Vol.52 No.12 December 2004

Surveillance of susceptibility of 2,228 clinical isolates to gatifloxacin and various antimicrobial agents

Keizo Yamaguchi¹⁾, Nobuhiko Furuya¹⁾, Morihiro Iwata²⁾, Naoki Watanabe^3,4), Nobuyuki Uehara⁴⁾, Minoru Yasujima⁵⁾, Takeshi Kasai⁶⁾, Mitsuo Kaku⁷⁾, Yuko Abe⁸⁾, Jun Igari⁹⁾, Toyoko Oguri¹⁰⁾, Hisashi Baba¹¹⁾, Hitoshi Yoshimura^12,20), Kiyoharu Yamanaka¹³⁾, Satoshi Ichiyama¹⁴⁾, Nobuchika Kusano¹⁵⁾, Naoko Murao¹⁵⁾, Junko Ono¹⁶⁾, Chika Narita¹⁶⁾, Kaoru Okada¹⁷⁾, Masami Ishida¹⁸⁾, Yoichi Hirakata¹⁹⁾ and Junichi Matsuda¹⁹⁾

¹⁾Department of Microbiology, Toho University School of Medicine, 5-21-16 Omori-nishi, Ota-ku, Tokyo, Japan
²⁾Department of Laboratory Medicine, Toho University Omori Hospital
³⁾Department of Clinical Laboratory Medicine, Sapporo Medical University School of Medicine
⁴⁾Division of Laboratory Diagnosis, Sapporo Medical University Hospital
⁵⁾Department of Laboratory Medicine, Hirosaki University School of Medicine
⁶⁾Department of Clinical Laboratory, Hirosaki University Hospital
⁷⁾Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine
⁸⁾Department of Clinical Medicine, Tohoku University Hospital
⁹⁾Department of Clinical Pathology, Juntendo University School of Medicine
¹⁰⁾Department of Clinical Laboratory, Juntendo University Hospital
¹¹⁾Department of Infectious Diseases, Nagoya University Hospital
¹²⁾Central Laboratories, Mie University School of Medicine
¹³⁾Division of Clinical Laboratory, Otemae Hospital
¹⁴⁾Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine
¹⁵⁾Department of Central Clinical Laboratory, Okayama University Hospital
¹⁶⁾Central Clinical Laboratory, Fukuoka University Hospital
¹⁷⁾Internal Medicine, ¹⁸⁾Microbiology Laboratory, Kitakyusyu Municipal Medical Center
¹⁹⁾Department of Laboratory Medicine, Nagasaki University Hospital of Medicine and Dentistry
²⁰⁾Mie Prefectural Shima Hospital (Present address)

Abstract

In order to examine the activity of fluoroquinolone antibiotics against fresh clinical isolates, we conducted a survey on the susceptibility of 2,228 strains of four gram-positive bacteria and eight gram-negative bacteria to 11 antimicrobials including gatifloxacin (GFLX), during the period from November 2002 to March 2003. These were isolated from sputum, urine, sinus discharge, otorrhea, and middle ear discharge obtained from 15 facilities in Japan. All the isolates were tested in accordance with the National Committee for Clinical Laboratory Standards. The MIC₉₀ of GFLX against penicillin-resistant Streptococcus pneumoniae (PRSP) was 0.5 μ g/mL and its sensitivity rate was also satisfactory at 100%. As in the penicillin-susceptible strains, GFLX exhibited strong antimicrobial activity and good sensitivity against PRSP. MIC₉₀ of GFLX against Haemophilus influenzae was as low as 0.03 μ g/mL and its sensitivity was 99%. The MIC₉₀ of GFLX against Escherichia coli stood at 8 μ g/mL. The MIC₉₀ values of fluoroquinolone antimicrobials against Neisseria gonorrhoeae ranged from 2 μ g/mL to 16 μ g/mL and their sensitivity rates surpassed 90%. On an average, this survey found that fluoroquinolone antimicrobials were very active against Klebsiella pneumoniae, including S. pneumoniae, H. influenzae, and Moraxella catarrhalis. Additionally, GFLX, among others, demonstrated particularly strong bactericidal activity against S. pneumoniae without suffering a decline in drug sensitivity.
Consequently, GFLX could be one of the clinically useful drugs for respiratory infections. On the other hand, it is now evident that E. coli, Enterococci, Pseudomonas aeruginosa, and N. gonorrhoeae have developed more resistance to fluoroquinolone antimicrobials as compared to their previous susceptibility.

Key word

gatifloxacin, antimicrobial activity

Received

October 19, 2004

Accepted

November 24, 2004

Jpn. J. Chemother. 52 (12): 771-786, 2004