Antibacterial effects of phage lysin LysGH15 on planktonic cells and biofilms of diverse staphylococci.

In this study, we observed the ability of the phage lysin LysGH15 to eliminate staphylococcal planktonic cells and biofilms formed by Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus hominis All these strains were sensitive to LysGH15, showing reductions in bacterial counts of approximately 4 log units within 30 min after treatment with 20 μg/mL LysGH15, and the minimum inhibitory concentrations (MICs) ranged from 8 μg/mL to 32 μg/mL. LysGH15 efficiently prevented biofilm formation by the four staphylococcal species at a dose of 50 μg/mL. At a higher dose (100 μg/mL), LysGH15 also showed notable disrupting activity against 24-h and 72-h biofilms formed by S. aureus and coagulase-negative species. In the in vivo experiments, a single intraperitoneal injection of LysGH15 (20 μg/mouse) administered 1 h after the injection of S. epidermidis at double the minimum lethal dose was sufficient to protect the mice. The S. epidermidis cell counts were 4 log units lower in the blood and 3 log units lower in the organs of mice 24 h after treatment with LysGH15 than in the untreated control mice. LysGH15 reduced cytokine levels in the blood and improved pathological changes in the organs. The broad anti-staphylococcal activity exerted by LysGH15 on planktonic cells and biofilms makes LysGH15 a valuable treatment option for biofilm-related or non-biofilm-related staphylococcal infections.IMPORTANCEMost staphylococcal species are the maj...

Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Zhang Y, Cheng M, Zhang H, Dai J, Guo Z, Li X, Ji Y, Cai R, Xi H, Wang X, Xue Y, Sun C, Feng X, Lei L, Han W, Gu J Tags: Appl Environ Microbiol Source Type: research