title: Evaluation of the Etest method for detecting colistin susceptibility of multidrug-resistant Gram-negative isolates in Vietnam.
abstract: The minimum inhibitory concentrations (MICs) of colistin for 241 multidrug-resistant (MDR) Gram-negative pathogens were determined by the Etest and by the broth microdilution method (BMD). The two methods showed essential agreements of 76% (77/102) for Acinetobacter baumannii, 90% (36/40) for Pseudomonas aeruginosa and 84% (83/99) for Enterobacteriaceae isolates, with categorical agreements of 100%, 98%, and 100%, respectively. Of the 241 isolates, none showed a very major error and one (0.4%) showed a major error. MICs ranged from 0.125 to 0.5 μg/ml for all A. baumannii and most Enterobacteriaceae isolates, and from 1 to 2 μg/ml for most P. aeruginosa isolates. Of the 40 P. aeruginosa isolates, 27 (68%) showed higher colistin MICs by the Etest than by the BMD. In contrast, 77% (78/102) of the A. baumannii and 57% (56/99) of the Enterobacteriaceae isolates showed lower colistin MICs by the Etest than by the BMD. The Etest is a reliable and easy-to-use method to measure colistin MICs of MDR Gram-negative pathogens in clinical laboratories and can be used following validation by microdilution methods.
authors.affiliation: Department of Microbiology, Hanoi Medical University, Viet Nam; Bach Mai Hospital, Hanoi, Viet Nam.
authors.forename: Pham Hong
authors.initials: PH
authors.lastname: Nhung
authors.affiliation: Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Miyoshi-Akiyama
authors.affiliation: Bach Mai Hospital, Hanoi, Viet Nam.
authors.forename: Doan Mai
authors.initials: DM
authors.lastname: Phuong
authors.affiliation: Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Bach Mai Hospital, Hanoi, Viet Nam.
authors.forename: Nguyen Quoc
authors.initials: NQ
authors.lastname: Anh
authors.affiliation: Bach Mai Hospital, Hanoi, Viet Nam.
authors.forename: Nguyen Gia
authors.initials: NG
authors.lastname: Binh
authors.affiliation: Bach Mai Hospital, Hanoi, Viet Nam.
authors.forename: Do Van
authors.initials: do V
authors.lastname: Thanh
authors.affiliation: Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Ohmagari
authors.affiliation: Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan. Electronic address: tkirikae@ri.ncgm.go.jp.
authors.forename: Teruo
authors.initials: T
authors.lastname: Kirikae
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D014744:Vietnam
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin
keywords: Broth microdilution method; Colistin; Etest; Multidrug-resistant Gram-negative pathogen