Biosynthesis and Engineered Overproduction of Everninomicins with Promising Activity against Multidrug-Resistant Bacteria

Ribosome-targeting oligosaccharides, everninomicins (EVNs),
are
promising drug leads with a unique mode of action distinct from that
of currently used antibiotics in human therapy. However, the low yields
in natural microbial producers hamper an efficient preparation of
EVNs for detailed structure–activity relationship analysis.
Herein, we enhance the production of EVNs by duplicating the biosynthetic
gene cluster (BGC) in Micromonospora sp. SCSIO 07395
and thus obtain multiple EVNs that are sufficient for bioactivity
evaluation. EVNs (1–5) are shown
to significantly inhibit the growth of multidrug-resistant Gram-positive
staphylococcal, enterococcal, and streptococcal strains and Gram-negative
pathogens Acinetobacter baumannii and Vibrio cholerae, with micromolar to nanomolar potency,
which are comparable or superior to vancomycin, linezolid, and daptomycin.
Furthermore, the BGC duplication strategy is proven effective in stepwisely
improving titers of the bioactive EVN M (5) from the
trace amount to 98.6 mg L–1. Our findings demonstrate
the utility of a bioengineering approach for enhanced production and
chemical diversification of the medicinally promising EVNs.