[Effect of sub-inhibitory concentrations of cefixime on the morphology, hemagglutination and adhesiveness of urinary strains of Escherichia coli].
The treatment of urinary tract infections is one of the indications of cefixime, a new oral cephem. The aim of the present work was to study the in vitro effect of cefixime sub- and infra-MICs on the morphology, haemagglutination and adhesiveness to epithelial cells of three uropathogenic Escherichia coli strains pretreated with sub-MICs (1/2 to 1/64 the MIC) of cefixime during growth phase (37 degrees C for 18 h). This treatment led to morphological alterations of the bacteria with filament formation. The E. coli strains showed different haemagglutination profiles (MS; MS-MR; MR). In the presence of cefixime sub-MICs (1/2 to 1/32 the MIC), MR E. coli showed a markedly altered capacity for haemagglutination (using guinea pig, human P1 and p erythrocytes). Adhesiveness was studied with human buccal cells for MS adhesins and human urothelial cells for MR adhesins. A significant decrease of adherence (70-90 per cent) was observed after pretreatment of E. coli strains with cefixime (up to 1/32 the MIC). Compared with other antibiotics active against E. coli, such as nalidixic acid, norfloxacin and ampicillin, the effect of 1/8 the MIC of cefixime on adhesiveness, was more pronounced. These results demonstrate that sub-MICs of cefixime induce a marked reduction in adhesiveness of E. coli. This property might potentiate the effectiveness of cefixime in the treatment of urinary tract infections due to E. coli.
Desnottes
J F
JF
Rhône-Poulenc Santé, Institut de Biopharmacie, Antony.
Diallo
N
N
Loubeyre
C
C
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D020682:Cefixime; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000648:ultrastructure; D006168:Guinea Pigs; D006384:Hemagglutination / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning
D000900:Anti-Bacterial Agents; D020682:Cefixime; D002439:Cefotaxime
Action de concentrations sub-inhibitrices de céfixime sur la morphologie, le pouvoir hémagglutinant et d'adhésion de souches urinaires d'Escherichia coli.