جستجوی مقالات مرتبط با کلیدواژه « yeast » در نشریات گروه « پزشکی »

For phagocytosis measurement, 5×105 macrophages were seeded in a 12-well plate. 20 ng/ml LPS was added to cells to induce the M1 phenotype. After 24h the medium was changed. A suspension of heat-killed baker’s yeast was prepared at 108 particles per ml in DMEM medium. The yeast suspension was added to macrophages at a ratio of 1:10 (macrophage: yeast). Macrophages were allowed for 60 minutes to phagocyte the particles at 37°C. To remove the free yeasts, the well was washed with PBS. The phagocytosis was observed using an inverted microscope.

Recently, the market demand for biopharmaceuticals and nutraceuticals has increased. Consequently, high-volume production strategies have also drawn a lot of attention. The invention and development of recombinant DNA technology, using various hosts from bacteria to mammalian cells, have led to the industrial-scale manufacture of many valuable pharmaceutical products. Among the hosts, yeasts have a special place due to their numerous benefits. The present study deals with commercial yeast-derived biopharmaceuticals and laboratory-scale yeast-extracted nutraceuticals. It represents the biotechnological potential of yeasts to meet the market's needs in this area. Besides, considering the COVID-19 pandemic, the applications of yeast hosts for the clinical management of this disease have been briefly discussed.Recently, the market demand for biopharmaceuticals and nutraceuticals has increased. Consequently, high-volume production strategies have also drawn a lot of attention. The invention and development of recombinant DNA technology, using various hosts from bacteria to mammalian cells, have led to the industrial-scale manufacture of many valuable pharmaceutical products. Among the hosts, yeasts have a special place due to their numerous benefits. The present study deals with commercial yeast-derived biopharmaceuticals and laboratory-scale yeast-extracted nutraceuticals. It represents the biotechnological potential of yeasts to meet the market's needs in this area. Besides, considering the COVID-19 pandemic, the applications of yeast hosts for the clinical management of this disease have been briefly discussed.

Candidemia is known as an invasive fungal infection with high mortality. The prevalence of candidemia in intensive care unit (ICU) patients is more than in other hospital wards. Early diagnosis of candidemia in these patients is essential for disease management.

This study included 250 patients suspected of candidemia. Blood samples were taken from patients and incubated. The fungal isolates were identified by PCR-RFLP method using MSP I restriction enzyme. Demographic characteristics, risk factors, underlying diseases, and laboratory analysis results were mined in this study.

In total, 22 blood samples were identified as positive for Candida yeasts in culture. The most common underlying diseases in these patients were heart disease and hypertension (36.4%). Candida albicans with 12 cases (54.5%) was the most isolated species, followed by C. parapsilosis (n=5, 22.7%), C. glabrata (n=4, 18.2%), and C. tropicalis (n=1, 4.5%) in descending order. Intravenous catheter use was recognized as the most common risk factor in patients with candidemia (77.3%), and after that, the use of mechanical ventilation (68.2%) and urinary catheter (40.9%) obtained the highest frequency. Furthermore, 17 patients were prescribed at least one antifungal drug, of which fluconazole was the most used (36.4%). The mortality rate in patients in this study was 63.6%. All C. albicans isolates were susceptible to antifungal agents but in nonalbicans Candida (NAC), drug resistance to fluconazole, voriconazole, and caspofungin were observed.

Although C. albicans was the most common fungal species in this study, the prevalence of NAC species was high. The increasing frequency of NAC species is a concern because they have different patterns of drug resistance. Recognition of risk factors in patients admitted to ICUs can help prevent candidemia or properly manage the disease.

Mentha is a genus from the family Lamiaceae, whose essential oils has long been used in different forms. This herbal plant has traditionally been used as an alternative medicine to treat candidiasis. So, it seems crucial to find new antimicrobials that have fewer side effects. In this study, we investigated the antifungal effects of Mentha aquatica L essential oil on pathogenic Candida spp. This descriptive cross-sectional study was performed on 137 Candida spp isolated from vulvovaginal candidiasis. These yeasts were confirmed by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Mentha aquatica L essential oil was prepared by water distillation and Clevenger apparatus. The antifungal activity of Mentha aquatica L essential oil and fluconazole versus Candida spp was determined by microbroth dilution method using CLSI guidelines. The most common species were identified that Candida albicans (63.5%), Candida glabrata (28.5%) and Candida krusei (8%), respectively. MIC50, MIC90 and geometric mean (GM) of fluconazole were 0.5 µg/ml, 4 µg/ml and 0.573 µg/ml and for Mentha aquatica L essential oil 1 µg/ml, 4 µg/ml and 0.931 µg/ml, respectively. The antifungal effect of fluconazole on Candida spp was higher than that of essential oil of plant. It seems that the inhibitory effect of essential oil of Mentha aquatica L has shown that this plant can be considered as a potential candidate for the development of antifungal drug in the treatment of vulvovaginal candidiasis.

Onychomycosis is caused by dermatophyte species, non- dermatophyte moulds (NDMs), and accounts for roughly 50% of all nail diseases. As the prevalence of onychomycosis is increasing, new epidemiologic documents may help with treatment and prevention. The present investigation aims to determine the epidemiological profile of onychomycosis in 2 mycology laboratories.

A cross-sectional study conducted during eight months (2019-2020) on 169 patients with positive nail mycology tests referred to two mycological laboratory centers affiliated with Tehran University of Medical Science. The nail clippings were examined by direct smear and culture. Also, molecular assays were performed if needed.

10% of nail lesions referred to Razi Hospital (RH), and 30% of nail lesions referred to TUMS mycology laboratory were positive. Middle age (40-60) suffer more from onychomycosis. Aspergillus flavus, Trichophyton mentagrophytes, and Candida albicans were the most common etiologic agents in each of the three main classes of fungi causing onychomycosis. Females were more infected. NDMs were the predominant etiologic agents, and toenails were the most common site of onychomycosis.

The pattern of etiologic agents and clinical signs of onychomycosis differs according to geographical region and age, so repeated epidemiological surveys of onychomycosis seem to be fundamental.

T Microorganisms cause many diseases for the human body such as urinary tract infection and, therefore, it is highly important to eliminate and control them. Bacterial resistance to different types of antibiotics was increased and it is necessary to find alternative agents to eliminate these microbes.

This study aimed was to evaluate the antimicrobial effect of different concentrations of titanium dioxide nanoparticles (TiO2 NPs) on some gram-positive bactria, gram-negative bacteria, and Candida albicans. TiO2 NPs were synthesized using the chemical methods, coated with carboxymethyl cellulose (CMC) and prepared in different concentrations (0.098, 0.196, 0.392, 0.784, 1.568, and 3.136 mg/mL). Eventually, a minimum inhibitory concentration (MIC) and a minimum biofilm inhibitory concentration (MBIC) were applied to investigate the effect of TiO2 NPs on microorganisms.

According to the study results, the MICs of TiO2 NPs were found to be 1.489, 1.208, and 1.166 mg/ mL for Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae as the Gram-negative bacteria, respectively; and they were discovered to be 0.512, 0.830, and 0.707 mg/mL for Streptococcus pneumoniae, Staphylococcus aureus, and Staphylococcus epidermidis as the Gram-positive bacteria, respectively. As for C. albicans, as the yeast strain, MIC was 0.253 mg/ mL. The MBIC of more than 90% of TiO2 NPs was 6.25 mg/mL for both Gram-negative and Gram-positive bacterial types and 1.562 mg/mL for C. albicans.

It was concluded that TiO2 NPs were effective antimicrobial agents for Gram-positive bacteria, Gram-negative bacteria, and C. albicans, but their inhibitory effect on yeast was greater than that of bacteria.

The colonized microorganisms in the fish gastrointestinal (GI) tract have recently received particular attention as a probiotic. Therefore, we aimed to identify potential probiotic yeasts from the GI tract of the beluga (Huso huso). The fish were randomly caught from beluga-breeding ponds. The isolated yeast strains were investigated for some properties of probiotic potentials, including tolerance to acidity and bile salt (Oxgall). Yeast strains with probiotic potentials were identified to species level using polymerase chain reaction and sequencing the internal transcribed spacer regions of rDNA. Seventeen different yeast strains were isolated from the beluga's GI tract based on macroscopic and microscopic characteristics. Nine yeasts (52.9%) could tolerate acid (pH = 2) for up to 3 h. Among acid-resistant yeasts, four yeasts could tolerate bile salts for up to 8 h. By comparing the obtained sequences with reference sequences in GenBank, all strains were identified as Candida parapsilosis. Sequence data of each strain were assigned in GenBank under the accession numbers. Identifying the fungal microbiota of healthy fish and determining their probiotic prospects can help us use them in aquaculture. Further extensive studies are recommended to identify fungal-biota with probiotic potential in more fish species.

 Milk is a completely rich and complex environment suitable for different microorganisms including bacteria and Fungi. The majority of studies were conducted on milk-bacterial flora and aflatoxin-contaminations in dairy products; however, despite the importance of yeasts in usage as starter in the dairy industries and their effect on the taste of dairy products as well as in dairy probiotic characteristics, almost no information exist concerning fungal-flora in milk. So, the aim of this study was investigation on the raw milk yeast-microflora and it’s relation to the hygienic level and other characteristics of dairy farms. Existence of fungus were studied in defined raw milk samples and the diversity of isolated yeasts were examined.

Samples were collected within a period of one year (March 2016-March 2017) and evaluated based on Internal Transcribed Spacer (ITS-1-ITS-2) parts of rDNA. Isolated yeasts were identified using PCR-RFLP and Sequencing tests.

Total of 262 raw milk samples were collected from 14 farms in Tehran and Alborz provinces in Iran. About 66% of milk samples contained yeast microflora. The dominant isolated yeasts were characterized as: Candida globose, Geotrichum candidum, Pichia kudriavzevii, Tricosporon asahii, Pichia jadinii, Kluyveromyces marxianus, Magnusiomyces capitatus, Wickeihameilla pararugosa, and Candida inconspicua. Other candida species such as Candida parapsilosis, Candida tropicalis, and Candida glabrata were also isolated in a limited level.

Dominant yeast flora was identified in raw cow’s milk samples. The obtained results also indicated that fungal diversity varies from field to field. However, similarities in some isolated species have been revealed.

The presence of yeasts in the urine is not synonymous with urinary tract infectionsinceit can result insimple colonization or contamination. Regarding this, it is required to further clarify the epidemiological profile of funguria. Accordingly, the present study was conducted to establish the epidemiology of funguriainthe Mohammed VI Teaching Hospital of Oujda, Morocco.

This retrospective studywas conducted onall urine samples sent for cytobacteriological examination to amicrobiology laboratoryover a period of 28 months(i.e., from March 2016 to June 2018). After the removal of duplicates, the urinesampleswere treated according to the recommendations of the medical microbiology standards.

A total of15,165 urine sampleswerecollected. Urinary colonization accounted for 4.94% (n=749) of cases. The infections of the urinary tract accounted for 5.35% (n=811) of cases. Microbial isolates (n=1,669) in colonization and urinary tract infections were dominated by bacteria (93.47%, n=1,560). Furthermore, the yeasts accounted for 6.53% (n=109) of the isolates. Candidaalbicanswas isolated from56.88% (n=62) of funguriacases. Theriskfactors forfunguriain our series wereessentially old age, admission tointensive care unit, and broad-spectrum antibiotic therapy.

The current level of knowledge about the clinical situations leading tofunguriawith the improvement and popularization of efficient identification techniques for yeasts other than C. albicans should redress the epidemiology of funguria.This should allowtheknowledgeablesocieties to establish the rules of interpretingthecytobacteriological examination of the urine in case of funguria, as for bacteriuria.

The objective of this study is to test the toxicology of methanolic extract of Marrubium vulgare "MEMV" in rat and its efficiency in the treatment of systemic candidiasis.

First, forty (40) male rats "Wistar type" are used. Second, they are divided into four groups (10 rats /group) where the toxicological, microbiological and histological studies are applied. Later, the infection with 107 cells /ml of C. albicans and the curative treatment are applied by the daily administration with a gavage of 800 mg/kg of MEMV. Finally, the toxicology studies indicate that the dose of methanolic extract of Marrubium vulgare at 800 mg/kg of body weight is not harmful.

As a final result, the microbiological and histological analysis showed that the treatment with MEMV of rat colonized with 107 cells /ml of C. albicans limits the multiplication of the yeast in the intestine and colon of the colonized rat. The translocation of Candida albicans in liver, spleen and lungs in rat which is treated with 800 mg/kg after inoculation with C. albicans is significantly lower than in controls to seven post- infection days. However, we do not detect yeast in the kidneys and hearts of the infected treated groups and the infected untreated ones.

Our results suggest that MEMV limits the gastrointestinal colonization and dissemination of C.albicans in the other organs.

Sugar-rich foods are of the main components of daily human meals. These foods with high sugar and low water content kill bacteria. However, osmotolerant yeasts survive and multiply. The aim of this study was to examine the occurrence of intracellular Helicobacter pylori (H. pylori) and Staphylococcus spp. in yeast isolates from sugar-rich foods.

 Thirty-two yeast isolates from fresh fruits, dried fruits, commercial foods, and miscellaneous foods were identified by the sequencing of amplified products of 26S rDNA. Fluorescence microscopy and LIVE/DEAD bacterial viability kit were used to examine the occurrence of live bacteria inside the yeast’s vacuole. Immunofluorescence assay was used to confirm the identity of intracellular bacteria as H. pylori and Staphylococcus. Polymerase chain reaction (PCR) was used for the detection of 16S rDNA of H. pylori and Staphylococcus in the total DNA of yeasts.

 Yeasts were identified as members of seven genera; Candida, Saccharomyces, Zygosaccharomyces, Pichia, Meyerozyma, Metschnikowia, and Wickerhamomyces. Intravacuolar bacteria were stained green with a bacterial viability kit, revealing that they were alive. Immunofluorescence assay confirmed the identity of intracellular H. pylori and Staphylococcus spp. PCR results revealed that among the 32 isolated yeasts, 53% were H. pylori-positive, 6% were Staphylococcus-positive, 18.7% were positive for both, and 21.8% were negative for both.

 Detection of H. pylori- and Staphylococcus-16S rDNA in yeast isolates from dried fruits, and commercial foods showed the occurrence of more than one kind of endosymbiotic bacterium in yeasts’ vacuoles. While the establishment of H. pylori and Staphylococcus in yeast is a sophisticated survival strategy, yeast serves as a potent bacterial reservoir.

Organic selenium compound such as selenomethionine plays a significant function in the response to oxidative stress. Saccharomyces cerevisiae have the ability to accumulate selenium and selenium biotransformation. Selection of indigenous selenium tolerant yeast is our goals. The relationship between cell growth and selenium biotransformation was also investigated.

The screening of the yeast cell was carried out at two steps in order to select yeast with high capacity for resistance and accumulation of selenium. The isolates were selected according to produced high biomass at different concentrations of selenium. Secondly, best yeast strains from previous step were grown in presence of 25 mg/L of sodium selenite and organic selenium content was measured.

The S17 isolate showed had maximum organic selenium accumulation (2515 ppm) and biomass production (2.73 g/L) compared to the other isolates. The biomass production and organic selenium accumulation of the S17 during 120 hours was shown a direct relationship between growth and biotransformation.

This increase in organic selenium content was achieved with yeast screening. It is interesting to know that organic selenium has high bioavailability and low toxicity compared with inorganic selenium. Therefore, finding yeast strains which are resistant to selenium can be very helpful in cancer prevention.

Candiduria in hospitalized patients may represent contamination, colonization, or urinary tract in-fections. On the other hand, candidemia and upper urinary tract infection could be the complications of can-diduria. The aim of this study was to determine candiduria in hospitalized patients and identify isolated Candida species by conventional and molecular methods. This cross-sectional study was conducted on hospitalized patients in Imam Khomeini and Mostafa Khomeini hospitals in Ilam, western Iran from Jan to Dec 2016. Urine samples of hospitalized patients were col-lected during a period of 4 months for diagnosis of candiduria. Primary identification was done by conventional methods. PCR profile was carried out using phenol-chloroform method and confirmed using restriction fragment length polymorphism (PCR-RFLP) technique by MspI restriction enzyme. Candiduria was diagnosed in 18 (9.2%) cases from a total of 195 patients. Isolated yeasts were identified as C. albicans (n: 13), C. glabrata (n: 5), and C. parapsilosis (n: 1) in the one case both C. albicans and C. glabrata were isolated from a urine sample. Candida urinary tract infection is becoming increasingly common in hospitalized patients but, differentia-tion fungal colonization from infection and identification of etiologic agents for optimal treatment is necessary.

The possible use of Lactobacillus brevis IBRC-M10790 with degrading phytase activity was investigated in sourdough and Barbari bread –using 20 and 30% of sourdough in the formulation- in order to enhance the nutritional bioavailability, and the efficiency of the bacteria in decreasing phytate via using in sourdough was compared to yeast. Results showed that L. brevis IBRC-M10790 has better efficiency in phytate reduction than yeast alone or the combination of yeast and bacteria, and can be effectively used for improving the nutritional properties of Barbari bread. Use of 30% sourdough in bread formulation gave the highest percentage of phytate reduction in breads. It seems that not only the percentage of sourdough (the amount of used yeast), but also fermentation time is important in reducing the level of phytate in Barbari bread. Statistical analysis revealed that pH is not the major factor for phytate reduction in Barbari breads with different percentages of sourdough.

Selenium (Se) as a vital trace element has many biological activities such as anti-inflammation and anti-oxidation. Selenomethionine as an organic selenium plays a vital role in the response to oxidative stress. At present, Saccharomyces cerevisiae is one of the best microorganisms that has the ability to accumulate selenium. Production of Seleno-yeast was done by growing Saccharomyces cerevisiae in the presence of water soluble selenium salt (Na2SeO3) as a part of the medium. The yield of selenium biotransformation and yeast biomass can be improved by optimizing the process conditions in two steps. First, the effects of several culture parameters (culture conditions and culture media) were studied using the Plackett-Burman design. After that, determining the optimum levels of the effective parameters was performed by Box-Behnken response surface methodology. Optimization of the conditions was performed with the aim of simultaneously optimizing the biomass and selenium biotransformation. In this investigation, the effect of the eleven culture parameters was studied with Plackett-Burman design. Then, four significant culture parameters such as glucose concentration, aeration, selenium concentration, and temperature were optimized with Box-Behnken response surface methodology.

Background and Herbal toothpastes are more secure and efficacious and less poisonous due to containing natural chemicals as compared with the synthetic toothpastes. The present study aimed to formulate a polyherbal toothpaste using accessible medicinal plants in Iran and evaluate its efficiency in the protection of oral hygiene and prevention of dental caries. The developed toothpaste was made of the leaf extracts of Artemisia dracunculus, Satureja khuzestanica (Jamzad), and Myrtus communis (Linn), combined at four different dilutions, namely 1:4 (25%), 1:1 (50%), 3:4 (75%), and (100%), with sterile distilled water. The product was tested against five microorganisms, including Streptococcus mutans, Lactobaccilus caseie, S. sanguis, S. salivarius, and Candida albicans, using agar well diffusion method. After 24 h of incubation, the maximum mean diameters of inhibition zone against L. caseie and C. albicans were obtained as 17-30 and 10-25 mm, respectively. Furthermore, the minimum mean diameter of inhibition zone against S. salivarious was estimated as 15-20 mm. The formulated toothpaste showed potent inhibitory activities against Gram-positive bacteria and C. albicans. Therefore, more studies are required to accurately investigate the efficacy of the formulated toothpaste

Human immunodeficiency virus (HIV) is a debilitating challenge and concern worldwide. Accessibility to highly active antiretroviral drugs is little or none for developing countries. Production of cost-effective microbicides to prevent the infection with HIV is a requirement. Cyanovirin-N (CVN) is known as a promising cyanobacterial lectin, capable of inhibiting the HIV cell entry in a highly specific manner.
This review article presents an overview of attempts conducted on different expression systems for the recombinant production of CVN. We have also assessed the potential of the final recombinant product, as an effective anti-HIV microbicide, comparing prokaryotic and eukaryotic expression systems.
Artificial production of CVN is a challenging task because the desirable anti-HIV activity (CVN-gp120 interaction) depends on the correct formation of disulfide bonds during recombinant production. Thus, inexpensive and functional production of rCVN requires an effective expression system which must be found among the bacteria, yeast, and transgenic plants, for the subsequent satisfying medical application. Moreover, the strong anti-HIV potential of CVN in trace concentrations (micromolar to picomolar) was reported for the in vitro and in vivo tests.
To produce pharmaceutically effective CVN, we first need to identify the best expression system, with Escherichia coli, Pichia pastoris, Lactic acid bacteria and transgenic plants being possible candidates. For this reason, heterologous production of this valuable protein is a serious challenge. Since different obstacles influence clinical trials on microbicides in the field of HIV prevention, these items should be considered for evaluating the CVN activity in pre-clinical and clinical studies.