The search of vancomycin resistant enterococci in human oral cavities

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 11672028
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Osaka Dental University
• Principal Investigator: MURATA Yuichi Osaka Dental University, First Department of Oral and Maxillofacial Surgery Assistant, 歯学部, 助手 (90067116)
• Co-Investigator(Kenkyū-buntansha): ONOE Takatoshi Oaaka Dental University, Department of Bacteriology Lecturer, 歯学部, 講師 (90098012)
• Project Period (FY): 1999 – 2001
• Keywords: β-Lactam / Vancomycin / VRE / Normal oral microbial flora / enterococcus / Antibiotic resistance

Research Abstract

We studied the isolation frequency of vancomycin (VCM) resistant enterococci (VRE) in human oral cavities, and the antibacterial sensitivity of oral enterococci. The saliva was gathered from three groups ; group a : 42 subjects from 20 to 64 years old, group B : 125 subjects from 64 to 97 years old, and group C : 12 subjects treated with VCM. The saliva that diluted with 0.9% saline was spread on CS agar plates for enterococci and CS agar plates with 6 μg / ml VCM for VRE. The isolation frequency of enterococci fromsalica was 43% in group A, 39% in group B, and 58% in group C. However, VRE was not isolated from all saliva used. The 90% minimum inhibitory concentration (MIC_<90>) of piperacillin, cefaclor, cefazoline, cefmenoxim, cefmetazole, cefeteram and imipenem against 93 isolates of eculin-hydrolysisand catalase-negative-Gram-positive cocci (enterococi) was ≦2 μg / ml. The value of VCM was in a range of 0.032 to 1 μg / ml. That values of aztreonam and latamoxef were 8 and ≧128μg / ml, respectively. The MIC_<90> of ofloxiacin, minocycline, erythromycin, clindamycin and gentamicin was in a range of 0.16 ot 16μg / ml. Four β-lactam resistant enterococcalisolates, 3 macrolides resistant enterococcal isolates and 34 minocycline resistant enterococcal isolates were detected from human oral cavitles. β-Lactamase activity was not observed in β-lactam resistant enterococcal isolates by nitrocefin. Vancomycin resistant genes in enterococci with D-antigen were not detected with Van A, B and C PCR primers. Amplification by PCR with primers of Streptococcus pneumoniage penicillin binding protein genes was observed the PBP 1A and the PBP2 X from β-lactam resistant enterococcal isolates
These results suggest that enterococci originating from oral cavlties do not possess VCM resistant gene. But, it may be presumed that the β-lactam resistant enterococcal isolates keep the variataion of PBP gene