Rabies virus viability in vitro / 中华微生物学和免疫学杂志

Objective:To investigate the in vitro viability of rabies virus in tissues and body fluid samples. Methods:The viability of rabies virus in tissues and suspensions was analyzed by virus titer determination method, direct immunofluorescence, RT-PCR and laboratory techniques for virus isolation.Results:With the increase of temperature, the viability of rabies virus in brain tissues and suspensions decreased gradually. Rabies virus lost infectivity after 30 min at 56℃, but remained viable in tissues for 7 d at 37℃. The virus showed no viability after 1 h at pH9.6. The rabies virus in suspensions could be completely inactivated after the stimulation with ethanol at a final concentration above 30%, sodium hypochlorite above 500 mg/L or benzalkonium bromide above 100 mg/L for 3 min. It was found that 80% acetone had the strongest inactivation effect on rabies virus in tissues, and no virus could be isolated after soaking for 4 h.Conclusions:Rabies virus was not tolerant to high temperature and relatively stable in the environment with pH6.8-7.4. Common disinfectants could kill the virus. This study provided detailed data about the viability of rabies virus in vitro, which would be conducive to the prevention and control of rabies.

In vitro inhibitory effects of resveratrol on rabies virus / 中华微生物学和免疫学杂志

Objective:To analyze the in vitro inhibitory effects of resveratrol on rabies virus. Methods:The challenge virus standard (CVS)-11 strain of rabies virus and BHK-21 cells were used to establish the infection model. In vitro inhibitory effects of resveratrol on rabies virus were analyzed at different stages of infection by direct immunofluorescence and cell fluorescence focus unit assay. Results:Without affecting cell growth, resveratrol could block the adsorption of virus, interfere with the entry of virus into cells and inhibit virus proliferation in a concentration-dependent manner. The inhibition rate could reach up to about 95%. The results of co-incubation experiment showed that 40 μmol/L resveratrol could directly kill the virus.Conclusions:This study indicated that resveratrol inhibited the activity of rabies virus in a concentration-dependent manner.

Codon optimization improves the expression of nucleoprotein of rabies virus CTN-1 strain in E. coli / 中华微生物学和免疫学杂志

Objective:To obtain the high-efficiency expression of the biological active rabies virus nucleoprotein in the prokaryotic expression system.Methods:This experiment uses codon optimization technology to re-encode the nucleoprotein gene of rabies virus CTN-1 strain, artificially synthesize the full-length gene and clone it into pET-43.1a prokaryotic expression vector, induced expression in BL21 (DE3) strain of Escherichia coli( E. coli), and used Western blot to detect its reactogenicity. Results:The results showed that after induction, SDS-PAGE electrophoresis analysis showed that an obvious expression band appeared at a molecular weight of 50×10 3, which was consistent with the expected protein band size. Among them, the E. coli concentration A600 is about 0.5, and the expression yield is the highest (about 32.3%) when induced at 37℃ for 5 h. Nucleoprotein expression product is mainly inclusion body when it is expressed in large quantities. After purification by Ni 2+ chelating chromatography, the purity of the target protein can reach over 95%. The purified product was identified by Western blot and positively reacted with the sera of mice immunized with rabies vaccine, indicating that the prokaryotic expression of the CTN-1 strain nucleoprotein has biological activity. Conclusions:This experiment successfully established a high-efficiency expression method for the nucleoprotein of the CTN-1 strain in the prokaryotic expression system, and obtained high-purity target protein, which provides a basis for further clinical diagnosis and preparation of new vaccines.

Experimental study on the inhibitory effect of soap solution on rabies viruses / 中华实验和临床病毒学杂志

Objective@#To investigate the inactivating effect of soap solution on rabies virus and to explore the concentration of soap solutions which could be effective in post-exposure prophylaxis (PEP) of rabies virus infection.@*Methods@#The BSR and N2a cells were respectively infected by the mixture of different concentrations of soap solution and rabies virus CVS-11. Based on the direct immunofluorescent method (DFA) and reverse transcription PCR (RT-PCR), the inactivating effects of soap solutions on rabies viruse in BSR and N2a cells were detected, respectively.@*Results@#This experiment established the BSR or N2a cells model in 24 well cell culture plates, and we found that the upper limit of soap solution concentration which BSR or N2a cells could tolerate was 1%. The inhibitory effect test of different soap solution on rabies virus showed that the 0.5% concentration of soap solution could completely inhibit the survival of CVS-11 strain in both the BSR and N2a cells, but the 0.1% concentration of soap solution could not inhibit the rabies viruses completely.@*Conclusions@#The 0.5%-1% concentration of soap solutions could inhibit the survival of CVS-11 strain in three minutes in vivo experiment.