Sequence analysis of VP1-VP4 genes of coxsackievirus A6 strains isolated from children with severe hand, foot, and mouth disease in Shenzhen from 2012 to 2015 / 中华微生物学和免疫学杂志

Objective To analyze the genetic characteristics of VP1-VP4 genes carried by cox-sackievirus A6 (CVA6) strains isolated from severe cases of hand, foot, and mouth disease (HFMD) in Shenzhen during 2012 to 2015. -ethods The VP1-VP4 genes of CVA6 strains isolated from severe HFMD cases in Shenzhen during 2012 to 2015 were amplified and sequenced. Phylogenetic analysis was performed to analyze the VP1-VP4 genes of CVA6 isolates and sequences downloaded from GenBank by using DNASTAR6. 0 and MEGA6. 02 software packages. Results Four cases of severe HFMD were caused by CVA6 in Shenzhen during 2012 to 2015. All of the patients had the symptom of fever, skin rash and aseptic encephalitis. The CVA6 strain causing severe HFMD in 2013 shared 98. 8％-98. 9％ homology in nucleotide sequences and 99. 3％-99. 8％ in amino acid sequences with the strains isolated in 2012. Two amino acid mutations were found in the CVA6 strain isolated in 2013, which were G73E in VP2 region and S13G in VP1 region. However, the CVA6 strain isolated in 2015 only shared 95. 0％ homology in nucleotide sequences and 99. 3％ homology in amino acid sequences with the strain isolated in 2013. Six amino acid mutations were identified including E73G in VP2 region and T5A, S27N, A30V, N137S and V242I in VP1 region. The phylogenetic analysis revealed that the four CVA6 strains belong to D3 sub-genotype. The CVA6 strains causing severe cases in 2012 had the nearest genetic relationship with the strain isolated in Changsha in 2012 (KJ156349). The CVA6 strain isolated in Shenzhen in 2013 had the nearest genetic relationship with the strain isolated in Shanghai in 2013 (KJ612513). The Shenzhen CVA6 isolate in 2015 showed high similarity to Weifang CVA6 isolate in 2014 (KX752785). Conclusions All CVA6 strains causing severe HFMD ca-ses in Shenzhen during 2012 to 2015 belongs to D3 sub-genotype. Mutations of S27N and A30V in the VP1 region of the CVA6 isolate in 2015 are located in the B cell epitopes. In addition, the VP1-V242I mutation in the CVA6 strain isolated in 2015 is located in the binding site of PSGL-1 receptor. These mutations may affect the binding of CVA6 strains to the cellular receptors and their infectivity to people.

Rescue of porcine circovirus type 2 from cloned DNA / 生物工程学报

Infectious clone is a useful tool in exploring viral replication and pathogenesis. In order to prevent linear PCV2 cyclization, PCR mutagenesis was used to construct the first molecular clone (pSK-2PCV2) by ligating two copies of the complete PCV2 genome with the pBluescript SK (pSK) vector. In addition, pSK-PCV2 and ds-PCV2 were constructed. PK-15 cells were transfected with above three infectious clones. Indirect immunofluorescence assay (IFA) revealed that the virus antigen mainly localized in infected cell nucleolus and cytoplasm. PCV2 specific nucleotide fragment in cell culture was amplified by RT-PCR. Typical porcine circovirus particles with diameter about 17 nm were also observed by transmission electron microscope (TEM) in the infected cells. The rescued virus sequences from the cultures had 100% homology with the inserting PCV2 genome. The rescued virus shared similar properties with that of the parental virus. The study establishes a platform for further research on the virus molecular biology and pathogenicity.

Clinical Research of Neck-type Cervical Syndrome Treated with Isometric Neck Strength Training / 广州中医药大学学报

Objective To evaluate the effectiveness and safety of isometric neck strength training for the treatment of neck-type cervical syndrome.Methods The qualified patients with neck-type cervical syndrome were divided into two groups by stratified randomization: the treatment group(N=55)received isometric neck strength training,and the control group(N=40) received manipulation treatment.Two weeks constituted one treatmeat course.Visual Analog Scale(VAS) and Vernon Cervical Disability Index(VCDI) were used to evaluate the efficacy,and the safety was also monitored.Results All of the 95 enrolled patients were followed up for 3~11.4 months.No aggravation was found in the treatment group,but in the control group one patient developed into cervical spondylotic radiculopathy and one patient developed into sympathetic cervical spondylosis.The frequency of serious neck pain attack within 3 months was 6.65?2.62 times in the control group and 2.27?1.50 times in the treatment group,the difference being significant(P0.05);the result of follow-up on the 3rd month after treatment showed that the difference of VCDI score was significant between the two groups(P