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Objective:To analyze the genetic variation characteristics of the HA gene of influenza A virus (H3N2) in Guizhou province from 2017 to 2019. Methods:Twenty strains of influenza A virus (H3N2) were randomly selected from 10 network laboratories in Guizhou province for RNA extraction. Reverse transcriptase-polymerase chain reaction and sequencing were performed. The products were analyzed using bioinformatics software.Results:The nucleotide homology of the HA gene of the 20 strains was 97.7%-100%, which was highly homologous to the vaccine strains A/Hong-Kong/4801/2014 recommended by WHO in 2017 and A/Singapore-INFIMH/16-0019/2016 recommended by WHO in 2018, but they were significantly different from the vaccine strain A/Kansas/14/2017 recommended by WHO in 2019. Genetic analysis showed that the 20 strains were divided into two branches, and the strains that were prevalent in 2019 were located in different branches, with marked genetic differences. Key site analysis showed mutations in antigenic determinants A, B, C, and E and mutations in the anterior and posterior walls of receptor binding sites. Key site analysis also showed that there was an increase in the number of glycosylation sites compared with the vaccine strains prevalent in the same year. Genetic distance, antigen sites, and glycosylation sites were slightly different between virus strains prevalent in 2017-2018 and virus strains prevalent in 2019. Conclusion:The HA gene of the influenza A virus subtype H3N2 in Guizhou province from 2017 to 2019 showed heterogeneity and gene mutation, especially in 2019. Therefore, close monitoring of the genetic evolution of the influenza A virus subtype H3N2 is necessary.
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A 55-year-old male patient presented with plaques on the face for more than 20 years,and no immunodeficiency diseases were diagnosed.Skin examination showed large areas of pink plaques on the nose,bilateral cheeks and upper oral lips with slight desquamation,verrucous hyperplasia on the dorsal area of the nose,and a bean-sized verrucous protuberance on the tip of the nose.Histopathological examination of the skin lesions revealed pseudoepitheliomatous hyperplasia in the epidermis and hyphae-like structures in the stratum corneum.Moreover,there was diffuse infiltration of inflammatory cells in the dermis,which mainly included neutrophils,lymphocytes,histiocytes and multinucleated giant cells.Periodic acid-Schiff (PAS)-positive spore-like structures were observed in the multinucleated giant cells.Culture of the lesional tissues on Sabouraud dextrose agar (SDA) medium showed grey-brown villous colonies.Microculture on the potato dextrose agar (PDA) medium yielded dark septate hyphae and pycnidia filled with a large number of spores.Microsphaeropsis arundinis was identified by fungal molecular biological techniques.The patient was diagnosed with cutaneous phaeohyphomycosis caused by Microsphaeropsis arundinis.The patient was treated with CO2 laser for the removal of verrucous protuberance on the tip of the nose,and oral itraconazole capsules at a dose of 200 mg twice a day.After 3-month treatment,the skin lesions subsided and the drug was withdrew.During 6-month follow-up,no relapse occurred.
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Objective To sequence and analyze the envelope (E) gene of type Ⅰ dengue virus isolated from Guangzhou in 2009 for tracing the infection source. Methods The serum samples were collected from patients diagnosed with dengue fever in Guangzhou area during 2009. Dengue virus was isolated and cultured in C6/36 cells.The whole length of E gene was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and then sequenced. The phylogenetic tree was drawn by neighbor-joining method. The bioinformatics analysis was performed by combining the phylogenetic information and the epidemiology data. Results Four strains of type Ⅰ dengue virus were isolated from 19 samples. E gene of these strains was amplified and sequenced. The phylogenetic analysis showed that 09/GZ/9104 strain and 09/GZ/9236 strain had identical nucleotide sequence and fell within the American/African group, 09/GZ/11534 stain and 09/GZ/11562 strain had similar sequence homology and fell within the Asian group. Conclusion The typeⅠdengue viruses in Guangzhou area in 2009 are imported, which belong to two genotypes and may come from two independent origins respectively.
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Objective To analyze nucleic acid sequence homology of the 6 kb(pYC) plasmid of Yersina. pestis (Y. pestis) isolated from Yurman by searching GenBank. Method The search of sequence similarity was accomplished with BLAST. Results The pYC plasmid sequence had high homology with some genes in nueleotide sequence, such as: 97.1% homology with Shigella sonnei pKYM, 92.1% homology with Haemophilus influenzae(H. influenzae) gene, Salmonella typhi (S. typhi) gene LT2 and plMVSI with 88.2% and 87.2% of homology respectively, Escherichia coli(E, coli) O157:H7 and K-12, ECOR31 with 81.4%, 81.4% and 84.7% of homology respectively. This plasmid ORFs could code for some proteins which were similar with others in GenBank, such as: ORFi and H. paragallinarum replication protein B(47.2%), ORF4 and E. coli hypothetical protein(52.7%), ORF5 and Y. pseudotuberculosis Tile (48.3%), ORF6 and E. coil Pilx5/VirB5-1ike protein (42.3%), Y. enterocolitica TriD protein(38.5%), ORFIO and S. typhimurium LT2, E. coli O157:H7 hypothetical protein(83.1% and 81.9%, respectively), ORF11 and E. coli, damage-inducible protein J(81.4%). Conclusions The pYC plasmid sequence has high homology with a few bacterial genes of Enterobacteriaceac. This plasmid may code for some proteins that are similar with hypothetical protein, damnge-indncible protein, TriD and TilE protein, Pilx5/VirB5-hke protein of Escherichia or Yersinia.
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Objective To analyze the HEV genetic structure and nucleotide homology isolated from sporadic acute hepatitis E in Changchun.Methods HEV RNA was detected with reverse transcription nested polymerase(RT-nPCR) and sequenced by automatic sequenator.Results The length of acquisitive HEV-CCC220 was 7193 bp coding 2397 amino acid.The gene of HEV-CCC220 was composed of 5'-UTR(nt 1-9),3'UTR(nt 7152-7193) and three open reading frames(ORFs).Its homology with HEV IV was obviously higher than that with HEV(I-III.) The whole genome sequence nucleotide homology was 83.2%-85.0%,85.0%-93.9% and 80.6%-86.7% as compared with 300nt and 98nt partial nucleotide sequence of ORF2.The homology comparison of various areas and various lengths of nucleotide was different.Conclusion The HEV-ccc220,which sporadically happened in Changchun,is the subtype IV of HEV.The 300nt of ORF2 can replace the whole gene order to perform genotype analysis of HEV.
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Objects To observe the TEM gene characteristic of Acinetinbacter lwoffi strains which were resistant to most kind of antibiotics and to compare their sequences with that of Escherichia coli Methods Two strains of A lwoffi, JN18 and JN70,were isolated from sputum of patients′ who suffered from respiratory infection TEM, SHV, OXA, IMP and CTX M genes were tested by PCR TEM sequences of JN18 and JN70 were detected by ABI automated sequencer and were analysed by DNAStar software to compare the differences with E coli TEM genes that had been published in GenBank Results Detected sequences of A lwoffi JN18 and JN70 strains were 1012 bp and 887 bp, respectively They coded regions of 832 bp and 772 bp for TEM of the two strains that were 98 2% identical In other hand, there were 14 pair bases differently in TEM regions The TEM sequence of JN18 was 98 72% identical to that of E coli TEM on the average, which was over 99% to TEM1D, TEM 70, TEM 76, TEM 77 and TEM 95 of E coli The divergence of TEM genes was 1 26 between A lwoffi JN18 strains and E coli JN70 strain had higher identity (98 93%), which reached 99 5% to TEM1D, TEM1F and TEM84 of E coli As JN18 strain, TEM gene of JN70 had very small divergence (1 06 ) with E coli Conclusion JN18 and JN70 strains of A lwoffi isolated from patients′respiratory tract in Jinan shared most of sequences with E coli TEM76 and 84 However, there were many mutant sites in them