Virulence Factors and Biofilm Formation in Vancomycin Resistant Enterococcus faecalis and Enterococcus faecium Isolates in Brazil

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.

Biofilm Formation and Virulence Genes in Clinical Isolates of Enterococcus faecalis

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.

Biotechnological Potential of Carotenoids Produced by Extremophilic Microorganisms and Application Prospects for the Cosmetics Industry

Carotenoids are isoprenoid pigments used in food, chemical, textile, pharmaceutical, and cosmetic industries. They act not only as dyes and provitamins A but also have antioxidants, photoprotective, antimicrobial properties, among others. This class of pigment can be obtained traditionally by plants or chemical synthesis, but they have some disadvantages. In recent years, search for alternative sources has been an important strategy for the carotenoid industries. Microbial synthesis is an alternative that has shown good yields, speed, and reduced production costs. Hostile environments, such as the Caatinga domain, represent an interesting source of microorganisms that produce biomolecules, especially carotenoids, because of oxidative stress caused by sunlight. Thus, this region has been attracting the attention of the scientific community and industry for the use of these organisms in the production of carotenoids and applications in cosmetic products;since these compounds have interesting antioxidant and photoprotective properties. In this review, general characteristics of carotenoids, sources of production, industrial applicability, and commercialization will be discussed, as well as perspectives on the production of carotenoids from microorganisms isolated from the Caatinga and their application in anti-UV products.

Phytochemical bioprospecting, antioxidant, antimicrobial and cytotoxicity activities of saline extract from Tithonia diversifolia(Hemsl) A.Gray leaves

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.

In Vitro Evaluation of Gamma Irradiation on a Gel Formulation of Cratylia Mollis: Rheological Proporties and Microbiological Control

Lectin Cramoll-1,4, obtained from Cratylia mollis seeds (beans camaratu) was structurally characterized, biologically and pharmacologically, but its use as a biopharmaceutical is not well documented. The objective of this study is to propose a biopharmaceutical formulation lectin Cramoll-1,4, test their hemagglutinating properties in vitro as well as the use of gamma radiation as a continuous process of decontamination formulation. It was made of the extraction and purification Cramoll-1,4, was developed a gel formulation using Carbopol? as a vehicle, at concentrations of 50, 100, 200, 300 and 600 μg was irradiated with 60Co gamma rays in a dose of 7.549 kGy·h–1. The proposed formulation at a concentration of 300 μg produced an increase in the hemagglutinating units Cramoll-1,4 due to the synergistic effect caused by gamma radiation. Considering the diverse use of lectins, specific molecular and structural factors, as well as changes resulting from its formulation, concentration, irradiation and route of administration is of utmost importance to continue the studies in vitro, for subsequent application in vivo to characterize the physiological and molecular processes involved in the response and cellular effects.

Stability of the Antioxidant Activity of Flavonoids after Gamma Irradiation

Food irradiation has the purpose of destroying insects or microorganisms, thereby increasing the safety and shelf life of foods. Flavonoids are ubiquitous plant secondary products with radical scavenger ability. In the present study their antioxidant stability after gamma irradiation was evaluated. The flavonoids showed fast scavenger ability measured with the 2.2-diphenyl-1-picrylhydrazyl radical (DPPH) after high doses of radiation. The low damage caused by irra- diation on antioxidant capacity of the flavonoids shows their potential use in combating chemical oxidation of bio- molecules in irradiated foods.