BACKGROUNDChina is the most severe endemic area of hemorrhagic fever with renal syndrome (HFRS) in the world with 30,000-50,000 cases reported annually, which accounts for more than 90% of total number of cases worldwide. The incidence rate of the syndrome in Shandong Province is one of the highest in China, which has ever reached 50 per 100,000 persons per year. However, the molecular characteristics of hantaviruses (HV) epidemic in Shandong Province remain unclear. Therefore it is useful to clarify nucleotide sequence and phylogenetic characteristics of HV isolated in Shandong Province in order to provide better advices to control and prevent HFRS.

METHODSRNAs were extracted from sera of clinically diagnosed patients and positive rodent lungs that were detected by indirect immunofluorescent assay (IFA). Partial M segments of HV were amplified from the RNAs with reverse transcription nested polymerase chain reactions (nested PCR) using hantavirus genotype specific primers. The nested PCR products were sequenced and compared with those from previously epidemic isolates in Shandong and with other representative HV sequences from GenBank. Phylogenetic tree analyses were performed based on the sequences of the M genes.

RESULTSThirty-four HV isolates in Shandong showed 67.1%-100% nucleotide identities. The nucleotide homologies among 6 Hantaan viruses (HTNV) isolates in Shandong were 78.1%-98.7%, while the homologies among 28 Seoul virus (SEOV) isolates in Shandong were 93.7%-100%. There were at least 3 subtypes HTNV (H2, H5, H9) and 2 subtypes SEOV (S2, S3) in Shandong Province.

CONCLUSIONSIn Shandong Province, the homologies of HTNV were lower and there were no predominant subtypes, while the homologies of SEOV were higher and S3 was the predominant subtype. The homologies of SEOV from rodents were higher than those from patients. The distribution of subtypes in Shandong was similar to that of the adjoining provinces. Phylogenetic analyses of the sequences showed geographic clustering of HV in Shandong.

Animals ; Antigens, Viral ; analysis ; Base Sequence ; Genetic Variation ; Hantavirus ; classification ; genetics ; Humans ; Lung ; virology ; Phylogeny ; RNA, Viral ; analysis ; Rodentia ; virology

This experiment was performed to determine whether cultured rabbit corneal cells were infected with HSV-1. The direct immunofluorescent method was used to detect the presence of the herpes simplex antigen in HSV-1 infected corneal epithelial cells, keratocytes, and endothelial cells in vitro with fluorescein-labeled antiserum to HSV-1. Immunofluorescent localization of the HSV-1 antigen was expressed in all three types of corneal cells.
Animals ; Antigens, Viral/*analysis ; Cells, Cultured ; Cornea/*microbiology ; Herpesviridae Infections/*microbiology ; Rabbits ; Simplexvirus/*immunology

OBJECTIVETo investigate the viral contamination of invasive medical instruments in dentistry and to provide health administrative institutions with surveillance data.

METHODSSterilized samples were randomly collected from the department of dentistry to detect HBV-DNA, HCV-RNA, HIV-RNA and HBsAg.

RESULTSOf the invasive medical instruments that were sterilized with 2% glutaraldehyde, one of the samples was positive for HBV-DNA, and another sample was positive for HBsAg.

CONCLUSIONThough massive virus contamination of invasive medical instruments in dentistry has been reduced to a low level, the occurrence of contamination still remains.

DNA, Viral ; analysis ; Dental Instruments ; virology ; Equipment Contamination ; HIV ; isolation & purification ; Hepacivirus ; isolation & purification ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B virus ; isolation & purification ; Humans ; RNA, Viral ; analysis

BACKGROUNDSeveral coronaviruses establish persistent infections in vitro and in vivo, however it is unknown whether persistence is a feature of the severe acute respiratory syndrome coronavirus (SARS-CoV) life cycle. This study was conducted to investigate viral persistence.

METHODSWe inoculated confluent monolayers of Vero cells with SARS-CoV at a multiplicity of infection of 0.1 TCID50 and passaged the remaining cells every 4 to 8 days for a total of 11 passages. Virus was titrated at each passage by limited dilution assay and nucleocapsid antigen was detected by Western blot and immunofluoresence assays. The presence of viral particles in passage 11 cells was assessed by electron microscopy. Changes in viral genomic sequences during persistent infection were examined by DNA sequencing.

RESULTSCytopathic effect was extensive after initial inoculation but diminished with serial passages. Infectious virus was detected after each passage and viral growth curves were identical for parental virus stock and virus obtained from passage 11 cells. Nucleocapsid antigen was detected in the majority of cells after initial inoculation but in only 10%-40% of cells at passages 2-11. Electron microscopy confirmed the presence of viral particles in passage 11 cells. Sequence analysis at passage 11 revealed fixed mutations in the spike (S) gene and ORFs 7a-8b but not in the nucleocapsid (N) gene.

CONCLUSIONSSARS-CoV can establish a persistent infection in vitro. The mechanism for viral persistence is consistent with the formation of a carrier culture whereby a limited number of cells are infected with each round of virus replication and release. Persistence is associated with selected mutations in the SARS-CoV genome. This model may provide insight into SARS-related lung pathology and mechanisms by which humans and animals can serve as reservoirs for infection.

Animals ; Antigens, Viral ; analysis ; Cercopithecus aethiops ; Microscopy, Electron ; Nucleocapsid Proteins ; analysis ; SARS Virus ; genetics ; growth & development ; Vero Cells

OBJECTIVETo investigate hepatitis E virus (HEV) infection among pigs in Henan province.

METHODSA total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively. The sera positive for HEV antigen were tested for HEV RNA with RT-PCR. The positive products of RT-PCR were cloned and sequenced.

RESULTSThe positive rates of anti-HEV antibody of the groups under 3-month and over 3-month of age were 90.27% and 92.55%, respectively, without statistical difference, while those of HEV antigen were 15.93% and 5.69%, respectively, with significant difference. The positive rates of anti-HEV antibody and HEV antigen were significantly different among different districts. HEV RNA was detectable in 5 of 47 HEV antigen positive samples. The sequence analysis showed that in 4 of 5 specimens the sequence belonged to genotype 4 while in the remaining one the sequence was genotype 1.

CONCLUSIONThe prevalence rate of HEV infection in pigs was high in Henan province and the rate differed in different districts.

Animals ; Antibodies, Viral ; analysis ; immunology ; Antigens, Viral ; analysis ; immunology ; China ; Genotype ; Hepatitis E ; epidemiology ; immunology ; veterinary ; virology ; Hepatitis E virus ; genetics ; immunology ; isolation & purification ; Phylogeny ; RNA, Viral ; analysis ; genetics ; Sequence Analysis, DNA ; Swine ; virology ; Swine Diseases ; epidemiology ; immunology ; virology

OBJECTIVETo quantitatively detect intrahepatic HBV covalently closed circular DNA (cccDNA) and serum HBsAg; and to analyze the relationship between the two parameters and with serum HBV DNA level.

METHODSIntrahepatic cccDNA (copies/cell) was quantitated by plasmid-safe ATP-dependent Danes (PSAD) digestion in combination with rolling circle amplification and gap-spanning selective real-time PCR assay using formalin fixed paraffin-embedded liver biopsy samples. HBsAg was measured by chemiluminescence's reagent manufactured by Abbott Company using sera sampled at time-point of liver biopsy.

RESULTSIntrahepatic cccDNA level was positively correlated with serum HBsAg level (r = 0.459, P < 0.001), but not correlated with serum HBV DNA level. Serum HBsAg level was positively correlated with serum HBV DNA level (r = 0.328, P = 0.015), and reversely correlated with HBV replicative efficiency defined as the ratio of serum HBV DNA to cccDNA (r = -0.373, P = 0.005).

CONCLUSIONIn patients with chronic hepatitis B, intrahepatic cccDNA level is correlated with serum HBsAg level. The two parameters combined with serum HBV DNA may comprehensively reflect HBV replication activity and help evaluation of antiviral therapeutic efficacy.

DNA, Circular ; analysis ; DNA, Viral ; analysis ; Female ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; blood ; virology ; Humans ; Liver ; virology ; Male ; Viral Load

OBJECTIVETo better understand the duplication of hepatitis B virus (HBV) in order to improve clinical diagnoses and treatments via quantitative measurement of HBV-DNA and comparison of correlation of HBV-DNA with HBeAg and anti-HBe.

METHODSFor 883 hepatitis B patients with positive HBsAg, HBV-DNA was measured by COBAS AMPLICOR HBV MONITOR reagent and COBAS AMPLICOR quantitative PCR instrument. Microparticle enzyme immunoassay analysis (MEIA) was then carried out with fully automatic enzyme immunoassay analysis instrument made by Abbott Axsym from the U.S. to measure HBeAg and anti-HBe. Correlation was analysed by SPSS.

RESULTS(1)Positive correlation between 690 HBV-DNA positive and HBeAg positive with r= 0. 505 (P< 0.01) was found with mean values as:HBV-DNA:7.12 x 10(12) copies/ml;HBeAg:218.31 S/CO. HBV-DNA:10(4) copies/ml, HBeAg: 104 S/CO; HBV-DNA: 10(5)-10(8) copies/ml, HBeAg: 112 S/CO; HBV-DNA: 10(9)-10(15) copies/ml, HBeAg: 252 S/CO. (2) No correlation was found between 193 HBV-DNA and anti-HBe + with r= -0.052(P= 0.477> 0.05) with Mean: HBV-DNA: 8.0x 10(10) copies/ml anti-HBe: 0.18 S/CO.

CONCLUSIONHBV-DNA and HBeAg appeared to have had linear correlation, showing that HBeAg> 100 S/CO,HBV-DNA> 10(4) copies/ml and hepatitis B virus were reproduced. However, HBV-DNA did not show linear correlation with anti-HBe as HBeAg negative and anti-HBe positive, the level of hepatitis B viral replication decrease slightly. But the virus load is still high. Infectivity can not neglect.

Antibodies, Viral ; analysis ; Carrier State ; DNA, Viral ; analysis ; Hepatitis B ; diagnosis ; genetics ; immunology ; Hepatitis B e Antigens ; analysis ; Hepatitis B virus ; genetics ; immunology ; Humans ; Immunoenzyme Techniques ; Polymerase Chain Reaction ; Viral Load ; Virus Replication

BACKGROUNDTo clarify the features of gene variation among epidemic strains of human rotavirus NSP4 in China.

METHODSSP4 genes from 27 epidemic strains of human rotavirus isolated in different area of China in recent years were amplified with RT-PCR, the resulted cDNAs were cloned and sequenced. The sequences of full length cDNAs were compared with 10 rotavirus NSP4 sequences available in the GenBank using the Clustal x 1.8 TreeView32 and DNA Star softwares. The G serotype of VP7 was analysed by PCR.

RESULTSThe homology of the amino acid among the 27 rotavirus strains isolated in China was 81.7%-99.4%. Based on the variation of amino acid sequence, the virus strains can be divided into two groups, represented by Wa and KUN with the homology of 92.0%-99.4% and 92.0%-98.9% within each group, respectively. The diversity between the two groups were 16.6%-21.0%. The Wa group could further be separated into three subgroups, according to the diversity between those strains and the characterization in the highly variable domain. The association between VP7 serotype and NSP4 genotype was not strong.

CONCLUSIONSThe NSP4 gene of human rotavirus epidemic strains in China can be divided into Wa and KUN two groups, Wa group is the main group and contains three subgroups possessing characteristic amino acid sites. Samples isolated in the same year but not in the same area shared higher homology.

Antigens, Viral ; Capsid Proteins ; genetics ; DNA, Complementary ; analysis ; DNA, Viral ; analysis ; Diarrhea ; virology ; Genetic Variation ; Genotype ; Glycoproteins ; genetics ; Humans ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus ; genetics ; isolation & purification ; Sequence Analysis, DNA ; Toxins, Biological ; Viral Nonstructural Proteins ; genetics

OBJECTIVETo establish an in vitro model of hepatitis B virus (HBV) replication and expression in primary rat hepatocytes (PRH) transfected with circular viral DNA for further study on the interaction of HBV with hepatocytes.

METHODSCircular viral DNA containing complete HBV genome were transfected into PRH by electroporation (transfected group, about 4mug of circular viral DNA/1 10(7)cells). From day 1 to day 10 after transfection, HBsAg and HBeAg in the supernatants and lysates of PRH were measured with IMX system. HBcAg was assayed with western blotting, immunol dot blotting and immunocytochemistry. Meanwhile, HBV S-mRNA and X-mRNA were tested with RT-PCR, and replicative intermediates of HBV DNA were analyzed by southern blotting and dot blotting. Moreover, Transmission electron microscopy was used if viral particles were produced in transfected rat hepatocytes. PRH electroporated only was used as control group.

RESULTS(1) Viral antigen production in transfected rat hepatocytes: HBsAg in cell lysates was positive. P/N values ranged from 4.83 to 85.69, and could be maintained for 10 days after transfection. The average P/N values was 18.239 27.459. Whereas, HBsAg was negative in the supernatants of transfected group (P/N values, negative<2.1). HBeAg in the supernatants and lysates of transfected hepatocytes all was negative (P/N values<2.1) during 10 days following transfection. HBcAg was only found positive in transfected hepatocytes by immunol dot blotting. (2) Detection of viral transcripts: transcription of HBV DNA was investigated by preparing total RNA from rat hepatocytes 2 days after transfection and looking for S-mRNA and X-mRNA by RT-PCR. Results showed S-mRNA positive, X-mRNA negative. (3) HBV DNA replication analysis: intracellular total DNA was extracted 2 days after transfection and analysed by southern blotting. All replicative DNA intermediates, including relaxed circular (rcDNA), covalently closed circular (cccDNA), and single-stranded (ssDNA) linear HBV DNA forms, were indicated. Dot blotting showed intracellular HBV DNA positive in transfected group during 10 days after transfection. However, viral particles were not found in transfected hepatocytes during 3 days after transfection.

CONCLUSIONSCircular HBV DNA transfected into primary adult rat hepatocytes could obtain continuous replication and stable expression of HBV surface antigen. This in vitro model has high reproducibility and stability, and is useful for directly studying the interaction of HBV with hepatocytes.

Animals ; DNA Replication ; DNA, Circular ; genetics ; DNA, Viral ; genetics ; Gene Expression ; Hepatitis B Core Antigens ; analysis ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B e Antigens ; analysis ; Hepatitis B virus ; genetics ; Hepatocytes ; virology ; Male ; Rats ; Rats, Wistar ; Transfection ; Virus Replication

To evaluate the inhibitory effects of long antisense RNA on HBV replication in HepG2.2.15 cells. The coding region of HBV S gene was cloned into pTARGET vector in sense and antisense orientations and the recombinant plasmids were transfected into HepG2.2.15 cells which were divided into HBS2 (antisense RNA) group, HBS4 (sense RNA) group and control group. HBsAg and HBeAg in the culture supernate were detected by ELISA. The HBV DNA in the supernate was quantified by real-time PCR. After treatment, the levels of HBsAg in HepG2.2.15 cell supernatants of three groups were 0.621+/-0.027, 3.399+/-0.018 and 2.232+/-0.187 respectively; the levels of HBeAg were 0.749+/-0.019, 1.548+/-0.025 and 1.570+/-0.044 respectively and the levels of HBV DNA were 1.597+/-0.082, 3.381+/-0.297 and 3.610+/-0.063 respectively. The expressions of HBsAg and HBeAg and the HBV DNA level in HBS2 group were remarkably reduced as compared to the control (Z = -2.309, P value is less than 0.05); whereas the sense plasmid transfection (HBS4) did not affect HBeAg (Z = -0.866) and HBV DNA (Z = -1.155) levels in the culture supernate but slightly increased the HBsAg level (Z = -2.309). Antisense RNA might be a useful tool to repress HBV replication.
DNA, Viral ; genetics ; Gene Expression Regulation, Viral ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B e Antigens ; analysis ; Hepatitis B virus ; genetics ; physiology ; Humans ; Plasmids ; RNA Interference ; Transfection ; Virus Replication ; genetics