To investigate the maternal-infantile infection with human parvovirus B19, the IgG and IgM antibodies against human parvovirus and the B19-DNA in serum and peripheral blood mononuclear cells (PBMC) of pregnant women a...To investigate the maternal-infantile infection with human parvovirus B19, the IgG and IgM antibodies against human parvovirus and the B19-DNA in serum and peripheral blood mononuclear cells (PBMC) of pregnant women as well as the serum IgM antibody against B19 and the B19-DNA in serum and cord blood nucleated cells (CBNC) of newborns were determined by ELISA and nested PCR respectively. It was found that the positive rate of the IgG antibody against human parvovirus B19 in sera of 92 pregnant women was 38.04% (35/92), and that of the IgM antibody in 720 pregnant women was 9.03% (65/720). However, the IgM antibody against human parvovirus B19 was negative in the cord blood sera of 95 newborns. As to the human parvovirus B19 DNA, none of 720 pregnant women and 95 newborns was proved to be positive in their sera. Nevertheless, the positive rate of the parvovirus B19 DNA in PBMC was 3.06% (3/98) in 98 pregnant women and 1.12% (1/89) in CBNC of 89 newborns. It is concluded that the history of infection with human parvovirus B19 exists in certain pregnant women with a small percentage of pregnant women infected with recent or acute infections of B19 virus. The detection rates of the B19 viral DNA in PBMC of pregnant women and CBNC of newborns were higher than those in sera, indicating that the risk for vertical transmission is very low.展开更多
Global change,which refers to large-scale changes in the earth system and human society,has been changing the outbreak and transmission mode of many infectious diseases.Climate change affects infectious diseases direc...Global change,which refers to large-scale changes in the earth system and human society,has been changing the outbreak and transmission mode of many infectious diseases.Climate change affects infectious diseases directly and indirectly.Meteorological factors including temperature,precipitation,humidity and radiation influence infectious disease by modulating pathogen,host and transmission pathways.Meteorological disasters such as droughts and floods directly impact the outbreak and transmission of infectious diseases.Climate change indirectly impacts infectious diseases by altering the ecological system,including its underlying surface and vegetation distribution.In addition,anthropogenic activities are a driving force for climate change and an indirect forcing of infectious disease transmission.International travel and rural-urban migration are a root cause of infectious disease transmission.Rapid urbanization along with poor infrastructure and high disease risk in the rural-urban fringe has been changing the pattern of disease outbreaks and mortality.Land use changes,such as agricultural expansion and deforestation,have already changed the transmission of infectious disease.Accelerated air,road and rail transportation development may not only increase the transmission speed of outbreaks,but also enlarge the scope of transmission area.In addition,more frequent trade and other economic activities will also increase the potential risks of disease outbreaks and facilitate the spread of infectious diseases.展开更多
Infectious bursal disease virus(IBDV)causes a highly contagious immunosuppressive disease in chickens,resulting in significant economic losses.The very virulent IBDV strain(vvIBDV)causes high mortality and cannot adap...Infectious bursal disease virus(IBDV)causes a highly contagious immunosuppressive disease in chickens,resulting in significant economic losses.The very virulent IBDV strain(vvIBDV)causes high mortality and cannot adapt to cell culture.In contrast,attenuated strains of IBDV are nonpathogenic to chickens and can replicate in cell culture.Although the crystal structure of T=1 subviral particles(SVP)has been reported,the structures of intact IBDV virions with different virulences remain elusive.Here,we determined the cryo-electron microscopy(cryo-EM)structures of the vvIBDV Gx strain and its attenuated IBDV strain Gt at resolutions of 3.3 Å and 3.2 Å,respectively.Compared with the structure of T=1 SVP,IBDV contains several conserved structural elements unique to the T=13 virion.Notably,the Nterminus of VP2,which is disordered in the SVP,interacts with the S_(F) strand of VP2 from its neighboring trimer,completing theβ-sheet of the S domain.This interaction helps to form a contact network by tethering the adjacent VP2 trimers and contributes to the assembly and stability of the IBDV virion.Structural comparison of the Gx and Gt strains indicates that H253 and T284 in the VP2 P domain of Gt,in contrast to Gx,form a hydrogen bond with a positively charged surface.This suggests that the combined mutations Q253 H/A284 T and the associated structural electrostatic features of the attenuated Gt strain may contribute to adaptation to cell culture.Furthermore,a negatively charged groove in VP2,containing an integrin binding IDA motif that is critical for virus attachment,was speculated to play a functional role in the entry of IBDV.展开更多
基金This work was supported by the Railway Ministry Science and Research Foundation of China (No. J99Z132)
文摘To investigate the maternal-infantile infection with human parvovirus B19, the IgG and IgM antibodies against human parvovirus and the B19-DNA in serum and peripheral blood mononuclear cells (PBMC) of pregnant women as well as the serum IgM antibody against B19 and the B19-DNA in serum and cord blood nucleated cells (CBNC) of newborns were determined by ELISA and nested PCR respectively. It was found that the positive rate of the IgG antibody against human parvovirus B19 in sera of 92 pregnant women was 38.04% (35/92), and that of the IgM antibody in 720 pregnant women was 9.03% (65/720). However, the IgM antibody against human parvovirus B19 was negative in the cord blood sera of 95 newborns. As to the human parvovirus B19 DNA, none of 720 pregnant women and 95 newborns was proved to be positive in their sera. Nevertheless, the positive rate of the parvovirus B19 DNA in PBMC was 3.06% (3/98) in 98 pregnant women and 1.12% (1/89) in CBNC of 89 newborns. It is concluded that the history of infection with human parvovirus B19 exists in certain pregnant women with a small percentage of pregnant women infected with recent or acute infections of B19 virus. The detection rates of the B19 viral DNA in PBMC of pregnant women and CBNC of newborns were higher than those in sera, indicating that the risk for vertical transmission is very low.
基金supported by the National Research Program of the Ministry of Science and Technology,China(Grant Nos.2010CB530300,2012CB955501,2013AA122003&2012AA12A407)the National Natural Science Foundation of China(Grant No.41271099)China Postdoctoral Science Foundation(Grant No.2012M510344)
文摘Global change,which refers to large-scale changes in the earth system and human society,has been changing the outbreak and transmission mode of many infectious diseases.Climate change affects infectious diseases directly and indirectly.Meteorological factors including temperature,precipitation,humidity and radiation influence infectious disease by modulating pathogen,host and transmission pathways.Meteorological disasters such as droughts and floods directly impact the outbreak and transmission of infectious diseases.Climate change indirectly impacts infectious diseases by altering the ecological system,including its underlying surface and vegetation distribution.In addition,anthropogenic activities are a driving force for climate change and an indirect forcing of infectious disease transmission.International travel and rural-urban migration are a root cause of infectious disease transmission.Rapid urbanization along with poor infrastructure and high disease risk in the rural-urban fringe has been changing the pattern of disease outbreaks and mortality.Land use changes,such as agricultural expansion and deforestation,have already changed the transmission of infectious disease.Accelerated air,road and rail transportation development may not only increase the transmission speed of outbreaks,but also enlarge the scope of transmission area.In addition,more frequent trade and other economic activities will also increase the potential risks of disease outbreaks and facilitate the spread of infectious diseases.
基金supported by the National Natural Science Foundation of China(U20A2061,31730023,31521002,32072852)the Chinese Ministry of Science and Technology(2017YFA0504700)+2 种基金the Chinese Academy of Sciences(CAS)(XDB37010100)the State Key Laboratory of Veterinary Biotechnology Foundation(SKLVBF201702)the National Laboratory of Biomacromolecules of China(2020KF12)。
文摘Infectious bursal disease virus(IBDV)causes a highly contagious immunosuppressive disease in chickens,resulting in significant economic losses.The very virulent IBDV strain(vvIBDV)causes high mortality and cannot adapt to cell culture.In contrast,attenuated strains of IBDV are nonpathogenic to chickens and can replicate in cell culture.Although the crystal structure of T=1 subviral particles(SVP)has been reported,the structures of intact IBDV virions with different virulences remain elusive.Here,we determined the cryo-electron microscopy(cryo-EM)structures of the vvIBDV Gx strain and its attenuated IBDV strain Gt at resolutions of 3.3 Å and 3.2 Å,respectively.Compared with the structure of T=1 SVP,IBDV contains several conserved structural elements unique to the T=13 virion.Notably,the Nterminus of VP2,which is disordered in the SVP,interacts with the S_(F) strand of VP2 from its neighboring trimer,completing theβ-sheet of the S domain.This interaction helps to form a contact network by tethering the adjacent VP2 trimers and contributes to the assembly and stability of the IBDV virion.Structural comparison of the Gx and Gt strains indicates that H253 and T284 in the VP2 P domain of Gt,in contrast to Gx,form a hydrogen bond with a positively charged surface.This suggests that the combined mutations Q253 H/A284 T and the associated structural electrostatic features of the attenuated Gt strain may contribute to adaptation to cell culture.Furthermore,a negatively charged groove in VP2,containing an integrin binding IDA motif that is critical for virus attachment,was speculated to play a functional role in the entry of IBDV.