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

Keizo Yamaguchi, Yoshikazu Ishii, Yoshihisa Itoh, Mitsuo Kaku, Tatsuo Yamamoto, Yoshio Kobayashi, Shigemi Kondoh, Hisashi Baba, Satoshi Ichiyama, Kiyoharu Yamanaka, Nobuchika Kusano, Hitoshi Miyamoto, Tetsuro Matsumoto, Shigeru Kohno

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1 Citation (Scopus)


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.

Original languageEnglish
Pages (from-to)177-187
Number of pages11
JournalJapanese Journal of Chemotherapy
Issue number2
Publication statusPublished - Mar 2011
Externally publishedYes


  • Antibacterial activity
  • Post-marketing surveillance
  • Tazobactam/piperacillin

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)


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