Genomic Epidemiology of Candida auris in Qatar Reveals Hospital Transmission Dynamics and a South Asian Origin

Area of Science:

• Medical Mycology
• Infectious Diseases
• Genomics

Background:

• Emerging multidrug-resistant fungal pathogen, *Candida auris*, poses a significant global public health threat.
• Increasing incidence of *C. auris* infections worldwide, with easy transmission in healthcare settings.
• Outbreaks reported in the Middle East, including Qatar, but isolate origins remain largely unknown.

Purpose of the Study:

• To determine the epidemiology and identify drug resistance mutations of *Candida auris* in Qatar using whole genome sequencing (WGS).

Main Methods:

• Whole genome sequencing (WGS) of 44 *C. auris* samples from patients and hospital environments in Qatar using Illumina NextSeq.
• Core genome single nucleotide polymorphism (SNP) analysis.

Main Results:

• All sequenced isolates belonged to the South Asian lineage, indicating potential acquisition from foreign healthcare systems.
• Low genetic variability among outbreak isolates in two hospitals (A and B).
• Environmental isolates clustered with clinical isolates; epidemiologically linked isolates clustered together, suggesting patient and environmental transmission routes.
• Detected mutations Y132F and K143R in *ERG11*, associated with increased fluconazole resistance.

Conclusions:

• The findings suggest *C. auris* in Qatar originated from foreign healthcare sources and is transmitted through patients and the hospital environment.
• Identified specific genetic mutations linked to antifungal resistance, providing insights for treatment and control strategies.
• WGS is effective for tracking *C. auris* transmission dynamics and understanding resistance mechanisms.