Author(s): Carvalhais, Virgínia Maria Dinis ; Perez-Cabezas, B. ; Oliveira, Cátia ; Vitorino, R. ; Vilanova, Manuel ; Cerca, Nuno
Date: 2018
Persistent ID: https://hdl.handle.net/1822/56413
Origin: RepositóriUM - Universidade do Minho
Subject(s): antibiotics; culturability; dormancy; Staphylococcus epidermidis biofilms; viability; viable but noncultivable cells
AIM: The goal of this study was to determine the effectiveness of antibiotics on Staphylococcus epidermidis biofilms with different proportions of dormant bacteria, using clinical and commensal isolates. MATERIALS & METHODS: The ability of S. epidermidis isolates to develop a dormant state was determined. The susceptibility of biofilms with prevented or induced dormancy to antibiotics was evaluated by enumeration of viable and cultivable cells, and confocal microscopy. RESULTS: Dormancy was observed in the majority of tested strains. Tetracycline and rifampicin enhanced the development of a viable but noncultivable biofilm state. CONCLUSION: Biofilms with induced dormancy were more likely to survive rifampicin. Furthermore, we found that the reduction of cultivable cells was not sufficient to reach definite conclusions on antimicrobial effectiveness.
