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Background with the broad-spectrum antimicrobial drugs widely used in clinical , bacterial resistance has become a major problem in the infected areas , especially in recent years, bacterial resistance to the growing and complex , not only seriously affect hinder the control of infectious diseases and treatment , but also greatly increased medical expenses . Thus, taking advantage of the distribution of clinical bacterial infection and susceptibility important guiding role in the rational use of antibiotics to control infectious diseases . Pseudomonas aeruginosa is the main pathogens of nosocomial infections , complex resistance mechanisms of acquired resistance , both natural resistance characteristics of a variety of drugs , but also easy to use of antimicrobial drugs , β- lactamase generation of P. aeruginosa resistance to beta - lactam antibiotics main reason , as the third generation cephalosporins in clinical increasingly wide range of applications , bacterial β- lactamase resistance gene mutation , a new beta - lactamase , it can hydrolyze the β - lactam antibiotics , can also hydrolyze extended spectrum cephalosporin , so called extended-spectrum β- lactamase ( of ESBLs ) . Plasmid-mediated and chromosome -mediated two ESBLs , plasmid-mediated ESBLs can to produce a mutated gene transfer to homologous or heterologous strains , the more bacteria become resistant to many of ESBLs producing strains in vitro Orders susceptibility testing showed sensitivity to cephalosporins and single lactam antibiotics in clinical resistance to cause great harm to the clinical treatment . As ESBLs by the plasmid carrying easily passed between bacteria proliferation, resulting in the widespread dissemination of resistant bacteria , therefore, early and accurate detection of ESBLs crucial . Edition promulgated NCCLS1999 the ESBLs phenotypic screening and confirmation test is the most widely used method of detection of ESBLs The principle is based on the phenotypic characteristics of ESBLs can be inhibited by the β-lactam inhibitors : However ESBLs producing clinical isolates often accompanied it other complex mechanisms of resistance , thus limiting the application of this method in clinical testing . Other detection methods , such as the E-test method , three-dimensional test , Vitek machine identification
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