Molecular Typing of Clinical and Nasal Carriage Isolates of Staphylococcus Aureus by spa Gene Patterns

Background and purpose: Staphylococcus aureus is the most common cause of hospital and community acquired infections. Nasal carriage of S. aureus in staff provides a source for infection in hospitalized patients. The aim of this study was to evaluate the spa gene patterns of clinical and nasal carriage isolates of S. aureus using polymerase chain reaction. Materials and methods: Clinical specimens and staff nasal swab were collected from hospitals affiliated to Tehran University of Medical Sciences. S. aureus isolates were identified by cultural and biochemical methods. The evaluation of spa gene patterns of S. aureus isolates was carried out from staff nasal carriage and clinical specimens of patients using polymerase chain reaction. Results: A total of nine patterns of spa gene were distinguished. Seven and five different patterns were identified from S. aureus nasal carriage and clinical specimens, respectively. Conclusion: The presence of similar patterns from spa gene may indicate a common source of infection in the hospital wards. Analysis of these patterns may help in breaking the chain of transmission of infection in hospitals.