Natural Bactericidal Antibodies: Observations on the Bactericidal Mechanism of Normal Serum

Quantitative studies on the bactericidal actions of serum and complement. II. Some implications for the mechanism of the bactericidal reaction.

Serum bactericidal test.

The serum bactericidal test represents one of the few in vitro tests performed in the clinical microbiology laboratory that combines the interaction of the pathogen, the antimicrobial agent, and the patient. Although the use of such a test antedates the antimicrobial era, its performance, results, and interpretation have been subject to question and controversy. Much of the confusion concerning...

Potentiation of antibiotic bactericidal activity by normal human serum.

Combinations of certain antibiotics and normal human serum at concentrations at which there was no killing by the agents when used alone were found to be bactericidal for Escherichia coli K-12 cells. This effect was observed with tetracycline, streptomycin (SM), trimethoprim, and ampicillin, but not with chloramphenicol or nalidixic acid. Synergy between SM and human serum was also observed aga...

Performance of the Serum Bactericidal Test

Questionnaires were sent to 37 diagnostic microbiology laboratories to assess their methods for performance of the serum bactericidal test. Of the 28 responding laboratories, 26 utilized the test, with considerable variation among methods. Culture and dilution media included Trypticase soy, Mueller-Hinton, brain heart infusion, Columbia broth, dextrose phosphate, and pooled human serum. Several...

Serum bactericidal testing with the Autobac system.

Current methodology for the serum bactericidal test requires a minimum of 48 h. A procedure was devised for performing this test with the Autobac system (General Diagnostics, Div. Organon Inc., Raleigh, N.C.) in a shortened time span. All titers obtained with the Autobac were compared against results obtained with a standardized tube dilution procedure. The Autobac low-thymidine eugonic broth p...