STUDIES IN AGGLUTINATION : II. THE RELATIONSHIP OF REDUCTION OF ELECTRICAL CHARGE TO SPECIFIC BACTERIAL AGGLUTINATION

Area of Science:

• Microbiology
• Immunology
• Biophysics

Background:

• The electrical charge on bacterial surfaces influences their interactions.
• Bacterial agglutination is a key immunological phenomenon.
• Previous research established a critical potential zone for bacterial agglutination.

Purpose of the Study:

• To investigate the effect of immune serum on the electrical charge of bacteria.
• To determine the relationship between serum properties and charge modification.
• To explore potential diagnostic applications of this interaction.

Main Methods:

• Studying the electrical charge of bacteria in the presence of immune serum.
• Quantifying the charge-reducing effect of immune agglutinating serum.
• Adsorbing agglutinin from serum using homologous and heterologous bacteria.
• Testing bacterial agglutination with various electrolytes, including sodium hydrogen phosphate (Na(2)HPO(4)) and phosphate buffer solutions.

Main Results:

• Immune agglutinating serum exhibits a specific charge-reducing effect directly proportional to its agglutination titer.
• This charge-reducing effect is lost upon removal of agglutinin by homologous bacteria but not by heterologous bacteria.
• A protective, non-agglutinating serum did not demonstrate this charge-reducing effect.
• Northrop and De Kruif's findings on the critical potential zone for agglutination were confirmed for most electrolytes.
• Specific bacterial agglutination occurred at higher negative charges with Na(2)HPO(4) or phosphate buffers, and even without observable charge reduction in high serum dilutions.

Conclusions:

• Immune agglutinating serum actively modifies bacterial surface charge.
• Bacterial agglutination is strongly linked to charge reduction, with specific exceptions under certain electrolyte conditions.
• The observed charge-reducing effect of immune serum may hold diagnostic value.