Ayşe Sultan Karakoyun

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.

This study investigated the treatment outcomes of 91 patients with chronic and recalcitrant dermatophytosis from 20 hospitals in Türkiye between June 2022 and March 2024, as well as the in vitro antifungal susceptibility and squalene epoxidase ( SQLE ) substitution profiles of the dermatophytes obtained from these patients. Molecular identification by sequencing 91 isolates, revealed 76 Trichophyton mentagrophytes ITS genotype VIII (TmVIII; also known as T . indotineae ) isolates, 13 Trichophyton rubrum , one Trichophyton tonsurans , and one Microsporum canis . The Phe397Leu substitution predominated in the SQLE , and Tyr414His co-occurred in nine TmVIII isolates. Five novel substitutions were observed in TmVIII. Among 13 T . rubrum isolates, three showed different SQLE substitution patterns compared to the wild-type strain. EUCAST antifungal susceptibility testing revealed high minimum inhibitory concentrations (MICs) for terbinafine (TRB) (> 0.25 mg/L) and for fluconazole (FLZ) (≥ 16 mg/L), indicating resistance in most TmVIII isolates. Of the 91 patients, 83 responded to FLZ, itraconazole (ITZ), TRB, or voriconazole-based regimens. While adjunct therapy with FLZ and resveratrol (RES) led to improvement in 28/29 patients despite their high in vitro inhibition concentrations, ITZ and curcumin (CUR) therapy was successful in 3/3 patients. However, the in vitro efficiency of CUR could not be evaluated. These findings highlight the local occurrence of specific SQLE substitutions, underscore the importance of EUCAST MIC testing combined with SQLE sequencing for surveillance, and support further evaluation of RES and CUR as an adjunct in TRB-resistant TmVIII.

Candidemia is a major global health challenge, with Candida albicans being the most common causative agent. Since antifungal drugs may promote resistance, regular epidemiological studies are required. Nonetheless, microbiological and clinical data on C. albicans in Türkiye are limited. Therefore, we assessed data from C. albicans cases in a tertiary care hospital in Türkiye. Among 171 enrolled patients, the overall mortality rate was 66.7%. Univariate analysis showed that age, intensive care unit (ICU) admission, central venous catheterization, mechanical ventilation, hemodialysis, diabetes mellitus, Coronavirus disease 2019 (COVID-19) infection, steroid use, and hyperalimentation were associated with mortality. Multivariate logistic regression showed that age, ICU admission, steroid use and hyperalimentation were independently associated with mortality. In Cox regression, age, ICU admission, prior antifungal use, and absence of antifungal treatment after candidemia were independently associated with decreased survival. Fluconazole (FLC) was the most frequently used antifungal, and patients treated with FLC + amphotericin B or FLC + echinocandin had the best survival rates. All 171 isolates were susceptible to all tested antifungals. Our findings show high mortality rates and reveal mortality-associated factors. Candida albicans remains susceptible to all antifungals; therefore, timely diagnosis and appropriate antifungal treatment can enhance survival and clinical outcomes.

Candidemia is a major global health challenge, with Candida albicans being the most common cause. Since antifungal drugs may promote antifungal resistance, regular epidemiological studies are required. Nonetheless, microbiological and clinical data on C. albicans Türkiye is lacking. Therefore, we assessed data from C. albicans cases in a tertiary care hospital in Türkiye. Among 171 enrolled patients, the overall mortality rate was 66.7%. Univariate analysis showed that age, intensive care unit (ICU) admission, central venous catheter, mechanical ventilation, presence of hemodialysis, diabetes mellitus, COVID-19 infection, steroid use, and hyperalimentation were associated with mortality. Multivariate logistic regression showed that age, ICU admission, steroid use and hyperalimentation were independently associated with mortality. In the Cox regression, age, ICU admission, prior antifungal use, and no antifungal use after candidemia were independently associated with decreased survival. Fluconazole (FLC) was the most used antifungal, and patients treated with FLC+amphotericin B or FLC+echinocandin had the best survival rates. All 171 isolates were susceptible to all tested antifungals. The strains were all wild-type, showing no acquisition of antifungal resistance. Our findings show high mortality rates and reveal mortality-associated factors. Candida albicans remains susceptible to all antifungals. Therefore, timely diagnosis and antifungal treatment can enhance survival and clinical success.

Trichophyton indotineae, formerly known as T. mentagrophytes internal transcribed spacer (ITS) genotype VIII, has been recognized over the last decade due to its high virulence and resistance to treatment. Its accurate identification in routine mycology laboratories remains challenging, as it shares phenotypic traits and substantial rDNA ITS similarity with T. mentagrophytes and T. interdigitale. This study aimed to identify more divergent and stable sequences via whole-genome comparisons between T. indotineae and T. interdigitale to facilitate highly specific targeting of T. indotineae using a validated quantitative polymerase chain reaction (qPCR)-based method. Our whole-genome comparison revealed at least 22 unique sequences of T. indotineae compared to T. interdigitale and revealed the divergence of the former from the reference genomes of other Trichophyton species. Among these, a 499 bp segment was identified as the most genetically distinct sequence within the T. indotineae genome. Seventy-three dermatophyte strains [T. indotineae (n = 66), non-T. indotineae (n = 7)], were tested using our qPCR assay targeting the above-mentioned stable 499-bp region. Regarding analytical performance, our T. indotineae-specific qPCR assay exhibited high sensitivity (93.3%) and specificity (100%), with a detection limit of ~ 15 genomic copies. Our approach has the potential to establish highly sensitive and specific qPCR assays without relying on specialized assay designs for single nucleotide polymorphisms in the ITS or other loci. This approach offers a practical solution for updating molecular diagnostics, particularly for novel taxa such as T. indotineae, for which limited gene data are available in public databases.

Clinical and mycological data are essential for the optimal management of patients with Candida vaginitis (CV), particularly in cases of (i) azole-resistant C. albicans vaginitis, (ii) recurrent CV, and (iii) CV in pregnant women. The present retrospective single-center study investigated the antifungal activity of six commonly used antifungals against randomly selected vaginal isolates recovered from 68 pregnant women in Adana, Türkiye, including C. albicans, petite C. glabrata, non-petite C. glabrata, and C. krusei, using the disk diffusion method at pH 4 and 7. Furthermore, the antifungal activities of fluconazole and itraconazole were also assessed using the broth microdilution method. For all isolates, the mean inhibition zone diameters were narrower for itraconazole and ketoconazole and larger for miconazole at pH 4 than pH 7 (p < 0.05). For nystatin, zone diameters were wider in C. albicans and petite C. glabrata at pH 4 (p < 0.001 and p < 0.001). Remarkably, clotrimazole was more active at pH 4 than at pH 7, except against non-petite C. glabrata isolates. Based on the broth microdilution results, the resistance rate was higher at pH 4 than at pH 7 in all isolates. Candida glabrata petite isolates exhibited MIC values 2 to 5 times higher than those of the non-petite isolates for both fluconazole and itraconazole. This study highlights the potent activity of topical antifungals (miconazole, nystatin, and clotrimazole) for the treatment of CV in pregnant women and highlights the need to identify petite and non-petite mutants of vaginal C. glabrata isolates to obtain more reliable data and for antifungal susceptibility testing prior to decision-making. The results of the two antifungal susceptibility methods were compared for C. albicans and C. glabrata isolates, and the reliability of the disk diffusion test was discussed.

Vaginal candidiasis (VC) is a prevalent condition among women of reproductive age and poses a significant global public health challenge. However, the disease is often diagnosed and treated without mycological information. We investigated the epidemiology, laboratory diagnostics, and antifungal susceptibility of VC. We included 300 women from Çukurova University Obstetrics and Gynecology outpatient clinic in Adana, Türkiye. Participants underwent a health survey and provided vaginal swab samples for microscopic examination and fungal culture. The microscopic analysis involved wet-mount and gram-stained slides, whereas fungal identification involved CHROMAgar Candida, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and real-time polymerase chain reaction high-resolution melting analysis (RT-PCR HRMA). Antifungal susceptibility tests were conducted at pH 7 and 4 using the CLSI document M44-A2. Of the 106 women with positive fungal cultures, 86.8% were diagnosed with VC, whereas 13.2% showed Candida colonization. Among those with VC, 55.4% had acute and 44.6% had recurrent VC; a family history of allergies increased the risk for both types. We recovered 115 yeast isolates, predominantly C. albicans, C. glabrata, and C. krusei. Diagnostic accuracy of CHROMAgar Candida was 91.3% for the most common isolates, and HRMA was consistent in differential diagnosis. Antifungal resistance varied with pH; susceptibility to fluconazole, itraconazole, and ketoconazole decreased at pH 4, whereas susceptibility to miconazole increased. Our findings underscore the need for a diagnostic algorithm and enhanced collaboration between clinicians and microbiologists to improve VC management. Recommendations include using Gram staining, CHROMAgar Candida, MALDI-TOF MS, and antifungal susceptibility tests at both pH levels.

Candida krusei also known as Pichia kudriavzevii is a potentially multidrug-resistant yeast because it is intrinsically resistant to fluconazole and develops acquired resistance to echinocandins and polyenes. Here, we aim to provide a better understanding of the epidemiology and transmission modes of C. krusei infections by comparing invasive bloodstream (n = 35) and non-invasive vaginal (n = 20) C. krusei isolates. The genetic relatedness of the isolates was assessed using a newly described short tandem repeat (STR) analysis and their sensitivity to eight antifungal compounds was evaluated by antifungal susceptibility testing using the CLSI microbroth dilution method. All C. krusei isolates revealed unique STR genotypes, indicating the absence of clonal transmission in the study group. Furthermore, no drug-resistant or non-wild-type isolates were identified. Our findings demonstrated high resolution of STR genotyping for the detection and simultaneous genetic analysis of multiple C. krusei strains in clinical samples and excellent in vitro activity of common antifungal agents against invasive strains. To gain insight into the mode of transmission and resistance development of C. krusei, we compared invasive bloodstream C. krusei isolates with non-invasive vaginal isolates using genotyping and susceptibility testing. All isolates demonstrated unique genotypes and no antifungal resistance was found, indicating the absence of clonal transmission and a high susceptibility to antifungals.

Ayşe Sultan Karakoyun1, Nevzat Ünal1,2, Banu Metin3, Esra Yıldırım Servi3, Bram Spruijtenburg4,5, Muhammed Alper Özarslan6, Ramazan Gümral7, Aylin Döğen8,