Genetic Characteristics of Staphylococci and Prevalence of CA-MRSA Isolated from Oral Cavity

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K10450
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57080:Social dentistry-related
• Research Institution: Health Sciences University of Hokkaido
• Principal Investigator: HIROSE Mina 北海道医療大学, 歯学部, 准教授 (10265077)
• Co-Investigator(Kenkyū-buntansha): 八幡 祥子 北海道医療大学, 歯学部, 講師 (10285538) ; 福田 敦史 北海道医療大学, 歯学部, 助教 (10453276) ; 村田 幸枝 北海道医療大学, 歯学部, 講師 (90455676)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: CA-MRSA / 口腔 / 歯性感染症 / S.argenteus / コアグラーゼ陰性ブドウ球菌 / ブドウ球菌 / 唾液 / 小児

Outline of Final Research Achievements

The study was conducted to investigate the prevalence, antimicrobial resistance and genetic characteristics of Staphylococcus isolates from the oral cavity and skin (hand) of systemically healthy subjects with dental disease and dental staff as well as university’s students from 2019/12 to 2021/12.
Among a total of 629 subjects (213 patients, 68 staff, 330 students), the MRSA detection rate from oral cavity was 1.43%, and that from hand was 0.32%, respectively. ST8-SCCmec-IVl（CA-MRSA/J）, a new community-acquired MRSA, was detected 1 case, and ST6562(CC8)-SCCmec-IVa, which has the genetic characteristics of USA300, was detected in 2 cases from oral cavity. In addition, ST1-SCCmec-IVa, which has the genetic characteristics of USA400, was detected in one case from hand.　These findings indicated the potential distribution of USA300 clone-like MRSA in the oral cavity of dental patients and even though systemically healthy subjects.

Free Research Field

小児歯科学分野

Academic Significance and Societal Importance of the Research Achievements

市中感染型メチシリン耐性黄色ブドウ球菌 (CA-MRSA)は、各国で広がりを見せている。最近、日本特有の新規CA-MRSAが検出されたが、歯科領域の検体からの報告は皆無であるため、歯性感染症および健康人の口腔から分離される新規CA-MRSAの検出状況と分子疫学的・遺伝的特徴（遺伝子型、各種毒素・耐性遺伝子の保有）を解析し、感染（種類、重症度）との関係を明らかにする。また、菌間で遺伝子の移動が推測されるMRSA以外のブドウ球菌も解析し、現時点における口腔領域のブドウ球菌の伝播動態を解明する。本成果は、口腔領域のCA-MRSAの起源と伝播動態を探究することでその感染予防対策に資すると考えられる。