The Implementation of a Hospital-wide Practice for the Selective Use of Carbapenems Based on the Monitoring of Susceptibility of Pseudomonas aeruginosa Isolates.

OBJECTIVES: To control carbapenem-resistant Pseudomonas aeruginosa, we implemented a hospital-wide policy concerning the selective use of carbapenems based on the monitoring of P. aeruginosa isolates for susceptibility to five carbapenems using a customized dry plate method. In this study, we retrospectively investigated the outcome of our measures to control carbapenem-resistant P. aeruginosa. METHODS: To select effective carbapenems, 100 clinical isolates were collected, and the minimum inhibitory concentration (MIC) to 5 carbapenems (IPM/CS, MEPM, DRPM, BIPM and PAPM/BP) was monitored using a customized dry plate method from 2006 to 2013. Carbapenems, which were associated with a high rate of drug resistance in P. aeruginosa, were restricted from use during our intervention study. The antimicrobial use density per 100 bed-days (AUD100) of carbapenems and the detection rates of carbapenem (IPM/CS and MEPM)-resistant P. aeruginosa were determined during the period of the intervention. RESULTS: The isolates consistently showed higher rates of drug-resistant P. aeruginosa in IPM/CS and PAPM/BP. Thus, DRPM, MEPM and BIPM were adopted for hospital-wide use. The detection rates of all IPM/Cs and MEPM-resistant P. aeruginosa significantly decreased. Meanwhile, the consumption of carbapenems showed an increasing trend. CONCLUSIONS: The outcome of the hospital-wide implementation of the selective use of carbapenems based on periodic monitoring of the susceptibility of P. aeruginosa isolates was retrospectively studied. Implementation of this measure might have contributed in part to the control of carbapenem-resistant P. aeruginosa in our hospital.

Performance Evaluation of a Newly Developed and Fully Automated Bacteriological Analyzer "RAISUS ANY" for Antimicrobial Susceptibility Testing of Fastidious Bacteria Haemophilus influenzae and Streptococcus pneumoniae.

OBJECTIVE: Antimicrobial susceptibility testing for fastidious bacteria, such as Haemophilus influenzae (H. influenzae) and Streptococcus pneumoniae (S. pneumoniae) has been performed manually. We evaluated the performance of a newly developed fully automated system for rapid bacterial identification and antimicrobial susceptibility testing "RAISUS ANY" (Nissui Pharmaceutical Co., Ltd.). METHODS: We evaluated the performance of "RAISUS ANY" for measurement of minimal inhibitory concentrations (MICs) of H. influenzae and S. pneumoniae, in comparison with the manual method (DP34, Eiken Chem. Co., Ltd.). The repeatability of MICs was studied using the reference strain of these bacteria, obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA). RESULTS: The comparison with the manual method for 35 and 36 clinical strains of H. influenzae and S. pneumonia showed 62.9-100% and 86.1-100% agreement, respectively. Five of 35 H. influenzae strains that showed a trailing effect were stably and accurately measured for MICs without a variation among the examiners. CONCLUSION: In conclusion, the automated system "RAISUS ANY" provided a reliable MICs data for H. influenzae and S. pneumonia, suggesting its improvement in performance and reliability for routine antimicrobial susceptibility testing in clinical bacteriological laboratories.