Comparative analysis of galactomannan lateral flow assay, galactomannan enzyme immunoassay and BAL culture for diagnosis of COVID-19-associated pulmonary aspergillosis.

BACKGROUND: Galactomannan Enzyme Immunoassay (GM-EIA) is proved to be a cornerstone in the diagnosis of COVID-19-associated pulmonary aspergillosis (CAPA), its use is limited in middle and low-income countries, where the application of simple and rapid test, including Galactomannan Lateral Flow Assay (GM-LFA), is highly appreciated. Despite such merits, limited studies directly compared GM-LFA with GM-EIA. Herein we compared the diagnostic features of GM-LFA, GM-EIA and bronchoalveolar lavage (BAL) culture for CAPA diagnosis in Iran, a developing country. MATERIALS/METHODS: Diagnostic performances of GM-LFA and GM-EIA in BAL (GM indexes ≥1) and serum (GM indexes >0.5), i.e. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) and areas under the curve (AUC), were evaluated using BAL (n = 105) and serum (n = 101) samples from mechanically ventilated COVID-19 patients in intensive care units. Patients were classified based on the presence of host factors, radiological findings and mycological evidences according to 2020 ECMM/ISHAM consensus criteria for CAPA diagnosis. RESULTS: The Aspergillus GM-LFA for serum and BAL samples showed a sensitivity of 56.3% and 60.6%, specificity of 94.2% and 88.9%, PPV of 81.8% and 71.4%, NPV of 82.3% and 83.1%, when compared with BAL culture, respectively. GM-EIA showed sensitivities of 46.9% and 54.5%, specificities of 100% and 91.7%, PPVs of 100% and 75%, NPVs of 80.2% and 81.5% for serum and BAL samples, respectively. CONCLUSION: Our study found GM-LFA as a reliable simple and rapid diagnostic tool, which could circumvent the shortcomings of culture and GM-EIA and be pivotal in timely initiation of antifungal treatment.

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.

Diagnosis of allergic bronchopulmonary aspergillosis in patients with persistent allergic asthma using three different diagnostic algorithms.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) has been reported in various degrees among patients with persistent allergic asthma (PAA). Currently, there is no gold standard approach for diagnosis of ABPA. OBJECTIVES: In the current study, we aimed the evaluation of three different mainly used algorithms as Rosenberg & Patterson (A), ISHAM Working Group (B) and Greenberger (C) for diagnosis of ABPA in 200 patients with underlying PAA. METHODS: All patients were evaluated using Aspergillus skin prick test (SPTAf), Aspergillus-specific IgE (sIgEAf) and IgG (sIgGAf), total IgE (tIgE), pulmonary function tests, radiological findings and peripheral blood eosinophil count. The prevalence rate of ABPA in PAA patients was estimated by three diagnostic criteria. We used Latent Class Analysis for the evaluation of different diagnostic parameters in different applied ABPA diagnostic algorithms. RESULTS: Aspergillus sensitisation was observed in 30 (15.0%) patients. According to algorithms A, B and C, nine (4.5%), six (3.0%) and 11 (5.5%) of patients were diagnosed with ABPA, respectively. The sensitivity and specificity of criteria B and C were (55.6% and 99.5%) and (100.0% and 98.9%) respectively. sIgEAf and sIgGAf showed the high significant sensitivity. The performance of algorithm A, in terms of sensitivity and specificity, was somewhat better than algorithm B. CONCLUSION: Our study demonstrated that the sensitivity of different diagnostic algorithms could change the prevalence rate of ABPA. We also found that all of three criteria resulted an adequate specificity for ABPA diagnosis. A consensus patterns combining elements of all three criteria may warrant a better diagnostic algorithm.

Familial Cases of Trichophyton benhamiae Infection Transmitted from a Guinea Pig in Iran.

Trichophyton benhamiae is a zoophilic dermatophyte mainly transmitted to humans from guinea pigs. This zoophilic species can also cause dermatophytosis as reported by human contact with other animals, such as rabbit, cat, and fox. Here, we report the tinea faciei and tinea corporis cases: a 12-year-old girl and her 53-year-old father, with no history of immunodeficiency and underlying disease, caused by T. benhamiae transmitted from a guinea pig in Iran. Dermatological examination revealed several erythematous, round, scaly, and approximately 1-4-cm-diameter lesions in both patients. The girl had seven skin lesions, and her father presented two skin lesions on the front side of his neck. The girl's lesions had started 3 weeks before and her father's lesions appeared 7 days after the first clinical appearance of the lesions in the daughter. The girl had daily close contact with a guinea pig, while her father did not have any direct exposure to the pet. Examination of the lesions scraping with 10% potassium hydroxide (KOH 10%) revealed hyaline septate hyphae and arthroconidia. The dermatophyte isolated in culture was identified as T. benhamiae using molecular analysis. The patients were successfully treated using topical sertaconazole nitrate 2% cream twice a day for 4 weeks.

Genotyping and In Vitro Antifungal Susceptibility Profile of Neoscytalidium Species Isolates from Respiratory Tract.

The fungus genus Neoscytalidium is mainly distributed in (sub) tropical regions of the world and has been essentially considered as a phytopathogen. There are however several reports of human infection caused by Neoscytalidium spp. through direct or indirect contact with contaminated plants or soil. Reliable and accurate identification to species level is critical for implementing proper therapeutic strategies. In the present study we investigated the genotypes and in vitro antifungal susceptibility patterns of Neoscytalidium species identified from respiratory tracts of patients with various underlying diseases. The identity and diversity of the isolates were done using PCR and sequencing of five different loci (the ITS region, D1/D2 domains of 28S rRNA gene, and part of the beta tubulin, elongation factor 1α and chitin synthase genes). The in-vitro antifungal susceptibility was also performed using the Clinical and Laboratory Standards Institute (CLSI) M38-Ed3-2017 guidelines. Overall, 13 isolates were identified as Neoscytalidium species (eight N. dimidiatum and five N. novaehollandiae). Two sequence types (STs) were identified by the alignment of 1846 combined base pairs among 13 clinical isolates. All isolates classified as N. dimidiatum were clustered in ST6 (61.5%) and those of N. novaehollandiae were in ST7 (38.5%). Luliconazole was the most active antifungal in vitro against species. This is the first report of N. novaehollandiae isolation from respiratory tracts samples. Further study from other regions of the world with a larger set of clinical specimens is required to provide additional insight into diversity of Neoscytalidium species.

Molecular epidemiology of Tinea gladiatorum in contact sports in northern Iran.

BACKGROUND: Tinea gladiatorum as the major health concern among combat athletes and the most common cause of a decrease in the quality of their sports activities. OBJECTIVES: This study aimed to determine the molecular epidemiology of tinea gladiatorum in contact sports in Mazandaran Province, Northern Iran. MATERIALS/METHODS: In total, 631 suspected athletes out of 4240 ones were screened for tinea gladiatorum in this cross-sectional study from May 2018 to February 2019. The infection was confirmed by direct microscopy and culture tests. The causative agents were identified by polymerase chain reaction-restriction fragment length polymorphism method on ITS rDNA region. The indoor environmental factors were evaluated in 81 sports halls in terms of temperature (°C), humidity (%), density (m2 /athletes) and the number of ventilators. RESULTS: Tinea gladiatorum was confirmed in 6.5% (278/4240) of the athletes. Tinea corporis was the most common type of tinea (192/278; 69.0%), and 175 cases (27.7%) had more than one type of tinea. Moreover, Trichophyton tonsurans (192/203; 94.5%) was the most aetiological agent in all athletes followed by Microsporum canis (6/203; 2.9%), Trichophyton rubrum (2/203; 0.9%) and Trichophyton interdigitale (1/203; 0.4%). There was no significant association between the prevalence of tinea gladiatorum and the indoor environmental factors. CONCLUSION: T. tonsurans is the most common agent of tinea gladiatorum in Northern Iran. Since no positive culture of dermatophyte was obtained from mats, it seems that skin-to-skin contact would be the most probable mode of transmission among wrestlers. Accordingly, periodical checkups should be considered by health care providers.

In vitro activities of antifungal drugs against a large collection of Trichophyton tonsurans isolated from wrestlers.

BACKGROUND: Trichophyton tonsurans is the most common agent causing tinea gladiatorum in wrestlers, and limited data on susceptibility profiles of Trichophyton tonsurans are available. OBJECTIVES: We aimed to assess the in vitro activity of the common antifungal drug against a large collection of T tonsurans. MATERIALS/METHODS: The in vitro activities to eight common antifungal drugs (sertaconazole, itraconazole, clotrimazole, fluconazole, butenafine, tolnaftate, terbinafine and griseofulvin) against 128 clinical isolates of T tonsurans strains, obtained from wrestlers with dermatophytosis, were performed according to CLSI M38-A2 broth microdilution document. RESULTS: The geometric mean minimum inhibitory concentration was the lowest for tolnaftate (0.022 µg/mL), followed by itraconazole (0.026 µg/mL), terbinafine (0.033 µg/mL), butenafine (0.088 µg/mL), griseofulvin (0.566 µg/mL), sertaconazole (2.875 µg/mL), clotrimazole (3.419 µg/mL) and fluconazole (12.540 µg/mL). CONCLUSIONS: Evaluation of antifungal susceptibility of dermatophytes showed that tolnaftate and itraconazole were the most effective drugs against T tonsurans and fluconazole had the least effect.

Galactomannan detection in bronchoalveolar lavage fluids: A diagnostic approach for fungus ball in patients with pulmonary tuberculosis?

BACKGROUND: Several previous studies have shown cavitary lung lesions in old pulmonary tuberculosis (PTB) increase the risk of fungus ball. Detection of galactomannan (GM) in bronchoalveolar lavage (BAL) is also proposed as a diagnostic approach for the fungus ball. OBJECTIVES: We evaluated the diagnosis of fungus balls and GM levels in BAL samples in PTB patients. METHODS: A total of 110 PTB patients were evaluated for fungus ball during 2017-2019. The patients were evaluated for radiological, histopathological results and mycological findings of BAL including GM detection and culture. The sensitivity, specificity and positive and negative predictive value for GM test were calculated. The optimal cut-off for BAL GM testing was determined by receiver operating characteristic (ROC). RESULTS: Of 110 PTB patients, nine (8.18%) showed fungus ball, all with old PTB. The molecularly confirmed Aspergillus species were A. flavus, A. fumigatus and A. ochraceus. The sensitivity and specificity of BAL GM ≥ 0.5 in old PTB patients with fungus ball were 100%, 41.5%, respectively. The statistical analysis of the mean ± SEM of BAL GM levels was demonstrated a higher levels of GM in patients with fungus ball/aspergilloma compared to old PTB patients without fungus ball/aspergilloma. The optimal cut-off value for BAL GM was determined as 0.50 by ROC curve analysis. CONCLUSION: According to our results, we can recommend the detection of GM in BAL samples as a diagnostic approach for fungus ball in PTB patients.

Genetic diversity and antifungal susceptibility patterns of Aspergillus nidulans complex obtained from clinical and environmental sources.

The molecular epidemiology and antifungal susceptibility of Aspergillus nidulans species complex has not been well studied. To evaluate the genetic diversity and antifungal susceptibility patterns of clinical and environmental isolates of A. nidulans complex. Sixty clinical and environmental isolates of Aspergillus section Nidulantes were collected from five countries (Iran, The Netherlands, Spain, Portugal and Greece). The species were molecularly identified by sequencing of ß-tubulin gene. The genetic diversity of A nidulans complex isolates (n = 54) was determined with a microsatellite genotyping assay. Antifungal susceptibility profile was determined using EUCAST method. The isolates were classified as A nidulans (46.7%), A spinulosporus (26.6%), A quadrilineatus (10%), A pachycristatus (3.3%), A rugulosus (3.3%), A unguis (5%), A creber, (1.7%), A olivicola (1.7%) and A sydowii (1.7%). Thirty-four sequence types (STs) were identified among the 54 A nidulans complex isolates. A high level of genetic diversity was found among A nidulans sensu stricto strains but low diversity was found among A spinulosporus strains. Amphotericin B showed high MICs to all species. The most active azole was posaconazole (GM = 0.64 mg/L), while itraconazole showed the highest MICs among azoles (GM = 2.95 mg/L). A spinulosporus showed higher MICs than A nidulans sensu stricto for all antifungals except for micafungin and anidulafungin. Interspecies variations may result in differences in antifungal susceptibility patterns and challenge antifungal therapy in infections caused by A nidulans. Differences in the distribution of STs or persistence of multiple STs might be related to the sources of isolation and niche specialisation.

Fungal epidemiology in cystic fibrosis patients with a special focus on Scedosporium species complex.

In this present study, for the first time, we evaluated the cystic fibrosis (CF) patients for the Scedosporium species and their antifungal susceptibility against eight antifungal agents. During one-year period, 90 Sputum samples were collected from Iranian CF patients. All samples were evaluated by direct microscopic examination, culture onto four different media including Malt extract agar, Inhibitory mold agar, Brain Heart Infusion and Scedo-Select III. The mold isolated fungi were identified by PCR-Sequencing of ITS and ß-tubulin genes. In-vitro antifungal susceptibility was performed according to the Clinical & Laboratory Standards Institute (CLSI) M38-A2 guidelines. Out of 90 CF patients, 47 (52.2%) were male. The age of the patients ranged from 1 to 34 years (median of 15.84 ±â€¯7.41 years). Overall, 3 (3.3%) cases were positive for Scedosporium spp. of which two isolates were characterized as Scedosporium boydii and one isolate as S. ellipsoideum. Among Aspergillus genus, A. flavus (29.4%) was the most prevalent species followed by A. tubingensis (24.7%), A. niger (17.0%) and A. fumigatus (14.5%). The minimum effective concentration ranges of micafungin, anidulafungin, and caspofungin were 0.008-0.031 µg/mL, 0.0625-0.25 µg/mL, and 0.0625-0.25 µg/mL, respectively. All isolates of Scedosporium species showed high minimum inhibitory concentration to the triazoles tested, except voriconazole. Our results showed that A. flavus and Scedosporium species are the most prevalent molds isolated from CF patient populations in Iran. Our findings have also showed that Scedo-Select III can be used as a reliable culture media for isolation of Scedosporium spp. in clinical samples.

In-vitro antifungal susceptibility testing of lanoconazole and luliconazole against Aspergillus flavus as an important agent of invasive aspergillosis.

INTRODUCTION: The incidence of Aspergillus infections has recently increased remarkably in certain tropical and sub-tropical countries, with Aspergillus flavus being identified as the leading cause of infections after A. fumigatus. Lanoconazole (LAN) and luliconazole (LUL) are currently approved for topical treatment of cutaneous fungal infections. We aimed the in-vitro antifungal susceptibility testing of two imidazole, LAN and LUL against A. flavus. METHODS: One hundred and eighty-seven clinical and environmental A. flavus were tested originating from different climate zones of Iran between 2008 and 2015. The identification of all isolates was confirmed by using PCR-sequencing of ß-tubuline ribosomal DNA gene. In-vitro antifungal susceptibility test was performed using CLSI guidelines against LAN, LUL, itraconazole (ITC), voriconazole (VRC), posaconazole (POS), Isavuconazole (ISA), amphotericin B (AMB), 5-flucytosine (5FC), caspofungin (CAS) and anidulafungin (AFG). The minimum inhibitory concentration (MIC) and minimum effect concentration (MEC) values were evaluated according to CLSI M38-A2 guidelines. RESULTS: The geometric mean MICs for tested antifungals, in increasing order, were: 0.009 µg/mL for LUL (ranging from 0.004 to 0.062), 0.02 µg/mL for LAN (ranging from 0.004 to 0.125), POS (0.10), ISA (0.16), ITC (0.24), VRC (0.27), AMB (1.8) and 5FC (63.06) µg/mL. The mean value of MECs for AFG and CAS were 0.06 and 0.07, respectively. CONCLUSION: Overall, LUL and LAN showed the lowest MIC against all isolates of A. flavus. Further studies are required to evaluate the in-vivo efficacy of these agents, and the possibility of using these agents in systemic infections.

Discrimination of Aspergillus flavus from Aspergillus oryzae by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry.

BACKGROUND: Aspergillus flavus is a major cause of severe non-invasive fungal infections in the Middle Eastern countries. However, it is difficult to distinguish A flavus from A oryzae. OBJECTIVES: To assess the potential of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in discriminating between A flavus and A oryzae and compare it with ß-tubulin gene sequencing. METHODS: We used the Bruker Daltonik MALDI-TOF MS system to analyse 200 clinical and environmental A flavus isolates and one A pseudonomius and one A alliaceus (Aspergillus section Flavi) isolate a priori identified as such by sequencing of the ß-tubulin gene. RESULTS: All 200 A flavus isolates were identified at the genus level and 176 (88%) at the species levels by MALDI-TOF MS based on the spectral log-scores (≥2.0 and 1.7-1.99, respectively); among them, only 18 (10.2%) were confirmed as A flavus, whereas 35 (19.9%) were identified as A oryzae and 123 (69.9%) as A flavus/A oryzae. Aspergillus pseudonomius and A alliaceus were misidentified as A flavus and A parasiticus with log-score values of 1.39 and 1.09, respectively. CONCLUSIONS: The results indicate that the commercially available Bruker Daltonik MALDI-TOF MS score database cannot separate A flavus and A oryzae species. We also showed that establishment of an in-house library is a useful tool to discriminate closely related Aspergillus species, including A flavus and A oryzae.

In vitro antifungal activity of amphotericin B and 11 comparators against Aspergillus terreus species complex.

Aspergillus terreus infections are difficult to treat because of the intrinsic resistance to amphotericin B, and higher mortality compared to infections caused by other Aspergillus species. The aim of the present study was to determine the in vitro antifungal activity of amphotericin B and 11 comparators against clinical (n = 36) and environmental (n = 45) A. terreus isolates. In vitro antifungal susceptibility was performed using the CLSI M38-A2 procedure. Amphotericin B exhibited the highest MICs (MIC range, 0.125-4 µg/mL; MIC90 , 2 µg/mL), followed by terbinafine (MIC range, 0.002-1 µg/mL; MIC90 , 1 µg/mL). Only one isolate (1/81) showed amphotericin B MIC above the epidemiologic cut-off value (ECV; 4 µg/mL). None of the isolates had a MIC of ≥ ECV for voriconazole, itraconazole and posaconazole. The reasons for the difference in amphotericin B susceptibility patterns between studies remain unknown. The genetic and species diversity, clinical, environmental and ecological factors in Terrei section on various amphotericin B susceptibility profiles in different countries should be considered more as the main reasons associated with these differences.

In Vitro Antifungal Susceptibility Profiles of 12 Antifungal Drugs against 55 Trichophyton schoenleinii Isolates from Tinea Capitis Favosa Patients in Iran, Turkey, and China.

Trichophyton schoenleinii is an anthropophilic dermatophyte mainly causing tinea favosa of the scalp in certain regions of the world, especially Africa and Asia. We investigated the in vitro susceptibilities of 55 T. schoenleinii isolates collected over the last 30 years from Iran, Turkey, and China to 12 antifungals using the CLSI broth microdilution method. Our results revealed that terbinafine and ketoconazole were the most potent antifungal agents among those tested, independently of the geographic regions where strains were isolated.

Discrimination of Aspergillosis, Mucormycosis, Fusariosis, and Scedosporiosis in Formalin-Fixed Paraffin-Embedded Tissue Specimens by Use of Multiple Real-Time Quantitative PCR Assays.

In a retrospective multicenter study, 102 formalin-fixed paraffin-embedded (FFPE) tissue specimens with histopathology results were tested. Two 4- to 5-µm FFPE tissue sections from each specimen were digested with proteinase K, followed by automated nucleic acid extraction. Multiple real-time quantitative PCR (qPCR) assays targeting the internal transcribed spacer 2 (ITS2) region of ribosomal DNA, using fluorescently labeled primers, was performed to identify clinically important genera and species of Aspergillus, Fusarium, Scedosporium, and the Mucormycetes The molecular identification was correlated with results from histological examination. One of the main findings of our study was the high sensitivity of the automated DNA extraction method, which was estimated to be 94%. The qPCR procedure that was evaluated identified a range of fungal genera/species, including Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger, Fusarium oxysporum, Fusarium solani, Scedosporium apiospermum, Rhizopus oryzae, Rhizopus microsporus, Mucor spp., and Syncephalastrum Fusarium oxysporum and F. solani DNA was amplified from five specimens from patients initially diagnosed by histopathology as having aspergillosis. Aspergillus flavus, S. apiospermum, and Syncephalastrum were detected from histopathological mucormycosis samples. In addition, examination of four samples from patients suspected of having concomitant aspergillosis and mucormycosis infections resulted in the identification of two A. flavus isolates, one Mucor isolate, and only one sample having both R. oryzae and A. flavus Our results indicate that histopathological features of molds may be easily confused in tissue sections. The qPCR assay used in this study is a reliable tool for the rapid and accurate identification of fungal pathogens to the genus and species levels directly from FFPE tissues.

Molecular Characterization and In Vitro Antifungal Susceptibility of 316 Clinical Isolates of Dermatophytes in Iran.

Dermatophytosis is a common mycotic infection of the skin, nail, and hair, associated with major public health concern worldwide. Various species of dermatophytes show significant differences in susceptibility to antifungals. Here, we present the antifungal susceptibility of a large collection of molecularly identified dermatophyte isolates obtained from tropical region of south of Iran. A total of 9485 patients clinically suspected to have cutaneous fungal infections were examined. Dermatophytosis was confirmed in 1502 cases by direct microscopy and culture. Three hundred and sixteen isolates recovered in culture were identified to species level using PCR sequencing of ITS region and RFLP. Tinea corporis was the most prevalent type of clinical manifestation (35.2 %), followed by tinea cruris (17 %), tinea capitis (12.8 %), tinea pedis (11.3 %), tinea manuum (11 %), tinea unguium (6.9 %), and tinea barbae (5.8 %). Trichophyton interdigitale was the most common isolate (49.36 %), followed by Trichophyton rubrum (18.98 %), Epidermophyton floccosum (13.29 %), Microsporum canis (9.17 %), Arthroderma benhamiae (T. anamorph of A. benhamiae; 5.38 %), and Trichophyton tonsurans (3.79 %). Overall, irrespective of the geographical region, terbinafine was the most potent antifungal against all isolates, with an MIC range of 0.002-0.25 µg/mL, followed by itraconazole (0.004-0.5 µg/mL), griseofulvin (0.125-8 µg/mL), and fluconazole (4-128 µg/mL). Analysis of our data revealed a significant increase in the frequency of A.benhamiae, which definitely warrants further investigation to explore source of this infection in south of Iran. Moreover, terbinafine was the most effective antifungal against all isolates, in vitro.

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

The 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.

cyp51A gene silencing using RNA interference in azole-resistant Aspergillus fumigatus.

An increasing number of reports have described the emergence of acquired resistance of Aspergillus fumigatus to azole compounds. The primary mechanism of resistance in clinical isolates is the mutation of the azole drug target enzyme, which is encoded by the cyp51A gene. The aim of this study was to evaluate the impact of silencing the cyp51A gene in azole-resistant A. fumigatus isolates. A 21-nucleotide small-interfering RNA (siRNA) was designed based on the cDNA sequence of the A. fumigatus cyp51A gene. After silencing the cyp51A gene in germinated conidia (15, 20, 25 and 50 nM), azole-resistant A. fumigatus was cultured on broth media and gene expression was analysed by measuring the cyp51A mRNA level using RT-PCR assay. Hyphae were successfully transfected by siRNA and expression of the cyp51A gene was significantly reduced by siRNA at the concentration of 50 nM (P ≤ 0.05). In addition, at this siRNA concentration, the minimum inhibitory concentration of itraconazole for the treated cells was decreased, compared with that for untreated control cells, from 16 to 4 µg/ml.

Tinea capitis due to Microsporum ferrugineum: A case of unusual laboratory finding on direct microscopic examination of infected hairs and skin lesions.

Tinea capitis is a chronic fungal infection of the scalp occurring commonly in children of school age, especially in developing countries. It is caused primarily by the dermatophyte members of genera Microsporum and Trichophyton. Here we report presence of free-living mycelial stage of dermatophytes, a stage of fungal growth which form in culture medias, around affected hairs and skin scrapings of scalp lesions in a 3-year-old boy presenting with alopecia and multiple scaly, non-erythematous plaques. On direct microscopy examination using 10 % potassium hydroxide, the fungal hyphae and arthrospores were detected in ectothrix form. In addition, we also observed numerous multicellular, thick-walled spindle-shaped macroconidia around hairs and skin scrapings. To our knowledge this is the first study reporting dermatophyte's macroconidia directly seen on clinical samples. Species level identification of the dermatophyte isolate growing on Mycosel™ agar was confirmed by PCR-sequencing of internal transcribed spacer of ribosomal RNA as Microsporum ferrugineum. The patient was successfully treated with systemic itraconazole combined with topical ketoconazole shampoo.

Environmental study of azole-resistant Aspergillus fumigatus with TR34/L98H mutations in the cyp51A gene in Iran.

Azole resistance in Aspergillus is emerging in European and Asian countries. As azoles are mainstay of therapy in the management of aspergillosis, azole resistance has serious implications in patient management. We report the emergence of resistance to triazoles in environmental Aspergillus fumigatus isolates in Iran. The TR34/L98H mutation was the only resistance mechanism. Overall 3.3% of the A. fumigatus isolates from hospital surroundings in Sari and Tehran had the same TR34/L98H STRAf genotype and were related to some resistant clinical and environmental TR34/L98H isolates from the Netherlands and India. It is emphasised that routine resistance surveillance studies focusing on environmental and clinical samples are warranted to yield the true prevalence of azole resistance in A. fumigatus in Iran.