Leonurus cardiaca L. herb - a derived extract and an ursolic acid as the factors affecting the adhesion capacity of Staphylococcus aureus in the context of infective endocarditis

The objective was an assessment of the impact of Leonurus cardiaca L. extract (LCE) and ursolic acid (UA) on the adhesive properties of Staphylococus aureus NCTC 8325 strain, expressing virulence factors important in the pathogenesis of infective endocarditis. The adhesion and biofilm formation of bacteria cultured in the presence of subinhibitory concentrations of LCE or UA on the abiotic surface or covered with fibrinogen, fibronectin or collagen, were evaluated. Inhibitory effects of LCE and UA on staphylococcal adherence to both types of surface were demonstrated. This, in the case of UA, resulted in a significant reduction of biofilm formation

Biogenic nanosilver synthesized in Metarhizium robertsii waste mycelium extract - As a modulator of Candida albicans morphogenesis, membrane lipidome and biofilm.

Due to low efficacy of classic antimicrobial drugs, finding new active preparations attracts much attention. In this study an innovative, cost-effective and environmentally friendly method was applied to produce silver nanoparticles (AgNPs) using filamentous fungi Metarhizium robertsii biomass waste. It was shown that these NPs possess prominent antifungal effects against C. albicans, C. glabrata and C. parapsilosis reference strains. Further detailed studies were performed on C. albicans ATCC 90028. AgNPs kill curve (CFU method and esterase-mediated reduction of fluorescein diacetate); fractionally inhibitory concentration index (FICI) with fluconazole (FLC); effect on fungal cell membrane permeability (propidium iodide (PI) staining), membrane lipids profile (HPLC-MS), yeast morphotypes and intracellular reactive oxygen species level (H2DCFDA probe) were investigated. Anti-adhesive and anti-biofilm properties of AgNPs (alone and in combination with FLC) were also tested. Biosafety of AgNPs use was assessed in vitro in cytotoxicity tests against L929 fibroblasts, pulmonary epithelial A549 cell line, and red blood cells. Significant reduction in the viability of yeast cells treated with AgNPs was shown within 6 h. The proportion of C. albicans PI-positive cells increased in a dose and time-dependent manner. Changes in the qualitative and quantitative profile of cell membrane lipids, including significant decline in the quantity of most phospholipid species containing C18:2 and an increase in the amount of phospholipids containing C18:1 acyl species were observed after yeast exposure to AgNPs. CLSM images showed an enhancement in ROS intracellular accumulation in C. albicans treated with biogenic nanosilver. C. albicans transformation from yeast to hyphal forms was also reduced. AgNPs decreased adhesion of yeast to abiotic surfaces, as well as acted synergistically with FLC against sessile population. At fungicidal and fungistatic concentrations, they were non-toxic to mammalian cells. Obtained results confirm suitability of our "green synthesis" method to produce AgNPs with therapeutic potential against fungal infections

Level of mannose-biding lectin (MBL) in patients with tuberculosis

Mannose-binding lectin (MBL) constitutes an important element in innate immune response against invading microorganisms. On the other hand, it has also been suggested that MBL, due their opsonic activity, might facilitate the uptake of certain intracellular pathogens. The aim of this study was to investigate whether MBL plays a role in tuberculosis. MBL serum concentration was determined in 68 patients with tuberculosis (TB), 30 patients with non-TB lung diseases and in 64 healthy controls. Serum MBL level was tested by an ELISA test with S. cerevisiae mannan -coated microtiter plates. Generaly, TB patients had significantly higher MBL levels than both control groups, and in TB group percentage of individuals with highest MBL level was significantlyhigher(39.7%).Theseresults indicate that high levels of MBL may be involved in the pathogenesis of tuberculosis and to be a relative disadvantage in mycobacterial infection

IgG anti-multiantigen sonicate of mycobacterium tuberculosis (Mts) measured by ELISA-Mts

Laboratory diagnosis of tuberculosis (TB) is often difficult. In recent years the detection of TB bys erologic means has been the subject of a number of investigations.We studied the diagnostic utility of enzyme-linked immunosorbent assay in pulmonary tuberculosis. Two serological tests, commercial Pathozyme-Myco IgG (Omega Diagn.), and self-prepared ELISA-Mts using mycobacteria sonicate were evaluated simultaneously with 132 serum samples. Frequency and level of anti-mycobacterial IgG were compared in sera from 68 patients with TB and in sera from 64 healthy volunteers. The sensitivities of the tests with sera from TB patients were, respectively 55.9% and 70.6%. The specificities of these tests were respectively 98.5%and 84.4%. By combining two tests, a maximum sensitivity of 76.5% was obtained with reciprocal drops in specificity to 82.8%. Despite of that, it has been suggested that combinations of different antigens were attempted in order to improve the diagnostic yield

Time and concentration-dependent effect of AgNPs on <i>C</i>. <i>albicans</i> ATCC 90028 growth.

<p>The results are the mean (% of yeast survival ± S.D.) from 2 independent experiments done in quadruplicate as described in Materials and Methods.</p

Staphylococcus aureus&mdash;A Known Opponent against Host Defense Mechanisms and Vaccine Development&mdash;Do We Still Have a Chance to Win?

The main purpose of this review is to present justification for the urgent need to implement specific prophylaxis of invasive Staphylococcus aureus infections. We emphasize the difficulties in achieving this goal due to numerous S. aureus virulence factors important for the process of infection and the remarkable ability of these bacteria to avoid host defense mechanisms. We precede these considerations with a brief overview of the global necessitiy to intensify the use of vaccines against other pathogens as well, particularly in light of an impasse in antibiotic therapy. Finally, we point out global trends in research into modern technologies used in the field of molecular microbiology to develop new vaccines. We focus on the vaccines designed to fight the infections caused by S. aureus, which are often resistant to the majority of available therapeutic options

Percentage composition of cell membrane phospholipid classes (Pls) of control <i>C</i>. <i>albicans</i> ATCC 90028 (C) or cells treated with AgNP at MIC or 0.5× MIC for 2 and 24 h (measured by HPLC-MS).

<p>PA—phosphatidic acid, PC—phosphatidylcholine, PE—phosphatidylethanolamine, PG—phosphatidylglycerol, PI—phosphatidylinositol, PS—phosphatidylserine, CL—cardiolipin.</p

Mycelium of <i>C</i>. <i>albicans</i> ATCC 90028 formation after 24 h exposure to AgNPs at MIC or 0.5× MIC.

<p><i>C</i>. <i>albicans</i> mycelium stained with Calcofluor White was checked microscopically (fluorescence microscope, Zeiss, AXIO Scope A1, magnification 400×); representative images are shown.</p

Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of silver nanoparticles (AgNPs) against <i>Candida</i> sp.

<p>Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of silver nanoparticles (AgNPs) against <i>Candida</i> sp.</p