# Identification of Candida parapsilosis sensu lato and antifungal susceptibility testing of candidemia patients in a tertiary-care hospital in Malaysia

## TL;DR

This study identifies different types of Candida parapsilosis in a Malaysian hospital and tests their resistance to antifungal drugs, showing most remain sensitive but some show early resistance.

## Contribution

The study provides new insights into the subspecies distribution and antifungal resistance patterns of C. parapsilosis in a Malaysian hospital setting.

## Key findings

- Three subspecies of C. parapsilosis were identified: C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis.
- Most isolates were susceptible to antifungals, but some resistance to itraconazole was observed.
- The study emphasizes the importance of molecular identification and antifungal susceptibility testing for managing candidemia.

## Abstract

Candidemia is the fourth most common nosocomial bloodstream infection and the most prevalent nosocomial fungal infection. Candida parapsilosis complex is the second most frequently identified species from blood samples in different countries worldwide, exceeding the prevalence of Candida albicans in some hospitals. Proper conventional identification of C. parapsilosis to subspecies level and confirming this identification using molecular methods such as amplifying and sequencing the internal transcribed spacer–polymerase chain reaction (ITS-PCR) help promptly in final diagnosis of candidemia. In addition, antifungal susceptibility testing (AFST) is becoming mandatory for each individualized sample; a reliable estimation of antifungal susceptibility of Candida causing bloodstream infections is increasingly important to track changes in the antifungal sensitivity/resistance of Candida species and define the burden of antifungal-resistant strains. Here, molecular research was conducted to identify the subspecies of C. parapsilosis and identify patterns of antifungal sensitivity/resistance in a tertiary-care hospital in Malaysia. This study involved a total of 50 C. parapsilosis complex isolates recovered from catheters and blood cultures of patients. Subspecies identification was conducted by conventional methods and confirmed by ITS-PCR, a molecular-based technique. Antifungal susceptibility to azoles, amphotericin B, and echinocandins was tested by E-test method, and results were interpreted according to Clinical and Laboratory Standards Institute clinical breakpoints. Three different subspecies of C. parapsilosis complex were identified: 40 C. parapsilosis sensu stricto, 9 Candida orthopsilosis, and 1 Candida metapsilosis. Most of the strains were susceptible to all antifungals studied, with only a few resistant cases observed. However, despite the limited number of resistant isolates, this study highlights the continuous need to conduct species identification and AFST studies to assess and monitor the growing burden of candidemia, control the effect of potential antifungal resistance, and implement regional surveillance programs to prevent further rise in candidemia rates. Therefore, it is of substantial significance to carry out such types of studies in different countries all over the world to understand the great burden of candidemia and emergence of resistant strains. Early diagnosis of fungal infections in general and candidemia specifically is of essential importance for the proper treatment, prevention, and management of nosocomial fungal infection, such as catheter-related bloodstream infections.

Candida parapsilosis is an emerging cause of bloodstream infections in hospitals, particularly in vulnerable patients using catheters or medical devices. These infections are serious and can be difficult to treat, especially if the yeast becomes resistant to common antifungal medications. In this study, we examined Candida samples from a Malaysian hospital to identify the specific types of C. parapsilosis and test their resistance to antifungal drugs. We found that most strains were still sensitive to treatment, but some showed early signs of resistance, especially to itraconazole. This work highlights the urgent need for hospitals to regularly monitor fungal infections and adjust treatment plans based on up-to-date lab testing. Understanding which strains are present and how they respond to drugs helps doctors choose the most effective treatment, improves patient outcomes, and supports infection control efforts to prevent future outbreaks of resistant fungal infections.