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Role of the outer membrane permeability in the antibiotic resistance in Pseudomonas aerugionsa

外膜通透性在铜绿假单胞菌抗生素耐药性中的作用

基本信息

批准号：
02454179
负责人：
NAKAE Taiji
金额：
$ 3.14万
依托单位：
Tokai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

Pseudomonas aeruginosa is a pathogen to the immunocompromised host. Infection of this bacteria is a problem, since the bacteria is highly resistant to a number of structurally unrelated antibiotics. This high antibiotic resistance is due to low outer membrane permeability. To elucidate the role of the outer membrane permeability to the antibiotic resistance. we investigated the permeability properties of the porins. Purified outer membrane porins, proteins C, D2 and E1 were reconstituted into a planar membrane of diphytanoyl phosphatidyl choline in 1 M NaCl solution and the conductivity across the membrane was determined. The single channel conductance of protein C and El in I M NaCl appeared to be about 120 pS and 240 pS, respectively. The single channel conductance of protein D2 showed two discrete channel sizes of 10-30 pS and about 300-500 pS. The channel sizes are far smaller than that of E. coli porins (1200-1400 pS).Purified proteins C, D2 and El were reconstituted into the Iipo … More some membrane and the antibiotic permeability was determined. Among beta-lactam antibiotics, only carbapems, such as imipenem and meropenem showed efficient diffusion through the porin pores. Protein D2 showed higher efficiency in the imipenem permeability tha nother two porins. Other cephalosporins diffused through these porin pores little. Thus, role of protein D2 in the imipenem diffusion was clarified in vitro.Imipenem diffusion via protein D2 in vitro was tested by clonig P. aeruginosa gene coded for protein D2. The cloned gene was expressed in the protein D2-deficient host and over produced protein D2. The Protein D2-deficient host fully restored protein D2 upon harboring the protein D2-cloned plasmid.Thus, the role of protein D2 in the imipenem permeability was demonstrated in vitro.These studies clearly demonstrated that the outer membrane pores of Pseudomonas aeruginosa are far smaller than that of E. coli. Protein D2 is only the porin practically functioning in the carbapenem diffusion and the role of other porins in the antibiotic diffusion seems to be a little. Less

铜绿假单胞菌是免疫受损宿主的病原体。这种细菌的感染是一个问题，因为这种细菌对许多结构上不相关的抗生素具有高度耐药性。这种高抗生素抗性是由于低的外膜渗透性。阐明细菌外膜通透性在细菌耐药性中的作用。我们研究了孔蛋白的渗透性。将纯化的外膜孔蛋白、蛋白质C、D2和E1在1 M NaCl溶液中重构为二植烷酰磷脂酰胆碱的平面膜，并测定跨膜的电导率。蛋白质C和El在IM NaCl中的单通道电导似乎分别为约120 pS和240 pS。蛋白D2的单通道电导显示10-30 pS和约300-500 pS的两个离散通道大小。通道尺寸远小于E.将纯化的蛋白C、D2和E1重构到Iipo中， ...更多信息一些膜和抗生素渗透性测定。在β-内酰胺类抗生素中，只有碳青霉烯类，如亚胺培南和美罗培南显示出通过孔蛋白孔的有效扩散。蛋白D2对亚胺培南的渗透率高于其他两种孔蛋白。其他头孢菌素类药物很少通过这些孔蛋白孔扩散。通过克隆编码蛋白D2的铜绿假单胞菌基因，研究了蛋白D2在亚胺培南体外扩散中的作用。克隆的基因在蛋白D2缺陷的宿主中表达并过量产生蛋白D2。蛋白D2缺失的宿主在携带蛋白D2克隆质粒后完全恢复了蛋白D2，从而在体外证实了蛋白D2在亚胺培南渗透中的作用。杆菌蛋白D2是唯一在碳青霉烯扩散中实际起作用的孔蛋白，其他孔蛋白在抗生素扩散中的作用似乎很小。少