Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen ...Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen for cultured prussian carp(Carassius auratus gibelio)world-wide.In this study,a novel and effective method for concentration and quantification of live CyHV-2 virions from water was successfully established through coupling the iron flocculation with real time qPCR assay.Then,the shedding intensity of CyHV-2 in fish-tank water from artificially-challenged goldfish(25 fish/20 L)was monitored continuously for 7 days on a daily basis through quantitating viral genomic copy numbers by qPCR,and the maximum shedding level was determined to be 105 copies/L.Horizontal transmission research system was established by inoculating healthy goldfish in water spiked with serial dilution of CyHV-2 virions ranging from 107 to 103 copies/L.Our results indicated that water-borne CyHV-2 efficiently caused the infection of tested goldfish even in a concentration of 103 copies/L,and the overall transmission efficacy was not linearly correlated with the level of input virus in the fish tank.Commercial disinfectant Composite Sodium Chlorite Powder(CSCP)has been widely applied in aquaculture to control microbial infection through direct spill in the water,and its effect in inactivating the CyHV-2 infectivity remains unknown.We further determined that the EC50 of CSCP against 3.89 TCID50/mL CyHV-2 was close to 15.625μg/mL in vitro,and application of CSCP in a level as high as 60μg/mL(the safety concentration of CSCP for goldfish)couldn’t protect goldfish from CyHV-2 challenge through immersion.Thus,the disinfectant CSCP was regarded as none-effective for blocking CyHV-2 transmission in water during epidemic.Overall,our data provided quantitative data to demonstrate the shedding intensity of CyHV-2 in water,and CSCP was shown to be not effective in blocking water-borne horizontal transmission of CyHV-2 in goldfish.The virus-concentration protocol and virus-inhibition assay established here also paved the way for evaluating more commercial disinfectants in their effects in blocking water-borne horizontal transmission of CyHV-2.展开更多
Experiments of simultaneous removal of SO2 and NO from simulated flue gas,using NaClO2 solution as the absorbent,were carried out in a self-designed bubble reactor,and high simultaneous removal effi-ciencies of SO2 an...Experiments of simultaneous removal of SO2 and NO from simulated flue gas,using NaClO2 solution as the absorbent,were carried out in a self-designed bubble reactor,and high simultaneous removal effi-ciencies of SO2 and NO were obtained under the optimal experimental conditions.The mechanism of simultaneous removal based on NaClO2 acid solutions was proposed by analyzing the removal prod-ucts.Possibility and limitation of the desulfurization and denitrification using NaClO2 acid solutions were calculated by thermodynamic methods.Experimental results of reaction kinetics for simultaneous desulfurization and denitrification indicated that the oxidation-absorption processes of SO2 and NO were divided into two zones,namely the fast and slow reaction zones.In the slow reaction zones both were zero order reactions,and in the fast reaction zones,the reaction order,rate constant and activa-tion energy of SO2 reaction with absorbent were 1.4,1.22(mol.L-1)-0.4.s-1 and 66.25kJ.mol-1,respec-tively,and 2,3.15×103(mol.L-1)-1.s-1,and 42.50 kJ.mol-1 for NO reaction,respectively.展开更多
基金supported by the earmarked fund for China Agricultural Research System (CARS-45-16).
文摘Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen for cultured prussian carp(Carassius auratus gibelio)world-wide.In this study,a novel and effective method for concentration and quantification of live CyHV-2 virions from water was successfully established through coupling the iron flocculation with real time qPCR assay.Then,the shedding intensity of CyHV-2 in fish-tank water from artificially-challenged goldfish(25 fish/20 L)was monitored continuously for 7 days on a daily basis through quantitating viral genomic copy numbers by qPCR,and the maximum shedding level was determined to be 105 copies/L.Horizontal transmission research system was established by inoculating healthy goldfish in water spiked with serial dilution of CyHV-2 virions ranging from 107 to 103 copies/L.Our results indicated that water-borne CyHV-2 efficiently caused the infection of tested goldfish even in a concentration of 103 copies/L,and the overall transmission efficacy was not linearly correlated with the level of input virus in the fish tank.Commercial disinfectant Composite Sodium Chlorite Powder(CSCP)has been widely applied in aquaculture to control microbial infection through direct spill in the water,and its effect in inactivating the CyHV-2 infectivity remains unknown.We further determined that the EC50 of CSCP against 3.89 TCID50/mL CyHV-2 was close to 15.625μg/mL in vitro,and application of CSCP in a level as high as 60μg/mL(the safety concentration of CSCP for goldfish)couldn’t protect goldfish from CyHV-2 challenge through immersion.Thus,the disinfectant CSCP was regarded as none-effective for blocking CyHV-2 transmission in water during epidemic.Overall,our data provided quantitative data to demonstrate the shedding intensity of CyHV-2 in water,and CSCP was shown to be not effective in blocking water-borne horizontal transmission of CyHV-2 in goldfish.The virus-concentration protocol and virus-inhibition assay established here also paved the way for evaluating more commercial disinfectants in their effects in blocking water-borne horizontal transmission of CyHV-2.
基金Supported by the National High-Tech Research and Development Program of China("863" Project)(Grant No.2007AA061803)
文摘Experiments of simultaneous removal of SO2 and NO from simulated flue gas,using NaClO2 solution as the absorbent,were carried out in a self-designed bubble reactor,and high simultaneous removal effi-ciencies of SO2 and NO were obtained under the optimal experimental conditions.The mechanism of simultaneous removal based on NaClO2 acid solutions was proposed by analyzing the removal prod-ucts.Possibility and limitation of the desulfurization and denitrification using NaClO2 acid solutions were calculated by thermodynamic methods.Experimental results of reaction kinetics for simultaneous desulfurization and denitrification indicated that the oxidation-absorption processes of SO2 and NO were divided into two zones,namely the fast and slow reaction zones.In the slow reaction zones both were zero order reactions,and in the fast reaction zones,the reaction order,rate constant and activa-tion energy of SO2 reaction with absorbent were 1.4,1.22(mol.L-1)-0.4.s-1 and 66.25kJ.mol-1,respec-tively,and 2,3.15×103(mol.L-1)-1.s-1,and 42.50 kJ.mol-1 for NO reaction,respectively.
