# Azole Resistance in Candida parapsilosis From Patients With Burns in Mexico: A Genomic and Phylogenetic Analysis

## TL;DR

This study analyzes Candida parapsilosis strains from burn patients in Mexico to understand azole resistance patterns and genetic variants.

## Contribution

The study identifies specific genetic mutations linked to azole resistance in C. parapsilosis from clinical isolates in Mexico.

## Key findings

- Most isolates were Candida parapsilosis sensu stricto, with 33% showing fluconazole resistance.
- The ERG11 Y132F variant was common in resistant isolates.
- Two haplotypes were identified through SNP and phylogenetic analysis.

## Abstract

Candida species are common causes of nosocomial infections.
Candida parapsilosis
has emerged as an important pathogen. Mortality rates associated with invasive
C. parapsilosis
infections range from 14.5% to 47%, with azole resistance estimated between 4% and 15%. Resistance mechanisms include mutations in ERG11 that diminish azole binding, upregulation of ergosterol biosynthesis genes due to mutations in regulatory factors like UPC2 and NDT80, and increased efflux pump activity.

Thirty clinical strains of the
C. parapsilosis
complex were isolated from bloodstream cultures, biopsies and catheter tips from hospitalised patients from a major rehabilitation centre in Mexico between June 2011 and August 2016. Minimum inhibitory concentrations for fluconazole, voriconazole, itraconazole, caspofungin, micafungin, anidulafungin and amphotericin B were determined using the broth microdilution method. Whole genome sequencing was conducted using Illumina technology, with subsequent assembly and annotation. Analyses included antifungal resistance variant screening, SNP distance, average nucleotide identity and phylogenetic comparisons with publicly available genomes.

Most strains (96.7%, 29/30) were identified as
C. parapsilosis
sensu stricto, predominantly isolated from blood. Thirty‐three percent of isolates showed phenotypic resistance to fluconazole. The SNP‐distance and maximum‐likelihood phylogenetic analyses revealed two distinct haplotypes and the genotype 1: ERG11
WT/Y132F, CDR1
I1287V/I1287V and UPC2
WT/N455D was the most represented (8/10 isolates).

C. parapsilosis
sensu stricto was the predominant species isolated, with a notable proportion exhibiting resistance to FLU and VOR. The Y132F variant in the ERG11 gene was present in most sequenced isolates.