安可信银离子免洗手消毒液的效果及安全性

目的评价一种以乙醇和银离子为主要成分的免洗手消毒液(安可信)的效果及其安全性。方法采用悬液定量杀菌试验、消毒剂对手消毒现场试验、急性经口毒性试验和小鼠骨髓嗜多染红细胞微核试验等方法,研究该免洗手消毒液杀菌效果以及安全性。结果银离子浓度为41.6 mg/kg、乙醇含量为54.4%(w/w)的该免洗手消毒液作用1 min,对大肠埃希菌、金黄色葡萄球菌和铜绿假单胞菌平均杀灭对数值>3.00;对白假丝酵母菌的平均杀灭对数值>4.00。该免洗手消毒液原液经37 ℃恒温培养箱保存3个月后,样品乙醇含量下降率为0.37%,银离子含量无下降。该免洗手消毒液对小鼠急性经口毒性LD₅₀>5 000 mg/kg,对新西兰家兔皮肤无刺激性,小鼠骨髓嗜多染红细胞微核试验结果为阴性。结论安可信银离子免洗手消毒液对细菌和真菌具有较好消毒作用;对人体无皮肤刺激;各项指标均符合国家要求。     

细菌对消毒剂抗性机理研究进展

消毒剂通过抑制膜的主动运输、抑制微生物的代谢、扰乱微生物的DNA复制、使微生物细胞裂解而导致胞内成分渗漏以及使胞内物质凝结等方面发挥灭菌作用.消毒剂在杀灭细菌和控制细菌污染方面具有重要作用,但细菌对消毒剂也会产生抗性.细菌对消毒剂的抗性机制主要通过形成生物被膜,阻挡或外排机制减少消毒剂分子进入细胞,使消毒剂分子失活,以及其他表型性耐药等4个途径来实现,其中通过形成生物被膜阻止消毒剂分子进入细菌细胞或在进入细胞前使消毒剂失去效用,在细菌对消毒剂的抗性机制中具有重要作用.以实际污染的主要菌株为对象,研究它们对常用消毒剂的抗性机制,对控制细菌污染具有极大的应用价值和现实意义.     

消毒剂对环境菌株抑制作用的研究

目的 研究企业常用消毒剂对于洁净室环境监测分离的菌株样本的抑制作用。方法 通过VITEK2-COMPACT全自动细菌鉴定及药敏分析系统鉴定收集到的环境菌株。对3种消毒剂(碘伏、无水乙醇和苯扎溴铵)进行梯度稀释,利用打孔法研究3种消毒剂在不同含量下对环境菌株的抑制作用。结果 共检出革兰阳性菌8种、革兰阴性菌2种、酵母菌1种、芽孢杆菌2种;苯扎溴铵对革兰阳性菌的抑菌能力都较强,随着含量的降低,抑菌作用逐渐减弱;碘伏对革兰阴性菌及酵母菌的抑制作用都非常强,随着含量降低,抑菌作用逐渐降低。3种消毒剂对2种芽孢杆菌的抑制作用均有限。结论 用1.00%苯扎溴铵和0.50%的碘伏抑菌作用都非常强。另外,应配合使用杀孢子剂,避免芽孢杆菌孢子在空气中传播。     

Antiprotozoal activity of magnesium oxide (MgO) nanoparticles against Cyclospora cayetanensis oocysts

Outbreaks of Cyclospora cayetanensis infection have been linked to consumption of food and water contaminated by oocysts that can survive both physical and chemical disinfectants. Magnesium oxide (MgO) nanoparticles (NPs) can be potentially used in food as bactericides. In this study, C. cayetanensis pre- and post-sporulated oocysts were exposed to MgO NPs with different doses ranging from 1.25–25?mg/ml. With comparison to control, the antiprotozoal activity of MgO NPs was evaluated by identifying the median effective concentration dose (EC₅₀), lethal concentration dose (LC₉₀), microscopically changes on treated oocysts and rates of sporulation. Among pre- and post-sporulated oocysts, MgO NPs?≥?EC₅₀ was observed after 24?h at concentrations 10 and 12.5?mg/ml, respectively, while?≥?LC₉₀ was observed after 24?h, 48?h and 72?h at concentrations 15, 12.5 and 10?mg/ml, respectively. MgO NPs treated oocysts showed abnormal morphological changes such as an increase in size, wall injury, deposition of vacuolated homogenous particles in the cytoplasm, evacuation of oocyst's contents, and collapse. Sporocysts of treated oocysts were noticed to be peripherally shifted. Sporulation failure of treated oocysts achieved ≥90% after 24?h and 72?h of incubation with 15 and 12.5?mg/ml, respectively, while it was 10.1% among non-treated. All the differences were statistically significant. Our results demonstrated that MgO NPs has a significant anti-Cyclospora effect on both unsporulated and sporulated oocysts, especially considering that it could be biologically synthesized, that way it can be used safely as a preventive agent in food and water disinfectant treatment.     

某新型冠状病毒肺炎定点医院病区终末消毒控制措施及效果监测

摘要 目的：了解新型冠状病毒（以下简称"新冠"）肺炎定点医院病区终末消毒控制措施并监测其消毒效果。方法：对中山大学附属第五医院隔离病区实施终末消毒，并对终末消毒前后空气和物表进行采样检测及终末消毒后环境进行采样检测，评估消毒效果。结果：对14个隔离病区开展了终末消毒，终末消毒前后均采集空气沉降菌样品156份、物表样品254份，终末消毒后采集环境核酸样品209份进行消毒效果评价。各隔离病区经终末消毒后空气消毒效果合格率均为100.00%，高于终末消毒前空气消毒效果合格率76.20%（P<0.05）；终末消毒后物表消毒效果为94.88%，高于终末消毒前物表消毒效果合格率71.65%（P<0.05）；终末消毒后环境核酸检测结果均为阴性。结论：中山大学附属第五医院各隔离病区经终末消毒后各项指标均符合终末消毒评价要求。     

多重耐药鲍曼不动杆菌消毒剂耐药基因检测及同源性分析

目的探讨多重耐药鲍曼不动杆菌（MDRAB）临床分离株对医院常用消毒剂苯扎溴铵和醋酸氯已定的耐药表型与qacE△1-sul1基因型的相关性并分析菌株的同源性。方法用微量肉汤稀释法检测菌株的最低抑菌浓度（MIC）和最低杀菌浓度（MBC）,用PCR方法检测qacE△1-sul1基因,用脉冲场凝胶电泳（PFGE）分析菌株的同源性。结果20株MDRAB中,18株（90％）qacE△l-sul1阳性,2株（10％）qacE△1-sul1阴性。qacE△1-sul1阳性株对苯扎溴铵的MIC50、MIC90、MBC50和MBC90分别是qacE△1-sul1阴性株的2倍、2倍、8倍和8倍。而qacE△1-sul1阳性株对醋酸氯已定的MIC50、MIC90、MBC50和MBC90分别是qacE△1-sul1阴性株的2倍、2倍、4倍和8倍。PF-GE显示：18株qacE△1-sul1阳性MDRAB可分为A～F6个PFGE克隆。2株qacE△1-sul1阴性MDRAB均为B克隆。结论MDRAB对消毒剂耐药性升高与qacE△1-sul1基因相关,临床存在多个克隆株的传播。     

抗消毒剂型微生物培养基研究

二氧化氯、过氧乙酸、次氯酸钠及过氧化氢等消毒剂高浓度可以杀灭微生物,低浓度可以抑制微生物生长。在微生物检测中,要消除消毒剂的干扰,培养基的抗消毒剂指数必须控制在１２．０—２４.５之间。消毒剂解抑剂Ⅰ的抗消毒剂指数为 １２．０,对细菌和真菌生长无明显抑制作用,加入经改良和优化的普通培养基后,制得５种抗消毒剂型培养基,在灭菌前后和一年的保存期内,其抗消毒剂指数基本保持不变。当采用大样倾注平板法和液体大样法检测残留消毒剂的样品时,使用抗消毒剂型培养基检出细菌和真菌能力大大高于普通培养基。     

Chemical analysis of materials used in pig housing with respect to the safety of products of animal origin

Bedding, environmental enrichment materials and disinfectant powders in pig farming are meant to ensure a hygienic bedding environment or allow pigs to perform explorative behaviour. To our knowledge, no legal regulation exists, that established maximum contents for undesirable substances, such as toxic metals, dioxins or trace elements in these materials, although oral ingestion could be expected. In the present study, a total of 74 materials (disinfectant powders [n = 51], earth/peat [n = 12], biochar [n = 8], recycled manure solids [n = 3]) were analysed for their content of various toxic metals, trace elements, dioxins and polychlorinated biphenyls. The data suggest that, in some samples, trace elements like iron, copper and zinc might have been added intentionally in order to induce physiological effects (iron supply to piglets, copper and zinc as growth promoter in pigs). Moreover, some materials contained high levels of lead, cadmium or arsenic. Consequently, if farm animals repeatedly consume environmental enrichment and bedding materials or disinfectant powders in considerable amounts and these quantities are added to the daily ration, the amount of ingested undesirable substances and trace elements might exceed the maximum levels set for complete feedstuffs, and an elevated transfer into food of animal origin might occur. Future studies are required to address the possible quantitative contribution in the light of feed and food safety. Finally, the excretion of undesirable substances with manure needs to be considered due to their possible accumulation in soils.     

Inactivation and mechanisms of chlorine dioxide on Nosema bombycis

Biological tests demonstrated that the inactivation of Nosema bombycis (N. bombycis) spores by chlorine dioxide (ClO₂) occurs very fast and is highly sensitive. The lowest effective inactivation dosage and time was 15 mg/mL for 30 min. The inactivation of spores was additionally verified by using double color fluorescence stain and spore germination testing. A series of biological changes, including a large number of substrates that were leaked out from the spores included proteins, DNA, polysaccharide, K⁺, and Ca²⁺, occurred a short time after N. bombycis spores were treated with ClO₂. In addition, the lipid of spores was disrupted and ATPase activity was inhibited, which resulted in the destruction of the inner structure of the spores.     

细菌的消毒剂耐药性

细菌的消毒剂耐药性指细菌与消毒剂多次接触后,使该类消毒剂的最小抑菌浓度或最小杀菌浓度升高的现象。细菌的消毒剂耐药性普遍存在,多种细菌可对一种消毒剂耐药,一种细菌可对多种消毒剂耐药。消毒剂选择件压力是耐药性产生的外在原因,产生的机制包括生化结构、遗传学途径和酶学途径。消毒剂耐药与抗生素耐药之间存在一定的关系。应加强研究,制定统一标准,加强监测,并制定合理应用消毒荆规范,以减少消毒剂耐药性的发生。