产NDM-1肠杆菌科细菌的研究进展

产新德里金属β-内酰胺酶-1(New delhimetallol-β-lactamase 1,NDM-1)肠杆菌科细菌对碳青霉烯类抗生素耐药,只对多黏菌素和替加环素敏感,接近于泛耐药菌株。此酶的blaNDM-1基因在肠杆菌科细菌间高效率的转移和人为因素(如旅游、卫生和食品的生产和制备)的影响,使其在全球迅速传播。目前有关其治疗的临床研究较少,为减缓NDM-1肠杆菌科细菌的传播,应加速开发诊断和治疗的相应措施。现就产NDM-1肠杆菌科细菌的分子生物学特点、诊断、治疗、新药研发和预防作一综述。     

细菌间bla_(NDM-1)传播规律的研究进展

新德里金属β-内酰胺酶-1 (New Delhi metallo-β-lactamase 1,NDM-1)导致革兰氏阴性细菌对几乎所有的β-内酰胺类抗生素(β-lactam antibiotic)产生抗性。携带NDM-1编码基因(bla_(NDM-1))的肠杆菌科(Enterobacteriaceae)和不动杆菌属(Acinetobacterspp.)细菌在世界各地广泛流行,严重威胁着公共健康。现对NDM-1的结构、突变亚型和传播规律进行综述,为预防和控制NDM-1携带菌提供策略。     

大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌超广谱β-内酰胺酶的检测及药敏分析

目的:了解本院大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌中超广谱β-内酰胺酶(ESBLs)细菌的发生率和药敏情况,为防止这3种细菌产ESBLs菌株的传播和抗生素的合理应用提供依据.方法:细菌鉴定用Vitek-32细菌鉴定仪,药敏试验用K-B法,ESBLs初筛用双纸片法,ESBLs确证用NCCLS1999年推荐的确证方法.结果:产ESBLs耐药菌占全部分离菌的33.2%,其中各细菌ESBLs发生率大肠埃希菌为28.6%,肺炎克雷伯菌为34.1%,阴沟肠杆菌为40.5%.对实验所做抗生素,ESBLs阳性株比阴性株具有更高的耐药率和更严重的交叉耐药现象.结论:本院大肠埃希菌、肺炎克雷伯菌和阴沟肠杆菌ESBLs发生率较高,较往年有上升趋势,ESBLs菌感染的治疗仍以亚胺培南为首选.     

肠杆菌科细菌产金属β-内酰胺酶的研究进展

金属β-内酰胺酶(MBL)可广泛水解多种抗生素,对常规β-内酰胺酶抑制剂如克拉维酸、舒巴坦等不敏感。产MBL肠杆菌科细菌一直是临床公认的多重耐药病原体。尤其是在发现新德里金属β-内酰胺酶后,人们更加重视肠杆菌科细菌中检出MBL的情况,因为其所致感染日渐严重。因此,快速、准确检测出产MBL菌株是有效预防、控制感染发生与播散的重要环节。本文就肠杆菌科细菌MBL的发现及分类、耐药基因传播、检测方法等进行简要概述。     

肠杆菌科细菌产金属β-内酰胺酶的研究进展

肠杆菌科细菌是社区获得性感染和院内感染的重要病原菌,近年来由于抗生素的大量、不合理使用,导致临床肠杆菌科细菌耐碳青霉烯类抗生素情况日趋严重,其中产金属β-内酰胺酶是导致细菌耐药的主要机制之一.本研究就对碳青霉烯类抗生素耐药的肠杆菌科细菌产生的金属β-内酰胺酶的研究进展作一综述.     

阴沟肠杆菌耐碳青霉烯类抗生素的耐药机制研究进展

阴沟肠杆菌是肠杆菌科中常见的院内感染细菌,碳青霉烯类抗生素由于其抗菌谱广、抗菌力强,成为治疗产ESBLs和AmpC酶革兰阴性杆菌感染的有效抗菌药物.但随着碳青霉烯类抗生素的广泛应用,临床上出现很多耐碳青霉烯类抗生素的阴沟肠杆菌(carbapenem-resistant Enterobacter cloacae,CREL),本研究就其耐药机制,从产碳青霉烯酶和非产碳青霉烯酶两方面做一综述.     

泛耐药细菌NDM-1基困Taqman PCR快速检测方法的建立

产NDM-1(New Delhi Metallo-β-lactamase 1,Ⅰ型新德里金属β-内酰胺酶)细菌是新近报道的一种泛耐药细菌,由于对绝大多数常用抗生素均耐药,又被称为超级细菌.目的:建立一种可快速检测泛耐药细菌NDM-1基因的Taqman探针实时荧光定量PCR法.方法:根据NDM-1基因序列,设计引物和Ta...     

革兰阴性杆菌ESBLs和AmpC酶的检测及耐药分析

目的检测引起医院感染的革兰阴性杆菌携带产ESBLs和去阻遏AmpC酶状况,探讨各菌对临床常用抗生素的主要耐药机制及耐药性,为临床制定合理使用抗生素策略提供依据。方法采用全自动微生物分析仪（VITEK-32）做细菌鉴定和药敏试验,用纸片扩散确证法检测超广谱β-内酰胺酶（ESBLs）,用三维法检测高水平表达染色体编码的AmpC酶。结果158株革兰阴性杆菌ESBLs检出率为26．6％,主要菌为大肠埃希菌（45．2％）、肺炎克雷伯菌（42．9％）、阴沟肠杆菌（11．9％）。AmpC酶检出率为10．1％,主要为鲍曼不动杆菌（43．8％）、阴沟肠杆菌（25％）;上述产酶细菌均对青霉素和一、二、三代头孢菌素、磺胺类、喹诺酮类、氨基糖苷类耐药,对亚胺培南敏感。结论革兰阴性杆菌耐药机制主要是产超广谱β-内酰胺酶和AmpC酶,这些产酶菌株均出现多重耐药。     

肠杆菌科细菌对β-内酰胺类抗生素耐药机制的研究现状

肠杆菌科细菌是革兰阴性杆菌中最常见的一类细菌,在一定条件下可引起医院和社区感染。临床首选β-内酰胺类抗生素来抗感染,但由于抗生素的不合理使用导致肠杆菌科细菌产生相应的灭活酶及水解酶或菌株细胞结构改变,从而破坏β-内酰胺环使其对抗生素作用的敏感性下降甚至耐药,给临床抗感染治疗带来了极大的挑战;为更好地指导临床用药,拟就肠杆菌科细菌的耐药表型、对β-内酰胺类抗生素的耐药机制做一综述。     

肺炎克雷伯菌碳青霉烯酶检测方法的研究进展

碳青霉烯类抗生素是治疗产超广谱β-内酰胺酶以及高产头孢菌素酶肠杆菌科细菌感染最有效的药物.但近年来,出现越来越多对其耐药的细菌,其中肺炎克雷伯菌碳青霉烯酶(Klebsilla pneumoniae carbapenemase,KPC)是引起肠杆菌科细菌对碳青霉烯类耐药的主要机制,目前产KPC细菌呈世界范围流行趋势,且其感染死亡率高,故需快速、灵敏的检测方法,以提高感染患者治愈率.     

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