Candida Catenulata Research Articles

Magnetic whole-cell biocatalyst based on intracellular lipases of Candida catenulata as promising technology for green synthesis of epoxy fatty acids

This study focuses on the development a green synthesis of epoxy fatty acids (EFAs) which are commonly used as the plasticizer in polymer industries. The intracellular lipases of Candida catenulata cells as a whole-cell biocatalyst (WCB) were examined in the bio-epoxidation of free fatty acids (FFAs) with hydrogen peroxide. The FFAs in soybean soap stock, an industrial by-product of vegetable oil factories, was used as the feedstock of the process. To remove phosphates from soap stock a degumming process was tested before the bio-epoxidation reaction and results revealed that the EFAs yield was improved using the degummed fatty acids (DFAs). The attachments of magnetic Fe3O4 nanoparticles to the surface of WCBs facilitated the recovery of the biocatalyst, and were improved stabilities. The activation energy for the magnetic whole-cell biocatalysts (MWCB) was 48.54 kJ mol−1, which was lower than the WCB system (51.28 kJ mol−1). The EFA yield was about 47.1 % and 33.8 % after 3 h for the MWCBs and 2 h for the WCBs, respectively. The MWCBs displayed acceptable reusability in the repetitious bio-epoxidation reaction with maintaining 59 % of the original activity after 5 cycles whereas the performance of the WCBs was 5.9 % at the same conditions. The effects of influential factors such as reaction time, molar ratio of H2O2 to CC, and batch and semi-batch operations were investigated for both biocatalyst systems. The quality of EFAs was characterized by FTIR and GC-MS analyses.

Virulence factors, antifungal susceptibility and molecular profile in Candida species isolated from the hands of health professionals before and after cleaning with 70% ethyl alcohol-based gel

Fungal infections in neonatal intensive care units (NICU) are mainly related to Candida species, with high mortality rates. They are predominantly of endogenous origin, however, cross-infection transmitted by healthcare professionals' hands has occurred. The aim of this study was to identify Candida species isolated from the hands of healthcare professionals in a NICU before and after hygiene with 70% ethanol-based gel and evaluate virulence factors DNase, phospholipase, proteinase, hemolysin, biofilm biomass production, and metabolic activity. In vitro antifungal susceptibility testing and similarity by random amplified polymorphic DNA (RAPD) were also performed. C. parapsilosis complex was the most frequent species (57.1%); all isolates presented at least one virulence factor; three isolates (Candida parapsilosis complex) were resistant to amphotericin B, two (Candida famata [currently Debaryomyces hansenii] and Candida guilliermondii [currently Meyerozyma guilliermondii]) was resistant to micafungin, and six (Candida parapsilosis complex, Candida guilliermondii [=Meyerozyma guilliermondii], Candida viswanathi, Candida catenulata [currently Diutina catenulata] and Candida lusitaniae [currently Clavispora lusitaniae]) were resistant to fluconazole. Molecular analysis by RAPD revealed two clusters of identical strains that were in the hands of distinct professionals. Candida spp. were isolated even after hygiene with 70% ethanol-based gel, highlighting the importance of stricter basic measures for hospital infection control to prevent nosocomial transmission.

Yeast fungi in the etiology of animal mycoses

760 samples of biological material from various regions of the Russian Federation were studied, 320 isolates of yeast fungi were isolated, which amounted to 42.10% of the total number of samples. Of the 760 samples, 29.0% belonged to cattle, 11.8% to small cattle, 13.0% to horses, 1.6% to camels, 7.2% to cats and 17.5% to dogs, 1.8% to raw milk and 0.8% to environmental objects (OVS). Most of the isolated isolates (240) of yeast fungi belonged to fungi of the genus Candida, which amounted to 75%. The species diversity of fungi of the genus Candida is represented by 15 species. The largest number of isolates belong to the species Candida albicans, Candida catenulata, Candida kefyr Candida krusei, Candida membranifaciens, Candida pararugosa and Candida tropicals. These species of fungi of the genus Candida are known as pathogens of fungal infections in humans and animals. The species diversity of species not belonging to the genus Candida is limited to 7 species in 5 genera – Geotrichum, Malassezia, Rhodotorula, Saccharomyces and Trichosporon. The fact of the development of resistance of some yeast species to the most commonly used antifungal drugs (fluconazole and voriconazole) has been established. It was revealed that 30% of the studied isolates of the genus Candida are resistant to fluconazole, 32% are dose–dependent, 38% are sensitive, 28% are resistant to voriconazole, 30% are dose–dependent, 42% are sensitive. Isolates not belonging to the genus Candida showed resistance to fluconazole 19%, 38% - dose–dependent, 43% - sensitive, voriconazole – 23% – resistant, 18% – dose–dependent and 59% - sensitive. The proportion of isolates of yeast fungi resistant to fluconazole and voriconazole isolated from animals is quite large, in some cases it is up to 50% (C. tropicalis). A high level of resistance was found in isolates of Candida albicans, Candida catenulata, Candida rugosa and Candida pararugosa, which can significantly complicate the treatment of infections caused by them and contribute to the worldwide problem of antibiotic resistance.

Handling the inhibitory role of product accumulation during sophorolipid fermentation in a bubble column reactor with an in situ foam recovery.

Sophorolipid (SL) production by Candida catenulata from sunflower fatty acids was studied in a bubble column reactor (BCR). The specific oxygen uptake rate was 0.021mggcell-1 min-1 which indicates the importance of aeration in SL biosynthesis. The measurement of oxygen transfer rate (OTR) in the BCR showed a satisfactory OTR value of about 0.093min-1 in the system. However, further SL production was stopped after 30h in the BCR mainly due to the product accumulation in the culture and its inhibitory effects on cell growth and SL synthesis. Since an extensive foam was generated in the BCR under the absence of an antifoam agent, the development of an in situ foam recovery system provided the integration of production and separation of SL to handle the problem. The application of the foam recovery system enhanced biomass and titer SL concentration by 38.5 and 28.2% in comparison with the conventional BCR, respectively. Further studies in the system were performed by monitoring the size of bubbles and their effects on the biomass and SL enrichment in the foam stream at different aeration rates where the SL enrichment varied from 900 to 100% at 12 and 50h of the fermentation.

Kinetic studies and dynamic modeling of sophorolipids production by Candida catenulata using different carbon sources

Abstract The kinetic study on sophorolipids (SLs) production by Candida catenulata from glucose, raw sunflower soapstock was investigated at different initial concentrations ranging from 0 to 100 g L−1. The Monod model with a maximum specific growth rate (μ max) of 0.0167 h−1 and half-saturation coefficient (K S ) of 6.91 g L−1 best described the cell growth kinetics of C. catenulata on glucose. The best-fitted constants of the Monod model for raw sunflower soapstock were μ max = 0.0157 h−1 and K S = 16.01 g L−1. Determination of Luedeking-Piret constants indicated SLs mainly produced as an associated growth product in the systems. Dynamic features of the fermentation were modeled using the obtained constants and results showed the prediction power of the developed model in describing the behavior of the process. Also, a modified kinetic model was developed for the dynamic modeling of the dual carbon sources system.

Degumming Process of Vegetable Oil Soap Stocks and Their Applications to Biological Surfactant Production by Candida catenulata

Degumming Process of Vegetable Oil Soap Stocks and Their Applications to Biological Surfactant Production by Candida catenulata

Immobilization of Candida catenulata cells by surface-loading of an amino-functionalized Fe3O4 nanoparticles and its application as the sustainable whole-cell biocatalyst for enzymatic biodiesel production

In this study, the intracellular lipases of Candida catenulata were examined as a whole-cell biocatalyst (WCB) of soybean oil transesterification and obtained a fatty acid methyl ester (FAME) yield of 79.1%. To facilitate the biocatalyst recovery and improve its stability, the WCB was attached to magnetic Fe3O4 nanoparticles activated by a linear structure of polyethyleneimine (PEI) as the multi-amino-functionalized arm. The preparation procedure of the magnetic whole-cell biocatalysts (MWCBs) was optimized by considering the pH during immobilization (X1), the weight ratio of nanoparticles-to-cell (X2), and PEI concentration (X3) using the response surface methodology. The best optimal setting of the variables was determined at X1 of 6.1, X2 of 0.6, and X3 of 0.7 w% with the transesterification activity of 7.6 × 105 IU gbiocatalyst−1 gained a FAME yield of 78.4% after 3 h. The MWCBs showed an improvement in thermal stability where the optimal temperature was shifted from 34C to 38 °C and the deactivation energy was increased from 183.9 kJ mol−1 and 223.6 kJ mol−1 after the immobilization. The MWCBs displayed satisfactory sustainability in the repeated transesterification experiments and maintained 87.3% of the original activity after 10 cycles which was higher than the bare-WCB system with a recovery of 57.4%.

Free fatty acids in sunflower oil soap stock progressed the sophorolipid production by Candida catenulata

AbstractSophorolipids are a group of surface‐active glycolipid compounds that can be synthesized by several yeasts, especially the Candida genera. Soap stock is a by‐product of vegetable oils refinery that enriches mono‐unsaturated fatty acids, and its application is interesting as a low‐cost industrial residue in sophorolipid production. In this study, the sophorolipid production was evaluated by Candida catenulate KP324968, using sunflower oil soap stock and glucose as the hydrophobic and hydrophilic carbon sources, respectively. The results indicated the ratio of hydrophobic to a hydrophilic carbon source, initial pH, and type of nitrogen source had significant roles in the performance of the cells. The highest specific biomass growth rate was about 0.0447 ± 0.0013 h−1 and a sophorolipid production rate of 49.96 ± 0.33 mg L−1 h−1 was obtained at a soap stock‐to‐glucose ratio of 1, initial pH of 5.5, and temperature of 30°C. The addition of organic nitrogen sources such as yeast extract and urea obtained a higher sophorolipid production in comparison with ammonium nitrate and potassium nitrate as the mineral nitrogen sources. Usage of both yeast extract and urea increased the sophorolipid production rate by 4.4% and 6.9%, in comparison with separate usage of yeast extract and urea, respectively. The characterization of the sophorolipid confirmed an emulsification index of about 30 ± 2.9% for diesel‐in‐water and 50 ± 3.5% for sunflower oil‐in‐water systems. The critical micelle concentration was determined at 280 mg L−1. The produced sophorolipid at a concentration of 500 mg L−1 showed an antibacterial capacity about of 95.4 ± 1.1%, and 44.7 ± 0.8% against Bacillus subtilis (Gram‐positive) and Escherichia coli (Gram‐negative) bacteria, respectively.

Fungal community and physicochemical profiles of ripened cheeses from the Canastra of Minas Gerais, Brazil.

Canastra's Minas artisanal cheese [QMA (Minas artisanal cheese)] is a protected geographical indication traditional food. The influence of fungi on the cheese ripening process is of great importance. This study aimed to apply culture-dependent and -independent methods to determine the mycobiota of QMA produced in the Canastra region, as well as to determine its physicochemical characteristics. Illumina-based amplicon sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were the culture-independent methods used. The physicochemical analysis results showed that the QMA has a moisture content ranging 18.4-28.2%, fat content ranging 20.5-40%, sodium chloride percentage of approximately 0.9%, and pH ranging 5.2-5.5. The population of fungi ranged between 6.3 and 8log colony-forming unit/g. Fusarium spp., Geotrichum candidum, Paecilomyces spp., Trichosporon coremiiforme, Candida catenulata, Aspergillus spp., Trichosporon japonicum, Aspergillus oryzae, Kluyveromyces spp., Torulaspora spp., and Debaryomyces spp. were the most prevalent fungi. The methods used to evaluate the mycobiota provide a better understanding of which species are present in the final product and eventually contribute to the characteristics of QMA. Geotrichum candidum and C. catenulata were identified as promising species for future studies on product quality.

In Vitro Antifungal Activity of Ibrexafungerp (SCY-078) Against Contemporary Blood Isolates From Medically Relevant Species of Candida: A European Study.

BackgroundIbrexafungerp (SCY-078) is the newest oral and intravenous antifungal drug with broad activity, currently undergoing clinical trials for invasive candidiasis.ObjectiveThe aim of this study was to assess the in vitro activity of ibrexafungerp and comparators against a collection of 434 European blood isolates of Candida.MethodsIbrexafungerp, caspofungin, fluconazole, and micafungin minimum inhibitory concentrations (MICs) were collected from 12 European laboratories for 434 blood isolates, including 163 Candida albicans, 108 Candida parapsilosis, 60 Candida glabrata, 40 Candida tropicalis, 29 Candida krusei, 20 Candida orthopsilosis, 6 Candida guilliermondii, 2 Candida famata, 2 Candida lusitaniae, and 1 isolate each of Candida bracarensis, Candida catenulata, Candida dubliniensis, and Candida kefyr. MICs were determined by the EUCAST broth microdilution method, and isolates were classified according to recommended clinical breakpoints and epidemiological cutoffs. Additionally, 22 Candida auris from different clinical specimens were evaluated.ResultsIbrexafungerp MICs ranged from 0.016 to ≥8 mg/L. The lowest ibrexafungerp MICs were observed for C. albicans (geometric MIC 0.062 mg/L, MIC range 0.016–0.5 mg/L) and the highest ibrexafungerp MICs were observed for C. tropicalis (geometric MIC 0.517 mg/L, MIC range 0.06–≥8 mg/L). Modal MICs/MIC50s (mg/L) against Candida spp. were 0.125/0.06 for C. albicans, 0.5/0.5 for C. parapsilosis, 0.25/0.25 for C. glabrata, 0.5/0.5 for C. tropicalis, 1/1 for C. krusei, 4/2 for C. orthopsilosis, and 0.5/0.5 for C. auris. Ibrexafungerp showed activity against fluconazole- and echinocandin-resistant isolates. If adopting wild-type upper limits, a non-wild-type phenotype for ibrexafungerp was only observed for 16/434 (3.7%) isolates: 11 (4.6%) C. parapsilosis, 4 (5%) C. glabrata, and 1 (2.5%) C. tropicalis.ConclusionIbrexafungerp showed a potent in vitro activity against Candida.

Effect of some mutagenic compounds on lipase production by fluconazole-treated Candida catenulata

Lipases (triacylglycerol acylhydrolases, E.C. 3.1.1.3) are enzymes widely applied in industry and medicine. Our previous study showed that Candida catenulata produced much higher lipase activity in presence of 150 mg fluconazole than that in untreated control. Consequently in this study, optimization of fluconazole-treated C. catenulata for maximum lipase production was carried out. Fluconazole-treated C. catenulate cultured on medium containing 2.5% Tween 80 as carbon source, 0.7% yeast extract as nitrogen source, and 10 mM CuSO4.5H2O. pH 5.5, dark incubation at 37 °C under dark agitation for 3 days expressed the optimum physiological variables for maximum lipase production. Transmission electron microscopy (TEM) of the native cell (control) of C. catenulata declared a typical morphology of Candida cell with a uniform central density, typical structured nucleus, and a cytoplasm with several elements of endomembrane system and enveloped by a regular intact cell wall. The TEM photomicrograph of 150 mg fluconazole-treated cells of C. catenulata showed that the ultrastructures of treated C. catenulata displayed many noticeable morphological changes. The effect of mutagens [sodium azide (SA), ethidium bromide (EtBr), ethanol (EtOH)] was assayed on the lipase activity from C. catenulata. All mutagenic compounds with different concentrations decreased the lipase activity. Yeast specific activity, protein concentrations, and dry biomass gradually reached their highest decline at mutagen-elevated concentrations. Combination of lower concentrations of mutagen (0.1 µg/ml EtBr + 0.5 mM SA + 10% EtOH, Comb-Fl) exerted synergistic inhibition action and reduced C. catenulata virulent factor (lipase) over their single treatment. When 150 mg fluconazole was added to the mutagen’s combination mixture (Comb + Fl), an increase in the production of the virulence factor lipase by C. catenulata was detected. This action indicated the antagonistic effect of fluconazole over the mutagen combination mixture in increasing the fungal pathogenicity.

Antifungal susceptibility profile and biofilm production of Candida spp. isolated from catheterised patients with urinary tract infection

BACKGROUND: Candida species, which are present as normal flora in healthy individuals, are known to cause opportunistic infections with high rates of mortality, especially in immunocompromised individuals. Urinary tract infection (UTI) is the most common type of nosocomial infection, and about 10%-15% of them are due to Candida species. Catheter-associated infections due to Candida spp. are mainly due to biofilm formation.OBJECTIVE: This study aims to speciate Candida isolates from catheterised patients with UTI infection and to compare the antifungal susceptibility pattern with their biofilm production.MATERIALS AND METHODS: A total of 55 Candida species were isolated from the urine samples of catheterised patients with UTIs over a period of nine months. Patients' demographic details and risk factors were collected. All the isolates were identified and confirmed by routine phenotypic and genotypic techniques. The rare species that could not be identified by routine techniques were identified by sequencing the internal transcribed spacer region. Biofilm production was detected by tube method, and the antifungal susceptibility testing was done by broth microdilution method (CLSI M27-A3 guidelines).RESULTS: In our study, 55 Candida species were identified, among which the most predominant species was found to be Candida tropicalis 23 (42%). Among 48 biofilm producers (87.2%), only 2 (4.1%) isolates of Candida albicans and 3 (6.2%) isolates of C. tropicalis were resistant to Amphotericin B and Fluconazole. The MIC values for Amphotericin B, Fluconazole and Itraconazole were high in both Candida auris (2) and Candida lusitaniae (1), although one isolate of each species was a potent biofilm producer. In Candida catenulata (4), three isolates had high MIC value for Amphotericin B and two isolates had high MIC value for Itraconazole and three isolates produced biofilm.

Antifungal Susceptibility Profiles and Resistance Mechanisms of Clinical Diutina catenulata Isolates With High MIC Values.

Diutina catenulata (Candida catenulata) is an ascomycete yeast species widely used in environmental and industrial research and capable of causing infections in humans and animals. At present, there are only a few studies on D. catenulata, and further research is required for its more in-depth characterization and analysis. Eleven strains of D. catenulata collected from China Hospital Invasive Fungal Surveillance Net (CHIF-NET) and the CHIF-NET North China Program were identified using matrix-assisted laser desorption ionization–time of flight mass spectrometry and internal transcribed spacer sequencing. The antifungal susceptibility of the Diutina catenulata strains was tested using the Clinical and Laboratory Standards Institute broth microdilution method and Sensititre YeastOne™. Furthermore, ERG11 and FKS1 were sequenced to determine any mutations related to azole and echinocandin resistance in D. catenulata. All isolates exhibited low minimum inhibitory concentration (MIC) values for itraconazole (0.06–0.12 μg/ml), posaconazole (0.06–0.12 μg/ml), amphotericin B (0.25–1 μg/ml), and 5-flucytosine (range, <0.06–0.12 μg/ml), whereas four isolates showed high MICs (≥4 μg/ml) for echinocandins. Strains with high MIC values for azoles showed common ERG11 mutations, namely, F126L/K143R. In addition, L139R mutations may be linked to high MICs of fluconazole. Two amino acid alterations reported to correspond to high MIC values of echinocandin, namely, F621I (F641) and S625L (S645), were found in the hot spot 1 region of FKS1. In addition, one new amino acid alteration, I1348S (I1368), was found outside of the FKS1 hot spot 2 region, and its contribution to echinocandin resistance requires future investigation. Diutina catenulata mainly infects patients with a weak immune system, and the high MIC values for various antifungals exhibited by these isolates may represent a challenge to clinical treatment.

Virulence and in vitro antifungal susceptibility of Candida albicans and Candida catenulata from laying hens

In spite of evidence that domestic and wild birds may act as carriers of human pathogenic fungi, data on the role of laying hens as reservoirs of drug resistant and virulent yeasts is lacking. Here, we assess several virulence factors (phospholipase and haemolysin activity) and the antifungal susceptibility profiles of 84 Candida albicans and 17 Candida catenulata strains isolated from cloacae (group A), faeces (group B) and eggs (group C) of laying hens. Of these strains, 95% C. albicans and 23% C. catenulata strains displayed phospholipase and haemolytic activities. For C. albicans, the highest values of phospholipase (Pz = 0.62) and haemolytic activities (Hz = 0.49) were recorded among the strains from group C whilst for C. catenulata (Pz = 0.54; Hz = 0.49) among those from group A. High minimum inhibitory concentration (MIC) values for azoles and amphotericin B (AmB) were recorded irrespective of their sources in all C. albicans strains. A total of 22 C. albicans strains were multidrug resistant, displaying resistance to fluconazole, itraconazole (ITZ), voriconazole (VOR) and posaconazole (POS). All C. catenulata strains from group C were resistant to ITZ, POS, micafungin and anidulafungin and susceptible to AmB. In this study, C. albicans and C. catenulata isolated from the cloacae, faeces and eggs of laying hens produced phospholipase and haemolysin and might be multidrug resistant. In the environment (faeces) or in eggs, C. albicans and C. catenulata strains might acquire pathogenic virulence traits and/or show multidrug resistance profiles. Based on these results, breeding and handling of laying hens and/or eggs may have implications for human and animal health.

An investigation of tap water quality in Kuantan, Pahang, Malaysia

Assessment of the quality of tap water at Kuantan area of Pahang, Malaysia was investigated. The parameters analyzed were total coliform, Escherichia coli, pH, total hardness, sulfate, and selected heavy metal based on drinking water quality standard Malaysia and WHO. The results showed that the fungi in the tap water in Kuantan area in different concentrations were Aspergillus sp., Rhodotorula mucilaginosa, Penicillium citrinum, Cladosporium cladosporioides, Cerrena sp., Aspergillus aculeatus, A. flavus, Cryptococcus sp., Cladosporium perangustum, Purpureocillium lilacinum and Candida catenulata. The residual free chlorine varied from 0.05 to 1.97 mg/l.

Inulinase Production from Plant Materials by some Local Yeast Strains

Four inulinolytic yeast isolates were isolated and identified by molecular methods. They were belonged to Candida catenulata, Sarocladium kiliense, Galactomyces candidum and Scopulariopsis brevicaulis. The production of inulinase by the previous isolates through, 72h was done on two media using jerusalem artichoke tubers, garlic bulbs, dahlia tubers and chicory roots as natural sources of inulin. The highest values of the produced inulinase were obtained on Bharathi et al. (2011) medium after 48h of incubation. Jerusalem artichoke proved to be the best inulin source for enzyme production by Scopulariopsis brevicaulis (38.22 µg/ml), followed by dahlia (32.45 µg/ml). The best substrate for inulinase production by Sarocladium kiliense was dahlia (29.21 µg/ml) followed by garlic (28.65 µg/ml). As for Galactomyces candidum the maximum enzyme production was obtained using jerusalem artichoke (34.96 µg/ml) followed by garlic (31.84 µg/ml). The best material for inulinase production by Candida catenulate (34.15 µg/ml) was dahlia, followed by garlic (31.40 µg/ml). It can be concluded that inulin containing plant materials could be employed as a carbon source for inulinase production, it offer advantage in comparison to purified substrate because it have low cost and high productivity.

Results of the use of micafungin in newborns

Invasive candidiasis is a common and serious infection in premature newborns. Preventing and treating fungal infections is very important to improve the prognosis of premature infants. Fluconazole and amphotericin B are used as the first choice in the treatment of invasive fungal infections of the newborns. In some cases, fluconazole and amphotericin B cannot be used due to nephrotoxicity, hepatotoxicity or resistant strains. Micafungin, which is among recently developed echinocandins, is the drug of choice in these cases. The use of micafungin in newborns is new and there is a limited experience about the effect of high dose usage in the central nervous system. The aim of this study was to evaluate the electronic files of patients who used micafungin for the treatment of culture-proven or possible invasive fungal infection during their hospital stay in the neonatal intensive care unit during a 24-month period (2016-2017) in the third-level intensive care unit. A total of 15 patients (10 premature and 5 term babies) were included in the study. The mean birth weight of the patients was 1732 ± 999 g and the mean gestational age was 32.2 ± 5.8 weeks. All patients had long-term intensive care and increased risk of invasive candidiasis infection. Central venous catheterization and multiple antibiotics usage were the most common risk factors in these patients. The other risk factors included intubation, total parenteral nutritional use and surgical procedure application. Candida species were isolated from the cultures of four patients. Candida species isolated from patients were Candida albicans, Candida glabrata, Candida catenulata, Candida parapsilosis. The mean time for onset of micafungin was 29.9 ± 16.6 days. Mean duration of micafungin therapy was 22.4 ± 11.2 days. Eight patients received amphotericin B, three patients received fluconazole therapy and four patients did not receive any antifungal therapy before the onset of micafungin. None of these patients had an abnormal kidney or liver function tests due to micafungin use. As a conclusion, high dose (10 mg/kg/day) micafungin is a safe and effective treatment choice both in the treatment of neonatal culture proven or probable invasive candida infections that were caused by refractory Candida strains, and in the case of nephrotoxicity and hepatotoxicity.

The Prevalence of Yeast and Characteristics of the Isolates from the Digestive Tract of Clinically Healthy Turkeys.

This study was undertaken to explore the issue of yeast species prevalence in colonizing the gastrointestinal tract of healthy turkeys. The samples were collected from the beak cavity, crop, and cloaca of 5-wk-old turkeys, cultured and classified using morphological, biochemical, and genetic analysis based on ITS1-5.8rRNA-ITS2 fragment sequencing. Out of all the samples, 12.4% were yeast positive. The highest number of strains, 50% of the total collected, were isolated from the crop, with 30.8% coming from the beak cavity and 19.2% from the cloaca. The most frequently isolated yeast belonged to Candida species (88.5%), followed by Trichosporon (7.7%) and Rhodotorula (3.8%). The most prevalent species was Candida catenulata (30.7%), followed by Candida albicans (21.7%), Candida palmioleophila (17.4%), Candida rugosa (17.4%), and Candida glabrata (8.7%). The present study, showing the prevalence of yeast species of the gastrointestinal tract, is a stepping stone to investigating the physiological mycobiota of turkeys' gastrointestinal tract.

Genome analysis of the yeast Diutina catenulata, a member of the Debaryomycetaceae/Metschnikowiaceae (CTG-Ser) clade.

Diutina catenulata (Candida catenulata) is an ascomycetous yeast that has been isolated from humans, animals and environmental sources. The species is a contaminant of dairy products, and has been linked to superficial and invasive infections in both humans and animals. Previous phylogenetic analyses have assigned the species to the Saccharomycetales, but failed to identify its specific clade. Here, we report the genome sequence of an environmental isolate of D. catenulata. Examination of the tRNA repertoire and coding potential of this species shows that it translates the CUG codon as serine and not leucine. In addition, two phylogenetic analyses using 204 ubiquitous gene family alignments and 3,826 single-copy genes both confirm the placement of the species in the Debaryomycetaceae/Metschnikowiaceae, or CTG-Ser clade. The sequenced isolate contains an MTLα idiomorph. However, unlike most MTL loci in related species, poly (A) polymerase (PAP) is not adjacent to MTLα1.

Yeasts isolated from cloacal swabs, feces, and eggs of laying hens.

Domestic and wild birds may act as carriers of human pathogenic fungi, although the role of laying hens in spreading yeasts has never been investigated. We evaluated the presence of yeasts in the cloaca (Group I, n = 364), feces (Group II, n = 96), and eggs (Group III, n = 270) of laying hens. The occurrence and the population size of yeasts on the eggshell, as well as in the yolks and albumens, were assessed at the oviposition time and during storage of eggs at 22 ± 1°C and 4 ± 1°C. A statistically higher prevalence and population size of yeasts were recorded in Group I (49.7% and 1.3 × 104 cfu/ml) and II (63.8% and 2.8 × 105 cfu/ml) than in Group III (20.7% and 19.9 cfu/ml). Candida catenulata and Candida albicans were the most frequent species isolated. Candida famata and Trichosporon asteroides were isolated only from the eggshells, whereas Candida catenulata was also isolated from yolks and albumens. During storage, the yeast population size on the shell decreased (from 37.5 to 8.5 cfu/ml) in eggs at 22 ± 1°C and increased (from 4.6 to 35.3 cfu/ml) at 4 ± 1°C. The laying hens harbor potentially pathogenic yeasts in their gastrointestinal tract and are prone to disseminating them in the environment through the feces and eggs. Eggshell contamination might occur during the passage through the cloaca or following deposition whereas yolk and albumen contamination might depend on yeast density on eggshell.