Prevalence, pattern of disease and antimicrobial susceptibility of Candidozyma auris in the greater Pretoria region from 2021 to 2024

Abstract

Background: Candidozyma auris has emerged as a nosocomial pathogen in South Africa, characterised by multidrug resistance and environmental persistence.
Objectives: This study aimed to describe the prevalence, disease patterns, and antifungal susceptibility patterns of C. auris isolates recovered from public-sector healthcare facilities in the greater Pretoria region from 2021 to 2024.
Method: A retrospective laboratory-based surveillance study was conducted using data from the National Health Laboratory Service Tshwane Academic Division laboratory. Isolates were classified as invasive or non-invasive based on specimen source. Temporal trends in antifungal minimum inhibitory concentrations (MICs) were analysed using interval-censored regression.
Results: A total of 592 C. auris isolates were identified. Blood cultures were the most frequent specimen source overall, comprising 237 isolates (40.03%). Intravascular catheter tip isolates predominated in 2023 and 2024, with 48 and 72 isolates, respectively. The proportion of invasive isolates declined from 56.8% to 40.8% over the study period. Among tested isolates, fluconazole resistance exceeded 99%. Resistance to amphotericin B and echinocandins was uncommon, with eight total isolates identified. Decreasing MIC trends were observed for amphotericin B (β = −0.059 per year; p = 0.012) and micafungin (β = −0.081 per year; p = 0.026).
Conclusion: Candidozyma auris remains established in the public-sector within the greater Pretoria region. There is a shift from invasive bloodstream infections towards non-invasive, device-associated isolates. Fluconazole resistance remained high while amphotericin B and echinocandins retained good in vitro activity.
Contribution: This study contributes to the knowledge of C. auris in the greater Pretoria region, providing insight into epidemiology and antifungal susceptibility.