Vol.59 No.2 March 2011

Antimicrobial activity of tazobactam/piperacillin against clinical isolates from 2001 to 2006 in Japan

Keizo Yamaguchi¹⁾, Yoshikazu Ishii¹⁾, Yoshihisa Itoh²⁾, Mitsuo Kaku³⁾, Tatsuo Yamamoto⁴⁾, Yoshio Kobayashi⁵⁾, Shigemi Kondoh⁶⁾, Hisashi Baba⁷⁾, Satoshi Ichiyama⁸⁾, Kiyoharu Yamanaka⁹⁾, Nobuchika Kusano¹⁰⁾, Hitoshi Miyamoto¹¹⁾, Tetsuro Matsumoto¹²⁾ and Shigeru Kohno¹³⁾

¹⁾Department of Microbiology and Infectious Diseases, Toho University School of Medicine, 5-21-16 Omori-nishi, Ota-ku, Tokyo, Japan
²⁾Department of Laboratory Medicine, Asahikawa Medical University
³⁾Department of Infection Control and Laboratory, Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine
⁴⁾Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences
⁵⁾Division of Microbiology, Clinical Laboratories, Keio University Hospital
⁶⁾Department of Laboratory Medicine, Juntendo University School of Medicine
⁷⁾Department of Infectious Diseases, Nagoya University School of Medicine
⁸⁾Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine
⁹⁾Division of Clinical Laboratory, Otemae Hospital
¹⁰⁾Department of Central Laboratory, Okayama University Hospital
¹¹⁾Division of Medical Technology, Ehime University Hospital
¹²⁾Department of Urology School of Medicine, University of Occupational and Environmental Health
¹³⁾Second Department of Internal Medicine, Nagasaki University School of Medicine

Abstract

Antimicrobial susceptibility to beta-lactam antibiotics including tazobactam/piperacillin and beta-lactamases production were evaluated for 3,213 clinical isolates of 11 strains, 2 spp., and 1 group obtained from 12 hospitals from 2001 to 2006 in Japan. Susceptibility to tazobactam/piperacillin calculated based on Clinical and Laboratory Standards Institute breakpoints were 59.2%-100%. Tazobactam/piperacillin showed up to 90% susceptibility of 8 strains, 1 sp., and 1 group. Chronological MIC increase of tazobactam/piperacillin was not seen in any species. Isolation frequency of beta-lactamases producing strains increased in Escherichia coli and Serratia marcescens from 68.1% to 97.3% and from 81.0% to 96.2%. Isolation frequency of metallo beta-lactamase(MBL) producing strains increased in Pseudomonas aeruginosa from 5.8% to 8.6%, and those of extended-spectrum beta-lactamases(ESBLs) producing strains also increased in E. coli, Klebsiella pneumoniae and Proteus mirabilis from 1.8% to 6.4%, from 1.1% to 4.7% and from 1.6% to 9.2%. Antimicrobial activity of tazobactam/piperacillin against MBL producing strains was superior to other beta-lactam antibiotics, as were those against ESBLs producing strains for other beta-lactam antibiotics other than flomoxef. Results for tazobactam/piperacillin susceptibility of clinical strains isolated in Japan from 2001 to 2006 showed that tazobactam/piperacillin maintained sufficient antibacterial activity against these strains, including beta-lactamase producing strains, although the isolation frequency of MBL and ESBLs producing strains increased.

Key word

tazobactam/piperacillin, antibacterial activity, post-marketing surveillance

Received

August 31, 2010

Accepted

December 27, 2010

Jpn. J. Chemother. 59 (2): 177-187, 2011