RESUMEN
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 (PtR) staphylococci during a five-month period (20%) was higher than that among staphylococci isolated elsewhere in Algeria (4.5%). Analysis of 13 PtR staphylococci isolated in this hospital revealed a diversity of plasmids and genes conferring resistance to Pt and to related antibiotics. Most of the PtR staphylococci were unrelated: they belonged to either different taxa or types. Nevertheless, some of the unrelated staphylococci harboured structurally related plasmids carrying streptogramin resistance genes. Thus, these plasmids may have contributed to the dispersion of these genes.
Asunto(s)
Antibacterianos/uso terapéutico , Plásmidos/genética , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus/genética , Virginiamicina/uso terapéutico , Argelia/epidemiología , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Tipificación de Bacteriófagos , Huesos/cirugía , Infección Hospitalaria , Cartilla de ADN/genética , ADN Bacteriano/análisis , ADN Bacteriano/genética , Brotes de Enfermedades , Farmacorresistencia Microbiana/genética , Genes Bacterianos , Humanos , Pruebas de Sensibilidad Microbiana , Hibridación de Ácido Nucleico , Osteomielitis/tratamiento farmacológico , Reacción en Cadena de la Polimerasa , Prevalencia , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/genética , Staphylococcus/efectos de los fármacos , Staphylococcus/patogenicidad , Virginiamicina/administración & dosificaciónRESUMEN
Oral administration of strontium to calcium wellfed rats blocks the intestinal absorption of calcium. When high doses of vitamine D are given over long period, the inhibition of calcium intestinal absorption disapears. Under these conditions the absorption of strontium is increased. It is suggested that there is only one absorption mechanism for these two cations. An overdose of the vitamine D increases the renal elimination of strontium but under these conditions the plasma concentration of the strontium is unchanged. Vitamine D brings about the some action on the bone fixation of the strontium as it does on the bone fixation of calcium. The bone fixation is increased with low dosages. The bone fixation is decreased with high dosages.