Eight-year surveillance of Candida albicans bloodstream infections in an ICU in Turkey

Background and Purpose: Although the distribution of Candida species has shifted over the past three decades, Candida albicans remains the leading cause of nosocomial bloodstream infections. Materials and Methods: This study examined the genetic diversity and antifungal susceptibility of 174 independent C. albicans bloodstream isolates obtained from intensive care unit patients in Turkey. Microsatellite analysis across five loci identified 21 allelic genotypes for elongation factor 3 (CEF3), 12 for carbonic anhydrase III (CAIII), 11 for LOC4, 11 for zinc finger transcription factor-1 (ZNF1), and 9 for killer toxin-resistance protein-6 (KRE6). The multiplex analysis yielded 104 different multi-loci allelic combinations for the 174 strains analyzed, resulting in a discriminatory power of 0.98. Results: Locus-by-locus microsatellite analysis revealed that certain C. albicans strains from the intensive care unit shared identical genotypes. The geometric mean minimum inhibitory concentrations of antifungal agents, in ascending order, were 0.02 mg/L for itraconazole, voriconazole, and posaconazole, 0.03 mg/L for anidulafungin, 0.13 mg/L for caspofungin, 0.20 mg/L for flucytosine, 0.62 mg/L for fluconazole, and 0.67 mg/L for amphotericin B. Conclusion: Findings showed considerable genetic diversity among bloodstream C. albicans isolates, while antifungal resistance remained uncommon. No significant association was observed between antifungal susceptibility and the genotypes analyzed. The presence of identical genotypes among certain strains points to an endogenous origin and a potential common source of infection within the hospital, warranting further investigation.