The North American component (the United States and Canada) of an International Comparative MIC trial monitoring ofloxacin resistance.

Journal Article (Journal Article;Multicenter Study)

Common lots of reference MIC (minimum inhibitory concentration) method reagents were used to monitor ofloxacin, a newer fluoroquinolone, and 13 other drugs against 3200 recent clinical isolates in February-April 1992. Five medical centers in the United States and Canada contributed 640 strains per facility as follows: Escherichia coli, Staphylococcus aureus, coagulase-negative staphylococci, Klebsiella spp., and Pseudomonas aeruginosa (100 strains each); Streptococcus pneumoniae (40 strains); and Enterobacter cloacae, Serratia marcescens, Salmonella spp., Haemophilus influenzae, and Moraxella catarrhalis (20 strains each). Quality-control strains were processed concurrently, MICs recorded, and data processed at a common location. Selected ofloxacin-resistant isolates were retested at a reference laboratory to confirm resistances and determine cross-resistant patterns. Results indicate the following (a) fluoroquinolones were superior in usable spectrum of activity to other orally administered drugs (for example, cefaclor, cefixime, ampicillin, amoxicillin-clavulanate, minocycline, oxacillin, and trimethoprim-sulfamethoxazole); (b) ofloxacin and ciprofloxacin were generally equal to gentamicin and cefotaxime against commonly isolated Gram-negative pathogens; (c) fluoroquinolone resistance was rare among enteric bacilli, pneumococci (ciprofloxacin > ofloxacin), H. influenzae, and M. catarrhalis, but more common among oxacillin-resistant staphylococci and P. aeruginosa; (d) cross resistance was generally observed between ofloxacin and ciprofloxacin but was species or genus dependent; and (e) a new fluoroquinolone, levofloxacin, demonstrated promising activity against contemporary pathogens.

Full Text

Duke Authors

Cited Authors

  • Hoban, DJ; Jones, RN; Harrell, LJ; Knudson, M; Sewell, D

Published Date

  • August 1993

Published In

Volume / Issue

  • 17 / 2

Start / End Page

  • 157 - 161

PubMed ID

  • 8243037

International Standard Serial Number (ISSN)

  • 0732-8893

Digital Object Identifier (DOI)

  • 10.1016/0732-8893(93)90027-5


  • eng

Conference Location

  • United States