Unmasking the potential as antibiotic makers of three Streptomyces strains isolated in a high-altitude ecosystem in Colombia

Abstract

The current threat of antimicrobial resistance, the surge in antimicrobial compounds rendered obsolete and the slow emergence of new classes of antibiotics havetriggeredan urgent call for novel alternatives to treat infectious diseases. The vast microbial diversity of unexplored environments and the chemical and structural variety of specialised metabolites within it stand as one of the central points to tackle this challenge. This work focuses on the exploration of the potential for antimicrobial compounds in three new Streptomyces strains – Streptomyces sp. CG885, Streptomyces sp. CG893 and Streptomyces sp. CG926- isolated in the Natural National Park Los Nevados (Colombia) and with proved production of active metabolites against several ESKAPE pathogens. To this purpose, we constructed a 16S rRNA phylogenetic tree and studied the specialised metabolite potential of these isolates using a genome mining approach [1] to predict the presence of putative Biosynthetic Gene Clusters (BGCs). Findings from this bioinformatic prediction were linked with analysis from active extracts obtained through agar plate extraction to inform prioritization of clusters. So far, the computational analysis has predicted between 68 to 93 specialised metabolite BGCs for each strain. Interestingly, most of these compounds show less than 15 % similarity to any known compound in the database and around 69 clusters seem related to previously uncharacterised RiPPs, NRPS and PKS. Further work will focus onthe validation and study of those clusters linked to compounds with potential in clinical development.