老年肺部感染和抗菌药.ppt

* * * * * * * * * * * * Reference: Richards MJ, Edwards JR, Culver DH, Gaynes RP. Nosocomial infections in medical intensive care units in the United States. Crit Care Med. 1999;27:887-892. Richards/6/C Richards/7/A * * * * Introduction of every new class of antimicrobial drug is followed by emergence of resistance. By the 1950s, penicillin-resistant S. aureus were a major threat in hospitals and nurseries. By the 1970s, methicillin-resistant S. aureus had emerged and spread, a phenomenon that encouraged widespread use of vancomycin. In the 1990s, vancomycin-resistant enterococci emerged and rapidly spread; most of these organisms are resistant to other traditional first-line antimicrobial drugs. At the end of the century, the first S. aureus strains with reduced susceptibility to vancomycin were documented, prompting concerns that S. aureus fully resistant to vancomycin may be on the horizon. In June 2002 the first case of vancomycin-resistant S. aureus was detected. * The proportion of pathogens causing hospital-onset infections that are resistant to target antimicrobial drugs continues to increase at an alarming rate. Currently, more that 50% of Staphylococcus aureus isolates causing infections in intensive care units are resistant to methicillin; more than 40% are resistant in other hospital units. Vancomycin-resistant enterococci (VRE) emerged in the late 1980s and are now endemic in many hospitals. In many hospitals, more than 25% of enterococcal infections are caused by vancomycin-resistant strains. * The problem of antimicrobial resistance also includes gram-negative organisms. Klebsiella and many other Enterobacteriaceae have acquired extended-spectrum beta-lactamases (ESBL) that confer resistance to cephalosporins. Resistance to fluoroquinolones is also emerging, an observation attributable to the expanding use of this class of antimicrobials in the past decade. * * * * * * * * * * * * * * * * * * * * * * * * * 不良反应 神经系统损害 氨基糖苷类： 1 耳毒性：前庭功能