Desnottes J F, Diallo N, Loubeyre C
Rhône-Poulenc Santé, Institut de Biopharmacie, Antony.
Presse Med. 1989 Oct 11;18(32):1572-5.
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.
尿路感染的治疗是新型口服头孢菌素头孢克肟的适应证之一。本研究的目的是研究头孢克肟低于和低于最低抑菌浓度（MIC）时，对三种尿路致病性大肠杆菌菌株在生长阶段（37℃培养18小时）用低于MIC（MIC的1/2至1/64）的头孢克肟预处理后的形态、血凝和对上皮细胞黏附性的体外影响。这种处理导致细菌出现丝状形成的形态改变。大肠杆菌菌株表现出不同的血凝谱（MS；MS-MR；MR）。在存在低于MIC的头孢克肟（MIC的1/2至1/32）时，MR型大肠杆菌的血凝能力（使用豚鼠、人P1和p红细胞）明显改变。用人类颊细胞研究MS黏附素的黏附性，用人类尿道上皮细胞研究MR黏附素的黏附性。在用头孢克肟（最高至MIC的1/32）预处理大肠杆菌菌株后，观察到黏附性显著降低（70%-90%）。与其他对大肠杆菌有活性的抗生素如萘啶酸、诺氟沙星和氨苄西林相比，头孢克肟MIC的1/8对黏附性的影响更明显。这些结果表明，头孢克肟低于MIC时可显著降低大肠杆菌的黏附性。这一特性可能增强头孢克肟治疗大肠杆菌所致尿路感染的有效性。
