Increasing incidence of Trichophyton tonsurans in Munich-A single-centre observation.

BACKGROUND: Tinea capitis and tinea corporis are highly prevalent fungal skin infections, which globally are mainly caused by Microsporum canis and Trichophyton rubrum, respectively. While in the United States and Great Britain Trichophyton tonsurans is widely prevalent as a causative pathogen, it so far only plays a minor role in Germany. OBJECTIVES: Since the frequency of pathogenic species varies regionally and temporally, this study assesses the proportion of Trichophyton tonsurans infections in the dermatology department of a large university hospital in Germany from 2019 to 2022 and thoroughly characterises the affected patient population. PATIENTS/METHODS: This retrospective study at the Technical University of Munich analyses mycological culture results regarding the identified dermatophyte and infection site. Detailed patient and disease-related information on Trichophyton tonsurans positive patients was obtained. RESULTS: In 2022, 23 patients of 111 dermatophyte culture-positive patients tested positive for Trichophyton tonsurans. This accounted for 20.7% and represented a tenfold increase from 2.1% in 2019. Contact sports were only practiced by 21.7% of patients, and no common hotspot or other linkage could be identified between the cases. Additionally, 47.8% of the patients received a systemic treatment, with 30.4% visiting the clinic more than three times. In 2022, 21.7% were diagnosed with a simultaneous infection of the capillitium and body, whereas this was only observed in 7.1% of cases in 2019 to 2021. CONCLUSIONS: This study suggests an increase of Trichophyton tonsurans infections via several routes of transmission.

VHL-dependence of EHHADH Expression in a Human Renal Cell Carcinoma Cell Line.

The von Hippel-Lindau tumor suppressor gene (VHL) is mutated in up to 90% of clear cell renal cell carcinoma (ccRCC) cases, thus playing a key role in ccRCC pathogenesis. ccRCC can be classified as a metabolic disease in which alterations in fatty acid metabolism facilitate cancer cell proliferation. Enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH) is an enzyme involved in peroxisomal fatty acid degradation. It is primarily expressed in renal proximal tubule cells, presumably the origin of ccRCC. Although EHHADH is still a relatively unexplored gene, it is known to be differentially expressed in several tumors. In this study, analysis of several databases revealed that EHHADH expression is downregulated in ccRCC samples compared to healthy kidney samples. Moreover, cell culture experiments were performed to investigate the relationship between EHHADH and VHL at the gene and protein level. qPCR and Western blot analyses using the human ccRCC cell line RCC4 revealed that EHHADH is expressed in a VHL-dependent manner. RCC4 cells reconstituted with VHL show significantly higher EHHADH mRNA and protein levels than VHL-deficient RCC4 control cells. These results indicate that the downregulation of EHHADH in ccRCC reported may be due to the loss of VHL function. This study is the first to molecularly characterize EHHADH, a key enzyme in peroxisomal ß-oxidation, in relation to VHL, suggesting a potential pathogenic interaction that is worthy of further investigation.