title: Metallo-β-lactamase-producing Enterobacteriaceae isolates at a Taiwanese hospital: lack of distinctive phenotypes for screening.
abstract: We investigated the prevalence of metallo-β-lactamases (MBLs) among 1,827 Enterobacteriaceae isolates collected in 2006 and evaluated the VITEK 2 microbiology system, modified Hodge test, and 2 combined disk tests as the screening tools for MBLs by using these isolates and 77 previously characterized IMP-8 producers. The IMP-8 MBL was identified in 18 isolates of 2006, and the IMP-8-positive isolates represented 0.2%, 1.1%, and 5.0% of all Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae isolates, respectively. Only one-third of all MBL producers could be recognized by either VITEK 2 or the Hodge test. MBL production could be identified in 38 (40%) of the 95 IMP-8-producing isolates by the combined disk test using meropenem disks supplemented by phenylboronic acid and EDTA, and only 2 (2.1%) isolates gave positive results in the combined disk test using meropenem disks supplemented with dipicolinic acid. Of all IMP-8 producers, 37.9%, 50.5%, and 32.6% were nonsusceptible to tigecycline, fluoroquinolones, and both, respectively. In conclusion, this study demonstrated the lack of distinct phenotypes that could be easily identified among the IMP-8-producing Enterobacteriaceae isolates at a Taiwanese hospital. Continuous surveillance and monitoring are needed because the widespread of tigecycline- and fluoroquinolone-coresistant MBL producers may become a serious therapeutic problem.
authors.affiliation: Department of Pathology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: I-Chuang
authors.initials: IC
authors.lastname: Liao
authors.forename: Hung-Mo
authors.initials: HM
authors.lastname: Chen
authors.forename: Jiunn-Jong
authors.initials: JJ
authors.lastname: Wu
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Tsai
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Wang
authors.forename: Jing-Jou
authors.initials: JJ
authors.lastname: Yan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013624:Taiwan; D000078304:Tigecycline; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D000078304:Tigecycline; C436760:IMP-8 enzyme; D001618:beta-Lactamases; D008911:Minocycline