Current Medical Mycology最新文献

Background and purpose: The main environmental saprobes, such as Penicillium, play an essential role in natural ecosystems as economically, ecologically, and medically important microorganisms. Biodiversity of this genus has not been described in Bushehr city, Iran. The present study is based on air biodiversity of Penicillium species on culture-dependent approach and culture-independent technique using partial b-tubulin sequences.

Materials and methods: By using active sampling with a high volume air sampler, a total of 157 Penicillium isolates were selected and screened for phenotypic characters. For the purposes of the study, 46 strains representative of 11 morphological species were selected and identified by molecular analysis.

Results: Based on the findings, P. crustosum (18 isolates, 39.1%) and P. chrysogenum (15 isolates, 32.6%) were the most common isolated species, followed by P. brevicompactum, P. rubens, P. citrinum, P. italicum (each 2 isolates, 4.3%), P. olsonii, P. expansum, P. griseofulvum, P. palitans, and P. polonicum (each 1 isolate, 2.1%). Except for P. chrysogenum and P. expansum with floccose colony texture, the rest of the isolated species had velutinous texture.

Conclusion: This is the first report in southern Iran to identify a large number of Penicillium strains isolated from air samples, showing P. crustosum and P. chrysogenum as the most common isolated species.

Background and purpose: Taxonomy of Candida is controversial and has changed due to the investigation of the novel species. Candida africana and Candida dubliniensis are new members of the C. albicans complex that are currently gaining both clinical and epidemiologic significance. This study aimed to report the prevalence of C. africana among the strains isolated from patients using hyphal wall protein 1 (HWP1) gene size polymorphism.

Materials and methods: In total, 235 yeasts confirmed as C. albicans complex based on chromogenic media and internal transcribed spacers sequencing isolated from various clinical forms of invasive and non-invasive candidiasis mainly candidemia were re-identified using HWP1 gene polymorphisms. The HWP1-polymerase chain reaction amplicons were re-confirmed by sequencing and BLAST analysis.

Results: Based on the HWP1 gene size polymorphism, 223 strains were identified as C. albicans (94.89%) from which 7 isolates produced two DNA fragments (850 and 941 bp). The C. dubliniensis (n=4, 1.7%), C. africana (n=1, 0.42%), and mix of C. albicans and C. africana (n=7, 2.97%) were also identified.

Conclusion: It can be said that C. albicans remains the most common Candida species, while C. dubliniensis and C. africana are rarely found among the patient isolates. Due to limited information on the molecular epidemiology of this novel yeast, more studies using molecular methods are recommended.

Background and purpose: Black Cumin of Kerman (Bunium persicum) is an Iranian plant that is commonly used as an antispasmodic, carminative, and antimicrobial substance. The present study aimed to assess different components of the essence of B. persicum and its effect on antifungal activity, spore germination inhibition, and expressions of FUM1 and FUM14 genes in Fusarium verticillioides strains.

Materials and methods: The essence was extracted by hydrodistillation and analyzed through gas chromatography-mass spectroscopy. A broth microdilution method was used for the determination of the minimum inhibitory concentration (MIC). In addition, the expression of FUM1 and FUM14 genes of toxigenic F. verticillioides was assessed by using the real-time polymerase chain reaction (RT-PCR) technique.

Results: Based on the findings, most of the essence consisted of γ-terpinene (15.56%), propanal, and 2-methyl-3-phenyl (14.18%). The oil showed a good antifungal activity (mean MIC value: 2556.8 μg/ml) as well as the inhibition of spore germination and mycelial growth (P<0.05). The RT-PCR demonstrated that the expression levels of FUM1 and FUM14 of B. persicum-treated F. verticillioides were 0.43 and 0.53 folds lower than the control samples, respectively.

Conclusion: These findings revealed that the essential oil of B. persicum has different components responsible for the inhibition of mycelial growth and spore germination of F. verticillioides as well as reduction of expressions of FUM1 and FUM14 genes involving fumonisin production.

Background and purpose: Superficial mycoses are the fourth most common cause of disease worldwide. It is not surprising that zoonotic transmission occurs to humans due to close contact with different animals, be it companion or farm animals. Therefore, the objective of this study was to determine the presence of asymptomatic dermatophyte carriers in the owner-pet pairs, identify the most common etiologic agents, and find the likely connection between the carrier status of an owner and the presence of dermatophytes in their pets.

Materials and methods: From May 2019 to January 2020, 21 cats and 115 dogs with their respective owners were selected for dermatophyte culture. All the dogs and cats included in the study were from the communities of southeastern Mexico. The samples were taken with a cotton swab, which was vigorously rubbed and twisted on the scalp or body of the pet four times and grown on Mycosel Agar. The isolates were identified based on macroscopic and microscopic characteristics. The prevalence of the binomial ranged from 0.73% in pet skin and human hands to 2.2% in human scalp. In humans, the agents were Trichophyton tonsurans and Trichophyton verrucosum, while in pets, a strain of Trichophyton sp was found.

Conclusion: Different species of dermatophytes were found in the owner/pet pairs, which denotes that coexistence is not related in asymptomatic cases.

Background and purpose: Coronavirus disease 2019 (COVID-19) and Candida prostatic valve endocarditis present various clinical manifestations which may overlap; hence, discrimination between them is extremely difficult.

Case report: The case was a 66-year-old man with a past medical history of mitral and aortic valves replacement one year before COVID-19 co-infection. He was admitted with fever (for 7 days), shortness of breath, cough, seizure, lethargy, headache, and 85% oxygen saturation. Transesophageal echocardiography revealed multiple large-sized, highly mobile masses on both sides of the mechanical mitral valve highly suggestive of vegetation. Chest computed tomography scanning showed simulating scattered COVID-19 peripheral ground-glass opacities confirmed by reverse-transcription polymerase chain reaction. The set of blood cultures yielded yeast colonies that were identified as Candida tropicalis. The patient died of septic shock shortly after receiving antifungal therapy.

Conclusion: This case emphasized the importance of early diagnosis and implementation of antifungal treatment, particularly in patients with prosthetic cardiac valves, to reduce their unfavorable outcomes in COVID-19 patients.

Background and purpose: Amphotericin B (AmB) is the standard treatment for systemic fungal infections; however, the formation of reactive oxygen species reduces the efficacy and stability of this molecule. The present study aimed to evaluate the effect of the combination of AmB with ascorbic acid and α-tocopherol on its autoxidation and antifungal activity.

Materials and methods: The antifungal activity against Candida albicans was evaluated by the viable cell counting method and checking their morphological changes with a scanning electron microscope. Monomer state of AmB was assessed by scanning the UV absorbance in the range of 300-450 nm and the lipid peroxidation was measured using quantification of thiobarbituric acid reactive-substances (TBARS).

Results: Based on the findings, the addition of ascorbic acid (3×10² µg/mL) and α-tocopherol (16 µg/mL) to the reaction medium of AmB increased its antifungal  activity while maintaining its molecular stability. Moreover, the level of TBARS formed in the reaction medium of AmB was significantly reduced after combination  with ascorbic acid and α-tocopherol.

Conclusion: Given their availability, their anti-free radical activity, and their low toxicity, the incorporation of ascorbic acid and α-tocopherol into the reaction medium of AmB seems to be a promising approach to obtain an effective antifungal formulation.

Background and purpose: Because of the growing incidence of Aspergillus infection, typing methods of Aspergillus species are increasingly being used. Accordingly, studying the spread and population dynamics of strains isolating from clinical and environment, from a single host to large-scale ecosystems is definitely needed. In the current study, we carried out a genetic analysis of nine microsatellite loci in isolates from different regions of Iran to compare and explore the genetic diversity between environmental and clinical A. fumigatus strains.

Materials and methods: Sixty-six clinical (n=43) and environmental (n= 23) isolates of A. fumigatus, have collected from six cities of Iran. All A. fumigatus isolates identified based on macroscopic and microscopic characters, the ability to grow at above 45°C, and confirmed using DNA sequencing of the partial b-tubulin gene. Sixty-six A. fumigatus isolates were subjected by microsatellite typing using three separate multiplex PCRs with a panel of nine short tandem repeats (STR) to evaluate the genetic relatedness.

Results: The STR typing of 66 A. fumigatus isolates revealed 38 distinct genotypes distributed among environmental and clinical isolates. We identified 12 clones including 40 different isolates representing 60% of all isolates tested, which each clone included 2-7 isolates.

Conclusion: The STR typing is considered as a valuable tool with excellent discriminatory power to study the molecular epidemiology and genotypic diversity of A. fumigatus isolates. These findings show that the high genetic diversity observed of Iranian A. fumigatus isolates with those outside Iran and formed a separate cluster.

Cutaneous fungal infections are the fourth most common health problem, which involves approximately one billion people worldwide. Drug delivery to the skin seems to be the best choice for superficial fungal infections. Topical formulations can release a sufficient amount of drug in therapeutical concentrations and permeate higher layers of the skin like the stratum corneum. As the outermost layer of the epidermis, the stratum corneum prevents the drug from penetrating the skin. Liposomes, especially nanosized as topical drug delivery systems to the skin, can show various functions depending on their size, lipids and cholesterol components, the percent of ingredients, lamellarity, and surface charge. Nanoliposomes can increase permeation through the stratum corneum, decrease systemic effects with their localizing actions, and overcome many dermal drug delivery obstacles. Antifungal drugs, such as croconazole, econazole, fluconazole, ketoconazole, terbinafine hydrochloride, tolnaftate, and miconazole entrapped in liposomes have indicated improved skin penetration and localizing effects. According to the literature review summarized in this paper, many studies have identified liposomes as a powerful carrier for topical antifungal drug delivery to the skin. However, a few studies introduced new generations of liposomes like ethosomes and transfersomes. This paper was conducted on almost all liposomal studies of antifungal drugs with dermal application.

Background and purpose: Radiation therapy in patients with head and neck malignancies predisposes them to oral Candida colonization and infection due to damage of oral mucosa and destruction of the salivary gland. This study aimed to determine the prevalence of oropharyngeal candidiasis (OPC) in patients with head and neck cancer (HNC) undergoing radiotherapy (RT), identify the yeasts isolated from them, and determine their antifungal susceptibility.

Materials and methods: This cross-sectional study was conducted from December 2018 to June 2019 at two referral radiotherapy centers in northern Iran. Yeast strains that were isolated from patients with HNC were identified using conventional and molecular methods. The in vitro activities of eight common antifungal drugs against 55 isolates were investigated according to the guidelines of the Clinical and Laboratory Standard Institute (M27-A3 and M27-S4) broth microdilution document.

Results: Among 59 patients receiving RT, the prevalence of OPC was 21 (35.59%) and 15 (25.42%) patients were diagnosed with colonization. The mean age of the patients was 55.32±13.3 years (within the range of 27-87 years). In this study, the pseudomembranous form was reported as the most clinical type of OPC. Candida albicans with the frequency of 60% was the most common type of Candida spp. that was observed in this study, although non-albicans Candida spp., such as C. glabrata (27.27%), C. tropicalis (5.45%), C. parapsilosis (3.63%), C. krusei (1.83%), and C. kefyr (1.83%) were also isolated. Considering the low minimum inhibitory concentration range of amphotericin B, compared to fluconazole, administration of this agent is a more suitable antifungal drug for extensive oral candidiasis in these patients. Among azoles, clotrimazole had low efficacy and several studied isolates (65.5%) showed resistance.

Conclusion: Correct diagnosis as well as determining drug sensitivity and risk factors are the effective steps in reducing the complications related to oral candidiasis in people undergoing RT.

Background and purpose: There has been a significant increase in the burden of fungal diseases in the last few decades which has imposed a global threat to the health of humans, animals, and plants. Epidemiology of fungal diseases is not completely understood in Africa. Most of these diseases are under-reported or not reported at all mainly due to the challenges related to the availability of and access to fungal diagnostics and the lack of human resources in clinical and diagnostic mycology across the continent. Therefore, it is imperative to highlight the epidemiology of the endemic and epidemic of emerging and re-emerging fungal diseases as well as their diagnostic challenges in Africa based on the available data. Moreover, it is important to underline the existing gaps in this regard as well.

Materials and methods: For the purposes of the study, Medline and Google Scholar were searched to retrieve articles on these prominent fungal diseases, as well as their etiologies and available diagnostics.

Results: It was found that histoplasmosis and other AIDS-associated mycoses have been reported in Africa, including blastomycosis, coccidioidomycosis, and paracocci-dioidomycosis. Other reported infections were fungal neglected tropical diseases, especially sporotrichosis, dermatophytosis, mycetoma, and chromoblastomycosis as well as emerging fungal diseases, such as Emergomyces africanus, Candida auris, and Blastomyces emzantsi. In Africa, the major drivers of fungal diseases include human immunodeficiency infection, tuberculosis, and poverty.

Conclusion: Serious fungal diseases are common in Africa; however, the true burden remains unknown.