title: Evaluation of phenotypic tests to detect carbapenem-resistant Enterobacteriaceae in colonized patients hospitalized in intensive care units.
abstract: In this study, we aimed to evaluate the performance of different phenotypic tests to detect carbapenem-resistant Enterobacteriaceae. Three different phenotypic methods were evaluated: (1) combined-disk test of meropenem plus phenylboronic acid or EDTA reading after 24h and 48h; (2) selective/chromogenic read after 24h and after 48h; and (3) overnight selective enrichment broth containing 10μg ertapenem disk followed by culture on MacConkey agar. A positive result in at least one of the methods was submitted to PCR for blaNDM-1, blaOXA-48, blaKPC, blaSPM-1, blaIMP, and blaGES detection. Carbapenem-resistant Enterobacteriaceae was detected in 31 (30.4%) of 102 rectal swabs evaluated. All isolates showed to be KPC-2-producing organisms. Results showed excellent agreement among the evaluated tests (positive and negative) (kappa=0.88). It is important to state that combined-disk test with phenylboronic acid is not suitable for bacterial identification/isolation. Conversely, selective/chromogenic agar after 48h of incubation showed to be a useful tool, with the advantage of presumptive bacterial identification.
authors.affiliation: Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratório de Pesquisa em Resistência Bacteriana (LABRESIS), Centro de Pesquisa Experimental (CPE), Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Hospital Mãe de Deus, Porto Alegre, RS, Brazil. Electronic address: leandro.reus@gmail.com.
authors.forename: Leandro Reus Rodrigues
authors.initials: LR
authors.lastname: Perez
authors.affiliation: Hospital Mãe de Deus, Porto Alegre, RS, Brazil.
authors.forename: Diógenes
authors.initials: D
authors.lastname: Rodrigues
authors.affiliation: Hospital Mãe de Deus, Porto Alegre, RS, Brazil; Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Cícero Gomes
authors.initials: CG
authors.lastname: Dias
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods; D015780:Carbapenems / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D006801:Humans; D007362:Intensive Care Units; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D015780:Carbapenems; D001618:beta-Lactamases
keywords: Carbapenems; Enterobacteriaceae; KPC; Surveillance