Metallo-β-lactamase-production in meropenem-susceptible Pseudomonas aeruginosa isolates: risk for silent spread
Mem. Inst. Oswaldo Cruz
; 107(6): 747-751, set. 2012. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-649489
Biblioteca responsável:
BR1.1
ABSTRACT
The aim of this study was to characterize two metallo-β-lactamases (MBLs)-producing Pseudomonas aeruginosa clinical isolates showing meropenem susceptibility. Antimicrobial susceptibility was assessed by automated testing and Clinical and Laboratory Standards Institute agar dilution method. MBL production was investigated by phenotypic tests. Molecular typing was determined by pulsed field gel electrophoresis (PFGE). MBL-encoding genes, as well as their genetic context, were identified by polymerase chain reaction (PCR) and sequencing. The location of blaIMP-16 was determined by plasmid electrophoresis, Southern blot and hybridization. Transcriptional levels of blaIMP-16, mexB, mexD, mexF, mexY, ampC and oprD were determined by semi-quantitative real time PCR. The P. aeruginosa isolates studied, Pa30 and Pa43, showed imipenem and meropenem susceptibility by automated testing. Agar dilution assays confirmed meropenem susceptibility whereas both isolates showed low level of imipenem resistance. Pa30 and Pa43 were phenotypically detected as MBL producers. PFGE revealed their clonal relatedness. blaIMP-16 was identified in both isolates, carried as a single cassette in a class 1 integron that was embedded in a plasmid of about 60-Kb. Pa30 and Pa43 overexpressed MexAB-OprM, MexCD-OprJ and MexXY-OprM efflux systems and showed basal transcriptional levels of ampC and oprD. MBL-producing P. aeruginosa that are not resistant to meropenem may represent a risk for therapeutic failure and act as silent reservoirs of MBL-encoding genes.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Pseudomonas aeruginosa
/
Beta-Lactamases
/
Tienamicinas
/
Imipenem
/
Resistência beta-Lactâmica
/
Antibacterianos
Tipo de estudo:
Estudo de etiologia
/
Guia de prática clínica
/
Fatores de risco
Limite:
Humanos
Idioma:
Inglês
Revista:
Mem. Inst. Oswaldo Cruz
Assunto da revista:
Medicina Tropical
/
Parasitologia
Ano de publicação:
2012
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Brasil
Instituição/País de afiliação:
Universidade Estadual de Londrina/BR
/
Universidade Estadual de Maringá/BR
/
Universidade Federal de São Paulo/BR