[Exophiala on the Stored Apples: Evaluation with One Health Perspective]

The one health perspective is an integrative and holistic approach that recognizes the interconnection and interdependence of human, animal and plant health and aims to improve each sustainably. This perspective has gained particular importance following the coronavirus disease-2019 pandemic and has been acknowledged as a component of public health. Fungal infections also pose significant risks to ecosystems, ranging from crops to animals and humans. These risks partly arise from human and animal mobility and have increased alongside climate change. Therefore, food safety has become an integral part of developing societies. Apples are the most widely consumed fruit worldwide. They are known to have multiple health benefits and have been reported to reduce the risk of chronic diseases such as cancer, diabetes, heart disease and stroke. Previous studies have shown that important human pathogens, including multidrug-resistant Candidozyma auris and Candida parapsilosis were isolated from apple peels. Moreover, although rarely, dematiaceous fungi such as Exophiala dermatitidis and Exophiala phaeomuriformis, which can also be pathogenic for humans and animals, have been identified in apples. The aims of the study were to investigate, the presence of extremotolerant Exophiala species in apples that undergo post-harvest storage processes and are sold in local markets across different regions of Türkiye, as well as the polyaromatic hydrocarbon (PAH) levels in the apples from which these isolates were obtained. Additionally, given their resistance to these molecules, the value of culturing Exophiala species on apples as a biological indicator of PAH pollution and to discuss the findings within the framework of the One Health perspective and to draw attention to this issue were aimed in the study. In the present study, the presence of dematiaceous fungi was investigated in 549 apples collected from local markets in 24 different provinces of Türkiye. Sampling was performed from apple skins using sterile swabs and inoculation was carried out on Sabouraud dextrose agar, Staib agar and Czapek media. Isolates compatible with dematiaceous fungi were subsequently identified by sequencing the rDNA internal transcribed spacer region. Antifungal susceptibility testing against five different triazoles was performed using the CLSI microdilution method. Furthermore, benzo[a]anthracene, benzo[b]fluoranthene, benzo[a] pyrene, and chrysene were measured as indicators to determine the amount of polycyclic aromatic hydrocarbons (PAHs) in the skins of apples from which dematiaceous fungi were recovered. In this study, E.phaeomuriformis was identified in four apples (0.7%). These isolates were detected in the provinces of Ankara, Antalya (Finike district), Kayseri, and Kars (Sarıkamış district). Antifungal susceptibility testing was performed for three isolates, and low MIC values were found for all triazole antifungals except fluconazole.. The levels of the four compounds, considered primary environmental pollutants were determined to be high in the skins of all four apples according to the European Union and Turkish Food Codex limits. This suggests that E.phaeomuriformis, which is known to utilize aromatic hydrocarbons as a carbon source, could be used as a biological indicator of PAH pollution. Additionally, apple skins were considered to represent an oligotrophic habitat. In conclusion, beyond food safety, the need to improve and strengthen public health services is evident.