Nano-MgO with various particle sizes, synthe- sized by different methods using Mg(NO3)2·6H2O, Na2CO3, Na2SO4, urea and ammonia solution as reactants, was used to carry out bactericidal experiments on Bacillus sub...Nano-MgO with various particle sizes, synthe- sized by different methods using Mg(NO3)2·6H2O, Na2CO3, Na2SO4, urea and ammonia solution as reactants, was used to carry out bactericidal experiments on Bacillus subtilis var. niger. The results were compared with the effect of TiO2, a common kind of photocatalytic material. The materials were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), low temperature N2 adsorp- tion-desorption measurements and FT-IR, and the results showed that the bactericidal ability of MgO increases with decreasing particle size. Nano-MgO and an interior wall-paint containing the material have better bactericidal effects than nono-TiO2 in both presence and absence of light. The bactericidal mechanism is discussed. The surface of MgO can generate high concentrations of O?2 which is highly active and can react with the peptide linkages in the coating walls of the spores. The spores are destroyed by the resulting damage to their structure.展开更多
Objective:Chlorine dioxide(CD) gas has been used as a fumigant in the disinfection of biosafety labo-ratories.In this study,some experiments were conducted to assess the inactivation of spores inoculated on six ma-ter...Objective:Chlorine dioxide(CD) gas has been used as a fumigant in the disinfection of biosafety labo-ratories.In this study,some experiments were conducted to assess the inactivation of spores inoculated on six ma-terials [stainless steel(SS),painted steel(PS),polyvinyl chlorid(PVC),polyurethane(PU),glass(GS),and cotton cloth(CC)] by CD gas.The main aims of the study were to determine the sporicidal efficacy of CD gas and the effect of prehumidification before decontamination on sporicidal efficacy.Methods:Material coupons(1.2 cm diameter of SS,PS,and PU;1.0 cm×1.0 cm for PVC,GS,and CC) were contaminated with 10 μl of Bacillus subtilis var.niger(ATCC 9372) spore suspension in mixed organic burden and then dried in a biosafety cabinet for 12 h.The spores were recovered by soaking the coupons in 5 ml of extraction liquid for 1 h and then vortexing the liquid for 1 min.Results:The log reductions in spore numbers on inoculated test materials exposed to CD gas [0.080%(volume ratio,v/v) for 3 h] were in the range of from 1.80 to 6.64.Statistically significant differences were found in decontamination efficacies on test material coupons of SS,PS,PU,and CC between with and without a 1-h prehumidification treatment.With the extraction method,there were no statistically significant differences in the recovery ratios between the porous and non-porous materials.Conclusions:The results reported from this study could provide information for developing decontamination technology based on CD gas for targeting surface microbial contamination.展开更多
To examine the sterilizing effect and mechanism of neutron radiation, Bacillus subtills var. niger, strain （ATCC 9372） spores were irradiated with the fast neutron from the Chinese fast burst reactor II（CFBR-II）. ...To examine the sterilizing effect and mechanism of neutron radiation, Bacillus subtills var. niger, strain （ATCC 9372） spores were irradiated with the fast neutron from the Chinese fast burst reactor II（CFBR-II）. The plate-count results indicated that the D10 value was 384.6 Gy with a neutron radiation dose rate of 7.4 Gy/min. The rudimental catalase activity of the spores declined obviously with the increase in the radiation dose. Meanwhile, under the scanning electron microscope, no visible influence of the neutron radiation on the spore configuration was detected even if the dose was increased to 4 kGy. The content and distribution of DNA double-strand breaks induced by neutron radiation at different doses were measured and quantified by pulsed- field gel electrophoresis （PFGE）. Further analysis of the DNA release percentage （PR）, the DNA breakage level （L）, and the average molecular weight, indicated that DNA fragments were obvi- ously distributed around the 5 kb regions at different radiation doses, which suggests that some points in the DNA molecule were sensitive to neutron radiation. Both PR and L varied regularly to some extent with the increase in radiation dose. Thus neutron radiation has a high sterilization power, and can induce falling enzyme activity and DNA breakage in Bacillus subtilis spores展开更多
为了解专门电解生成机生成的酸性氧化电位水消毒性能,采用流动载体浸泡杀菌试验和动物试验方法对其杀菌效果及毒性进行了试验观察。结果,联邦牌酸化水生成机产生的酸性氧化电位水原液对白色念珠菌作用4m in,对枯草杆菌黑色变种芽孢作用1...为了解专门电解生成机生成的酸性氧化电位水消毒性能,采用流动载体浸泡杀菌试验和动物试验方法对其杀菌效果及毒性进行了试验观察。结果,联邦牌酸化水生成机产生的酸性氧化电位水原液对白色念珠菌作用4m in,对枯草杆菌黑色变种芽孢作用10 m in,平均杀灭对数值≥3.00;体积分数50%该酸化水对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌作用2 m in,平均杀灭对数值均≥3.00。该酸性氧化电位水对小鼠急性口服毒性试验属实际无毒;对家兔皮肤、黏膜无刺激性;对小鼠嗜多染红细胞无致微核作用。酸性氧化电位水原液浸泡72 h,对碳钢有中度腐蚀,对铝有轻度腐蚀,对不锈钢和铜基本无腐蚀。结论,该酸性氧化电位水具有很好的杀菌能力,属无毒类物质,对皮肤黏膜无刺激性,对金属具有一定腐蚀性。展开更多
利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384....利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384.6Gy,中子剂量与存活芽孢对数满足y=-0.0026x+10.462的函数关系;在剂量为800Gy时,剂量率与存活芽孢对数满足y=7.7414X-0.0834的函数关系;升高温度有利于中子辐射灭菌;中子辐照不同状态芽孢,其存活率为:菌片>粉末>液体。展开更多
一元制剂二氧化氯消毒粉剂是由3种主要成分组成,为了解其杀菌效果和毒性,采用悬液定量杀菌试验和动物毒性试验进行了实验室研究。结果,以含30 mg/L二氧化氯该消毒剂水溶液对悬液内大肠杆菌作用5 m in,平均杀灭率为99.95%;15 mg/L二氧化...一元制剂二氧化氯消毒粉剂是由3种主要成分组成,为了解其杀菌效果和毒性,采用悬液定量杀菌试验和动物毒性试验进行了实验室研究。结果,以含30 mg/L二氧化氯该消毒剂水溶液对悬液内大肠杆菌作用5 m in,平均杀灭率为99.95%;15 mg/L二氧化氯消毒液对金黄色葡萄球菌作用5 m in,平均杀灭率为99.91%;60 mg/L二氧化氯消毒液对枯草杆菌黑色变种芽孢作用10 m in,平均杀灭率为99.94%。以200 mg/L二氧化氯消毒液作用5m in,可完全破坏悬液内HBsAg的抗原性。菌悬液内含体积分数25%以上小牛血清对其杀灭大肠杆菌效果有轻度影响。该二氧化氯消毒粉剂对小鼠急性经口LD50值大于5000 mg/kg,属无毒类物质;以100 mg/L二氧化氯消毒液对家兔皮肤刺激试验指数为0.63,属于轻度刺激性。结论,一元制剂二氧化氯消毒粉剂对细菌繁殖体和细菌芽孢具有良好的杀菌效果,动物毒性试验属无毒类物质、对家兔皮肤有轻度刺激性。展开更多
目的改进完善Ⅱ级生物安全柜生物测试的方法,观察两种指示微生物的空气生物学特性。方法采用改良美国NF-49标准方法,以粘质沙雷菌为指标菌检测生物安全柜防护性能。结果枯草杆菌黑色变种芽孢经过porton采样器冲击30 m in,其相对存活率只...目的改进完善Ⅱ级生物安全柜生物测试的方法,观察两种指示微生物的空气生物学特性。方法采用改良美国NF-49标准方法,以粘质沙雷菌为指标菌检测生物安全柜防护性能。结果枯草杆菌黑色变种芽孢经过porton采样器冲击30 m in,其相对存活率只有37%;而粘质沙雷菌经30 m in冲击,其相对存活率为88%。枯草杆菌黑色变种芽孢经30 m in雾化,其相对存活率为53%;粘质沙雷菌雾化30 m in,其相对存活率为89%。实验环境中粘质沙雷菌本底检测结果菌落数均为0,粘质沙雷菌在自然界空气中不是优势菌株,不会对检测产生干扰。两台生物安全柜在不同风速下防护性能检测结果全部合格且与该安全柜出厂检测结果一致。结论粘质沙雷菌具有良好的雾化和冲击耐受性,受检的安全柜的人员、样品和环境防护作用合格,本研究建立的检测验证方法灵敏性和重复性与美国标准(NF-49)一致。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.90306012).
文摘Nano-MgO with various particle sizes, synthe- sized by different methods using Mg(NO3)2·6H2O, Na2CO3, Na2SO4, urea and ammonia solution as reactants, was used to carry out bactericidal experiments on Bacillus subtilis var. niger. The results were compared with the effect of TiO2, a common kind of photocatalytic material. The materials were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), low temperature N2 adsorp- tion-desorption measurements and FT-IR, and the results showed that the bactericidal ability of MgO increases with decreasing particle size. Nano-MgO and an interior wall-paint containing the material have better bactericidal effects than nono-TiO2 in both presence and absence of light. The bactericidal mechanism is discussed. The surface of MgO can generate high concentrations of O?2 which is highly active and can react with the peptide linkages in the coating walls of the spores. The spores are destroyed by the resulting damage to their structure.
基金Project supported by the National Key Science and Technology Specific Project for Prevention and Treatment of Major Infectious Diseases in China (No. 2009ZX10004-709)the National Key Technology R&D Program in the 11th Five-Year Plan of China (No.2008BAI62B01)
文摘Objective:Chlorine dioxide(CD) gas has been used as a fumigant in the disinfection of biosafety labo-ratories.In this study,some experiments were conducted to assess the inactivation of spores inoculated on six ma-terials [stainless steel(SS),painted steel(PS),polyvinyl chlorid(PVC),polyurethane(PU),glass(GS),and cotton cloth(CC)] by CD gas.The main aims of the study were to determine the sporicidal efficacy of CD gas and the effect of prehumidification before decontamination on sporicidal efficacy.Methods:Material coupons(1.2 cm diameter of SS,PS,and PU;1.0 cm×1.0 cm for PVC,GS,and CC) were contaminated with 10 μl of Bacillus subtilis var.niger(ATCC 9372) spore suspension in mixed organic burden and then dried in a biosafety cabinet for 12 h.The spores were recovered by soaking the coupons in 5 ml of extraction liquid for 1 h and then vortexing the liquid for 1 min.Results:The log reductions in spore numbers on inoculated test materials exposed to CD gas [0.080%(volume ratio,v/v) for 3 h] were in the range of from 1.80 to 6.64.Statistically significant differences were found in decontamination efficacies on test material coupons of SS,PS,PU,and CC between with and without a 1-h prehumidification treatment.With the extraction method,there were no statistically significant differences in the recovery ratios between the porous and non-porous materials.Conclusions:The results reported from this study could provide information for developing decontamination technology based on CD gas for targeting surface microbial contamination.
基金supported by Defense Key Laboratory of Nuclear Wastes and Environmental Safety Scientific Research Fund of the Southwest University of Science and Technology of China (No.07JGZB07)the China Academy of Engineering Physics Developing Fund
文摘To examine the sterilizing effect and mechanism of neutron radiation, Bacillus subtills var. niger, strain （ATCC 9372） spores were irradiated with the fast neutron from the Chinese fast burst reactor II（CFBR-II）. The plate-count results indicated that the D10 value was 384.6 Gy with a neutron radiation dose rate of 7.4 Gy/min. The rudimental catalase activity of the spores declined obviously with the increase in the radiation dose. Meanwhile, under the scanning electron microscope, no visible influence of the neutron radiation on the spore configuration was detected even if the dose was increased to 4 kGy. The content and distribution of DNA double-strand breaks induced by neutron radiation at different doses were measured and quantified by pulsed- field gel electrophoresis （PFGE）. Further analysis of the DNA release percentage （PR）, the DNA breakage level （L）, and the average molecular weight, indicated that DNA fragments were obvi- ously distributed around the 5 kb regions at different radiation doses, which suggests that some points in the DNA molecule were sensitive to neutron radiation. Both PR and L varied regularly to some extent with the increase in radiation dose. Thus neutron radiation has a high sterilization power, and can induce falling enzyme activity and DNA breakage in Bacillus subtilis spores
文摘为了解专门电解生成机生成的酸性氧化电位水消毒性能,采用流动载体浸泡杀菌试验和动物试验方法对其杀菌效果及毒性进行了试验观察。结果,联邦牌酸化水生成机产生的酸性氧化电位水原液对白色念珠菌作用4m in,对枯草杆菌黑色变种芽孢作用10 m in,平均杀灭对数值≥3.00;体积分数50%该酸化水对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌作用2 m in,平均杀灭对数值均≥3.00。该酸性氧化电位水对小鼠急性口服毒性试验属实际无毒;对家兔皮肤、黏膜无刺激性;对小鼠嗜多染红细胞无致微核作用。酸性氧化电位水原液浸泡72 h,对碳钢有中度腐蚀,对铝有轻度腐蚀,对不锈钢和铜基本无腐蚀。结论,该酸性氧化电位水具有很好的杀菌能力,属无毒类物质,对皮肤黏膜无刺激性,对金属具有一定腐蚀性。
文摘利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384.6Gy,中子剂量与存活芽孢对数满足y=-0.0026x+10.462的函数关系;在剂量为800Gy时,剂量率与存活芽孢对数满足y=7.7414X-0.0834的函数关系;升高温度有利于中子辐射灭菌;中子辐照不同状态芽孢,其存活率为:菌片>粉末>液体。
文摘一元制剂二氧化氯消毒粉剂是由3种主要成分组成,为了解其杀菌效果和毒性,采用悬液定量杀菌试验和动物毒性试验进行了实验室研究。结果,以含30 mg/L二氧化氯该消毒剂水溶液对悬液内大肠杆菌作用5 m in,平均杀灭率为99.95%;15 mg/L二氧化氯消毒液对金黄色葡萄球菌作用5 m in,平均杀灭率为99.91%;60 mg/L二氧化氯消毒液对枯草杆菌黑色变种芽孢作用10 m in,平均杀灭率为99.94%。以200 mg/L二氧化氯消毒液作用5m in,可完全破坏悬液内HBsAg的抗原性。菌悬液内含体积分数25%以上小牛血清对其杀灭大肠杆菌效果有轻度影响。该二氧化氯消毒粉剂对小鼠急性经口LD50值大于5000 mg/kg,属无毒类物质;以100 mg/L二氧化氯消毒液对家兔皮肤刺激试验指数为0.63,属于轻度刺激性。结论,一元制剂二氧化氯消毒粉剂对细菌繁殖体和细菌芽孢具有良好的杀菌效果,动物毒性试验属无毒类物质、对家兔皮肤有轻度刺激性。
文摘目的改进完善Ⅱ级生物安全柜生物测试的方法,观察两种指示微生物的空气生物学特性。方法采用改良美国NF-49标准方法,以粘质沙雷菌为指标菌检测生物安全柜防护性能。结果枯草杆菌黑色变种芽孢经过porton采样器冲击30 m in,其相对存活率只有37%;而粘质沙雷菌经30 m in冲击,其相对存活率为88%。枯草杆菌黑色变种芽孢经30 m in雾化,其相对存活率为53%;粘质沙雷菌雾化30 m in,其相对存活率为89%。实验环境中粘质沙雷菌本底检测结果菌落数均为0,粘质沙雷菌在自然界空气中不是优势菌株,不会对检测产生干扰。两台生物安全柜在不同风速下防护性能检测结果全部合格且与该安全柜出厂检测结果一致。结论粘质沙雷菌具有良好的雾化和冲击耐受性,受检的安全柜的人员、样品和环境防护作用合格,本研究建立的检测验证方法灵敏性和重复性与美国标准(NF-49)一致。
