MALDI-TOF MS characterisation, genetic diversity and antifungal susceptibility of Trichosporon species from Iranian clinical samples.

BACKGROUND: Trichosporonosis is an emerging fungal infection caused by Trichosporon species, a genus of yeast-like fungi, which are frequently encountered in human infections ranging from mild cutaneous lesions to fungemia in immunocompromised patients. The incidence of trichosporonosis has increased in recent years, owing to higher numbers of individuals at risk for this infection. Although amphotericin B, posaconazole and isavuconazole are generally effective against Trichosporon species, some isolates may have variable susceptibility to these antifungals. OBJECTIVES: Herein, we evaluated the species distribution, genetic diversity and antifungal susceptibility profiles of Trichosporon isolates in Iran. METHODS: The yeasts were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analysis was performed based on amplified fragment length polymorphism (AFLP). The in vitro susceptibilities of eight antifungal agents were analysed using the Clinical and Laboratory Standards Institute broth microdilution methods. RESULTS: The isolates belonged to the species T asahii (n = 20), T japonicum (n = 4) and T faecale (n = 3). A dendrogram of the AFLP analysis demonstrated that T asahii and non-asahii Trichosporon strains (T japonicum and T faecale) are phylogenetically distinct. While voriconazole was the most active agent (GM MIC = 0.075 µg/ml), high fluconazole MICs (8 µg/ml) were observed for a quarter of Trichosporon isolates. The GM MIC value of amphotericin B for T asahii and non-asahii Trichosporon species was 0.9 µg/ml. CONCLUSIONS: The distribution and antifungal susceptibility patterns of the identified Trichosporon species could inform therapeutic choices for treating these emerging life-threatening fungi.

Characterization of Candida species isolated from vulvovaginal candidiasis by MALDI-TOF with in vitro antifungal susceptibility profiles.

Background and Purpose: Vulvovaginal candidiasis (VVC) is an opportunistic infection due to Candida species, one of the most common genital tract diseases among reproductive-age women. The present study aimed to investigate the prevalence of VVC among non-pregnant women and identify the epidemiology of the involved Candida species with the evaluation of antifungal susceptibilities. Materials and Methods: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed to identify Candida species isolated from the genital tract of 350 non-pregnant women. Moreover, antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute broth microdilution method guidelines (M27-A3 and M27-S4). Results: Vaginal swab cultures of 119 (34%) women yielded Candida species. Candida albicans was the most frequently isolated species (68%), followed by Candida glabrata (19.2%). Voriconazole was the most active drug against all tested isolates showing an MIC50/MIC90 corresponding to 0.016/0.25 µg/mL, followed by posaconazole (0.031/1 µg/mL). Overall, resistance rates to fluconazole, itraconazole, and voriconazole were 2.4%, 4.8% and, 0.8% respectively. However, posaconazole showed potent in vitro activity against all tested isolates. Conclusion: Results of the current study showed that for the effectual therapeutic outcome of candidiasis, accurate identification of species, appropriate source control, suitable antifungal regimens, and improved antifungal stewardship are highly recommended for the management and treatment of infection with Candida, like VVC.

Epidermophyton floccosum: nucleotide sequence analysis and antifungal susceptibility testing of 40 clinical isolates.

Purpose. Epidermophyton floccosum is an anthropophilic dermatophyte species, which is one of the common causative agents of dermatophytosis in different parts of the world. The aim of the present investigation was to evaluate the genetic diversity of E. floccosum strains isolated from different parts of Iran and to define the in vitro susceptibility profiles of seven antifungal drugs against these clinical isolates.Methodology. Forty clinical strains of E. floccosum isolated from 40 patients with dermatophytosis were subjected to DNA extraction and PCR amplification of the ITS rDNA region using universal primers ITS1 and ITS4. The in vitro activities of griseofulvin, itraconazole, voriconazole, posaconazole, caspofungin, ketoconazole and terbinafine were determined using a broth microdilution method according to the CLSI-M-38A2 protocol.Results. A mean genetic similarity of 99.5 % was found between E. floccosum strains, with intraspecies differences ranging from 0 to 3 nt. The geometric mean (GM) MICs and minimum effective concentrations (MECs) across all isolates were, in increasing order, as follows: terbinafine (GM=0.018 mg l-1), posaconazole (GM=0.022 mg l-1), itraconazole (GM=0.034 mg l-1) and voriconazole (GM=0.045 mg l-1), which had low MICs against all tested strains, whereas caspofungin (GM=0.22 mg l-1), ketoconazole (GM=0.41 mg l-1) and griseofulvin (GM=0.62 mg l-1) demonstrated higher MICs.Conclusion. Our study showed low intraspecies variation within strains of E. floccosum. Furthermore, terbinafine, posaconazole, itraconazole and voriconazole were shown to be the most potent antifungal drugs against E. floccosum strains.

Unequivocal identification of an underestimated opportunistic yeast species, Cyberlindnera fabianii, and its close relatives using a dual-function PCR and literature review of published cases.

Although Cyberlindnera fabinaii is a rare opportunist yeast species, its ability to cause septicemia, produce biofilm, and rapid acquisition of resistance to fluconazole and voriconazole, reinforced the urge for its identification from its closely related species. Widely used biochemical assays mainly identify Cyberlindnera fabinaii as Cyberlindnera jadinii and Wickerhamomyces anomalus, resulting in underestimation of this yeast in clinical settings. Moreover, the urge for a reliable molecular means of identification remains unsolved for 28 years. In order to unequivocally differentiate Cy. fabianii, Cy. mississipiensis, Cy. jadinii, and W. anomalus, we designed a dual-function multiplex polymerase chain reaction (PCR) assay. Challenging our dual-function multiplex PCR assay with 30 most clinically important yeast species, proved its specificity. Although conventional PCR could differentiate four target species, the real-time PCR counterpart due to Tm overlap misidentified Cy. mississipiensis as Cy. jadinii. Alongside of presenting a comprehensive literature review of published cases of Cy. fabianii from 1990 to 2018, we collected various clinical isolates from Tehran, Shiraz, and Fasa (July 1, 2017, to December 31, 2017) to find a passive relative distribution of these closely-related species in Iran. Subjecting our Iranian collection of yeast isolates to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS and LSU and ITS rDNA sequencing revealed six isolates of Cy. fabianii (central venous catheter n = 2 and vaginal swabs n = 4) and one isolate of Cy. jadinii (vaginal swabs). Due to the use of biochemical assays in global ARTEMIS study, we encourage reidentification of clinical isolates of Cy. jadinii and Cy. jadinii using MALDI-TOF or Sanger sequencing that might lead to correcting the distribution of this fungus.

Synthesis, Antifungal Evaluation and Molecular Docking Studies of Some Tetrazole Derivatives.

A facile and simple protocol for the [3+2] cycloaddition of alkyl nitriles (RCN) with sodium azide (NaN3) in the presence of copper bis(diacetylcurcumin) 1,2-diaminobenzene Schiff base complex, SiO2-[Cu-BDACDABSBC] as a heterogeneous catalyst in the presence of ascorbic acid and a solution of water/i-PrOH (50:50, V/V) media at reflux condition is described. The supported catalyst was prepared by immobilization of a copper bis(diacetylcurcumin) 1,2-diaminobenzene Schiff base complex [Cu-BDACDABSBC] on silica gel. The complex has high selectivity, catalytic activity, and recyclability. The significant features of this procedure are high yields, broad substrate scope and simple and efficient work-up procedure. According to this synthetic methodology, excellent yields of 5-substituted 1H-tetrazoles having bioactive N-heterocyclic cores were synthesized. The in vitro antifungal activities of title compounds were screened against various pathogenic fungal strains, such as Candida species involving C. albicans, C. glabrata, C. krusei, C. parapsilosis as well as filamentous fungi like Aspergillus species consisting of A. fumigatus and A. flavus. The molecular docking analysis is discussed for one most potent compound against fungi. The docking study determined a remarkable interaction between the most potent compounds and the active site of Mycobacterium P450DM.

In vitro activity of four triazole antifungal drugs against clinically common and uncommon yeast species.

BACKGROUND AND PURPOSE: Incidence of fungal infections caused by opportunistic fungal pathogens, such as yeasts and yeast-like species, has undergone an increase in otherwise healthy individuals. These pathogens account for high mortality and show reduced susceptibility to the routine antifungal drugs. Accordingly, antifungal susceptibility testing is an urgent need in the determination of the susceptibility spectrum of antifungals and selection of appropriate antifungal agents for the management of patients with fungal infection. MATERIALS AND METHODS: The present study was conducted on 110 yeast strains belonging to 15 species recovered from clinical specimens. Susceptibility of the isolates to four antifungal drugs (i.e., fluconazole, itraconazole, voriconazole, and posaconazole) was tested according to the Clinical and Laboratory Standards Institute guidelines M27-A3 and M27-S4. RESULTS: Fluconazole exhibited no activity against 4.3% (n=2) of C. albicans isolates, whereas the remaining 44 isolates had a minimum inhibitory concentration (MIC) range of 0.125-4 µg/ml. Voriconazole had the lowest geometric mean MIC (0.03 µg/ml) against all isolated yeast species, followed by posaconazole (0.07 µg/ml), itraconazole (0.10 µg/ml), and fluconazole (0.60 µg/ml). Overall, all of the isolates had reduced voriconazole MICs with a MIC range of 0.016-0.5 µg/ml, except for one isolate of C. albicans that had a MIC of 1 µg/ml. Candida haemulonii as a multidrug-resistant fungus showed a fluconazole MIC of > 64 µg/ml. CONCLUSION: The current study provides insight into the antifungal susceptibility profiles of clinically common and uncommon yeast species to four triazole antifungal agents. According to our findings, voriconazole was the most active agent. Awareness about antifungal susceptibility patterns is highly helpful in the selection of appropriate antifungal drugs and identification of the efficiency of the currently used agents.

Increased Serum Levels of IL-17A and IL-23 Are Associated with Decreased Vitamin D3 and Increased Pain in Osteoarthritis.

INTRODUCTION: Osteoarthritis (OA) is the most common type of arthritis and proinflammatory cytokines have been considered as the main etiologic factor in the pathogenesis of the disease. Serum levels of cytokines, that are associated with innate immunity and TH1 cells, have been analyzed in OA patients, however, there is limited research that profiles cytokines associated with Th17 cells and their relation to vitamin D3 and pain. MATERIAL AND METHODS: The sera from 131 patients with OA and 262 healthy controls were evaluated for serum levels of IL-17A, IL-21, IL-23 and vitamin D3 using ELISA. RESULTS: Serum levels of IL-17A, and IL-23 were statistically higher in OA patients than in healthy controls, while IL-21 and vitamin D3 were significantly lower in OA patients when compared to controls. A significant positive correlation was found between the serum levels of IL-17A and IL-23 using WOMAC pain scores and vitamin D3 serum levels. DISCUSSION: The results suggest that IL-17A plays a significant role in OA pathogenesis and the induction of pain. Decreased serum levels of vitamin D3 may reflect a positive role played by the factor in the regulation of immune responses in OA patients.

In Vitro Activities of Six Antifungal Drugs Against Candida glabrata Isolates: An Emerging Pathogen.

BACKGROUND: Candida glabrata is a pathogenic yeast with several unique biological features and associated with an increased incidence rate of candidiasis. It exhibits a great degree of variation in its pathogenicity and antifungal susceptibility. OBJECTIVES: The aim of the present study was to evaluate the in vitro antifungal susceptibilities of the following six antifungal drugs against clinical C. glabrata strains: amphotericin B (AmB), ketoconazole (KTZ), fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), and caspofungin (CASP). MATERIALS AND METHODS: Forty clinical C. glabrata strains were investigated using DNA sequencing. The in vitro antifungal susceptibility was determined as described in clinical laboratory standard institute (CLSI) documents (M27-A3 and M27-S4). RESULTS: The sequence analysis of the isolate confirmed as C. glabrata and deposited on NCBI GenBank under the accession number no. KT763084-KT763123. The geometric mean MICs against all the tested strains were as follows, in increasing order: CASP (0.17 g/mL), VCZ (0.67 g/mL), AmB (1.1 g/mL), ITZ (1.82 g/mL), KTZ (1.85 g/mL), and FCZ (6.7 g/mL). The resistance rates of the isolates to CASP, FCZ, ITZ, VZ, KTZ, and AmB were 5%, 10%, 72.5%, 37.5%, 47.5%, and 27.5%, respectively. CONCLUSIONS: These findings confirm that CASP, compared to the other antifungals, is the potent agent for treating candidiasis caused by C. glabrata. However, the clinical efficacy of these novel antifungals remains to be determined.

Novel triazole alcohol antifungals derived from fluconazole: design, synthesis, and biological activity.

A series of new triazole alcohol antifungals were designed by replacing one of the triazolyl moiety from fluconazole with a distinct 4-amino-3-mercapto-1,2,4-triazole motif, which is found in some antimicrobial agents. The antimicrobial susceptibility testing of target compounds demonstrated that the direct analogs of fluconazole (difluorophenethyl-triazoles) were less active against fungi, while compound 10h containing dichloro substitutions on both phenyl rings of the molecule had potent activity against yeasts including Candida albicans (four strains) and Cryptococcus neoformans (MICs = 2-8 µg/mL). Also, compound 10h was active against Candida parapsilosis, Epidermophyton floccosum, and Trichophyton mentagrophytes, while it showed no activity against Gram-positive and Gram-negative bacteria. Finally, a molecular docking study suggested that compound 10h interacts suitably with lanosterol 14α-demethylase, which is the key enzyme in ergosterol biosynthesis.

Fungal Prosthetic Valve Endocarditis by Candida parapsilosis: A Case Report.

INTRODUCTION: Fungal prosthetic valve endocarditis (PVE) is rare but serious complication of valve replacement surgery. Candida species, particularly Candida albicans is the most common isolated pathogen in fungal PVE (1-6%of cases). CASE PRESENTATION: We describe a 35-year-old woman who underwent mechanical mitral valve replacement about 3 years ago. She was admitted with neurological symptoms and later with dyspnea and hypotension. Transesophageal echocardiography showed large and mobile prosthetic valve vegetation. She underwent mitral valve surgery. The explanted valve and vegetation revealed lots of budding yeasts and the isolated yeast was identified as C. parapsilosis. Amphotericin B and broad spectrum antibiotic were started immediately. Unfortunately, the patient died two days after surgery, due to sepsis probably related to the candidemia. CONCLUSIONS: Fungal endocarditis is uncommon infection, but it is a serious problem in patients with prosthetic valve. Fungal PVE can occur years after the surgery, thus long-term follow-up is essential.

Imidazolylchromanones containing non-benzylic oxime ethers: synthesis and molecular modeling study of new azole antifungals selective against Cryptococcus gattii.

A series of imidazolylchromanone oximes containing phenoxyethyl ether moiety, as found in omoconazole, were synthesized and evaluated against yeasts (Candida albicans and Cryptococcus gattii) and filamentous fungi (Aspergillus fumigatus and Exophiala dermatitidis). Although the title compounds showed marginal activity against filamentous fungi but all of them exhibited potent activity against C. gattii (MIC values ≤4 µg/mL). Among them, (3-chlorophenoxy)ethyl analog 7c with MIC value of 0.5 µg/mL was the most potent compound. Further molecular docking studies provided a better insight into the binding of designed compounds within the homology modeled active site of CnCYP51 (Cryptococcus CYP51-14α-demethylase).