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Medical Mycology Jun 2024In response to the growing global threat of fungal infections, in 2020 the World Health Organisation (WHO) established an Expert Group to identify priority fungi and...
In response to the growing global threat of fungal infections, in 2020 the World Health Organisation (WHO) established an Expert Group to identify priority fungi and develop the first WHO fungal priority pathogen list (FPPL). The aim of this systematic review was to evaluate the features and global impact of invasive infections caused by Pichia kudriavzevii (formerly known as Candida krusei). PubMed and Web of Science were used to identify studies published between 1 January 2011 and 18 February 2021 reporting on the criteria of mortality, morbidity (defined as hospitalisation and length of stay), drug resistance, preventability, yearly incidence, and distribution/emergence. Overall, 33 studies were evaluated. Mortality rates of up to 67% in adults were reported. Despite the intrinsic resistance of P. kudriavzevii to fluconazole with decreased susceptibility to amphotericin B, resistance (or non-wild-type rate) to other azoles and echinocandins was low, ranging between 0 and 5%. Risk factors for developing P. kudriavzevii infections included low birth weight, prior use of antibiotics/antifungals, and an underlying diagnosis of gastrointestinal disease or cancer. The incidence of infections caused by P. kudriavzevii is generally low (∼5% of all Candida-like blood isolates) and stable over the 10-year timeframe, although additional surveillance data are needed. Strategies targeting the identified risk factors for developing P. kudriavzevii infections should be developed and tested for effectiveness and feasibility of implementation. Studies presenting data on epidemiology and susceptibility of P. kudriavzevii were scarce, especially in low- and middle-income countries (LMICs). Thus, global surveillance systems are required to monitor the incidence, susceptibility, and morbidity of P. kudriavzevii invasive infections to inform diagnosis and treatment. Timely species-level identification and susceptibility testing should be conducted to reduce the high mortality and limit the spread of P. kudriavzevii in healthcare facilities.
Topics: Humans; Drug Resistance, Fungal; Antifungal Agents; World Health Organization; Pichia; Incidence; Risk Factors; Candidiasis
PubMed: 38935911
DOI: 10.1093/mmy/myad132 -
Foods (Basel, Switzerland) Jun 2024There is a growing market for craft beverages with unique flavors. This study aimed to obtain a palate-pleasing mead derived from 4A as a monoculture. Different culture...
There is a growing market for craft beverages with unique flavors. This study aimed to obtain a palate-pleasing mead derived from 4A as a monoculture. Different culture media were evaluated to compare the fermentation kinetics and final products. The crucial factors in the medium were ~200 mg L of yeast assimilable nitrogen and a pH of 3.5-5.0. A panel of judges favored the mead derived from 4A (fermented in a medium with honey initially at 23 °Bx) over a commercial sample produced from , considering its appearance, fruity and floral flavors (provided by esters, aldehydes, and higher alcohols), and balance between sweetness (given by the 82.91 g L of residual sugars) and alcohol. The present mead had an 8.57% / ethanol concentration, was elaborated in 28 days, and reached a maximum biomass growth (2.40 g L) on the same fermentation day (6) that the minimum level of pH was reached. The biomass growth yield peaked at 24 and 48 h (~0.049 g g), while the ethanol yield peaked at 24 h (1.525 ± 0.332 g g), in both cases declining thereafter. The Gompertz model adequately describes the kinetics of sugar consumption and the generation of yeast biomass and ethanol. Pathogenic microorganisms, methanol, lead, and arsenic were absent in the mead. Thus, 4A produced a safe and quality mead with probable consumer acceptance.
PubMed: 38928890
DOI: 10.3390/foods13121948 -
Updates: Outbreak Evaluation through Molecular Assays and Antifungal Stewardship-A Narrative Review.Current Issues in Molecular Biology Jun 2024was reported by the WHO as second to , in the list of nineteen fungal priority pathogens, along with two species with a new nomenclature, () and (). This novel... (Review)
Review
was reported by the WHO as second to , in the list of nineteen fungal priority pathogens, along with two species with a new nomenclature, () and (). This novel classification was based on antifungal resistance, the number of deaths, evidence-based treatment, access to diagnostics, annual incidence, and complications and sequelae. We assessed which molecular assays have been used to diagnose outbreaks in the last five years. Using "; outbreak; molecular detection" as keywords, our search in PubMed revealed 32 results, from which we selected 23 original papers published in 2019-2024. The analyzed studies revealed that the detection methods were very different: from the VITEK® 2 System to MALDI TOF (Matrix-Assisted Laser Desorption Ionization-Time of Flight), NGS (Next-Generation Sequencing), WGS (Whole Genome Sequencing), and commercially available real-time PCR (Polymerase Chain Reaction) assays. Moreover, we identified studies that detected antifungal resistance genes (e.g., FKS for echinocandins and ERG11 for azoles). The analyzed outbreaks were from all continents, which confirms the capability of this yeast to spread between humans and to contaminate the environment. It is important that real-time PCR assays were developed for accurate and affordable detection by all laboratories, including the detection of antifungal resistance genes. This will allow the fast and efficient implementation of stewardship programs in hospitals.
PubMed: 38921033
DOI: 10.3390/cimb46060362 -
Letters in Applied Microbiology Jun 2024Yeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their...
Yeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their nutritional benefits. Despite their potential, marine and mangrove yeast species used in the aquaculture industry have received little attention in the Philippines. Pichia kudriavzevii (A2B R1 ISO 3), sourced from bark samples, was selected and mass-produced due to its high protein content and amino acid profile. The dried biomass of P. kudriavzevii was incorporated into the diets of Nile tilapia (Oreochromis niloticus) juveniles at varying inclusion levels (0, 1, 2, and 4 g/kg diet) and its effect on their growth performance, body composition, and liver and intestinal morphology was assessed after 40 days of feeding. The groups that received P. kudriavzevii at a concentration of 2 g/kg diet exhibited higher final body weight, percent weight gain, and specific growth rate in comparison to the other treatment groups. Whole body proximate composition did not vary among the dietary groups. Intestinal and liver histopathology also indicated no abnormalities. These findings suggest the potential of ascomycetous P. kudriavzevii as a beneficial feed additive in Nile tilapia diets, warranting further investigation into its long-term effects and broader applications in fish culture.
Topics: Animals; Animal Feed; Cichlids; Pichia; Aquaculture; Diet; Liver; Intestines; Dietary Supplements; Philippines
PubMed: 38906842
DOI: 10.1093/lambio/ovae057 -
Journal of Dairy Science Jun 2024Objectives were to determine the effects of 2 dietary microbial additives supplemented to diets of Holstein cows on productive performance and feed efficiency....
Objectives were to determine the effects of 2 dietary microbial additives supplemented to diets of Holstein cows on productive performance and feed efficiency. One-hundred and 17 Holstein cows were enrolled at 61 d (31 to 87 d) postpartum in a randomized complete block design experiment. Cows were blocked by parity group, as nulliparous or multiparous cows and, within parity, by pre-treatment energy-corrected milk yield. Within block, cows were randomly assigned to one of 3 treatments administered as top-dress for 140 d. Treatments consisted of either 100 g of corn meal containing no microbial additive (CON; 15 primiparous and 25 multiparous), 100 g of corn meal containing 5 g of a mixture of Clostridium beijerinckii and Pichia kudriavzevii (G1; 4 × 10 cfu of C. beijerinckii and 1 × 10 cfu of P. kudriavzevii; 14 primiparous and 24 multiparous), or 100 g of corn meal containing 5 g of a mixture of C. beijerinckii, P. kudriavzevii, Butyrivibrio fibrisolvens, and Ruminococcus bovis (G2; 4 × 10 cfu of C. beijerinckii, 1 × 10 cfu of P. kudriavzevii, 1 × 10 cfu of B. fibrisolvens, and 1 × 10 cfu of R. bovis; 15 primiparous and 24 multiparous). Intake of DM, milk yield, and BW were measured daily, whereas milk composition was analyzed at each milking 2 d a week, and body condition was scored twice weekly. Milk samples were collected on d 60 and 62 in the experiment and analyzed for individual fatty acids. The data were analyzed with mixed-effects models with orthogonal contrast to determine the impact of microbial additive (MA; CON vs. 1/2 G1 + 1/2 G2) and type of microbial additive (TMA; G1 vs. G2). Results are described in sequence as CON, G1, and G2. Intake of DM (22.2 vs. 22.4 vs. 22.4 kg/d), BW (685 vs. 685 vs. 685 kg) and the daily BW change (0.40 vs. 0.39 vs. 0.39 kg/d) did not differ among treatments; however, feeding MA tended to increase BCS (3.28 vs. 3.33 vs. 3.36). Supplementing MA increased yields of milk (39.9 vs. 41.3 vs. 41.5 kg/d), ECM (37.9 vs. 39.3 vs. 39.9 kg/d), fat (1.31 vs. 1.37 vs. 1.40 kg/d), total solids (4.59 vs. 4.75 vs. 4.79 kg/d), and ECM per kg of DMI (1.72 vs. 1.76 vs. 1.80 kg/kg). Furthermore, cows fed MA increased yields of pre-formed fatty acids in milk fat (>16C; 435 vs. 463 vs. 488 g/d), particularly unsaturated fatty acids (367 vs. 387 vs. 410 g/d), such as linoleic (C18:2 cis-9, cis-12; 30.9 vs. 33.5 vs. 35.4 g/d) and α-linolenic acids (C18:3 cis-9, cis-12, cis-15; 2.46 vs. 2.68 vs. 2.82 g/d) on d 60 and 62 in the experiment. Collectively, supplementing G1 and G2 improved productive performance of cows with no differences between the 2 MA.
PubMed: 38876222
DOI: 10.3168/jds.2024-24795 -
Iranian Journal of Microbiology Apr 2024The presence of fungi in the respiratory tract as mycobiome, particularly species (spp.), remains a serious problem due to increasing numbers of immunocompromised...
BACKGROUND AND OBJECTIVES
The presence of fungi in the respiratory tract as mycobiome, particularly species (spp.), remains a serious problem due to increasing numbers of immunocompromised patients. The confirmed reliable existence of these pathogens due to frequent colonization is essential. This investigation aimed to recognize spp. among isolates from bronchoalveolar lavage of immunocompromised and critically ill patients and to evaluate their susceptibility to antimycotic drugs.
MATERIALS AND METHODS
Bronchoalveolar lavage fluid was collected from 161 hospitalized patients presenting with suspected respiratory fungal infection /colonization. The specimens were examined by standard molecular and mycological assays. spp. were recognized with sequence assessment of the D1-D2 section of the large subunit ribosomal DNA. The susceptibility of isolates to common antimycotic drugs was distinguished by standard broth microdilution.
RESULTS
Seventy-one clinical isolates of spp. were recognized. was the most frequent, followed by (), and We found 5.1% of isolates and 8% of isolates to show resistance to fluconazole. The whole of the spp. were sensitive to amphotericin B and caspofungin.
CONCLUSION
This study demonstrated that and are the most common isolates of bronchoalveolar lavage fluid in patients, and the drug susceptibility screening confirmed that amphotericin B and caspofungin are effective against spp. but some and isolates showed resistance to fluconazole.
PubMed: 38854989
DOI: 10.18502/ijm.v16i2.15362 -
Food Chemistry: X Jun 2024Kombucha is a traditional beverage produced by a living culture known as SCOBY or "symbiotic culture of bacteria and yeast". Culture-dependent production is essential...
Kombucha is a traditional beverage produced by a living culture known as SCOBY or "symbiotic culture of bacteria and yeast". Culture-dependent production is essential for stable kombucha fermentation. The aim of this study was to design a microbial community and to determine the effect of that community on the flavor and chemical properties of kombucha. The fermentations were carried out using combinations of selected species including and , which were previously isolated from kombucha. The effects of monocultures and cocultures on fermentation were investigated. The highest acetic acid producer was , which has strong antioxidant properties. In the monoculture and coculture fermentations, aldehydes, acids, and esters were generally observed at the end of fermentation. This study confirms that microbiota reconstruction is a viable approach for achieving the production of kombucha with increased bioactive constituents and consumer acceptance.
PubMed: 38808165
DOI: 10.1016/j.fochx.2024.101469 -
Archives of Microbiology May 2024Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified...
Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified 60 yeast strains from the natural fermentation broth of Sidamo coffee beans to screen for indigenous beneficial yeasts. Among them, 25 strains were obtained through morphological characterization on nutritional agar medium from Wallerstein Laboratory (WL), with molecular biology identifying Saccharomyces cerevisiae strain YBB-47 and the remaining 24 yeast strains identified as Pichia kudriavzevii. We investigated the fermentation performance, alcohol tolerance, SO tolerance, pH tolerance, sugar tolerance, temperature tolerance, ester production capacity, ethanol production capacity, HS production capacity, and other brewing characteristics of YBB-33 and YBB-47. The results demonstrated that both strains could tolerate up to 3% alcohol by volume at a high sucrose mass concentration (400 g/L) under elevated temperature conditions (40 ℃), while also exhibiting a remarkable ability to withstand an SO mass concentration of 300 g/L at pH 3.2. Moreover, S. cerevisiae YBB-47 displayed a rapid gas production rate and strong ethanol productivity. whereas P. kudriavzevii YBB-33 exhibited excellent alcohol tolerance. Furthermore, this systematic classification and characterization of coffee bean yeast strains from the Sidamo region can potentially uncover additional yeasts that offer high-quality resources for industrial-scale coffee bean production.
Topics: Fermentation; Saccharomyces cerevisiae; Pichia; Ethanol; Hydrogen-Ion Concentration; Coffee; Coffea; Temperature; Seeds; Hydrogen Sulfide
PubMed: 38805051
DOI: 10.1007/s00203-024-04017-0 -
Microorganisms May 2024Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador's animal feed industry. The emergence of yellow-orange fungal growth in...
Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador's animal feed industry. The emergence of yellow-orange fungal growth in PKC on some cattle farms in Ecuador sparked concerns within the cattle industry regarding a potential mycotoxin-producing fungus on this substrate. Due to the limited availability of analytical chemistry techniques in Ecuador for mycotoxin detection, we chose to isolate and identify the fungus to determine its association with mycotoxin-producing genera. Through molecular identification via ITS region sequencing, we identified the yellow-orange fungus as the yeast . Furthermore, we isolated two other fungi-the yeast , and the fungus Molecular identification confirmed that all three species are not classified as mycotoxin-producing fungi but in contrast, the literature indicates that all three have demonstrated antifungal activity against and species, genera associated with mycotoxin production. This suggests their potential use in biocontrol to counter the colonization of harmful fungi. We discuss preventive measures against the fungal invasion of PKC and emphasize the importance of promptly identifying fungi on this substrate. Rapid recognition of mycotoxin-producing and pathogenic genera holds the promise of mitigating cattle intoxication and the dissemination of mycotoxins throughout the food chain.
PubMed: 38792767
DOI: 10.3390/microorganisms12050937 -
Microorganisms May 2024Because data on the fungal gut community structure of African children are scarce, we aimed to describe it by reanalysing rRNA ITS1 and ITS2 metabarcoding data from a...
Because data on the fungal gut community structure of African children are scarce, we aimed to describe it by reanalysing rRNA ITS1 and ITS2 metabarcoding data from a study designed to assess the influence of microbiota in malaria susceptibility in Malian children from the Dogon country. More specifically, we aimed to establish the core gut mycobiome and compare the gut fungal community structure of breastfed children, aged 0-2 years, with other age groups. Briefly, DNA was extracted from 296 children's stool samples. Both rRNA ITS1 and ITS2 genomic barcodes were amplified and subjected to Illumina MiSeq sequencing. The ITS2 barcode generated 1,975,320 reads and 532 operational taxonomic units (OTUs), while the ITS1 barcode generated 647,816 reads and 532 OTUs. The alpha diversity was significantly higher by using the ITS1 compared to the ITS2 barcode ( < 0.05); but, regardless of the ITS barcode, we found no significant difference between breastfed children, aged 0-2 years, compared to the other age groups. The core gut mycobiome of the Malian children included , , , , and section , which were present in at least 50% of the 296 children. Further studies in other African countries are warranted to reach a global view of African children's core gut mycobiome.
PubMed: 38792756
DOI: 10.3390/microorganisms12050926