One of the most important questions in microbiology nowadays, is how apparently harmless, commensal yeasts like Candida spp. can cause a rising number of infections. The occurrence of the disease requires firstly the attachment to the host cells, followed by the invasion of the tissue. The adaptability translates into a rapid ability to respond to stress factors, to take up nutrients or to multiply under different conditions. By forming complex intracellular networks such as biofilms, Candida spp. become not only more refractive to antifungal therapies but also more prone to cause disease. The inter-microbial interactions can enhance the virulence of a strain. In vivo, the fungal cells face a multitude of challenges and, as a result, they develop complex strategies serving one ultimate goal: survival. This review presents the virulence factors of the most important Candida spp., contributing to a better understanding of the onset of candidiasis and raising awareness of the highly complex interspecies interactions that can change the outcome of the disease.

Biosynthesized silver nanoparticles (AgNPs) are widely used in Pharmacy and Medicine. In particular, AgNPs synthesized and mediated by plant extracts have shown topossess several biological activities. In the present study, AgNPs were synthesized using Picea abies L. stem bark extract as reducing agent. Factors, such as metal ion solution, pH, and time, which play a role in the AgNPs synthesis, were assessed. The synthesized AgNPs were characterized by Ultraviolet-Visible Spectrometry, Fourier transform infrared spectroscopy, and Transmission Electron Microscopy (TEM). Further, the study has been extended to evaluate the antimicrobial and antioxidant activity of AgNPs. The broad peak obtained at 411–475 nm (UV-Vis spectroscopy), and the color change pattern, confirmed the synthesis of AgNPs. TEM results showed spherical or rarely polygonal AgNPs with an average size of 44 nm at pH = 9. The AgNPs showed antioxidant activity and antibacterial effect against human pathogenic Gram-positive and Gram-negative bacteria. The results show that spruce bark extract is suitable for obtaining AgNPs, with antibacterial and antioxidant activity.

Diarrheal disease is still a major public health concern, as it is still considered an important cause of death in children under five years of age. A few decades ago, the detection of enteropathogenic E. coli was made by detecting the O, H, and K antigens, mostly by agglutination. The recent protocols recommend the molecular methods for diagnosing EPEC, as they can distinguish between typical and atypical EPEC by identifying the presence/absence of specific virulence factors. EPEC are defined as diarrheagenic strains of E. coli that can produce attaching and effacing lesions on the intestinal epithelium while being incapable of producing Shiga toxins and heat-labile or heat-stable enterotoxins. The ability of these strains to produce attaching and effacing lesions enable them to cause localized lesions by attaching tightly to the surface of the intestinal epithelial cells, disrupting the surfaces of the cells, thus leading to the effacement of the microvilli. EPEC are classified on typical and atypical isolates, based on the presence or absence of E. coli adherence factor plasmids. All the EPEC strains are eae positive; typical EPEC strains are eae+, bfpA+, while atypical strains are eae+, bfpA−. No vaccines are currently available to prevent EPEC infections.

The study provides information about separation and identification of natural bioactive compounds from beech (Fagus sylvatica L.) bark with potential therapeutic applications such as antibacterial activity against human pathogens. Beech is a common material used in the wood industry, but its bark is separated from the wood and is considered a by-product. In this study, natural compounds with biological activity were obtained from beech bark by hot water extraction. The high-performance liquid chromatography (HPLC) was used to analyze the phenolic compounds in the beech bark extracts. Spectrophotometric methods were employed for the determination of total phenolic content. Microdilution technique was used for testing the antimicrobial activity of the extract. The following strains were tested: Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa. The yield of extracted polyphenols was of 22.952 mg gallic acid/g dry bark. The compounds identified by HPLC were vanilic acid, catechin, taxifolin and syringin. The extracts were active against Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus. The effect of polyphenolic extract on Gram-negative bacteria was absent at a concentration of 30 mg/mL beach bark extract. Altogether, the use of pure water for extraction of polyphenols from beech bark proved to be an effective eco-friendly method. This method sustains the concept of "green" chemistry by involving the use of renewable plant resources and also by using water as solvent.

BACKGROUND The link between Candida albicans and diabetes mellitus is well-acknowledged, but incompletely elucidated.OBJECTIVES The purpose of this study is to assess the growth rate of C. albicans (CA) in the presence of different concentrations of glucose and fructose, two of the main pathophysiologic and nutritionally relevant sugars in diabetic patients, in order to obtain a better understanding of the nutrient acquisition strategy and its possible relation to the hyperglycemic status of diabetic patients.METHODS The effects of different concentrations of glucose and fructose (1000 mg%, 500 mg%, 250 mg% and 100 mg% w/v) on the growth rate of CA have been studied by flow-cytometry.FINDINGS We found that glucose concentration is directly related to CA growth, which may be linked to the frequent yeast infections that occur in non-controlled diabetic patients; we also show that fructose inhibits CA growth rate.MAIN CONCLUSIONS As a consequence of our hypothesis, the study demonstrates that fructose-containing food may prevent the development of candidiasis, at least in oral sites.

Green synthesis is one of the rapid and best ways for silver nanoparticles (AgNP) synthesis. In the present study, synthesis and bioactivity of AgNPs has been demonstrated using water beech (Fagus sylvatica L.) bark extract. The physical and chemical factors such as time, metal ion solution, and pH, which play a vital role in the AgNPs synthesis, were assessed. The AgNPs were characterized by ultraviolet-visible (UV-Vis) spectrometry, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). Antioxidant and antimicrobial activity of the obtained AgNPs was evaluated. AgNPs were characterized by color change pattern, and the broad peak obtained at 420–475 nm with UV-Vis confirmed the synthesis of AgNPs. FT-IR results confirmed that phenols and proteins of beech bark extract are mainly responsible for capping and stabilization of synthesized AgNPs. TEM micrographs showed spherical or rarely polygonal and triangular particles with an average size of 32 nm at pH = 9, and 62 nm at pH = 4. Furthermore, synthesized AgNPs were found to exhibit antioxidant activity and have antibacterial effect against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Pseudomonas aeruginosa. These results indicate that bark extract of F. sylvatica L. is suitable for synthesizing stable AgNPs, which act as an excellent antimicrobial agent.

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Spruce is a used material in the wood industry and bark is regarded as a by-product. The aim of this study was to provide information about natural bioactive compounds from spruce (Picea abies L.) bark with potential therapeutic applications such as antibacterial activity against human pathogens. Spruce bark extract was obtained by the conventional aqueous extraction (EAM), and second with ultrasounds (USM). It was determined the total polyphenols by spectrophotometric methods and individual polyphenols by high-performance liquid chromatography (HPLC). For the determination of minimum inhibitory concentration was used microdilution technique. The following strains were tested: Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The yield of extracted polyphenols in the case of spruce bark extract was of 33.8mg gallic acid/gfor EAM and 28.73 mg gallic acid/g for USM. The compounds identified in samples, by HPLC, were vanillic acid and taxifolin.It was found that both extracts have antibacterial capacity for all bacteria tested. The antibacterial effect of both extracts was stronger against Gram positive cocci compared with Gram negative bacilli.Antimicrobial spectra and activities of the fractions and pure isolated compounds from the spruce bark, can be suggested the use of spruce bark in pharmaceutical preparations and as well as a food preservative.