Molecular epidemiology and in vitro antifungal susceptibility of Trichophyton schoenleinii, agent of tinea capitis favosa

In vitro virulotyping, antifungal susceptibility testing and DNA fingerprinting of Microsporum canis strains of canine and feline origin

Microsporum canis is considered the common dermatophyte agent associated with ringworm in felines and canines. In the present study, we sampled n = 548 felines and canines for the probable isolation of M. canis. The rate of isolation from the cats and dogs was 70.27 % (52/74) and 1.68 % (8/474), respectively and Persian cats were found to be highly susceptible to M. canis infection. The strains were evaluated for their production of phospholipase, lipase, catalase, and hemolysis and their ability to grow at 35 ℃. All the strains were identified as low producers of catalase and n = 17 strains exhibited high thermotolerance ability. Terbinafine was found to be the most effective antifungal drug and fluconazole was the least effective, in vitro. AFLP analysis revealed three genotypes of M. canis with 15 sub-clusters showing ≥ 90 % similarity and 7 sub-clusters exhibiting 100 % similarity. However, the phenotypic characters cannot be attributed based on the AFLP profiles.

Comparative Genomics and Molecular Analysis of Epidermophyton floccosum

Epidermophyton floccosum is one of the most common agents of human superficial fungal infections, compared with genus Trichophyton and Microsporum, it possesses uniqueness in ecology traits and rarely causing hair infections. E. floccosum is so far the only representative species of genera Epidermophyton, and it is known as anthropophilic dermatophytes. To further reveal the genome sequences and clues of virulence factors, thus in this study, we sequenced the genome of E. floccosum (CGMCC (F) E1d), and performed comparative genomic analysis with other dermatophytes. It is revealed that E. floccosum owns the largest genome size and similar GC content compared with other dermatophytes. A total of 7565 genes are predicted. By comparing with the closest species N. gypseum, our study reveals that number and structure of adhesion factors, secreted proteases and LysM domain might contribute to the pathogenic and ecological traits of E. floccosum. Mating genes is also detected in genome data. Furthermore, we performed AFLP analysis trying to discuss intraspecific differences of E. floccosum, but no significant relationship is found between genotype and geographical distribution. Upon above, our study provides a deeper understanding and strong foundation for future researches about E. floccosum.

Comprehensive genome and transcriptome analysis of the dermatophyte Trichophyton schoenleinii reveals the candidate pathogenic genes

BACKGROUND

Trichophyton schoenleinii is an anthropophilic dermatophyte that causes tinea favosa. Nowadays, it remains an important pathogen in some regions of the world, mainly epidemic in Africa and West Asia. Despite the medical importance of T. schoenleinii infections, a high-quality reference genome for T. schoenleinii is still unavailable, neither its transcriptomic profile.

OBJECTIVES

The aim of the current study was to improve understanding of the underlying pathogenic mechanism of T. schoenleinii, and to define the candidate pathogenic genes of T. schoenleinii.

METHODS

Comprehensive genomic analysis of T. schoenleinii was carried out by Illumina and PacBio sequencing platforms. Transcriptome profiles of T. schoenleinii cultured in vitro in two media containing either keratin or soy protein were determined using RNA sequencing (RNA-seq) technology.

RESULTS

Here, we present the first draft genome sequence of T. schoenleinii strain T2s, which consists of 11 scaffolds containing 7474 predicted genes. Transcriptome analysis showed that genes involved in keratin hydrolysis have higher expression in T. schoenleinii grown in keratin medium, including genes encoding proteases, cysteine dioxygenase and acetamidase. Other genes with higher expression include genes encoding the components of the pH-responsive signal transduction pathways and transcription factors, many of which may play a role in pathogenicity.

CONCLUSION

In summary, this study provides new insights into the pathogenic mechanism of T. schoenleinii and highlights candidate genes for further development of novel targets in disease diagnosis and treatment of tinea favosa.