Encapsulated Yeast Cells Research Articles

Engineering Living Material for Controlled Fragrance Release Utilizing Kluyveromyces marxianus CBS6556 and Adaptive Hydrogel.

The demand for controllable fragrance materials is substantial owing to their potential to impart enduring scents in a variety of applications. However, the practical application of such materials has been limited by challenges in tunable morphogenesis, structural variability, and adaptability to diverse conditions. In our study, we introduce a hybrid living material that integrates a genetically engineered strain of Kluyveromyces marxianus CBS6556 with an adaptive hydrogel. The engineered K. marxianus achieved temperature stability in 2-phenylethanol (2-PE) and 2-phenylethyl acetate (2-PEAc) production by expressing relevant genes in the 2-PE metabolic pathway using the high-temperature preferential promoter SSE1. The enhanced water retention capacity supports the metabolic activities of the encapsulated yeast cells, ensuring their survival and functionality over an extended period. Fragrance-releasing living material (FLM) is designed to controllably emit fragrance 2-PE by adjusting the microbial concentration within the hydrogel matrix. The FLM exhibits versatile adhesion capabilities, effectively binding to a spectrum of surfaces such as wood, textiles, and glass as well as to natural substrates like leaves. This adaptability enhances the material's applicability across various settings. Furthermore, FLM can be crafted into various forms, including microbeads, fibers, and films. This research opens up new horizons for controlled fragrance release of living materials.

Recurrent Fatal Cryptococcal Meningitis in a Patient with Liver Transplant: A Case Report and Review of Literature

Introduction: Cryptococcal meningitis is a significant leading cause of death among individuals with HIV worldwide. It is caused by Cryptococcus neoformans and the C. gattii species complex. The primary predisposing factor is HIV, but it can also be observed in conditions such as immunodeficiency, sarcoidosis, liver disease, solid organ transplantation, and steroid treatment. Case Presentation: This report discusses a 61-year-old man with a medical history of liver transplantation, open-heart surgery, diabetes, hypertension, and previous cryptococcal meningitis. He had been receiving antifungals and was discharged in good condition to continue maintenance treatment at home. During his latest admission, he was hospitalized to investigate weakness and suspicious ulcerated skin lesions refractory to glucantime through biopsy. Two days after hospitalization and before receiving the biopsy result, the patient gradually developed lethargy, headache, and nausea. Laboratory examinations of cerebrospinal fluid (CSF) and skin biopsies revealed encapsulated yeast cells identified as C. neoformans using culture media and the PCR method. The patient died shortly after receiving liposomal amphotericin B and oral fluconazole. Conclusions: This case emphasizes the importance of follow-up visits for high-risk patients, early screening for fungal infections, and long-term antifungal treatment, especially in immunocompromised patients, to reduce unfavorable outcomes.

Yolk-Shell Encapsulation of Cells by Biomimetic Mineralization and Visible Light-Induced Surface Graft Polymerization.

The pursuit of low-cytotoxicity modification strategies represents a prominent avenue in cell coating research, holding immense significance for the advancement of practical living cell-related technologies. Here, we presented a novel method to fabricate encapsulated yeast cells with a yolk-shell structure by biomimetic mineralization and visible-light-induced surface graft polymerization. In this approach, an amorphous calcium carbonate (ACC) shell was first deposited on the surface of a yeast cell (cell@ACC) modified with 4 layers of self-assembled poly(diallyl dimethylammonium chloride) (PDADMAC)/poly(acrylic acid) (PAA) film using a biomimetic mineralization technique. Subsequently, polyethylenimine (PEI) was absorbed on the surface of cell@ACC by electrostatic interaction. Then, a cross-linked shell was introduced by surface-initiated graft polymerization of poly(ethylene glycol) diacrylate (PEGDA) on cell@ACC under irradiation of visible light using thioxanthone catechol-O,O'-diacetic acid as the photosensitizer. After the removal of the inner ACC shell, the yolk-shell-structured yeast cells (cell@PHS) were obtained. Due to the mild conditions of the strategy, the cell@PHS could retain 98.81% of its original viability. The introduction of the shell layer significantly prolonged the lag phase of yeast cells, which could be tuned between 5 and 25 h by regulating the thickness of the shell. Moreover, the cell@PHS showed improved resistance against lyticase due to the presence of a protective shell. After 30 days of storage, the viability of cell@PHS was 81.09%, which is significantly higher than the 19.89% viability of native yeast cells.

Increasing the Efficiency of Taxifolin Encapsulation in Saccharomyces cerevisiae Yeast Cells Based on Ultrasonic Microstructuring

The aim of the present study was to investigate the possibility of encapsulating the plant antioxidant taxifolin in the living cells of the yeast Saccharomyces cerevisiae. Taxifolin is an unstable substance prone to oxidative degradation and actively enters into chemical reactions with a decrease or loss of bioactive properties. To minimize these problems, the use of encapsulation technology has been proposed. The cells of the yeast Saccharomyces cerevisiae have been chosen as a protective material for taxifolin. The encapsulation process was carried out using simple diffusion methods in living Saccharomyces cerevisiae cells in a thermostatically controlled shaker for 24 h. The aim of the study was to evaluate the effect of preliminary microstructuring of taxifolin on the efficiency of its encapsulation in yeast cells. The microstructuring process was carried out using low-frequency ultrasonic cavitation exposure for 7 min with a frequency of 22 ± 1.6 kHz and a power of 600 W/100 mL. The studies confirmed the feasibility of the proposed approach. It was found that microstructuring changes the dispersed composition of taxifolin particles and their morphology in solution and also increases the value of the antioxidant activity. Preliminary microstructuring of taxifolin increases the efficiency of its encapsulation in Saccharomyces cerevisiae yeast cells by 1.42 times compared to the initial form. A positive dependence of the growth of the encapsulation efficiency on the duration of the process was also established. Thus, the conducted studies confirmed the advantage of encapsulation of taxifolin in living cells of the yeast Saccharomyces cerevisiae in microstructured form.

Physicochemical and Morphological Study of the Saccharomyces cerevisiae Cell-Based Microcapsules with Novel Cold-Pressed Oil Blends

Vegetable oils rich in polyunsaturated fatty acids are a valuable component of the human diet. Properly composed oil blends are characterized by a 5:1 ratio of ω6/ω3 fatty acids, which is favorable from a nutritional point of view. Unfortunately, their composition makes them difficult to use in food production, as they are susceptible to oxidation and are often characterized by a strong smell. Encapsulation in yeast cells is a possible solution to these problems. This paper is a report on the use of native and autolyzed yeast in the encapsulation of oils. The fatty acid profile, encapsulation efficiency, morphology of the capsules obtained, and thermal behavior were assessed. Fourier transform infrared analysis and low-field nuclear magnetic resonance relaxation time measurements were also performed. The process of yeast autolysis changed the structure of the yeast cell membranes and improved the loading capacity. Lower encapsulation yield was recorded for capsules made from native yeast; the autolysis process significantly increased the value of this parameter. It was observed that NY-based YBMCs are characterized by a high degree of aggregation, which may adversely affect their stability. The average size of the AY capsules for each of the three oil blends was two times smaller than the NY-based capsules. The encapsulation of oils in yeast cells, especially those subjected to the autolysis process, ensured better oxidative stability, as determined by DSC, compared to fresh blends of vegetable oils. From LF NMR analysis of the relaxation times, it was shown that the encapsulation process affects both spin-lattice T1 and spin-spin T2* relaxation times. The T1 time values of the YBMCs decreased relative to the yeast empty cells, and the T2* time was significantly extended. On the basis of the obtained results, it has been proven that highly unsaturated oils can be used as an ingredient in the preparation of functional food via protection through yeast cell encapsulation.

Digitally Programmable Manufacturing of Living Materials Grown from Biowaste.

Material manufacturing strategies that use little energy, valorize waste, and result in degradable products are urgently needed. Strategies that transform abundant biomass into functional materials form one approach to these emerging manufacturing techniques. From a biological standpoint, morphogenesis of biological tissues is a "manufacturing" mode without energy-intensive processes, large carbon footprints, and toxic wastes. Inspired by biological morphogenesis, we propose a manufacturing strategy by embedding living Saccharomyces cerevisiae (Baker's yeast) within a synthetic acrylic hydrogel matrix. By culturing the living materials in media derived from bread waste, encapsulated yeast cells can proliferate, resulting in a dramatic dry mass and volume increase of the whole living material. After growth, the final material is up to 96 wt % biomass and 590% larger in volume than the initial object. By digitally programming the cell viability through UV irradiation or photodynamic inactivation, the living materials can form complex user-defined relief surfaces or 3D objects during growth. Ultimately, the grown structures can also be designed to be degradable. The proposed living material manufacturing strategy cultured from biowaste may pave the way for future ecologically friendly manufacturing of materials.

Alginate@polydopamine@SiO2 microcapsules with controlled porosity for whole-cell based enantioselective biosynthesis of (S)−1-phenylethanol

Whole-cell biocatalysis, owing to its high enantioselectivity, environment friendly and mild reaction condition, show a great prospect in chemical, pharmaceutical and fuel industry. However, several problems still limit its wide applications, mainly concerning the low productivity and poor stability. Although the biocatalyst encapsulated in the most-commonly-used alginate hydrogels demonstrate enhanced stability, it still suffers from low biocatalytic productivity, long-term reusability and poor mass diffusion control. In this work, hybrid alginate@polydopamine@SiO2 microcapsules with controlled porosity are designed to encapsulate yeast cells for the asymmetric biosynthesis of (S)− 1-phenylethonal from acetophenone. The hybrid microcapsules are formed by the ionic cross-linking of alginate, the polymerization of dopamine monomers and the protamine-assisted colloidal packing of uniform-sized silica nanoparticles. Alginate provides the encapsulated cells with highly biocompatible environment. Polydopamine enables to stimulate the biocatalytic productivity of the encapsulated yeast cells. Silica shells can not only regulate the mass diffusion in biocatalysis but also enhance the long-term mechanical and chemical stability of the microcapsules. The morphology, structure, chemical composition, stability and molecular accessibility of the hybrid microcapsules are investigated in detail. The viability and asymmetric bioreduction performance of the cells encapsulated in microcapsules are evaluated. The 24 h product yield of the cells encapsulated in the hybrid microcapsules shows 1.75 times higher than that of the cells encapsulated in pure alginate microcapsules. After 6 batches, the 24 h product yield of the cells encapsulated in the hybrid microcapsules is well maintained and 2 times higher than that of the cells encapsulated in pure alginate microcapsules. Therefore, the hybrid microcapsules designed in this study enable to enhance the asymmetric biocatalytic activity, stability and reusability of the encapsulated cells, thus contributing to a significant progress in cell-encapsulating materials to be applied in biocatalytic asymmetric synthesis industry.

Persistence Enhancement of a Promising Tick Repellent, Benzyl Isothiocyanate, by Yeast Microcarriers.

Phenethyl isothiocyanate isolated from Armoracia rusticana root oil and its derivatives were tested at different doses in a bioassay designed to evaluate repellency against individual Haemaphysalis longicornis nymphs. Among the tested compounds, benzyl isothiocyanate exhibited repellency against H. longicornis nymphs at the lowest dose of 0.00625 mg/cm2, followed by phenethyl isothiocyanate (0.0125 mg/cm2) and phenyl isothiocyanate (0.025 mg/cm2). The behavioral responses of H. longicornis nymphs exposed to benzyl isothiocyanate and phenethyl isothiocyanate indicated that the mode of action of these compounds can be mainly attributed to the vapor phase. Encapsulated benzyl isothiocyanate showed repellency up to 120 min post-application at 0.1 mg/cm2, whereas pure benzyl isothiocyanate showed repellency up to 60 min post-application at 0.1 mg/cm2. The present study suggests that benzyl isothiocyanate is a potential repellent for protection against H. longicornis nymphs, and encapsulation in yeast cells may enhance the repellency effect.

Encapsulation of peach waste extract in Saccharomyces cerevisiae cells

As a secondary industrial product, peach waste (PW) presents an ecological problem, but is potentially a rich source of natural antioxidants. A potential and novel way to improve the phytochemical stability of waste rich in phytochemicals is encapsulation in yeast cells that possess good structural characteristics. In the present study, PW extract was encapsulated in non-plasmolyzed, plasmolyzed and living Saccharomyces cerevisiae cells using the freeze-drying method. HPLC analysis revealed that ?-carotene is the most abundant carotenoid, while epicatechin and catechin are the most abundant phenolics in PW. The highest encapsulation efficiency of carotenoids (86.59 %), as well as phenolics (66.98 %), was obtained with freeze-dried non-plasmolyzed yeast cells used as carriers. Although plasmolysis can cause some changes in the structure and properties of yeast cells, it did not enhance the encapsulation efficiency of present phytochemicals. Successful encapsulation of PW extract in yeast cells was confirmed by FTIR spectroscopy and SEM imaging. The obtained results present the encapsulation of sensitive compounds in yeast cells by freeze-drying as an excellent method for preserving valuable compounds and their potential use in the food and pharmaceutical industries.

Encapsulation of Antarctic krill oil in yeast cell microcarriers: Evaluation of oxidative stability and in vitro release

Antarctic krill oil (KO) was encapsulated into yeast cells (YCs), and the physicochemical, morphological, and conformational characterizations of KO-loaded YCs (KYCs) were investigated. Moreover, the oxidation stability and in vitro release behavior of KYCs were evaluated. Results showed that KYCs provided significantly higher oxidative stability than native KO. The fatty acid profile remained obviously unchanged after encapsulation. Most interestingly, the phospholipid proportion increased from 49.76% ± 1.42% to 59.92% ± 1.39% after encapsulation. Furthermore, there was a slow and prolonged release of KYCs, along with higher bioaccessibility of docosahexaenoic acid and eicosapentaenoic acid than the KO-in-water emulsion (69.62% ± 7.67% and 66.67% ± 4.55% vs 47.44% ± 4.4% and 39.74% ± 3.89%). KO encapsulation in YCs can be considered as an efficient approach for extending the oxidative and in vitro stability of this nutritious oil and facilitating its application in food products.

Nanoencapsulation of Saccharomycopsis fibuligera VIT-MN04 using electrospinning technique for easy gastrointestinal transit.

In this study, probiotic yeast Saccharomycopsis fibuligera (S. fibuligera) VIT-MN04 was encapsulated with wheat bran fibre (WBF) and exopolysaccharide (EPS) along with 5% polyvinylpyrrolidone (PVP) using electrospinning technique for easy gastrointestinal transit (GIT). The electrospinning materials viz. WBF (10%), EPS (15%), PVP (5%) and electrospinning parameters viz. applied voltage (10 kV) and tip to collector distance (15 cm) were optimised using response surface methodology to produce fine nanofibres to achieve maximum encapsulation efficiency (100%) and GIT tolerance (97%). The probiotic yeast was successfully encapsulated in nanofibre and investigated for potential properties. The survival of encapsulated S. fibuligera VIT-MN04 was increased compared to the free cells during in vitro digestion. In addition, encapsulated yeast cells retained their viability during storage at 4°C for 56 days. The nanofibres were characterised using scanning electron microscopy, atomic force microscopy, X-ray diffraction, thermogravimetric analysis, zeta potential analysis and Fourier transform infrared spectroscopy followed by gas chromatography-mass spectrometry and nuclear magnetic resonance analysis. This work provides an efficient approach for encapsulation of probiotic yeast with the nanofibres which can also broaden the application of the prebiotic like WBF providing an idea for the efficient preparation of functional synbiotic supplements in the food industry.

Highlighting Protective Effect of Encapsulation on Yeast Cell Response to Dehydration Using Synchrotron Infrared Microspectroscopy at the Single-Cell Level.

In the present paper, the Layer by Layer (LbL) method using β-lactoglobulin and sodium alginate was performed to individually encapsulate Saccharomyces cerevisiae cells in microorganized shells in order to protect them against stresses during dehydration. Higher survival (∼1 log) for encapsulated yeast cells was effectively observed after air dehydration at 45°C. For the first time, the potentiality of Synchrotron-Fourier Transform InfraRed microspectroscopy (S-FTIR) was used at the single-cell level in order to analyze the contribution of the biochemical composition of non-encapsulated vs. encapsulated cells in response to dehydration. The microspectroscopy measurements clearly differentiated between non-encapsulated and encapsulated yeast cells in the amide band region. In the spectral region specific to lipids, the S-FTIR results indicated probably the decrease in membrane fluidity of yeast after dehydration without significant distinction between the two samples. These data suggested minor apparent chemical changes in cell attributable to the LbL system upon dehydration. More insights are expected regarding the lower mortality among encapsulated cells. Indeed the hypothesis that the biopolymeric layers could induce less damage in cell by affecting the transfer kinetics during dehydration-rehydration cycle, should be verified in further work.

Encapsulation of Zataria multiflora Essential Oil in Saccharomyces cerevisiae: Sensory Evaluation and Antibacterial Activity in Commercial Soup

Nowadays rising consumer concern on the safety of synthetic chemical food preservatives is a reason for finding natural new antimicrobial agents, especially among the components of medicinal plants such as Essential Oils (EOs). However, most EOs are sensitive to oxygen, light, and temperature and can be easily degraded. Some EOs have strong taste, flavor, and affect the organoleptic characteristics of foods. Encapsulation can control these unpleasant characteristics. Using yeast cells as encapsulating agents and delivery systems for active ingredients has been widely investigated. Encapsulation in yeast cells has a wide range of advantages such as processes simplicity, commercial availability, low cost-high volume process, and needless of toxic solvents. In this study, the antibacterial activity of free and encapsulated Zataria multiflora Bioss. Essential Oil (ZEO) in Saccharomyces cerevisiae against Escherichia coli O157:H7 and Listeria monocytogenes as important foodborne pathogens were evaluated. The sensory evaluation of both forms of ZEO in a food model was also done. ZEO was successfully encapsulated into S. cerevisiae cells. Carvacrol and thymol contents in loaded yeasts were determined. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of free and loaded ZEO were studied against Escherichia coli O157:H7 and Listeria monocytogenes; their antibacterial effects in the commercial chicken soup was investigated, and their sensory attributes in the commercial soup were evaluated as well. Our results showed significant decreases in the MIC and MBC values of ZEO in culture media after encapsulation; however, the antibacterial activity of ZEO in commercial chicken soup showed no significant differences after encapsulation (P>0.05). ZEO encapsulation improves its sensory score and hence, decreases its organoleptic effects in food (P<0.01). Considering acceptable sensorial scores of loaded ZEO in yeast cells, this method can practically be applied in food systems as natural biopreservation.

Encapsulation of live cells by metal-organic frameworks for viability protection

In this study, a yeast@ZIF-8 core–shell composite material was successfully synthesized under room temperature in aqueous solution. The ZIF-8 shell endowed the inner yeast cells with a considerably extended lifetime without any nutrients at 4°C. Compared with the bare yeast cells, most coated yeast cells were kept alive even when cultured in zymolyase solution for 3 h. Furthermore, the encapsulated yeast cells could be reactivated and regrown by dissolving the ZIF-8 shell with competitive coordination interactions.

FERMENTATION CHARACTERISTICS OF CAMPBELL EARLY GRAPE WINE INOCULATED WITH INDIGENOUS KOREAN WINE YEASTS ENCAPSULATED IN CA-ALGINATE BEADS AFTER AIR-BLAST DRYING

The aim of this study was to test the possibility of using yeast cells encapsulated in calcium alginate (Ca-alginate) beads as a starter for wine fermentation. Characteristics of Korean Campbell Early wines fermented by five free yeast cell types and those encapsulated in 2% Ca-alginate beads were compared using physicochemical analyses and sensory evaluation tests. The encapsulated yeast cells were shown to ferment Korean Campbell Early grapes with a similar efficiency as that exhibited by the five free yeast cell-types. After fermentation, the characteristics of free cells and encapsulated cells did not show significant differences in terms of content of reducing sugars, soluble solids, total acids, organic acids, and free sugars, as well as in terms of viable cell numbers and other physicochemical properties. The encapsulated cells did, however, produce more alcohol than the free cells. Encapsulation in 2% Ca-alginate beads was furthermore found to decrease the production of negative volatile compounds. The sensory evaluation of wines fermented by free cells compared with those fermented by Ca-alginate bead-encapsulated cells yielded similar scores for the following properties: color, taste, flavor, and overall preference. Overall, no significant differences were observed between the two grape wines, and yeast cells encapsulated in 2% Ca-alginate beads therefore showed high stability and served as an effective yeast starter for wine fermentation.

Encapsulation of Hibiscus sabdariffa L. anthocyanins as natural colours in yeast

Hibiscus sabdariffa extracts, a rich source of anthocyanin, were subjected to encapsulation in yeast cells. An encapsulation yield (EY) of 208 μg/100 mg of cells and an encapsulation efficiency (EE) of 27%, were reached after optimisation of the ratios (0.5 g wet yeast cells for 5 ml of anthocyanin extracts at 1 g·L−1) and with 10% of ethanol. The storage stability of encapsulated pigments was investigated in water and buffer pH 1.5 at 5 & 37 °C for 10 days and 90 °C for 30 min. The percentage of loss of colour was determined by colourimetry assays. The microparticles made of yeast with or without heat treatment exhibited different protecting effects (P < 0.01). At 37 °C, the percentage of loss of colour in water was of 2.5% for heat-treated and 36.5% for non-treated yeast microparticles, suggesting that yeast enzymes would be responsible for the loss of anthocyanin during storage. These results are confirmed by the percentage of loss of colour which was far lower in conditions of low enzymatic activity: 3.1% at 5 °C for non-heat-treated cells in water. The pH of solvent had also an important effect on the degradation of encapsulated anthocyanin; in buffer at pH 1.5 and 37 °C with the non-heat-treated cells, the degradation decreased strongly to 9.4% compared with 36.5% in water. These results show that yeast cells are a good mean of encapsulation of pigments for a colouring purpose and that they provide anthocyanins a good protection as long as their enzymes are inactivated.

Integrated system of multiple batches to evaluate the continuous performance of microbial cells in decolourization processes

Azo dye degradation in wastewater treatment is a subject which has garnered the attention of many research studies. In this study, an innovative approach, namely, an integrated system of five batches (ISFB), was developed to investigate the capability of Saccharomyces cerevisiae ATCC 9763 for continuous degradation of methyl red as a representative azo dye. Toward this end, an expanded immobilized microbial bed (EIMB) reactor was established with a bed of encapsulated yeast cells in sodium alginate. EIMB reactor was run in two modes, single batch and ISFB. Moreover, durability of the microbial cells was evaluated by repeating the continuous decolourization eight sequential times in EIMB at ISFB mode with the same cells. ISFB set-up can simulate a continuous process while avoiding the complexity of utilizing continuous reactors. Spectrophotometry results show that 6 ± 0.17 h was required for complete decolourization in EIMB reactor at single batch mode which estimates a decolourization rate (RDec) of 8.9 ± 0.3 g h−1in this set-up. Subsequently, decolourization rate incrementally increased ≃2.8 times while ISFB mode was applied to the EIMB system and this rate was approximately maintained during eight consecutive runs. The changes in morphology and bioavailability of the immobilized S. cerevisiae were monitored through scanning electron microscopy.

Effect of polyethylene glycol additives on structure, stability, and biocatalytic activity of ormosil sol–gel encapsulated yeast cells

Biohybrid materials based on ormosil encapsulated yeast cells were synthesized through a one-step sol–gel route with base-catalyst (NaF) using tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and polyethylene glycol (PEG) with different molar weights as a structure-controlling agent. Phase contrast microscopy and scanning electron microscopy were employed to evidence possible structures of the materials. The addition of PEG during cell encapsulation has induced structural changes within the biohybrids, which depend on PEG molecular weights. The biocatalytic activity of the living hybrids has been investigated by a biosensor which was based on the Clark-type oxygen electrode.

Improvement of oxidative stability of menhaden fish oil by microencapsulation within biocapsules formed of yeast cells

Fish oil, rich in polyunsaturated fatty acids, is a valuable addition to human diet. Its composition makes it difficult to handle as it is prone to oxidation and its strong smell is repelling to many. Encapsulation in yeast cells is a possible solution to these issues. The aim of this study was to determine the best pretreatment approach, optimize the process of microencapsulation and verify the stability of the oil encapsulated in Saccharomyces cerevisiae. Pretreatment by autolysis, chemically facilitated autolysis and enzymatic cell wall digestion was tested. Autolysis at 55°C supported by addition of 1.5% ethyl acetate was an effective pretreatment method. Process parameter values (temperature, stirring rate and emulsifier addition) were optimized, improving efficiency to ca. 90%. The encapsulated oil was shown to be stable when stored for 30days at relative humidity below 70%. Additional coating with hydroxypropyl methyl cellulose allowed to improve storage stability.

Primary Cutaneous mycosis in an Immunocompetent Parrot Keeper Due to Cryptococcus neoformans

The prime objective of this paper is to delineate the etiologic significance of Cryptococcus neoformans in primary cutaneous mycosis of a 34- year- old male immunocompetent person, who was occupationally exposed to the excreta of a caged parrot. The biopsy obtained from the cutaneous lesion of a parrot keeper was examined in Indian ink mount, and was cultured onto the plates of Pal’s sunflower seed medium. In addition, the urine and blood of patient was also inoculated on Pal’s sunflower seed medium to rule out the systemic infection. In order to establish the source of infection, samples of parrot droppings, and wooden box were examined on Pal’s sunflower seed medium. Microscopic examination of clinical specimen in India ink preparation revealed circular, wide, thickly encapsulated yeast cells of Cryptococcus neoformans . Numerous dark brown colored colonies of C. neoformans grew from biopsied tissue on Pal’s sunflower seed medium. The microscopic morphology of the fungal isolates was done in Narayan stain. There was no growth of C. neoformans from blood, and urine of the patient on Pal’s sunflower seed medium. The pathogen was easily recovered from the parrot droppings, and wooden box on Pal’s sunflower medium. These findings conclusively established that the patient acquired primary cutaneous cryptococcosis from his immediate environment as revealed by the presence of C. neoformans in the excreta, and wooden cage of the caged parrot.