On the potential role of naturally occurring carboxylic organic acids as anti-infective agents. Opportunities and challenges

: Carboxylic organic acids are intermediates of central carbon metabolic pathways (e.g. acetic, propionic, citric and lactic acid) long known to have potent antimicrobial potential, mainly at acidic pHs. The food industry has been leveraging those properties for years utilizing many of these acids as preservatives to inhibit growth of pathogenic and/or spoilage fungal and bacterial species. A few of these molecules (the most prominent being acetic acid) have been used as antiseptics since Hippocratic medicine, mainly to treat infected wounds in burn patients. With the growth of antibiotic therapy, the use of carboxylic acids (and other chemical antiseptics) in clinical settings lost relevance; however, with the continuous emergence of multi-antibiotic/antifungal resistant strains the search for alternatives has intensified. This prospective article aims to raise awareness of the potential of carboxylic acids to control infections in clinical settings, considering not only their previous exploitation in this context (which we overview) but also the positive experience of their safe use in food preservation. At a time of great concern with antimicrobial resistance and the slow arrival of new antimicrobial therapeutics to the market, further exploration of organic acids as anti-infective molecules may pave the way to more sustainable prophylactic and therapeutic approaches.