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Objective:To report the first case of sever fever with thrombocytopenia syndrome caused by severe fever with thrombocytopenia syndrome virus (SFTSV) in Puyang city, and to study the epidemiological and molecular characteristics of S, M, L fragments of the SFTSV isolate.Methods:The epidemiological characteristics of this case was analyzed with epidemiological methods. SFTSV was isolated from the patient′s serum sample. Nucleic acid of SFTSV was extracted and detected by fluorescent RT-PCR. A multiplex PCR method was constructed to amplify the nucleic acid sequence of the virus. whole-genome sequencing was performed on the next-generation sequencing platform. MEGA11 and DNAStar was used for homology analysis and a phylogenetic tree was constructed.Results:Epidemiological investigation showed that the patient and his close contacts had no history of travel or tick bite within 14 d, but had a history of fieldwork. The patient′s serum sample was positive for SFTSV nucleic acid. Genetic analysis showed that the S, M, L gene fragments of the first SFTSV isolate in Puyang belonged to genotype E. This isolate shared 94.8%-99.6%, 94.0%-99.8% and 95.7%-99.7% nucleotide sequence homology with the representative strains acquired from GeneBank in S, M, L gene fragments, respectively.Conclusions:This case was the first case of SFTSV-caused severe fever with thrombocytopenia syndrome in Puyang. The SFTSV isolate shared a close homology with domestic isolates, but its genotype was significantly different from the SFTSV strains isolated in Henan in recent years, indicating that it might an imported case from other places in Henan Province or Hubei Province. Disease monitoring and professional training for medical personnel should be strengthened and more attention should be paid to the evolution and mutation of SFTSV.
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Objective:To analyze the epidemiological characteristics and spatiotemporal characteristics of human brucellosis in Henan Province.Methods:Data of human brucellosis in Henan Province from 2005 to 2021 were collected through the China Disease Prevention and Control Information System, and a descriptive epidemiological method was used to analyze the epidemic profile of brucellosis in Henan Province and the three distribution characteristics. Global and local spatial autocorrelation were used to analyze the spatial distribution and the hot spots of brucellosis in Henan Province, respectively, and spatiotemporal scanning was used to analyze the spatiotemporal clustering regions of brucellosis in Henan Province.Results:A total of 39 862 brucellosis cases were reported in Henan Province from 2005 to 2021, with an average annual incidence of 2.44/100 000, and the number of cases showed an overall increasing trend each year (χ 2trend = 11 127.85, P = 0.001). The onset months were mainly concentrated from March to July, accounting for 59.00% (23 517/39 862), with May as the peak (5 478 cases). Cases of brucellosis were reported in 157 counties (cities, districts) of the province. The ratio of male to female was 2.52∶1.00 (28 542/11 320). Farmers were the main occupation, with 32 985 cases (82.75%). The age of onset was mainly 45 to 65 years old, with 20 226 cases (50.74%). The global spatial autocorrelation analysis showed that the global Moran's I was > 0, Z > 1.96, and P < 0.05 in all years except 2006 - 2008, showing spatial clustering. Further local spatial autocorrelation analysis was performed, and high-high and low-low clustering areas existed in 2012 - 2021 ( P < 0.01). Spatiotemporal scanning analysis showed that there was one spatiotemporal cluster in the high incidence area and two spatiotemporal clusters in the low incidence area. The high incidence cluster was centered in Neixiang County, covering 48 counties (cities, districts) including Song County and Ruzhou City, and the aggregation time was from 2014 to 2021. The two low incidence clusters were centered in Yongcheng City and Boai County, covering 58 and 18 counties (cities, districts), respectively, and the aggregation time was 2016 - 2021 and 2005 - 2012, respectively. Conclusion:The overall incidence of brucellosis in Henan Province is on the rise from 2005 to 2021, with middle-aged and elderly male farmers as the main affected population, and there are spatiotemporal clusters of brucellosis in Henan Province.
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Objective:To establish a sequencing method for the genome of severe fever with thrombocytopenia syndrome virus (SFTSV) based on next-generation sequencing (NGS).Methods:SFTSV RNA was extracted from serum samples of patients with severe fever with thrombocytopenia syndrome. SFTSV-specific primers were designed using Primer 5.0 software. A multiplex PCR method was constructed and used to amplify the nucleotide sequence of SFTSV. Whole-genome sequencing was performed on the NGS platform.Results:The whole genes of SFTSV isolates in 28 serum samples were amplified by the multiplex PCR with a coverage over 94%. Sequencing and phylogenetic analysis of those strains revealed that the predominant strains ( n=20) belonged to genotype A, followed by genotypes B ( n=4) and E ( n=3). Conclusions:A high-throughput sequencing method for SFTSV based on multiplex PCR was established in this study. This method was characterized by high specificity and good quality and could improve the sequencing efficiency.
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In spite of the successful development of effective countermeasures against Covid-19, variants have and will continue to emerge that could compromise the efficacy of currently approved neutralizing antibodies and vaccines. Consequently, novel and more efficacious agents are urgently needed. We have developed a bispecific antibody, 2022, consisting of two antibodies, 2F8 and VHH18. 2F8 was isolated from our proprietary fully synthetic human IDEAL (Intelligently Designed and Engineered Antibody Library)-VH/VL library and VHH18 is a single domain antibody isolated from IDEAL-nanobody library. 2022 was constructed by attaching VHH18 to the C-terminal of Fc of 2F8. 2022 binds two non-overlapping epitopes simultaneously on the RBD of the SARS-CoV-2 spike protein and blocks the binding of RBD to human angiotensin-converting enzyme 2 (ACE2). 2022 potently neutralizes SARS-CoV-2 and all of the variants tested in both pseudovirus and live virus assays, including variants carrying mutations known to resist neutralizing antibodies approved under EUA and that reduce the protection efficiency of current effective vaccines. The half-maximum inhibitory concentration (IC50) of 2022 is 270 pM, 30 pM, 20 pM, and 1 pM, for wild-type, alpha, beta, and delta pseudovirus, respectively. In the live virus assay, 2022 has an IC50 of 26.4 pM, 13.3 pM, and 88.6 pM, for wild-type, beta, and delta live virus, respectively. In a mouse model of SARS-CoV-2, 2022 showed strong prophylactic and therapeutic effects. A single administration of 2022 intranasal (i.n.) or intraperitoneal (i.p.) 24 hours before virus challenge completely protected all mice from bodyweight loss, as compared with up to 20% loss of bodyweight in placebo treated mice. In addition, the lung viral titers were undetectable (FRNT assay) in all mice treated with 2022 either prophylactically or therapeutically, as compared with around 1x105 pfu/g lung tissue in placebo treated mice. In summary, bispecific antibody 2022 showed potent binding and neutralizing activity across a variety of SARS-CoV-2 variants and could be an attractive weapon to combat the ongoing waves of the COVID-19 pandemic propagated mainly by variants, especially, the much more contagious delta variant.
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Objective:To clarify whether the signal peptide of human nerve growth factor can mediate secretory expression of beta-endorphin and whether there is difference between the efficiency of signal peptides from human and mouse nerve growth factor.Methods: Two kinds of eukaryotic vectors containing human or mouse signal sequence-mediated secretory expression of beta-endorphin were constructed.The culture supernatant and cells were collected 48 h after NIH3T3 cells were transfected by the two kinds of vectors,and the cover slips with single-layer cells was prepared.The concentration of beta-endorphin in the culture was determined by radio-immunoassay.The total RNA was extracted from cells and mRNA from fusion genes was assayed by RT-PCR.Cells on cover slips were subjected to immunofluorescence staining.Results: RT-PCR showed that the fusion genes were expressed in NIH3T3 cells;the expression of beta-endorphin was mainly in the cytoplasm of NIH3T3 cells.The concentrations of beta-endorphin in the supernatants 48 h after transfection with pcDNA3.1-hEP and pcDNA3.1-mEP were(280.33?24.16) pg/ml and(191.04?7.96) pg/ml(P
