Identification, Cloning, and Characterization of Staphylococcus pseudintermedius Coagulase

Area of Science:

• Microbiology
• Immunology
• Biochemistry

Background:

• Coagulase activity in Staphylococcus species promotes infection by inducing fibrin deposition.
• Staphylococcus pseudintermedius possesses coagulase activity, but the specific gene and protein remain uncharacterized.
• Understanding coagulase function is crucial for developing strategies against Staphylococcus infections.

Purpose of the Study:

• To characterize the coagulase protein from Staphylococcus pseudintermedius.
• To investigate the prothrombin activation capabilities of the S. pseudintermedius coagulase.
• To explore the interactions of the coagulase with host immune components.

Main Methods:

• Cloning and expression of a putative coagulase gene from S. pseudintermedius.
• Purification of the recombinant S. pseudintermedius coagulase protein.
• Assessing prothrombin activation using a chromogenic substrate assay.
• Evaluating binding affinities to human and bovine prothrombin, complement C3, and immunoglobulin.
• Testing the effect of recombinant coagulase on S. pseudintermedius phagocytosis.

Main Results:

• A recombinant protein with 40% similarity to S. aureus coagulase was produced.
• The S. pseudintermedius coagulase demonstrated prothrombin activation activity.
• The protein exhibited stronger binding to bovine prothrombin than human prothrombin.
• Binding to complement C3 and immunoglobulin was observed.
• Recombinant coagulase facilitated bacterial escape from phagocytosis.

Conclusions:

• The characterized S. pseudintermedius coagulase protein possesses multifunctional properties.
• These properties, including prothrombin activation and immune molecule binding, contribute to bacterial immune evasion.
• The coagulase likely plays a significant role in the virulence of S. pseudintermedius infections.