[Bacteriostatic and bactericidal effect of penicillins, cephalosporins, aminoglycosides and ampicillin plus gentamicin compared to trimethoprim plus sulfamethoxazole on "Listeria monocytogenes" (author's transl)]

Abstract

The bacteriostatic effect of penicillins and old and new cephalosporins was studied on ten strains of Listeria monocytogenes. Their bactericidal effects were studied in relation to time and concentration of antibiotics. If the betalactamines are bactericidal after 48 h only, they can be distinguished by their MBC/MIC ratio. Cephalosporins have a smaller ratio (8 to 32/200) than penicillin and ampicillin; the new cephalosporins have not improved the bactericidal effect of the oldest. The association trimethoprim plus sulfamethoxazole was equivalent to ampicillin plus gentamicin.