Rostov Research Institute for Plague Control, Rostov-on-Don, Russia
Aim. To study toxicity of lipopolysaccharides (LPS28 and LPS 37) of Yersinia pestis for mice sensitized by D-galactosamine (D-GalN). Materials and methods. LPS were obtained by the Westphal method from Y.pestis EV76 strain grown at temperatures of 28 and 37°C. Dexamethasone and pentoxifylline were used as immunodepressants. Uridine was used for interruption of D-GalN effect. Results. It was revealed that administration of D-GalN to mice increased their sensitivity to LPS of Y.pestis. Maximal increase in LPS toxicity was observed after simultaneous administration of D-GalN and LPS. D-GalN in dose 20 mg per mouse determined 100% lethality of animals during 24 h after administration of 10 mcg of LPS28 and 25 mcg of LPS37. Uridine in dose of 20 mcg per mouse administered 1 h after LPS and D-GalN neutralized effect of LPS in the presence of D-GalN. Dexamethasone and pentoxifylline did not protect animals sensitized by D-GalN against lethal effect of Y.pestis LPS. Conclusion. It was found experimentally that D-GalN enhances toxic effect of LPS28 in hundreds of times, and non-toxic LPS37 of Y.pestis EV76 demonstrated toxicity comparable to LPS28. Thus the D-GalN model could be used for enhancement of laboratory animals sensitivity to effect of Y.pestis LPS.
Zh. Mikrobiol. (Moscow), 2011, No. 1, P. 74—76