Evaluation of antifungal activity of natural compounds on growth and aflatoxin B1 production of Aspergillus parasiticus and Aspergillus flavus

BACKGROUND

Aspergillus species cause broad spectrum infections especially invasive lethal infections in immunocompromised patients. This study aimed to assess the antifungal activity of plants and compounds including Aloe vera, Thyme, carvacrol, and nano-encapsulation of carvacrol on the growth and production of aflatoxin B1 production by Aspergillus parasiticus and Aspergillus flavus.

METHODS AND RESULTS

Minimum inhibitory concentrations of extracts Aloe vera, Thyme, carvacrol, and nanocarvacrol, and fluconazole as a control were determined according to Clinical and Laboratory Standards Institute by serial microdilution protocol. Then, the effect of inhibitory concentrations of these compounds on the aflatoxin B1 production level was evaluated by real-time PCR and high-performance liquid chromatography. Our results indicate that the Aspergillus parasiticus and Aspergillus flavusare sensitive to selected plants and compounds.

CONCLUSION

Our findings showed that the compounds are appropriate alternative candidates against growth and production of aflatoxin of Aspergillus spp.

Antifungal activity of green-synthesized curcumin-coated silver nanoparticles alone and in combination with fluconazole and itraconazole against Candida and Aspergillus species

Background and Purpose

Regarding the wide-spectrum antimicrobial effects of curcumin and silver, this study aimed to evaluate the antifungal activity of green-synthesized curcumin-coated silver nanoparticles (Cur-Ag NPs) against a set of Candida and Aspergillus species.

Materials and Methods

Cur-Ag NPs were synthesized by mixing 200 µL of curcumin solution (40 mM) and 15 mL of deionized water. The mixture was stirred for 3-5 min, followed by the addition of 2.5 mL of silver nitrate solution (2.5 mM). The resulting solution was incubated for 3 days. Antifungal susceptibility of 30 fungal isolates of Aspergillus and Candida to fluconazole and itraconazole, as well as the activity of Cur-Ag NPs against the isolates, were determined, both alone and in combination, using broth microdilution according to the Clinical and Laboratory Standards Institute guidelines.

Results

Cur-Ag NPs demonstrated promising antifungal activity, particularly against Candida species. The geometric mean value of the minimum inhibitory concentration of Cur-Ag NPs was significantly lower than that of fluconazole for all the studied fungi. Similarly, it was lower than those of itraconazole in C. albicans and A. fumigatus. The minimum fungicidal concentrations of Cur-Ag NPs were markedly better than those of fluconazole but still inferior to those of itraconazole.

Conclusion

Cur-Ag NPs demonstrated indisputable antifungal activity and great potential that can be harnessed to combat fungal infections, particularly those caused by azole-resistant strains of Aspergillus and Candida.

Biomaterials with antifungal strategies to fight oral infections

Oral fungal infections pose a threat to human health and increase the economic burden of oral diseases by prolonging and complicating treatment. A cost-effective strategy is to try to prevent these infections from happening in the first place. With this purpose, biomaterials with antifungal properties are a crucial element to overcome fungal infections in the oral cavity. In this review, we go through different kinds of biomaterials and coatings that can be used to functionalize them. We also review their potential as a therapeutic approach in addition to prophylaxis, by going through traditional and alternative antifungal compounds, e.g., essential oils, that could be incorporated in them, to enhance their efficacy against fungal pathogens. We aim to highlight the potential of these technologies and propose questions that need to be addressed in prospective research. Finally, we intend to concatenate the key aspects and technologies on the use of biomaterials in oral health, to create an easy to find summary of the current state-of-the-art for researchers in the field.

Oral candidiasis in patients with kidney transplantation in Iran: prevalence and antifungal susceptibility pattern

Aim: This study aimed to identify Candida species recovered from the oral cavity of patients with kidney transplantation. Materials & methods: Two swabs were taken from the oral cavities of 40 patients before and after transplantation, cultured on Sabouraud dextrose agar, and yeasts identified. Antifungal drug susceptibility testing was performed with fluconazole and itraconazole. Results: Candida glabrata was the most frequently isolated species in patients, followed by Candida albicans and Rhodotorula. C. glabrata isolates from patients before transplantation were resistant to fluconazole, whereas C. albicans was fluconazole-resistant both before and after transplantation. Conclusion: The importance of non-albicans Candida species in the oral cavity of patients sheds light on performing antifungal tests for achieving the best outcome to prevent therapeutic failure.

Thymoquinone Antifungal Activity against Candida glabrata Oral Isolates from Patients in Intensive Care Units-An In Vitro Study

The number of Candida spp. infections and drug resistance are dramatically increasing worldwide, particularly among immunosuppressed patients, and it is urgent to find novel compounds with antifungal activity. In this work, the antifungal and antibiofilm activity of thymoquinone (TQ), a key bioactive constituent of black cumin seed Nigella sativa L., was evaluated against Candida glabrata, a WHO 'high-priority' pathogen. Then, its effect on the expression of C. glabrata EPA6 and EPA7 genes (related to biofilm adhesion and development, respectively) were analyzed. Swab samples were taken from the oral cavity of 90 hospitalized patients in ICU wards, transferred to sterile falcon tubes, and cultured on Sabouraud Dextrose Agar (SDA) and Chromagar Candida for presumptive identification. Next, a 21-plex PCR was carried out for the confirmation of species level. C. glabrata isolates underwent antifungal drug susceptibility testing against fluconazole (FLZ), itraconazole (ITZ), amphotericin B (AMB), and TQ according to the CLSI microdilution method (M27, A3/S4). Biofilm formation was measured by an MTT assay. EPA6 and EPA7 gene expression was assessed by real-time PCR. From the 90 swab samples, 40 isolates were identified as C. glabrata with the 21-plex PCR. Most isolates were resistant to FLZ (n = 29, 72.5%), whereas 12.5% and 5% were ITZ and AMB resistant, respectively. The minimum inhibitory concentration (MIC₅₀) of TQ against C. glabrata was 50 µg/mL. Importantly, TQ significantly inhibited the biofilm formation of C. glabrata isolates, and EPA6 gene expression was reduced significantly at MIC₅₀ concentration of TQ. TQ seems to have some antifungal, antibiofilm (adhesion) effect on C. glabrata isolates, showing that this plant secondary metabolite is a promising agent to overcome Candida infections, especially oral candidiasis.

Combination of Farnesol with Common Antifungal Drugs: Inhibitory Effect against Candida Species Isolated from Women with RVVC

Background and Objectives: Vulvovaginal candidiasis (VVC) is a mucous membrane infection, with an increased rate of antifungal resistance of Candida species. In this study, the in vitro efficacy of farnesol alone or in combination with traditional antifungals was assessed against resistant Candida strains recovered from women with VVC. Materials and Methods: Eighty Candida isolates were identified by multiplex polymerase chain reaction (PCR), and the antifungal susceptibility to amphotericin B (AMB), fluconazole (FLU), itraconazole (ITZ), voriconazole (VOR), clotrimazole (CTZ), and farnesol was tested by the standard microdilution method. The combinations of farnesol with each antifungal were calculated based on the fractional inhibitory concentration index (FICI). Result: Candida glabrata was the predominant species (48.75%) isolated from vaginal discharges, followed by C. albicans (43.75%), C. parapsilosis (3.75%), a mixed infection of C. albicans and C. glabrata (2.5%) and C. albicans and C. parapsilosis (1%). C. albicans and C. glabrata isolates had lower susceptibility to FLU (31.4% and 23.0%, respectively) and CTZ (37.1% and 33.3%, respectively). Importantly, there was "synergism" between farnesol-FLU and farnesol-ITZ against C. albicans and C. parapsilosis (FICI = 0.5 and 0.35, respectively), reverting the original azole-resistant profile. Conclusion: These findings indicate that farnesol can revert the resistance profile of azole by enhancing the activity of FLU and ITZ in resistant Candida isolates, which is a clinically promising result.

Enhancing of Wound Healing in Burn Patients through Candida albicans β-Glucan

The mortality and disability-adjusted life years (DALYs) of burn patients are decreasing over time. However, finding novel effective treatment approaches using natural agents is highly considered to reduce the burden of burn injuries. One of the recent agents used in wound healing is β-glucan, mainly extracted from fungi cell walls. This study aimed to evaluate the effect of 5% (m/m) of yeast β-glucan ointment on burn wound healing and to assess the impact of β-glucan on cytokines during the treatment. Thirty-three patients with second or third-degree burns were enrolled in this study. Two groups of twenty-three and ten patients used yeast 5% (m/m) β-glucan ointment (study group) and Stratamed ointment (control), respectively, on a daily basis, for a maximum of four weeks. The size of the burn wounds was measured before and at the end of the treatment. Blood samples of 14 and 10 patients in the β-glucan and control groups, respectively, were obtained before and after the treatment, and the enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum concentration of the IL-4, IL-17, and IFN-γ cytokines. The log-binomial model was used to assess the efficacy of the β-glucan ointment on burn wound healing. ANOVA/ANCOVA was employed to assess the effects of β-glucan on the serum concentration of cytokines. After adjusting for potential confounders/covariates, patients receiving β-glucan had better wound healing (RR = 4.34; 95% CI: 0.73 to 25.67; p = 0.11). There was a significant difference in IL-4 secretion between the β-glucan and control groups after adjusting for potential confounders/covariates (MD = 77.27; 95% CI: 44.73 to 109.82; Cohen’s d = 2.21; 95% CI: 1.16 to 3.24; p = 0.0001). The results indicate that 5% (m/m) of β-glucan has efficacy in burn wound healing, and a significant difference was found in the level of IL-4 after receiving β-glucan. Further studies with a two-arm design and long-term use of ointment are needed to confirm the effect of β-glucan on wound healing and cytokine secretion.

Biofilm formation in clinically relevant filamentous fungi: a therapeutic challenge

Biofilms are highly-organized microbial communities attached to a biotic or an abiotic surface, surrounded by an extracellular matrix secreted by the biofilm-forming cells. The majority of fungal pathogens contribute to biofilm formation within tissues or biomedical devices, leading to serious and persistent infections. The clinical significance of biofilms relies on the increased resistance to conventional antifungal therapies and suppression of the host immune system, which leads to invasive and recurrent fungal infections. While different features of yeast biofilms are well-described in the literature, the structural and molecular basis of biofilm formation of clinically related filamentous fungi has not been fully addressed. This review aimed to address biofilm formation in clinically relevant filamentous fungi.

A High Rate of Recurrent Vulvovaginal Candidiasis and Therapeutic Failure of Azole Derivatives Among Iranian Women

Recurrent vulvovaginal candidiasis (RVVC) is one of the most prevalent fungal infections in humans, especially in developing countries; however, it is underestimated and regarded as an easy-to-treat condition. RVVC may be caused by dysbiosis of the microbiome and other host-, pathogen-, and antifungal drug-related factors. Although multiple studies on host-related factors affecting the outcome have been conducted, such studies on Candida-derived factors and their association with RVVC are lacking. Thus, fluconazole-tolerant (FLZT) isolates may cause fluconazole therapeutic failure (FTF), but this concept has not been assessed in the context of Candida-associated vaginitis. Iran is among the countries with the highest burden of RVVC; however, comprehensive studies detailing the clinical and microbiological features of this complication are scarce. Therefore, we conducted a 1-year prospective study with the aim to determine the RVVC burden among women referred to a gynecology hospital in Tehran, the association of the previous exposure to clotrimazole and fluconazole with the emergence of FLZT and fluconazole-resistant (FLZR) Candida isolates, and the relevance of these phenotypes to FTF. The results indicated that about 53% of the patients (43/81) experienced RVVC. Candida albicans and C. glabrata constituted approximately 90% of the yeast isolates (72 patients). Except for one FLZT C. tropicalis isolate, FLZR and FLZT phenotypes were detected exclusively in patients with RVVC; among them, 27.9% (12/43) harbored FLZR strains. C. albicans constituted 81.2% of FLZR (13/16) and 100% of the FLZT (13/13) isolates, respectively, and both phenotypes were likely responsible for FTF, which was also observed among patients with RVVC infected with fluconazole-susceptible isolates. Thus, FTF could be due to host-, drug-, and pathogen-related characteristics. Our study indicates that FLZT and FLZR isolates may arise following the exposure to over-the-counter (OTC) topical azole (clotrimazole) and that both phenotypes can cause FTF. Therefore, the widespread use of OTC azoles can influence fluconazole therapeutic success, highlighting the necessity of controlling the use of weak topical antifungals among Iranian women.

Candida auris: A Quick Review on Identification, Current Treatments, and Challenges

Candida auris is a novel and major fungal pathogen that has triggered several outbreaks in the last decade. The few drugs available to treat fungal diseases, the fact that this yeast has a high rate of multidrug resistance and the occurrence of misleading identifications, and the ability of forming biofilms (naturally more resistant to drugs) has made treatments of C. auris infections highly difficult. This review intends to quickly illustrate the main issues in C. auris identification, available treatments and the associated mechanisms of resistance, and the novel and alternative treatment and drugs (natural and synthetic) that have been recently reported.

Does alternation of Candida albicans TUP1 gene expression affect the progress of symptomatic recurrent vulvovaginal candidiasis?

Background and Purpose

Recurrent vulvovaginal candidiasis (RVVC) is one of the most common gynecological conditions in healthy and diabetic women, as well as antibiotic users. The present study was conducted to determine the relationship between TUP1 gene expression patterns and symptomatic recurrent C. albicans infections.

Materials and Methods

This research was performed on C. albicans samples isolated from the vaginal specimens obtained from 31 individuals with RVVC in 2016. The reference strain C. albicans ATCC 10231, 10 C. albicans strains isolated from minimally symptomatic patients, and 10 isolates from asymptomatic patients were also used as control strains. The relative mRNA expression of the TUP1 gene was quantified using quantitative real-time polymerase chain reaction (QRT-PCR).

Results

The QRT-PCR results revealed that TUP1 mRNA expression was significantly decreased (0.001-0.930 fold) in the C. albicans isolates obtained from RVVC patients (P<0.001). However, no TUP1 expression was detectable in the isolates collected from asymptomatic patients. The results also indicated a significant correlation between TUP1 mRNA expression level and the severity of itching and discharge (P<0.001).

Conclusion

The present results were suggestive of the probable contribution of TUP1, as a part of the transcriptional repressor, to the severity of the symptoms related to C. albicans infections in the vagina. Regarding this, it is required to perform more in vivo studies using a larger sample size to characterize the regulatory or stimulatory function of TUP1 in the severity of RVVC symptoms. Furthermore, the study and identification of the genes involved in the severity of the symptomatic manifestations of C. albicans, especially in resistant strains, may lead to the recognition of an alternative antifungal target to enable the development of an effective agent.

Low prevalence of antifungal resistant Candida africana, in the C. albicans complex causing vulvovaginal candidiasis

The Candida (C.) albicans complex includes C. albicans, C. dubliniensis, C. stellatoidea, and C. africana, with the last mentioned as an important emerging agent of vulvovaginal candidiasis (VVC). The aim of the study was to identify C. africana and C. dubliniensis and assess their drug susceptibility in vaginitis. One-hundred Candida isolates of the C. albicans complex from women diagnosed with vaginitis and from vaginal samples in the culture collection of a medical mycology laboratory were examined. Species of the C. albicans complex were identified with conventional and molecular methods using polymerase chain reaction (PCR) for amplification and sequencing of the internal transcribed spacer (ITS) region, PCR for partial amplification of hyphal wall protein 1 (HWP1) gene and duplex PCR. The effects of antifungal drugs were evaluated according to standard broth microdilution protocols.

Ninety-seven C. albicans (97%) and three C. africana (3%) isolates were identified. Results of susceptibility testing revealed one isolate of C. africana to be resistant to both clotrimazole and fluconazole, and one showed reduced susceptibility to itraconazole.

Identification of Candida species especially C. africana in vaginitis is crucial, there are varying levels of resistance to antifungal drugs.

Candida albicans Beta-Glucan Induce Anti- Cancer Activity of Mesenchymal Stem Cells against Lung Cancer Cell Line: An In-Vitro Experimental Study

OBJECTIVE

β-glucan, glucopyranosyl polymers of fungi cell wall, represent an immune stimulating effects with potential anti-cancer activity. Mesenchymal stem cells (MSC) have immunomodulating properties in cancer microenvironment. The aim of this study was to investigate the anti-cancer effect of Candida albicans (C. albicans) beta-glucan on MSCs supernatant for apoptosis assay of lung cancer cells in vitro.

METHODS

Beta-glucan was extracted from cell wall of C.albicans. MSC isolated from adipose tissue of patients and confirmed using specific surface markers expression which examined by flow cytometry. MSCs treated with various concentrations of β-glucans for 48 hours. Cytotoxic effect of β-glucans was evaluated using MTT assay. MSC and lung cancer line cocultured and treated with β-glucans and apoptosis assay was done by flow cytometry.

RESULTS

Cytotoxicity findings showed a significant decrease in MSC viability during 48h, however it was dose-dependent (P<0.05). According to the obtained findings, supernatant of mesenchymal stem cells treated with β-glucans increased cancer cells apoptosis (P<0.05).

CONCLUSION

Beta glucan may highlight a potential and novel promising candidate in future strategies to cause apoptosis of cancer cells and consider as therapeutic  agent against tumor growth as well. Definitely, more in vitro and in vivo studies are required to understand its functions.

Antifungal effects of indolicidin-conjugated gold nanoparticles against fluconazole-resistant strains of Candida albicans isolated from patients with burn infection

Background:Candida albicans as an opportunistic fungus is one of the most important causes of late-onset morbidity and mortality in patients with major burns and severely impaired immune system. In recent years, the emergence of resistance to opportunistic fungi and toxicity of antimicrobial drugs make it necessary to develop new drugs.

Methods: In the present study, we investigated anticandidal effects of indolicidin, as a representative of host defense peptide, conjugated with gold nanoparticles in fluconazole-resistant clinical isolates of C. albicans. After characterizing the conjugation of indolicidin using biophysical methodologies, the cytotoxicity and hemolytic activity of the nanocomplex were examined. In addition, the expression level of ERG11, responsible for antifungal resistance, and the immunomodulatory effect of peptide-nanomaterial conjugates were assessed.

Results: Our data indicated that the nanocomplex was nontoxic for the fibroblast cells and erythrocytes. Treatment with the nanocomplex significantly reduced the expression levels of the ERG11 gene in fluconazole-resistant C. albicans isolates and the iNOS gene in macrophages.

Conclusion: The study data provides a chance to develop innovative therapies for the treatment of C. albicans burn infections. However, further investigation is required to examine the efficiency of the nanocomplex.

Incidence and spectrum of yeast species isolated from the oral cavity of Iranian patients suffering from hematological malignancies

Background: Oral candidiasis (OC) has a profound effect on the life quality of immunocompromised patients, such as those undergoing chemotherapy. Objective: Systematic investigation of clinical outcome and microbiological features of yeast isolates recovered from the oral cavity of 150 Iranian patients with hematological malignancies. Design: MALDI-TOF MS, 21-plex PCR, and rDNA sequencing were used for identification. Antifungal susceptibility testing (broth microdilution, CLSI M27-A3/S4) and genotypic diversity of yeast isolates (amplified fragment length polymorphism) were assessed. Results: Nystatin treatment resulted in 70% therapeutic failure and administration of 150 mg fluconazole (FLZ) + nystatin for patients with OC relapse showed 70% clinical failure. Previous history of OC was significantly correlated with FLZ treatment requirement and nystatin failure (P = 0.005, α < 0.05). Candida albicans (80.3%) and Kluyveromyces marxianus (C. kefyr) (12.7%) were the two most prevalent yeast species isolated. FLZ and AMB exhibited the highest geometric mean values. 21-PCR showed 98.9% agreement with MALDI-TOF MS. K. marxianus isolates had the same genotype, while C. albicans isolates grouped in 15 genotypes. Conclusions: Marked rate of therapeutic failure of nystatin necessitated OC treatment with systemic antifungals. K. marxianus was the second most prevalent yeast and 21-plex PCR could be considered as an inexpensive identification tool.

Molecular characterization and antifungal susceptibility testing of Candida nivariensis from blood samples - an Iranian multicentre study and a review of the literature

PURPOSE

Identification of the emerging yeast species Candida nivariensis among presumptively identified Iranian Candida glabrata isolates.

METHODOLOGY

Clinical C. glabrata species complex isolates from blood (n=71; 33.3 %), urine (n=100; 46.9 %), vaginal swabs (n=20;9.4 %), BAL (n=10; 4.7 %), and sputum (n=12; 5.6 %) from Iran were investigated. Isolates were characterized by CHROMagar, multiplex PCRs, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), amplified fragment length polymorphism (AFLP) fingerprinting, internal transcribed spacer (ITS)/large subunit (LSU) rDNA and FKS1/FKS2 sequencing, and the European Committee on Antimicrobial Susceptibility Testing broth microdilution method. A comprehensive literature review was conducted and all the relevant clinical and microbiological data were collected.

RESULTS

Four C. nivariensis isolates were recovered from blood samples of three subjects and were all consistently identified by nine-plex PCR, Bruker MALDI-TOF MS, and LSU and ITS rDNA sequencing. AFLP genotyping clustered the isolates into two groups. Sequencing of the FKS1 and FKS2 hotspots showed no accountable amino acid substitutions. All isolates were susceptible to amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin and micafungin.

CONCLUSION

In total, 4 out of 213 clinical C. glabrata species complex candidemia isolates were C. nivariensis. Improvement of the BioMerieux Vitek MS database is required to accurately identify C. nivariensis and it is advised to alternatively use CHROMagar and/or PCR-based techniques. As other species within the Nakaseomyces clade may cause infection and showed high MIC values for antifungals, inclusion of their spectra into the MALDI-TOF MS database seems relevant. Due to developing resistance to fluconazole and insufficient efficacy of caspofungin, the combination of catheter removal plus treatment with caspofungin, or voriconazole, or micafungin might be effective for patients.

A new formulation of graphene oxide/fluconazole compound as a promising agent against Candida albicans

Candida albicans (C. albicans) belongs to the opportunistic fungal pathogens, which cause a wide spectrum of infections in immune-compromised patients. Graphene oxide (GO), a biocompatibility agent, has been reported to exhibit effective antimicrobial activity. In the present study, a graphene oxide/fluconazole (GO/Flu) compound was synthesized and characterized using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The antifungal activity of GO/Flu was examined against fluconazole-resistant C. albicans (ATCC 10231) compared to GO and Flu using the broth microdilution method, according to CLSI protocol. DNA fragmentation was assessed through the antifungal mechanism of GO/Flu. The release of Fluin PBS medium was measured. Moreover, the cytotoxicity effect of GO/Flu on SW480 cell line was evaluated. Indeed, adhesion ability of C. albicans-treated GO/Flu against SW480 cell line was assessed. The minimum inhibitory concentration (MIC) of GO, Flu, and GO/Flu was determined at 800 µg/mL, 16 µg/mL, and 400-9 µg/mL, respectively. Notably, GO/Flu exhibited an intense antifungal activity compared to GO and Flu. In addition, GO/Flu showed much less cell toxicity against SW480 cell line than GO and Flu (P < 0.05). The release determination of Flu in PBS (pH 7.4) medium was 72.42%. GO/Flu reduced the adhesion ability of C. albicans to SW480 cell line significantly. DNA fragmentation assay indicated that GO/Flu potentially degraded the DNA of C. albicans and caused a fungicidal influence. According to the findings, GO/Flu could enhance the antifungal activity against C.albicans through DNA fragmentation with low cytotoxicity effect.

Comparison of 21-Plex PCR and API 20C AUX, MALDI-TOF MS, and rDNA Sequencing for a Wide Range of Clinically Isolated Yeast Species: Improved Identification by Combining 21-Plex PCR and API 20C AUX as an Alternative Strategy for Developing Countries

Occurrence of non-Candida albicans Candida (NCAC) species that are associated with elevated MIC values and therapeutic failures are increasing. As a result, timely and accurate means of identification to the species level is becoming an essential part of diagnostic practices in clinical settings. In this study, 301 clinically isolated yeast strains recovered from various anatomical sites [Blood (n = 145), other sites (n = 156)] were used to assess the accuracy and practicality of API 20C AUX and 21-plex PCR compared to MALDI-TOF MS and large subunit rDNA (LSU rDNA). MALDI-TOF MS correctly identified 98.33% of yeast isolates, 100% of top five Candida species, 95.7% of rare yeast species, while 1.3% of isolates were misidentified. API 20C AUX correctly identified 83.7% of yeast isolates, 97.2% of top five Candida species, 61.8% of rare yeast species, while 16.2% of yeast isolates were misidentified. The 21-plex PCR, accurately identified 87.3% of yeast isolates, 100% of top five Candida species, 72% of rare yeast species, but it misidentified 1.3% of rare yeast species while 9.9% of whole yeast isolates were not identified. The combination of rapidity of 21-plex PCR and comprehensiveness of API 20C AUX, led to correct identification of 92% of included yeast isolates. Due to expensiveness of MALDI-TOF MS and sequencing, this combination strategy could be the most accurate and inexpensive alternative identification strategy for developing countries. Moreover, by the advent and development of cost-effective, reliable, and rapid PCR machines that cost 130 US dollars, 21-plex could be integrated in routine laboratories of developing and resource-limited countries to specifically identify 95% causative agents of yeast-related infections in human. Databases of MALDI-TOF MS, API 20C AUX, and the number of target species identified by 21-plex require further improvement to keep up with the diverse spectrum of yeast species.

Synthesis, characterization and antifungal activity of a novel formulated nanocomposite containing Indolicidin and Graphene oxide against disseminated candidiasis

OBJECTIVE

Candidiasis is one of the most opportunistic fungal infections in immunocompromised patients. The emergence of multidrug-resistant Candida species necessitates the development of novel antifungal agents. Seeking to the discovery of natural antifungal agents, this study aimed to synthesize a novel formulated nanocomposite containing Indolicidin (IN), antimicrobial peptide, and Graphene oxide (GO), kind of nanomaterial, against Candida growth using in vitro and in vivo experiments for the first time.

METHODS

The formulated nanocomposite (GO-IN) synthetized and was characterized using scanning electron microscopy, X-ray power diffraction, and fourier transform infrared method analysis. The in vitro antifungal activity of fluconazole (FLU), GO, IN, and GO-IN was determined against Candida albicans (C. albicans) compared to control groups, cell cytotoxicity assay on human intestinal epithelial cells (IEP) and hemolytic activities were performed. Moreover, in vivo experiments of nanocomposite were assessed in BALB/c mice.

RESULTS

Our results showed that nanocomposite had the highest inhibitory effect against C. albicans (MIC 3.12μg/mL) compared with flu (MIC 4μg/mL), IN (MIC 12.5μg/mL), and GO (MIC 6.25μg/mL). Viability of human intestinal cell line at the MIC concentration (3.12μg/mL) of nanocomposite (GO-IN) was detected as 60% (P<0.05). The results of hemolytic activity showed that nanocomposite cause 2.73% of red blood cell membrane damage. For in vivo experiments, infected mice were successfully treated with GO-IN once a day within 7 days. GO-IN treated group eliminated the Candida infection in the spleen and liver of BALB/c mice (P=0.001) similar to fluconazole. There was no significant difference in histological manifestations between flu and GO-IN groups.

CONCLUSION

This study suggests that synergistic combination of GO and IN provide a new option, representing a potential therapeutic efficiency against disseminated candidiasis in an animal model as well as might be used as adjunct therapy in the management of candidiasis. However, further investigation is needed to evaluate the efficacy of the nanocomposite.

Iranian HIV/AIDS patients with oropharyngeal candidiasis: identification, prevalence and antifungal susceptibility of Candida species

Oropharyngeal candidiasis is the commonest mucocutaneous infection in HIV-positive individuals. Herein, samples were taken from oral cavities of 150 HIV-infected patients and cultured on Sabouraud-dextrose agar; 89 (59·3%) of 150 patients had positive culture for Candida and presented clinical sign of classical oral candidiasis. Totally, 102 morphologically distinct colonies were isolated from Candida positive cultures and subsequently identified by polymerase chain reaction and sequencing assay, presenting the following frequency: 54 C. albicans (52·9%), 16 C. dubliniensis (15·7%), 12 C. tropicalis (11·8%), 9 C. glabrata (8·8%), 7 C. kefyr (6·9%) and 4 C. africana (3·9%). Additionally, multiple Candida species were co-isolated from 13·5% (12/89) patients. Regarding the antifungal susceptibility test, which was performed by CLSI protocol (M27-A3/M27-S3), all Candida isolates were susceptible to amphotericin B and caspofungin, while some of them were resistant to fluconazole (17·6%; 16 C. albicans, 1 C. dubliniensis and 1 C. glabrata), itraconazole (16·7%; 15 C. albicans, 1 C. dubliniensis and 1 C. tropicalis) and voriconazole (5·9%; 5 C. albicans and 1 C. tropicalis). Collectively, our findings reinforce the urgent necessity to find new therapeutic agents to treat oral candidiasis in HIV-positive patients, especially due to the high incidence of azole-resistant Candida strains and the increased frequency of non-C. albicans species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The Candida species recovered from oral cavity of 150 Iranian HIV/AIDS patients and their antifungal susceptibility profiles were reported. Candida albicans was the commonest Candida species, followed by C. dubliniensis, C. tropicalis, C. glabrata, C. kefyr and C. africana. All Candida isolates were susceptible to amphotericin B and caspofungin, while resistance to azoles was detected. The growing drug-resistance profile reported in clinical isolates of C. albicans and non-C. albicans strains is a serious problem in hospitals worldwide. Consequently, the suitable antifungal choice to treat the HIV/AIDS population with oral candidiasis needs to be rethought and new therapeutic options must urgently arise.

What are the advantages of living in a community? A microbial biofilm perspective!

Biofilm formation is the preferred mode of growth lifestyle for many microorganisms, including bacterial and fungal human pathogens. Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces. Microbial biofilms cause problems in the hospital environment, generating high healthcare costs and prolonged patient stay, which can result in further secondary microbial infections and various health complications. Consequently, both public and private investments must be made to ensure better patient management, as well as to find novel therapeutic strategies to circumvent the resistance and resilience profiles arising from biofilm-associated microbial infections. In this work, we present a general overview of microbial biofilm formation and its relevance within the biomedical context.

Azole-Resistance in Aspergillus terreus and Related Species: An Emerging Problem or a Rare Phenomenon?

Objectives: Invasive mold infections associated with Aspergillus species are a significant cause of mortality in immunocompromised patients. The most frequently occurring aetiological pathogens are members of the Aspergillus section Fumigati followed by members of the section Terrei. The frequency of Aspergillus terreus and related (cryptic) species in clinical specimens, as well as the percentage of azole-resistant strains remains to be studied.

Methods: A global set (n = 498) of A. terreus and phenotypically related isolates was molecularly identified (beta-tubulin), tested for antifungal susceptibility against posaconazole, voriconazole, and itraconazole, and resistant phenotypes were correlated with point mutations in the cyp51A gene.

Results: The majority of isolates was identified as A. terreus (86.8%), followed by A. citrinoterreus (8.4%), A. hortai (2.6%), A. alabamensis (1.6%), A. neoafricanus (0.2%), and A. floccosus (0.2%). One isolate failed to match a known Aspergillus sp., but was found most closely related to A. alabamensis. According to EUCAST clinical breakpoints azole resistance was detected in 5.4% of all tested isolates, 6.2% of A. terreus sensu stricto (s.s.) were posaconazole-resistant. Posaconazole resistance differed geographically and ranged from 0% in the Czech Republic, Greece, and Turkey to 13.7% in Germany. In contrast, azole resistance among cryptic species was rare 2 out of 66 isolates and was observed only in one A. citrinoterreus and one A. alabamensis isolate. The most affected amino acid position of the Cyp51A gene correlating with the posaconazole resistant phenotype was M217, which was found in the variation M217T and M217V.

Conclusions:Aspergillus terreus was most prevalent, followed by A. citrinoterreus. Posaconazole was the most potent drug against A. terreus, but 5.4% of A. terreus sensu stricto showed resistance against this azole. In Austria, Germany, and the United Kingdom posaconazole-resistance in all A. terreus isolates was higher than 10%, resistance against voriconazole was rare and absent for itraconazole.

Differential role of gpaB and sidA gene expressions in relation to virulence in Aspergillus species from patients with invasive aspergillosis

The virulence genes in invasive aspergillosis (IA) have not been analyzed adequately. The present study was designed to evaluate the expression of gpaB and sidA genes, which are important virulence genes in Aspergillus spp. from bronchoalveolar lavage (BAL) samples. Direct examination and culture on Czapek Agar and Sabouraud Dextrose Agar media were performed for 600 BAL specimens isolated from patients with possible aspergillosis. A Galactomannan ELISA assay was also carried out. The expression levels of the gpaB and sidA genes in isolates were analyzed using quantitative real-time PCR (qRT-PCR). We identified 2 species, including Aspergillus flavus (A. flavus) and Aspergillus fumigatus (A. fumigatus) in 25 positive samples for invasive aspergillosis as validated using GM-ELISA. A. flavus is the main pathogen threatening transplant recipients and cancer patients worldwide. In this study, A. flavus had low levels of the gpaB gene expression compared to A. fumigatus (p = 0.006). The highest sidA expression was detected in transplant recipients (p = 0.05). There was no significant correlation between sidA expression and underlying disease (p = 0.15). The sidA and gpaB gene expression patterns may provide evidence that these virulence genes play important roles in the pathogenicity of Aspergillus isolates; however, there are several regulatory genes responsible for the unexpressed sidA and gpaB genes in the isolates.

Antimicrobial Peptides As Biologic and Immunotherapeutic Agents against Cancer: A Comprehensive Overview

Antimicrobial peptides (AMPs) are a pervasive and evolutionarily ancient component of innate host defense which is present in virtually all classes of life. In recent years, evidence has accumulated that parallel or de novo mechanisms by which AMPs curb infectious pathologies are also effective at restraining cancer cell proliferation and dissemination, and have consequently stimulated significant interest in their deployment as novel biologic and immunotherapeutic agents against human malignancies. In this review, we explicate the biochemical underpinnings of their tumor-selectivity, and discuss results of recent clinical trials (outside of oncologic indications) which substantiate their safety and tolerability profiles. Next, we present evidence for their preclinical antitumor activity, systematically organized by the major and minor classes of natural AMPs. Finally, we discuss the barriers to their clinical implementation and envision directions for further development.

Lung cancer and β-glucans: review of potential therapeutic applications

The potential of natural substances with immunotherapeutic properties has long been studied. β-glucans, a cell wall component of certain bacteria and fungi, potentiate the immune system against microbes and toxic substances. Moreover, β-glucans are known to exhibit direct anticancer effects and can suppress cancer proliferation through immunomodulatory pathways. Mortality of lung cancer has been alarmingly increasingly worldwide; therefore, treatment of lung cancer is an urgent necessity. Numerous researchers are now dedicated to using β-glucans as a therapy for lung cancer. In the present attempt, we have reviewed the studies addressing therapeutic effects of β-glucans in primary and metastatic lung cancer published in the time period of 1991-2016.

Overexpression of MDR-1 and CDR-2 genes in fluconazole resistance of Candida albicans isolated from patients with vulvovaginal candidiasis

Background and Purpose:

Candida albicans (C. albicans) is an opportunistic fungus that can colonize women’s mucosal epithelial cell surfaces, causing vulvovaginitis in specific circumstances. The major genes contributing to drug resistance in C. albicans are the candida drug resistance (CDR) and multi drug resistance (MDR) genes. The purpose of this study was to evaluate the CDR-2 and MDR-1 gene expression patterns in C. albicans strains isolated from patients with recurrent vulvovaginal candidiasis.

Materials and Methods:

In this study, 40 isolates of fluconazole-resistant C. albicans were cultured on Sabouraud dextrose agar. These isolates were collected from women with vulvovaginitis who were referred to a clinic in Tehran, Iran, and transferred to a mycology laboratory. Then, RNA was extracted from the isolates using phenol-chloroform and glass beads, and the complementary DNA (cDNA) was synthetized. To detect the semi-quantitative expression of CDR-2 and MDR-1 genes, the reverse transcriptase-PCR (RT-PCR) technique was performed using specific primers.

Results:

Our findings indicated that of the 40 C. albicans isolates, 35 (87.5%) strains were positive for mRNA of the CDR-2 gene, 32 (80%) strains expressed mRNA of the MDR-1 gene, and 30 (75%) strains were confirmed to express mRNA of both the CDR-2 and MDR-1 genes simultaneously using the RT-PCR assay.

Conclusion:

According to the obtained results, the expression rates of CDR-2 and MDR-1 genes were high in fluconazole-resistant C. albicans isolates, which can cause treatments to fail and result in chronic infections. Inhibiting these important genes using novel or natural agents can help with the treatment of chronic and recurrent vaginitis.

Antifungal effect of Echinophora platyloba on expression of CDR1 and CDR2 genes in fluconazole-resistant Candida albicans

BACKGROUND

Several studies examined the effect of the Echinophora platyloba extract in treatment of azole-resistant Candida albicans clinical isolates.

OBJECTIVE

We investigated the effect of E. platyloba extract on expression of CDR1 and CDR2 genes in fluconazole-resistant clinical isolates of C. albicans using real-time PCR.

MATERIALS AND METHODS

The crude extract of E. platyloba was obtained using percolation method. Using serial dilution method, different concentrations of extract were achieved. Two hundred microlitres of fungal suspension (10(6) CFU/ml) was added to the media and cultured with different concentrations and then incubated at 37 °C for 48 h. The concentration of extract in the first tube, which inhibited the growth of C. albicans, was recorded as the Minimal Inhibitory Concentration (MIC). In order to analyse the expression of CDR1 and CDR2 genes, RNA was extracted from C. albicans isolates before and after treatment with MIC of E. platyloba using glass beads and the denaturing buffer agents in an RNase-free environment and then the cDNA was synthesised and used for real-time PCR assay.

RESULTS

Twenty of total of 148 isolates were resistant to fluconazole. The MIC and MFC for the alcoholic extract of E. Platyloba were 64 mg/ml and 128 mg/ml, respectively. Real-time PCR results revealed that the mRNA levels of CDR1 and CDR2 genes significantly declined after incubation with E. Platyloba (both p values < 0.001).

CONCLUSION

E. Platyloba is effective in reducing CDR1 and CDR2 expression which in turn plays an important role in fluconazole resistance in Candida species.

ALS1 and ALS3 gene expression and biofilm formation in Candida albicans isolated from vulvovaginal candidiasis

BACKGROUND

A cluster of genes are involved in the pathogenesis and adhesion of Candida albicans to mucosa and epithelial cells in the vagina, the important of which is agglutinin-like sequence (ALS) genes. As well as vaginitis is a significant health problem among women, the antifungal resistance of Candida species is continually increasing. This cross-sectional study investigates the expression of ALS1 and ALS3 genes and biofilm formation in C. albicans isolate isolated from vaginitis.

MATERIALS AND METHODS

Fifty-three recognized isolates of C. albicans were collected from women with recurrent vulvovaginal candidiasis in Iran, cultured on sabouraud dextrose agar, and then examined for gene expression. Total messenger RNA (mRNA) extracted from C. albicans isolates and complementary DNA synthesized using reverse transcriptase enzyme. Reverse transcription-polymerase chain reaction (RT-PCR) using specific primer was used to evaluate the expression of ALS1 and ALS3 through housekeeping (ACT1) genes. 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to assess adherence capacity and biofilm formation in the isolated.

RESULTS

Forty isolates (75.8%) expressed ALS1 and 41 isolates (77.7%) expressed ALS3 gene. Moreover, 39 isolates (74%) were positive for both ALS1 and ALS3 mRNA by the RT-PCR. Adherence capability in isolates with ALS1 or ALS3 genes expression was greater than the control group (with any gene expression), besides, it was significantly for the most in the isolates that expressed both ALS1 and ALS3 genes simultaneously.

CONCLUSION

The results attained indicated that there is an association between the expression of ALS1 and ALS3 genes and fluconazole resistance in C. albicans. A considerable percent of the isolates expressing the ALS1 and ALS3 genes may have contributed to their adherence to vagina and biofilm formation.

The First Case of Total Dystrophic Onychomycosis Caused by Aspergillus clavatus Resistant to Antifungal Drugs

Onychomycosis is a common fungal infection of nails which is mainly caused by dermatophyte species and less often by yeasts and non-dermatophyte molds. We present a case of onychomycosis due to Aspergillus clavatus for the first time worldwide. The patient was an immunocompetent 32-year-old woman who identified with Psoriasis of the nail. The presence of A. clavatus in a nail sample was confirmed using microscopic and culture analysis followed by PCR of the β-tubulin gene. After antifungal susceptibility test, it is revealed that the isolate was resistant to the majority of common antifungal drugs, but finally the patient was treated with itraconazole 200 mg daily. A. clavatus and drug-resistant A. clavatus have not previously been reported from onychomycosis.

Fluconazole Resistance Candida albicans in Females With Recurrent Vaginitis and Pir1 Overexpression

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.

Immunomodulatory Effect of β-Glucan on Peritoneal Macrophages of Bab1/c Mice

We assessed the effect of β-Glucan on macrophages by Griess reagent and viability by MTT assay and cytotoxicity. Assay of macrophages culture supernatants were carried out on WEHI-164 fibrosarcoma cell line as tumor necrosis factor-α bioassay were done. NO release was increased at the dose of 10 µg/ml (P = 0.001) of β-Glucan while the viability of macrophages in all concentrations was the same. In TNF-α bioassay, the supernatant of macrophages stimulated with β-Glucan had a significant cytotoxic effect on WEHI-164 cells (P = 0.023). β-Glucan had a positive effect on increasing tumoricidal activity of macrophages which may help in anti-cancer immune responses.

The effects of Candida albicans cell wall protein fraction on dendritic cell maturation

BACKGROUND

Candida albicans is a member of the normal human microflora. C. albicans cell wall is composed of several protein and carbohydrate components which have been shown to play a crucial role in C. albicans interaction with the host immune system. Major components of C. albican cell wall are carbohydrates such as mannans, beta glucans and chitins, and proteins that partially modulate the host immune responses. Dendritic cells (DC), as the most important antigen-presenting cells of the immune system, play a critical role in inducing immune responses against different pathogens.

OBJECTIVE

We investigated the effect of the cell wall protein fraction (CPF) of C. albicans on DC maturation.

METHODS

The CPF of C. albicans cells was extracted by a lysis buffer containing sodium dodecyl sulphate, 2-mercaptoethanol and phosphate-buffered saline. The extract was dialyzed and its protein pattern was evaluated by electrophoresis. Dendritic cells were purified from Balb/c mice spleens through a three-step method including mononuclear cell separation, as well as 2-h and overnight cultures. The purified CPF was added at different concentrations to DC. The purity and maturation status of DC were determined by flow cytometry using monoclonal antibodies against CD11c, MHC-II, CD40 and CD86.

RESULTS

Treatment of DC with 10 microg/ml of CPF increased the expression of maturation markers including MHC-II, CD86 and CD40 on DC compared to the control group.

CONCLUSION

In this study we used C. albicans CPF with the molecular weight of 40-45 kDa for pulsing and maturation of dendritic cells. Since according to our results CPF significantly increased the expression of maturation markers on DC, we suggest that CPF may act as an efficient immunomodulator, or may be used as a potential adjuvant to boost the host immune system against infections.