Search results for "microbiology"

Time-kill assays of amphotericin B plus anidulafungin against Candida tropicalis biofilms formed on two different biomaterials.

2017

Purpose: To determine the fungicidal activity by time-killing assays of amphotericin B (AMB) combined with anidulafungin (ANF) against biofilms of 2 clinical isolates of Candida tropicalis and the reference strain ATCC® 750, developed on polytetrafluoroethylene (PTFE) and titanium, using the CDC Biofilm Reactor (CBR) as an in vitro model. Methods: Biofilms were developed for 24 hours on the disk surfaces and then exposed to AMB (40 mg/L), ANF (8 mg/L), alone and combined. At predetermined time points after drug exposure, biofilms were removed from the disk surface by vortexing-sonication to quantify viable biofilm cells. Results: Drug activity was dependent on strain and time. After exposur…

Aspergilosis invasora en el paciente con enfermedad oncohematológica

2018

Invasive aspergillosis is the most common invasive fungal infection in patients with acute hematological malignancies or treated with hematopoietic stem cell transplantation due to the marked alteration of the physiological mechanisms of antifungal immunity that takes place in these situations. For this reason, antifungal prophylaxis has a relevant role in these patients. The introduction of new antifungal agents has motivated the updating of recommendations for prophylaxis and treatment in different guidelines. The objectives of this chapter are a brief review of the mechanisms of immunity against fungi, the definition of risk for developing an invasive fungal infection and an update of th…

Untargeted Antifungal Treatment in Nonneutropenic Critically Ill Patients: Should Further Studies Be Performed Based on Trial Sequential Analysis Res…

2018

Dying with or because of invasive fungal infection? The role of immunity exhaustion on patient outcome

2016

De Rosa et al. considered clinical scores, biomarkers and their combination as useful aids for an early antifungal treatment and advocated the adoption of de-escalation therapy in an antifungal stewardship approach as a possible key for a better management of these patients. Authors considered the high burden of invasive fungal infections in terms of patient outcomes and costs and focused on current strategies for their optimization.

Pleomorphic forms of Borrelia burgdorferi induce distinct immune responses.

2016

Borrelia burgdorferi is the causative agent of tick-borne Lyme disease. As a response to environmental stress B. burgdorferi can change its morphology to a round body form. The role of B. burgdorferi pleomorphic forms in Lyme disease pathogenesis has long been debated and unclear. Here, we demonstrated that round bodies were processed differently in differentiated macrophages, consequently inducing distinct immune responses compared to spirochetes in vitro. Colocalization analysis indicated that the F-actin participates in internalization of both forms. However, round bodies end up less in macrophage lysosomes than spirochetes suggesting that there are differences in processing of these for…

Analysis of the 3H8 antigen of Candida albicans reveals new aspects of the organization of fungal cell wall proteins.

2017

The walls of both, yeast and mycelial cells of Candida albicans possess a species-specific antigen that is recognized by a monoclonal antibody (MAb 3H8). This antigen can be extracted in the form of a very high Mr complex, close or over 106 Da, by treatment, with β-1,3-glucanase, β mercaptoethanol or dithothreitol, or mild alkali, but not by saturated hydrogen fluoride (HF) in pyridine, suggesting that the complex is bound to wall β-1,3 glucans, and to proteins by disulfide bonds, but not to β-1,6 glucans. Through its sensitivity to trypsin and different deglycosylation procedures, it was concluded that the epitope is associated to a glycoprotein containing N-glycosidic, but not O-glycosidi…

It is Time for Action in the Struggle against Antibiotic-Resistance, Let’s Start Reducing or Replacing Antibiotics in Agriculture

2016

Million people around the world are infected each year and thousands of them die from pathogens that are resistant to the treatment by any of known antibiotics [1]. The excessive use and abuse of antibiotics in clinical setting and in agriculture, added to the great ability of microorganisms to evolve, are the causes of the wide spread of isolates resistant to all major classes of current antibiotics. It is time for action in order to tackle antimicrobial-resistance (AMR), which can be considered a major threat to global health care and security. While we are waiting for new antimicrobial molecules and strategies, shorter-term approaches are needed to address the menace of AMR and preserve …

Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry ye…

2018

Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. During active dry yeast (ADY) production, antioxidant systems play an essential role in yeast survival and vitality as both biomass propagation and dehydration cause cellular oxidative stress and negatively affect technological performance. Mechanisms for adaptation and resistance to desiccation have been described for S. cerevisiae, but no data are available on the physiology and oxidat…

Structural characterization of polysaccharides of a productive strain of the culinary-medicinal king oyster mushroom, pleurotus eryngii (Agaricomycet…

2018

A preliminary biological investigation of the dry basidiomata of strain C-142-c of Pleurotus eryngii has shown significant antioxidant activity. Two different polysaccharides (PEPS-A1 and PEPS-A2) were isolated from the cultivated edible mushroom, P. eryngii C-142-c strain. Based on acid hydrolysis, methylation analysis, and nuclear magnetic resonance experiments (1H, 13C, distortionless enhancement by polarization transfer, double quantum filtered correlation spectroscopy, total correlation spectroscopy, nuclear Overhauser effect spectroscopy, heteronuclear singlequantum correlation spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structures of the repeating uni…

Anticancer, antioxidant, and antibacterial activities of low molecular weight bioactive subfractions isolated from cultures of wood degrading fungus …

2017

The aim of this study is to investigate in vitro the anticancer, antioxidant, and antibacterial activities of three low molecular weight subfractions I, II and III isolated from secondary metabolites produced by the wood degrading fungus Cerrena unicolor. The present study demonstrated that the low molecular weight subfractions III exhibited the strongest inhibitory activity towards breast carcinoma cells MDA-MB-231, prostatic carcinoma cells PC3, and breast cancer cells MCF7 with the half-maximal inhibitory concentration (IC50) value of 52,25 μg/mL, 60,66 μg/mL, and 54,92 μg/mL, respectively. The highest percentage of inhibition was noted at a concentration of 300 μg/mL in all the examined…