene sequencing and histopathological examinations of the bursas of Fabricius from chickens infected by these IBDVs. The results showed that 24 viral strains with SpeⅠand StuⅠsites were very virulent, causing severe pathological damage in the bursas of Fabricius, while36 viral strains with the SacⅠsite were attenuated IBDVs, exhibiting only slight pathological damage. The combined RT-PCR and RFLP assay provided a useful approach for differentiating the pathogenic phenotypes of IBDVs.展开更多
The experiment was conducted to inoculate one-day old chicks with March's disease (MD) trivalent and herpesvirus of turkey (HVT) vaccines separately, and then to challenge them with virulent MD virus (vMDV) at the...The experiment was conducted to inoculate one-day old chicks with March's disease (MD) trivalent and herpesvirus of turkey (HVT) vaccines separately, and then to challenge them with virulent MD virus (vMDV) at the age of 15 days. and 5, 25, 45 and 75 days after the challenge with vMDV, comparing with the control-challenged chicks without immunization, to detect the immunoprotetive efficacy and dynamic changes of the inductive activity of interleukin-2(IL-2), expression of IL-2 receptor and proliferative function of T cells in thymus and spleen; the number of ANAE+T, AP+T cells and IgG, IgM, IgA antibody-producing cells in Bursa Fabricius, spleen,thymus, cecal tonsil and Harder gland; as the amount of T cells and IgG, IgM, IgA in peripheral blood as well as the content of IgG, IgM and IgA in the tear, trachea washings, bile and intestinal fluids of the experimental chicks. The experimental results firstly demonstrate that the immunorcgulation of IL-2, and IL-2 receptor, the cellualr and humoral immune responses were significantly enhanced in the central and peripheral immune organs; the local mucosal immune function were markedly amplified in the respiratory and digestive tracts of the immunized-challenged,chicks, which were closely correlated with the immunoprotection against MD; the immune response and immunoprotective effect of the trivalent vaccine-immunized chicks were much better than those of HVT vaccine-immunized chicks:展开更多
The plant pathogen Verticillium dahliae causes severe cotton losses in Uzbekistan. To create cotton varieties that are resistant to the more virulent races of V.dahliae we wanted to determine
基金Natural Science Foundation of Heilongjiang Province(C9912 )
文摘isolates of P.sojae were obtained from diseased soybean plants in 9 counties of Heilongjiang Province and 1 county of Jilin Province in Northeast of China.11 isolates were classified into 3 races;the rest that could not be classified due to intermediate reactions were classified into 12 virulence types,suggesting virulence diversity of P.sojae in China.Isolates represented race 1,3 and 8.Race 1 was the most prevalent one,and races 3 and 8 were the first report in China.Our results suggest P.sojae is aboriginal in China.
文摘Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.
文摘Escherichia coli O157 : H7 is a foodborne pathogen that poses a major threat to public health. Epidemiologic investigations have identified dairy cows, especially calves, are the principal reservoir of E. coli O157 : H7. In this study, based on the results, E. coli O157 : H7 was the main cause of E. coli disease outbreak in late October, 2015, and more than 90% of newborn calves died of serious diarrhea. Through further experiments, the drug sensitivity and resistance of the strain, the expression of the virulence gene and virulence pathogenicity were studied. E. coli O157 : H7 isolates were resistant to 12 antibiotics including penicillin, tetracycline and ampicillin, and were sensitive to eight antibiotics including cefoperazone, ceftazidime and amikacin. Resistance genes included tetB, strB, aadB, aphA, floR, TEM and virulence genes included stx1, eaeA and hlyA. Using specific pathogen free mice, the result showed that the isolate was pathogenic with a median lethal dose of 7.9×107 CFU · mL-1. This study described the pathogenesis and clinical manifestations of E. coli O157 : H7 infection. These results guided the use of antibiotics in prevent and control of bacterial infections in the future.
基金Supported by the National Technology and Research Project of China(2015BAD12B01-4)
文摘Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this study, an 833 bp hypervariable nucleotide region was identified in VP2 genes of known IBDVs with different virulences through multiple sequence alignment.Moreover, using NEBcutter software analysis, two restriction enzyme sites, SpeⅠ(generating 531 and 302 bp fragments) and StuⅠ(generating 242 and 591 bp fragments) were found presented in very virulent but not attenuated IBDVs. Moreover, the restriction enzyme site SacⅠ(generating 218 and 615 bp fragments) presented in attenuated IBDVs but not very virulent IBDVs. Therefore,a reverse-transcription(RT)-PCR combined with a restriction fragment length polymorphism(RFLP) assay was developed to differentiate attenuated and very virulent IBDVs. The RT-PCR assay was used to confirm 282 IBDV positive samples from 310 suspicious dead chicken samples. The 60 IBDV positive samples were used to evaluate the assay, followed by confirmation via gene sequencing and histopathological examinations of the bursas of Fabricius from chickens infected by these IBDVs. The results showed that 24 viral strains with SpeⅠand StuⅠsites were very virulent, causing severe pathological damage in the bursas of Fabricius, while36 viral strains with the SacⅠsite were attenuated IBDVs, exhibiting only slight pathological damage. The combined RT-PCR and RFLP assay provided a useful approach for differentiating the pathogenic phenotypes of IBDVs.
文摘The experiment was conducted to inoculate one-day old chicks with March's disease (MD) trivalent and herpesvirus of turkey (HVT) vaccines separately, and then to challenge them with virulent MD virus (vMDV) at the age of 15 days. and 5, 25, 45 and 75 days after the challenge with vMDV, comparing with the control-challenged chicks without immunization, to detect the immunoprotetive efficacy and dynamic changes of the inductive activity of interleukin-2(IL-2), expression of IL-2 receptor and proliferative function of T cells in thymus and spleen; the number of ANAE+T, AP+T cells and IgG, IgM, IgA antibody-producing cells in Bursa Fabricius, spleen,thymus, cecal tonsil and Harder gland; as the amount of T cells and IgG, IgM, IgA in peripheral blood as well as the content of IgG, IgM and IgA in the tear, trachea washings, bile and intestinal fluids of the experimental chicks. The experimental results firstly demonstrate that the immunorcgulation of IL-2, and IL-2 receptor, the cellualr and humoral immune responses were significantly enhanced in the central and peripheral immune organs; the local mucosal immune function were markedly amplified in the respiratory and digestive tracts of the immunized-challenged,chicks, which were closely correlated with the immunoprotection against MD; the immune response and immunoprotective effect of the trivalent vaccine-immunized chicks were much better than those of HVT vaccine-immunized chicks:
文摘The plant pathogen Verticillium dahliae causes severe cotton losses in Uzbekistan. To create cotton varieties that are resistant to the more virulent races of V.dahliae we wanted to determine
