RESUMO
The ability of antibiotic resistant E. faecalis and E. faecium isolated from food to form biofilm at different temperatures in the absence or presence of 0.75% glucose was evaluated. A synergistic effect on biofilm at 10 °C, 28 °C, 37 °C and 45 °C and glucose was observed for E. faecalis and E. faecium.
Assuntos
Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana , Enterococcus faecalis/fisiologia , Enterococcus faecium/fisiologia , Microbiologia de Alimentos , Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/isolamento & purificação , Enterococcus faecalis/efeitos da radiação , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/efeitos da radiação , Glucose/metabolismo , Poliestirenos , TemperaturaRESUMO
Enterococcus faecium has emerged as one of the most important pathogens in healthcare-associated infections worldwide due to its intrinsic and acquired resistance to many antibiotics, including vancomycin. Antimicrobial photodynamic therapy (aPDT) is an alternative therapeutic platform that is currently under investigation for the control and treatment of infections. PDT is based on the use of photoactive dye molecules, widely known as photosensitizer (PS). PS, upon irradiation with visible light, produces reactive oxygen species that can destroy lipids and proteins causing cell death. We employed Galleria mellonella (the greater wax moth) caterpillar fatally infected with E. faecium to develop an invertebrate host model system that can be used to study the antimicrobial PDT (alone or combined with antibiotics). In the establishment of infection by E. faecium in G. mellonella, we found that the G. mellonella death rate was dependent on the number of bacterial cells injected into the insect hemocoel and all E. faecium strains tested were capable of infecting and killing G. mellonella. Antibiotic treatment with ampicillin, gentamicin or the combination of ampicillin and gentamicin prolonged caterpillar survival infected by E. faecium (Pâ=â0.0003, Pâ=â0.0001 and Pâ=â0.0001, respectively). In the study of antimicrobial PDT, we verified that methylene blue (MB) injected into the insect followed by whole body illumination prolonged the caterpillar survival (Pâ=â0.0192). Interestingly, combination therapy of larvae infected with vancomycin-resistant E. faecium, with antimicrobial PDT followed by vancomycin, significantly prolonged the survival of the caterpillars when compared to either antimicrobial PDT (Pâ=â0.0095) or vancomycin treatment alone (Pâ=â0.0025), suggesting that the aPDT made the vancomycin resistant E. faecium strain more susceptible to vancomycin action. In summary, G. mellonella provides an invertebrate model host to study the antimicrobial PDT and to explore combinatorial aPDT-based treatments.
Assuntos
Antibacterianos/uso terapêutico , Modelos Animais de Doenças , Enterococcus faecium/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Azul de Metileno/uso terapêutico , Mariposas/microbiologia , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Enterococcus faecium/efeitos da radiação , Mariposas/efeitos da radiação , FotoquimioterapiaRESUMO
The ability of antibiotic resistant E. faecalis and E. faecium isolated from food to form biofilm at different temperatures in the absence or presence of 0.75% glucose was evaluated. A synergistic effect on biofilm at 10 °C, 28 °C, 37 °C and 45 °C and glucose was observed for E. faecalis and E. faecium.