[Relation of the chelating property of nitroxoline, the surface hydrophobicity and the inhibition of bacterial adherence]. / Relations entre les propriétés de chélation de la nitroxoline, l'hydrophobicite de surface et l'inhibition de l'adhérence bactérienne.

Nitroxoline or 5-nitro-8-hydroxyquinoline acts by a chelating effect with various metallic divalent cations. The chelating property of nitroxoline has been proposed as an hypothesis to explain the activity of this drug, at sub-MIC, on the inhibition of bacterial adherence. Nitroxoline (MIC/4) does not inhibit fimbriae synthesis but its antibacterial activity on E. coli 387 (MS/MS) was decreased by the addition of MgCl2 (50 mM) and CaCl2 (10 mM). The chelating effect of nitroxoline is mainly due to the presence of the nitrous radical in position 5. Nitroxoline would act at the outer membrane level of the bacterial cell-wall by a chelating effect preferentially with Mg++ than Ca++. Furthermore, nitroxoline (MIC/8) increases the bacterial surface hydrophobicity of E. coli 38 in contrast to EDTA (MIC/4). The both products inhibit the bacterial adherence to cells with the same manner.

[Inhibition of bacterial adherence by nitroxoline on cellular adhesion and on urinary catheter surfaces]. / Inhibition de l'adhérence bactérienne par la nitroxoline sur support cellulaire et sur sonde urinaire.

Nitroxolin or 5-nitro-8-hydroxyquinoline, used in the treatment of acute or recurrent uncomplicated urinary tract infection (UTI), has been investigated to demonstrate inhibitory effect on bacterial adherence to epithelial cells or solid surfaces. Nitroxolin in vitro and in urine inhibits bacterial adherence of E. coli 38 (MS/MS) on HeLa cells and epithelial cells from human bladder mucosa. In the same conditions, norfloxacin has no effect. Nitroxolin (MIC/8) decreases with a statistically significant difference (p less than 0.001) the bacterial attachment to a urinary catheter surface made in siliconated latex. These results justify the performance of a clinical trial in the prophylaxis of recurrent UTI and the outcome of a bacteriuria associated with indwelling or intermittent bladder catheter.

[Inhibition of bacterial adhesion of uropathogenic Escherichia coli strains by the urine of patients treated with nitroxoline]. / Inhibition de l'adhésion bactérienne de souches d'Escherichia coli uropathogènes par des urines de patients traités par la nitroxoline.

The present study evaluates the effects of sub-inhibitory concentrations of nitroxoline, (oxyquinoline derivative) widely used in the treatment of uncomplicated, urinary tract infections, on the adherence of uropathogenic strains of Escherichia coli. These bacterial strains showed mannose sensitive and/or mannose resistant hemagglutinating activity (HA). In the presence of nitroxoline and at sub-MIC concentrations, inhibition of adherence is 90% (MIC/4), 87% (MIC/8), and 70% (MIC/16), whatever HA's are expressed by the E. coli strains. The inhibitory effect on adherence is also observed in the urine after oral administration of 400 mg of nitroxoline. The concentrations of nitroxoline in the urine are determined by microbiological assay (anti-bacterial activity) and by physico-chemical assay (total nitroxoline and free nitroxoline). The percentages of inhibition are related to the concentrations of free and conjugated nitroxoline. For a 1/16 dilution of urine, the inhibitory effect is 70% and 87% respectively 1 h 30 and 2 h 30 after oral administration of nitroxoline. After 5 h, a similar inhibitory effect is observed for a 1/2 dilution of urine. These results justify the performance of a clinical trial on the prophylaxis of recurrent urinary tract infections by nitroxoline.

[In vitro antifungal activity of nitroxoline. Preliminary clinical results]. / Activité antifongique de la nitroxoline in vitro. Résultats cliniques préliminaires.

Nitroxoline is an oxyquinoline derivative with a large antifungical activity. The fungistatic activity of nitroxoline is greater against Candida albicans than against Torulopsis glabrata, Candida tropicalis and Candida krusei. The MIC are compatible with urinary concentrations of nitroxoline. These preliminary clinical results favor the use of nitroxoline in the management of fungal urinary tract infections.

Litomosoides carinii infection in cotton-rats before and after treatment with diethylcarbamazine and suramin: evolution of free serum antigens.

Immunoelectrodiffusion was used to detect free serum antigens after treatment with diethylcarbamazine (DEC) and Suramin (S) in 30 cotton-rats infected with Litomosoides carinii. Precipitin lines between an antiserum produced by an adult worm extract and the test serum indicated the presence of free antigens in the serum. The number of precipitin lines was between one and 3. Before treatment only 13.3% of infected rats were positive compared with 83.7% after treatment. There was a difference in the delay before the appearance, the persistence and, possibly, the nature of antigens liberated by DEC and S treatment. With DEC release occurred earlier than with S and the antigens persisted for a shorter time. With combined DEC + S therapy the results were similar to those obtained with DEC and S used alone.