Antimicrobial resistance among clinical isolates of Streptococcus pneumoniae in Canada during 2000.
A total of 2,245 clinical isolates of Streptococcus pneumoniae were collected from 63 microbiology laboratories from across Canada during 2000 and characterized at a central laboratory. Of these isolates, 12.4% were not susceptible to penicillin (penicillin MIC, >or=0.12 microg/ml) and 5.8% were resistant (MIC, >or=2 microg/ml). Resistance rates among non-beta-lactam agents were the following: macrolides, 11.1%; clindamycin, 5.7%; chloramphenicol, 2.2%; levofloxacin, 0.9%; gatifloxacin, 0.8%; moxifloxacin, 0.4%; and trimethoprim-sulfamethoxazole, 11.3%. The MICs at which 90% of the isolates were inhibited (MIC90s) of the fluoroquinolones were the following: gemifloxacin, 0.03 microg/ml; BMS-284756, 0.06 microg/ml; moxifloxacin, 0.12 microg/ml; gatifloxacin, 0.25 microg/ml; levofloxacin, 1 microg/ml; and ciprofloxacin, 1 microg/ml. Of 578 isolates from the lower respiratory tract, 21 (3.6%) were inhibited at ciprofloxacin MICs of >or=4 microg/ml. None of the 768 isolates from children were inhibited at ciprofloxacin MICs of >or=4 microg/ml, compared to 3 of 731 (0.6%) from those ages 15 to 64 (all of these >60 years old), and 27 of 707 (3.8%) from those over 65. The MIC90s for ABT-773 and telithromycin were 0.015 microg/ml for macrolide-susceptible isolates and 0.12 and 0.5 microg/ml, respectively, for macrolide-resistant isolates. The MIC of linezolid was <or=2 microg/ml for all isolates. Many of the new antimicrobial agents tested in this study appear to have potential for the treatment of multidrug-resistant strains of pneumococci.
Low
Donald E
DE
Department of Microbiology, Toronto Medical Laboratories and Mount Sinai Hospital, Toronto, Ontario, Canada. dlow@mtsinai.on.ca
de Azavedo
Joyce
J
Weiss
Karl
K
Mazzulli
Tony
T
Kuhn
Magdalena
M
Church
Deirdre
D
Forward
Kevin
K
Zhanel
George
G
Simor
Andrew
A
McGeer
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D011159:Population Surveillance; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents