Amoxicillin-resistant oral streptococci identified in dental plaque specimens from healthy Japanese adults

作者：Masuda Katsuhiko; Nennoto Hirotoshi; Nakano Kazuhiko^*; Naka Shuhei; Nomura Ryota; Ooshima Takashi

来源：Journal of Cardiology, 2012, 59(3): 285-290.

DOI：10.1016/j.jjcc.2011.12.004

• Endocarditis
• Infectious disease
• Patient care
• Prevention
• Risk factors

Background: Infective endocarditis (IE) is known to be a life-threatening disease and invasive dental procedures are considered to be important factors. Oral amoxicillin (AMPC) is widely used for prophylaxis in patients with heart disorders who are at risk for IE. However, there is only limited information regarding the inhibition of oral bacteria by AMPC.
Methods and results: Dental plaque specimens were obtained from 120 healthy Japanese adult subjects, then diluted and streaked onto selective medium for oral streptococci. The minimum inhibitory concentration (MIC) of AMPC was evaluated using a macro-dilution method by Clinical Laboratory Standard Institute (2006). Seven strains with an MIC of AMPC of 16 mu g/mL or more were isolated from 5 subjects. The bacterial species were confirmed by sequence analysis of 165 rRNA from each strain, which demonstrated that most were Streptococcus sanguinis, followed by Streptococcus oralis. Dental plaque specimens collected from these 5 subjects again after an interval of 2-3 months possessed no strains with an MIC of AMPC of 16 mu g/mL or more.
Conclusions: These findings suggest that strains with a high MIC of AMPC are present in the oral cavities of Japanese adults, though they may be transient rather than inhabitants.

• 出版日期2012-5