title: Comparison of Etest, Vitek and agar dilution for susceptibility testing of colistin.
abstract: In total, 172 isolates of Enterobacteriaceae, Acinetobacter spp., Pseudomonas aeruginosa and Stenotrophomonas maltophilia were tested for susceptibility to colistin by agar dilution, Etest and the Vitek 2 system. Isolates with a colistin MIC < or =2 mg/L were considered to be susceptible. Fifty-four (31%) Gram-negative isolates were resistant to colistin. Categorical agreement between agar dilution and Etest was 87%, and between agar dilution and Vitek 2 was 82%. Based on the data obtained, the Vitek 2 system was unreliable for detecting colistin resistance, and results obtained by Etest may require confirmation by a standard MIC susceptibility testing method.
authors: Laboratory Medicine Services, Changi General Hospital, Singapore. thean_yen_tan@cgh.com.sg
authors: T Y
authors: TY
authors: Tan
authors: S Y
authors: SY
authors: Ng
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects; D016946:Gram-Negative Aerobic Rods and Cocci / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000295:instrumentation* / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin