Candida auris is an emerging multidrug-resistant fungus that causes a wide range of symptoms. We report finding 17 cases of C. auris infection that were originally misclassified but correctly identified 27.5 days later on average. Patients with a delayed diagnosis of C. auris had a 30-day mortality rate of 35.2%.
C. auris is an emerging and opportunistic multidrug-resistant human pathogen. It is necessary to strengthen measures to achieve an accurate and quick identification and also to avoid its dissemination. This will require improvements in health and infection control measures, as well as the promotion of antifungal stewardship in healthcare facilities.
Palindromic peptide LfcinB (21–25)Pal: RWQWRWQWR was synthesized by Solid Phase Peptide Synthesis (SPPS‐Fmoc/tBu), purified by Reverse Phase Solid Phase Extraction (RP‐SPE) and characterized by Reverse Phase High Performance Liquid Chromatography (RP‐HPLC) and Matrix‐Assisted Laser Desorption/Ionization‐Time Of Flight Mass Spectrometry (MALDI‐TOF MS). The antifungal activity of LfcinB (21–25)Pal against both ATCC strains and clinical isolates of C. albicans, C. glabrata, C. krusei, C. auris and C. tropicalis was evaluated. The palindromic peptide exhibited fungistatic and fungicidal activity against all yeast evaluated. The antifungal activity was dependent on peptide concentration in all cases. Additionally, LfcinB (21–25)Pal (25–50 μg/mL) combined with fluconazole exhibited a synergistic antifungal effect against C. tropicalis 883 and C. krusei 6258 (resistant to fluconazole). This study showed that the palindromic peptide derived from Lactoferricin B (LfcinB) exhibited significant antifungal activity against Candida spp, suggesting that this peptide could have a therapeutic application solely or in combination with fluconazole.
Background
The introduction of MALDI-TOF MS in the clinical microbiology laboratory has modified the approaches for the identification of fungi. Thanks to this tool, it is possible to identify cryptic species, which possess critical susceptibility patterns. Clinical strains were identified using the MicroScan and MALDI-TOF MS systems. Discrepant results from both methods were investigated using ITS rDNA barcoding. Finally, these isolates were also tested for in vitro susceptibility.
Results
The percentage of agreement between both methods to 498 yeast isolates was of 93.6% (32 discrepant isolates). The concordance of ITS sequencing with MALDI-TOF MS was higher (99%) than that of MicroScan (94%). Several of these discordant yeasts displayed high MICs for antifungal agents.
Conclusions
Our study highlights the need of the MS and molecular approaches such as MALDI-TOF MS and ITS rDNA barcoding for the correct identification of emerging or cryptic yeast species; besides, some of these could be multidrug resistant.
This work was the first experience in the implementation of the MALDI-TOF MS technology in Colombia. We found the first uncommon yeasts including
Candida auris
and we could identify
Trichosporon faecalis
. Our work highlights a clear necessity of an accurate yeast identification as a much more pertinent technique than the susceptibility profiles, because the most unusual yeasts exhibit resistance profiles to the few available antifungals.
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