Objective: Candida parapsilosis species complex and Lodderomyces elongisporus may have differences in terms of their virulence, prevalence, and antifungal susceptibility profiles. These species are difficult to identify with biochemical methods. Therefore, there is a need for more efficient identification methods in terms of time, cost, and applicability. This study aims to evaluate the diagnostic performance of the MALDI-TOF MS method in discriminating between isolates belonging to the C. parapsilosis species complex and L. elongisporus. Method: In the current study, a total of 32 reference strains, including the C. parapsilosis (n=8), Candida orthopsilosis (n=7), Candida metapsilosis (n=6), and L. elongisporus (n=11) species were identified using the MALDI-TOF MS method. Results: The species names of 31 (93.7%) isolates belonging to the C. parapsilosis species complex and L.elongisporus were correctly identified. Twenty four isolates including eight (100%) C. parapsilosis, five (83%) C. metapsilosis, five (71%) C. orthopsilosis, and six (54%) L. elongisporus isolates were identified with score values ranging from 1.7 to 2.14. According to the secure identification reference score of ≥ 1.7, the sensitivity and specificity of the MALDI-TOF MS method were determined as 54.5–100% and 96.3–100%, respectively. Conclusion: Although the MALDI-TOF MS method has been shown to be effective in the rapid molecular phenotypic diagnosis of species that were difficult to discriminate using biochemical methods such as C. parapsilosis species complex and L. elongisporus, there is a clear need to optimize the method and develop a larger MS library for species-level identification within secure score ranges.
Evaluation of Molecular Epidemiology, Clinical Characteristics, Antifungal Susceptibility Profiles, and Molecular Mechanisms of Antifungal Resistance of Iranian Candida parapsilosis Species Complex Blood Isolates
