PERIAPICAL ABSCESSES - CAUSAL BACTERIA AND ANTIBIOTIC-SENSITIVITY

The purpose of this study was to investigate the aerobic and anaerobic flora of periapical abscesses and evaluate their susceptibility to va rious antibiotics. In 52 patients, with a diagnosis of periapical absc esses,, pus cultures were taken. Forty-two aerobes and 122 anaerobes w ere revealed, with 2 or more than 2 anaerobic strains isolated in 36 p atients. Infections were purely aerobic in 6%, purely anaerobic in 17% and mixed in 75%, while in 2% of the specimens there was no growth of microorganisms, Among anaerobes, microorganisms from the Bacteroides group (38.5%), Peptostreptococcus spp. (24.6%), Peptococcus spp. (13.9 %), and Fusobacterium spp. (4.1%), predominated in all cultures. Among aerobes the most prevalent bacteria were streptococci (47.6%) followe d by staphylococci (35.6%) while Enterobacteriaceae were isolated in 4 .8% of specimens. Selected susceptibility tests performed on several a naerobic species revealed that nitroimidazole derivatives, chloramphen icol and clindamycin retain their broad spectrum killing activity agai nst anaerobes, followed by cefoxitin and moxalactam. Of the newer quin olones, ofloxacin was the most effective. It is evident that the high isolation rate of anaerobic bacteria should influence empiric therapeu tic decisions.