Brasil
| Artigo
Reduced susceptibility to vancomycin and biofilm formation in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures
Registro en:
Memórias do Instituto Oswaldo Cruz. Instituto Oswaldo Cruz, Ministério da Saúde, v. 109, n. 7, p. 871-878, 2014.
0074-0276
10.1590/0074-0276140120
S0074-02762014000700871
S0074-02762014000700871.pdf
0115647772315973
Autor
Pinheiro, Luiza
Brito, Carla Ivo
Pereira, Valéria Cataneli
Oliveira, Adilson De
Camargo, Carlos Henrique
Cunha, Maria De Lourdes Ribeiro De Souza Da
Resumen
This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec) type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC) was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with an MIC of 16 μg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Universidade Estadual Paulista Instituto de Biociências de Botucatu Departamento de Microbiologia e Imunologia Universidade Estadual Paulista Instituto de Biociências de Botucatu Departamento de Microbiologia e Imunologia