MULTIPLICITY OF THE GENES AND PLASMIDS CONFERRING RESISTANCE TO PRISTINAMYCIN IN STAPHYLOCOCCI SELECTED IN AN ALGERIAN HOSPITAL

In an Algerian hospital where pristinamycin (Pt) was extensively used for the treatment of chronic osteomyelitis and for prophylaxis in bone surgery, the prevalence of pristinamycin-resistant (Pt-R) staphylococ ci during a five-month period (20%) was higher than that among staphyl ococci isolated elsewhere in Algeria (4.5%). Analysis of 13 Pt-R staph ylococci isolated in this hospital revealed a diversity of plasmids an d genes conferring resistance to Pt and to related antibiotics. Most o f the Pt-R staphylococci were unrelated: they belonged to either diffe rent taxa or types. Nevertheless, some of the unrelated staphylococci harboured structurally related plasmids carrying streptogramin resista nce genes. Thus, these plasmids may have contributed to the dispersion of these genes.