Yeast Flora Research Articles

A PERSONALIZED APPROACH TO DIAGNOSIS OF DEMODECOSIS

Purpose. Improving the diagnosis of demodicosis based on a personalized approach to choosing a method for collecting material, clinical manifestations for extracting ticks and assessing the degree of tick infestation. Materials and methods. The results of an examination of 57 patients with clinically and laboratory confirmed demodicosis are presented. The exclusion criteria were patients with acne, rosacea, perioral dermatitis. Clinical manifestations were assessed by dermatoscopy. The material was collected for microscopic detection of mites using 2 traditional and 3 proprietary methods. Microscopy was also used to identify bacterial flora in pustules and yeast flora in scrapings of the epidermis. Results. A comparative analysis of the effectiveness of 4 diagnostic methods showed the priority of comedone extraction: 5 or more mites were found from an area of 0.5 cm2 in 96.5% of patients. The occurrence and abundance of mites were highest in the material from follicular papules with “spikes” (74.5%, 4.9±1.1 specimens) and typical follicular papules (56.3% and 6.1±1.7). When the disease duration was more than 6 months, the phenomenon of “strands of vellus hair“ was detected in the contents of follicles at the same time with mites (5–17 specimens). Analysis of the contents of the pustules made it possible to prove the antagonism between the pyogenic flora and mites of the genus Demodex.

Isolation and investigation of external reproduction tract mycoflora in healthy male cats.

Various infectious agents can infect the male reproductive system. The aims of this study were to provide current data on fungal and yeast flora of the external organs of reproductive system of male short hair cats including penis and prepuce. In total 28 samples were taken from external genital system of male stray cats using sterilised cotton swabs. Samples were taken based on the absence of any reproductive complications using physical examinations. The samples were transferred to sterilised Stuart transport media and were then incubated in the Sabouraud dextrose agar with chloramphenicol at 32°C for 48h. The identification of fungi and yeasts was confirmed by germ tube formation test, CHROM agar, urease testing and Corn meal agar medium with Tween 80. Fungal agents were isolated from 7 (25%) out of 28 male stray cats. Fungal isolates were obtained from the penis and prepuce of 4 (36%) and 7 (100%) male cats, respectively. The most commonly recovered species samples were Candida krusei (3.75%) and Penicillum spp. (6.86%) from the penis and prepuce of the cats, respectively. The external organs of male reproduction of cats were infected with 2-4 different fungal agents. Only 5 (45%) cats were infected with one fungus; however, in 6 (55%) cats, mixed fungal infections were isolated. Cats 3-4 years old had the highest fungal contamination in the prepuce region (4/7), while the penis at this age had the least contamination (1/4). It is concluded that the external reproduction organs of male cats could be infected by different fungal agents.

BEER PRODUCTION BY FERMENTATION PROCESS: A REVIEW

Beer is an age-old alcoholic, recreational beverage popular worldwide. It is produced by the process of brewing which involves the enzymatic fermentation of the mixture of water, starch, and hops by yeast in a specific condition. Production of beer from cereal grains involved several steps including grain treatment, malting, mashing, lautering, filtration, fermentation, maturation, finishing, and packaging. The brewing process has a marked effect on the quality, taste, aroma, consistency and alcoholic content. Several types of beers with distinct characteristics can be produced by varying the brewing conditions and yeast flora. Apart from psychoactive affects beer can have several medicinal benefits when consumed in moderation. This review presents a detailed understanding of the several steps for enhancing the brewing process for commercial beer production with desirable quality and flavour. The review also highlights current research progress in the innovative methods and techniques adapted for the cost-effective production of beer, including key advances, potential applications and limitations. Therefore, keeping in view the demands of beer in human daily life, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost-effective beer production.

Evolution of yeast biodiversity and volatile compounds during spontaneous fermentation of ‘Karasakiz’ grapes from different regions over two consecutive vintages

Spontaneous fermentation may produce complex and unique wines with geographical designations due to the region-specific yeast flora and variations in must characteristics. The current study focused on the yeast diversity and changes in volatile compounds during the spontaneous fermentation of ‘Karasakız’ grapes from three sub-regions of Çanakkale province, Turkey for two vintages (2019 and 2020). This is the first study on the diversity of autochthonous yeasts during wine fermentation of ‘Karasakız’ variety. In the present work, the strains belong to Hanseniaspora uvarum, Starmerella bacillaris, Pichia terricola, Metschnikowia pulcherrima and Zygoascus hellenicus by PCR-RFLP of the ITS region were identified . A total of 272 isolates were identified as S. cerevisiae. Yeast population and diversity changed related to the sub-region and the vintages. However, H. uvarum and S. bacillaris were common denominators of three regions evaluated. H. uvarum was dominant in the early stages of the fermentation, except for Bozcaada 2019 vintage. Bozcaada region also exhibited higher S. cerevisiae strain diversity compared to other regions. 1-Hexanol and 1-octanol gradually decreased during the fermentation of ‘Karasakız’ grapes, while the concentration of isoamyl alcohol, phenylethyl alcohol and ester compounds increased by the fermentation but with some fluctuation.

Genetic Diversity of Candida spp. Isolates Colonizing Twins and Their Family Members.

A wide range of options for studying Candida species are available through genetic methods. Twins, particularly monozygotic ones and their families may be fitting subjects for studying those microorganisms. The question is: How specific can yeast flora be in an individual? The study aimed to analyze the strain relatedness among commensal yeasts isolated from various parts of the bodies of healthy people and to compare correlations between the genotypes of the isolates. Yeasts were isolated from 63 twins and their family members (n = 25) from the oral cavity, anus, interdigital space and navel. After species identification, Candida albicans (n = 139), C. parapsilosis (n = 39), C. guilliermondii (n = 25), C. dubliniensis (n = 11) and C. krusei (n = 9) isolates were analyzed using the random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) optimization method. The similarities between the strains were calculated based on the Dice (Sab) coefficient and are displayed graphically as dendrograms. Using cluster analysis, the following relatedness was distinguished: 13 genotypes and three unique (Un) patterns among C. albicans; 10 genotypes and four Un patterns among C. parapsilosis; three genotypes and one Un pattern among C. guilliermondii and C. dubliniensis; and three genotypes among C. krusei isolates. The presence of identical, similar or both genotypes among the strains isolated from family members shows the transmission of yeasts between ontocenoses in the same person and between individuals. The similarity between the genotypes of C. albicans, C. guilliermondii, C. dubliniensis and C. krusei was more remarkable than between the genotypes of C. parapsilosis in the strains isolated from ontocenoses of the same individual and their family members. The degrees of genetic similarity between Candida spp. strains isolated from monozygotic twins and those obtained from their relatives did not differ.

Comparative analysis of hop starter cultures for whole grain bread

Recently, the tradition of baking sourdough bread has been revived all over the world. The Industrial Revolution has radically changed the technology of making bakery products. Information about the dangers of high-speed yeast is rapidly spreading, which makes the consumer think about the benefits of the products consumed. Technologists of the baking industry, in turn, this forces them to return to their origins and develop recipes for healthy traditional bread according to international standards. During the research, three samples of starter cultures for whole-grain bread based on decoctions from hop cones were developed. Hop cones contribute to obtaining an optimal starter culture and the successful reproduction of yeast flora in it. They help to activate the fermentation process. They contain a large amount of antioxidants, which increases the shelf life of bread and allows it to be enriched. A comparative analysis of the activity of yeast cells in the hop ferments being developed using the Goryaev chamber was carried out. Counting of yeast cells showed that in the samples of hop starter cultures No. 1 and No. 2, their number differs slightly and amounts to 6.75·108 cl/cm3 and 6.25·108 cl/cm3, respectively. In sample No. 3, the content of yeast cells turned out to be slightly less than in the others. This indicates that in the production of bread with the use of this hop starter, the fermentation operation will take a longer time. The analysis of the technological process of preparing starter cultures of samples No. 2 and No. 3 showed that in sample No. 3 it is quite time-consuming and time-consuming. The results obtained on the development of samples of hop starter cultures indicate the possibility of their application in the technology of whole grain bread products.

Technological characterisation and probiotic traits of yeasts isolated from Sha'a, a Cameroonian maize-based traditional fermented beverage

The current trend in starter selection is to combine both technological and probiotic properties to standardise and make functional artisanal fermented beverages such as Sha'a whose properties are very variable due to the lack of a known starter. The objective of this work was to study technological and probiotic properties of yeasts isolated from Sha'a sold in Bamenda, Bafoussam, Bonabérie, Dschang, Foumbot, Mbouda and Njombé (Cameroon). The isolated yeasts were studied for their ability to produce CO2 from glucose, to grow in the presence of 8% ethanol, 20% glucose and pH 3, to assimilate maltose and to produce ethanol. Then, the survival of the pre-selected isolates was assessed in simulated gastric (pH 2 and 3) and intestinal juices, followed by self-aggregation, co-aggregation, hydrophobicity, haemolysin, gelatinase, biogenic amine production, antibiotic and antifungal susceptibility, bile salt hydrolase and antiradical activity. The selected isolates were identified by sequencing the 5.8S/28S rRNA gene. From the 98 isolates obtained, 66 produced CO2 from glucose and 16 were then selected for their ability to grow in the presence of 8% ethanol, 20% glucose, pH 3 and maltose. The overall survival of isolates ranged from 4.12 ± 1.63 to 104.25 ± 0.19% (LT16) and from 0.56 ± 0.20 to 96.74 ± 1.60% (LT66) at pH 3 and pH 2 respectively. All of them have remarkable surface hydrophobicity properties. Based on principal component analysis, 5 isolates were selected as the best. However, only 3 of them, LT16 (the most promising), LT25 identified as Saccharomyces cerevisiae and LT80 as Nakaseomyces delphensis, do not produce a virulence factor. The latter can deconjugate bile salts with a maximum percentage of 60.54 ± 0.12% (LT16) and the highest inhibition of DPPH° radicals was 55.94 ± 1.14% (LT25). In summary, the yeast flora of Sha'a contains yeasts capable of fermenting and producing ethanol while producing bioactive compounds that would benefit the consumer.

Novel pulsed infrared radiation: Effect on microbial, chemical and sensory properties of saffron (Crocus sativus L.).

In this study, the effect of pulsed infrared (PIR) irradiation on saffron microbial, chemical and sensory properties were evaluated. The PIR power (250, 350 and 450 W), the distance of sample with irradiation source (10, 20 and 30 cm), irradiation time (0-20 min) and PIR pulse (1, 2 and 3 pulse/s) were investigated. Decontamination of total bacteria and total mould and yeast flora and microbial inactivation kinetics were determined. Saffron quality by FTIR and HPLC and sensory attributes were also measured. The highest reduction of the total bacterial count (2.203 log10 CFU per g) and total mould and yeast counts (2.194 log10 CFU per g) were obtained in Sargol Negin saffron at 350 W PIR power, 10cm distance, 1.5min treatment time and 3 pulse/s. The Double Weibull model is the best-fit model for the prediction of the microbial population. Until now, there have been no reports of application for PIR in food processing and decontamination. According to the results, it can be concluded that PIR can be used as a safe method of saffron processing. Utilization of a proper decontamination method for spices especially saffron as the most expensive agricultural product is challengeable. It is recommended to use the PIR method for food processing because due to the reduction of microbial population, it can maintain foodstuff quality at an acceptable level.

Molecular identification and technological properties of yeasts isolated from spontaneously fermented cassava waste pulp

The aim of this work was to report on molecular identification and technological properties of the yeast flora isolated from spontaneously fermented cassava waste pulp. This was done with a view of obtaining yeast strains that could be used as a starter culture for the fermentation of cassava waste pulp. Molecular identification was based on the nucleotide sequence of the ITS region of the genomic DNA of the yeast isolates while the technological properties evaluated include linamarase (U/mL), gelatinase, and haemolytic activity; growth at pH 2.5 and tolerance to 2 % bile salt. All the representative five isolated yeasts were identified as Geotrichum silvicola KLP04 – KLP08. The isolates exhibited linamarase activity ranging between 3.3 and 4.2 with strain KLP04 having the highest value and strain KLP05 the least. None of the isolates demonstrated gelatinase and haemolytic activity except strain KLP08 which was partially haemolytic. All the examined yeasts exhibited good growth at pH 2.5, with strain KLP08 having the highest viable counts of 4.1 log10cfu/ml and strain KLP04 the least value of 3.5 log10cfu/ml after 72 h of growth. All the identified yeasts showed strain-specific tolerance to 2% bile salt with strain KLP04 having the highest viable count of 4.3 log10cfu/ml and strain KLP08 the least value of 2.2 log10cfu/ml at the end of 72 h of incubation. Based on all the examined technological properties, Candida silvicola KLP04 strain had the highest potential to be considered for starter culture for the fermentation of cassava waste pulp.

OENOLOGICAL CHARACTERISTICS AND VINIFICATION RESULTS OF THE YEAST OF MALAGOUSIA GRAPE ISOLATED IN GREECE

Malagousia grapes, selected from 5 different PGI Greek zones, in 3 different growing seasons (2018-2019, 2019-2020, 2020-2021) were collected in the stage of technological maturity. Quantity of 25 Kg grapes fermented spontaneously in 30 l thermo regulated stain steel tanks, produced white wine. The indigenous yeast flora, isolated at three phases of the alcoholic fermentations, was studied. Different yeast species were isolated, purified and characterized. The restriction fragment length polymorphism of PCR-amplified fragments from the rDNA gene cluster (PCR RFLP of rDNA) has been used for the differentiation of yeast species. The standard identification procedure has been performed on representative strains that shared identical RFLP profiles showed great diversity of the yeast population. Including grape berries, must and fermented must, the following yeast species were identified: a number of Pichia and Candida species, Kloeckera apiculata, Cryptococcus curvatus, Metschnikowia pulcherrima, Kluyveromyces, as well as Saccharomyces cerevisiae and Saccharomyces stranieri. We performed microscopic, macroscopic and carbon assimilation tests by API 32C standardized system, biotechnological testing and hydrolase profiling obtained by the API-ZYM system. The most significant findings in population dynamics of yeasts in the spontaneous fermentations were bigger diversity of different species of Non- Saccharomyces in organic grapes and almost complete absence of non-Saccharomyces species, at least at grapes and at the beginning of the alcoholic fermentations at conventionally cultivated grapes, from all the examined PGI zones in all the three years of the study. The use and enhancement of indigenous yeasts is an increasing trend. Rapid identification of the yeast population is necessary for successful monitoring of the fermentation process and for obtaining a good wine quality as well as contributing to the optimization of Greek wine production.

Molecular Investigation of Diversity Normal Yeast Flora in Cow Raw Milk Industrial Farms of Tehran Province and Alborz

Molecular Investigation of Diversity Normal Yeast Flora in Cow Raw Milk Industrial Farms of Tehran Province and Alborz

Antifungal activity of Saccharomyces cerevisiae and assessment of ochratoxigenic load on currants by means of Real Time PCR

Currants are prone to contamination by ochratoxin during cultivation, processing and storage conditions. Saccharomyces cerevisiae is considered to be among the main species of grape yeast flora able to control antagonistic fungi. In this study, the potential of S. cerevisiae Y33 was investigated to inhibit the growth of several fungal species indigenous to the microbiota of grapes. Moreover, the efficacy of this yeast species was investigated to inhibit OTA by toxin producing fungi both in vitro and in situ. For this purpose thirty-five different fungal species, belonging to the genera Aspergillus, Penicillium, Cladosporium, Fusarium and Alternaria interacted in vitro with S. cerevisiae on Malt Extract agar plates, stored at 25 °C for 14 days. Results showed that the highest OTA producer A. carbonarius F71 was inhibited more than 99% from day 7, in contrast to A. niger strains that presented enhanced OTA production at day 14 due to interaction with S. cerevisiae Y33. Additionally, the antifungal potential of the selected yeast was also studied in situ on currants subjected to different treatments and stored at 25 °C for 28 days. Microbiological analysis was undertaken for the enumeration of the bacterial and fungal flora, together with OTA determination at 7 and 21 days. To quantify A. carbonarius on all treated currant samples, molecular analysis with Real Time PCR was employed. A standard curve was prepared with A. carbonarius DNA. The efficiency of the curve was estimated to 10.416, the slope to −3.312 and the range of haploid genome that could be estimated was from 1.05 to 105∙105. The amount of A. carbonarius DNA in all treated currants samples, where the fungus was positively detected, ranged from as low as 0.08 to 562 ng DNA/g currants. The antifungal activity of S. cerevisiae Y33 was observed in all studied cases, causing inhibition of fungal growth and OTA production.

Microbiological characteristics and identification of yeast microbiota of traditional mouldy civil cheese

Investigation of the traditional cheeses and bringing them to the industry contributes to the development of dairy technology in terms of quality and diversity. For this purpose, traditional Turkish mouldy Civil cheese, which has a rich microbial diversity and is lovingly consumed, was studied and its yeast flora revealed. Samples were evaluated in terms of aerobic plate count, psychrotrophic bacteria, proteolytic bacteria, yeast, mould, coliform, enterococci, presumptive lactobacilli, presumptive lactococci, Staphylococcus aureus and Enterobacteriaceae counts. Seventy isolates were characterised by RAPD-PCR with M13 primer. Six diverse species were detected: Yarrowia lipolytica, Kluyveromyces marxianus, Pichia membranifaciens, Debaryomyces hansenii, Pichia fermentans and Candida zeylanoides. As a result, yeast diversity in mouldy Civil cheese may have an important role on development of characteristic blue cheese flavour and selected yeast strains could be used as adjunct culture to improve the quality of the final product.

Reduction of Aflatoxins and Microorganisms in the Koura-Koura Produced in Burkina Faso with Spices and Aromatic Leaves

Koura-koura is a product resulting from the processing of peanut. This study consisted of producing koura-koura with garlic, pepper, ginger and mint to reduce aflatoxins and microorganisms. The objective of this work is the decontamination of koura-koura with spices and aromatic leaves. Aflatoxin determination was performed by HPLC and microbiological analyses were carried out according to standard methods. A total of 18 samples were analyzed, including 3 peanut samples, 2 peanut paste samples, 1 koura-koura control sample, and 12 samples of koura-koura spices and aromatic leaves. Total aflatoxin B1, B2, and aflatoxin levels in the samples ranged from 0.58±0.49 μg/kg to 3.66±0.10 μg/kg; 2.23±0.41 μg/kg to 14.02±0.88 μg/kg; 2.87±0.20 μg/kg to 17.75±0.58 μg/kg, respectively. Aflatoxins G1 and G2 were not detected in all samples. The total mesophilic aerobic flora (TMAF) ranged from 1.60±1.57 x101 CFU/g to 4.50±1.28 x105 CFU/g and the yeast and mould flora ranged from 1.80 ± 1.68 x101 CFU/g to 2.80±0.74 x101 CFU/g. No samples were contaminated with thermo-tolerant coliforms and total coliforms were present in a single sample (1.30 ± 1.64 x 101 CFU/g). The results of the study on the reduction of aflatoxins and microorganisms in koura-koura with spices and aromatic leaves contribute significantly to food safety.

Проблемы диагностики и лечения бактериального вагиноза в активном репродуктивном возрасте

Aim: to assess the efficacy and safety of vaginal capsules containing metronidazole 100 mg and myconazole nitrate 100 mg in women with bacterial vaginosis (including recurrent vaginosis). Patients and Methods: 62 women were enrolled. Group 1 included 32 women with firstly diagnosed bacterial vaginosis. Group 2 included 30 women with recurrent bacterial vaginosis. Vaginal capsules containing 100 mg of metronidazole and 100 mg of miconazole nitrate (Gynocaps) or Gynocaps plus peroral metronidazole 250 mg twice daily (combined therapy) were prescribed. Group 1 and group 2 were divided into subgroups, i.e., 1A (n=20) and 1B (n=12), 2A (n=18) and 2B (n=12), based on treatment (monotherapy or combined therapy, respectively). Treatment efficacy was assessed 1 month and 12 months after completing treatment. Results: the major symptom in both groups was off-white vaginal discharge. Diffuse vulvar redness was more common in group 1 while petechiae were more common in group 2 (p<0.05). Lactobacillus spp. counts were reduced in all women, mixed infections were predominant. In group 2, significantly higher counts of anaerobic and yeast flora compared to group 1 were reported (p<0.05). In group 1, no significant differences in the improvement of clinical signs after both treatment regimens were reported. Meanwhile, in group 2, clinical signs improved more rapidly after combined treatment. However, combined treatment was associated with adverse effects. A reduction in the total bacterial mass and logarithmic growth of anaerobic microflora was observed irrespective of the treatment regimen. No recurrences of bacterial vaginosis were reported. Conclusions: a 10-day treatment course of combined vaginal capsules containing metronidazole 100 mg and miconazole nitrate 100 mg improves clinical signs, eliminates complaints, and improves vaginal microflora owing to Lactobacillus growth without adverse reactions. In recurrent vaginosis, this agent should be used in combination with antibiotics. KEYWORDS: bacterial vaginosis, active reproductive age, metronidazole, miconazole nitrate, Lactobacillus. FOR CITATION: Chebotareva Yu.Yu. Diagnosis and treatment of bacterial vaginosis during active reproductive age. Russian Journal of Woman and Child Health. 2021;4(3):218–224 (in Russ.). DOI: 10.32364/2618-8430-2021-4-3-218-224.

Diversity and enzymatic profiles of indigenous yeasts isolated from three types of palm wines produced in Côte d'Ivoire.

To investigate the genotypic diversity and enzymatic activity of yeast flora isolated from spontaneous fermenting saps of various palm trees (Borassus aethiopum, Raphia hookeri, Elaeis guineensis) tapped for palm wines. PCR-restriction fragment length polymorphism of ITS-5.8S rDNA combined to 26S rRNA gene and/or the partial ACT1 gene sequencing were applied for yeast characterization, and their enzymatic profiles assessed by using API ZYM kits. Thirteen genera and 23 species were identified, with the highest diversity (14 species) in raffia wine. Saccharomyces cerevisiae was dominant and common to all palm wines. Some potentially pathogenic yeasts were also isolated. The majority of tested strains displayed high amylo-peptidase, phosphatase, β-glucosidase and α-glucosidase activities and esterase activity. Diverse yeast species colonized palm wines, among which some were related to a specific type of wine and the majority of them have the ability to digest starch, sugar, protein or lipid. This study is a first step in understanding the significance of indigenous yeast flora of palm wines from Côte d'Ivoire. This knowledge is important as a tool for establishing new indigenous yeast collection; which could be used for the product quality improvement and as enzyme sources for biotechnological purposes.

Prospects of studies on the yeast flora of sturgeons for monitoring of their state in aquaculture

Seasonal changes in abundance and species composition of the yeast flora from organs of juvenile sturgeons were traced during their growing in the warm-water ponds of Luchegorsk Research Station of the Pacific Fish. Res. Centre (TINRO) in 2008-2009. The fungal community of the sturgeons was represented by whey, brewers, and wine yeasts, mostly with probiotic properties. Naganishia albida, Papiliotrema laurentii, Saccharomyces cerevisiae, Trichomonascus ciferrii , and fungi of the genus Candida were found in the intestines and gills of kaluga and siberian sturgeon juveniles, but they came from the water and are usual for microflora of cages for fish cultivation. Cryptococcus neoformans and Ogataea angusta were found in the water only. Rhodotorula mucilaginosa , Cystobasidium minuta and fungi of the genus Hanseniaspora were associated with the sturgeon organs. Generally the yeast heterotrophic microbiota in the cages showed inhibitory effect against mould and enterobacteria. Colonization of the sturgeon mucous membranes by yeasts had seasonal dynamics that definitely affected on local immunity of the juveniles. Complete elimination of the yeasts from the sturgeon mucous membranes should be considered as a predictor of worsening of their physiological state and anti-epizootic measures are necessary in this case.

Diversity, in-vitro virulence traits and antifungal susceptibility pattern of gastrointestinal yeast flora of healthy poultry, Gallus gallus domesticus

BackgroundPoultry farming and consumption of poultry (Gallus gallus domesticus) meat and eggs are common gastronomical practices worldwide. Till now, a detailed understanding about the gut colonisation of Gallus gallus domesticus by yeasts and their virulence properties and drug resistance patterns in available literature remain sparse. This study was undertaken to explore this prevalent issue.ResultsA total of 103 specimens of fresh droppings of broiler chickens (commercial G domesticus) and domesticated chickens (domesticated G domesticus) were collected from the breeding sites. The isolates comprised of 29 (33%) Debaryozyma hansenii (Candida famata), 12 (13.6%) Sporothrix catenata (C. ciferrii), 10 (11.4%) C. albicans, 8 (9.1%) Diutnia catenulata (C. catenulate), 6 (6.8%) C. tropicalis, 3 (3.4%) Candida acidothermophilum (C. krusei), 2 (2.3%) C. pintolopesii, 1 (1.1%) C. parapsilosis, 9 (10.2%) Trichosporon spp. (T. moniliiforme, T. asahii), 4 (4.5%) Geotrichum candidum, 3 (3.4%) Cryptococcus macerans and 1 (1%) Cystobasidium minuta (Rhodotorula minuta). Virulence factors, measured among different yeast species, showed wide variability. Biofilm cells exhibited higher Minimum Inhibitory Concentration (MIC) values (μg/ml) than planktonic cells against all antifungal compounds tested: (fluconazole, 8–512 vs 0.031–16; amphotericin B, 0.5–64 vs 0.031–16; voriconazole 0.062–16 vs 0.062–8; caspofungin, 0.062–4 vs 0.031–1).ConclusionsThe present work extends the current understanding of in vitro virulence factors and antifungal susceptibility pattern of gastrointestinal yeast flora of G domesticus. More studies with advanced techniques are needed to quantify the risk of spread of these potential pathogens to environment and human.

Presence and distribution of yeasts in the reproductive tract in healthy female horses.

Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Longitudinal study. A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics and biochemical profiles. Yeast colonies were isolated from 60 (39.7%) of the 151 horses. The isolated yeasts belonged to nine genera, and included Candida spp. (53.2%), Cryptococcus spp. (12.2%), Saccharomyces spp. (10.5%), Geotrichum spp. (8.0%), Rhodotorula spp. (7.1%), Malassezia spp. (3.7%), Trichosporon spp. (2.6%), Kluyveromyces spp. (2.6%) and Sporothrix spp. (0.2%). Candida krusei (43.1%) was the most frequent Candida species isolated. There was a significant difference in prevalence between C. krusei and other Candida species (P<0.05). The vestibule contained more yeast isolates (48.0%) than the vagina (18.3%). The isolation of yeast colonies from multiparous females (76.8%) was significantly higher than from maiden mares (P<0.05). The study was limited by the difficulty of distinguishing between normal flora and potential pathogens. Candida spp., in particular C. krusei, represent important flora resident in the caudal reproductive tract in healthy female horses. This is particularly important in contexts that require the initiation of empirical treatment prior to the completion of culture results.

Genomics and Biochemistry of Saccharomyces cerevisiae Wine Yeast Strains.

Saccharomyces yeasts have been used for millennia for the production of beer, wine, bread, and other fermented products. Long-term "unconscious" selection and domestication led to the selection of hundreds of strains with desired production traits having significant phenotypic and genetic differences from their wild ancestors. This review summarizes the results of recent research in deciphering the genomes of wine Saccharomyces strains, the use of comparative genomics methods to study the mechanisms of yeast genome evolution under conditions of artificial selection, and the use of genomic and postgenomic approaches to identify the molecular nature of the important characteristics of commercial wine strains of Saccharomyces. Succinctly, data concerning metagenomics of microbial communities of grapes and wine and the dynamics of yeast and bacterial flora in the course of winemaking is provided. A separate section is devoted to an overview of the physiological, genetic, and biochemical features of sherry yeast strains used to produce biologically aged wines. The goal of the review is to convince the reader of the efficacy of new genomic and postgenomic technologies as tools for developing strategies for targeted selection and creation of new strains using "classical" and modern techniques for improving winemaking technology.