Tyrothricin

Tyrothricin is an antibiotic that belongs to the group of polypeptide antibiotics (actinomycin, bacitracin, polymyxins). Thyrothricin is a mixture of various antibacterially active polypeptides from the groups of tyrocidins (70-80%) and gramicidins (20-30%). The substances are formed by the anaerobic spore-forming Bacillus brevis. Their range of action primarily covers gram-positive bacteria (including methicillin-resistant Staphylococcus aureus strains - MRSA); some gram-negative bacteria and various types of fungi (e.g. Candida albicans) are also covered.
Tyrothricin is classified as a polypeptide antibiotic, which also includes actinomycin, bacitracin and polymyxins.
In the bacterial cell, tyrocidin destroys the osmotic barrier of the cell membrane and causes the release of essential nitrogen and phosphatide-containing substances. Gramicidin causes the formation of additional cation-conducting channels, resulting in a loss of potassium from the bacterial cell. The direct attack on the cell membrane is considered to be one of the reasons why resistance does not occur when thyrothricin is used.

Tyrothricin has no effect on the body's own tissue and therefore does not interfere with the cellular processes involved in wound healing (unlike many antiseptics, which have a cytotoxic effect).

Tyrosur® powder; Tyrosur® gel (hydrogel base)

1. Berditsch M et al (2015) Synergistic effect of membrane-active peptides polymyxin B and gramicidin S on multidrug-resistant strains and biofilms of Pseudomonas aeruginosa. Antimicrob agents Chemother 59:5288-5296.
2. Lang C et al (2016) Tyrothricin--An underrated agent for the treatment of bacterial skin infections and superficial wounds? Pharmacy 71:299-305.
3. Ryu H et al (2015) Investigation of Ion Channel Activities of Gramicidin A in the Presence of Ionic Liquids Using Model Cell Membranes. Sci Rep 5:11935.