Features of the rare pathogen Meyerozyma guilliermondii strain SO and comprehensive in silico analyses of its adherence-contributing virulence factor agglutinin-like sequences

Abstract

Meyerozyma guilliermondii is a rare yeast pathogen contributing to the deadly invasive candidiasis. M. guilliermondii strain SO, as a promising protein expression host, showed 99% proteome similarity with the clinically isolated ATCC 6260 (type strain) in a recent comparative genomic analysis. However, their in vitro virulence features and in vivo pathogenicity were uncharacterized. This study aimed to characterize the in vitro and in vivo pathogenicity of M. guilliermondii strain SO and analyze its Als proteins (MgAls) via comprehensive bioinformatics approaches. M. guilliermondii strain SO showed lower and higher sensitivity towards β-mercaptoethanol and lithium, respectively than the avirulent S. cerevisiae but exhibited the same tolerance towards cell wall-perturbing Congo Red with C. albicans. With 7.5× higher biofilm mass, M. guilliermondii strain SO also demonstrated 75% higher mortality rate in the zebrafish embryos with a thicker biofilm layer on the chorion compared to the avirulent S. cerevisiae. Being one of the most important Candida adhesins, sequence and structural analyses of four statistically identified MgAls showed that MgAls1056 was predicted to exhibit the most conserved amyloid-forming regions, tandem repeat domain and peptide binding cavity (PBC) compared to C. albicans Als3. Favoured from the predicted largest ligand binding site and druggable pockets, it showed the highest affinity towards hepta-threonine. Non-PBC druggable pockets in the most potent virulence contributing MgAls1056 provide new insights into developing antifungal drugs targeting non-albicans Candida spp. Virtual screening of available synthetic or natural bioactive compounds and MgAls1056 deletion from the fungal genome should be further performed and validated experimentally.

Communicated by Ramaswamy H. Sarma

Keywords:

• Meyerozyma guilliermondii
• stress tolerance
• biofilm
• zebrafish embryos toxicity test
• agglutinin-like sequence

Acknowledgement

SJL thanks Universiti Putra Malaysia for supporting him via Graduate Research Fellowship (GRF).

Ethics approval and consent to participate

The use of zebrafish for toxicity test was approved by the Institutional Animal Care and Use Committee (IACUC), Universiti Putra Malaysia (UPM/IACUC/AUP-R044/2022).

Availability of data and materials

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Consent for publication

Not relevant.

Competing interest

The authors have no relevant non-financial interests to disclose.

Author contributions

Si Jie Lim: Conceptualization; Data curation; Formal Analysis; Investigation; Methodology; Software; Validation; Visualization; Writing—Original Draft Preparation; Writing—Review & Editing. Noor Dina Muhd Noor: Supervision; Resources, Writing—Review & Editing. Suriana Sabri: Supervision, Writing—Review & Editing. Mohamad Shukuri Mohd. Ali: Supervision, Writing—Review & Editing; Abu Bakar Salleh: Writing—Review & Editing. Siti Nurbaya Oslan: Conceptualization; Funding Acquisition; Project Administration; Resources; Supervision; Writing—Review & Editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Universiti Putra Malaysia via the Putra Graduate Initiative (IPS) [GP-IPS/2022/9723000] which was awarded to the corresponding author (SNO).