Search

Limited knowledge exists on the virulence factors of Candida tropicalis and the mechanisms of azole resistance that lead to an intensified pathogenicity and treatment failure. We aimed to evaluate the virulence factors and molecular mechanisms of azole resistance among C. tropicalis isolated from patients with candidemia. Several virulence factors, including extracellular enzymatic activities, cell surface hydrophobicity (CSH), and biofilm formation, were evaluated. Antifungal susceptibility pattern and expression level of ERG11, UPC2, MDR1, and CDR1 genes of eight (4 fluconazole resistance and 4 fluconazole susceptible) clinical C. tropicalis isolates were assessed. The correlation between the virulence factors and antifungal susceptibility patterns was analyzed. During a 4 year study, forty-five C. tropicalis isolates were recovered from candidemia patients. The isolates expressed different frequencies of virulence determinants as follows: coagulase 4 (8.9%), phospholipase 5 (11.1%), proteinase 31 (68.9%), esterase 43 (95.6%), hemolysin 44 (97.8%), biofilm formation 45 (100%) and CSH 45(100%). All the isolates were susceptible to amphotericin B and showed the highest resistance to voriconazole. There was a significant positive correlation between micafungin minimum inhibitory concentrations (MICs) and hemolysin production (rs = 0.316). However, we found a negative correlation between fluconazole MICs and esterase production (rs = −0.383). We observed the high expression of ERG11 and UPC2 genes in fluconazole-resistant C. tropicalis isolates. C. tropicalis isolated from candidemia patients extensively displayed capacities for biofilm formation, hemolysis, esterase activity, and hydrophobicity. In addition, the overexpression of ERG11 and UPC2 genes was considered one of the possible mechanisms of azole resistance.

Background Virulence factors intensify the pathogenicity of Candida species in candidemia. Limited knowledge exists regarding the azole-resistant mechanism and virulence factors of Candida tropicalis. Consequently, we aimed to evaluate the virulence factors and the molecular mechanisms of azole resistance among C. tropicalis isolated from bloodstream infection. Materials and methods Forty-five C. tropicalis isolates recovered from candidemia patients were evaluated for virulence factors, including extracellular enzymatic activities, cell surface hydrophobicity (CHS), and biofilm formation. Antifungal susceptibility pattern and expression level of ERG11, UPC2, MDR1, and CDR1 genes of eight azole resistance C. tropicalis isolates were assessed. Results The isolates expressed different frequencies of virulence determinants as follows: coagulase 4 (8.9%), phospholipase 4 (8.9 %), proteinase 31 (68.9 %), CSH 43 (95.6 %), esterase 43 (95.6 %), hemolysin 44 (97.8%), and biofilm formation 45 (100%). All the isolates were susceptible to amphotericin B and showed the highest resistance to voriconazole. The high expression of ERG11 and UPC2 genes in fluconazole-resistant C. tropicalis isolates were observed. Conclusion C. tropicalis isolated from candidemia patients extensively displayed capacities for biofilm formation, hemolysis, esterase activity, and hydrophobicity. In addition, the overexpression of ERG11 and UPC2 genes can be considered as one of the possible mechanisms of azole resistance.

Biofilm formation by Candida species is an influential virulence factor in candidemia pathogenesis. We investigated the relationship between biofilm formation of Candida tropicalis isolates with the clinical characteristics and mortality outcomes in patients with candidemia.Thirty-nine C. tropicalis isolates were recovered from patients with candidemia admitted to two university hospitals in Tehran, Iran. Biofilm mass and metabolic activity of C. tropicalis biofilms were assessed in vitro with two colorimetric methods. The sessile minimum inhibitory concentrations (SMICs) were evaluated in vitro by treating preformed biofilms with diluted concentrations of azoles according to CLSI-M27 A3/S4 protocol, followed by metabolic activity quantification. The expressions of ERG11, UPC2, MDR1, and CDR1 genes were also evaluated.All C. tropicalis isolates produced biofilm. Respectively, higher7-day and ≥7-day mortality rates were found among cases with high metabolic activity (46.7% vs. 13%, P = 0.03) and high biofilm mass (31.8% vs. 0, P = 0.029). Sessile cells had high resistance to fluconazole, voriconazole, and itraconazole. The azole minimum inhibitory concentrations (MICs) of C. tropicalis sessile were significantly greater than the planktonic minimum inhibitory concentrations (PMICs). In fluconazole-treated biofilms, the expression of ERG11 and UPC2 genes was increased.Our findings highlight the importance of C. tropicalis biofilm formation as an important factor in candidemia pathogenesis and the clinical outcome of patients with candidemia.

1 , respectively. The combination of caffeine with FLU showed stronger antifungal activity against C. albicans PTCC5027. The addition of 12.5mgL -1 caffeine to FLU 10-50 mgL -1 (below MIC90) inhibited the growth of C. albicans PTCC5027 by 99.3%-99.7%, the concentrations at which neither caffeine nor FLU alone affected the growth. Conclusion: It can be concluded that caffeine has antifungal effect on C. albicans and in combination with FLU can enhance the antifungal activity of FLU against C. albicans . The synergism of the combination of caffeine and FLU induces multiple antifungal effects, resulting in the use of lower doses of the FLU. It suggests that this can decrease the side effects of antifungal drugs.

Background: The importance of Candida albicans as the most common cause of fungal infections in humans is undeniable. Genotyping methods have been developed as useful tools to differentiate between fungal strains isolated from various infections. Several molecular typing methods have been described for C. albicans, and fragment length analysis of microsatellites called microsatellite fragment length polymorphism (MLP) is one of the most accurate genotyping methods. Objectives: The present study aimed at evaluating the genetic diversity and genetic relationships among C. albicans isolates recovered from HIV-positive patients with oral candidiasis in Iran using MLP. Methods: We analyzed 30 isolates of C. albicans obtained from HIV-positive patients in Tehran. Genotypes of C. albicans isolates associated with oropharyngeal candidiasis were determined using microsatellite length polymorphism analysis. Three loci including EF3, CDC3, and HIS3 were amplified using multiplex PCR. After amplification, the product was run on an automated single-capillary genetic analyzer, and band sizes (known as alleles) were calculated with gene scan mapper. Results: PCR MLP typing of the 30 isolates under study yielded 27 different profiles, and the discriminatory power index was obtained as 0.993. Ten alleles and 18 different combinations were detected for the EF3 gene, 7 alleles and 18 combinations for the EF3 gene, and 10 alleles and 14 combinations for the HIS3 gene. Only 2 isolates were homozygous in all the 3 loci. To identify the origin of superficial infections in 6 patients, C. albicans isolates from the superficial as well as oral samples were simultaneously genotyped. Results showed the identity of genotypes in 4 of these patients. For 1 patient, the C. albicans genotype of the nails was different from the genotype observed in the oral cavity, which raised the possibility of an exogenous source for the superficial infection. Also, there were changes at only 1 or 2 alleles, which represented microevolution in some isolates. Conclusions: The high variation of genotypes throughout the population of C. albicans suggested that the microsatellite fragment length polymorphism using multiplex PCR-based system provided high-speed genotyping, indicating its usefulness in molecular epidemiological evaluation.

Secreted aspartyl proteinases (Saps), are gene products that have been shown to directly contribute to Candida albicans pathogenicity. Despite the clear difficulties of systemic C. albicans infections control, Antimicrobial peptides (AMPs) are regarded as one of the most promising alternatives in this regard. Recently, drug-loaded electrospun nanofibers have attracted a great deal of attention. In this study we have established the nanofibrous scaffold of new synthetic peptide/Poly (Vinyl Alcohol)/Poly l-Lactic Acid on expression of Secretory aspartyl proteinases 4 to 6 genes of C. albicans in comparison with free peptide. We designed new synthetic Antimicrobial peptide (AMPs) used bioinformatics tools to predict structure and stabilities. The electrospinning method was used to produce the polymeric nanofibers. Scanning Electron Microscopy (SEM) was used to measure the nanofibers diameters and morphology. To analyze the expression of SAP4, SAP5 and SAP6 genes, RNA was extracted from clinical isolates of C. albicans before and after treatment with subinhibitory concentrations of new synthetic peptide on nanofibrous scaffold of new synthetic peptide/PVA/PLLA and then the cDNA was synthesized and used for Real-time PCR assay. Scanning electron microscopy (SEM) images showed that the morphology, the diameter, are affected from peptide. Reletive quantitative Real-time PCR results revealed that the mRNA levels of SAP4, SAP5 and SAP6 genes significantly decreased after treatment with nanofibrous scaffold of new synthetic peptide/PVA/PLLA (P .05). Electrospun nanofibrous of new Synthetic Peptide/PVA/PLLA is effective in downregulating of expression SAP4, SAP5 and SAP6 genes of C. albicans strains.

Background: Candida albicans is the most common pathogen in patients with vulvovaginitis. Secretory aspartyl proteinases (SAPs) are potential factors in the virulence of C. albicans. Antimicrobial peptides (AMPs) are recognized as a promising antimicrobial group of drugs with a membrane degradation mechanism. Occurrence of resistance to these drugs is quite rare. The impact of rapid membrane degradation on AMPs is relative to the prevention or delay in drug resistance mechanisms in different microbes. Objectives: The purpose of this study was to compare the inhibitory effects of the designed NK95 peptide and caspofungin on expression of SAP4-SAP6 genes from clinical vaginal isolates of C. albicans . Methods: In this experimental study, samples were collected from 350 women, who were suspected of vulvovaginal candidiasis and were referred to Zahedan gynecology clinics during 6 months. The clinical specimens were cultured in Sabouraud glucose agar (SGA). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to identify the vaginal isolates of C. albicans. Afterwards, the NK95 peptide was designed and synthesized. Drug susceptibility test was carried out at different concentrations of NK95 peptide and caspofungin. RNA extraction, cDNA synthesis, and quantitative Real-time PCR were performed on the clinical isolates before and after treatment with the designed peptide and caspofungin. Results: Based on the findings of this study, the minimum inhibitory concentration (MIC90), MIC50, and minimum fungicidal concentration (MFC) of C. albicans isolates were 62.5, 31.25, and 125 μg/mL for the designed peptide, respectively. The SAP4 (45%), SAP5 (85%), and SAP6 (73%) genes expressions significantly reduced at 48 hours after treatment with the designed peptide (P < 0.05). Conclusions: Our findings showed that the designed NK95 peptide has antifungal effects on the clinical vaginal isolates of C. albicans. Moreover, it has potential down-regulating on expression of SAP4, SAP5 and SAP6 genes.

In this paper, a new mathematical model has been presented to determine the equilibrium segregation ( k 0 ) and effective segregation ( k eff ) coefficients for neodymium (Nd) in YAG crystal grown by Czochralski (CZ) method. Determination of diffusion coefficient ( D L ) of Nd impurity in molten YAG is also investigated. In this model, utilizing Lambert W-function is a new idea to solve the Scheil equation for calculation of effective segregation coefficient. The Nd concentration in the crystal has been measured by optical absorption method to calculate k eff . The analyses show that the k eff is related to the growth parameters such as crystal growth rate ( u g ) and crystal rotation rate ( ω ), ( k eff ~ u g / ω ) but it is independent of the Nd concentration in the initial melt ( C 0 ). Based on obtained k eff and experimental growth data, k 0 and D L of Nd in molten YAG have been calculated. For all experiments, the average value of k 0 =0.216 and D L =1.4×10 −6 (cm 2 /s) are obtained. Our results are corroborated by the theoretical and experimental data from the literature.

A non-contact strain measurement technique, based on an in-situ digital image correlation (DIC) method in association with magnetic martensite point measurement (Feritoscopy testing) was applied to study inhomogeneous deformation corresponding to martensitic transformation of a microalloyed low carbon transformation induced plasticity steel during tensile straining. The progress of inhomogeneous deformation is traced by the strain maps. The microstructural observation is used to validate the DIC results. The experimental steel shows continuous yielding with a high true fracture strength of 1410±10 MPa at 25 °C along with the lack of tensile necking. The DIC results show that the yield point is controlled by stress-assisted martensite transformation, which in turn induces the strain inhomogeneity. The latter starts prior to the yield point after straining to 0.016. The microstructural evolution reveals the e-martensite is obtained through stress-assisted martensite formation. After yielding, thanks to the strain-induced martensite transformation, the deformation inhomogeneity in strain maps is increased with strain, corresponding to increasing the volume fraction of martensite. The results suggest that the continuous yielding and initial strain hardening is controlled by stress-assisted martensite formation while the higher total elongation to fracture (80%) and the tensile necking behavior is mainly influenced by the strain-induced martensite transformation.

In this research, formation of gaseous cavity defect in 1 at%Nd:YAG single crystal grown by the Czochralski technique has been studied. Growth atmosphere pressure and crystal rotation rate were optimized in order to prevent the defect formation. The microstructure of the defect was characterized using scanning electron microscopy (SEM) and wavelength dispersive spectroscopy (WDS) analyses. The stresses induced by the gaseous cavity were also investigated by parallel plane polariscope. The results show that the growth atmosphere pressure has a more significant influence on defect formation compared to the crystal rotation rate. In addition, decreasing the growth atmosphere pressure leads to growth of the crystals with no gaseous cavity defect. The results also show that Nd concentration varies around the defect making these areas useless for solid-state lasers application.

In this paper, the effect of two kinds of thermal shocks on the quality of Nd:YAG single crystal grown by Czochralski method have been investigated. The shocks induced by unexpected change in water flow of cooling system, have a drastic influence on the stability of growth process. This is the intensity and duration of the shocks that affect on the crystal quality as it is evaluated by parallel plane polariscope and Fizeau interferometer. The experimental findings indicate that the time duration of the shocks has more undesirable influence on the crystal quality than the intensity of shocks. Duration of the shocks could make the crystal not suited for laser applications.

Introduction: Pseudomonas aeruginosa is a key opportunistic pathogen causing severe acute and chronic nosocomial infections in immunocompromised or catheterized patients. It is prevalent in burn wound infections and is generally multi-drug resistant.This study evaluated antimicrobial activity of ZnO nanoparticles, catechin and EDTA on the most common pathogen bacteria, Pseudomonas aeroginusa, by standard microdilution test depending on NCCLS. Material and Methods: Zinc acetate dehydrate and ethilen glycol (EG) were dissolved in 50 ml distilled water with a ratio of 10/1 (Zn/EG). The solution was heated at 80 0 C until a little gel of zinc acetate was obtained. Then, the gel was dried in the oven for 12h. The dried gel was calcinated at 300 0 C for 24h. The size and type of these nanoparticles were characterized by scanning electron microscopy (SEM) and X-Ray-: Diffraction (XRD). Pseudomonas aeroginusa strain (ATCC 27853) were cultured on nutrient agar medium (NA) for 24h at 37 0 C. The microbial suspension (1×10 6 cells/ml) was prepared. Minimum Inhibitory Concentration (MIC) test for ZnO, EDTA and Catechin were evaluated by microdilution test. Results: Evaluation of morphology and measurement of the size of the ZnO showed that nanoparticles were spherical with a diameter of 30-90 nm. MIC of ZnO, EDTA and Catechin on pseudomonas aeroginusa was 0.0003, 24.92 and 7.24 μg/ml, respectively. Conclusion: In this study, ZnO nanoparticles were synthesized using the chemical method. It was revealed that it has an optimal antimicrobial activity in low concentration as compared with Catechin and EDTA. It is recommended that catechin and ZnO nanoparticles are good candidates for eliminating some contaminations including Pseudomonas aeroginusa in medical industrial.

In this study, anti proliferative activity of structural proteins and fraction of supernatant from culture of Candida albicans on proliferation responses of lymph node cells in Balb/c mice have been evaluated. For this reason Candida albicans was cultured in RPMI medium supplemented with 10% FBS at 37 in 5% CO2 until reaching a confluent state for 2 weeks. The culture supernatant was obtained by centrifugation and purified by gel filtration chromatography and structural proteins of C. albicans were obtained from breakage of cell wall by vortexing with glass beads in suspension of PBS and 1 mM PMSF and then cultured with lymph node cells and evaluated by MTT assay. The results in this study demonstrated that both of structural proteins and fraction of supernatant from culture of Candida albicans suppress immune responses compared with Control group. Our study provides evidence that proteins of C. albicans have anti proliferative activity.

Background: Some genes may be associated with Candida albicans resistance to azoles. Pir1 gene is described as responsible to induce resistance in C. albicans. Objectives: The current study aimed to find the relationship between fluconazole resistance and Pir1 protein (Pir1p) overexpression in the females with recurrent C. albicans vaginitis requiring longer fluconazole therapy. Patients and Methods: A total of 52l vaginal samples were obtained from the females with C. albicans vaginitis. The azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute (CLSI) protocol for disk diffusion method and inhibition zone for fluconazole. Expression of pir1 gene and fluconazole -resistance were evaluated using polymerase chain reaction (PCR) in C. albicans. Results: In the 52 isolates, 49 (94%) were resistant to fluconazole. Overexpression of Pir1 gene was detected in 47 (96%) fluconazole-resistant C. albicans isolates. Conclusions: The findings show fluconazole -resistance in C. albicans isolates with overexpression of Pir1p.

We fabricated a targeted delivery system for doxorubicin (Dox) using β-1,3-glucan (Glu) as a carrier and decorated by trastuzumab antibody having the status of targeting agent against Her2+ breast tumors. Glu-Dox conjugates were also functionalized with polyethylenimine (PEI) intended for increasing specific cellular uptake of prepared nanoparticles. The self-assembled nanoparticles were prepared through conjugation of Dox- [Glu-Dox-] using succinic anhydride (Sa) in place of a linker. Nanoparticles had spherical morphology with positive zeta potential. In-vitro cell viability assay on two breast cancer cell lines demonstrated acceptable toxicity against tested cell lines. Confocal microscopic images demonstrated the remarkable cytoplasmic uptake of the nanoparticles in Her2-overexpressing 4T1 cells. A controlled release of Dox from Glu-Dox nanoparticles was investigated. In-vivo studies were performed on female Balb/C mice. The volume of the induced tumors was calculated following intravenous administration of nanoparticles. The tumor volume diminished efficiently and more rapidly after administration of nanoparticles containing Dox. Based on survival results, the formulation of Dox targeted nanoparticles appeared very promising for the treatment of tumors. It could be concluded that Glu-Dox targeted nanoparticles have potential advantages for delivering anticancer drugs to the target tissue.

Allergens from Fusarium solani Identified by Immunoblotting in Asthma Patients In IranWe extracted Fusarium solani antigens to evaluate specific anti-F. solani IgE in fifty-one patients with asthma (33 men and 18 women) and in 22 non-atopic healthy subjects (15 men and 7 women). F. solani strains were cultured in Sabouraud glucose agar and subjected to cell disruption using the freeze-and-thaw method. The obtained cytoplasmic extracts were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Sensitisation to F. solani antigens has been evaluated in asthmatic patients using the immunoblotting assay. The SDS-PAGE identified 29 protein bands in the cytoplasmic extracts of F. solani isolates, with molecular weights ranging from 24 kDa to 112 kDa. Immunoblotting detected specific anti-F. solani IgE antibody in all asthma patients, but not in the control group. The predominant reactive allergens in patients corresponded to the bands with molecular weights of 24 kDa, 58.5 kDa, 64.5 kDa, 69 kDa, 72 kDa, and 97 kDa. Our results suggest that various allergenic components of F. solani may produce symptoms of asthma in susceptible individuals and they call for further research.

We extracted Fusarium solani antigens to evaluate specifi c anti-F. solani IgE in fifty-one patients with asthma (33 men and 18 women) and in 22 non-atopic healthy subjects (15 men and 7 women). F. solani strains were cultured in Sabouraud glucose agar and subjected to cell disruption using the freeze-and-thaw method. The obtained cytoplasmic extracts were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Sensitisation to F. solani antigens has been evaluated in asthmatic patients using the immunoblotting assay. The SDS-PAGE identifi ed 29 protein bands in the cytoplasmic extracts of F. solani isolates, with molecular weights ranging from 24 kDa to 112 kDa. Immunoblotting detected specific anti-F. solani IgE antibody in all asthma patients, but not in the control group. The predominant reactive allergens in patients corresponded to the bands with molecular weights of 24 kDa, 58.5 kDa, 64.5 kDa, 69 kDa, 72 kDa, and 97 kDa. Our results suggest that various allergenic components of F. solani may produce symptoms of asthma in susceptible individuals and they call for further research., Ekstrahirali smo antigene plijesni Fusarium solani kako bismo izmjerili imunosni odgovor, tj. razine anti-F. solani IgE u 52 bolesnika s astmom (33 muškarca i 18 žena) te u 22 zdrava ispitanika bez atopija (15 muškaraca i sedam žena). Sojevi F. solani uzgojeni su na podlozi glukoznoga Sabouraudova agara i podvrgnuti razbijanju stanica s pomoću metode smrzavanja i odmrzavanja. Dobiveni citoplazmatski ekstrakti analizirani su s pomoću elektroforeze u poliakrilamidnom gelu u prisutnosti natrijeva dodecilsulfata (engl. sodium dodecyl sulphate-polyacrylamide gel electrophoresis, krat. SDS-PAGE). Senzibilizacija na antigene F. solani u bolesnika s astmom utvrđena je s pomoću imunoblot-testa. S pomoću SDS-PAGE-a u citoplazmatskim ekstraktima izolata F. solani dokazano je 29 proteinskih vrpca. Molekulske mase razdvojenih proteina kretale su se u rasponu od 24 kDa do 112 kDa. Imunoblot-test otkrio je specifi čno anti-F. solani IgE- protutijelo u svih bolesnika s astmom, ali niti u jednog ispitanika iz kontrolne skupine. Najčešći su alergeni u bolesnika s astmom odgovarali proteinima ovih molekulskih masa: 24 kDa, 58,5 kDa, 64,5 kDa, 69 kDa, 72 kDa i 97 kDa. Naši nalazi upućuju na to da simptome astme u osjetljivih pojedinaca može izazvati više alergena soja F. solani te da ih treba podrobnije istražiti.

Candida albicans is one of the most important opportunistic pathogens that suppress immunologic mechanisms of the host. It is speculated that structural and secretory proteins of C. albicans have immunomodulatory effects in cancer.To evaluate the effects of C. albicans structural and secreted proteins on intratumoral CD4/CD8 ratio as well as the survival rate in BALB/c tumor model.Structural and secretory proteins from C. albicans were isolated and examined for their effects on tumor growth and survival of adenocarcinoma bearing mice.The results indicated that in mice treated with C. albicans structural protein, the survival rate significantly decreased compared with the control groups. Also, mice treated with secretory proteins showed a decrease in survival rate but it was not statistically significant (p0.05). Investigating the frequency of tumor infiltrated CD4+ and CD8+ T lymphocytes indicated that the percentages of tumor infiltrated CD4+ T lymphocytes in response to structural and secreted proteins were higher compared to the control groups.Our study suggests that C. albicans structural and secreted proteins modulate intratumor T lymphocyte infiltration.

Background: The incidence of mortality due to mycoses, particularly those caused by opportunistic fungi, has shown a marked increase in recent years. This happens especially in patients whose immune defense mechan-isms is compromised by antibiotics, immunosuppressive, therapy, or severe underlying disease. In this study‚ the effects of cytoplasmic proteins of candida albicans on lymphocytes were examined. Methods: Candida Albicans (Atcc 1023) was cultured in GYEP medium. Cells harvested by centerifugations were disrupted with glass beads. Disrupted yeast cells were centrifuged at 100’000 × g for 1 hour and superna-tant was taken as cytoplasmic extract. SDS –PAGE ٍwas done to determine molecular weight. In order to further purify the cytoplasmic extract‚ gel filtration (G200) was used. Mice were divided in five groups: two groups were sensitized with active and inactive cells (both groups with adjuvant) and the other three groups were sensitized with complete adjuvant, incomplete adjuvant and physiologic serum. After seven days of the last injection‚ spleens were removed and lymphocytes were isolated. MTT assay was used in order to measure lymphocytes proliferation. IL4 and IFN-γ cytokines were thereafter measured by ELISA. Findings: Among five groups of mice‚ antigens in groups 1 and 2 had the highest stimulation index and group 2 showed more stimulation. Studiy of cytokine profile showed that Th1 pattern in cell-mediated immune responses to the cytoplasmic proteins of candida albicans. Conclusion: According to the results‚ cytoplasmic proteins modulate immune responses as inducers of lympho-cyte proliferation and cytokine produce in vitro. So it can be suggested as a model for vaccine. Immunotheapy with interacellular candida constituents as cytoplasmic proteins will help to inhibit the emergence of resistant candida strains and to treat fungul infections caused by chemotherapeutics after infection. Keywords: Candida albicans, Cytoplasmic proteins, Cytokine.

In this study, two techniques were used to compare the specific activity and total concentration of mycelial glutathione S-transferase (GST) in fungal strains isolated from natural sources. The fungi identified as Aspergillus parasiticus and Aspergillus flavus have been divided into two groups based on their ability to produce aflatoxins. Altogether 26 fungi were isolated, among which 12 were capable of producing varying levels of aflatoxin and 14 were proved to be non-toxigenic. GST specific activity in mycelial preparation was measured spectrophotometrically using 2,1-chloro-2,4-dinitrobenzene as the substrate. The results showed that the mean GST activity in toxigenic isolates was 25.06 +/- 9.8 micromol/mg protein/min which was 2.8-fold greater than that measured in non-toxigenic isolates (8.84 +/- 5.5 micromol/mg protein/min). Moreover, the GST concentration was compared in toxigenic and non-toxigenic isolates using an Enzyme Linked Immunosorbent Assay based on antigen (fungal preparation) and antibody (antibody produced against fungal GST in rabbit). The results of ELISA showed that the mean GST level in toxigenic and non-toxigenic fungi was 1.17 +/- 0.55 and 0.40 +/- 0.24, respectively. These results further confirm that the aflatoxin production in the fungal strains is correlated with GST expression and using ELISA, it is possible to discriminate aflatoxin-producing fungi from their non-toxigenic counterparts.

Background: Candida albicans is a pathogenic yeast that causes oral, vaginal and systemic infections. Oral candidiasis is treated with antifungal agents, particularly triazoles such as fluconazole. However, the overuse of fluconazole has resulted in the emergence of azole-resistant strains of Candida. This study tried to evaluate the sensitivity to fluconazole in strains of C. albicans clinical isolates from oral candidiasis of AIDS patients by broth microdilution and disk diffusion methods. Methods: The study included 66 C. albicans isolated from oral candidiasis of AIDS patients. C. albicans ATCC10231 was used as sensitive control and C. albicans ATCC76615 as resistant control. The minimum inhibitory concentrations (MICs) of fluconazole for all isolates were determined by broth microdilution assays for yeasts according to the clinical and laboratory standards institute (CLSI) guidelines. The MICs were evaluated after 48h of incubation at 35°C. The disk diffusion test was performed according to the procedure outlined in CLSI M44-S2 document. Mueller-Hinton agar supplemented with 2% glucose and 0.5 μg/ml of methylene blue was used and the results were read after 24h incubation at 35°C. Findings: Significant differences were not observed between broth microdilution and disk diffusion methods for evaluating the sensitivity of isolates to fluconazole. Conclusion: However, while broth microdilution is a difficult, time consuming technique, disk diffusion test is a quick and simple method for determining the sensitivity of yeasts to fluconazole.