Candida tropicalis is the fourth leading cause of candidemia in Turkey. Although C. tropicalis isolates from 1997 to 2017 were characterized as fully susceptible to antifungals, the increasing global prevalence of azole-non-susceptible (ANS) C. tropicalis and the association between high fluconazole tolerance (HFT) and fluconazole therapeutic failure (FTF) prompted us to re-evaluate azole susceptibility of C. tropicalis in Turkey. In this study, 161 C. tropicalis blood isolates from seven clinical centers were identified by ITS rDNA sequencing, genotyped by multilocus microsatellite typing, and tested for susceptibility to five azoles, two echinocandins, and amphotericin B (AMB); antifungal resistance mechanisms were assessed by sequencing of ERG11 and FKS1 genes. The results indicated that C. tropicalis isolates, which belonged to 125 genotypes grouped into 11 clusters, were fully susceptible to echinocandins and AMB; however, 18.6% of them had the ANS phenotype but only two carried the ANS-conferring mutation (Y132F). HFT was recorded in 52 isolates, 10 of which were also ANS. Large proportions of patients infected with ANS and HFT isolates (89 and 40.7%, respectively) showed FTF. Patients infected with azole-susceptible or ANS isolates did not differ in mortality, which, however, was significantly lower for those infected with HFT isolates ( P = 0.007). There were significant differences in mortality ( P = 0.02), ANS ( P = 0.012), and HFT ( P = 0.007) among genotype clusters. The alarming increase in the prevalence of C. tropicalis blood isolates with ANS and HFT in Turkey and the notable FTF rate should be a matter of public health concern.

Objectives We evaluated the epidemiology of candidemia among COVID-19 patients admitted to intensive care units (ICUs). Methods We conducted a retrospective multicenter study in Turkey between April- December 2020. Results Twenty-eight of 148 enrolled patients developed candidemia, yielding an incidence of 19% and incidence rate of 14/1,000 patient-days. The probability of acquiring candidemia at 10, 20 and 30 days of ICU admission was 6%, 26% and 50%, respectively. Over 80% of patients received antibiotics, corticosteroid and mechanical ventilation. Receipt of a carbapenem (odds ratio and 95% confidence interval (OR, 95% CI) of 6.0 (1.6–22.3), P=0.008), central venous catheter (4.3 (1.3–14.2), P=0.02) and bacteremia preceding candidemia (6.6 (2.1–20.1), P=0.001) were independent risk factors for candidemia. Mortality rate did not differ between patients with and without candidemia. Age (1.05 (1.01–1.09), P=0.02) and mechanical ventilation (61 (15.8–234.9), P<0.0001) were independent risk factors for death. Candida albicans was the most prevalent species overall. In Izmir, C. parapsilosis accounted for 50% (2/4) of candidemia. Both C. parapsilosis isolates were fluconazole non-susceptible, harbored Erg11-Y132F mutation, and were clonal based on whole-genome sequencing. The two infected patients resided in ICUs with ongoing outbreaks due to fluconazole-resistant C. parapsilosis. Conclusions Physicians should be aware of the elevated risk for candidemia among COVID-19 patients requiring ICU care. Prolonged ICU exposure and ICU practices rendered to COVID-19 patients are important contributing factors to candidemia. Emphasis should be placed on heightened infection control in the ICU, and developing antibiotic stewardship strategies to reduce irrational antimicrobial therapy.