Effective Antimicrobial Activity of Plectasin-Derived Antimicrobial Peptides against Infection in Mammary Glands.

() is the causative agent for a wide variety of illnesses ranging from minor skin infections to life-threatening diseases. Development of antibiotic resistance by the bacteria has rendered many antibiotics ineffective. It has been known that plectasin-derived antimicrobial peptides (AMPs; NZ2114 and MP1102) are promising alternatives to antibiotics. However, their activities against in mammary glands were unknown. Our objective was to assess the antimicrobial activities of NZ2114 and MP1102 against in milk, in cultured mammary epithelial cells, and in a mouse model in order to evaluate their potentials as anti-mastitis agents. NZ2114 and MP1102 showed bactericidal effects against in both the culture medium and the milk. NZ2114 and MP1102 at the concentration of 100 μg/mL reduced the number of by almost 100% within 4 h in processed bovine milk. Similarly, both NZ2114 and MP1102 were efficient to reduce the number of internalized in cultured mammary epithelial cells. Finally, both AMPs significantly reduced the load and concentrations of TNF-α and IL-6 in mammary glands, compared to a buffer control in the mouse model. Our results suggest that NZ2114 and MP1102 may be used to treat -induced mastitis.