研究生细菌耐药与临床对策研2016ppt课件.pptVIP

Once resistant strains of bacteria are present in a population, exposure to antimicrobial drugs favors their survival Reducing antimicrobial selection pressure is one key to preventing antimicrobial resistance and preserving the utility of available drugs for as long as possible 形成救护机制，即形成新的代行途径代替原来被阻断的代谢途径来合成原来的代谢产物 β－内酰胺类抗生素的杀菌作用是抗生素与靶位一青霉素结合蛋白（Penicillin－Binding－proteins）结合；与PBP1结合，则影响细菌细胞壁生成，使细菌成为原生质球，进而溶菌死亡；与PBP2结合，细菌不能维持正常形态；与PBP3结合，可引起细菌分裂障碍，使细菌形成丝状，最终溶菌死亡。细菌在与抗生素的长期斗争中，只有极少数细菌存活下来。细菌迫于抗生素强大的筛选压力，使PBPs数量改变或与抗生素之间的亲和力减弱，以谋求生存，所以表现出程度不同的耐药性。 （即孔蛋白Porin）在耐药过程中起着重要作用，它对大多数水溶性抗菌药物具有良好的通透性。孔蛋白主要有OmPA、OmPF、OmpC，其中 OmpF与抗菌药物的通透性最相关 When considering the etiologic agent of a surgical site infection, the organisms encountered change according to the depth of the tissue involved. Superficial infections and cellulitis are usually caused by streptococci and staphylococci. As the infection spreads deeper, gram-negative rods and anaerobes become more common. [Nichols, p.S87] Thus, in choosing the appropriate prophylactic agent, it is important to know which organisms will be encountered. Reference Nichols RL, Florman S. Clinical presentations of soft-tissue infections and surgical site infections. Clin Infect Dis. 2001;33(suppl 2):S84-S93. Approved: 2004 EPCP Risk Factors for and Prevention of Surgical Site Infection Slide 20 Nichols, p.S87 手术部位感染(SSI) 在正常情况下，各种药物以一定的比率与血浆蛋白结合，在血浆中常同时存在结合型与游离型。而只有游离型药物才具有药物活性。 早期联合治疗，考虑感染时根据药敏早期联合，跟进CR病人更有效3天，腹腔和皮肤感染可以首先，其他感染碳氢霉烯三天调整方案有依据了 * 转换疗法是指不同抗菌药物由静脉给药改为口服给药，其药效不变。一般是同一级的不同抗菌药物之间的转换。 At present, a short-term antimicrobial treatment regimen is rarely prescribed, despite the potential major advantages it could have in terms of bacterial ecology and prevention of the emergence of multiresistant strains in the ICU. Chastre et al performed a randomized trial to compare the outcomes of therapy with an 8-day or 15-day antibiotic regimen for a well-defined group of ICU patients who had developed VAP, as confirmed by q