Detection and subtype analysis of VP1 gene of enterovirus 71 strains isolated from children with hand,foot and mouth disease in Shanghai area during the first half year of 2009 / 中华传染病杂志

Objective To understand the characteristics of molecular epidemiology of enterovirus 71(EV71) in children with hand, foot and mouth disease (HFMD) in Shanghai area during the first half year of 2009. Methods Seventy-three throat swabs and 38 stool samples were collected from 95 hospitalized children with clinical diagnosis of HFMD in Children's Hospital of Fudan University during April to May 2009. TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR) and nest RT-PCR were used to detect EV71 VP1, followed by gene sequencing analysis. Results Six of the 73 throat swabs were EV71 positive with the detection rate of 8.2%. In the 38 stool samples, 24 were EV71 positive with the detection rate of 63.2%. Twenty-eight nested RT-PCR positive samples were sequenced and the genetic analysis showed that 27 were C4 subtype,which were absolute dominant strain and the other one was C2 subtype. The isolated strain from a fatal case was C4 subtype and there was no obvious mutation found in VP1 region. Conclusions EV71 is an important pathogen in HFMD children in Shanghai area during April to May 2009. C4 subtype strains are absolutely dominant, and accompanied by epidemic strains of subtype C2.

Cultured cortical astrocytes of newborn rat can be infected by Hantaviruses / 中华传染病杂志

Objective To confirm that astrocytes from cerebral cortex of newborn rat can be the target cells of Hantaan virus (HTNV)and Seoul virus (SEOV)infection and to observe changes of astrocytes after different infection time. Methods Astrocytes were prepared from cerebral cortex of newborn rat, and then infected with HTNV and SEOV. The established virus infections were confirmed by detection of virus nucleocapsid protein (NP) and S segment RNA in astrocytes using double-label immunofluoreseence, Western-blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Results The astrocytes from cerebral cortex of newborn rat were cultured successfully in vitro, which could be infected by HTNV and SEOV. The number of infected astrocytes and the virus titer in the infected astrocytes kept on increasing along with the extended infection duration. Conclusions Astrocytes from cerebral cortex of newborn rat are the target cells for HTNV and SEOV infection. Then establishment of in vitro cultured astrocytes model for Hantaviruses infection will be helpful for the study on the pathogenesis of hemorrhagic fever with renal syndrome.

Detection and identification of human metapneumovirus infection in Shenzhen children / 中华检验医学杂志

Objective To detect human metapneumovirus (hMPV)in respiratory intection rapidly and perform molecular analysis of hMPV.Methods Seven respiratory tract virus(11 subtypes)were assessed using multiplex PCR technology and flexible Multi-Analyte Profiling(suspension array).Human metapneumovirus was confirmed by using a real.Time reverse ranscriptase CR(RT-PCR)assay followed by sequencing.The cladogram analysis was performed further.Results The virus were detected in 40.2%(19/47)samples collected from clinicsl respiratory tract infections,including 8(42.1%)HRSV,7(36.8%)influenza virus,1(5.3%)parainfluenza virus,1(5.3%)rhinovirus,1(5.3%) coxsackievirus and 1(5.3%)human etapneumovirus infections.This is the first time that hMPV was deteced from clinical samples in Shenzhen.The sequencing of specific fragment of neucleoprotein of hMPV showed this hMPV shares over 98% homology with Beijing strain.Japan strain and Thailand strain.The cladogram analysis showed that they were in the same cluste.Conclusions Human etapneumovirus is a maior cause of children respiratory tract disease. Multiplex PCR technology and nexible Multi-Analyte Profiling were hish sensitive and high-throughput for detection of human metapneumovirus.They axe very robust and applicable in etiology analysis.

The establishment of immunochromatographic tests trips with colloidal gold for early and rapid diagnostic of hemorrhagic fever with renal syndrome / 中华检验医学杂志

Objective To establish an early,simple and rapid colloidal gold strip method for the detection of IgM against hantavirus nucleocapsid protein in patients with hemorrhagic fever with renal syndrome(HFRS).Methods Purified recombinant Hantavirus nucleoprotein(rNP)was labeled by colloidal gold particles and then sprayed and fixed on fiberglass membrane as the combination pad.Anti-Human IgM(μ-chain specific)antibody produced in goat was fixed in the detection area,and mouse antihantavirus antibody was fixed in the quality control area.Both of them were on nitrocellous membrane strip in tandem.Together with a specimen pad ahead.The conbination pad and the nitrocellous membrane were assembled into a test strip.The colloidal gold strip assay was compared with ELISA for evaluation of specificity and sensitivity.Results The colloidal gold strip tests showed positive in the serum samples from 50 cases of HFRS which was clinically diagnosed and then verified by ELISA within 10-15 minutes.Whereas 30 serum samples of healthy donors have tested negative.Conclusions Our new colloidal gold immunochromatographic test strip method was well concordant with the ELISA assay,but the former was more raoid and simole.It could be used primary medical services.