IN-VITRO ANTIMICROBIAL SUSCEPTIBILITY OF PORPHYROMONAS-GINGIVALIS TO AZITHROMYCIN, A NOVEL MACROLIDE

The in vitro antimicrobial susceptibility of Porphyromonas gingivalis to azithromycin, a new macrolide antibiotic of a new class known as az alides, was investigated by the agar dilution method on Brucella agar. Eighty-two P gingivalis strains, 79 recent oral isolates, 1 nonoral i solate and 2 reference strains were included in the study. Azithromyci n was highly effective against P gingivalis. All strains were inhibite d at 1.0 mug/ml of azithromycin or less, The minimal inhibitory concen trations were 0.25 mug/ml for 50% and 0.5 mug/ml for 90%. These in vit ro data as well as the favorable pharmacokinetics of azithromycin indi cate that this new oral macrolide might be a good candidate for future clinical trials aiming to eradicate P gingivalis from refractory peri odontitis.