In-vitro comparison of the post-antibiotic effect of vancomycin and teicoplanin

The post-antibiotic effect (PAE) of teicoplanin was compared with that of vancomycin for five selected Gram-positive cocci. Two concentrations of each antibiotic were investigated, with the test organisms being exposed to each for both 1 and 2 h. At a concentration of 25 mg/l, teicoplanin had a greater PAE than vancomycin for the methicillin resistant staphylococci and Enterococcus faecalis strains tested. At a concentration of 5 mg/l, teicoplanin gave equal effects to those of vancomycin except for the strain of methicillin-resistant Staphylococcus aureus (MRSA) tested. The variation in the antibiotic exposure time gave only small changes in the PAE, except for the MRSA tested.