Studies on antistreptolysin O activity generated in serum by microorganisms

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Normal human serum contains factors that can be activated by bacterial growth.
• Staphylococcus aureus and Pseudomonas aeruginosa can induce the generation of an antistreptolysin factor (ASF).

Purpose of the Study:

• To investigate the generation and characteristics of antistreptolysin factor (ASF) in human serum.
• To understand the role of bacterial products and serum components in ASF activity.

Main Methods:

• Bacterial cultures (Staphylococcus aureus, Pseudomonas aeruginosa) were used to stimulate normal human serum.
• Cholesterol esterase activity was assessed in DEAE-cellulose column fractions.
• Beta-lipoprotein alterations were analyzed using gel electrophoresis.
• Dextran sulphate precipitation was employed to isolate and study beta-lipoproteins.

Main Results:

• ASF was generated in serum upon growth of S. aureus and P. aeruginosa, particularly by alpha-toxin producing strains.
• Cholesterol esterase, produced by positive strains, was linked to ASF activity.
• ASF development was slow, peaking between days 5-10, and correlated with changes in beta-lipoproteins.
• An esterase inhibitor in some sera and a staphylococcal binding fraction influenced ASF activity.

Conclusions:

• Antistreptolysin factor (ASF) is a component of normal human serum, inducible by bacterial growth.
• ASF appears to be a non-specific defense mechanism capable of binding bacterial products.
• Serum esterase inhibitors and bacterial-derived fractions modulate ASF activity.