Further Modification of the Modified Hodge Test for Detecting Metallo-beta-Lactamase-Producing Carbapenem-Resistant Enterobacteriaceae
Annals of Laboratory Medicine
;
: 298-305, 2015.
Artículo
en Inglés
| WPRIM
| ID: wpr-36810
ABSTRACT
BACKGROUND:
The modified Hodge test (MHT) was designed to detect carbapenemase-producing Enterobacteriaceae (CPE). This study evaluated variables to improve the performance of MHT.METHODS:
Carbapenem-resistant Enterobacteriaceae isolated from November 2010 to March 2013 at the Asan Medical Center, were evaluated, including 33 metallo-beta-lactamase (MBL) producers and 103 non-CPEs. MHT was performed by using two carbapenem disks (ertapenem and meropenem; Becton Dickinson, USA), three media (Mueller-Hinton agar (MHA), MacConkey agar (MAC), and zinc-enriched MHA), and two inoculums (0.5-McFarland [McF] suspension and a 10-fold dilution of it.) PCR was performed to detect beta-lactamase genes of the MBL, AmpC, and CTX-M types.RESULTS:
The sensitivity of MHT for detecting New Delhi metallo-beta-lactamase (NDM) producers was highest using ertapenem and 0.5-McF, 52.0% on MHA and 68.0% on MAC, respectively. NDM-producing Klebsiella pneumoniae (NDMKP) were detected with higher sensitivity on MAC (78.6%) vs. MHA (28.6%) (P=0.016), but VIM-producing Enterobacter, Citrobacter, and Serratia were detected with higher sensitivity on MHA (78.5%) vs. MAC (14.3%) (P=0.004). MBL producers were consistently identified with lower sensitivity using meropenem vs. ertapenem, 39.4% vs. 60.6% (P=0.0156), respectively. The effects of zinc and inoculum size were insignificant. Enterobacter aerogenes producing unspecified AmpC frequently demonstrated false positives, 66.7% with ertapenem and 22.2% with meropenem.CONCLUSIONS:
The MHT should be adjusted for the local distribution of species and the carbapenemase type of MBL producers. MAC and ertapenem are preferable for assessing NDMKP, but MHA is better for VIM. Laboratory physicians should be aware of the limited sensitivity of MHT and its relatively high false-positive rate.
Texto completo:
Disponible
Índice:
WPRIM (Pacífico Occidental)
Asunto principal:
Fenotipo
/
Beta-Lactamasas
/
ADN Bacteriano
/
Carbapenémicos
/
Farmacorresistencia Bacteriana
/
Enterobacteriaceae
/
Infecciones por Enterobacteriaceae
/
Pruebas Antimicrobianas de Difusión por Disco
/
Reacción en Cadena de la Polimerasa Multiplex
/
Antibacterianos
Tipo de estudio:
Estudio pronóstico
Límite:
Humanos
Idioma:
Inglés
Revista:
Annals of Laboratory Medicine
Año:
2015
Tipo del documento:
Artículo
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