Enterococcus faecalis is a Gram-positive bacterium commonly found in the gastrointestinal tract that can cause serious infections. Many enterococci have broad resistance to antibiotics including penicillin, cephalospo...Enterococcus faecalis is a Gram-positive bacterium commonly found in the gastrointestinal tract that can cause serious infections. Many enterococci have broad resistance to antibiotics including penicillin, cephalosporins, aminoglycosides and glycopeptides. There are several adaptation mechanisms that bacteria can undergo to become more resistant, among them is the formation of biofilm. Several genes have been linked to the increase in the capacity of biofilm formation by bacteria such as gelE, esp and asa1. The aim of this research was to evaluate the biofilm formation of 12 E. faecalis isolates collected in hospitals and a standard strain, as well as to evaluate the hydrophobicity of its membrane and the presence of virulence genes. All the isolates formed biofilm and the characteristics of their membrane were variable. In addition, the presence of at least one virulence gene was found in all the 12 isolates, and none of the genes in the standard strain, indicating the acquisition of these genes in the hospital environment. With this, we can conclude that there is a close relationship between biofilm formation, acquisition of antibiotic resistance and the presence of virulence genes.展开更多
In this work, we evaluated biofilm formation of Vancomycin Resistant of E. faecalis and E. faecium (VRE) in different culture media and adhesion substrate, as well as cellular hydrophobicity and presence of virulence ...In this work, we evaluated biofilm formation of Vancomycin Resistant of E. faecalis and E. faecium (VRE) in different culture media and adhesion substrate, as well as cellular hydrophobicity and presence of virulence genes. For this, 35 isolates were collected from a public hospital in Recife, Pernambuco, Brazil and identified by the Matrix-Assisted Laser Desorption Ionization - Time-of-flight - Mass Spectrometry (MALDI-TOF-MS) technique. Biofilm formation was analyzed by the Crystal Violet (CV) method and fluorescence microscopy, cellular hydrophobicity by hydrocarbon interaction and the presence of gelE, esp and asa1 genes by Polymerase Chain Reaction (PCR). 12 isolates were identified as E. faecalis and 23 as E. faecium. Most were obtained in Coronary Units (40.0%) and Intensive Care Unit (31.4%). E. faecium isolates were more resistant to the antibiotics tested than E. faecalis;however, E. faecalis stood out as a biofilm producer. Regarding the presence and gene frequency, it was observed that gelE (54.3%) and esp (54.3%) were the most prevalent, followed by asa1 (22.9%). When comparing the gene frequency, it was observed that gelE and esp were predominant (48.6% for both species), while asa1 was more frequent in E. faecalis (20.0%). The data presented here are worrying, because they reveal the virulence potential of isolates VRE, which contributes to the dissemination and persistence of these pathogens in the hospital environment.展开更多
Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline ext...Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline extract was prepared,with NaCl(0.15 M),by constant stirring of the dried and pulverized leaves,followed by volume reduction by lyophilization.The extract was phytochemical characterized using ultra-performance liquid chromatography,and total phenol and flavonoid analysis also was performed.The antioxidant capacity was determined through DPPH*radical,the antimicrobial property was evaluated against standard bacteria and fungi,and the viability assays were performed against mice splenocytes.Results:Fifteen compounds were identified belonging to two main classes terpenoids and phenolics.The extract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid.Moreover,extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule[(3.042±0.019)mg AAE/g and(4.12±0.10)mg AAE/g to saline extract and butylated hydroxytoluene,respectively].The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes,in concentrations lower than 50μg/mL,promoting higher proliferation in these cells.Conclusions:Saline extract from Tithonia diversifolia leaves presents potential antioxidant,antifungal properties and induces immunostimulation in mice splenocytes.展开更多
文摘Enterococcus faecalis is a Gram-positive bacterium commonly found in the gastrointestinal tract that can cause serious infections. Many enterococci have broad resistance to antibiotics including penicillin, cephalosporins, aminoglycosides and glycopeptides. There are several adaptation mechanisms that bacteria can undergo to become more resistant, among them is the formation of biofilm. Several genes have been linked to the increase in the capacity of biofilm formation by bacteria such as gelE, esp and asa1. The aim of this research was to evaluate the biofilm formation of 12 E. faecalis isolates collected in hospitals and a standard strain, as well as to evaluate the hydrophobicity of its membrane and the presence of virulence genes. All the isolates formed biofilm and the characteristics of their membrane were variable. In addition, the presence of at least one virulence gene was found in all the 12 isolates, and none of the genes in the standard strain, indicating the acquisition of these genes in the hospital environment. With this, we can conclude that there is a close relationship between biofilm formation, acquisition of antibiotic resistance and the presence of virulence genes.
文摘In this work, we evaluated biofilm formation of Vancomycin Resistant of E. faecalis and E. faecium (VRE) in different culture media and adhesion substrate, as well as cellular hydrophobicity and presence of virulence genes. For this, 35 isolates were collected from a public hospital in Recife, Pernambuco, Brazil and identified by the Matrix-Assisted Laser Desorption Ionization - Time-of-flight - Mass Spectrometry (MALDI-TOF-MS) technique. Biofilm formation was analyzed by the Crystal Violet (CV) method and fluorescence microscopy, cellular hydrophobicity by hydrocarbon interaction and the presence of gelE, esp and asa1 genes by Polymerase Chain Reaction (PCR). 12 isolates were identified as E. faecalis and 23 as E. faecium. Most were obtained in Coronary Units (40.0%) and Intensive Care Unit (31.4%). E. faecium isolates were more resistant to the antibiotics tested than E. faecalis;however, E. faecalis stood out as a biofilm producer. Regarding the presence and gene frequency, it was observed that gelE (54.3%) and esp (54.3%) were the most prevalent, followed by asa1 (22.9%). When comparing the gene frequency, it was observed that gelE and esp were predominant (48.6% for both species), while asa1 was more frequent in E. faecalis (20.0%). The data presented here are worrying, because they reveal the virulence potential of isolates VRE, which contributes to the dissemination and persistence of these pathogens in the hospital environment.
文摘Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline extract was prepared,with NaCl(0.15 M),by constant stirring of the dried and pulverized leaves,followed by volume reduction by lyophilization.The extract was phytochemical characterized using ultra-performance liquid chromatography,and total phenol and flavonoid analysis also was performed.The antioxidant capacity was determined through DPPH*radical,the antimicrobial property was evaluated against standard bacteria and fungi,and the viability assays were performed against mice splenocytes.Results:Fifteen compounds were identified belonging to two main classes terpenoids and phenolics.The extract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid.Moreover,extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule[(3.042±0.019)mg AAE/g and(4.12±0.10)mg AAE/g to saline extract and butylated hydroxytoluene,respectively].The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes,in concentrations lower than 50μg/mL,promoting higher proliferation in these cells.Conclusions:Saline extract from Tithonia diversifolia leaves presents potential antioxidant,antifungal properties and induces immunostimulation in mice splenocytes.
