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Objective@#To understand the pathogen spectrum of severe hand, foot and mouth disease (HFMD), and analyze the genetic characteristics of enterovirus A71(EV-A71) in Xianyang in 2018.@*Methods@#Totally 67 specimens of severe cases of HFMD were collected. Enteroviruses associated with HFMD were detected by real-time PCR and the genotypes of enteroviruses were identified by VP4 region of enteroviruses. The nucleotide and amino acid sequences of VP1 region of EV-A71 were analyzed.@*Results@#A total of 30 samples were positive for enterovirus among samples from 67 severe cases with HFMD, including 9 cases of EV-A71, 11 cases of coxsackievirus A6 (CV-A6), 5 cases of coxsackievirus A16 (CV-A16), 2 cases of coxsackievirus A10 (CV-A10) and 2 cases of coxsackievirus A4 (CV-A4). The nucleotide and amino acid homologies of EV-A71 among 4 strains reached 96.7%-99.9% and 99.3%-100% respectively. The 4 strains of EV-A71 belonged to C4a subtypes by phylogenetic analysis. The six amino acid composite model was KADSTV in 4 strains of EV-A71. The EF region and GH region in antigenic determinants of 4 strains of EV-A71 kept consistent with representative reference strains, however, the EV-A71 SZK222 and SZK497 strains developed mutation at site 93 (I93V) of BC loop region.@*Conclusions@#EV-A71 and CV-A6 are major agents of severe HFMD in Xianyang in 2018. The genotype of EV-A71 belonged to C4a subtype and the VP1 gene did not show more mutations.
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Objective@#The genetic characteristics of the human adenovirus type 53 (HAdV-53) strains isolated from Taiyuan city of Shanxi Province were studied to obtain the baseline data of their molecular characteristics.@*Methods@#Conjunctival swabs (n=79) were collected from epidemic keratoconjunctivitis (EKC) patients in Shanxi eye Hospital in 2016, and five HAdV-53 strains were obtained after virus isolation and identification based on the three major capsid genes sequences including Penton base, Hexon and Fiber gene. And the corresponding sequences of global epidemic HAdV-53 strains and the strains with the same genetic origin as HAdV-53 were also downloaded from GenBank database, and then the three gene database were established, respectively. With the database, phylogenetic tree was constructed, and the genetic and molecular evolutionary characteristics were analyzed with bioinformatics software.@*Results@#Five HAdV-53 strains in Shanxi Province in 2016 showed high consistency with the HAdV-53 strains prevalent in other countries in 1996-2014 (>99.8%). All HAdV-53 strains were in the same evolutionary branch with their recombinant source genotypes (HAdV-37 and HAdV-8) in Penton base and Fiber gene, respectively, and maintained a high degree of consistency in gene sequences. In Hexon gene, HAdV-53 strains were more closed to its recombinant source genotype HAdV-22, the nucleotide and amino acid sequences between two types were highly homologous, while HAdV-53 and HAdV-22 belonged to different evolutionary branches, and the evolution rate of HAdV-53 based on Hexon gene was 3.51×10-5 substitution/site/year.@*Conclusion@#HAdV-53 has become an important new ocular infectious pathogen of Taiyuan. HAdV-53 strain are relatively conservative and stable based on Penton base, Hexon, and Fiber gene.
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Objective To investigate the genetic characteristics and mutations in hemagglutinin ( HA) genes of influenza A subtype H3N2 viruses isolated in Fujian province during 2014—2016. Methods HA gene fragments of 44 randomly selected influenza A (H3N2) viruses were amplified by RT-PCR and then sequenced by Sanger sequencing. Obtained sequences were analyzed by bioinformatics software and on-line websites. Results Pair-wise similarity among HA genes of the 44 strains was between 97. 3%-100. 0% at nucleotide level. The average variations between epidemic strains and corresponding vaccine strains in the year of 2014, 2015 and 2016 were 0. 012, 0. 008 and 0. 009, respectively. The genotype of epidemic strains in 2014 was 3C. 3a rather than 3C. 1 of the vaccine strain. Notably, variations at some antigenic sites, re-ceptor binding sites ( RBSs) and N-Glycosylation sites were identified despite the fact that the genotypes were identical between epidemic and vaccine strains in 2015 and 2016. Conclusion Variations at the HA genes of influenza A (H3N2) viruses in Fujian province occurred during the year of 2014—2016, reflecting the ability of circulating strains to escape the vaccine-induced immunity. Sustainable influenza surveillance and prompt identification of viral variants would benefit influenza prevention and control.
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OBJECTIVE@#This study aimed to investigate the clinical phenotype and genetic characteristics of Chinese families with Van der Woude syndrome (VWS).@*METHODS@#Clinical manifestations between 14 families and within each family were recorded. Possible inheritance modes and pathogenic genes were analyzed. Phenotypic distribution and gene frequencies were calculated.@*RESULTS@#Of the pedigrees investigated, an autosomal dominant inheritance pattern was suggested. All patients had typical symptoms. The pathogenic gene was interferon regulatory factor 6 (IRF6). Phenotypic distribution frequencies were as follows: lip pits (91.9%), cleft lip and/or palate (73.0%), and hyperdontia (8.1%). There were significant differences in clinical phenotypes among individuals of different families and individuals of the same family.@*CONCLUSIONS@#VWS in a Chinese population was dominantly inherited with high penetrance and variable expressivity. The pathogenic gene was IRF6. VWS in a Chinese population was genotyped as VWS1.
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Humanos , Anomalías Múltiples , Genética , Labio Leporino , Genética , Fisura del Paladar , Genética , Quistes , Genética , Factores Reguladores del Interferón , Genética , Labio , Anomalías Congénitas , Mutación , Linaje , SíndromeRESUMEN
Objective To analyze the genetic characteristics of echovirus type 25( Echo25) strains isolated from patients with viral encephalitis in Longyan city. Methods Cerebrospinal fluid(CSF) specimens were collected from hospitalized patients with viral encephalitis or central nervous system infection in Longyan,2012. Enteroviruses(EV)were isolated from the specimens and then identified. Four strains of Echo25 were screened out by using serum neutralization test. Coding sequence of the VP1 region of the 4 Echo25 strains were amplified by RT-PCR and then sequenced. A phylogenetic tree was constructed to ana-lyze the nucleotide sequence homology between those sequences and the sequences of reference Echo25 strains available in the GenBank database. Results The VP1 nucleotide sequences of Echo25 strains isola-ted in Longyan were 498 bp in length,encoding 166 amino acid residues. The homology analysis showed that the VP1 nucleotide sequences of 3 strains were identical,sharing 97% homology in nucleotide with the rest strain. The Echo25 strains isolated in Longyan were highly similar to KJ957190( Beijing,2010)and HM031189(Henan,2008)strains. Phylogenetic analysis revealed that the Echo25 strains isolated in Longyan belonged to genotype B1. Conclusion Echo25 was one of the pathogens causing viral encephalitis in Longyan in 2012 and different transmission chains of Echo25 had emerged. This study indicates that it is necessary to strengthen the surveillance for EV and understand the genetic variation of the Echo25 for provi-ding better supportive evidences for the prevention and control of related diseases.
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Objective To understand the genetic variations of influenza B virus outbreaks in Guizhou province in 2016,and to compare the matching situation of outbreak epidemic strains with the vaccine strains recommended by WHO and representative strains in China.Methods The haemagglutinin HA1 gene of 8 strains isolated from two episodes of influenza B virus outbreaks in Tongren area was amplified and sequenced.The sequencing products were analyzed by bioinformatics software DNAStar. Results The two episodes of influenza outbreaks were both caused by influenza B Victoria lineage virus (BV).The homologies of the isolated strains were 99.8%—100.0% in nucleotide and 99.5 %—100.0%in amino acid.Mutation was only detected at 274 site in some strains.Compared with reference strain B/Victoria/2/87,the homologies were 91 .8%—92.0% and 91 .5 %—92.0%,respectively.Mutations developed at 17 amino acid sites,among which,I143V,V163I and V201I site were associated with the main antigenic determinant area B,C and D.Compared with previous vaccine strain B/Brisbane/60/2008, the homologies were 98.2%—98.3% and 98.5 %—99.0%,respectively,and mutations were detected at 3 sites.Mutations at I143V and N155D were detected in all 8 strains and at T247I in some strains.The mutation of I143V was associated with antigenic determinant area B.Compared with the representative strain B/Chongqing-Yuzhong/1384/2010,the homologies were 96.7%—96.8% and 97.0%—97.5 %, respectively.A total of 6 sites developed mutations,among which,5 sites were P84L,I143V,N155D, V172I and T223N mutations.The mutation of T247I was detected in some strains,and I143V was associated with area B.Compared with the epidemic strain in Guizhou in 2016,the homologies were 99.8%—100.0% and 99.5 %—100.0%,respectively.Mutation was only detected at site 247 in some strains and was not associated with the main antigenic determinant area.Conclusions The two episodes of influenza outbreaks in Guizhou are caused by the same BV lineage epidemic virus strain.Haemagglutinin gene of BV lineage virus is constantly changing.However,there is no new mutation emerged at important site.Compared with previous influenza vaccine strain B/Brisbane/60/2008 recommended by WHO,BV lineage virus is well matched and could provide a positive protection effect.
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Objective To study the genetic characteristics of avian influenza virus strain A/Zhejiang/16/2006 which was isolated from the case first reported in Zhejiang province.Methods Complete genome of A/Zhejiang/16/2006 including eight segments were sequenced and compared on the genetic homogeneity with sequences of the similar strains provided through domestic and overseas sources.Results There were 11 amino acids showing differences on HA between A/Zhejiang/16/2006 and the H5N1 isolates of neighboring countries,but these differences had not affected the stability of glycosylation sites.In the NA region,20 amino acids located in the 49th to 68th position were found absent in the isolates obtained after 1997.Eight segments of H5N1 isolates,circulating in the mainland of China in the recent years,formed a separate branch compared to the strains in neighboring countries and there was also obviously different from the strains isolated in Hong Kong and Guangzhou in 1996 and 1997.However,several Chinese strains were close to the Hong Kong strains isolated in 1997 but diffferent from the current strains in the phylogenetic tree.Conclusion The influenza virus strain A/Zhejiang/16/2006 formed a separate branch with the strains isolated in the mainland of China in the past years but it presented an obvious difference with the isolates from the neighboring countries.
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Twelve strains of V. vulnificus isolated from clinical specimens in 2002~2004 in Jeollado province were determined for their biologic groups, serotypes, presence of vvhA (hemolysin/cytolysin) gene, DNA sequence, and PFGE patterns of NotI-restricted genomic DNA. The following results were obtained. All 12 isolates were biogroup 1, and API 20E profiles were: 5146105 for 5 (41.7%) isolates, and 5148125 for 2 isolates with sucrose fermentation. Ten (83.3%) of the 12 isolates was V. vulnificus serotype O4A, and two sucrose-fermenting isolates belonged to serotype O2. Alleles of cytolysin-hemolysin gene were detected in all 12 isolates. The nucleotide sequences of vvhA genes from strains WKHC 212 and WKHC 221 showed 94~97% similarity compared with those from previously reported 7 strains, YJ016, CMCP6, L-180, CDC B3547, IF Vv10, CIP 75.4T and CNRVC 970121. PFGE of NotI-restricted genomic DNA from the 12 isolates showed approximately 48.5 to 873-kb fragments and they were clustered to five (A to E) patterns. Two sucrose-fermenting isolates belonged to pattern D with 95% similarity with each other. Two strains isolated from two different patients had two identical patterns C and D. It is concluded that sucrose-fermenting strains also exist among clinical isolates of V. vulnificus in Korea, and they can be identified by using API 20E system, and by detecting vvhA gene. DNA sequences and PFGE pattern of NotI-restricted genomic DNA suggested that the two sucrose-fermenting isolates belonged to an identical clone, and two strains each isolated from two different patients belonged to two identical clones.