Detailed Soluble Proteome Analyses of a Dairy-Isolated Enterococcus faecalis : A Possible Approach to Assess Food Safety and Potential Probiotic Value

• Published in: Frontiers in nutrition (Lausanne) Vol. 6; p. 71
• Main Authors: Cirrincione, Simona, Neumann, Bernd, Zühlke, Daniela, Riedel, Katharina, Pessione, Enrica
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 17.05.2019
• Subjects: antibiotic resistance; foodborne bacteria; gel-free proteomics; host interaction; Nutrition; virulence; gel-free proteomics; foodborne bacteria; virulence; antibiotic resistance; host interaction
• ISSN: 2296-861X; 2296-861X
• DOI: 10.3389/fnut.2019.00071

Enterococci are common inhabitants of the gastrointestinal tracts of humans and animals and thanks to their capability to tolerate different environmental conditions and their high rates of gene transfer, they are able to colonize various ecological niches, as food matrices. bacteria are defined as controversial microorganisms. From one side they are used as food starters, bio-control agents and probiotics to improve human or animal health. From the other side, in the last two decades enterococci have emerged as important nosocomial pathogens, because bearing high-level of resistance to antibiotics and several putative virulence factors. In this study, the soluble proteome quantitation data (LC-MS/MS) of the food-isolated strain D27 (dairy-isolate) was compared with the soluble proteome quantitation data of the pathogenic UW3114 (urinary tract infection isolate) and with the one of the health promoting strain Symbioflor1, respectively. The comparison of cytosolic protein expression profiles highlighted statistically significant changes in the abundance of proteins mainly involved in specific metabolic pathways, nutrient transport, stress response, and cell wall modulation. Moreover, especially in the dairy isolate and the clinical isolate, several proteins with potential pathogenic implications were found, such as serine proteases, von Willebrand factor, serine hydrolase with beta lactamase activity, efflux transporter, and proteins involved in horizontal gene transfer. The analysis of the extracellular proteome provided interesting results concerning proteins involved in bacterial communication, such as pheromones and conjugative elements and also proteins able to interact with human components. The phenotypic characterization evaluating (i) biofilm formation (ii) hemolytic activity on blood agar plates (iii) protease activity (iv) gelatinase (v) antibiotic resistance pattern, enabled us to elucidate the risks associated with the poor characterized foodborne D27.