Novel compounds from shark and stingray epidermal mucus with antimicrobial activity against wound infection pathogens.

Abstract

A protective secretion produced by epidermal mucus cells in stingrays is being investigated to understand its role in wound healing and to identify mucus-associated antimicrobial compounds with the potential for development into novel therapeutics to treat wound infection pathogens. Mucus from cownose rays (Rhinoptera bonasus), Atlantic stingrays (Dasyatis sabina), devil rays (Mobula hypostoma) and clearnose skates (Raja eglanteria) contains proteins in the aqueous supernatant and viscous pellet, as well as symbiotic bacteria. While fresh mucus extracted with a magnesium salt of trifluoroacetic acid possesses low but measurable antimicrobial activity, symbiotic bacteria isolated from the mucus consistently demonstrate antibiotic activity in both primary and secondary screens against pathogenic bacterial strains. Many of these strains are active against either MRSA or VRE. Experimental wounding studies result in wounds that heal without infection or inflammation. While a healing timeline based on gross physical appearance of wounds suggests gradual healing over several weeks, histology of biopsied wounds from day 28 and earlier reveals that day 2 wound beds are already covered with a thin epidermis containing mucus cells and a clearly identifiable basal layer over a developing but unstructured dermis.