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.

Effects of Enrofloxacin on Porcine Phagocytic Function

“…Similar observations were made for ciprofloxacin in mouse and human phagocytes (10,11). A much higher value was reported for sparfloxacin by using guinea pig peritoneal macrophages (8). As was observed with other quinolones (8,12,13,(27)(28)(29), we also found that 80 to 90% of the intracellular enrofloxacin was released from phagocytes within 10 min when the phagocytes were placed in enrofloxacin-free medium.…”

“…In the latter case, phagocytosis by AMs and PMNs was independent of the serum concentration. Under all variations of serum concentration and particle type, no significant differences in phagocytosis by PMNs or AMs were observed in the presence or absence of enrofloxacin (P Ͼ 0.570), as was described by others (8,12,23) for other quinolones. As is evident from Fig.…”

Influence of Moxifloxacin, Comparator Drugs and Some Fractions of Pulmonary Surfactant on Adherence of Some Respiratory Pathogens

“…In fact, surfactant phospholipids have been shown to exert suppressive effects on immune cell functions including cytokine release, lymphocyte proliferation, immunoglobulin production and natural killer cell cytotoxicity [4,5,7].A limited number of investigators have examined the effect of subinhibitory concentrations of antibiotics on the adherence of respiratory pathogens to epithelial cells [9,12,13,15,19]. Moreover, there are only few reports on the influence of pulmonary surfactant on antibiotic activity [20][21][22].…”

“…Pulmonary surfactant is a complex mixture of lipids (mainly phospholipids), proteins and carbohydrates which lines the alveolar surface of the lung and reduces the surface tension at the air-liquid interface [3,4]. Another wellcharacterized function of this complex is its involvement in the defense system of the lung, mainly attributable to surfactant protein-A (SP-A), a surfactant protein that, thanks to its opsonizing activity, favors nonspecific clearance of microorganisms by phagocytic cells [3][4][5][6][7].At subinhibitory concentrations, some antibiotics can prevent the formation of adhesins or affect their structure and functional properties, thus preventing the adherence of respiratory pathogens to the host cells [8][9][10][11][12][13][14][15].…”

Quinolone Antibacterials

“…By exposing a Staphylococcus aureus strain isolated from a bronchial aspirate to subinhibitory concentrations of sparftoxacin, DESNOTTES and DIALLO (1994) demonstrated that 1/2 and 1/4 of the MIC reduced the adherence by more than 50%; 1/8 and 1/16 of the MIC reduced it to 40% and 20%, respectively. No differences to the drug free controls were detectable at 1/32 of the MIC.…”