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Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM Objective The epidemic of antifungal-resistant dermatophytosis in India has been reported. These infections are associated with severe morbidity, resistance to oral itraconazole and terbinafine, and the widespread misuse of topical steroids. Trichophyton indotineae has emerged as the predominant causative agent. In this study, we investigated 162 dermatophytosis infections from eight Indian states using genomic sequencing. The primary objective was to determine whether a clonal outbreak strain is responsible for the current epidemic. Methods A total of 161 T. indotineae and one T. rubrum isolates from skin scrapings collected from India in 2017-2019 and previously reported were sent to the U.S. Centers for Disease Control and Prevention (CDC) for genomic analysis. After species identification, genomic DNA was extracted and sequenced using Illumina NovaSeq. Single-nucleotide (SNP) analysis was performed using the portable workflow MycoSNP (v0.21). Briefly, MycoSNP prepared the reference genome, performed pre-processing, aligned sample reads to the reference using the BWA (v 0.7.17) alignment algorithm, and called variants using GATK (v4.1.4.1). High-quality SNPs were used for constructing phylogenetic trees using neighbor-joining (NJ) and maximum likelihood (ML) methods. Further, to understand if infections are genetically clustered by state or region, multi-dimensional scaling (MDS) was applied using the ML tree in R. Result SNP analysis identified 1259 450 variant sites which were used to construct an NJ and ML tree. The tree topology from both NJ and ML methods showed consensus. All 161 T. indotineae isolates from India clustered together forming a large, well-supported clade. SNP differences between the samples varied from 0-160 SNPs. Historical isolates available at CDC were included as controls and clustered over 40 000 SNPs from the clade comprising isolates from India. The MDS plot revealed that isolates did not cluster by state or region. Conclusion Antifungal-resistant dermatophytosis is an emerging threat with cases of chronic, recurrent infection reported from several countries including India. Additionally, the rapid spread of infections involves person-to-person spread. Our results suggest that a clonal outbreak of a T. indotineae strain is circulating in multiple states in India. Current plans are to expand the geographic scope of the study by including over 10 countries from Europe, Middle East, and the Americas. This work will allow the public health community to better understand the emergence and transmission of antifungal-resistant dermatophytosis worldwide.

Summary Background The prevalence of onychomycosis has increased steadily in the past decade. An accurate diagnosis at the outset is important for successful and cost-effective treatment of patients. However, current diagnostic tests for onychomycosis are not rapid, sensitive or specific. Objectives To develop a microsatellite-based polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (MS-ELISA) for the detection of Trichophyton rubrum, which is the most common aetiological agent of onychomycosis. Methods An archival set of 434 nail and skin specimens from 217 patients was included as the test sample in this study. We also compared MS-ELISA with an earlier published topoisomerase PCR-ELISA (TI-ELISA) using template DNA extracted by another method. Results The MS-ELISA detected the highest number of positive samples (69%) followed by direct microscopy (56%), TI-ELISA (44%) and fungal culture (30%). When an identical DNA extraction method was applied to 120 specimens, the MS-ELISA proved to be twice as sensitive as the TI-ELISA. Conclusions We have optimized a target gene and DNA extraction method for rapid detection of T. rubrum onychomycosis.

Altogether 285 dermatophyte isolates of 21 different species - including both Trichophyton rubrum and T. interdigitale, but also eight additional Trichophyton species, Microsporum canis and seven other Microsporum species, as well as Epidermophyton floccosum and Arthroderma spp. - were analyzed using Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and the AnagnosTec 'SARAMIS' (Spectral Archiving and Microbial Identification System) software. In addition, sequence analysis of the internal transcribed spacer (ITS) of the ribosomal DNA was performed for a high number of the tested strains. Sufficient agreement was found between the results obtained with standard identification methods and those with the MALDI-TOF MS for species identification of dermatophytes. A mass spectra database was constructed which contained the species identifications of all 285 isolates. The results were confirmed for 164 of the isolates by sequence analysis of the internal transcribed spacer (ITS) of the ribosomal DNA. Statistical analysis of all 285 dermatophyte strains showed that conventional identification matched the results of MALDI-TOF MS for 78.2% of the isolates tested. In the case of the 164 isolates for which the identifications were confirmed by PCR, the results of their conventional diagnosis and MALDI-TOF MS were in agreement for only 68.9 % (113 of 164 strains) of the test isolates. In contrast, there was agreement of 99.3 % or 98.8 % in the identifications obtained with PCR and MALDI-TOF MS techniques (283/285 or 162/164). The two exceptions were isolates that proved to be T. violaceum which could not be identified by the MALDI-TOF MS technique. In conclusion, the MALDI-TOF mass spectroscopy represents a fast and very specific method for species differentiation of dermatophytes grown in culture.

The basidiomycete Coprinus sp. was isolated repeatedly from bronchial secretions and bronchoalveolar lavage of a 40-year-old woman suffering from a relapse of acute lymphoblastic leukemia 5 years after she underwent autologous bone marrow transplantation. Post-mortem microbiological investigation of lung tissue revealed simultaneously growing Coprinus sp. and Aspergillus flavus. Histopathological examination of the lung demonstrated septate hyphae characteristic of both Aspergillus and Coprinus. The basidiomycete Coprinus sp. should be considered as a potential opportunistic pathogen because of its excellent growth at 37°C.