Vol.54 No.4 July 2006
Antimicrobial susceptibility of clinical isolates of aerobic gram-positive cocci and anaerobic bacteria in 2002
Discovery Research Laboratories, Shionogi &, Co., Ltd.,
3-1-1 Futaba-cho, Toyonaka, Osaka, Japan
Abstract
The activities of various antibacterial agents against aerobic gram-positive cocci (28 species, 981 strains) and anaerobic bacteria (21 species, 181 strains), which were isolated from various clinical specimens in 2002 at fifteen clinical facilities in Japan, were studied using either the broth-microdilution or agar-dilution method. The percentages of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis were 58.7% and 84.5%, respectively; these bacteria were isolated at a high frequency. Arbekacin, vancomycin (VCM), and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activities against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of ≤2 μg/mL. The percentage of penicillin (PC) -intermediate and PC-resistant strains among Streptococcus pneumoniae was 81.2%. Among the cephems, cefcapene, cefditoren, cefpirome, and ceftriaxone had MIC90s of ≤1 μg/mL against PC-intermediate and PC-resistant strains. Among the new quinolones, tosufloxacin, gatifloxacin, and moxifloxacin had MIC90s of ≤1 μg/mL against PC-susceptible, PC-intermediate, and PC-resistant strains. VCM and teicoplanin inhibited the growth of all isolates of Enterococcus faecalis and Enterococcus faecium at ≤2 μg/mL, and resistant strains were not detected, suggesting that these agents had good activities against these species. On the other hand, E. faecium strains intermediate or resistant to linezolid or QPR/DPR were found in 5.8% or 15.9% of all strains, respectively. Among the anaerobes, carbapenems showed good activities against Bacteroides spp., Prevotella spp. and Peptostreptococcus spp.. However, since several Bacteroides strains were resistant to them, the susceptibility of this species should be monitored.
Key word
clinical isolate, surveillance, gram-positive cocci, anaerobe, drug susceptibility
Received
March 6, 2006
Accepted
April 10, 2006
Jpn. J. Chemother. 54 (4): 330-354, 2006
