Multi-Strain and -Species Investigation of Volatile Metaboli tes emitted from Planktonic and Biofilm Candida cultures - DATA

<em>Candida parapsiliosis</em> is a prevalent neonatal pathogen that attains its virulence through its strain-specific ability to form biofilms. The use of volatilomics, the profiling of volatile metabolites from microbes is a non-invasive, simple way to identify and classify microbes and has shown great potential for pathogen identification. Although <em>C. parapsiliosis</em> is one of the most common clinical fungal pathogens, its volatilome has never been characterised. In this work, planktonic volatilomes of ten clinical strains of <em>C. parapsilosis </em>were analysed, along with a single strain of <em>Candida albicans. </em>Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry was employed to analyse the samples. Species-, strain-, and media- influences on the fungal volatilomes were investigated. 24 unique metabolites from the examined <em>Candida spp.</em> (22 from <em>C.</em> <em>albicans</em>; 18 from<em> C</em>. <em>parapsilosis</em>) were included in this study. Chemical classes detected across the samples included alcohols, fatty acid esters, acetates, thiols, sesquiterpenes and nitrogen-containing compounds. <em>C. albicans </em>volatilomes were most clearly discriminated from <em>C. parapsilosis </em>based on the detection of unique sesquiterpene compounds. The effect of biofilm formation on the <em>C. parapsilosis</em> volatilomes was investigated for the first time by comparing volatilomes of a biofilm-positive strain and a biofilm-negative strain over time (0 – 48 hours) using a novel sampling approach. Volatilomic shifts in the profiles of alcohols, ketones, acids, and acetates were observed specifically in the biofilm-forming samples and attributed to biofilm maturation. This work highlights species-specificity of <em>Candida</em> volatilomes and also marks the clinical potential for volatilomics for non-invasively detecting fungal pathogens. Additionally, the range of biofilm-specificity across microbial volatilomes is potentially far-reaching and therefore characterising these volatilomic changes in pathogenic fungal and bacterial biofilms could lead to novel opportunities for detecting severe infections early. <br> <br>