耐甲氧西林金黄色葡萄球菌系统性感染小鼠模型的制备

目的采用临床分离的耐甲氧西林金黄色葡萄球菌(MRSA)感染ICR小鼠,建立MRSA系统性感染小鼠模型。方法采用连续3 d腹腔注射环磷酰胺(100 mg/kg)进行免疫抑制后,将浓度为1×107cfu/m L的MRSA菌液经尾静脉接种ICR小鼠,通过生存分析、外周血白细胞计数、组织载菌量和病理学检查对模型进行评价。结果 MRSA接种后第2天小鼠开始死亡,14 d内累积死亡率达60%;外周血白细胞总数显著升高,细菌在多个器官定植,载菌量由高到低依次是肾、关节、肺、肝和脑,肾载菌量高达109CFU/g,关节、肺、肝和脑的载菌量范围在104~109CFU/g。病理观察显示肾、心脏、肺、肝、脑和关节多器官感染的组织病理学改变。结论采用环磷酰胺免疫抑制后静脉接种MRSA的方法首次成功建立MRSA系统性感染小鼠模型,该模型可应用于MRSA发病机理及药物筛选等研究领域。     

国外信息(二)

1.社区获得性耐甲氧西林金黄色葡萄球菌流行又有新证据(Clin Infect Dis,2008,46:787～794) 近期研究提示,社区获得性耐甲氧西林金黄色葡萄球菌(MRSA)感染正越来越多发生在护理机构中.美国芝加哥Rush大学医学中心Popovich等采用表型及基因型分析的方法描述了医院内感染的社区获得性MRSA血流感染的流行病学.     

葡萄球菌下呼吸道感染的细菌学分类及抗生素敏感性分析

目的：探讨葡萄球菌下呼吸道感染的细菌学分类情况及抗生素耐药性特点。方法：利用复星公司FOUTUNE IMS细菌鉴定药敏分析系统,凝固酶试验用试管法。结果：47株菌株分离到6种葡萄球菌,排在前3位的是施氏葡萄球菌、金黄色葡萄球菌、木糖葡萄球菌,其中金黄色葡萄球菌占29．8％。耐甲氧西林葡萄球菌（MRS）占78．7％,耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）占凝固酶阴性葡萄球菌（CNS）78．8％;MRS对万古霉素敏感率为81．1％。MRS建议用药依次为万古霉素、呋喃妥因、氯霉素、四环素和喹诺酮类,未发现对万古霉素耐药的耐甲氧西林金黄色葡萄球菌（MRSA）。结论：凝固酶阴性、耐甲氧西林葡萄球菌成为下呼吸道球菌感染的主要菌株,MRS比例上升,MRS治疗首选万古霉素。     

耐药细菌分析——“只有民族的才是世界的”

正细菌的耐药问题已经成为一种全球性的严重威胁[1],耐甲氧西林金黄色葡萄球菌(MRSA)、多重耐药鲍曼不动杆菌和耐药性艰难梭菌等多种耐药细菌感染疾病负担巨大,中国的情况尤其严重。近期中国研究团队在动物和人源细菌中均发现了一种新型的位于细菌质粒上的粘菌素耐药基因mcr-1[2],使细菌耐药问题受到进一步关注。本刊2015年第1期刊登了杨永刚、陈瑜等的研究文章"耐甲氧西林金黄色葡萄球菌分型及流行现状"[3],     

耐甲氧西林金黄色葡萄球菌及其肠毒素的检测和耐药性分析

目的评价乳胶结合试验检测耐甲氧西林金黄色葡萄球菌(MRSA)及其肠毒素(SE),并进行耐药性分析.方法收集130株金黄色葡萄球菌临床分离株,通过药敏试验将其分为耐甲氧西林金黄色葡萄球菌和甲氧西林敏感金黄色葡萄球菌(MSSA),用反向间接血凝试验(RPHA)检测金黄色葡萄球菌肠毒素.结果67株MR-SA产肠毒素,19株MSSA产肠毒素,MRSA产肠毒素率为100%,MSSA产肠毒素率为30%.结论实验室应重视金黄色葡萄球菌肠毒素的检测.     

《野生动物疾病》：野生动物中发现耐药超级细菌

根据《野生动物疾病》杂志的一项最新研究,人类当中最臭名昭著和最难以治疗的细菌之一发现于野生动物当中。研究人员从两只兔子和一只沙鸥中分离出了耐甲氧西林金黄色葡萄球菌（MRSA）。     

葡萄球菌耐药性的监测分析

目的：研究葡萄球菌的感染及耐药性状况,指导临床合理用药。方法：常规方法及阳光微生物鉴定仪鉴定菌株。药敏试验用革兰阳性需氧球菌药敏检测卡,检测耐甲氧西林金黄色葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）,金黄色葡萄球菌（SA）和凝固酶阴性葡萄球菌（CNS）对12种抗生素的耐药率。结果：158株葡萄球菌中,MRSA占47.5%（78/158）,MRCNS占21.5%(34/158),SA占70.9%（112/158）,CNS占29.1%(46/158)。耐甲氧西林葡萄球菌（MRS）对12种抗生素的耐药率均高于甲氧西林敏感葡萄球菌（MSSA）。结论：MRSA的耐药性较高,需加强其抗生素的耐药性检测。     

氯氰碘柳胺与环丙沙星对耐甲氧西林金黄色葡萄球菌的体外联合药敏试验分析

目的 评价氯氰碘柳胺与环丙沙星联用对60株环丙沙星均为耐药的耐甲氧西林金黄色葡萄球菌(MRSA)的体外抗菌效应.方法 采用棋盘法设计,微量肉汤稀释法测定不同浓度组合的抗菌药物对60株甲氧西林耐药的金黄色葡萄球菌(MRSA)的最低抑菌浓度,并计算部分抑菌浓度指数(FICI)判定联合效应.结果 氯氰碘柳胺与环丙沙星联合用药后,其FICI分布:FIC≤0.5为20.0％,0.5 ＜FIC≤1为66.7％,1＜FIC≤2为13.3％,FIC＞2为0.结论 体外氯氰碘柳胺与环丙沙星联用对60株耐甲氧西林金黄色葡萄球菌的作用主要为相加和协同作用.     

mecA、femA基因与MRSA及MRCNS的相关性研究

耐甲氧西林金黄色葡萄球菌(MRSA)及耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)是引起医院和社区人群感染的主要病原菌。由于其异质性和多重耐药,使临床治疗非常棘手。对m ecA与femA基因及耐药性的相关研究,在临床用药和防止播散意义重大。     

金黄色葡萄球菌对碘伏、乙醇、高铁酸钾和紫外线的抗性

目的了解临床分离的耐甲氧西林金黄色葡萄球菌（methicillin resistant Staphylococcus aureus,MR-SA）、甲氧西林敏感的金黄色葡萄球菌（methicillin sensitive Staphylococcus aureus,MSSA）及金黄色葡萄球菌CMCC（B）26003对碘伏、乙醇医院常用消毒剂及紫外线的抗性。方法以临床连续收集的67株金黄色葡萄球菌为实验菌株。测定碘伏、乙醇、高铁酸钾对耐甲氧西林金黄色葡萄球菌（MRSA）、甲氧西林敏感的金黄色葡萄球菌（MSSA）和金黄色葡萄球菌CMCC（B）26003作用1、2min后的最小抑菌浓度（MBC）及紫外线作用不同时间后的杀菌试验,观察其对碘伏、乙醇、高铁酸钾及紫外线抗性的变化趋势。结果碘伏对MRSA的MBC明显高于MSSA及CMCC（B）26003,而乙醇、高铁酸钾对3种菌的最小抑菌浓度均相近,3种菌对紫外线抗性相近。结论在正常使用浓度范围内碘伏、乙醇、高铁酸钾对金黄色葡萄菌中无论是MRSA、MSSA都有很好的灭菌作用,且乙醇作用时间越长,抑菌效果越显著。紫外线在作用75min以上时,3种菌全部不能存活。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism