Antibacterial interaction of cefuroxime and serum from uraemic patients

A strain of Proteus rettgeri was exposed to combinations of subinhibitory concentrations of cefuroxime and serum from normal subjects and from uraemic patients (on conservative and on haemodialysis treatment) and the antibacterial activity of these was determined. Cefuroxime and normal serum gave a synergistic effect. Compared with controls, the combination of cefuroxime and uraemic serum from patients on conservative treatment showed a reduced inhibitory effect. The antibacterial activity of the combination including serum from dialysis patients was similar to that with normal serum; however, this was due to the greater activity of serum from these patients than of serum from normal subjects, and no synergistic interaction with cefuroxime was demonstrated. An alteration of bacterial growth was observed in the presence of uraemic serum. No clearcut correlation was found between the serum concentrations of uraemic metabolites and the antibacterial activity of the combination.