Antimicrobial susceptibility of major pathogens of orofacial odontogenic infections to 11 β‐lactam antibiotics

In this study, we evaluated the current effectiveness of 11 β‐lactam antibiotics for treatment of orofacial odontogenic infections by determining the antimicrobial susceptibility of the major pathogens. The antimicrobial susceptibilities of viridans streptococci (n = 47), Peptostreptococcus (n = 67), Porphyromonas (n = 18), Fusobacterium (n = 57), black‐pigmented Prevotella (n = 59) and non‐pigmented Prevotella (n = 47) isolated from pus specimens of 93 orofacial odontogenic infections to penicillin G, cefmetazole, flomoxef, cefoperazone, cefoperazone/sulbactam, ceftazidime, cefpirome, cefepime, cefoselis, imipenem and faropenem were determined using the agar dilution method. Penicillin G, most cephalosporins, imipenem and faropenem worked well against viridans streptococci, Peptostreptococcus, Porphyromonas and Fusobacterium. Penicillin G and most cephalosporins, including fourth‐generation agents, were not effective against β‐lactamase‐positive Prevotella, though they were effective against β‐lactamase‐negative strains. Cefmetazole, cefoperazone/sulbactam, imipenem and faropenem expressed powerful antimicrobial activity against β‐lactamase‐positive Prevotella. In conclusion, penicillins have the potential to be first‐line agents in the treatment of orofacial odontogenic infections. Most of the other β‐lactam antibiotics, including fourth‐generation cephalosporins, were not found to have greater effectiveness than penicillins. In contrast, cefmetazole, cefoperazone/sulbactam, imipenem and faropenem were found to have greater effectiveness than penicillins.