Long-term periodical isolation of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) from Japanese children's oral cavities

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing nosocomial infections. To control nosocomial infection in a dental hospital, periodical surveillance of MRSA from the oral cavity is very important. Furthermore, this surveillance might reveal any alteration of the incidence of MRSA among healthy children in a particular area, because many children having no systemic disease except for dental problems come to dental offices.MethodsTotally 741 children were participated in the present study; 307 in 1987–88, 103 in 1992–93, 129 in 1997– 98 and 202 in 2002–2003. S. aureus was isolated from the tongues of children without systemic diseases. All isolates were investigated for coagulase types and susceptibilities to five antibiotics.ResultsS. aureus was isolated from 33–44% of children during the examination period. The incidence of MRSA was maximal in 1992–93, and then constant at around 3%. MRSA that have type II or III coagulase were relatively dominant.ConclusionAlthough outbreaks of MRSA in Japan was decreased in the early 90's, more than 3% of children without particular risks are considered positive for MRSA.