Antimicrobial susceptibility surveillance of bacterial isolates recovered in Japan from odontogenic infections in 2018

Background

This study reports the findings of the second antimicrobial susceptibility surveillance study of isolates recovered from odontogenic infections in Japan.

Methods

A total of 164 odontogenic infections samples including periodontitis (group 1, n = 33), pericoronitis (group 2, n = 7), jaw inflammation (group 3, n = 83), and phlegmon in the jawbone area (group 4, n = 42) from 21 facilities were included in the study.

Results

Antimicrobial susceptibility testing was performed on 515 isolates, consisting of 120, 115, 173, 38, and 69 Streptococcus spp., anaerobic gram-positive cocci, Prevotella spp., Porphyromonas spp., and Fusobacterium spp. isolates, respectively. The ratio of susceptible bacteria to causative agents of odontogenic infections was determined in accordance with the guidelines of the Clinical and Laboratory Standards Institute. The susceptibility rates of Streptococcus anginosus were as follows: ampicillin, 98.6 %; cefcapene, ceftriaxone, meropenem, and doripenem, 100 %; clarithromycin and azithromycin, 71.2 %; and clindamycin, 87.7 %. The MIC90 value for ampicillin for Prevotella spp. was 32 μg/mL, with a susceptibility rate of 65.3 %. The MIC90 value for sulbactam/ampicillin was 2 μg/mL, with a susceptibility rate of 100 %.

Conclusions

The findings of the present study indicate that the resistance to the combination of penicillins and β-lactamase inhibitors, the first-line antimicrobial agents for odontogenic infections and oral infections caused by anaerobic flora, are low.