Synthesis and antibacterial activity of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a] azepin-1-ium bromides and aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines

The aim of this work is to develop methods of synthesis of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides and aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines and to study their antimicrobial activity against strains of gram-positive and gram-negative bacteria as well as yeast fungi. Materials and methods. 1Н NMR spectra were recorded on Bruker 400 spectrometer operating at frequency of 400 MHz. Antimicrobial activity of the compounds synthesized was evaluated by their minimum inhibitory concentration (MIC) values. Results and discussion. The interaction of 3-arylaminomethyl-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepines with substituted phenacyl bromides produced novel 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides. The latter when refluxed in 10 % solution of NaOH gave aryl-(4-R1-phenyl-5,6,7,8-tetrahydro-2,2a,8a-triazacyclopenta[cd]azulen-1-ylmethyl)-amines. The study of antimicrobial activity of the compounds obtained allowed to find derivatives which are active against С. albicans and S. aureus strains. Among the compounds tested 3-[(41-bromophenylamino)-methyl]-1-[2-(4-methoxyphenyl)-2-oxoethyl]-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromide 5cd appeared to be more active than the reference drug Cefixime and displayed close antimicrobial activity as the antibiotic Linezolid. Conclusions. It was found out that derivatives of 3-arylaminomethyl-1-(2-oxo-2-arylethyl)-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-1-ium bromides display broad spectrum of antimicrobial activity and are able to inhibit growth of both bacteria and fungi. S. aureus and C. albicans turned out to be the most sensitive strains to the compounds tested, MIC was in the range of 6.2-25.0 mg/mL. Gram-negative strains of microorganisms were less sensitive to the compounds evaluated and 5fа was the most active derivative displaying antimicrobial activity at the concentration of 50.0 mg/mL. Antimicrobial activity of triazoloazepinium bromide derivatives was similar to that one of Linezolid and Fluconazole reference drugs and more pronounced than the activity of Cefixime. Hence, the data gathered evidence the feasibility of further study of the antimicrobial properties of the most active compounds in in vivo experiments aiming at assessment of the prospects for the creation of new effective and safe antimicrobial drugs based on them

Microbiological landscape of the periodontal pocket in inflammatory diseases in the periodontal tissues

Relevance. The study of the microbiological composition of periodontal pockets in inflammatory diseases of periodontal tissues is of great importance directly for the effective treatment and understanding of the pathogenetic stages of these diseases. Objective: to study the microbiological landscape of periodontal pockets with inflammatory diseases of periodontal tissues. Materials and Methods. 62 patients aged 20 to 45 years were selected and divided into groups depending on the form of periodontitis: with localized aggressive periodontitis - group №1, group №2 - with chronic generalized periodontitis, group № 3 - with exacerbation of chronic generalized periodontitis. The material for the study was taken from the periodontal pockets and examined by cultural and microbiological methods. Results and Discussion. It was found that the proportion and number of microbial associations in the periodontal pockets of different depths differs. In localized aggressive periodontitis, mainly facultative Gr+ (A. actinomycetemcomitans) and Gr- (St. aureus, Str. mitis) anaerobes were found in the periodontal pockets no more than 4 mm. In generalized chronic periodontitis of moderate degree, the same microorganisms were present in the periodontal pockets as in the localized form, but Str. mitis was more common among facultative aerobes. With the exacerbation of generalized chronic periodontitis from facultative anaerobes, St. aureus was more common and the proportion and number of A. actinomycetemcomitans significantly increased. Conclusion. According to the results of the study, the microorganisms that inhabit the periodontal pockets in inflammatory diseases of periodontal tissues mainly belong to facultative Gr+ and Gr - anaerobes, obligate Gr+ and Gr-anaerobes and yeast fungi.

Deciphering the potential niche of novel black yeast fungal isolates in a biological soil crust based on genomes, phenotyping, and melanin regulation

Black yeasts are polyextremotolerant fungi that contain high amounts of melanin in their cell wall and maintain a primarily yeast form. These fungi grow in xeric, nutrient deplete environments which implies that they require highly flexible metabolisms and the ability to form lichen-like mutualisms with nearby algae and bacteria. However, the exact ecological niche and interactions between these fungi and their surrounding community is not well understood. We have isolated two novel black yeast fungi of the genus Exophiala: JF 03-3F “Goopy” E. viscosium and JF 03-4F “Slimy” E. limosus, which are from dryland biological soil crusts. A combination of whole genome sequencing and various phenotyping experiments have been performed on these isolates to determine their fundamental niches within the biological soil crust consortium. Our results reveal that these Exophiala spp. are capable of utilizing a wide variety of carbon and nitrogen sources potentially from symbiotic microbes, they can withstand many abiotic stresses, and can potentially provide UV resistance to the crust community in the form of secreted melanin. Besides the identification of two novel species within the genus Exophiala, our study also provides new insight into the production and regulation of melanin in extremotolerant fungi.

Soil Disturbance Impact on Crop Ergothioneine Content Connects Soil and Human Health

Ergothioneine (ERGO) is a potent antioxidant and anti-inflammatory amino acid that is produced in nature mainly by non-yeast fungi, cyanobacteria, and mycobacteria. Mounting evidence suggests that ERGO can be considered a longevity vitamin that can mitigate chronic diseases of aging and thereby increase life expectancy. Humans must obtain ERGO from their diet, and it is therefore important to know which foods contain it. Although ERGO is not produced by plants it is found in plant products such as grain, apparently because detrital or symbiotic soil fungi pass on ERGO to plants through their roots. Besides differences between plant species in their ability to accumulate ERGO, how they are managed might also affect its concentration. Soil tillage has been shown to reduce soil fungal biomass, and therefore ERGO contents in maize, soybeans, and oats grown in soil managed with annual moldboard plowing (most intensive), chisel/disking (less intensive), or no-tillage (least intensive) in crop rotation were compared. ERGO concentrations declined in all three crops as tillage intensity increased, with reductions from no till to moldboard plow of approximately 30% in all three crops. Because crop yield was also negatively impacted by intensive tillage, ERGO yield per hectare was reduced even more due to increasing tillage intensity. This study is one of the first to show that soil health improving practices that minimize soil disturbance can directly enhance a key dietary factor associated with long-term human health.

Systemic antimycotic therapy of patients with mycosis of the oral mucosa and periodontal Сandida etiology

Candidiasis is the most common mycosis. Оral candidiasis occurs in the form of stomatitis, including the so-called prosthetic stomatitis. Somewhat less often, fungi of the genus Candida are detected with gingivitis and periodontitis, manifestations of red lichen planus on the oral mucosa.The purpose of the work: to analyze the results of mycological studies and determine the sensitivity of fungi isolated from the oral cavity in vari-ous oral pathologies to the main antimycotics, as well as the formation on this basis of an algorithm for antimycotic therapy of candidal lesions of the oral mucosa and periodontium.Material and methods. The paper uses the results of studies of patients with candidiasis of the oral mucosa (127 patients), prosthetic stomatitis (136 patients), candida-associated periodontitis (168 patients). Primary inoculation was performed quantitatively on Sabouraud’s medium and duplicated on M1297 chromogenic medium (Himedia Labs, India).To study the biofilm formed on the oral mucosa, fixed preparations of gold-coated scrapings were prepared for scanning electron microscopy, which was performed using a Quanta 200 3D bi-beam microscope (USA). Sensitivity to antimycotics was assessed using the traditional method of disks.The results of the study. When studying the species composition of yeast-like fungi isolated from the material, it was found that the species C. albicans was isolated in 80% of patients, in association with other species: C. Krusei, C. guilliermondii and C. glabrata. The second place was taken by the species C. Krusei, which was detected in 13.3% of patients. Representatives of this genus of yeast fungi are characterized by the formation of a biofilm with a pronounced mantle, which protects the microorganism from aggressive factors, including antimycotics and antiseptics. All the studied preparations showed fungicidal activity against these strains of yeast-like fungi. When registering the results, it was found that the most pronounced sensitivity of yeast-like fungi of this species was to drugs from the group of azole derivatives. The most pronounced antifungal activity was noted by us in voriconazole.Conclusion. Based on the obtained data, an algorithm of systemic antimycotic therapy for oral candidiasis has been developed.

Single Cell Protein: A Potential Substitute in Human and Animal Nutrition

Single cell protein (SCP) is the first product of the fermentation process and has proven to be a good protein alternative. Food competition is becoming more intense as the world’s population continues to grow. Soon, SCP may be able to compensate for a protein deficit. Various global businesses are focusing on SCP production, and the scope of its application is expanding as time and knowledge increases. High quantities of SCP can be produced by microorganisms, such as algae, yeast, fungi and bacteria, due to their fast development rate and the significant level of protein in their chemical structure. Beside proteins, SCP contains carbohydrates, nucleic acids, lipids, minerals, vitamins and several important amino acids. SCP has been an effective substitute for more expensive protein sources such as fish and soybean products. In conclusion, SCP can easily replace traditional protein sources in human and animal feed without detrimental effects. Potential substrate candidates and optimization strategies for SCP production have been extensively studied. This review article focuses on the various aspects of SCP, from its production, using different substrates, player microorganisms and nutritional benefits, to its economic aspects.

Loss of Septation Initiation Network (SIN) kinases blocks tissue invasion and unlocks echinocandin cidal activity against Aspergillus fumigatus

Although considered effective treatment for many yeast fungi, the therapeutic efficacy of the echinocandin class of antifungals for invasive aspergillosis (IA) is limited. Recent studies suggest intense kinase- and phosphatase-mediated echinocandin adaptation in A. fumigatus. To identify A. fumigatus protein kinases required for survival under echinocandin stress, we employed CRISPR/Cas9-mediated gene targeting to generate a protein kinase disruption mutant library in a wild type genetic background. Cell wall and echinocandin stress screening of the 118 disruption mutants comprising the library identified only five protein kinase disruption mutants displaying greater than 4-fold decreased echinocandin minimum effective concentrations (MEC) compared to the parental strain. Two of these mutated genes, the previously uncharacterized A. fumigatus sepL and sidB genes, were predicted to encode protein kinases functioning as core components of the Septation Initiation Network (SIN), a tripartite kinase cascade that is necessary for septation in fungi. As the A. fumigatus SIN is completely uncharacterized, we sought to explore these network components as effectors of echinocandin stress survival. Our data show that mutation of any single SIN kinase gene caused complete loss of hyphal septation and increased susceptibility to cell wall stress, as well as widespread hyphal damage and loss of viability in response to echinocandin stress. Strikingly, mutation of each SIN kinase gene also resulted in a profound loss of virulence characterized by lack of tissue invasive growth. Through the deletion of multiple novel regulators of hyphal septation, we show that the non-invasive growth phenotype is not SIN-kinase dependent, but likely due to hyphal septation deficiency. Finally, we also find that echinocandin therapy is highly effective at eliminating residual tissue burden in mice infected with an aseptate strain of A. fumigatus. Together, our findings suggest that inhibitors of septation could enhance echinocandin-mediated killing while simultaneously limiting the invasive potential of A. fumigatus hyphae.