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Oral Oncology Nov 2023Head and neck cancer (HNC) impairs patient immunity and increases susceptibility to oral fungal infections (OFIs). Effectively treating such infections requires accurate...
OBJECTIVES
Head and neck cancer (HNC) impairs patient immunity and increases susceptibility to oral fungal infections (OFIs). Effectively treating such infections requires accurate identification of the causative pathogens. This study aimed to characterize the mycobiota profile of OFIs in HNC patients undergoing radiation treatment (RT).
MATERIALS AND METHODS
A 6-year retrospective analysis of oral mucosal samples from HNC patients with a history of RT and OFIs between 2014 and 2019 was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) profiling. Samples from the Clinical Microbiology Laboratory at Karolinska University Hospital were evaluated for mycobiota diversity and species co-occurrence patterns in the ongoing-RT and post-RT groups.
RESULTS
A total of 190 oral fungi (88% Candida, 5% Pichia) were isolated from 162 HNC patients receiving RT. In the ongoing-RT group, the emergent non-albicans Candida (NAC) species; F. solani and C. jadinii, were detected for the first time. The dominant pathogens in both ongoing and post-RT groups were C. albicans, C. glabrata, P. kudriavzevii, C. parapsilosis, and C. tropicalis, as shown by Venn analysis. Network analysis revealed greater fungi diversity and multi-species co-occurrence in the ongoing-RT group. C. albicans commonly co-occurred with C. glabrata in both ongoing-RT (21%) and post-RT groups (30%).
CONCLUSION
MALDI-TOF MS identified a wide range of oral fungal species in HNC patients receiving RT. While C. albicans remains the most prevalent OFIs pathogen, multi-species co-occurrence and novel NACs were noted. Understanding the ecological interactions among these causative pathogens could significantly advance the development of effective therapeutics for treating OFIs in HNC patients.
Topics: Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Retrospective Studies; Candida; Mycoses; Head and Neck Neoplasms
PubMed: 37611433
DOI: 10.1016/j.oraloncology.2023.106556 -
Food Science & Nutrition Aug 2023Soybean paste was a traditional fermented product in northeast China, mainly fermented by molds, yeast, , and lactic acid bacteria. In this study, the safety and...
Soybean paste was a traditional fermented product in northeast China, mainly fermented by molds, yeast, , and lactic acid bacteria. In this study, the safety and fermentation ability of lactic acid bacteria and yeast strains isolated from traditional soybean paste in northeast China were evaluated, and the dynamic changes of biogenic amines, aflatoxin, total acids, amino acid nitrogen, and volatile compounds were investigated during the fermentation of the traditional soybean paste. Among the tested strains, DPUL-J8 could decompose putrescine by 100%, and no biogenic amine was produced by DPUY-J8. DPUL-J8 and DPUY-J8 with strong biogenic amine degrading capacities were inoculated into the soybean paste. After 30 days of fermentation, the content of biogenic amines and aflatoxin in the fermented soybean paste declined by more than 60% and 50%, respectively. At the same time, compared with the control group without inoculation, the contents of total acid (1.29 ± 0.05 g/100 g), amino acid nitrogen (0.82 ± 0.01 g/100 g), and volatile compounds in soybean paste fermented by DPUL-J8 and DPUY-J8 were significantly increased, which had a good flavor. These results indicated that the use of DPUL-J8 and DPUY-J8 as starter cultures for soybean paste might be a good strategy to improve the safety and flavor of traditional Chinese soybean paste.
PubMed: 37576040
DOI: 10.1002/fsn3.3372 -
Mycopathologia Dec 2023We performed a retrospective survey of non-Candida albicans candidemia in patients with cancer, including those with solid tumors and those with hematological...
We performed a retrospective survey of non-Candida albicans candidemia in patients with cancer, including those with solid tumors and those with hematological malignancies as well as transplants patients both, solid-organ transplant recipients and hematopoietic stem cell transplant recipients. The study was performed at two healthcare centers in New York City and covered the years 2018-2022. A total of 292 patients (318 isolates) were included in the study. In order of frequency, C. glabrata (38%) was the most common species recovered, followed by C. parapsilosis (19.2%), C. tropicalis (12.6%), C. krusei (10.7%), C. lusitaniae (5.7%), and C. guilliermondii (4.4%). Micafungin was the most common antifungal treatment and 18.5% of patients were on antifungal prophylaxis. The 30-day crude mortality was 40%. 4.5% of patients had more than one non-albicans species detected. In conclusion, this study represents one of the largest surveys of non-albicans species in cancer and transplant patients and provides data on the current epidemiology of these Candida species in this patient population.
Topics: Humans; Antifungal Agents; Transplant Recipients; Retrospective Studies; Microbial Sensitivity Tests; Candida; Candidemia; Candida glabrata; Candida parapsilosis; Candida tropicalis; Neoplasms
PubMed: 37365379
DOI: 10.1007/s11046-023-00765-7 -
International Journal of Food... Aug 2023The increasing demand for more flavored and complex beers encourages the investigation of novel and non-conventional yeasts with the ability to provide a combination of...
The increasing demand for more flavored and complex beers encourages the investigation of novel and non-conventional yeasts with the ability to provide a combination of bioflavoring and low ethanol yields. The present study identified 22 yeasts isolated from different brewing sources, including the fermentation by-products known as yeast sludges, and characterized a selection of strains to find the more suitable for the aforementioned aims. HPLC and GC-FID analysis of its brewing products were performed. The most promising results were obtained with the non-conventional yeasts Pichia kudriavzevii MBELGA61 and Meyerozyma guilliermondii MUS122. The former, isolated from a Belgian wheat beer sludge, was capable of growing in wort (17.0°Bx., 20 °C) with very low ethanol yields (1.19 % v/v). Besides, upon mixed fermentations with Saccharomyces cerevisiae, was suitable to produce volatile compounds such as ethyl acetate, 2-phenyl ethanol and isoamyl alcohol, with characteristic fruity notes. M. guilliermondii MUS122, isolated from a golden ale beer sludge, partially attenuated the wort with low production of ethanol and biomass. In addition, provided some fruity and floral nuances to the aroma profile of mixed fermentations with brewer's yeast. The results suggest that these strains favor the development of more fruity-flowery aroma profiles in beers. Furthermore, they are suitable for use in mixed fermentations with Saccharomyces brewer's strains, although the ethanol level did not decrease significantly.
Topics: Fermentation; Beer; Sewage; Yeasts; Saccharomyces cerevisiae; Ethanol
PubMed: 37244227
DOI: 10.1016/j.ijfoodmicro.2023.110254 -
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