Vol.55 No.S-1 October 2007
Clinical response of garenoxacin against respiratory tract infection and otorhinolaryngological infection caused by multidrug-resistant Streptococcus pneumoniae
1)Division of Molecular and Clinical Microbiology, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, Japan
2)Kyorin University School of Medicine
3)Nagoya City University Medical School
4)Research Laboratories, Toyama Chemical Co., Ltd.
Abstract
Subjects with infection caused by Streptococcus pneumoniae were chosen from eight studies of garenoxacin mesilate hydrate(GRNX), a novel oral des-fluoroquinolone, for treatment against respiratory tract infection and otorhinolaryngological infection. Susceptibility to antimicrobial agents, gene analysis of penicillin binding protein(PBP) mutation and macrolide-resistant genes, and clinical response against multidrug-resistant S. pneumoniae were evaluated for subjects. In 130 S. pneumoniae isolates as causative organisms from subjects treated by GRNX, the incidence of penicillin-resistant S. pneumoniae(PRSP) and penicillin-intermediate resistant S. pneumoniae(PISP) were 20.8% (27/130) and 26.2% (34/130). 106 S. pneumoniae susceptibility tests were redone to examine the degree of resistance to antimicrobial agents. MIC90 values of antimicrobial agents against 106 S. pneumoniae were 0.125 μg/mL for GRNX, 2 μg/mL for levofloxacin, 0.5 μg/mL for gatifloxacin, 0.25 μg/mL for moxifloxacin, 8 μg/mL for cefuroxime, >128 μg/mL for erythromycin, >128 μg/mL for azithromycin, 0.25 μg/mL for telithromycin, 64 μg/mL for tetracycline and 2 μg/mL for sulfamethoxazole-trimethoprim(ST). Among these antimicrobial agents, GRNX showed the strongest activity. In 106 S. pneumoniae isolates, 2.8% (3/106) were quinolone-resistant, 44.3% (47/106) were β-lactam-resistant, 79.2% (84/106) were macrolide-resistant, 80.2% (85/106) were tetracycline-resistant, 9.4% (10/106) were ST resistant, and 78.3% (83/106) were multidrug-resistant. In the 72 isolates of PRSP and PISP isolated from all clinical studies in spite of GRNX treatment/notreatment, pbp1a+pbp2x+pbp2b mutation (39/72) regarding PBP and ermB presence (33/72) regarding the macrolide-resistant gene were observed most frequently. Against infections caused by multidrug-resistant S. pneumoniae, GRNX showed good clinical response as 96.4% (80/83) for clinical efficacy and 100% (81/81) for bacterial eradication.
Key word
garenoxacin, des-fluoro(6)-quinolone, multidrug-resistant Streptococcus pneumoniae
Received
June 13, 2007
Accepted
July 26, 2007
Jpn. J. Chemother. 55 (S-1): 222-230, 2007
