title: Validation and reproducibility assessment of tigecycline MIC determinations by Etest.
abstract: A multicenter study was conducted to validate Etest tigecycline compared to the Clinical Laboratory Standards Institute reference broth microdilution and agar dilution methodologies. A large collection of gram-negative (n = 266) and gram-positive (n = 162) aerobic bacteria, a collection of anaerobes (n = 385), and selected collections of nonpneumococcal streptococci (n = 369), Streptococcus pneumoniae (n = 372), and Haemophilus influenzae (n = 372) were tested. Strains with reduced susceptibility to tigecycline were used with all test methods. The Etest showed excellent inter- and intralaboratory reproducibility for all organism groups tested regardless of the test methodology. The essential agreement values with the reference method (+/-1 dilution) were >99% for the collection of gram-negative and gram-positive aerobes; >98% for the S. pneumoniae, H. influenzae, and anaerobe collections; and 100% for the group of nonpneumococcal streptococci. These results validate the performance accuracy and utility of Etest tigecycline and verify the reproducibility of this convenient predefined gradient methodology for tigecycline susceptibility determination.
authors.affiliation: AB BIODISK, Solna, Sweden.
authors.forename: Anne
authors.initials: A
authors.lastname: Bolmström
authors.forename: Asa
authors.initials: A
authors.lastname: Karlsson
authors.forename: Anette
authors.initials: A
authors.lastname: Engelhardt
authors.forename: Phion
authors.initials: P
authors.lastname: Ho
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Petersen
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Bradford
authors.forename: C Hal
authors.initials: CH
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D015203:Reproducibility of Results; D000078304:Tigecycline
chemical_list: D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D008911:Minocycline