Vol.58 No.6 November 2010

In vitro antibacterial activity of pazufloxacin against clinical isolates from 2002 to 2007

Yoko Sugiura, Naoko Futakuchi, Harumi Hisada, Yuko Ito, Kyoko Hasegawa, Yuri Furuya, Yuko Shinmura, Kazuya Itadani, Masatoshi Nakatani, Yoshiko Fukuda, Nobuhiko Nomura and Junichi Mitsuyama

Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama, Japan

Abstract

We evaluated the in vitro antibacterial activity of the intravenous quinolone, pazufloxacin(PZFX) against clinical strains isolated from 2002 to 2007 in Japan, and compared it to that against clinical isolates before 2001, as previously reported. MIC₉₀ of PZFX against Gram-positive bacteria was 3.13->100 μg/mL and that against Gram-negative bacteria was 0.025-50 μg/mL, almost similar to those of ciprofloxacin(CPFX).
Although MIC₉₀ (12.5 μg/mL) of PZFX against Escherichia coli increased in the same manner as that of CPFX, MIC₉₀s of PZFX against major pathogens of pneumonia and sepsis were almost similar to those against clinical isolates before 2001. For major pneumonia pathogens, such as Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, and for major sepsis pathogens, such as Staphylococcus aureus, E. coli, Citrobacter freundii, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa, the PZFX-susceptible rate calculated from theoretical breakpoints of PZFX 1,000 mg b.i.d. in pneumonia was more than 98.7% and that in sepsis was 83.1% as determined by the Japanese Society of Chemotherapy.
In conclusion, PZFX showed potent in vitro antibacterial activity against clinical isolates in 2002 to 2007. Although the ratio of resistant to quinolone increased in some species of major pathogens of pneumonia and sepsis, the antibacterial activity of PZFX comparable to those against clinical isolates before 2001.

Key word

pazufloxacin, MIC

Received

August 2, 2010

Accepted

September 1, 2010

Jpn. J. Chemother. 58 (6): 681-687, 2010