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Objective:To investigate the whole genome characteristics of coxsackievirus A4 (CVA4) circulating in Qingdao city.Methods:Four CVA4 isolates circulating in Qingdao city during 2013 to 2015 were selected. Whole genome sequences of these strains were amplified by one-step reverse transcription-polymerase chain reaction (RT-PCR). Sequence alignment and phylogenetic analysis were performed using MEGA7.0 software package. Genetic recombination analysis was performed using similarity plots 3.5.1 software package.Results:Phylogenetic analysis showed that based on the sequences of the whole genome and P1, P2 and P3 regions, HS312/QD/CHN/2013 and HS605/QD/CHN/2014 strains together with the early domestic isolates belonged to the same clade, while FY218/QD/CHN/2015 strain and CV-A4/P1033/2013/China strain collected in Wenzhou in 2013 formed another clade in each phylogenetic tree. HS144/QD/CHN/2014 strain belonged to the same clade as HS312/QD/CHN/2014, HS605/QD/CHN/2014 and the early domestic CVA4 isolates in the phylogenetic tree based on the P1 region, but formed a separate clade in the phylogenetic trees based on the whole genome, P2 region and P3 region. Genetic recombination analysis revealed that there was genetic recombination between HS144/QD/CHN/2014 strain and the CVA2 strain of CV-A2/P373/2013/China isolated in mainland China in 2013 in the region of 2C-3D (5 081-7 301); FY218/QD/CHN/2015 and CV-A4/P1033/2013/China strains were highly homologous and recombination signal sequences were detected in the region of 2A-2B (3 821-4 161) between the two strains and the CVA2 strain of CV-A2/P373/2013/China.Conclusions:The CVA4 isolates circulating in Qingdao city presented obvious genetic diversity at the genome-wide level.
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Objective@#To investigate the etiology spectrum of hand foot and mouth disease (HFMD) and to analyze the molecular characteristics of Coxsackievirus A10 and A6 in Qingdao in 2014.@*Methods@#Throat swabs of HFMD cases were tested for total enteroviruses (EVs), EV-A71, CV-A16, CV-A10 and CV-A6 by multiplex real time RT-PCR. Other EV serotypes were identified through the sequences of partial VP1 gene. The full-length of VP1 gene of CV-A10 and CV-A6 were amplified and sequenced. The sequences were phylogenetically analyzed using MEGA 5.0 software package.@*Results@#A total of 1727 HFMD patients were detected in 2014 and 11serotypes of enteroviruses were identified. EV-A71(38.0%, 410/1078), CV-A16(28.8%, 311/1078), CV-A10(14.1%, 152/1078)and CV-A6(3.2%, 34/1078)were the most dominant pathogen in 2014 in Qingdao. Proportions of CV-A10 in enterovirus infected children varied dramatically in different ages(χ2=15.19, P=0.001), showing a downtrend with age. Proportion of CV-A10 in inpatients was much higher than that in outpatients(χ2=49.1, P <0.001), while 60% of those inpatients showed nervous system damage symptoms, with pathological reflex or disappearance of physiological reflex. Phylogenetic analysis of complete VP1 sequences showed that all CV-A10 strains identied in this study belonged to genotype C, 71.7% of which located in branch C5; all CV-A6 strains belonged to genotype D while 83.3% of which located in branch D5.@*Conclusions@#EV-A71, CV-A16, CV-A10 and CV-A6 were the prevalent pathogens of HFMD in Qingdao in 2014. CV-A10 was more frequently detected in lower age group with HFMD, which can cause damage to nervous system. Strains of branch C5 in genotype C were the dominant strains of CV-A10 circulated in Qingdao in 2014 while strains of branch D5 in genotype D were the major strains of CV-A6.
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Objective@#To analyze the molecular epidemiology of norovirus (NoV) genotype GⅡ.15 in Qingdao City.@*Methods@#One thousand four hundred and twelve stool samples were collected from suspected NoV infected patients and detected by real-time polymerase chain reaction (PCR). Open reading frame (ORF)1-ORF2 and VP1 gene were amplified by reverse transcription (RT)-PCR and sequenced for genotyping, evolutionary analysis and homology modeling.@*Results@#Seven cases of GⅡ.15 type were detected including four sporadic cases and one outbreak.The VP1 gene was highly homologous and had little variation compared with early strain J23/US/1999. The differences of amino acids between strains in Qingdao City were mainly asparagine/asparticacid(N/D)300 and proline/serine(P/S)302.Homology modeling suggested that VP1 of GⅡ.15 strain was composed of S domain and P domain (P1 subdomain included 224-276 and 431-555, P2 subdomain included 277-430). S domain contained eight anti-parallel β-sandwiches and two α-helixes, and P1 subdomain contained one α-helix and seven β-strands, and the P2 subdomain folded into a compact barrel-like structure consisting of six β-strands.Argnine (R)-glycine (G)-valine (V)-motif (289-291) and three specific loci including glutarnine (Q)313, asparagine (N)349 and Q389 were located in the P2 subdomain, with NGR-motif (265-267) located at 22nd upstream of RGV-motif.Site I (SNR-alanine(A)- histidine(H)357-361), Site Ⅱ (D388) and Site Ⅲ (G454, G455) were the main characteristic sites of histo-blood group antigens (HBGA) binding interface, which may be similar to the binding pattern of GⅡ.4 type VA387 and HBGA.@*Conclusion@#Although GⅡ.15 type NoV evolves very slowly, it may still have the risk to become an epidemic strain, which needs to be monitored and further studied.
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Objective To analyze the molecular epidemiology of norovirus (NoV) genotype G Ⅱ.15 in Qingdao City.Methods One thousand four hundred and twelve stool samples were collected from suspected NoV infected patients and detected by real-time polymerase chain reaction (PCR).Open reading frame (ORF) I-ORF2 and VP1 gene were amplified by reverse transcription (RT)-PCR and sequenced for genotyping,evolutionary analysis and homology modeling.Results Seven cases of GⅡ.15 type were detected including four sporadic cases and one outbreak.The VP1 gene was highly homologous and had little variation compared with early strain J23/US/1999.The differences of amino acids between strains in Qingdao City were mainly asparagine/asparticacid(N/D) 300 and proline/serine (P/S) 302.Homology modeling suggested that VP1 of GⅡ.15 strain was composed of S domain and P domain (P1 subdomain included 224-276 and 431-555,P2 subdomain included 277-430).S domain contained eight anti-parallel β3-sandwiches and two α-helixes,and P1 subdomain contained one α-helix and seven β3-strands,and the P2 subdomain folded into a compact barrel-like structure consisting of six β-strands.Argnine (R)-glycine (G)-valine (V)-motif (289-291) and three specific loci including glutarnine (Q)313,asparagine (N)349 and Q389 were located in the P2 subdomain,with N GR-motif (265-267) located at 22nd upstream of RGV-motif.Site Ⅰ (SNR-alanine (A)-histidine (H)357-361),Site Ⅱ (D388) and Site IⅢ (G454,G455) were the main characteristic sites of histo-blood group antigens (HBGA) binding interface,which may be similar to the binding pattern of G Ⅱ.4 type VA387 and HBGA.Conclusion Although G Ⅱ.15 type NoV evolves very slowly,it may still have the risk to become an epidemic strain,which needs to be monitored and further studied.
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Objective To investigate the molecular epidemiological characteristics of hemaggluti-nin (HA) and neuraminidase (NA) of influenza B viruses (IBV) isolated in Qingdao from 2011 to 2018. Methods A total of 12236 samples of influenza-like cases in Qingdao from 2011 to 2018 were collected to extract viral RNAs. All samples were screened for influenza A viruses ( IAV) and IBV by one-step multiplex real-time RT-PCR. Lineages of IBV were identified. One hundred and eighty-two strains of IBV were select-ed to amplify HA and NA genes by RT-PCR and then analyzed by sequencing. Phylogenetic analysis and variation analysis of genes and amino acids were carried out. Results IBV was detected almost every year in Qingdao from 2011 to 2018. The positive rate was only slightly lower than that of IAV ( 4. 99％ vs 6. 21％). B/Victoria linkage had two prominent epidemic years (2011-2012, 2015-2016), while B/Yama-gata linkage had three (2013-2014, 2014-2015, 2017-2018). Most of the infected people were children un-der 10 years old, and the people infected with the two lineages had similar age characteristics. Phylogenetic analysis of HA genes showed clusters in Victoria clades of 1A and 1B and Yamagata clades of 2 and 3. IBV of Yamagata lineage had more amino acid mutation sites than those of Victoria lineage in HA genes with grea-ter genetic diversity. The B/Yamagata strains had 12 amino acid mutations and the B/Victoria strains had seven in four major epitopes. In the receptor binding sites, two amino acid mutations were detected in the B/Yamagata strains and three in the B/Victoria strains. In Qingdao, 26 strains of IBV were intra-lineage reas-sortments, mostly of the B/Victoria lineage, and 23 strains were inter-lineage reassortments, mostly between HA-B/Yamagata and NA-B/Victoria strains. A possible resistant strain to NA inhibitor was found. Conclu-sions The significance of IBV in seasonal influenza should not be neglected. Amino acid substitution, in-sertion/deletion and gene reassortment were the main strategies for the natural evolution of IBV. Influenza surveillance was of great importance and influenza vaccine strains needed to be updated in time.
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Objective@#To illuminate the gene characteristics and clinical characterization of Coxsackievirus B5 (CV-B5) strains isolated from patients with sevre hand, foot and mouth disease (HFMD) in Qingdao city.@*Methods@#A total of 1 844 patients of HFMD were consecutively admitted to Qingdao Women and Children's Hospital from 2013 to 2014. Information of the study population described above was collected retrospectively. The samples were collected from at least 1 site (throat swab, cerebrospinal fluid), which viral nucleic acid extracted and the entire VP1 gene sequences of CV-B5 isolates were amplified and sequenced, then the homology and phylogeny analysis were conducted by MEGA7.0. The prototype Faulkner strain and other VP1 amino acid sequences were derived from the GenBank database.@*Results@#A total of 8 CV-B5 positive cases were obtained, including 4 males and 4 females; 6 severe hospitalized cases and 2 outpatients. The age of 6 hospitalized patients ranged from 3 to 48 months, with a median of 26 months. For the six inpatients, fever, convulsions vomiting, diarrhea and rash were the main clinical manifestation, and all combined with viral encephalitis. Compared with the prototype strain Faulkner, in the VP1 region,the nucleotide and the amino acid homologies was 77.3%-78.8% and 95.5%-97.0% respectively. Five out of the six severe cases with substitution of serine (S) to asparagine (N) at amino acid site 95 in the VP1 region. The sequences of 8 CV-B5 strains were classified into genogroup D.@*Conclusion@#Hand, foot and mouth disease associated with CV-B5 virus infection can result in nervous system involvement and the main complication was viral encephalitis. The CV-B5 strains associated with severe hand, foot and mouth disease had high nucleotide homology and present a certain regional aggregation.
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Objective To investigate the molecular characteristics of coxsackievirus A12 ( CV-A12) and to understand the clinical manifestations of severe hand, foot and mouth disease (HFMD) caused by CV-A12 in Qingdao. Methods Throat swabs of HFMD, herpangina and influenza-like cases from 2011 to 2016 were detected for enteroviruses ( EVs) in Qingdao. Human rhabdomyosarcoma ( RD) and human la-ryngeal carcinoma (Hep-2) cells were used for virus proliferation and CV-A12 strains were identified through a semi-nest RT-PCR. The full-length of VP1 gene of CV-A12 strains was sequenced and phylogenetically an-alyzed using MEGA7. 0 software package. Clinical data of severe HFMD cases positive for CV-A12 were col-lected and analyzed. Results CV-A12-positive HFMD, herpangina and influenza-like cases accounted for 0. 3％(18/6798), 1. 2％(2/169) and 0. 1％(1/676) in Qingdao, respectively. Most of the HFMD caused by CV-A12 in children were mild before 2013 (84. 6％, 11/13), while hospitalized severe cases with neurological symptoms (100％, 5/5) became more common after 2013. Phylogenetic analysis of the VP1 region revealed that CV-A12 strains worldwide could be divided into two genotypes, A and B. All of the CV-A12 strains successfully sequenced in Qingdao from 2011 to 2016 belonged to genotype B, and 88. 9％(16/18) of them belonged to subgenotype B2. All hospitalized severe cases of CV-A12-caused HFMD after 2013 were associated with strains in branch B2b of subgenotype B2. Conclusion CV-A12 was one of the pathogens causing HFMD, herpangina and influenza-like illness in children in Qingdao. Strains of genotype B2 were the predominant CV-A12 strains circulating in Qingdao in recent years. CV-A12-caused HFMD might complicated by nervous system damage.
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Objective To analyze the molecular epidemiological characteristics of norovirus (NoV) outbreaks in Qingdao between 2014 and 2016.Methods Stool samples were collected from NoV outbreaks between January 2014 and December 2016 and detected by real-time RT-PCR.NoV open reading frame 1 (ORF1) and ORF2 were partially amplified by RT-PCR.The amplified products were further analyzed by gene sequencing and genotyping.Phylogenetic analysis was conducted by using MEGA 6.0 software package.Results A total of 23 NoV outbreaks, involving 260 cases, were reported during 2014 to 2016.Of all collected stool samples, 128 were positive for NoV including 6 of genogroupⅠ (GⅠ) and 122 of genogroupⅡ (GⅡ).All positive samples were genotyped into 6 genotypes, which were GⅡ.P17-GⅡ.17, GⅡ.P12-GⅡ.3, GⅡ.P7-GⅡ.6、GⅡ.P2-GⅡ.2, GⅠ.Pb-GⅠ.6 and GⅡ.Pg-GⅡ.12.The 23 outbreaks included both single infections and mixed genotype infections, which were 11 of GⅡ.17 single infection, 4 of GⅡ.3 single infection, 3 of GⅡ.17 and GⅡ.3 mixed infection, 2 of GⅡ.17 and GⅡ.6 mixed infection, 1 of GⅠ.6 single infection, 1 of GⅡ.17 and GⅡ.2 mixed infection and 1 of GⅡ.17 and GⅡ.12 mixed infection.Conclusion NoV was an important pathogen responsible for viral diarrhea outbreaks in Qingdao.Several different genotypes were detected.The newly variant GⅡ.P17-GⅡ.17 was the predominant epidemic strain causing norovirus outbreaks in Qingdao during 2014 to 2016.
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Objective@#To analyze the molecular epidemiology of Norovirus(NoV) infection among sporadic hospitalized adults with diarrhea in Qingdao, 2015.@*Methods@#Four hundred and nine stool samples were collected from hospitalized adults with diarrhea and detected by Real-time RT-PCR. For genotyping, ORF1 and ORF2 were partially amplified by RT-PCR and sequenced.@*Results@#18.1%(74/409) of stool samples were positive for NoV genogroup I(GI) (10/74) and genogroup II(G II) (64/74). Fifty-three positive samples of GII were sequenced and divided into 4 genotypes, including GII.Pe-GII.4(26/53), GII.P17-GII.17(19/53), GII.P12-GII.3(7/53) and GII.P16-GII.13(1/53). All GII.4 strains were the variants of GII.4-Sydney-2012. From May to Aug in 2015, GII.4 only accounted for 5.3%(1/19) and GII.17 were the major epidemic strains(68.4%, 13/19). But from Sept to Dec in 2015, GII.17 decreased substantially to 10.9%(6/55) and GII.4 became the most predominated strains (45.5%, 25/55).@*Conclusions@#NoV is an important pathogen responsible for viral diarrhea among adults in Qingdao. GII.4-Sydney-2012 and the newly variant GII.P17-GII.17 were the predominant epidemic strains in Qingdao, 2015.
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Objective To investigate the etiology of hand,foot and mouth disease (HFMD) and to analyze the genetic characteristics of three prevalent enteroviruses in Qingdao in 2015. Methods City-wide surveillance data in 2015 were used to analyze the epidemiological characteristics of HFMD in Qingdao. RNA samples extracted from throat swab of HFMD cases were examined for general enteroviruses (EVs) such as enterovirus 71(EV71), coxsackievirus A16 (CA16) and CA6 by real-time RT-PCR. Full-length VP1 genes of EV-positive specimens were amplified and sequenced. Sequencing results were phylogenetically analyzed using MEGA 7.0 software package. Results A total of 804 patients with HFMD were identified from 1 176 patients in 2015. CA6 (41.4%),EV71 (31.6%) and CA16 (15.3%) were the predominant EVs causing HFMD. Children 5 years of age and under accounted for 80.3% of the 804 HFMD cases. CA6 was responsible for 48.9% of HFMD cases in children under 3 years old. The epidemic subtypes of EV71 and CA16 in Qingdao were C4a and B1b,respectively. Twenty-eight randomly selected CA6 strains were all classified into type A genome. Conclusion CA6, EV71 and CA16 were the prevalent pathogens causing HFMD in Qingdao in 2015. CA6 became the most predominant pathogen,mainly targeting children under 3 years old. C4a remained the prevailing subtype of EV71,while different from the co-prevalence of B1a and B1b subtypes in the past,B1b became the predominant subtype of CA16. CA6 strains circulating in Qingdao in 2015 mainly belonged to type A genome and evolved into multiple smaller branches. However, CA6 strains isolated in Qingdao in 2015 and 2013 located in different branches.
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BACKGROUND:MicroRNAs are widely involved in the regulation of protein expression, and play a critical role in many physiological and pathological processes in the body. But microRNA expression profile in degenerative lumbar scoliosis is rarely reported and understood. OBJECTIVE:To compare the microRNA expression profile in the normal intervertebral disc and degenerative lumbar scoliosis and to identify degenerative lumbar scoliosis-specific microRNAs, folowed by functional validation. METHODS: Total RNA samples were extracted from the nucleus pulposus tissues of 57 patients with degenerative lumbar scoliosis as experimental groups and the normal nucleus pulposus tissues of 42 patients with lumbar fractures as control group. An initial screening of differentialy expressed microRNAs in the nucleus pulposus tissues by microRNA microarray was performed in 10 samples from each group. Subsequently, differentialy expressed microRNAs were validated using real-time quantitative RCR. The level of differentialy expressed microRNAs in the degenerative nucleus pulposus tissues was investigated. Then, the functional analysis of microRNAs in regulating colagen II expression was carried out. Western blot and luciferase reporter assay were also used to detect target genes. RESULTS AND CONCLUSION:We identified 22 microRNAs that were differentialy expressed (17 upregulated and 5 downregulated) in degenerative lumbar scoliosis patients compared with the controls. Folowing real-time quantitative RCR confirmation, miR-491-5p was significantly down-regulated in degenerative nucleus pulposus tissues in comparison with the controls. Moreover, its level was closely correlated with the pathological grading of disc degeneration. Overexpression of miR-491-5p promoted type II colagen expression in nucleus pulposus cels. Bioinformatics target prediction identified matrix metaloproteinase-9 as a putative target of miR-491-5p. Furthermore, luciferase reporter assays demonstrated that miR-491-5p directly targeted matrix metaloproteinase-9 and affected its protein expression in nucleus pulposus cels. These results show that the downregulation of miR-491-5p induces type II colagen loss by directly targeting matrix metaloproteinase-9, thereby resulting in degeneration of the intervertebral disc and degenerative lumbar scoliosis. This study also underscores the potential of miR-491-5p as a novel therapeutic target in degenerative lumbar scoliosis.
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BACKGROUND:MicroRNAs (miRNAs) play an important role in a variety of diseases. Investigation of miRNA expression profile in degenerative lumbar scoliosis is beneficial for understanding its pathogenesis, providing a novel therapeutic target. Therefore, we tested the hypothesis that miRNAs promote intervertebral disc degeneration through the interleukin-10/STAT3 signaling pathway, a potential regulator of intervertebral disc degeneration. OBJECTIVE:To compare the differentialy expressed miRNAs in the intervertebral disc tissues from patients with degenerative lumbar scoliosis and normal controls and to identify specific miRNAs in degenerative lumbar scoliosis folowed by functional validation. METHODS: An initial screening of miRNA expression in nucleus pulposus tissues by miRNA Solexa Sequencing was performed in samples from 10 patients with degenerative lumbar scoliosis and 10 controls, respectively. Subsequently, differentialy expressed miRNAs were validated using qRT-PCR. The level of differentialy expressed miRNAs in degenerative nucleus pulposus tissues was investigated. Then, functional analysis of the miRNAs in regulating type II colagen expression was carried out. Western blot and luciferase reporter assay were used to further confirm the target gene. RESULTS AND CONCLUSION: We identified 30 miRNAs that were differentialy expressed (16 upregulated and 14 downregulated) in patients with degenerative lumbar scoliosis compared with controls. Folowing qRT-PCR confirmation, Has-let-7f was significantly down-regulated in degenerative nucleus pulposus tissues as compared with controls. Moreover, its level was correlated with the severity of disc degeneration. Overexpression of Has-let-7f promoted type II colagen expression in nucleus pulposus cels. Knockout of interleukin-10 induced effects on nucleus pulposus cels similar to Has-let-7f. Bioinformatics target prediction identified interleukin-10 as a putative target of Has-let-7f. Furthermore, luciferase reporter assays demonstrated that Has-let-7f altered the expression of STAT3 and matrix metaloproteinase-2. These findings indicate that the downregulation of Has-let-7f induces type II colagen loss by directly targeting inleukin-10, thereby resulting in intervertebral disc degeneration and degenerative lumbar scoliosis. Has-let-7f is likely to be a novel therapeutic target for degenerative lumbar scoliosis.
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Objective To investigate the effects of enhanced external counterpulsation on coronary heart diseas epatients who suffer from insomnia .Methods Ninety-two cases of coronary heart disease patients with insomnia were divided into observation group and control group randomly ,46 cases in each group .The cases in control group were given routine drug treatment and nursing for coronary heart disease and insomnia .On this base ,the cases in observation group were given EECP .Use the pittsburgh sleep quality index (PSQI) to evaluate the sleep quality of two groups on day of admission and 30d after treatment .The dimensions score and total score of two groups in each time were compared and analyzed .Results After the intervention of 30 d ,PSQI scores in the observation group were lower than those before intervention ,and lower than that of control group ,and there was statistical signifi-cance(P<0 .05) .Conclusion The EECP can relieve the insomnia of coronary heart disease patients ,and improve there sleep quali-ty .
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Objective To investigate the etiology spectrum of hand , foot and mouth disease ( HFMD) and to analysis the molecular characteristics of three predominant human enterovirus stains in Qingdao in 2013.Methods The total enterovirus (EV) strains and strains of EV71, CVA16 and CVA6 in throat swabs of HFMD cases were detected by using multiplex real time RT-PCR.The full-length of the viral VP1 genes of the EV strains were amplified and sequenced .The sequences were phylogenetically analyzed by using the MEGA5.0 software package .Results A total of 841 patients with mild HFMD and 107 patients with serious HFMD were recruited in this study and 64 .3%of them were positive for EV .The predominant pathogens were EV71 (44.8%), CVA6 (28.2%) and CVA16 (9.5%) in 2013.CVA6 replaced CVA16 as the second most common pathogen for HFMD , accounting for 42.7% of all pathogens in children aged less than 3 years and 22.2%of all pathogens in the serious patients .The proportions of CVA6 in the etiology spectrum showed a downtrend along with the increasing age of the patients (P<0.001).Phylogenetic analy-sis of the complete VP1 gene sequences showed that all of the EV 71 strains identified in this study belonged to the subgenotype C4 (evolutionary branch C4a) and all of the CVA16 strains belonged to the subgenotype B1 (evolutionary branches B1a and B1b).There were 6 genogroups (A to F) regarding to the VP1 gene of CVA6 and all of the CVA6 strains identified in this study belonged to genogroups A and D .Among the CVA6 strains isolated in Qingdao in 2013, 83.9% belonged to genogroup A, while the rest 16.1% belonged to genogroup D.66.7%of the CVA6 strains isolated in 2012 belonged to genogroup A, while the rest 33.3%belonged to genogroup D .All of the CVA6 strains isolated from year 2008 to 2011 in Qingdao belonged to genogroup D.Conclusion EV71, CVA6 and CVA16 were the prevalent pathogens responsible for the de-velopment of HFMD in Qingdao in 2013.The proportions of CVA6 strains in the etiology spectrum showed a downtrend with the increasing age in children .C4a was the major subtype of EV71 strains circulating in Qingdao in 2013, while B1a and B1b were the major subtypes of CVA16 strains.The pattern of endemic cir-culation of CVA6 strains showed a trend of changing from genogroup D to A from year 2008 to 2013 .
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Objective To analyze the etiologic spectrum of hand, foot and mouth disease (HFMD) and the molecular characteristics of coxsackievirus A10 (CVA10) strains isolated in Qingdao from year 2010 to 2012.Methods Throat swab specimens were collected from patients with HFMD to detect to-tal enteroviruses ( EVs) , EV71 and CVA16 strains by multiplex real time RT-PCR.The EV-positive speci-mens were further detected by a semi-nested RT-PCR to amplify the sequence of viral genes encoding VP1. The serotypes of EVs were identified based on the sequences of genes encoding VP1.The full-length gene se-quences encoding VP1 of CVA10 isolates were amplified and sequenced. The phylogenetic analysis was con-ducted by using MEGA5.0 software package.Results A total of 1919 outpatients with mild HFMD and 1336inpatients with serious HFMD were recruited in this study .CVA16 strains were the predominant patho-gen for outpatients in year 2010 ( prevalence rate of 53%) and 2012 ( prevalence rate of 73%) .EV71 strains were the predominant pathogen for outpatients in year 2011 ( prevalence rate of 78%) and inpatients in year 2010 ( prevalence rate of 70%) and 2011 ( prevalence rate of 86%) . Some serotypes other than CVA16 or EV71 were the predominant pathogens for inpatients in year 2012 ( prevalence rate 44%) . CVA10 strains were identified in 12 patients with HFMD in year 2010and 17 patients with HFMD in 2012. The full-length gene sequences encoding VP1 of 23 CVA10 isolates were successfully amplified and se-quenced.The phylogenetic analysis showed that the 23 CVA10 isolates all belonged to genotype C and could be further divided into six clades.The genes encoding VP1 of the 23 CVA10 strains shared 97.3% to 1000.%homologies in amino acid sequences.The CVA10 isolates were also similar to their counterparts isolated from other regions during the same period.Conclusion CVA16 and EV71 strains were the preva-lent pathogens of HFMD in Qingdao from year 2010 to 2012, co-circulated with some other serotypes of EVs, especially CVA10 strains.The CVA10 strains belonged to genotype C and shared high homologies among them and their counterparts circulated in other regions during the same period.
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Objective To study the whole-genome evolution of influenza B viruses prevalent in Qingdao from 2006 to 2011 .Methods RNA was extracted from influenza B viruses isolated in Qingdao from 2006 to 2011 .Each gene segment was amplified by reverse transcription polymerase chain reaction ( RT-PCR) and then sequenced .Gene sequences of each virus were determined and assembled by using Sequench -er software .A phylogenetic analysis for each gene segment was conducted by using MEGA 5.0 software pack-age.Results The phylogenetic tree of hemagglutinin ( HA) gene showed that 13 strains from 2006 to 2009 belonging to V1 clade of Victoria lineage were B/Malaysia/2506/2004-like viruses,and 12 strains from 2009 to 2011 belonging to the V2 clade of Victoria lineage were B/Brisbane/60/2008-like viruses.Moreover, strains of Yamagata lineage were all B/Florida/4/2006-like viruses including 5 strains of Y1 clade circulated from 2006 to 2008 and 7 strains of Y2 clade circulated from 2010 to 2011, respectively.The analysis of whole-genome evolution showed that 3 viruses of V2 clade presented 5+3 reassortment and 1 virus presented 1+7 reassortment.All reassortant strains matched with the vaccine strains of the present and previous season . The Yamagata and Victoria lineage strains belonged to genotype 2 and genotype 15,respectively.Compared with vaccine strains , the HA1 protein of Victoria lineage strains showed mutations at amino acid sites of H14Q, L58P, N129S, I146V, N171D and R279K, while R48K, K88R, P108A, N116K, S150I, N165Y, D196N,N202S and S229G amino acid mutations were mainly detected in Yamagata lineage strains .The sites 116 and 129,150,165,196 and 202 located in the 120,150,160 and 190 loops,respectively,which had been previously determined to be the hotspots under positive selection .Conclusion Both Yamagata and Victoria lineages of influenza B viruses were prevalent in Qingdao and evolved continuously from 2006 to 2011 .The selective pressure that a vaccine would provide was only to virus strains belonging to the same lineage ,sug-gesting a bivalent vaccine may be better for the induction of protective immunity .