Candida auris Discovery through Community Wastewater Surveillance during Healthcare Outbreak, Nevada, USA, 2022.

Candida auris transmission is steadily increasing across the United States. We report culture-based detection of C. auris in wastewater and the epidemiologic link between isolated strains and southern Nevada, USA, hospitals within the sampled sewershed. Our results illustrate the potential of wastewater surveillance for containing C. auris.

Special yeasts for non- alcoholic and low-alcohol beers

During the coronavirus pandemic, some brewers used free capacities for product development. Novel maltose-negative yeasts from the "Hefejagd" (yeast hunt) project of the Research Center Weihenstephan formed the basis for more yeast biodiversity. This article examined the tried-and-true method of producing non-alcoholic beer with Saccharomyces ludwigii and the yeast strains Cyberlindnera misumaiensis, Cyberlindnera saturnus, and Kluyveromyces marxianus and their properties. The spectrum for producing non-alcoholic beers with maltose-negative yeasts is practically unlimited. The Research Center Weihenstephan included just three novel candidates in its study;they had previously been used very successfully for the production of non-alcoholic beers. This technology is so fascinating because it can be used for the production of non-alcoholic beers as well as non-alcoholic malt-based beverages. Two novel yeasts that are POF positive, i.e., they produce 4-vinylguaiacol, typical of wheat beer, have been added to the program and are thus ideal for brewing non-alcoholic wheat beers. Note should also be taken of the fact that prior to the invention of pure yeast culture by Emil Christian Hansen and Paul Lindner, such "foreign yeasts" had all along contributed to beer flavor and "house flavor" in mixed populations. Lindner and Delbriick initially described the beers as "empty and neutral" following the invention of yeast puree cultures. The time has come to make "yeast accessories" available to brewers in a controlled and scientific manner and to produce a targeted house flavor. This applies to both the non-alcoholic and alcoholic beer sectors.

Determining the effects of some bacteria on wooden toys treated with antibacterial protective coatings

Several protective coatings enhanced by antimicrobial agents and/or pigments were considered for the wooden toy market: water-based matte varnish, an ultra-hygiene water-based matte varnish (WBV-UH), a polyurethane matte varnish (PUV), and an ultra-hygiene antiviral polyurethane matte varnish (PUV-UH), as well as a water-based dye (WBV 5%K), an ultra-hygiene water-based dye (WBV-UH 5%K), a polyurethane dye (PUV 5%K), and an ultra-hygiene polyurethane dye (PUV-UH 5%K), which contain 5% red nano-pigment (K). By utilizing 7 kinds of bacteria and 2 types of yeast that are commonly detected in routine, daily settings, the efficacy of the different protective coatings on wooden toy surface was investigated. The antibacterial and antimicrobial activities of the tested dye samples were based on the agar-well diffusion method. Ultimately, the study found that the addition of antimicrobial agents to several different protective coatings and dyes resulted in the presence of antimicrobial activity vs. the lack thereof with protective coatings and dyes alone. Additionally, some of the dyes with added antimicrobial agents were found to be effective against biofilm formation. Overall, the addition of pigment into the coating, alongside the addition of antimicrobial agents, proved to be highly effective in inhibiting growth and spread of microorganisms on wooden toy surface.

Hospital superbug traced to remote island beach

Anuradha Chowdhary, professor of mycology, Vallabhbhai Patel Chest Institute, University of Delhi, and corresponding author of the study, says that while C. auris isolates found on the beach were multidrug-resistant, those found in the remoter salt marshes of the Andaman islands were not resistant to ordinary anti-fungal drugs. “Thorough screening of patients and their environment is required as also cohorting (putting together) of patients who are colonised by C. auris —since they continuously shed viable yeast cells from their skin and contaminate hospital environments.” The present study notes that a hypothesis published July 2019 in mBiosuggests that C. auris might be native to wetlands and that its emergence as a human pathogen may be linked to the effects of global warming effects on wetlands.

Changes in urban soil yeast communities after a reduction in household waste during the COVID-19 pandemic.

The soils of streets, urban parks and suburban areas were examined for yeasts in the summer of 2020 on the territory of the southern cities of Russia and the Republic of Crimea: Krasnodar, Maykop, Sochi and Simferopol. The results of this study are compared with the results of a previous study carried out in these cities in 2019. This study was conducted three months after the lockdown due to the COVID-19 pandemic, which led to a sustained decline in household waste deposition in these areas. The number of tourists visiting these southern cities decreased significantly, and the number of walkers and visitors to urban parks fell sharply. In 2020, after the decline of household waste loads, the yeast abundance was slightly but reliably higher than in 2019. A total of 30 yeast species were observed - 11 ascomycetes and 19 basidiomycetes. This was more than in 2019 and was caused by twice as many autochthonous basidiomycetous yeast species (natural core community), which were found in urban soils only after the reduction in household waste in the environment - Apiotrichum dulcitum, A. laibachii, Saitozyma podzolica Solicoccozyma terricola. And at the same time, the proportion of clinically significant (opportunistic) yeasts, Candida sake and Meyerozyma guilliermondii, was much lower in 2020 than in 2019. Thus, the observed changes in yeast communities in urban soils could be a short-time response of the microbial community to a reduction in household waste.

Antimicrobial Activity of Aspergillus sp. from the Amazon Biome: Isolation of Kojic Acid

The antimicrobial potential of Aspergillus sp., isolated from the Amazon biome, which is stored at the Amazon Fungi Collection-CFAM at ILMD/FIOCRUZ, was evaluated. The fungal culture was cultivated in yeast extract agar and sucrose (YES) for cold extraction of the biocompounds in ethyl acetate at 28 °C for 7 days in a BOD type incubator. The obtained extract was evaluated for its antimicrobial activity against Candida albicans and Gram-positive and negative bacteria by the “cup plate” method and the determination of the minimum inhibitory concentration (MIC) by the broth microdilution method. The extract was subjected to thin layer chromatography (TLC) and fractionated by open and semipreparative column chromatography. The fractions of interest had their chemical constituents elucidated by nuclear magnetic resonance and mass spectrometry. The elucidated molecule was evaluated for cytotoxicity against the human fibroblast strain (MRC5). The extract presented inhibitory activity against both Gram-positive and negative bacteria, with the range of inhibition halos from 5.3 to 14 mm in diameter and an MIC ranging from 500 to 15.6 μg/mL. Seventy-one fractions were collected and TLC analysis suggested the presence of substances with double bond groups: coumarins, flavonoids, phenolic, alkaloids, and terpenes. NMR and MS analyses demonstrated that the isolated molecule was kojic acid. The results of the cytotoxicity test showed that MRC5 cells presented viability at concentrations from 500 to 7.81 μg/mL. The kojic acid molecule of Aspergillus sp., with antibacterial activity and moderate toxicity at the concentrations tested, is a promising prototype of an alternative active principle of an antimicrobial drug.

An overview of COVID-19 related to fungal infections: what do we know after the first year of pandemic?

In 2019, severe acute respiratory syndrome caused by CoV-2 virus became a pandemic worldwide, being the fast spread of the disease due to the movement of infected people from one country to another, from one continent to another, or within the same country. Associated comorbidities are important factors that predispose to any fungal coinfections. Because of the importance of fungal infections in COVID-19 patients, the aim of this work was to collect data of the more encountered mycoses related to patients undergoing this disease. Aspergillosis was the first COVID-19-related fungal infection reported, being A. fumigatus the most frequent species for CAPA. Other fungal infections related include mainly candidiasis and mucormycosis, being Rhizopus spp. the more prevalent species found. Influenza-associated pulmonary aspergillosis is well documented; thus, similar complications are expected in severe forms of COVID-19 pneumonia. Therefore, in patients with COVID-19, it is important to take special attention to the surveillance and suspicion of fungal coinfections that might worsen the patient's prognosis.

From Sharks to Yeasts: Squalene in the Development of Vaccine Adjuvants.

Squalene is a natural linear triterpene that can be found in high amounts in certain fish liver oils, especially from deep-sea sharks, and to a lesser extent in a wide variety of vegeTable oils. It is currently used for numerous vaccine and drug delivery emulsions due to its stability-enhancing properties and biocompatibility. Squalene-based vaccine adjuvants, such as MF59 (Novartis), AS03 (GlaxoSmithKline Biologicals), or AF03 (Sanofi) are included in seasonal vaccines against influenza viruses and are presently being considered for inclusion in several vaccines against SARS-CoV-2 and future pandemic threats. However, harvesting sharks for this purpose raises serious ecological concerns that the exceptional demand of the pandemic has exacerbated. In this line, the use of plants to obtain phytosqualene has been seen as a more sustainable alternative, yet the lower yields and the need for huge investments in infrastructures and equipment makes this solution economically ineffective. More recently, the enormous advances in the field of synthetic biology provided innovative approaches to make squalene production more sustainable, flexible, and cheaper by using genetically modified microbes to produce pharmaceutical-grade squalene. Here, we review the biological mechanisms by which squalene-based vaccine adjuvants boost the immune response, and further compare the existing sources of squalene and their environmental impact. We propose that genetically engineered microbes are a sustainable alternative to produce squalene at industrial scale, which are likely to become the sole source of pharmaceutical-grade squalene in the foreseeable future.

Effect of signal molecules for enhanced production of boeravinone B in shoot cultures of Boerhaavia diffusa (L.)

High performance thin layer chromatography (HPTLC) analysis was used to analyze boeravinone B production in shoot cultures of Boerhaavia diffusa under the influence of different biotic [yeast extract (YE), cellulase (CL)] and abiotic [salicylic acid (SA), jasmonic acid (JA)] signal molecules at different concentrations. Biomass accumulation and boeravinone B production in shoot cultures raised on agar solidified medium were analysed for a period of 30 days to optimize the suitable age of culture for treatment with signal molecules. A maximum yield of boeravinone B (5.74 %) was obtained after 7 days and therefore treatments were performed at a gap of 3, 6 and 9 days. Signal molecules used at varied concentrations differentially influenced the shoot cultures for biomass regeneration and culture growth. Cellulase treatment (0.5 mgl-1) resulted in maximizing biomass (1.30gm) and boeravinone B content (22.7 %) after 6 days of exposure time as compared to other treatments used in the study. Thus the current study can be exploited further for enhancement of boeravinone B from shoot cultures of Boerhaavia diffusa.

The Flo Adhesin Family.

The first step in the infection of fungal pathogens in humans is the adhesion of the pathogen to host tissue cells or abiotic surfaces such as catheters and implants. One of the main players involved in this are the expressed cell wall adhesins. Here, we review the Flo adhesin family and their involvement in the adhesion of these yeasts during human infections. Firstly, we redefined the Flo adhesin family based on the domain architectures that are present in the Flo adhesins and their functions, and set up a new classification of Flo adhesins. Next, the structure, function, and adhesion mechanisms of the Flo adhesins whose structure has been solved are discussed in detail. Finally, we identified from Pfam database datamining yeasts that could express Flo adhesins and are encountered in human infections and their adhesin architectures. These yeasts are discussed in relation to their adhesion characteristics and involvement in infections.

Hydrocarbon-Contaminated Sites: Is There Something More Than Exophiala xenobiotica? New Insights into Black Fungal Diversity Using the Long Cold Incubation Method.

Human-made hydrocarbon-rich environments are important reservoirs of microorganisms with specific degrading abilities and pathogenic potential. In particular, black fungi are of great interest, but their presence in the environment is frequently underestimated because they are difficult to isolate. In the frame of a biodiversity study from fuel-contaminated sites involving 30 diesel car tanks and 112 fuel pump dispensers (52 diesel and 60 gasoline, respectively), a total of 181 black fungal strains were isolated. The long cold incubation (LCI) of water-suspended samples, followed by plating on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), gave isolation yields up to six times (6.6) higher than those of direct plating on DRBC, and those of enrichment with a phenolic mix. The sequencing of ITS and LSU-rDNA confirmed the dominance of potentially pathogenic fungi from the family Herpotrichiellaceae and Exophiala xenobiotica. Moreover, other opportunistic species were found, including E. opportunistica, E. oligosperma, E. phaeomuriformis, and Rhinocladiella similis. The recurrent presence of E. crusticola, Knufia epidermidis, Aureobasidium melanogenum, Cladosporium spp., and Scolecobasidium spp. was also recorded. Interestingly, 12% of total isolates, corresponding to 50% of taxa found (16/32), represent new species. All the novel taxa in this study were isolated by LCI. These findings suggest that black fungal diversity in hydrocarbon-rich niches remains largely unexplored and that LCI can be an efficient tool for further investigations.