ABSTRACT
Objective:To analyze the molecular characteristics of Echovirus 11 (Echo11) strains isolated in Xiangyang, Hubei Province from 2016 to 2017 based on the sequences of VP1 gene.Methods:Rectal and throat swab specimens were collected from children with hand, foot and mouth disease (HFMD) in Xiangyang from 2016 to 2017. Echo11 strains were detected by real-time reverse transcriptase PCR (RT-PCR) and isolated after cultured in human rhabdosarcoma (RD) cells. The VP1 regions of Echo11 strains isolated from RD cells and the whole genomes of three representative Echo11 strains were amplified by conventional RT-PCR and the sequences were analyzed. DNAStar7.0 (MegAlign) and MEGA6.0 (Data) were used to analyze the homology and mutation sites in nucleotide and amino acid sequences. Neighbor-joining method was used to construct phylogenetic trees. Recombination analysis was performed with SimPlot software (BootScanning).Results:A total of 11 Echo11 strains were isolated from 3 494 HFMD cases, accounting for 0.31%. They were highly homologous in the VP1 gene. These strains shared 98.4%-100.0% homology in nucleotide sequences and 98.3%-100.0% homology in amino acid sequences. The homology between the 11 Echo11 strains and the prototype strain (Echo11/Gregory, X80059) was 73.9%-74.8% in nucleotide sequences and 87.7%-88.7% in amino acid sequences. All of the Echo11 strains circulating in Xiangyang were classified into lineage D, having a similarity to the strains circulating in some regions of mainland China since 2013. In multiple regions of the genome, the Echo11 strains isolated in Xiangyang were highly similar to the Henan Echo1 strains in 2010 and the Hubei Echo6 strains in 2015, suggesting there was recombination within the genome of Echo11 strains in Xiangyang.Conclusions:The Echo11 strains circulating in Xiangyang from 2016 to 2017 belonged to lineage D and were recombinant strains.
ABSTRACT
Venezuelan equine encephalitis (VEE) is a zoonotic disease caused by the Venezuelan equine encephalitis virus (VEEV) complex. This disease has not yet been reported in China, and it is therefore essential to establish a rapid and accurate method for detection of the virus in order to prevent and control this disease. In this study, a one-step real-time quantitative RT-PCR method was developed for the detection of the VEEV complex. A pair of specific primers and a Taqman probe were designed corresponding to a conserved region of the VEEV gene nspl, allowing the detection of all known strains of different sub- types of the virus. Using RNA synthesized by in vitro transcription as template, the sensitivity of this method was measured at 3.27 x 10(2) copies/microL. No signal was generated in response to RNA from Chikungunya virus (CHIKV), nor to RNA encoding the nsp1 fragment of Eastern equine encephalitis virus (EE-EV) or Western equine encephalitis virus (WEEV), all of which belong to the same genus as VEEV. This indicates that the method has excellent specificity. These results show that this one-step real-time quantitative RT-PCR method may provide an effective tool for the detection of VEEV in China.
Subject(s)
Humans , China , DNA Primers , Genetics , Encephalitis Virus, Venezuelan Equine , Classification , Genetics , Encephalomyelitis, Venezuelan Equine , Virology , RNA, Viral , Genetics , Reverse Transcriptase Polymerase Chain Reaction , MethodsABSTRACT
Objective To analyze the spatial distribution of HIV/AIDS epidemics among injecting drug users (IDUs) in China from 2005 to 2011 and to understand its changing trend.Methods Using data on people living with HIV and AIDS through injecting drug between 2005 and 2011 to analyze the demographic characteristics of injecting drug users.Analysis on spatial correlation (provincial level and country level) and median center of hot spots (country level) were conducted by Arcgis software.Results Sex ratio (male/female) and registered place ratio (province/other provinces) reduced as time went by,with the ratios in 2011 as 6.75 and 7.01 respectively.Tape ratio of the disease between HIV and AIDS showed an upward trend (Z=26.880,P＜0.01).Since 2005,the identified numbers of HIV/AIDS and the spatial correlation and hot spots in provincial level had reduced,the numbers of provincial hot spots were two from 2009 to 2011 (Sichuan and Yunnan provinces) at the national level.However,the spatial correlation and hot spots at the provincial level had an increasing trend.Between 2005 and 2011,the Western Median Centers of hot spots was located in Xinjiang province while the Southwestern Median Center of hot spots tended to move towards the north.Conclusion The demographics changes of HIV/AIDS infection among injecting drug users seemed to be regular from 2005 to 2011.Spatial correlation at the provincial level was reducing.However,the spatial correlation and the numbers of hot spots at the country level increased,with hot spots at the country level tended to move from the border areas towards inland.