title: Effect of sparfloxacin on Staphylococcus aureus adhesiveness and phagocytosis.
abstract: We investigated the effect of sparfloxacin, a new broad-spectrum fluoroquinolone, on the morphology, adhesiveness and phagocytosis of a clinical isolate of Staphylococcus aureus sensitive to this compound (MIC = 0.06 mg/L). The strain was tested for its adherence to human buccal epithelial cells, measured by interference contrast microscopy, and for phagocytosis by guinea-pig peritoneal macrophages, measured by fluorescence microscopy. Accumulation of sparfloxacin by macrophages was studied by means of a velocity-gradient centrifugation technique. The S. aureus strain, grown in the presence of sub-inhibitory concentrations of sparfloxacin, exhibited an increased cell diameter and a markedly reduced capacity to adhere to buccal epithelial cells. The phagocytic capacity and activity of macrophages were greater with the treated strain than with an untreated control. A reduction in numbers of intracellular cocci was also observed 2 h after postphagocytic treatment of macrophages with sparfloxacin at 10 x MIC. This intracellular bactericidal activity may result from accumulation of sparfloxacin in macrophages, evidenced by a high ratio of cellular to extracellular concentration. It was concluded that sparfloxacin reduces adherence to epithelial cells, increases phagocytosis and facilitates the intracellular killing of S. aureus.
authors.affiliation: Rhône-Poulenc Rorer S.A., Centre de Recherche de Vitry-Alfortville, Département de Biologie, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Desnottes
authors.forename: N
authors.initials: N
authors.lastname: Diallo
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D024841:Fluoroquinolones; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects*; D015363:Quinolones / Q000493:pharmacokinetics / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; C061363:sparfloxacin