Treatment of aspiration pneumonia based on the antimicrobial susceptibility pattern of oral bacterial pathogens

Abstract

Aspiration pneumonia is a pulmonary disease caused by aspiration of mouth contents as a result of deglutition dysfunction, and the number of patients is, especially among the elder population, on the rise. As for the causative agents of aspiration pneumonia, based on the pathogenetic mechanism described above, oral surgery-related bacterial pathogens, especially anaerobes, are believed to be the major etiologic agents. In this study, we evaluated the antimicrobial susceptibility pattern of the major causative oral surgery-related bacterial pathogens-Streptococcus anginosus group, Peptostreptococcus species, Prevotella species and Fusobacterium species-against antimicrobial agents-piperacillin, tazobactam/piperacillin (TAZ/PIPC), ampicillin, sulbactam/ampicillin (SBT/ABPC), ceftriaxone, cefepime, meropenem (MEPM) and clindamycin. Of these antimicrobial agents, TAZ/PIPC and SBT/ABPC, penicillin antimicrobial agents containing a betalactamase inhibitor, and MEPM showed the highest antibacterial activity against all the four pathogens. These results suggest that penicillin antimicrobial agents containing a beta-lactamase inhibitor, such as TAZ/PIPC, are effective in treating aspiration pneumonia, which are mainly caused by oral anaerobic bacteria and often associated with oral surgery-related inflammation and odontogenic infections. In addition, these findings lend support to the selection of TAZ/PIPC as empiric therapy for the treatment of aspiration pneumonia in guidelines published overseas.