RESUMEN
Candida auris is an emerging multidrug-resistant and opportunistic pathogenic yeast. Whole-genome sequencing analysis has defined five major clades, each from a distinct geographic region. The current study aimed to examine the genome of the C. auris 20-1498 strain, which is the first isolate of this fungus identified in Mexico. Based on whole-genome sequencing, the draft genome was found to contain 70 contigs. It had a total genome size of 12.86 Mbp, an N50 value of 1.6 Mbp, and an average guanine-cytosine (GC) content of 45.5%. Genome annotation revealed a total of 5432 genes encoding 5515 proteins. According to the genomic analysis, the C. auris 20-1498 strain belongs to clade IV (containing strains endemic to South America). Of the two genes (ERG11 and FKS1) associated with drug resistance in C. auris, a mutation was detected in K143R, a gene located in a mutation hotspot of ERG11 (lanosterol 14-α-demethylase), an antifungal drug target. The focus on whole-genome sequencing and the identification of mutations linked to the drug resistance of fungi could lead to the discovery of new therapeutic targets and new antifungal compounds.
RESUMEN
BACKGROUND: Candida haemulonii is an emergent, multi-resistant opportunistic pathogenic yeast that like Candida auris, can be misidentified when conventional diagnostic methods are used. Timely molecular identification using DNA sequence analysis variation in the internal transcriber spacer region, ITS1-ITS4 and the 28S ribosomal DNA gene (28S rDNA), and in vitro antifungal susceptibility assessment can lead to rapid therapeutic success. CASE REPORT: A case of Candida haemulonii candidiasis suffered by a male paediatric patient attended at Federico Gómez Children's Hospital of México City in September 2016 is reported. The isolate was yielded from peripheral blood and central catheter blood specimens. From in vitro antifungal susceptibility data, caspofungin was administered to the patient, who showed clear improvements at the end of antimicrobial administration, and the removal of the central venous catheter. Using a molecular phylogenetic approach, we identified the clinical isolate as C. haemulonii. The clinical isolate has been named as Candida haemulonii ENCB-87 from now on. C. haemulonii ENCB-87 grew well between the temperatures, 28 °C and 35 °C but not at 37 °C in YPD culture medium. The clinical isolate was susceptible to caspofungin, which resulted in therapeutic success for the patient. CONCLUSIONS: C. haemulonii is an emergent, opportunistic pathogen, closely related to C. auris, therefore, the timely and accurate identification and antifungal susceptibility assessments are paramount in generating a robust epidemiology of this emerging Candida species.