Objective To evaluate the practicability of using CRISPR/Cas9 genome editing tech-nology for inhibition of hepatitis B virus ( HBV) replication. Methods Two sgRNA targeting sites were de-signed for the S region of HBV genome. The CRISPR/Cas9 expression plasmids specific for HBV were con-structed and then transfected into a cell line expressing HBV genome(HepG2-N10). The cytotoxicity of cells transfected with different expression plasmids were detected by MTT assay. The levels of hepatitis B surface antigen ( HBsAg ) were determined by using chemiluminescent immunoassay ( CLIA ) . The expression of HBV at mRNA level was analyzed by quantitative real-time PCR ( qRT-PCR) . The qPCR was performed for the detection of extracellular and intracellular HBV DNA. The next-generation sequencing ( NGS) Illumina MiSeq Platform was used to analyze HBV genome editing. Results No significant cytotoxic effects were de-tected in HepG2-N10 cells transfected with different expression plasmids. Compared with the cells carrying pCas-Guide-GFP-Scramble, the levels of HBsAg in the supernatants of transfected cell culture harboring pCas-Guide-GFP-G1 and pCas-Guide-GFP-G2 were decreased by 24. 2% (P<0. 05) and 16. 9% (P>0. 05), respectively. The levels of HBsAg in cells transfected with pCas-Guide-GFP-G1 and pCas-Guide-GFP-G2 were respectively decreased by 16. 4% (P>0. 05) and 32. 1% (P>0. 05) as compared with that of pCas-Guide-GFP-Scramble transfected group. The expression of HBV at mRNA level was inhibited as indica-ted by the results of qRT-PCR. Moreover, the levels of extracellular HBV DNA were respectively suppressed by 23% (P>0. 05) and 35% (P<0. 05), and the levels of intracellular HBV DNA were respectively sup-pressed by 7. 2% (P>0. 05) and 18% (P>0. 05). Different types of insertion/deletion mutation were de-tected in HBV genome by high-throughput sequencing. Conclusion HBV-specific CRISPR/Cas9 system could inhibit the expression of HBV gene and the replication of virus. Therefore, the CRISPR/Cas9 genome editing technology might be used as a potential tool for the treatment of persistent HBV infection.

With the continuous research on nanotechnology, nanosensors for the detection of various biomolecular have emerged one after another. As one of the main nanosensors, quantum dots have unique optical and particle properties, and quantum dot probes for pathogen detection have been widely used. The emerging fluorescent biomarkers, quantum dot probes, have unparalleled advantages over other fluorescent probes, such as strong fluorescence signal, good photostability, long fluorescence lifetime, and large Stokes shift. They can detect the target simply, quickly, sensitively and specifically. This article provides an overview of the basic properties of quantum dots and the application foundation of quantum dot probes as detection sensors. We focus on the types and preparation method of quantum dot probes, as well as their applications in pathogen detection in recent years. Finally, the application precautions of quantum dot probes as detection sensors were summarized, and the application prospects of quantum dot probes in the field of pathogen detection were also discussed.

Objective:To establish a rapid, sensitive and specific detection method for important imported viruses based on the recombinase aided amplification (RAA) method and clustered regularly interspaced short palindromic repeats-associated protein 13a (CRISPR-Cas13a) system.Methods:In this study, we selected Japanese encephalitis virus (JEV), Yellow fever virus (YEV), West Nile virus (WNV), Middle East respiratory syndrome coronavirus (MERS-CoV)、Ebola virus (EBOV), Dengue virus (DENV), Rift Valley fever virus (RVFV), Zika virus (ZIKV) as subjects, and designed specific RAA primers and CRISPR RNA(crRNA). The sensitivity and specificity of the method were evaluated. We detected suspected clinical samples of dengue fever and compared with the fluorescent reverse transcriptase-polymerase chain reaction (RT-PCR) technology. Clinical simulation samples of the remaining seven viruses were also detected.Results:The RAA method combined with CRISPR-Cas13a can detect eight pathogens within 40-52 min at 39 ℃. The sensitivity was 1-10 copies/μl. There was no cross-reaction among eight viruses and all clinical samples could be detected by this method.Conclusions:The established RAA combined with CRISPR-Cas13a detection method can sensitively, specifically and quickly detect eight imported infectious disease pathogens.

Objective: To establish a rapid and sensitive isothermal amplification assay for the detection of human Adenovirus. Methods: Primers and probe used for recombinase polymerase amplification(RPA)were designed based on the conserved region of the adenoviruses hexon gene. After optimizing the reaction temperature and times, the products of RPA were detected by capillary electrophoresis and lateral flow dipstick(LFD). Sensitivity and specicity of the assay were evaluated. The diagnostic value of the RPA-LFD assay was verified using clinical samples which were simultaneously tested by real time PCR assay. Results: The analytical sensitivity of RPA-LFD assay was 2 copies DNA molecules per reaction and no cross reaction with other pathogens was observed. Compared with real-time PCR assay, the sensitivity, and specificity of the present assay were all 100%. Conclusions The RPA-LFD assay developed in this study has the characteristics of high specificity, sensitivity, rapid and no requirement of expensive equipment which provided a new tool for rapid detection of human adenovirus.

Objective:To establish a rapid method for detecting the activity of 2019-nCoV2.Methods:The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) detection system was screened after propidium monoazide (PMA) treatment and exposure to heat-inactivated 2019-nCoV samples, and the PMA pretreatment conditions were optimized to establish the 2019-nCoV PMA-RT-qPCR detection method . The established method was used to detect virus inactivated by different temperatures and chlorine-containing disinfectant, to evaluate its effect in detecting virus activity.Results:For the PMA-RT-qPCR assay, 200 μmol/L of PMA, 10 min of incubation time, 15 min of exposure time, and the CDC ORF1ab detection system were selected; there was no significant difference in the result of PMA-RT-qPCR and direct RT-qPCR for the active virus; the Ct values of PMA-RT-qPCR for virus inactivated by 95 ℃ and chlorine-containing disinfectant were higher than that of control groups at different dilutions; only partial dilutions of 70 ℃ and 56 ℃ heat-inactivated virus had higher Ct values than control groups. Conclusions:The established PMA-RT-qPCR for 2019-nCoV activity detection method has a good detection effect on the virus inactivated by 95 ℃ heat and chlorine disinfectant, and provides an auxiliary means for judging the infectivity of the virus in the sample.

Objective:To evaluate the compatibility laws of effective-component compatibility of Bufei Yishen formula Ⅲ (ECC-BYFⅢ) in regulating mucus hypersecretion of chronic obstructive pulmonary disease (COPD).Methods:According to the efficacy of the original Chinese medicine, the components of ECC-BYFⅢ were divided into four categories: Buqi (Ginsenoside Rh1+Astragaloside), Bushen (Icariin), Huatan (Nobiletin), and Huoxue (Paeonol). The four categories were divided into 14 groups based on the method of mathematical permutation. ① The rats were divided into control group, model group, ECC-BYFⅢ, and different components compatibility groups according to the random number table, totaling 17 groups. COPD rat model in stable phase was established by cigarette smoke exposure combined with repeated bacterial infections. The corresponding drugs were given by gavage at the 9th week of modeling, and the samples were collected at the end of the 16th week. The levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitors of metalloproteinase 1 (TIMP-1) in serum and bronchoalveolar lavage fluid (BALF), and the levels of mucin (MUC) 5AC in lung tissue and BALF were detected by enzyme linked immunosorbent assay (ELISA). ② Human lung epithelial cells BEAS-2B were divided into blank group, model group, and different components compatibility groups. Hypoxia-induced mucus hypersecretion model of human lung epithelial cells BEAS-2B was established 4 hours after corresponding drug pretreatment. The mRNA expressions of MUC5AC, MUC5B, and MUC1 were detected by quantitative polymerase chain reaction (PCR). The mucus secretion indexes of rats and BEAS-2B cells were evaluated by Region (R) value comprehensive evaluation method.Results:① Compared with the control group, MMP-9 in serum and BALF from the model group were significantly increased, the level of TIMP-1 was significantly decreased, and MUC5AC in lung tissue and BALF were significantly increased. The results of R value comprehensive evaluation showed that except for the Buqi and Bushen groups, ECC-BYFⅢ and other components compatibility groups significantly corrected mucus hypersecretion in COPD rats, ECC-BYFⅢ, Bushen Quxie, Fuzheng Huatan, and Quxie groups were much better (R values were 2.15±0.42, 2.11±0.23, 2.16±0.23 and 2.16±0.55, respectively), compared with the model group (R value: 3.00±0.00), the differences were statistically significant (all P < 0.05). ② Compared with the blank group, the mRNA expressions of MUC5AC, MUC5B, and MUC1 increased in the model group. But different components compatibility groups had no significant effects on the mucus secretion of BEAS-2B cells. ③ The comprehensive evaluation results of R value about each in vivo and in vitro index showed that ECC-BYFⅢ, Huoxue, Quxie, Bushen Huoxue, Fuzheng Huatan, Buqi Quxie groups significantly corrected the mucus hypersecretion (R values were 2.30±0.43, 2.33±0.44, 2.12±0.68, 2.27±0.64, 2.24±0.27 and 2.29±0.47, respectively), compared with the model group (R value: 3.00±0.00), the difference was statistically significant (all P < 0.01). The order was: Quxie > Fuzheng Huatan > Bushen Huoxue > Buqi Quxie > ECC-BYFⅢ > Huoxue. Conclusions:Different components compatibility of ECC-BYFⅢ had different effects on COPD mucus secretion. The components containing Huatan (Nobiletin) or Huoxue (Paeonol) showed a better inhibitory effect on mucus secretion.

Objective:The entire genome sequences of 25 novel coronaviruses in Jiangsu province were analyzed and their evolutionary characteristics were studied.Methods:High-throughput sequencing was used to sequence the throat swab samples from confirmed cases. Single nucleotide polymorphisms were analyzed using CLC Genomics Workbench 12.0 software. Evolution characteristics were analyzed by MEGA 5.1.Results:A total of 52 single-base substitution mutations were detected in 25 strains. Phylogenetic analysis showed 25 stains were clustered into two clades. Viruses in clade 1 contain 8 682 and 28 144 CT SNP links. While viruses in clade 2 contain mutations in those two bases, i. e., 8 682 (ORF1ab: C8 517T, synonymous mutation) and 28 144 (ORF8: T251C, L84S). Among clade 2, five stains subclustered into one group based on SNP links in 24 034 (S: C2 472T, synonymous mutation), 26 729 (M: T207C, synonymous mutation), and 28 077 (ORF8: G184C, V62 L). There were no significant differences in the distribution of different clades/subclusters in the population and the disease types.Conclusions:We have found some SNPs occurred in new coronaviruses. The effects of different SNPs on virus transmission and pathogenicity need to be further studied.

Objective To explore the interventional mechanism of Bufei Yishen formula on chronic obstructive pulmonary disease from pathway level.Methods Macrophage inflammatory model was established by LPS stimulation.Based on gene set enrichment analysis(GSEA)method,macrophage inflammation related pathways were screened,and normalized enrichment score(NES)was used to identify pathways that were reversed by traditional Chinese medicine treatment,revealing the interventional mechanism of Bufei Yishen formula and its compatibility.Results The NES of Bufei Yishen formula was-1377.23,among which the NES of Bushen compatibility was-485.07,that of Huoxue was-351.86,Huatan was-303.71,and Yiqi was-236.59.There were 213 significantly disturbed pathways reversed after the intervention of Bufei Yishen formula,among which there were 184 reversed pathways for Huoxue compatibility,147 reversed pathways for Bushen,134 reversed pathways for Huatan,133 reversed pathways for Yiqi,and the reversal rate was 75.41%,60.25%,54.92%,54.51%,respectively.90 pathways,including TGF-β production,were significantly reversed in the four compatibilities.Positive regulation of cytokine production involved in inflammatory response etc were specifically reversed pathways for compatibility.Conclusion The intensity of Bufei Yishen formula that reversed macrophage-inflammatory related pathways was in order of Bushen,Huoxue,Huatan and Yiqi compatibility.And the number of pathways that could be reversed by the compatibility of Bufei Yishen formula was Huoxue,Bushen,Huatan and Yiqi.Bufei Yishen formula could regulate the common and specific reversal pathways of the compatibilities to intervene the inflammatory response.

Objective:To explore the effect of significant variation in non-structural protein 1 (NSP1) of 2019 novel coronavirus (2019-nCoV) on binding to 5′UTR, and to provide clues for the development of antiviral drugs and vaccines.Methods:The bioinformatics analysis of 2019-nCoV genome database was conducted to select the amino acid variation sites (T12A, R124L, N128I, K141A, GHVMV82-86DEL and KSF141-143DEL) that may affect the structure of NSP1 and the ability binding to 5′UTR. PSIPRED online tool was used to analyze the secondary structure of the variants, mCSM-NA was used to predict their binding ability to RNA, and DynaMut webserver was used to analyze the influence of variants on protein stability. The variant plasmids were constructed and transfected into HEK-293T cells. The dual luciferase reporter gene assay and RNA binding protein immunoprecipitation (RIP) assay were used to detect the binding ability of the NSP1 variant for viral 5′UTR.Results:Bioinformatics analysis predicted that except for R124L mutation, the other five variants could change the secondary structure of protein, and the mutations of T12A, R124L, N128I and K141A could reduce the binding ability of RNA, while the mutations of T12A, R124L and N128I reduced the stability of protein. The experimental results showed that R124L, N128I, GHVMV82-86DEL and KSF141-143DEL significantly weakened the binding ability of NSP1 to 5′UTR.Conclusions:Some mutations or deletion of NSP1 amino acids could change the secondary structure and significantly weaken the binding ability of NSP1 to the 5′UTR, suggesting that the pathogenicity of the virus may be changed, which could provide a theoretical basis for the development of antiviral drugs and vaccines.

Objective: To analyze the clinical manifestations and results of etiological examinations of 17 elderly patients with influenza A (H1N1) viral pneumonia, and to understand the clinical features of pneumonia and molecular characteristics of influenza A (H1N1) virus infection in the elderly. Methods: The elderly patients with pneumonia who were hospitalized in the Department of Respiratory Diseases of Nanjing First Hospital from January 2018 to March were enrolled. The cases were confirmed by nucleic acid examination for influenza virus and the clinical data were collected. After the amplification of the whole genome of influenza virus, the high throughput sequencing and bioinformatics analysis were performed. Results: The mean age of the 17 enrolled patients was 73.8±10.8. All of them had at least 1 underlying disease, and 7 cases had co-infection. Respiratory symptoms and fever were the most prominent clinical manifestations. Lesions in both lungs were found in 76.5% of the patients. The result of high throughput sequencing showed that all the viruses were highly homologous to the vaccine strain, and the HA gene belonged to the 6B.1 subgroup. Furthermore, three variations of antigenic locus (H138Y, S74R and S164T in HA) and a drug-resistant variation (H275Y in NA) were detected in the circulating strains. Conclusions Elderly patients with influenza A (H1N1) virus pneumonia often have underlying diseases and are prone to have co-infection. The molecular characteristics of the virus and the variation of key amino acid loci should be closely monitored in order to provide evidence for epidemic prevention and clinical antiviral treatment.