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Background and Purpose: Candida parapsilosis complex isolates are mainly responsible for nosocomial catheter-related infection in immunocompromised patients. Biofilm formation is regarded as one of the most pertinent key virulence factors in the development of these emerging infections. The present study aimed to compare in vitro antifungal susceptibility patterns and biofilm-related genes expression ratio in planktonic and biofilm’s cells of clinically C. parapsilosis complex isolates. Materials and Methods: The current study was conducted on a number of 17 clinical C. parapsilosis complex (10 C. parapsilosis sensu stricto, 5 C. orthopsilosis, and 2 C. metapsilosis). The antifungal susceptibility patterns of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin in planktonic and biofilm forms were closely examined using CLSI M27-A3 broth microdilution method. The expression levels of biofilm-related genes (BCR1, EFG1, and FKS1) were evaluated in planktonic and biofilm’s cells using Real-time polymerase chain reaction (PCR) technique. Results: The obtained results indicated that all C. parapsilosis complex isolates were able to produce high and moderate amounts of biofilm forms. In addition, the sessile minimum inhibitory concentrations were reported to be high for fluconazole (≥ 64 μg/ml), itraconazole, voriconazole, and posaconazole (≥ 16 μg/ml), as compared to planktonic minimum inhibitory concentrations. Moreover, a significant difference was observed between antifungal susceptibility patterns for all azole antifungal agents (P Conclusion: C. parapsilosis complex isolates were found susceptible to most of the tested antifungal drugs, while biofilms demonstrated a noticeable resistant to azoles. The marked discrepancy noted in antifungal susceptibility patterns among these species should be highlighted to achieve effective therapeutic treatment.

Candida parapsilosis is one of the main emerging non-Candida albicans species leading to superficial and systemic fungal infections in humans. Candida has the ability to produce biofilms associated with pathogenesis. The aim of the study was to estimate biofilm-producing ability of clinical isolates of C. parapsilosis sp. complex.Clinical samples of C. parapsilosis complex have been analyzed. Crystal violet (CV) staining and tetrazolium reduction assay (MTT) have been used to analyze the clinical isolates ability to produce biofilms. The biofilm's structural characteristics have been assessed by using scanning electron microscopy.All 65 isolates were able to form biofilm. In addition, no significant difference was found between biofilm quantification based on two assays at different time intervals (24h, 48h, 72h, 96h) (P0.05), with the exception of Candida orthopsilosis, which exhibited higher metabolic activity at 24h time point (P0.05). Moreover, metabolic activity and production of biofilm biomass demonstrated statistically significant correlation (r=0.685, P0.01). According to microscopic observations, the investigated clinical strains formed the similar surface topography with the slight differences in morphology; in addition, there was no statistically significant difference between efficiency of two assays to quantify biofilm.It was shown that, similar to C. parapsilosissensu stricto, two cryptic identified species (C. orthopsilosis and Candida metapsilosis) obtained from different clinical samples, were biofilm producers, while C. parapsilosissensu stricto exhibited the highest biofilm production.

Background and Purpose: Aspergillus flavus is an important pathogen in immunodeficient patients. Due to the abundance of this fungus in nature, fungicides are commonly used to preserve and maintain agricultural products. Long-term exposure to these pesticides can lead to the induction of drug resistance in this fungus. Materials and Methods: For the purpose of the study, 10 strains of A. flavus ATCC 204304 were cultured in benomyl and diazinon pesticides at the concentrations of 62.5, 125, 250.500, 750, 1000, 1500, 2000, and 2500 mg/L in nine steps. Morphological changes and resistance to voriconazole, itraconazole, and amphotericin B were evaluated at the end of each step. Subsequently, changes in the expression of mdr1 and cyp51C genes were studied in the strains showing drug resistance. Results: The results showed that during the nine stages of the adjacency of strains with benomyl and diazinon at different concentrations, resistance to voriconazole, itraconazole, and amphotericin B in these toxins increased by 30% and 10%, respectively. In addition, the microscopic examination of resistant strains revealed the absence of sporulation, and only mycelium was found. Macroscopically, the color of the colonies changed from green to white. Furthermore, the investigation of the expression of mdr1 and cyp51c genes in these strains showed a decrease and increase in adjacency with diazinon and benomyl, respectively. Conclusion: As the findings indicated, exposure to agricultural pesticides can lead to the incidence of morphological changes and resistance to amphotericin B, itraconazole, and voriconazole in the sensitive species of A. flavus by altering the expression of genes involved in drug resistance.

Background and Purpose: Candida parapsilosis complex isolates are mainly responsible for nosocomial catheter-related infection in immunocompromised patients. Biofilm formation is regarded as one of the most pertinent key virulence factors in the development of these emerging infections. The present study aimed to compare in vitro antifungal susceptibility patterns and biofilm-related genes expression ratio in planktonic and biofilm’s cells of clinically C. parapsilosis complex isolates. Materials and Methods: The current study was conducted on a number of 17 clinical C. parapsilosis complex (10 C. parapsilosis sensu stricto, 5 C. orthopsilosis, and 2 C. metapsilosis). The antifungal susceptibility patterns of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin in planktonic and biofilm forms were closely examined using CLSI M27-A3 broth microdilution method. The expression levels of biofilm-related genes (BCR1, EFG1, and FKS1) were evaluated in planktonic and biofilm’s cells using Real-time polymerase chain reaction (PCR) technique. Results: The obtained results indicated that all C. parapsilosis complex isolates were able to produce high and moderate amounts of biofilm forms. In addition, the sessile minimum inhibitory concentrations were reported to be high for fluconazole (≥ 64 µg/ml), itraconazole, voriconazole, and posaconazole (≥ 16 µg/ml), as compared to planktonic minimum inhibitory concentrations. Moreover, a significant difference was observed between antifungal susceptibility patterns for all azole antifungal agents (P

Background and Purpose: Candida parapsilosis is a predominant species found in nosocomial infection, particularly in hospitalized patients. The molecular epidemiology of the clinical strains of this species has not been well studied. The present study was performed with the aim of investigating the microsatellite genotyping of Candida parapsilosis among the Iranian clinical isolates. Materials and Methods: This study was conducted on 81 independent clinical C. parapsilosis isolates that were genotyped by using a panel of six microsatellite markers. Results: The short tandem repeat (STR) typing of clinical C. parapsilosis isolates demonstrated 68 separate genotypes, among which 57 genotypes were observed once and the remaining 11 cases were identified for multiple times. The Simpson’s diversity index for the panel of combined six markers yielded a diversity index of 0.9951. The heterogeneity was observed among the Iranian and the Netherlands clinical C. parapsilosis isolates. Conclusion: As the findings indicated, the clinical C. parapsilosis isolates from Iran showed a high genetic diversity. It can be concluded that molecular epidemiology could be useful for screening during outbreak investigation where C. parapsilosis is involved.&nbsp

Background and Purpose: Aspergillus fumigatus is one of the most common opportunistic fungus, which causes infection in immunocompromised and neutropenic patients. The current guidelines recommend voriconazole as the initial therapeutic and prophylactic agent for almost all cases, especially in patients with organ transplants, which leads to increased medication resistance in A. fumigatus. The aim of the present study was to evaluate the antifungal activity and effect of kombucha as a natural compound on A. fumigatus growth, as well as on the expression of cgrA and cyp51A genes. Materials and Methods: A panel of 15 A. fumigatus strains with two quality controls of CM237 and CM2627 as susceptible and resistant strains were obtained from Tehran Medical Mycology Laboratory, Tehran,Iran(TMML).Antifungal susceptibility testing assay was performed according to the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. Moreover, the mycelial dry weight of the fungus was calculated before and after being treated with kombucha. In addition, the quantitative changes in the expression of cgrA and cyp51A genes were analyzed by real-time polymerase chain reaction (real-time PCR) technique. Results: In the present study, the minimum inhibitory concentration ranges of kombucha were measured at 6,170 and 12,300 μg/mL for ten A. fumigatus azole-susceptible strains and 24,700 μg/mL for five A. fumigatus resistant strains. Moreover, changes in mycelial dry weight under kombucha treatment conditions underwent a significant reduction (P≤0.05). A coordinate down-regulation of expression in cgrA and cyp51A genes was observed in all azole-susceptible and -resistant A. fumigatus strains, after treating the fungus with different concentrations of kombucha (P≤0.05). Conclusion: According to the obtained results, kombucha as a natural antioxidant , can exert inhibitory effects against the growth and expression of some genes in A. fumigatusstrains.

Objective Candida parapsilosis species complex, an important set of non-albicans Candida species, is known to cause candidaemia particularly in neonates and infants. However, the incidence has increased in recent years, owing to higher numbers of at individuals at risk for these infections. Our objective was to evaluate the in vitro susceptibility of clinical isolates of C. parapsilosis complex isolates from Iran to seven antifungal drugs. Material and methods One hundred-one clinical isolates of C. parapsilosis species complex cultured from humans were included. Species identification had been previously confirmed by combined phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry-based assay and reconfirmed by DNA sequence analysis of the ITS rDNA region and D1/D2 gene. Minimum inhibitory concentrations (MICs) for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, micafungin and anidulafungin were determined against well-characterized isolates by broth microdilution susceptibility testing according to the CLSI M27-A3 guideline. Results Species identifications were performed on 101 isolates, of which 88 (87.2%) C. parapsilosis sensu stricto and 13 (12.8%) C. orthopsilosis. Amphotericin B and posaconazole were the most active drugs with 100% of isolates being wild-type (WT). Voriconazole and micafungin, 99% of isolates were WT. The low activity was recorded for fluconazole and itraconazole with 93.1% and 89.1% of isolates being WT, respectively. At the species level, all Candida parapsilosis sensu stricto isolates were WT to amphotericin B and posaconazole and all Candida orthopsilosis isolates were WT to amphotericin B, voriconazole, posaconazole, anidulafungin and micafungin. In contrast, the highest rate of non-WT was observed in C. orthopsilosis to itraconazole (4 of 13, 30.8%). Conclusions Although almost all of the tested drugs demonstrated potent activity against C. parapsilosis species complex, it seems that more especially C. orthopsilosis isolates had decreased susceptibility to itraconazole. Further studies are needed to determine how these findings may switch into in vivo efficacy.