In vitro activities of fluoroquinolones against antibiotic-resistant blood culture isolates of viridans group streptococci from across Canada.
Among 418 blood culture isolates of viridans group streptococci obtained between 1995 and 1997, the in vitro rates of nonsusceptibility to penicillin, erythromycin, tetracycline, and trimethoprim-sulfamethoxazole were 28, 29, 24, and 14%, respectively. The most prevalent group (125 strains) was Streptococcus mitis, followed by Streptococcus sanguis (56 strains). For 236 (56%) strains resistant to one or more antibiotics, the ciprofloxacin MIC at which 90% of the isolates were inhibited (MIC(90)) was 4 microg/ml, whereas the MIC(90)s of trovafloxacin, grepafloxacin, and gatifloxacin were 0.25 microg/ml.
de Azavedo
J C
JC
Department of Microbiology, Mount Sinai and Princess Margaret Hospitals, University of Toronto, Toronto, Ontario, Canada. jdeazavedo@mtsinai.on.ca
Trpeski
L
L
Pong-Porter
S
S
Matsumura
S
S
Low
D E
DE
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002170:Canada; D004352:Drug Resistance, Microbial; D024841:Fluoroquinolones; D006801:Humans; D008826:Microbial Sensitivity Tests; D013291:Streptococcus / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification
D000890:Anti-Infective Agents; D024841:Fluoroquinolones