555 Prevalence of MRSA in Dental Settings

Thursday, March 22, 2012: 3:30 p.m. - 4:45 p.m.
Presentation Type: Poster Session
S. SADEGHI1, A.E. ROSATO2, D.H. SHERVIN2, and D.M. LASKIN1, 1Oral and Maxillofacial Surgery, Virginia Commonwealth University - VCU/MCV, Richmond, VA, 2Infectious Disease, Virginia Commonwealth University - VCU/MCV, Richmond, VA
Objective: MRSA-related infections remain a major concern among healthcare providers. The purpose of this study was to investigate the presence of methicillin-resistant staphylococcus aureus (MRSA) in dental settings and among dental students at Virginia Commonwealth University School of Dentistry.

Method: Samples from 20 gloves and glove boxes and 10 computer keyboards and mouses were collected from dental operatories in the Departments of Oral and Maxillofacial Surgery and General Practice.  The samples from gloves and glove boxes were compared to sterilized surgical gloves as a control. Samples were also collected from randomly selected dental students’ hands before starting a procedure. After an incubation period, collected samples were treated with catalase, cultured on mannitol plates to identify Staph and finally subjected to antimicrobial susceptibility testing.

Result: : No specific MRSA were identified. However, the antibiotic sensitivity tests indicated resistance to beta lactamase among  samples in the following ratios: 1/20 from gloves only samples, 1/20 from glove + glove boxes, 4/10 from keyboard and mouses, 1/15 students’ hands indicating the possible presence of MRSA.

Conclusion: Additional techniques such as the test for the mecA gene are required to identify specific MRSA colonies. Therefore, the results of this clinical study remain unclear.  However, examination of collected samples under the microscope indicated the prevalence of many organisms including staph. epidermitis. These colonies were found on presumably clean surfaces. Therefore, washing hands thoroughly before starting a dental procedure and touching glove boxes still remains the most important factor in the prevention of cross-contamination and infection control in dental settings.

Keywords: Infection, MRSA, cross-contamination and Microbiology