RESUMEN
BACKGROUND: This study was designed to investigate the isolation rate of Staphylococcus aureus from hands and nasal cavities of physicians and nurses and to determine the relationship between the isolates of S. aureus from patients with nosocomial infection and the isolates from physicians, nurses and the hospital environment. METHODS: Twenty-three S. aureus isolates which consisted of 8 strains from patients, 7 strains from doctors and nurses, 7 strains from hospital environments, and S. aureus ATCC 25923 were examined. Biochemical profile by the use of API Staph (API system, La Balme-Les Grottes, France), antibiogram by disk diffusion method, and random amplified polymorphic DNA analysis (RAPD) were used for the strain differentiation and molecular typing of S. aureus isolates. RESULTS: The isolation rate of S. aureus in hands and nasal cavities of doctors and nurses was 21% (25/ 120) and 28% (33/120), respectively. The isolation frequency of methicillin-resistant S. aureus (MRSA) from doctors, nurses, and hospital environments was 57% (8/ 14). The isolates disclosed 13 different biochemical profiles and 14 different resistant patterns of antimicrobials. All isolates were divided into five molecular types (A~E) by RAPD with a similarity (S) value of 0.55; 10 strains (45%) belonged to type A, 7 (32%) to type C, 3 (14%) to type B, one each to type D and E, respectively. The S value between strain 11 from hospital environments and strain 12 from a patient was 1.00, which means that they are the same on the genetic level. CONCLUSION: These findings reveal the existence of a close relationship between clinical isolates and isolates from hospital environment, including those from physicians and nurses. Thus, the implementation of an infection control programs to reduce the spread of MRSA within hospitals is important for the prevention of nosocomial infections.