Bing du xue bao = Chinese journal of virology最新文献

The bat circovirus has been detected from different bat species and regions after detection in Rousettus leschenaultia. To enrich the epidemiologic data of the bat circovirus, a complete sequence named "BtCV-DS13" was obtained by nested polymerase chain reaction and Genome Walking? based on the intestines of Myotis davidii from Zhoushan Island (Zhejiang Province, China). The complete length of BtCV-DS13 was 1873nt, and it had the typical gene structure of a circovirus according to sequencing analyses. The nucleotide sequence identity was 22. 9%, 53. 5%, 24. 7% and 4. 5% for bat 1, bat 2, bat 3, and a bat infected with the cyclovirus, respectively. Phylogenetic analyses based on the full-length sequence strongly supports the suggestion that BtCV-DS13, the bat circovirus, and porcine circovirus should be clustered into the genus Circovirus. These results imply that BtCV-DS13 should be a new bat circovirus.

Emerging and re-emerging zoonotic diseases caused by pathogens such as Middle East respiratory syndrome coronavirus (MERS-CoV), West Nile virus (WNV) or Chikungunya virus (CHIKV) pose considerable threats to public health worldwide. Research on the mechanism of cross-species infection and transmission for animal-origin emerging and re-emerging zoonosis (2016YFD0500300) has won support by the National Key Research and Development Program of China. Professor Wenjie Tan (National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention) was the primary principal investigator of this research group. Focusing on the mechanism of transmission and infection for emerging and re-emerging zoonosis, this research will provide an important. foundation for the prevention and control of zoonosis.

The aim of this study was to explore the influence of mutation of different non-structural (NS) 1 amino-acid residues on the pathogenicity of influenza viruses and the function of NS1 virulence-related sites on the pathogenesis of influenza viruses. We analyzed segments of the NS1 protein gene and key sites related to virulence of influenza viruses based on a literature review. Fragments of the NS1 gene were cloned from the HIN1 subtype PR8F (non-mutated) and preserved by our research team with encoding sequence site-specific mutagenesis at aa42, aa8l, and aa149. Via a reverse genetics system, we rescued the mutant strains PR8F-42, PR8F-81, and PR8F-149, which were inoculated into chick embryos and could replicate stably after five passages. Efficiency of viral replication was measured by testing hemagglutination titers. BALB/c mice were inoculated With mutated or non-mutated PR8F (10(6) TCIDO(50)/100 μl for each mouse), respectively. The typical clinical manifestations (weight change and survival) were recorded. Autopsies, as well as observations of the pathologic features and pulmonary-tissue slices of mice that died after inoculation, were done. RNA of mouse lungs was extracted, and the residual quantity of virus in lungs was detected by quantitative polymerase chain reaction (qPCR). Results showed that mutation of NS1 at aa42 from Ser to Pro did not change the pathogenicity of PR8F in mice, but a low pathogenicity of PR8F occurred after mutation of NS1 at aa8l and aa149. The present study lays the foundation for further investigations of the function of NS1 pathogenicity-related sites in the pathogenesis of influenza viruses.

We wished to identify the existing HCV genotypes in diagnosed cases of infection by the hepatitis C virus in Hohhot (China) to offer basic data for the treatment and prevention of HCV infection in this area. Outpatients and inpatients were recruited from hospitals in Hohhot from January 2014 to January 2015. In total, 149 patients with HCV infection confirmed by positive anti-HCV and HCV-RNA tests were selected. First, we extracted HCV RNA. cDNA. was obtained. using reverse transcription, then NS5B regions were amplified using a nested polymerase chain reaction (PCR), which enabled 94 cases to be sequenced. We compared sequences in NCBI BLAST, which revealed the reference sequence of maximum similarity and enabled identification of HCV genotypes. Then, a homologous relationship tree was created using MegAlign clustal W. Finally, the distribution characteristics in HCV genotypes, as well as the relationship between genotypes and host age and sex, were obtained. Genotype lb accounted for 73. 40% (69/94), 2a for 19. 14% (18/94), 3a, 3b, and 6a for 2. 12% (2/94), respectively, and 6u for 1. 06% (1/94). The genotype distribution of men and women showed no significant difference (P>O . 05) in 93 cases for whoni explicit sex-specific data were available. Age data for 90 patients revealed the age of disease onset of the 1and2 types to be significantly higher than that of the 3and6 -types (P<0. 05). Hence, genotype lb was the most prevalent in Hohhot (lb has been reported to be the -predominant genotype in the general population of China, followed by genotype 2a). Other, less prevalent genotypes were 3a, 3b, 6a and 6u. Genotype 4 and genotype 5 were not found.

To understand the genotype and the mutation of amino acid (aa) in the major hydrophilic region (MHR) of hepatitis B virus(HBV). The serum samples were collected from the surveillance of HBV among population in Henan in 2012. The S gene of HBV was amplified and sequenced. The acid amino sequences were analyzed with Mega6. 0 software. A total of 50 sequences of HBV S gene were contained, including 8 sequences of genotype B(16. 0%) and 42 sequences of genotype C (84. 0%). The main serotype of HBV among Henan population was adrq+ (84. 0%) . The mutation rate of T1261 was the highest (14. 0%). The overall prevalence of mutant strain of MHR was 24. 0% (12/50), and it was 37. 5% (3/8) for genotype B,21. 4% (9/42) for genotype C. HBV genotype C was predominant in Henan,followed by genotype B. The adrq+ serotype was predominant followed by adw2. The mutation of amino acid in,MHR of HBV was detected in this study. It is necessary to strengthen the surveillance for HBV mutation to provide accurate information during immunization process and HBIG therapy.

During replication of the hepatitis B virus (HBV) in liver cells, the reverse transcription of pre-genomic RNA (pgRNA) is initiated by protein priming at an RNA packaging signal ε located near the 5' end of pgRNA. Heat-shock proteins (Hsps) such as Hsc70, Hsp40, and Hsp90 have been reported to be involved in the reconstitution of HBV polymerase (P protein) and E. The P - E complex initiates the reverse transcription and assembly of nucleocapsids. Hence, blockade of P - ε interactions is an attractive target for drug intervention. We explored the influence of the Hsp inhibitor KNK437 on replication and transcription of the HBV. Three working models were applied: HepG2. 2. 15 cell line; Huh7 cells transfected transiently with the 1. 05 X HBV (pCH9-3091) plasmid; Huh7 cells transfected transiently with the 1. 3 X HBV (pGEM-1. 3 X HBV) plasmid. Cytotoxic effects of KNK437 were detected by the CCK-8 method. Levels of hepatitis B surface antigen (HBsAg) and hepatitis B viral protein (HBeAg) in the media secreted from cells were measured using an ELISA. Intracellular HBV DNAs within nucleocapsids were measured by quantitative polymerase chain reaction (qPCR), and intracellular HBV RNAs by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Transcription of Hsps in cells was determined by qRT-PCR. Data suggested that KNK437 reduced the extracellular secretion of HBsAg and HBeAg in most cases; it downregulated expression of intracellular HBV DNAs within nucleocapsids and RNA transcripts. The lowest rate of viral DNAs in KNK437-treated hepatocytes for all experimental groups was ~1. 5%o (control, 100%), whereas that for RNAs was ~30%. Western blotting revealed KNK437 to inhibit intracellular core expression in HepG2. 2. 15. As a general inhibitor, KNK437 suppressed transcription of hsp70, hsp90b, and hsp4o. These data suggest that KNK437 may be a potent anti-HBV inhibitor for future therapy against chronic hepatitis.

Reverse transcription loop-mediated isothermal amplification (RT-LAMP) was used to detect hepatitis C virus (HCV) lb and 2a (the major genotypes in China). First, clinical samples were collected, and the genotypes and viral load determined. Second, RT-LAMP primers of HCV lb and 2a were designed according to the 5' untranslated region of the HCV. Third, the specificity of RT-LAMP was tested by non-lb and non-2a HCV viruses, and the products analyzed by endonuclease. Fourth, the limit of detection was tested using diluted samples, and the results determined by calcein/Mn(2+) -dependent visual methods. Finally, the consistency of RT-LAMP and real-time fluorescent polymerase chain reaction (PCR) was compared to evaluate the clinical practicality. Results showed that RT-LAMP primers had good specificity because there was no cross-reactivity and the target sequences were identified correctly by endonuclease. The limit of detection was 100 IU/mL and calcein/Mn(Z+)-dependent visual methods were easier to use compared with electrophoresis. After analyses of all amplification results by statistical software; we found no significant difference between RT-LAMP and real-time fluorescent PCR (P> 0. 05). In conclusion, RT-LAMP requires only simple apparatus and simple operation, which is very helpful in primary-health-care institutions.

Infectious Salmon anaemia virus (ISAV) has become a threat to the salmon industry worldwide and has caused considerable economic loss. In the present study, 9 suspect cases of ISAV infection were identified from iced Atlantic salmons imported from Norway in 2014 through Shenzhen port (Shenzhen, China) using methods recommended by the World Organization for Animal Health. However, the results of virus isolation were negative., Based on the sequence analysis of ISAV segment 6, the 9 ISAV isolates belonged to the HPRO type, had high homology (98.3%~100.0%) and closest relationship with Norway strains. We identified the 9 positive HPRO ISAVs from 491 iced Atlantic salmons (1. 8%). Therefore, we should strengthen the quarantine of iced Atlantic salmons from Norway in case of HPRO ISAV into China.

Digital polymerase chain reaction (dPCR) is a new method for absolute quantification. However, an absolute quantification method for influenza A viruses based on droplet digital polymerase chain reaction (dPCR) has not been established. In this study, we found that: (i) the annealing temperature of dPCR was optimized at 64, 4°C; (ii) the detection range of dPCR was 37.7 approximately 8.22 X 10(4) copies/μl for influenza A viruses; (iii) the limit of detection of dPCR was 3. 77 copies/reaction. The liner correlation coefficient (R(2)) was found to be 0. 9988, suggesting the high reliability of our dPCR method. The dPCR method could be used to detect influenza A viruses clinically. In summary, we developed a dPCR method for absolute quantification of influenza A viruses. This method could be used effectively to quantify influenza A viruses in clinical samples. Therefore, our method could be a new tool for the absolute quantification of viral load.

Infection by the canine distemper virus (CDV) results in a fulminating infectious disease that causes serious harm to dogs. With breaking 'of the CDV into primates, some researchers wonder if the CDV will cause a serious infection in humans. To better understand the potential of the CDV to infect humans, the molecular characteristics of the CDV, how it infects target cells in the host, the key receptors involved in infection, and infection of human cells in vitro were assessed in this review. There is no direct evidence that CDV can colonize and grow in humans. Two key receptors, SLAM and nectin-4, in hunans and primates have high identity, and the CDV can infect human cells in vitro. Therefore, we must pay close attention to the potential threat of infection by the CDV in humans.