RESUMO
In this study, we investigated the frequency of isolates included in the susceptible-dose dependent (SDD) category, according to the Clinical and Laboratory Standards Institute guidelines, carrying blaTEM, blaSHV and blaCTX genes among 92 Klebsiella pneumoniae and 80 Enterobacter cloacae clinical isolates. The presence of one or more extended-spectrum ß-lactamases (ESBLs) genes was observed in 64% K. pneumoniae and 69% E. cloacae isolates. Nineteen isolates were included in SDD interpretive category criteria, of which 15 carried ESBL genes (seven K. pneumoniae and eight E. cloacae). Considering the high proportion of ESBL gene-containing isolates included in the SDD category (79%), we recommend that physicians exercise caution in the use of cefepime for treatment of infections caused by these isolates, reducing possible therapeutic failure, particularly in cases of ESBL-producing bacterial strains.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Cefalosporinas/farmacologia , Enterobacter cloacae/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Antibacterianos/efeitos adversos , Antibacterianos/metabolismo , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Brasil , Cefepima , Cefalosporinas/efeitos adversos , Cefalosporinas/metabolismo , Cefalosporinas/uso terapêutico , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae/classificação , Enterobacter cloacae/enzimologia , Enterobacter cloacae/crescimento & desenvolvimento , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Genes Bacterianos , Humanos , Inativação Metabólica , Unidades de Terapia Intensiva , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Tipagem Molecular , Guias de Prática Clínica como Assunto , beta-Lactamases/genéticaRESUMO
INTRODUCTION: The aim of this study was to identify a rapid and simple phenotypic method for extended-spectrum ß-lactamase (ESBL) detection in Enterobacter cloacae. METHODS: A total of 79 consecutive, non-repeated samples of E. cloacae were evaluated. Four phenotypic methods were applied for ESBL detection, results were compared to multiplex polymerase chain reaction (PCR) as the gold standard reference method: 1) ceftazidime and cefotaxime disks with and without clavulanate, both with boronic acid added; 2) disk approximation using cefepime and amoxicillin/clavulanate; 3) ESBL screening by minimum inhibitory concentration (MIC) ≥ 16µg/mL and 4) by MIC ≥ 2µg/mL for cefepime. RESULTS: Method 4 showed the best combination of sensitivity (100%) and specificity (94%). CONCLUSIONS: MIC ≥ 2µg/mL for cefepime would be very useful for the phenotypic detection of ESBL in samples of E. cloacae.
