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Pathogens (Basel, Switzerland) Mar 2024has been previously classified as , , and and was recently reclassified in the genus after phylogenetic analysis of its genetic sequence. An increasing number of... (Review)
Review
has been previously classified as , , and and was recently reclassified in the genus after phylogenetic analysis of its genetic sequence. An increasing number of reports of human infections by have emerged, suggesting that this microorganism is an emerging pathogen. The present review aimed to provide data on the epidemiology, antifungal resistance, clinical characteristics, treatment, and outcomes of fungemia by by extracting all the available information from published original reports in the literature. PubMed/Medline, Cochrane Library, and Scopus databases were searched for eligible articles reporting data on patients with this disease. In total, 36 studies involving 170 patients were included. The age of patients with fungemia by ranged from 0 to 89 years; the mean age was 22.8 years, the median age was 2.2 years, with more than 37 patients being less than one month old, and 54% (88 out of 163 patients) were male. Regarding patients' history, 70.4% had a central venous catheter use (CVC), 28.7% were on total parenteral nutrition (TPN), 97% of neonates were hospitalized in the neonatal ICU (NICU), and 39.4% of the rest of the patients were hospitalized in the intensive care unit (ICU). Previous antimicrobial use was noted in 65.9% of patients. The most common identification method was the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in 34.1%, VITEK and VITEK 2 in 20.6%, and ID32 C in 15.3%. had minimal antifungal resistance to fluconazole, echinocandins, and amphotericin B, the most commonly used antifungals for treatment. Fever and sepsis were the most common clinical presentation noted in 95.8% and 86%, respectively. Overall mortality was 20% and was slightly higher in patients older than one year. Due to the rarity of this disease, future multicenter studies should be performed to adequately characterize patients' characteristics, treatment, and outcomes, which will increase our understanding and allow drawing safer conclusions regarding optimal management.
PubMed: 38535612
DOI: 10.3390/pathogens13030269 -
Heliyon May 2024The growing amount of plastic waste requires new ways of disposal or recycling. Research into the biodegradation of recalcitrant plastic polymers is gathering pace....
The growing amount of plastic waste requires new ways of disposal or recycling. Research into the biodegradation of recalcitrant plastic polymers is gathering pace. Despite some progress, these efforts have not yet led to technologically and economically viable applications. In this study, we show that respirometric screening of environmental fungal isolates in combination with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy can be used to identify new strains with the potential for the degradation of plastic polymers. We screened 146 fungal strains, 71 isolated from car repair shops, an environment rich in long-chain hydrocarbons, and 75 isolated from hypersaline water capable of growing at high concentrations of NaCl. When grown in a minimal medium with no carbon source, some strains produced significantly more CO when a pure plastic polymer was added to the medium, some only at high salinity. A selection of these strains was shown by FTIR and Raman spectroscopy to alter the properties of plastic polymers: sp. EXF-13502 on polyamide, EXF-13500 on polypropylene, sp. EXF-10630 on low-density polyethylene and EXF-6848 on polyethylene terephthalate. Respirometry in combination with specific spectroscopic methods is an efficient method for screening microorganisms capable of at least partial plastic degradation and can be used to expand the repertoire of potential plastic degraders. This is of particular importance as our results also show that individual strains are only active against certain polymers and under certain conditions. Therefore, efficient biodegradation of plastics is likely to depend on a collection of specialized microorganisms rather than a single universal plastic degrader.
PubMed: 38803974
DOI: 10.1016/j.heliyon.2024.e31130 -
BMC Microbiology Aug 2023The ascomycetous heterothallic yeast Wickerhamomyces anomalus (WA) has received considerable attention and has been widely reported in the winemaking industry for its...
BACKGROUND
The ascomycetous heterothallic yeast Wickerhamomyces anomalus (WA) has received considerable attention and has been widely reported in the winemaking industry for its distinctive physiological traits and metabolic attributes. An increased concentration of ethanol during ethanol fermentation, however, causes ethanol stress (ES) on the yeast cells. Trehalose has been implicated in improving survival under various stress conditions in microorganisms. Herein, we determined the effects of trehalose supplementation on the survival, differentially expressed genes (DEGs), cellular morphology, and oxidative stress tolerance of WA in response to ES.
RESULTS
The results indicated that trehalose improved the survival and anomalous surface and ultrastructural morphology of WA. Additionally, trehalose improved redox homeostasis by reducing the levels of reactive oxygen species (ROS) and inducing the activities of antioxidant enzymes. In addition, DEGs affected by the application of trehalose were enriched in these categories including in gene expression, protein synthesis, energy metabolism, and cell cycle pathways. Additionally, trehalose increased the content of intracellular malondialdehyde (MDA) and adenosine triphosphate.
CONCLUSIONS
These results reveal the protective role of trehalose in ES mitigation and strengthen the possible uses of WA in the wine fermentation sector.
Topics: Trehalose; Saccharomycetales; Adenosine Triphosphate; Ethanol
PubMed: 37644381
DOI: 10.1186/s12866-023-02982-y -
Food Microbiology Aug 2023Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize...
Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize their succession in white-brined cheese during a shelf-life of 52 weeks. White-brined cheeses added herbs (WBC1) or sundried tomatoes (WBC2) were produced at a Danish dairy and incubated at 5 °C and 10 °C. An increase in yeast counts was observed for both products within the first 12-14 weeks of incubation and stabilized afterwards varying in a range of 4.19-7.08 log CFU/g. Interestingly, higher incubation temperature, especially in WBC2, led to lower yeast counts, concurrently with higher diversity of yeast species. Observed decrease in yeast counts was, most likely, due to negative interactions between yeast species leading to growth inhibition. In total, 469 yeast isolates from WBC1 and WBC2 were genotypically classified using the (GTG)-rep-PCR technique. Out of them, 132 representative isolates were further identified by sequencing the D1/D2 domain of the 26 S rRNA gene. Predominant yeast species in WBCs were Candida zeylanoides and Debaryomyces hansenii, while Candida parapsilosis, Kazachstania bulderi, Kluyveromyces lactis, Pichia fermentans, Pichia kudriavzevii, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Wickerhamomyces anomalus were found in lower frequency. Heterogeneity of yeast species in WBC2 was generally larger compared to WBC1. This study indicated that, along with contamination levels, taxonomic heterogeneity of yeasts is an important factor influencing yeast cell counts, as well as product quality during storage.
Topics: Cheese; Yeasts; Polymerase Chain Reaction
PubMed: 37098422
DOI: 10.1016/j.fm.2023.104266 -
Foods (Basel, Switzerland) Sep 2023Microbial inoculation in moromi fermentation has a great influence on the physicochemical and flavour properties of soy sauces. This work investigated the effect of...
Microbial inoculation in moromi fermentation has a great influence on the physicochemical and flavour properties of soy sauces. This work investigated the effect of inoculating and on the flavour formation of early-stage moromi (30 days) fermented at a lower temperature (22 °C) by determining their physicochemical and aroma changes. The results showed that single yeast or LAB inoculation increased the production of amino nitrogen, lactic acid and acetic acid, as well as free amino acids and key flavour components. Particularly, the sequential inoculation of and produced more free amino acids and aromatic compounds, and there might be synergistic effects between these two strains. More characteristic soy sauce flavour compounds, such as benzaldehyde, HEMF, guaiacol and methyl maltol were detected in the sequentially inoculated moromi, and this sample showed higher scores in savoury, roasted and caramel intensities. These results confirmed that sequential inoculation of and could be a choice for the future production of moromi with good flavour and quality under a lower temperature.
PubMed: 37761218
DOI: 10.3390/foods12183509 -
Cureus Feb 2024We report the case of an 84-year-old man with a history of IgG4-related sclerosing cholangitis who was diagnosed with advanced esophageal cancer and underwent radiation...
We report the case of an 84-year-old man with a history of IgG4-related sclerosing cholangitis who was diagnosed with advanced esophageal cancer and underwent radiation and chemotherapy. An implantable central venous access port was placed for chemotherapy and total parenteral nutrition. The patient presented with a fever and received antimicrobial therapy for acute cholangitis but remained febrile, and subsequently, yeast was detected in the aerobic bottle of blood culture obtained from the central venous line. The yeast was identified as . Liposomal amphotericin B was administered, and the central line access port was removed. After confirmation of negative blood cultures and 14 days post treatment, he underwent reinsertion of the central line access port. Due to persistent pain at the insertion site, fluconazole was added for an additional 14 days, and the patient was discharged and transferred to another hospital. is a rare fungal infection with other synonyms including , , and . A literature review of 53 case reports of , , , and was conducted, with a total of 211 cases reviewed. Fungemia was reported in 94% of cases, with central venous catheterization, parental feeding, low birth weight, and immunocompromised status identified as major risk factors. The majority of cases were pediatric, particularly neonatal, and there were reports of nosocomial infections causing outbreaks, with some cases involving the eye such as endophthalmitis or keratitis.
PubMed: 38445156
DOI: 10.7759/cureus.53550 -
Foods (Basel, Switzerland) Oct 2023Currently, non- yeasts are the subject of interest, among other things, for their contribution to the aromatic complexity of wines. In this study, the characterisation...
Currently, non- yeasts are the subject of interest, among other things, for their contribution to the aromatic complexity of wines. In this study, the characterisation of non- yeasts was addressed by their isolation during spontaneous fermentations of organic Verdejo grapes, obtaining a total of 484 isolates, of which 11% were identified by molecular techniques as non- yeasts. Fermentative isolates belonging to the species , , , , , and were analysed. Significant differences were found in the yeast populations established at the different fermentation stages. Interestingly, stood up as a widely distributed species in vineyards, vintages, and fermentation stages. Several of the strains studied stood out for their biotechnological potential in the production of Verdejo wine, showing the presence of relevant enzymatic activity for the release of varietal aromas and the technological improvement of the winemaking process. Three enzymatic activities were found in an important number of isolates, β-glucosidase, protease, and β-lyase, implicated in the positive aromatic impact on this style of white wine. In that sense, all the isolates of presented those activities. isolates were highlighted for their significant β-lyase activity. In addition, was outlined because of its potential to achieve an elevated fermenting power, as well as the lack of lag phase. The results obtained highlight the importance of maintaining the microbial diversity that contributes to the production of wines with unique and distinctive characteristics of the production region.
PubMed: 37835297
DOI: 10.3390/foods12193644 -
Frontiers in Bioengineering and... 2024Polyalcohols such as arabitol are among the main targets of biorefineries aiming to upcycle wastes and cheap substrates. In previous works WC 1501 emerged as an...
Polyalcohols such as arabitol are among the main targets of biorefineries aiming to upcycle wastes and cheap substrates. In previous works WC 1501 emerged as an excellent arabitol producer utilizing glycerol. Arabitol production by this strain is not growth associated, therefore, in this study, pre-grown cells were entrapped in calcium alginate beads (AB) and utilized for glycerol transformation to arabitol. Flasks experiments aimed to assess the medium composition (i.e., the concentration of inorganic and organic nitrogen sources and phosphates) and to establish the appropriate carrier-to-medium proportion. In flasks, under the best conditions of ammonium limitation and the carrier:medium ratio of 1:3 (w/v), 82.7 g/L glycerol were consumed in 168 h, yielding 31.2 g/L arabitol, with a conversion of 38% and volumetric productivity of 186 mg/mL/h. The process with immobilized cells was transferred to laboratory scale bioreactors with different configurations: stirred tank (STR), packed bed (PBR), fluidized bed (FBR), and airlift (ALR) bioreactors. The STR experienced oxygen limitation due to the need to maintain low stirring to preserve AB integrity and performed worse than flasks. Limitations in diffusion and mass transfer of oxygen and/or nutrients characterized also the PBR and the FBR and were partially relieved only in ALR, where 89.4 g/L glycerol were consumed in 168 h, yielding 38.1 g/L arabitol, with a conversion of 42% and volumetric productivity of 227 mg/mL/h. When the ALR was supplied with successive pulses of concentrated glycerol to replenish the glycerol as it was being consumed, 117 g/L arabitol were generated in 500 h, consuming a total of 285 g/L glycerol, with a 41% and 234 mg/L/h. The study strongly supports the potential of WC 1501 for efficient glycerol-to-arabitol conversion using immobilized cells. While the yeast shows promise by remaining viable and active for extended periods, further optimization is required, especially regarding mixing and oxygenation. Improving the stability of the immobilization process is also crucial for reusing pre-grown cells in multiple cycles, reducing dead times, biomass production costs, and enhancing the economic feasibility of the process.
PubMed: 38659644
DOI: 10.3389/fbioe.2024.1375937 -
Foods (Basel, Switzerland) Jul 2023Yeast and lactic acid bacteria (LAB) are known to play an important role in the fermentation process of coffee post-harvest. This study aimed to isolate and screen yeast...
Yeast and lactic acid bacteria (LAB) are known to play an important role in the fermentation process of coffee post-harvest. This study aimed to isolate and screen yeast and LAB to be applied in lab-scale refermentation of commercial green coffee beans and coffee pulp with the aim of modifying the composition of organic acids (OAs) in coffee beans. Yeast and LAB strains were isolated from green coffee beans and dry coffee pulp and identified, and their effect on OA concentration in the coffee beans was quantified. In addition, the effects of different fermentation conditions (additional carbon source, different inoculum dose, and different types of coffee pulp) were evaluated based on OA quantification. Nine yeast isolates of and were identified, and 11 LAB isolates of the species were identified. Of the 7 OAs quantified, quinic acid was the most abundant. The inoculation of isolated yeasts and LAB led to higher concentrations of OAs, showing the potential to realize modification of the OA composition of green coffee beans by re-fermentation with coffee-originated isolates.
PubMed: 37444360
DOI: 10.3390/foods12132622 -
Foods (Basel, Switzerland) Aug 2023In this study, 21 strains of aroma-producing yeast were isolated from Sichuan paocai juice of farmers in western, eastern and southern Sichuan. One strain, Y3, with the...
In this study, 21 strains of aroma-producing yeast were isolated from Sichuan paocai juice of farmers in western, eastern and southern Sichuan. One strain, Y3, with the best aroma-producing characteristics, was screened using an olfactory method and a total ester titration method, and was identified as . The total ester content of Y3 fermentation broth was as high as 1.22 g/L, and there was no white colonies or film on the surface. Meanwhile, the Y3 strain could tolerate 14% salt concentration conditions and grow well in a pH range of 3-4. Through sensory analysis, the fermented mustard with a ratio of to Y3 of 1:1 showed the highest overall acceptability. Ethyl acetate with its fruit and wine flavor was also detected in the fermented Sichuan paocai juice with a mixed bacteria ratio of 1:1, analyzed with SPME-GC-MS technology, as well as phenylethyl alcohol, isobutyl alcohol, isothiocyanate eaters, myrcene and dimethyl disulfide. These contributed greatly to the unique flavor of Sichuan paocai. In general, Y3 enhanced the aroma of the fermented Sichuan paocai.
PubMed: 37569203
DOI: 10.3390/foods12152934