Detection of Infection Pattern in Dental Clinic

Objectives: To investigate the cross contamination in dental clinic, Staphylococcus aureus(S. aureus), the pathogen in acute pyogenic infection and one of the important microbes causing nosocomial infection, was isolated from the mouth and anterior nare of healthy personnel and patients and the air in dental clinic. Methods: The isolation rate of S. aureus and methicillin resistant S. aureus(MRSA) was investigated. The patterns of antibiotic susceptibility of the isolated staphylococci were examined, and mecA gene from the microbe of MRSA and methicillin resistant coagulase negative staphylococci(MRCNS) was detected by polymerase chain reaction(PCR). Results: 108 strains of S. aureus were isolated and 20 strains of them were identified as MRSA. The isolation rate of S. aureus was the highest in the mouth of dentists(29.4%) and the lowest in the air of dental clinic(1.3%). In the study of PCR, MRSA, MRCNS and some methicillin susceptible staphylococci had mecA positive gene. The nucleotide sequence of PCR products showed high homology with S. aureus mecA(93.0%) and femA(99.0%), and the deduced amino acid sequence was identical to the methicillin resistant mecA subunit of S. aureus. Conclusions: These results suggest that staphylococci in a dental environment may be one of the important causes of nosocomial infection in dental clinic.