Current Medical Mycology
Volume:6 Issue: 3, Sep 2020

Aromatic waters (AWs) are therapeutic distillates, which harbor both essential oil and water-soluble components of a plant. Due to the dispersion of the light amount of essence through the AWs, they have their specific pleasant smell, taste, and medicinal properties. In Iranian traditional medicine, Trachyspermum ammi AW is used to treat gastrointestinal disorders. The present study was conducted to determine the chemical composition of the essential oil extracted from T. ammi AW and its antifungal activities against Candida species.

The composition of the essential oil extracted from T. ammi AW was analyzed by gas chromatography-mass spectrometry. In addition, the evaluation of the antifungal activity of AW against Candida species was performed using broth microdilution methods as recommended by the Clinical Laboratory Standard Institute. Moreover, the biofilm formation inhibition, antioxidant properties, and experimental activity of AW were determined in an animal model.

According to the results, thymol (78.08%) was the major compound of EO, followed by carvacrol (8.20%) and carvotanacetone (6.50%). Furthermore, T. ammi AW exhibited antifungal activities against the examined fungi and inhibited the biofilm formation of C. albicans at a concentration of up to 0.25 V/V. Histopathological analyses revealed that Candida colonization declined in the mice following the administration of T. ammi AW in a therapeutic trial.

It seems that the presence of phenolic monoterpenes in AW has resulted in antifungal effects. Pleasant odor and antioxidant properties are extra bonuses to the antimicrobial effects of this plant. Based on the findings, AW might have the potential to be used in the management of alimentary candidiasis or oral hygienic products.

The increment in fungal infections, particularly due to Candida species, is alarming due to the emergence of multidrug resistance (MDR). Hence, the identification of novel drug targets to circumvent the problem of MDR requires immediate attention. The metabolic pathway, such as glyoxylate cycle (GC), which utilizes key enzymes (isocitrate lyase [ICL] and malate synthase [MLS]), enables C. albicans to adapt under glucose-deficient conditions. This study uncovers the effect of GC disruption on the major MDR mechanisms of C. albicans as a human pathogenic fungus.

For the purpose of the study, efflux pump activity was assessed by phenotypic susceptibilities in the presence of substrates rhodamine 6G (R6G) and Nile red, along with R6G extracellular concentration (527 nm). In addition, ergosterol content was estimated by the alcoholic potassium hydroxide hydrolysis method. The estimation of chitin was also accomplished by the absorbance (520 nm) of glucosamine released by acid hydrolysis.

The results revealed that the disruption of ICL enzyme gene (Δicl1) led to the impairment of the efflux activity of multidrug transporters belonging to the ATP-binding cassette superfamily. It was further shown that Δicl1 mutant exhibited diminished ergosterol and chitin contents. In addition, all abrogated phenotypes could be rescued in the reverting strain of Δicl1 mutant.

Based on the findings, the disruption of GC affected efflux activity and the synthesis of ergosterol and chitin. The present study for the first time revealed that metabolic fitness was associated with functional drug efflux, ergosterol and chitin biosynthesis and validated GC as an antifungal target. However, further studies are needed to comprehend and exploit this therapeutic opportunity.

The search for the development of a suitable novel antimicrobial agent for fungal diseases continues to be a key problem in the current clinical field. The present investigation was aimed to determine the antifungal effect of the ethanolic crude extracts of Woodfordia fruticosa leaf (Wfl) and Punica granatum peel (Pgp) in uncontrolled diabetic patients wearing removable dentures.

The ethanolic extracts of both plants were prepared using the soxhlet extraction method, and the obtained metabolites were confirmed by thin-layer chromatography. After the preparation of the mouthwash, a total of 100 subjects were randomly divided into two groups. Each subject was given physiological saline at the baseline. Group I was provided with P. granatum mouthwash, while Group II was given W. fruticosa mouthwash. Following the administration of the mouthwash, the patients were requested to rinse the mouthwash using the oral rinse technique twice daily 5 ml/rinse for 30 sec. Subsequently, colony-forming units (CFU) were evaluated in the participants. Post-therapeutic samples were collected 1 h and 1 week after the mouthwash use.

The mean reduction of CFU was calculated at the baseline, as well as 1 h and 1 week after using mouthwash. The results indicated a drastic reduction in CFU 1 h and 1 week after the application of Wfl mouthwash.

The obtained data revealed that Wfl had potential anticandidal activity against Candida yeast cells, probably owing to its bioactive compounds like glycosides. Therefore, this agent can be used effectively as a natural remedy for the treatment of oral candidiasis. However, the exact mechanism of action of this plant needs to be elucidated.

Malassezia yeasts are lipophilic normal flora of the skin in humans and other warm-blooded vertebrates. This genus includes 18 species and is responsible for dermatological disorders, such as pityriasis versicolor, atopic dermatitis, seborrheic dermatitis, folliculitis, and dandruff. The aim of the present study was to identify the etiologic agents of Malassezia infections among the patients referring to the Referral Dermatology Clinic of Al-Zahra Hospital, Isfahan, Iran, during 2018-2019.

For the purpose of the study, clinical specimens, including skin scrapings and dandruff, were collected and subjected to direct microscopy, culture, and polymerase chain reaction (PCR) sequencing. Direct PCR was performed on the clinical samples to amplify the D1/D2 region of 26S rDNA, using specific primers; subsequently, the amplicons were sent for sequencing.

This study was conducted on 120 patients with suspected pityriasis versicolor and seborrheic dermatitis, who referred to the Referral Dermatology Clinic of Al-Zahra Hospital, Isfahan, Iran, during 2018-2019. Out of this population, 50 (41.7%), 26 (52%), and 24 (48%) cases had Malassezia infection, pityriasis versicolor, and seborrheic dermatitis, respectively. Malassezia globosa was found to be the most prevalent species (n=29, 58%), followed by M. restricta (n=20, 40%), and M. arunalokei (n=1, 2%).

The epidemiologic study was indicative of the frequency of some Malassezia species, such as M. globosa and M. restricta, in Isfahan, Iran. It can be concluded that direct PCR on clinical samples could be used as a simple, precise, effective, fast, and affordable method for research and even routine medical mycology laboratory studies.

Candida albicans is an important microorganism in the normal flora of a healthy subject; however, it has an expedient pathogenic character that induces hydrolytic virulence. Regarding this, the present study aimed to find an in vitro alternative that could reduce the virulence of this yeast.

For the purpose of the study, the effect of amphotericin B (AmB) combined with the extract of Traganum nudatum (E1) or Mentha pulegium (E2) was evaluated against the hydrolytic activities of esterase, protease, and phospholipase. This effect was determined by calculating the minimum inhibitory concentration (MIC), used to adjust the extract/AmB mixtures in culture media.

The evaluated Pz values, which corresponded to the different enzymatic activities, showed a decrease in the hydrolytic activities of C. albicans strains after the addition of E1/AmB and E2/AmB combinations at descending concentrations (lower than the obtained MICs).

Based on the findings, it would be possible to reduce the pathogenesis of this species without destabilizing the balance of the flora.

Despite advances in burn care and management, infections are still a major contributor to morbidity and mortality rates in patients with burn injuries. Regarding this, the present study was conducted to investigate the prevalence and importance of candidemia in pediatric burn patients.

Blood samples were collected from the patients and cultured in an automated blood culture system. Candida species were identified using specific culture media. The relationship between candidemia and possible risk factors was evaluated and compared to a control group.

A total of 71 patients with the mean age of 4.52±3.63 years were included in the study. Blood cultures showed candidemia in 19 (27%) patients. Based on the results, C. albicans was the most common fungus among patients with and without candidemia. The results of statistical analysis also showed that candidemia was significantly correlated with total body surface area (TBSA), mechanical ventilation, duration of total parenteral nutrition, length of intensive care unit (ICU) stay, presence of neutropenia, and R-Baux score (all P≤0.001). In this regard, TBSA, length of ICU stay, R-Baux score, and Candida score were identified as the determinant factors for mortality due to candidemia.

Candidemia increases the mortality and morbidity rates associated with burn injuries. Prompt diagnostic and prevention measures can reduce the unfortunate outcomes via controlling the possible risk factors.

Burn patients are at a higher risk of infections caused by different organisms. This study aimed to address the prevalence, causative species, and factors related to fungal colonization or infection in patients with acute severe injuries admitted to the intensive care unit (ICU) of a burn hospital in northern Vietnam.

This prospective study was conducted on 400 patients in a burn ICU between 2017 and 2019. Clinical samples were weekly collected and screened for fungi, and relevant clinical information was obtained from medical records.

According to the results, 90% of the patients were colonized with fungi. Out of this group, 12.75% of the cases had invasive fungal infection (IFI). Eleven yeasts and six mold species were isolated from the patients, with the most common species being Candida tropicalis (45.56%) and C. albicans (41.94%). Among the eleven species causing fungal wound infection (FWI), the most common agents were Candida (66.7% of FWI patients) and Aspergillus (38.5%) species. Three Candida species isolated from blood were C. tropicalis (66.7%), C. albicans (20.0%), and C. parapsilosis (14.3%). No factors were found to expose the patients to a higher risk of fungal colonization. However, hyperglycemia, prolonged ICU stay, and heavy Candida species colonization were found to be independently predictive of IFI.

Burn patients are at the risk of fungal infection with Candida species (especially C. tropicalis) and Aspergillus as the most frequently responsible agents. Continuous surveillance of fungi and appropriate management of pathophysiological consequences are essential to prevent fungal infection in burn patients.

Candida auris is an emerging multidrug-resistant pathogen. The identification of this species with the conventional phenotypic or biochemical mycological methods may lead to misidentification. Molecular-based species-specific identification methods such as quantitative real-time polymerase chain reaction (qPCR) facilitate a more reliable identification of C. auris than mycological methods. Regarding this, the present study aimed to develop a hydrolysis probe-based qPCR assay for the rapid, accurate identification of C. auris.

The internal transcribed spacer 2 regions in the nuclear ribosomal DNA of C. auris and other related yeasts were assayed to find a specific PCR target for C. auris. A 123-base-pair target was selected, and primers and a probe were designed for hydrolysis probe-based real-time PCR with TaqMan chemistry. Ten-fold serial dilutions of C. auris ranging from 106 to 100 CFU/mL were prepared to establish a standard curve to quantify the yeast.

The qPCR assay was able to identify and quantify C. auris with a detection limit of 1 C. auris CFU per reaction. Specificity was confirmed by the non-amplification of the sequences belonging to other Candida species, yeasts, molds, bacteria, or human DNAs. The standard curve of the assay showed a highly significant linearity between threshold values and dilution rates (R2=0.99; slope=−3.42).

The applied qPCR assay facilitated the rapid and accurate identification and quantification of emerging opportunistic C. auris. Therefore, considering the promising test validation results, we succeeded to develop a rapid and accurate hydrolysis probe-based qPCR assay for the screening and identification of C. auris.

Keratinophilic fungi play an important role in the decomposition of keratinous substances in nature. This capacity induces dermatomycosis in both humans and livestock. The soil of livestock stables can be a reservoir of keratinophilic fungi. Therefore, the present study was conducted to isolate and identify keratinophilic fungi in the soil of the livestock stables located in Qayen, South Khorasan Province, Iran.

This study was conducted on 62 soil samples collected from livestock stables. The samples were cultured by means of hair bait technique (HBT). The identification of the isolates was performed based on their morphological characteristics and then confirmed by polymerase chain reaction and sequencing of the ITS regions of ribosomal DNA.

A total of 118 isolates of 7 species from 5 genera were identified. Aphanoascus verrucosu (n=70, 59.36%) was detected as the dominant keratinophilic fungus, followed by Arthroderma quadrifidum (n=13, 11.01%), Aphanoascus terreus (n=12, 10.16%), Acremonium (n=12, 10.16%), Arthroderma gertleri (n=5, 4.23%), Fusarium equiseti (n=3, 2.54%), and Uncinocarpus reesii (n=3, 2.54%).

Different keratinophilic fungi were isolated from the soil of livestock stables; however, Aphanoascus verrucosu was found to be the dominant species.

Scedosporium apiospermum complex as a ubiquitous environmental mold is increasingly reported to cause an invasive fungal infection in immunosuppressive hosts. Herein, we present the case of an immunosuppressive 54-year-old man who developed S. apiospermum complex lung infection and pulmonary adenocarcinoma.

Case report: 

The patient had some complaints of dyspnea and cough during a neutropenic episode. The computed tomography (CT) scan of the patient revealed pleural effusion. After culturing the pleural fluid sample, the fungus was identified by microscopic examination and ITS sequencing. In addition, antifungal susceptibility testing was performed using the M38-A2 microdilution method. The minimum inhibitory concentrations of amphotericin B, voriconazole, posaconazole, and caspofungin were obtained as > 64, 0.06, 0.06, and 0.03 μg/mL, respectively. Voriconazole (administered in two doses of 6 mg/kg and a maximum of 250 mg) was preferred for treatment. The patient received antifungal treatment for 2 months; however, he was lost to follow-up.

Scedosporium apiospermum complex should be considered a cause of systemic fungal infections in neutropenic patients. Furthermore, the determination of the in vitro antifungal susceptibilities of clinical strains may contribute to the development of therapeutic approaches.

Rhinocladiella mackenziei is a neurotropic fungus, which can cause devastating intracerebral infections with up to 100% fatality rate. It is difficult to isolate this fungus in laboratory as it grows slowly and requires diagnostic skills.

Case report:

 A 42-year-old Pakistani man presented with headache, facial numbness, progressive upper limb weakness, and dysarthria. Magnetic resonance imaging of the brain showed a space-occupying lesion in the basal ganglia region. The patient underwent supratentorial craniotomy for biopsy and excision. Histopathology of the specimen revealed granulomatous inflammation with abscess formation. Periodic acid-Schiff special stains highlighted the presence of numerous septate fungal hyphae. The results revealed the growth of dematiaceous fungi, which were morphologically classified as R. mackenziei. The patient is currently stable and is being on amphotericin and posaconazole, along with neurorehabilitation therapy.

Rhinocladiella mackenziei brain abscess is a devastating infection with significant mortality. This condition should be suspected in patients with brain abscess from high endemic areas.

Herein, we describe a rare case of fatal cerebral phaeohyphomycosis by Cladophialophora bantiana in an immunocompetent individual without any underlying risk factors.

Case report:

 A 55-year-old female presented with a short history of fever for 1 month, as well as headache, sudden onset of right-sided upper and lower limb weakness, and loss of speech for 10 days. Contrast-enhanced magnetic resonance imaging scan revealed large, peripherally enhancing, well-defined, cystic, space-occupying, axial lesion in the left parietal lobe with a mass effect. The patient was subjected to craniotomy, and the drained pus revealed pigmented septate hyphae in potassium hydroxide mount examination, which was identified as Cladophialophora bantiana. The patient was started on amphotericin B and voriconazole. However, she developed acute respiratory infection leading to multi-organ failure and death on day 27 post-operation.

In the absence of comparative trials owing to the rarity of the disease, the radical resection of lesion, drainage of pus, and prolonged targeted antifungal therapy with close postoperative radiological surveillance are the therapeutic measures of choice for patients with brain abscess caused by phaeoid fungi.

Skin rashes, mostly seen in children and adolescents, are considered among the most common side effects of azole antifungals. Although therapeutic concentrations of voriconazole (VCZ) have been documented for infected skin, there is no evidence specifying whether specific dermatologic side effects could predict high VCZ serum concentration, especially in high-risk leukemic children.

Herein, we report a unique skin side effect of VCZ in a 5-year-old boy with T-cell acute lymphoblastic leukemia (ALL) referred to Amir Medical Oncology Center in Shiraz, Iran. The patient experienced erythroderma and macular rashes shortly after VCZ consumption, leading to generalized exfoliative skin rashes. Concurrent to these skin manifestations, VCZ serum concentration reached the supratherapeutic levels despite the recommended VCZ doses. As a result, VCZ was withheld, and the patient was treated with caspofungin. The lesions were resolved gradually within 2 weeks, and the patient successfully completed his treatment course with caspofungin.

The unique case presented in this study emphasizes the need for a high index of suspicion for VCZ toxicity in any patient with atypical dermatologic manifestations, especially generalized exfoliative skin rashes. Based on this report, VCZ supratherapeutic concentration could be predicted early in the course of treatment. Additional therapeutic dose monitoring should be considered to establish a confirmatory diagnosis. It is required to further investigate the toxic effect of high VCZ concentration on the skin epithelium.