Iranian National Survey on Tinea Capitis: Antifungal Susceptibility Profile, Epidemiological Characteristics, and Report of Two Strains with a Novel Mutation in SQLE Gene with Homology Modeling.

BACKGROUND: The data on the epidemiological and antifungal susceptibility profile of tinea capitis (TC) in Iran has not been updated in recent decades. This report presents the Iranian epidemiological and drug susceptibility data regarding the distribution of dermatophytes species isolated by six national mycology centers for a period of one year (2020-2021). MATERIAL AND METHODS: A total of 2100 clinical samples from individuals suspeted to TC were subjected to mycological analysis of direct microscopy and culture. For definite species identification, the culture isolates were additionally subjected to PCR-RFLP and PCR-sequencing of the ITS ribosomal DNA (ITS-rDNA) region. Antifungal susceptibility profiles for eight common antifungal drugs were determined by CLSI M38-A3 guidelines. The SQLE gene was partially amplified and sequenced in two terbinafine-resistant and two susceptible T. mentagrophytes isolates to elucidate probable substitutions involved in resistance. RESULTS: TC (n = 94) was diagnosed in 75 children (79.8%) and 19 adults (20.2%) by direct microscopy and culture. Frequency of TC was significantly more among males (66 males = 70.2% vs 28 females = 29.8%). The prevalent age group affected was 5-9 years (39.36%). Thirty-two (34.04%) T. mentagrophytes, 27 (28.7%) T. tonsurans, 14 (14.9%) M. canis, 13 (13.8%) T. violaceum, 5 (5.32%) T. indotineae, 2 (2.1%) T. benhamiae, and 1 (1.1%) T. schoenleinii were identified as the causative agents. MIC values of isolates showed susceptibility to all antifungal agents, except for fluconazole and griseofulvin with GM MIC of 11.91 µg/ml and 2.01 µg/ml, respectively. Terbinafine exhibited more activity against isolates, with GM MIC 0.084 µg/ml followed by ketoconazole (0.100 µg/ml), econazole (0.107 µg/ml), itraconazole (0.133 µg/ml), butenafine (0.142 µg/ml), and miconazole (0.325 µg/ml). Two resistant T. mentagrophytes isolates harbored missense mutations in SQLE gene, corresponding to amino acid substitution F397L. Remarkably, one unique mutation, C1255T, in the SQLE sequence of two terbinafine-susceptible T. mentagrophytes strains leading to a change of leucine at the 419th position to phenylalanine (L419F) was detected. CONCLUSIONS: T. mentagrophytes, T. tonsurans, and M. canis remained the main agents of TC in Iran, however less known species such as T. indotinea and T. benhamiae are emerging as new ones. Terbinafine could still be the appropriate choice for the treatment of diverse forms of TC.

Indoor environment assessment of special wards of educational hospitals for the detection of fungal contamination sources: A multi-center study (2019-2021).

Background and Purpose: The hospital environment was reported as a real habitat for different microorganisms, especially mold fungi. On the other hand, these opportunistic fungi were considered hospital-acquired mold infections in patients with weak immune status. Therefore, this multi-center study aimed to evaluate 23 hospitals in 18 provinces of Iran for fungal contamination sources. Materials and Methods: In total, 43 opened Petri plates and 213 surface samples were collected throughout different wards of 23 hospitals. All collected samples were inoculated into Sabouraud Dextrose Agar containing Chloramphenicol (SC), and the plates were then incubated at 27-30ºC for 7-14 days. Results: A total of 210 fungal colonies from equipment (162, 77.1%) and air (48, 22.9%) were identified. The most predominant isolated genus was Aspergillus (47.5%), followed by Rhizopus (14.2%), Mucor (11.7%), and Cladosporium (9.2%). Aspergillus (39.5%), Cladosporium (16.6%), as well as Penicillium and Sterile hyphae (10.4% each), were the most isolates from the air samples. Moreover, intensive care units (38.5%) and operating rooms (21.9%) had the highest number of isolated fungal colonies. Out of 256 collected samples from equipment and air, 163 (63.7%) were positive for fungal growth. The rate of fungal contamination in instrument and air samples was 128/213 (60.1%) and 35/43 (81.2%), respectively. Among the isolated species of Aspergillus, A. flavus complex (38/96, 39.6%), A. niger complex (31/96, 32.3%), and A. fumigatus complex (15/96, 15.6%) were the commonest species. Conclusion: According to our findings, in addition to air, equipment and instrument should be considered among the significant sources of fungal contamination in the indoor environment of hospitals.

Optimization of the antifungal metabolite production in Streptomyces libani isolated from northern forests soils in Iran.

BACKGROUND AND PURPOSE: Soil bacteria have extreme population diversity among natural sources and are able to produce a wide array of antifungal metabolites. This study aimed to isolate and identify the bioactive metabolite-producing bacteria from forest soils and evaluate their antimicrobial potent against some pathogenic organisms. MATERIALS AND METHODS: In this study, soil samples were screened for antifungal activity against Aspergillus fumigatus on glucose-yeast extract (GY) agar using a visual agar plate assay method. All growing bacteria were examined for antifungal activity, and antagonistic bacteria were identified based on 16S ribosomal RNA sequence analysis. For optimization of the production of antifungal bioactive metabolites, inhibitory bacteria were cultured on different culture conditions, including media, pH, temperature, and incubation time. RESULTS: In total, 110 bacterial strains were isolated from the forest soils and four species with high antifungal activity were identified as Streptomyces libani, Streptomyces angustmyceticus, Bacillus subtilis, and Sphingopyxis spp. on the basis of 16s ribosomal RNA sequencing. Dichloromethane extract of the starch casein broth culture filtrate of the S. libani (incubated at 30° C for five days) showed strong antifungal activity against A. fumigatus, Aspergillus niger, and Aspergillus flavus. CONCLUSION: Based on the results, forest soils contain organisms with antifungal activity and could be considered as a good source for novel antifungal metabolites as effective and safe therapeutics.

Candiduria in children and susceptibility patterns of recovered Candida species to antifungal drugs in Ahvaz.

BACKGROUND: Candiduria presents as an increasingly common nosocomial infection, which may involves urinary tract. Spectrum of disease is varying from asymptomatic candiduria to clinical sepsis. Disease is most commonly caused by Candida albicans. OBJECTIVES: The aim of the present study was to determine the frequency of candiduria in children attending Abuzar Pediatrics Hospital. PATIENTS AND METHODS: Urine samples were collected from 402 patients attending to the Abuzar Pediatrics Hospital, Ahvaz. 10µl of each urine sample was cultured on CHROMagar Candida plates and incubated at 37°C. Ketoconazole, amphotericine B, clotrimazole, fluconazole, miconazole and nystatin disks were used for determination of susceptibility. RESULTS: In the present study, 402 patients with the age range <1-14 years were sampled (59.2% males and 40.8% females). Prevalence of Candida among enrolled patients was found to be 5.2% (71.4% males and 28.6% females). In our study C. albicans was identified in 19 cases as the most common yeast followed by nine C. glabrata and one C. krusei. Urine cultures were yielded more than 10000 CFU/ml in 14.3% of the cases followed by 600-10000 CFU/ml (28.5%) and 100-600 CFU/ml (57.2%). Antifungal susceptibility testing revealed that only one isolate of C. glabrata and seven isolates of C. albicans were resistant to nystatin and ketoconazole, respectively.  However, all tested isolates were resistance to fluconazole. CONCLUSION: Asymptomatic candiduria is relatively more prevalent among children in Ahvaz and the most common agent is C. albicans. In addition, isolated Candida species were sensitive to use antifungals, with exception to fluconazole.