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International Journal of Systematic and... Oct 2019Ethanol production at high temperatures has garnered much interest in recent years and a key factor is the availability of thermotolerant yeasts. During an investigation...
Ethanol production at high temperatures has garnered much interest in recent years and a key factor is the availability of thermotolerant yeasts. During an investigation on the diversity of thermotolerant yeasts from different habitats, a novel yeast species from the spent wash of a distillery unit associated with a sugar factory was isolated. Phylogenetic analysis of D1/D2 large subunit and ITS rRNA genes placed this species in the ascomycetous genus . The novel species can be distinguished from the closely related species using these rRNA gene regions. The cells of the new species are ovoid to ellipsoid with a diameter of 3.5-6.0×2.4-3.10 µm, while cells are cylindrical with a cell diameter of 1.5-3.0×6-23 µm. This novel species represents, together with , one of the two most thermotolerant yeast species in the genus , able to grow at 42 °C sp. nov. is proposed during this study.
Topics: DNA, Fungal; Ethanol; India; Mycological Typing Techniques; Phylogeny; Saccharomycetales; Sequence Analysis, DNA; Wastewater
PubMed: 31343399
DOI: 10.1099/ijsem.0.003616 -
Journal of Infection and Chemotherapy :... Feb 2024The fungus Wickerhamiella pararugosa (Candida pararugosa) has been detected in various human organs but has rarely caused bloodstream infections. This report presents a...
The fungus Wickerhamiella pararugosa (Candida pararugosa) has been detected in various human organs but has rarely caused bloodstream infections. This report presents a case of central venous catheter-related bloodstream infection (CRBSI) of W. pararugosa in an adult. A female patient in her 80s was admitted to our facility for intestinal obstruction caused by colorectal cancer. The patient's ability to consume food was hindered, necessitating the insertion of a central venous catheter (CVC) into the internal jugular vein. On day 3 after admission, the patient developed a fever, prompting blood and CVC tip cultures to be performed. On day 5, yeast-like fungi were discovered in the blood cultures, and fosfluconazole (fluconazole [FLCZ] pro-drug) treatment was initiated. On day 8, yeast-like fungi were identified in both the blood and CVC tip cultures, leading to a diagnosis of CRBSI. The fungus was identified as W. pararugosa through biochemical and genetic characterization. This finding justified the use of micafungin (MCFG) for combination therapy. On day 17, the minimum inhibitory concentrations (MIC) for FLCZ and MCFG were 4-8 and 0.06 μg/mL, respectively. Accordingly, the treatment was changed to monotherapy with MCFG. After a 21-day treatment regimen, the patient was discharged on day 31. We present a case of CRBSI caused by W. pararugosa in an adult with intestinal obstruction. The notable increase in the MIC of FLCZ necessitated monotherapy with MCFG, which resulted in successful recovery of the patient.
PubMed: 38369124
DOI: 10.1016/j.jiac.2024.02.014 -
Canadian Journal of Ophthalmology.... Aug 2021
Topics: Antifungal Agents; Eye Infections, Fungal; Humans; Keratitis; Saccharomycetales; Voriconazole
PubMed: 33745876
DOI: 10.1016/j.jcjo.2021.02.023 -
Brazilian Journal of Microbiology :... Jun 2023Infections caused by uncommon Candida species have dramatically increased in recent decades, mostly among hematological malignancies. This report aims to present a case...
Infections caused by uncommon Candida species have dramatically increased in recent decades, mostly among hematological malignancies. This report aims to present a case of Candida pararugosa bloodstream infection, review previous cases with C. pararugosa infections, and provide a concise review of the clinical background, risk factors, and brief the management of infections. A 3-year-old boy with a history of acute myeloid leukemia was hospitalized in Omid Hospital, Isfahan, Iran. Two consecutive blood cultures were taken from the peripheral vein and port catheter; after that, empirically meropenem was administered. Candida pararugosa were isolated from blood-based on conventional and molecular assays. Furthermore, the antifungal susceptibility profiles of the isolate were determined, which exhibited resistance to fluconazole (8 μg/mL). Antifungal therapy with caspofungin and removing the patient's port led to a significant clinical improvement of the patient's conditions. So far, in the literature review, 10 cases of clinical C. pararugosa isolates were found, of which 5 patients had bloodstream infections. Most patients with C. pararugosa infection presented with specific underlying conditions, such as malignancy, sarcoma, surgery, and adult acute myeloid leukemia. Patients with indwelling catheters run a high risk of acquiring C. pararugosa bloodstream infection. Therefore, special consideration should be given to opportunistic fungal infections in immunocompromised individuals using catheters.
Topics: Male; Adult; Humans; Child, Preschool; Antifungal Agents; Fluconazole; Catheter-Related Infections; Leukemia, Myeloid, Acute; Catheters; Sepsis; Microbial Sensitivity Tests; Drug Resistance, Fungal
PubMed: 37157053
DOI: 10.1007/s42770-023-00985-5 -
Medical Mycology Oct 2020Antifungal susceptibility profiles of rare Saccharomycotina yeasts remain missing, even though an increase in prevalence of such rare Candida species was reported in...
Antifungal susceptibility profiles of rare Saccharomycotina yeasts remain missing, even though an increase in prevalence of such rare Candida species was reported in candidemia. Majority of these rare yeast species carry intrinsic resistances against at least one antifungal compound. Some species are known to be cross-resistant (against multiple drugs of the same drug class) or even multi-drug resistant (against multiple drugs of different drug classes). We performed antifungal susceptibility testing (AFST) according to EUCAST broth microdilution for 14 rare species (Clavispora lusitaniae, Candida intermedia, Candida auris, Diutina rugosa, Wickerhamiella pararugosa, Yarrowia lipolytica, Pichia norvegensis, Candida nivariensis, Kluyveromyces marxianus, Wickerhamomyces anomalus, Candida palmioleophila, Meyerozyma guilliermondii, Meyerozyma caribbica, and Debaryomyces hansenii) known to cause candidemia. In total, 234 isolates were tested for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Amphothericin B had the broadest efficiency against the 14 tested rare yeast species, while high minimum inhibitory concentrations (MICs) against azole drugs and echinocandins were common. Voriconazole was the most efficient azole drug. Multidrug resistance was observed for the species C. auris and K. marxianus. Multidrug resistant individual isolates were found for Y. lipolytica and M. caribbica. In conclusion, the observed high MIC values of the rare Saccharomycotina species tested limit antifungal treatment options, complicating the management of such infections.
Topics: Antifungal Agents; Candidemia; Drug Resistance, Fungal; Fluconazole; Humans; Microbial Sensitivity Tests; Saccharomyces; Voriconazole
PubMed: 32043147
DOI: 10.1093/mmy/myaa005 -
Microorganisms Nov 2021Whey is the main byproduct of the dairy industry and contains sugars (lactose) and proteins (especially serum proteins and, at lesser extent, residual caseins), which...
Whey is the main byproduct of the dairy industry and contains sugars (lactose) and proteins (especially serum proteins and, at lesser extent, residual caseins), which can be valorized by the fermentative action of yeasts. In the present study, we characterized the spoilage yeast population inhabiting natural whey starter (NWS), the undefined starter culture of thermophilic lactic acid bacteria used in Parmigiano Reggiano (PR) cheesemaking, and evaluated thermotolerance, mating type, and the aptitude to produce ethanol and bioactive peptides from whey lactose and proteins, respectively, in a selected pool of strains. PCR-RFLP assay of ribosomal ITS regions and phylogenetic analysis of 26S rDNA D1/D2 domains showed that PR NWS yeast population consists of the well-documented , as well as of other species (, , and ), with multiple biotypes scored within each species as demonstrated by (GTG)-based MSP-PCR. Haploid and diploid strains were identified through genotyping, while thermotolerance assay allowed the selection of strains suitable to grow up to 48 °C. In whey fermentation trials, one thermotolerant strain was suitable to release ethanol with a fermentation efficiency of 86.5%, while another candidate was able to produce the highest amounts of both ethanol and bioactive peptides with potentially anti-hypertensive function. The present work demonstrated that PR NWS is a reservoir of ethanol and bioactive peptides producer yeasts, which can be exploited to valorize whey, in agreement with the principles of circularity and sustainability.
PubMed: 34835414
DOI: 10.3390/microorganisms9112288 -
Antonie Van Leeuwenhoek Nov 2023The use of yeasts as a feed supplement for cattle can promote animal development and performance. However, for the positive results to be consistent, strains with...
The use of yeasts as a feed supplement for cattle can promote animal development and performance. However, for the positive results to be consistent, strains with probiotic properties must be selected. The objective of this study was to isolate and identify yeasts present in the bovine feces and evaluate their probiotic potential together with strains previously isolated from the rumen (preliminary study). A total of 193 isolates were studied, including 139 isolates (19 species) from fecal samples from 11 different animals (Bos taurus and Bos indicus) and 54 strains previously isolated from rumen fluid (Bos taurus). The yeast population in the feces ranged from 3.51 to 4.99 log CFU/g, with Candida pararugosa being the most abundant (isolated from the feces of six samples analysed). Isolates were selected that had negative results in the safety tests (hemolytic activity, DNAse, and gelatinase) and had percentages greater than 35 and 70% for hydrophobicity and auto-aggregation, respectively. In addition, selected isolates had percentages greater than 77.7 and 74.7% for coaggregation with pathogenic strains of Escherichia coli and Clostridium perfringens, respectively. The isolates with percentage growth at 39 °C greater than 64.6% and viability greater than 96.7% were selected for survival testing under bovine gastrointestinal conditions. After the tests, the seven best isolates were selected, belonging to the species Candida pararugosa (L60, CCMA 928 and CCMA 930) and Pichia kudriavzevii (L97, L100, CCMA904, CCMA 907). The selected isolates were exopolysaccharide producers. Based on the results of the evaluated properties, the seven selected isolates were classified as potential probiotics for cattle.
Topics: Cattle; Animals; Saccharomyces cerevisiae; Gastrointestinal Tract; Feces; Escherichia coli; Probiotics
PubMed: 37650994
DOI: 10.1007/s10482-023-01865-6