Species Spectrum and Susceptibility Profiles of Yeasts Isolated From Critical Care Unit Patients in a University Hospital

Abstract

Background With the worldwide increase in yeast infections, especially in high-risk patients, comes an increase in varying patterns of antifungal drug resistance among yeast, specifically Candida species, which becomes an obstacle to effective therapy. This underscores the need for more information on etiological agent and species distribution that could drive treatment recommendations, given the differences in susceptibility to antifungal armamentarium among yeast species. This study aimed to identify the species spectrum and antifungal susceptibility profiles of isolated yeast and assess potential factors associated with colonization and/or infections among critically ill patients. Methodology This was an 11-month retrospective cohort study performed using isolated yeast organisms from patients admitted to the Critical Care Units (CCU) at a university hospital. Standard microbiological techniques were performed on all archived samples from those patients for laboratory culture and determination of yeast identity. Antifungal susceptibility testing was conducted using the VITEK 2 compact system to fluconazole, voriconazole, amphotericin B, flucytosine, caspofungin, and micafungin. Medical records were reviewed retrospectively. Data analysis was done using the R software. Results Among the 250 enrolled critically ill patients, 180 yeast isolates (from carriage and clinical samples) were recovered. Non-albicans Candida species were the most frequent isolates (86.7 percent), followed by Candida albicans (12.2 percent), and yeasts other than Candida (1.1 percent). A noteworthy resistance pattern to fluconazole and voriconazole was seen among Candida parapsilosis; overall resistance to the other tested antifungals was low. Previous antibiotic therapy (aOR=1.89,95%CI 1.06-3.39, P= 0.032) was identified as an independent risk factor for colonization while previous antifungal therapy (aOR=4229.22 ,95%CI 120.89-6346317.47, P= 0.001) and colonization (aOR=13.86 95% CI 1.59-528.43, P=0.049) were significantly associated with infection. Compared with non-colonized non-infected patients, independent risk factors associated with colonized-infected patients were CCU length of stay (OR=1.08,95% CI 1.01-1.16, xi P=0.023), prior antifungal therapy (OR=172.76,95% CI 18.07-12678.34, P<0.001), and neoplasm (OR=27.41,95% CI 2.36-2310.28, P=0.030). Conclusion With shifting patterns of epidemiology, this study emphasizes the importance of continued surveillance, antifungal stewardship, and infection prevention and control measures, a timely reminder that pathogenic yeasts deserve equal attention in the new era of emerging infectious diseases