text: [Methicillin resistant clinical strains of Staphylococcus aureus isolated from patients in the State Clinical Hospital Nr 2 in Szczecin].
  Over a fivefold increase, from 11% to 58%, in the prevalence of methicillin-resistance was observed in 1994-95 amongst clinical isolates of Staphylococcus aureus in the State Clinical Hospital No 2 in Szczecin, one of the largest hospitals in the West Pomeranian region of Poland. The aim of this study was to see if any one particular strain was responsible for this apparent outbreak. Fifty-six randomly selected isolates were typed by SmaI macrorestriction analysis using PFGE and by analysis of antimicrobial susceptibility patterns. Results indicate the presence of two epidemic multi-drug resistant MRSA strains. Over 85% of typed MRSA belonged to the first strain, which was probably present in the hospital long before 1994. MRSA of this strain were isolated from patients in 8 hospital wards. The second strain was introduced into two wards of the hospital in the last year of the study.