Mass Spectrometry Proteotyping-Based Detection and Identification of Staphylococcus aureus, Escherichia coli and Candida albicans in Blood

ABSTRACT: Bloodstream infections (BSIs), the presence of microorganisms in blood, are potentially serious conditions that can quickly develop into sepsis and life-threatening situations. When assessing proper treatment, rapid diagnosis is the key; besides clinical judgement performed by attending physicians, supporting microbiological tests typically are performed, often requiring microbial isolation and culturing steps, which increases the time required for confirming positive cases of BSI. The additional waiting time forces physicians to prescribe broad-spectrum antibiotics and empiric treatment, before determining the precise cause of the disease. Thus, alternative and more rapid cultivation-independent methods are needed to improve clinical diagnostics, supporting prompt and accurate treatment and reducing the development of antibiotic resistance. In this study, a culture-independent workflow for pathogen detection and identification in blood samples was developed, using peptide biomarkers and applying bottom-up proteomics analyses, i.e., so-called ”proteotyping”. To demonstrate the feasibility of detection of blood infectious pathogens using proteotyping, Escherichia coli and Staphylococcus aureus were included in the study, as the most prominent bacterial causes of bacteremia and sepsis, as well as Candida albicans, one of the most prominent causes of fungemia. Model systems including spiked negative blood samples, as well as positive blood cultures, without further culturing steps, were investigated. Furthermore, an experiment designed to study the incubation time needed for correct identification of the infectious pathogens in blood cultures was performed. Compared to the MALDI-TOF MS-based approaches, shotgun proteotyping demonstrated higher sensitivity and accuracy, and required shorter incubation time before detection and identification of the correct pathogen could be accomplished.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Escherichia Coli Candida Albicans (yeast) Staphylococcus Aureus

SUBMITTER: Gelio Alves  

LAB HEAD: Roger Karlsson

PROVIDER: PXD023033 | Pride | 2021-07-20

REPOSITORIES: Pride