A lysozyme isolated from rainbow trout acts on mastitis pathogens.

Area of Science:

• Biochemistry
• Microbiology
• Veterinary Science

Background:

• Clinical mastitis is a significant concern in dairy farming, often caused by bacterial infections.
• Lysozymes are enzymes with known antimicrobial properties, but their efficacy against mastitis pathogens varies.
• Rainbow trout kidney lysozymes (type I and II) have not been extensively studied for their potential in combating mastitis.

Purpose of the Study:

• To evaluate the antibacterial activity of two purified rainbow trout kidney lysozymes (type I and II) against common mastitis-causing bacteria.
• To compare the efficacy of trout lysozymes with other known lytic agents, including hen egg-white lysozyme, lysostaphin, and mutanolysin.

Main Methods:

• Two types of lysozymes were purified from rainbow trout kidney.
• Antibacterial assays were performed on eight bacterial strains isolated from clinical mastitis cases (staphylococci, streptococci, coliforms).
• Bacteria were incubated with lysozymes in broth and milk, with colony-forming units (CFUs) enumerated to assess bacterial viability.

Main Results:

• Type II rainbow trout lysozyme demonstrated significant antibacterial effects against all tested bacterial strains.
• Type II lysozyme exhibited the highest efficacy against staphylococci.
• Type I rainbow trout lysozyme and hen egg-white lysozyme showed minimal antibacterial activity.

Conclusions:

• Type II lysozyme from rainbow trout kidney possesses potent antibacterial properties relevant to clinical mastitis.
• This specific lysozyme shows particular promise for targeting staphylococcal infections, a common cause of mastitis.
• Further research into rainbow trout lysozymes could lead to novel therapeutic strategies for bovine mastitis.