Identification of Lytic Enzymes With Activity Against Corynebacterium Species.

Abstract

Corynebacteriales are normal constituents of the human skin microbiota, involved in the metabolism of sweat and sebaceous glands secretions. The resultant compounds are a source of human body malodor. Some species, such as Corynebacterium jeikeium, are also opportunistic pathogens, and can cause systemic infection from colonization of medical devices such as intravascular catheters. Cell lytic enzymes have become effective alternatives to antibiotics and chemical oxidants in eliminating undesirable pathogens. As a baseline for antibacterial enzymatic activity we selected the broadly specific antibacterial enzyme lysozyme. While lysozyme had minimal activity on its own, the activity was significantly potentiated by the addition of a disruptor of the surface lipid layer of the bacterial cell wall, such as the lipase LysB (originating from a mycobacterial bacteriophage) or ethyleneglycol tetraacetic acid. To identify cell lytic enzymes with specific anti-Corynebacterial activity, we used a whole enzyme sequence as a probe to interrogate a custom-built in silico cDNA database of target Corynebacterial species and their bacteriophages. We also used a consensus enzymatically active domain as a probe. We evaluated the antibacterial activity of the thus discovered enzymes under a panel of application-relevant conditions, and determined that the newly identified bacterial autolysin NCBI WP_003861765.1 showed activity comparable to that of lysozyme, and the phage endolysin NCBI SLN03091 showed substantially higher activity than lysozyme and was significantly potentiated in the presence of LysB. As a result, we identified a nonchemical, nonantibiotic route to controlling Corynebacterial viability.