SUBSPECIES DISCRIMINATION OF STAPHYLOCOCCI FROM REVISION ARTHROPLASTIES BY RIBOTYPING

Sixty-six cultures of Staphylococcus spp. were obtained from bone and tissue samples collected from 37 patients during revision arthroplasti es and were speciated and ribotyped to assess strain diversity in each species. There were 10 ribotypes among 51 isolates of S. epidermidis, three among three isolates of S. capitis, two among four isolates of S. aureus and two among two isolates of S. simulans. One ribotype was found among each of: two isolates of S. warneri; two isolates of S. ha emolyticus and single isolates of S. cohnii and S. saprophyticus. Low molecular weight bands of ribotype patterns characterized one or two r elated species whereas high molecular weight bands were useful for dis tinguishing types within species. Specimens from 17 patients yielded m ore than one isolate of Staphylococcus spp. In 13 of these patients th e isolates were representatives of a single species but in only eight did ribotyping show the isolates to be identical. The findings of mult iple species and ribotypes from samples taken from the same patient ma y have implications for understanding the nature of infection in revis ion arthroplasty and for antibiotic therapy.