RESUMO
Currently, the treatment of infections by Staphylococcus epidermidis (S. epidermidis) represents a challenge because some strains have multidrug-resistance to antimicrobial products (antibiotic and biocides) and can produce biofilms. These biofilms protect bacterial cells from both antimicrobials and the host immune response. Therefore, it is crucial to encourage research on the development of new treatments. One method is immunotherapy, targeting components of S. epidermidis, such as S. epidermidis surface (Ses) proteins. Ses is expressed constitutively in most strains, and they participate in biofilm formation. This review is an update on Ses, regarding their structure, biological function, their relationship with S. epidermidis biofilm formation, and its possible role as therapeutic targets to develop immunotherapeutic treatments to prevent infections by S. epidermidis.
Assuntos
Antibacterianos , Proteínas de Bactérias , Biofilmes/efeitos dos fármacos , Parede Celular , Staphylococcus epidermidis , Descoberta de Drogas , Humanos , Imunoterapia , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/química , Staphylococcus epidermidis/citologia , Staphylococcus epidermidis/efeitos dos fármacosRESUMO
Bacterial biofilms are involved in various medical infections and food contamination episodes and, for this reason, it is of great importance to developing new strategies of its prevention and control. The subinhibitory concentration of nisin was determined, and its effect against Staphylococcus aureus and Staphylococcus epidermidis biofilms was evaluated. Results obtained by confocal laser microscopy demonstrated morphological changes in the architecture of the structure of biofilms. The main components (polysaccharides, proteins, and extracellular DNA (eDNA)) of the biofilm matrix were determined by spectrophotometry and showed that the formation of staphylococcal biofilms in the presence of nisin results in a less dense matrix structure with modification in its constituents. These results contribute to increase the knowledge of the composition and architecture of the extracellular matrix of biofilms of S. aureus, as well as evidence that the investigation of alternative products to assist in the control and combat of biofilms is a promising strategy.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Nisina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Microscopia Confocal , Staphylococcus aureus/citologia , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Staphylococcus epidermidis/citologia , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/fisiologiaRESUMO
There is a growing quest for an ideal biomaterial that shows appropriate cellular response and is not susceptible to microbial adhesion. In this study, commercial grade II titanium was submitted to RF/DC plasma surface modification at 2.2 mbar, using gas mixtures of argon, nitrogen, and oxygen at proportions 4:1:2 and 4:1:3. The surfaces were physically and chemically characterized. In order to evaluate bacterial response, the surfaces were exposed to Staphylococcus epidermidis. Oxynitrided samples, although having a higher roughness as compared with untreated samples, exhibited lower bacterial growth. This observation is probably due to the formation of different crystalline phases of nitrides and oxides caused by plasma treatment. The surface with highest contact angle and highest surface tension showed lower bacterial adhesion. These results were confirmed by scanning electron microscopy. The role of nitrogen in reducing bacterial adhesion is clear when this material is compared with untreated titanium, on which only an oxide film is present.
Assuntos
Aderência Bacteriana , Materiais Biocompatíveis/química , Gases em Plasma/química , Staphylococcus epidermidis/fisiologia , Titânio/química , Biofilmes/crescimento & desenvolvimento , Humanos , Teste de Materiais , Nitrogênio/química , Óxidos/química , Oxigênio/química , Pele/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/citologia , Propriedades de SuperfícieRESUMO
Staphylococcus aureus is the main agent of infections during peritoneal dialysis (PD). The presence of S. aureus in the nasal cavity has been extensively studied and suggested as a risk factor of dialysis-related infections, whereas coagulase-negative Staphylococcus (CNS) species are frequently considered part of the normal human microbiota. The aim of this study was to identify Staphylococcus in the nasal cavity, pericatheter skin and peritoneal effluent from PD patients, as well as to evaluate the antimicrobial activity evolution in vitro. Thirty-two chronic PD patients were observed during 12 months and had nasal and pericatheter skin samples collected for culture. When peritonitis was detected, samples were also collected from the peritoneal effluent for culture. The activity of several antimicrobial drugs (penicillin G, oxacillin, cephalothin, ofloxacin, netilmicin and vancomycin) against different Staphylococcus species was measured by using the agar drug diffusion assay (Kirby-Bauer method). Staphylococcus was separated into S. aureus, S. epidermidis and other CNS species in order to determine the in vitro resistance level. S. epidermidis resistance to oxacillin progressively increased during the study period (p < 0.05). Resistance to ofloxacin was inexpressive, whereas resistance to netilmicin and vancomycin was not detected. Of the oxacillin-resistant species (n = 74), 83 percent were S. epidermidis, 13 percent other CNS and 4 percent S. aureus (p < 0.05). Regarding multi-drug resistant strains (n = 45), 82 percent were S. epidermidis, 13 percent other CNS, and 5 percent S. aureus (p < 0.05). This study shows the relevance of resistance to oxacillin and CNS multi-drug resistance, particularly concerning S. epidermidis, in PD patients.(AU)