Antibiotics and granulocytes. Direct and indirect effects on granulocyte chemotaxis.

Twelve antibiotics were investigated regarding both their direct in vitro influence on granulocyte chemotaxis, and their indirect effect on the production of chemotactic factors from cultures of Escherichia coli and Pseudomonas aeruginosa. None of the beta-lactam antibiotics studied caused significant alterations of granulocyte migratory response when incubated with the cells at concentrations of up to 128 microgram/ml. The two aminoglycoside preparations, and the two tetracycline preparations caused significant depressions of the migration response. Production of chemotactic factors was stimulated from growing cultures of E. coli by sub-minimal inhibitory concentrations of beta-lactam antibiotics and from Ps. aeruginosa by the cephalosporin derivatives only. The differences observed were most probably due to the mode of action at the bacterial cell wall level.