Molecular characterization of Candida parapsilosis species complex in niches of the oral cavity in a cohort of patients from Argentina with different oral and dental clinical manifestations

Candida parapsilosis is considered to be a complex of three species due to genetic heterogeneity. Currently, it is the second most isolated yeast in bloodstream infections and oral cavity sites with C. parapsilosis sensu stricto and C. metapsilosis being the species mostly recovered from oral niches in both healthy and immunecompromised patients respectively. Disparity in antifungal susceptibility has been reported among species of this complex, while no data on distribution and behavior in the oral cavity has been reported in Argentina. Objective: To molecularly characterize a collection of isolates from Argentina, phenotypically identified as C. parapsilosis from different oral niches, in a cohort of patients with different oral and dental clinical conditions. Methodology: This experimental study used 31 yeasts phenotypically recognized as C. parapsilosis and recovered for molecular characterization by end-point PCR using specific primers. The in vitro sensitivity of isolates against azoles, echinocandins, amphotericin and flucytosine was evaluated by automated Vitek2 system and MIC (Minimum Inhibitory Concentration) in line with CLSI (Clinical and Laboratory Standards Institute) M27-A3 guidelines. Results: All isolates, 100% (31/31), were positive for C. parapsilosis sensu stricto species. Of these, 77.4% were recovered in oral inflammatory conditions, and 94.7% of the strains analyzed for antifungal susceptibility profile showed favorable response to all drugs tested. Conclusions: C. parapsilosis sensu strictois a common colonizing of the oral mucosa under pathological conditions, and generally shows favorable response to antifungal agents commonly used in clinical practice, but with a tendency to lower responsiveness to azoles and echinocandins.