Introduction: Trichophyton mentagrophytes and T. interdigitale are important causative agents of superficial mycoses, demonstrating emergent antifungal drug resistance. We studied the antifungal susceptibility profiles in Iranian isolates of these two species. Methods: A total of 96 T. interdigitale and 45 T. mentagrophytes isolates were subjected to molecular typing by ribosomal ITS region. Antifungal susceptibility profiles for terbinafine, griseofulvin, clotrimazole, efinaconazole, luliconazole, amorolfine and ciclopirox were obtained by CLSI broth microdilution method. The squalene epoxidase (SQLE) gene was subjected to sequencing for mutations, if any, in isolates exhibiting elevated MICs for terbinafine. Results: Luliconazole and efinaconazole showed the lowest MIC values against T. mentagrophytes and T. interdigitale isolates. There were five isolates with terbinafine MICs ≥32 µg/mL in our sample. They belonged to T. mentagrophytes type VIII and harbored two alternative SQLE gene sequence variants, leading to Phe397Leu and Ala448Thr or Leu393Ser and Ala448Thr substitutions in the enzyme. All terbinafine resistant strains could be inhibited by luliconazole and efinaconazole. Conclusion: This study documented a step in the global spread of resistance mechanisms in T. mentagrophytes. However, treatment alternatives for resistant isolates were available.

Background: Species from the Trichophyton benhamiae complex are mostly zoophilic dermatophytes which cause inflammatory dermatophytosis in animals and humans worldwide.Objectives: This study was purposed to (a) to identify 169 reference and clinical dermatophyte strains from the T benhamiae complex species by molecular method and adhering to the newest taxonomy in the complex (b) to evaluate the in vitro antifungal susceptibility profile of these strains against eight common and new antifungal agents that may be used for the treatment of dermatophytosis.Methods: All isolates, mainly originated from Europe but also from Iran, Japan and USA, were subjected to ITS-rDNA sequencing. The in vitro antifungal susceptibility profiles of eight common and new antifungal drugs against the isolates were determined by CLSI M38-A2 protocol and according to microdilution method.Results: Based on the ITS-rDNA sequencing, T benhamiae was the dominant species (n = 102), followed by T europaeum (n = 29), T erinacei (n = 23), T japonicum (n = 10), Trichophyton sp (n = 4) and T eriotrephon (n = 1). MIC ranges across all isolates were as follows: luliconazole: 0.0002-0.002 µg/ml, terbinafine: 0.008-0.125 µg/ml, efinaconazole: 0.008-0.125 µg/ml, ciclopirox olamine: 0.03-0.5 µg/ml, itraconazole: 0.06-2 µg/ml, griseofulvin: 0.25-4 µg/ml, amorolfine hydrochloride: 0.125-4 µg/ml and tavaborole: 1-16 µg/ml.

In this study, we describe two novel agents of dermatophytosis and summarize the clinical manifestation of infections. These new pathogens were discovered thanks to long-term molecular epidemiological studies conducted in Czechia and Iran. Zoonotic origins of the human infections are highly probable, but the animal hosts of these pathogens are poorly known. Further research is needed to refine our knowledge about these new pathogens.

Summary Background Dermatophytes are a group of keratinophilic fungi of medical importance. Despite a relatively long history of molecular taxonomic studies, there is still a need for information on genetic polymorphism in wider variety of genomic loci. Objectives Our goal was to study partial DNA topoisomerase 2 gene (TOP2) polymorphism in dermatophytes. Methods We performed DNA sequencing of TOP2 in 26 dermatophyte species along with ribosomal internal transcribed spacer (ITS) sequencing. Results The number of polymorphic sites in TOP2 data set was similar to that one in ITS data set. Nannizzia species formed paraphyletic group in TOP2 tree. Trichophyton simii was paraphyletic in concatenated TOP2‐ITS tree, one of its two clades contained solely Iranian isolates. Conclusions Our results revealed several unresolved problems in the taxonomy of dermatophytes, including probable polyphyly of the genus Nannizzia and the species T simii.

No abstract

No abstract

Background Fungal rhinosinusitis (FRS) encompasses a various spectrum of diseases. Histopathology is the “reference method” for diagnosing FRS, but it cannot determine the genus and species. Moreover, in more than 50% of the histopathologically proven cases, the culture elicited no reliable results. This study was an attempt to evaluate the diagnostic efficiency of semi‐nested polymerase chain reaction (PCR) from formalin‐fixed paraffin‐embedded (FFPE) functional endoscopic sinus surgery (FESS) in FRS patients. Methods One hundred ten specimens were subjected to DNA extraction and histopathology examination. The amplification of the β‐globin gene by conventional PCR was used to confirm the quality of extracted DNA. The semi‐nested PCR was performed using ITS1, ITS2, and ITS4 primers during two steps. Sequencing the internal transcribed spacer region (ITS1‐5.8S‐ITS2) to identify causative agents was performed on PCR products. Results Sixty‐four out of 110 samples were positive by histopathology evidence, of which 56 samples (87.5%) were positive by PCR. Out of 46 negative samples by histopathological methods, five samples (10.9%) yielded positive results by PCR. Sensitivity, specificity, positive predictive value, and negative predictive value of the semi‐nested PCR method were reported 87.5%, 89.2%, 92.7%, and 85.2%, respectively. The kappa factor between PCR and histopathological methods was 0.76, indicating substantial agreements between these two tests. Conclusion Due to the acceptable sensitivity and specificity of the present method, it might be used to diagnose fungal sinusitis infections along with microscopic techniques. This method is recommended to confirm the diagnose of suspected fungal sinusitis with negative histopathology results.

Background Fungal rhinosinusitis (FRS) encompasses a various spectrum of disease, which vary in clinical presentation, histologic features, and biological significance. FRS is commonly classified in two categories, i.e., invasive and non-invasive infection. Histopathology is the “gold standard” diagnostic method, but it is not able to determine the genus and species. Almost more than 50% of the histopathologically proven cases, the culture elicited no reliable results. This study was an attempt to evaluate the diagnostic efficiency of semi-nested polymerase chain reaction (PCR) to confirmation of pathology reports obtained from formalin-fixed paraffin-embedded (FFPE) functional endoscopic sinus surgery (FESS) in FRS patients. Methods One hundred ten specimens were subjected to DNA extraction and histopathology examination. The amplification of β-globin gene by conventional PCR was used for confirming the quality of extracted DNA. The semi-nested PCR was performed using ITS 1 and ITS4 primers during two steps. In order to identification of causative agents, sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2) was performed on PCR products. Results Sixty-four out of 110 samples were positive by histopathology evidence, of which 56 samples (87.5%) were positive by PCR and 8 (12.5%) samples were negative. Out of 46 negative samples by histopathological methods, 41 samples (89.1%) were negative in PCR while 5 (10.9%) were positive. Sensitivity, specificity, positive predictive value, and negative predictive value of the semi-nested PCR method were reported 87.5%, 89.2%, 92.7%, and 85.2%, respectively. Aspergillus flavus, Rhizopus oryzae, Lichtheimia corymbifera and Candida albicans have identified as common fungal species. Conclusion Based on staining and direct examination that are time-consuming, applying molecular methods might be an appropriate choice for rapid diagnosis and support the consequences of histopathology examinations. We suggest that fresh biopsy specimens elicit more reliable results in comparison with FFPE samples. It is recommended that semi-nested PCR assays be performed in a single tube, which showed less prone to contamination when compared with assays that were carried out in two stages and in separate tubes. Trial registration: Not applicable.