Risk factors and outcome for bloodstream infections due to fluconazole-resistant Candida parapsilosis: a 22-year single-center retrospective study.

Candidemia ranks among the top causes of nosocomial bloodstream infections, significantly increasing hospital stays and costs. Rapid and effective empirical antifungal therapy is crucial. The Candida parapsilosis species complex, the second most common cause of candidemia, has shown rising fluconazole resistance globally and in our country. Additionally, echinocandins exhibit higher minimum inhibitory concentrations (MICs) for C. parapsilosis, complicating empirical treatment decisions. This retrospective study analyzed 173 C. parapsilosis candidemia cases over 22 years in a tertiary care hospital. We compared 88 fluconazole non-susceptible (minimum inhibitory concentration [MIC] = 4 µg/mL: susceptible dose dependent; MIC ≥ 8 µg/ml resistant) and 85 fluconazole susceptible cases, examining demographics, clinical characteristics, risk factors, and 28-day mortality. Independent risk factors for fluconazole non-susceptibilty included age ≥ 66 years (p = 0.016), central venous catheter use (p < 0.001), total parenteral nutrition (p = 0.003), and colostomy (p = 0.049). Fluconazole non-susceptible cases had lower microbiological cure rates and higher mortality. Mortality in this group was independently associated with microbiological cure failure (p < 0.001). This study highlights the importance of identifying risk factors to estimate the likelihood of resistant pathogens, initiating targeted antifungal therapy, and providing individualized management. Monitoring local resistance patterns is essential to guide empirical therapy. Further multicenter research is needed to validate findings and optimize treatment for fluconazole resistant candidemia. Clinical trial number: Not applicable.