Autor(es):
Gomes, F. I. 
; Teixeira, P. ; Cerca, Nuno ; Ceri, H. ; Oliveira, Rosário
Data: 2012
Identificador Persistente: http://hdl.handle.net/1822/22338
Origem: RepositóriUM - Universidade do Minho
Detalhes do Documento
Virulence gene expression by staphylococcus epidermidis biofilm cells exposed t...
Descrição
Staphylococcus epidermidis have become important causes of nosocomial infections, as its pathogenesis is correlated with the ability to form biofilms on polymeric surfaces. Production of poly-N-acetylglucosamine (PNAG) is crucial for S. epidermidis biofilm formation and is synthesized by the gene products of the icaADBC gene cluster. Production of PNAG/polysaccharide intercellular adhesin and biofilm formation are regulated by the alternative sigma factor, σB, and is influenced by a variety of environmental conditions including disinfectants and other antimicrobial substances. The susceptibility of five S. epidermidis strains to antibiotics alone and in double combination was previously tested. Our results demonstrated that some combinations are active and present a general broad spectrum against S. epidermidis biofilms, namely rifampicin–clindamycin and rifampicin–gentamicin. In the present study, it was investigated whether the combination of rifampicin with clindamycin and gentamicin and these antibiotics alone influence the expression of specific genes (icaA and rsbU) of S. epidermidis within biofilms using real-time polymerase chain reaction. The data showed that in most cases the expression of both genes tested significantly increased after exposure to antimicrobial agents alone and in combination. Besides having a similar antimicrobial effect, rifampicin combined with clindamycin and gentamicin induced a lower expression of biofilm-related genes relatively to rifampicin alone. Associated with the advantage of combinatorial therapy in avoiding the emergence of antibiotic resistance, this study demonstrated that it can also cause a lower genetic expression of icaA and rsbU genes, which are responsible for PNAG/polysaccharide intercellular adhesin production, and consequently reduce biofilm formation recidivism, relatively to rifampicin alone.
Staphylococcus epidermidis have become important causes of nosocomial infections, as its pathogenesis is correlated with the ability to form biofilms on polymeric surfaces. Production of poly-N-acetylglucosamine (PNAG) is crucial for S. epidermidis biofilm formation and is synthesized by the gene products of the icaADBC gene cluster. Production of PNAG/polysaccharide intercellular adhesin and biofilm formation are regulated by the alternative sigma factor, σB, and is influenced by a variety of environmental conditions including disinfectants and other antimicrobial substances. The susceptibility of five S. epidermidis strains to antibiotics alone and in double combination was previously tested. Our results demonstrated that some combinations are active and present a general broad spectrum against S. epidermidis biofilms, namely rifampicin–clindamycin and rifampicin–gentamicin. In the present study, it was investigated whether the combination of rifampicin with clindamycin and gentamicin and these antibiotics alone influence the expression of specific genes (icaA and rsbU) of S. epidermidis within biofilms using real-time polymerase chain reaction. The data showed that in most cases the expression of both genes tested significantly increased after exposure to antimicrobial agents alone and in combination. Besides having a similar antimicrobial effect, rifampicin combined with clindamycin and gentamicin induced a lower expression of biofilm-related genes relatively to rifampicin alone. Associated with the advantage of combinatorial therapy in avoiding the emergence of antibiotic resistance, this study demonstrated that it can also cause a lower genetic expression of icaA and rsbU genes, which are responsible for PNAG/polysaccharide intercellular adhesin production, and consequently reduce biofilm formation recidivism, relatively to rifampicin alone.
Tipo de Documento
Artigo
Idioma Inglês
Idioma Inglês
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