Diversity of geophilic dermatophytes species in the soils of iran; the significant preponderance of nannizzia fulva

A molecular epidemiology study was conducted between 2016 and 2017 by a network of collaborators from 12 provinces in the Islamic Republic of Iran. A total of 1484 soil samples from different habitats were screened for the presence of dermatophytes by using the hair baiting technique. The primary identification of isolates was carried out by amplification and MvaI restriction fragment length polymorphism (RFLP) of the internal transcribed spacers regions of ribosomal DNA (ITS-rDNA). The identifications, especially in the cases of isolates with unknown RFLP patterns, were confirmed by sequencing of the ITS-rDNA region. As a result, 256 isolates were recovered. The isolation rate was higher in soils with pH range 7.1–8.0, collected from animal habitats (n = 78; 34%) and parks and gardens (n = 75; 32%), geographically from Mazandaran Province (n = 115; 49.5%) and seasonally in the spring (n = 129; 50.4%), all of which were statistically significant (p < 0.05). The dermatophytes comprising five species of the two genera, viz., Nannizzia fulva (n = 214), N. gypsea (n = 34), Arthroderma quadrifidum (n = 5), A. gertleri (n = 2) and A. tuberculatum (n = 1), were isolated. The geophilic dermatophytes occurred in various soils from different parts of Iran; however, surprisingly, N. fulva emerged as the dominant species, outnumbering the common geophilic species of N. gypsea. For the definitive identification of soil inhabitant dermatophytes, DNA-based identification is strongly recommended

Clinical and microbial epidemiology of otomycosis in the city of Yasuj, southwest Iran, revealing aspergillus tubingensis as the dominant causative agent

Purpose. Otomycosis is a mycotic infection of the external auditory canal and can be caused by a wide range of fungal species. In this study, we aimed to identify fungal isolates from patients suspected of otomycosis. Methodology. External ear canal samples were taken from patients referred to the outpatient department of Shahid-Mofatteh Clinic in the city of Yasuj, Iran, and examined by direct microscopy and culture. DNA of the isolated fungi was tested by internal transcribed spacer PCR restriction fragment length polymorphism analysis for identification of yeasts and β-tubulin sequencing for identification of Aspergillus species. Results. Among 275 patients suspected of otomycosis, 144 cases (83 female and 61 male) were confirmed with otomycosis. For 89% (n=128) of positive cultures, microscopy was also positive, while there were no cases with a microscopy-positive and culture-negative result. The predominant predisposing factor was self-cleaning of the external ear using unhygienic tools, and the main risk occupation was ‘housewife’. The most common isolated fungi were typically Aspergillus (n=120), including 73 isolates of Aspergillus section Nigri, 43 of section Flavi, 3 of section Terrei and 1 of section Fumigati. After sequencing, 44 out of 73 strains primarily identified as Aspergillus niger turned out to be Aspergillus tubingensis. Thirty-five isolates were identified as Candida, including Candida parapsilosis (n=22), Candida albicans (n=12) and Candida tropicalis (n=1). Conclusion. Aspergillus tubingensis was the most common species involved in otomycosis. This work corroborates the difficulty of precise identification of species within the black Aspergilli by morphological characteristics

A 9-Month-Old Girl from Iran with Extensive Erythematous Plaques Due to Trichophyton simii, a Zoophilic Dermatophyte

PubMedID: 26767834The incidence of dermatophytosis due to Trichophyton simii is generally considered to be limited to endemic areas, particularly one area of India. However, the high similarity between the morphological features of atypical T. simii isolates and those of other dermatophytes such as Trichophyton interdigitale and Arthroderma benhamiae may lead to misidentification of the cause of dermatophytosis in many instances. We investigated a rare case of tinea corporis in a 9-month-old female with extensive erythematous lesions. Morphological features of the recovered isolate from the culture resulted in the identification of Trichophyton interdigitale. For accurate identification, the internal transcribed spacer regions (ITS1 and ITS2) of the ribosomal DNA (rDNA) gene were sequenced and the isolate was ultimately identified as T. simii. In conclusion, T. simii, which has been formerly known to be restricted to specific endemic regions, appears to be not infrequent in non-endemic areas but instead simply less well-known and consequently underestimated. To determine its actual prevalence of infection, the application of DNA-based molecular methodologies is required. © 2016, Springer Science+Business Media Dordrecht

In vitro activities of five antifungal agents against 199 clinical and environmental isolates of Aspergillus flavus, an opportunistic fungal pathogen

Aspergillus flavus is the second leading cause of invasive and non-invasive aspergillosis, as well as the most common cause of fungal sinusitis, cutaneous infections, and endophthalmitis in tropical countries. Since resistance to antifungal agents has been observed in patients, susceptibility testing is helpful in defining the activity spectrum of antifungals and determining the appropriate drug for treatment. A collection of 199 clinical and environmental strains of Aspergillus flavus consisted of clinical (n = 171) and environmental (n = 28) were verified by DNA sequencing of the partial b-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MEC of caspofungin were determined in accordance with the Clinical and Laboratory Standards Institute M38-A2 document. Caspofungin, followed by posaconazole, exhibited the lowest minimum inhibitory concentrations (MIC). All isolates had caspofungin MEC90 (0.063 μg/ml) lower than the epidemiologic cutoff values, and 3.5 of the isolates had amphotericin B MIC higher than the epidemiologic cutoff values. However, their clinical effectiveness in the treatment of A. flavus infection remains to be determined. © 2016 Elsevier Masson SAS

A 9-Month-Old Girl from Iran with Extensive Erythematous Plaques Due to Trichophyton simii, a Zoophilic Dermatophyte.

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Antifungal susceptibility profile and molecular epidemiology of recurrent vulvovaginal candidiasis in Yasuj, southwestern Iran

&lt;p&gt;Candidal vaginitis is a common infection causing various clinical presentations that can also emerge as recurrent vulvovaginal candidiasis (RVVC) in many patients. Candida albicans is the most common causative agent of RVVC. Since there is no definitive guideline for RVVC treatment, it is important to consider the species and susceptibility profile of the isolate to use the appropriate antifungals. The present study was conducted to determine the prevalence of RVVC, the etiological agents, and their antifungal susceptibility among clinically suspected patients in the Yasuj region, southwest Iran. The isolated yeasts were identified based on the morphological and molecular methods followed by antifungal susceptibility testing. Overall, 65 Candida strains were isolated from RVVC samples. Candida albicans (95.4%) were the main causative agents, followed by C. glabrata (3.1%), and C. krusei (1.53%). According to our findings, 20.7% and 22.4% of Candida isolates were resistant to fluconazole (MIC≥8 μg/mL) and clotrimazole (MIC≥1 μg/mL), receptively. Although C. albicans was still the main causative agent of RVVC incidence, the importance of accurate identification of Candida strains and determination of antifungal susceptibility are emphasized. Moreover, in this study, low drug-resistance was found among isolated Candida species in Yasuj.&lt;/p&gt

In vitro antifungal activity of luliconazole, efinaconazole, and nine comparators against aspergillus and candida strains isolated from otomycosis

Background: Aspergillus and Candida species are the most commonly identified fungal pathogens in otomycosis. However, we usually encounter some difficulties in its treatment because many patients show resistance to antifungal agents and present a high recurrence rate. Objectives: The current research was conducted to compare the in vitro activities of luliconazole (LUL), and efinaconazole (EFN) and the nine comparators on Aspergillus and Candida strains isolated from otomycosis. Methods: The in vitro activities of nine common antifungal drugs (amphotericin B (AMB), voriconazole (VRC), fluconazole (FLU), itraconazole (ITC), ketoconazole (KTO), clotrimazole (CLO), nystatin (NYS), terbinafine (TRB), and caspofungin (CAS)) and two novel new azoles (LUL and EFN) against of 108 clinical isolates of Aspergillus and Candida species obtained from otomycosis were assessed according to the CLSI broth microdilution document. Results: The LUL and EFN had the geometric mean minimum inhibitory concentrations (GM MICs) of 0.098 and 0.109 µg/mL against all Aspergillus strains, respectively. Furthermore, the GM MICs of all Candida isolates for LUL, EFN, CAS, CLO, VRC, AMB, ITC, KTO, FLU, NYS, and TRB were calculated to be 0.133, 0.144, 0.194, 0.219, 0.475, 0.537, 0.655, 1.277, 4.905, 9.372, and 13.592 µg/mL, respectively. Additionally, 6 (35.29%), 2 (11.7%), and 1 (5.88%) Candida isolates were resistant to FLU, CAS, and VRC, respectively. Conclusions: As the findings indicated, LUL and EFN showed the lowest GM MIC values against the examined species. Accordingly, these novel imidazole and triazole antifungal agents can be regarded as proper candidates for the treatment of otomycosis caused by Aspergillus and Candida strain

Investigation of in vitro antifungal susceptibility testing and genetic diversity of clinical isolates of Trichophyton benhamiae and Trichophyton eriotrephon in Iran

Background: Trichophyton benhamiae is a zoophilic dermatophyte, known as one of the causative agents of dermatophytosis. Objectives: The purpose of this study was to explore the genotypes of T. benhamiae strains isolated from geographically different areas of Iran and also to evaluate in vitro antifungal susceptibility profile of these strains against seven antifungal drugs. Methods: Twenty-two strains of T. benhamiae and two strains of T. eriotrephon were isolated from patients with distinct types of dermatophytosis. DNA extraction and amplification of rDNA regions using ITS1 and ITS4 primers were conducted on the isolates. The in vitro antifungal susceptibility of posaconazole (PSC), voriconazole (VRC), itraconazole (ITC), ketoconazole (KET), caspofungin (CAS), terbinafine (TRB) and griseofulvin (GRZ) was evaluated according to CLSI M38-A2 protocol. Results: The multiple alignment of the ITS-rDNA sequences of T. benhamiae indicated a mean similarity of 99.5%, with 0–3 interspecies nucleotide difference. The geometric mean (GM) values of minimum inhibitory concentrations (MICs) and minimum effective concentrations (MECs) across the all isolates were respectively: TRB: 0.025 mg/L, PSC: 0.032 mg/L, ITC: 0.050 mg/L and VRC: 0.059 mg/L with lower values and CAS: 0.31 mg/L, KTZ: 0.56 mg/L and GRZ: 0.76 mg/L with higher values. Conclusion: Diverse ITS sequence types of T. benhamiae were shown in different geographical regions of Iran. The TRB, PSC and ITC were the most effective drugs against T. benhamiae strains, respectively. Furthermore, in our study, two strains of T. eriotrephon as a scarce dermatophyte species were described

Novel point mutations in cyp51A and cyp51B genes associated with itraconazole and posaconazole resistance in aspergillus clavatus isolates

Aspergillus clavatus is a common environmental species known to cause occupational allergic disease in grain handlers. We have recently observed azole-resistant isolates of this fungus as a cause of onychomycosis. To further characterize the cause of resistance, the genes encoding 14 α-sterol demethylase enzyme (cyp51A and cyp51B) were characterized and analyzed in 9 ITC-susceptible isolates and 6 isolates with high minimum inhibitory concentrations (MICs) of clinical (nail and sputum) and environmental A. clavatus strains. We found that six isolates with itraconazole MIC >16 mg/L demonstrated nonsynonymous mutations, including V51I, L378P, E483K, and E506G, and synonymous mutations, including F53F, A186A, Q276Q, and H359H. Moreover, P486S was detected in five strains with ITR MIC >16 mg/L. One mutation, F324S, was detected in an isolate with posaconazole MIC >16 mg/L. The effect of E483K and P486S mutations of CYP51A on azole resistance was further investigated using homology modeling and molecular dynamics. We found that E483K and P486S mutations were located near the ligand access channel of CYP51A that could partly lead to narrowing the entry of the ligand access channels. Therefore, we concluded that E483K and P486S mutations may potentially contribute to the limited access of inhibitors to the binding pocket and therefore confer resistance to azole agents. © 2019 Mary Ann Liebert, Inc., publishers