Metallo‐β‐lactamase‐producing Enterobacteriaceae isolates at a Taiwanese hospital: lack of distinctive phenotypes for screening
Abstract:Liao I‐C, Chen H‐M, Wu J‐J, Tsai P‐F, Wang L‐R, Yan J‐J. Metallo‐β‐lactamase‐producing Enterobacteriaceae isolates at a Taiwanese hospital: lack of distinctive phenotypes for screening. APMIS 2011; 119: 543–50.
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.
Document Type: Research Article
Publication date: August 1, 2011