Relationship Between Antimicrobial Use and Antimicrobial Susceptibility in Pseudomonas aeruginosa Causing Nosocomial Infections

OBJECTIVE To evaluate the relationship between and antimicrobial usage antimicrobial susceptibility of Pseudomonas aeruginosa(PAE) causing nosocomial infections. METHODS Monitored the data on the yearly patient-days and the yearly consumption(defined daily dose(DDD) per 1000 patient days) the consumption of ceftazidime,cefepime,levofloxacin,piperacillin/tazobactam,cefoperazone/sulbactam,mipenem and meropenem from Jan 2003 to Dec 2007.was analyzed.Disk susceptibility data of P.aeruginosa(PAE) causing nosocomial infections were tested. RESULTS The yearly patient-days of our department significantly increased from 60 069 in 2003 to 74 442 in 2007(P 0.05).The usage of ceftazidime,cefoperazone/sulbactam and levofloxacin reduced 20 times,6 times and 2 times in 5 years,respectively(P 0.05).The consumption of piperacillin/tazobactam and cefepime increased 100 times and 30 times in 5 years,respectively(P 0.05).Increasing trends of ceftazidime-susceptible and cefoperazone/sulbactam-susceptible PAE(P 0.05)and decreasing trends of cefepime-susceptible PAE were noted from Jan 2003 to Dec 2007.The increments of susceptibility to CAZ and CFS were about 10%,and the decrement of susceptibility to FEP was 20% The rise in ceftazidime-susceptible and cefoperazone/ sulbactam-susceptible PAE was significantly correlated with decreased consumption of ceftazidime and cefoperazone/ sulbactam,and the fall in cefepime-susceptible PAE was significantly correlated with increased consumption of cefepime(r -0.72,P 0.05). CONCLUSIONS The consumption of CAZ,FEP,and CFS is significantly negatively correlated with their susceptibility of PAE causing nosocomial infections.