Tentative inhibition zone criteria (Bauer-Kirby agar disk diffusion method) for rifampin against staphylococci.
Two of 359 (0.6%) clinical isolates of Staphylococcus aureus and 12 of 218 (5.5%) clinical isolates of coagulase-negative staphylococci were resistant or of intermediate susceptibility against rifampin as based on minimal inhibitory concentration (MIC) breakpoints obtained with the agar dilution method: MIC greater than or equal to 2 micrograms/ml = resistant; MIC 0.25-1 microgram/ml = intermediate susceptible; MIC less than 0.125 microgram/ml = susceptible. The following inhibition zone criteria with 2 micrograms rifampin disks were proposed for staphylococcal isolates utilizing the Bauer-Kirby agar disk diffusion test: diameter of inhibition zones less than or equal to 13 mm = resistant; diameter 14-21 mm = intermediate susceptible; diameter greater than or equal to 22 mm = susceptible.
Institut für Medizinische Mikrobiologie und Hygiene, Universität des Saarlandes, Homburg a.d. Saar, FRG.
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Traub
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Spohr
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Bauer
D004352:Drug Resistance, Microbial; D012293:Rifampin / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics
D012293:Rifampin