Vol.54 No.4 July 2006
Antimicrobial susceptibility of clinical isolates of aerobic gram-negative bacteria in 2002
Discovery Research Laboratories, Shionogi & Co., Ltd.,
3-1-1 Futaba-cho, Toyonaka, Osaka, Japan
Abstract
We determined the MICs of various antibacterial agents against 1,163 clinical strains of aerobic gram-negative bacteria (19 genus or species) isolated at fifteen Japanese facilities in 2002. The MICs were determined using mostly the broth microdilution method, and the activities of the agents were assessed. The antibacterial susceptibilities of Enterobacteriaceae to most β-lactams were comparable to those described in our previous report on isolates obtained in 2000; however, the percentages of new-quinolones (NQs)-intermediate or NQs-resistant strains increased. Strains producing extended-spectrum β-lactamases accounted for 1.4% of the Escherichia coli, 1.5% of the Klebsiella spp., and 8.1% of the Proteus spp.. Most antibacterial agents showed good activities against Moraxella catarrhalis. On the other hand, the percentage of NQs-intermediate or NQs-resistant strains among Neisseria gonorrhoeae was high at 87%, similar to the results reported in 2000. β-lactamase-producing and β-lactamase-negative ampicillin-resistant strains accounted for 6% and 50% of Haemophilus influenzae isolates, respectively. The activities of most antibacterial agents against Pseudomonas aeruginosa were lower than those in 2000, whereas only doripenem showed an MIC90 of 8 μg/mL. The strains resistant to seven or more agents among ten anti-pseudomonal agents accounted for 14.4%. Against other glucose-non-fermentative gram-negative bacteria, the activities of most antibacterial agents, including NQs, were lower than those in 2000.
Key word
clinical isolate, surveillance, gram-negative bacteria, multi-drug-resistant Pseudomonas aeruginosa, drug susceptibility
Received
March 6, 2006
Accepted
April 10, 2006
Jpn. J. Chemother. 54 (4): 355-377, 2006
