Two decades of mucormycosis: molecular epidemiology and antifungal susceptibility trends in Türkiye

TL;DR

This study analyzed 20 years of mucormycosis cases in Türkiye, revealing trends in infection types, underlying conditions, and antifungal drug effectiveness.

Contribution

The study provides the most comprehensive data on mucormycosis in Türkiye, emphasizing molecular surveillance for antifungal treatment guidance.

Findings

Rhino-cerebral infection was the most common form of mucormycosis, followed by pulmonary disease.

Posaconazole showed greater in vitro activity than amphotericin B against Mucorales fungi.

Cunninghamella species exhibited elevated amphotericin B minimum inhibitory concentrations.

Abstract

Mucormycosis is a life-threatening invasive fungal infection that mainly affects individuals with weakened immune systems. Despite its clinical importance, data from Türkiye on the epidemiology and antifungal susceptibility of fungi belonging to the order Mucorales are scarce. This study aimed to describe the clinical, epidemiological, and mycological features of mucormycosis over a twenty-year period at a tertiary care hospital.

All cases of mucormycosis diagnosed between 2003 and 2022 at Bursa Uludağ University Hospital were retrospectively evaluated. Cases were classified as proven or probable according to international definitions. Molecular identification was based on internal transcribed spacer sequencing. Large subunit ribosomal DNA region sequencing and whole-genome sequencing were performed when necessary. Antifungal susceptibility testing for amphotericin B and posaconazole was performed according to the Clinical and Laboratory Standards Institute M38 guideline. Statistical analyses included chi-square, Fisher’s exact, Spearman’s correlation, and Wilcoxon signed-rank tests.

A total of 187 cases were identified, comprising 134 proven and 53 probable. Rhino-cerebral infection was the most frequent form, followed by pulmonary disease. Hematologic malignancy was the most common underlying condition, and mortality was 52.9 percent. Molecular identification was achieved for 99 isolates, with Rhizopus arrhizus predominant and Rhizomucor pusillus second. Posaconazole exhibited greater in vitro activity than amphotericin B (p < 0.001), while Cunninghamella species showed elevated amphotericin B minimum inhibitory concentrations.

This single-center study provides the most comprehensive data on mucormycosis in Türkiye and highlights the importance of molecular surveillance to guide antifungal therapy and monitor regional variations.

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