[Microcalorimetric Investigations, regarding the antibacterial efficiency of chemotherapeutics (author's transl)].

An investigation method is described by which microcalorimetry and continuous density measurement are used to show the antibacterial efficiency of chemotherapeutics. Oleandomycin, erythromycin, both macrolide antibiotics, and doxycycline, a tetracycline, blockers of the protein synthesis, have the same effect on the microcalorimetric curve of a staphylococcus strain. Among the aminoglycosides tobramycin and gentamicin influenced the microcalorimetric activity of a growing E. coli strain in the same way, spectinomycin produced different curves. Penicillins interfere with the synthesis of the cell membrane by blocking the enzyme transpeptidase. Epicillin, penicillin, ampicillin, oxacillin, carbenicillin, and azlocillin influence the microcalorimetric activity of staphylococci in a typical way which is different from that of the blockers of the protein synthesis.