Lysinbased

Lysin-based refers to therapeutics and products derived from bacteriophage lysins, enzymes that degrade peptidoglycan in bacterial cell walls. These proteins are used as targeted antibacterials, offering rapid bacteriolysis with potential specificity for particular species or strains. Lysin-based approaches encompass native enzymes, engineered variants, and formulations for clinical or industrial use.

Mechanism and scope: Most lysins are endolysins or muralytic enzymes that cleave specific bonds within peptidoglycan. Upon contact with susceptible bacteria, they rapidly disrupt the cell wall and cause osmotic lysis within minutes. In Gram-positive bacteria, lysins readily access the exposed peptidoglycan; for Gram-negatives, outer membranes pose a barrier that must be overcome by engineering or delivery strategies. Activity can be broad or narrowed by design, and combinations with traditional antibiotics can enhance efficacy.

History and examples: Lysin-based antimicrobials emerged from bacteriophage biology and have progressed to clinical and preclinical development. Notable enzymes include PlyC, a potent lysin active against Streptococcus pyogenes, and exebacase (CF-301), investigated for Staphylococcus aureus infections. Engineered chimeric lysins expand host range or improve stability. Applications span topical and systemic uses, including treatment of wound infections, bacteremia, decolonization efforts, and, in some contexts, food-safety biocontrol to reduce pathogenic bacteria on surfaces and in foods.

Advantages and challenges: Benefits include rapid killing, specificity that minimizes disruption to beneficial microbiota, and a reduced propensity for resistance development relative to some antibiotics. Challenges involve potential immunogenicity, variable activity across strains, delivery to the infection site, manufacturing costs, and regulatory hurdles. Lysin-based therapies are often pursued as complements to conventional antibiotics or as localized treatments.