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.

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.

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.

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