Molecular Detection of Candida aaseri in Oral Cavity of Immunocompromised Patients

Abstract

The impaired human immune system, resulting from diabetes mellitus, can lead to the transition of Candida from a commensal to a pathogenic status, causing oral fungal infections. Candida aaseri is a dimorphic yeast with lipolytic activity which has not been previously reported in clinical infections. This study reports an extremely rare oral fungal infection associated with C. aaseri in a patient with type II diabetes mellitus. The patient, a 42-year-old female with diabetes mellitus type II from Basrah, Iraq, was and identified with a fungal oral infection. Swab samples were collected from the patient's oral cavity for microbial investigation and cultured on Sabouraud Dextrose Agar (SDA) at 37°C for 48 hours. The results revealed pure yeast growth. Blue colonies were observed on CHROMagar Candida. The genomic DNA of the isolated yeast was extracted for molecular-level diagnosis, utilizing the mRNA gene's internal transcribed spacer (ITS) region. C. aaseri was the sole yeast species identified in this clinical case. Anti-fungal sensitivity tests indicated that C. aaseri was sensitive to Nystatin, Posaconazole, and Fluconazole while exhibiting significant resistance to Colistin Sulfate. This study represents the first global report of isolating C. aaseri from an oral infection in an immunocompromised patient.