6Fadda G,Spanu T, Ardito F, et al.Antimicrobial resistance among non-fermentative gram-negative bacilli isolated from the respiratory tracts of Italian inpatients:a 3- year surveillance study by the Italian epidemiological survey[J].Int J Antimicropb Agents,2004,23(3):254.
7Richard P W. Prevention and control of nosocomial infection[J]. Hosp Infect,1988,9(8):323.