ABSTRACT
AIM: To study the effect of Enterobactercloacae thermolabile enterotoxin (LT-enterotoxin) on different arms of immune system of mice. MATERIALS AND METHODS: Proprietary clinical strain E. cloacae 258 was used and intraperitoneal inoculation of outbred white mice with LT-enterotoxin-producing E. cloacae comprised experimental model. Phagocytic and lysosomal activity of peritoneal macrophages as well as level of APC to sheep erythrocytes were measured, spontaneous and induced NBT tests were also performed. RESULTS: Pleiotropic immunotoxic effect of LT-enterotoxin of studied bacteria was established, which characterized by suppres- sion of antigen-presenting and antigen-processing functions of macrophages, stimulation of mitotic activity of lymphocytes, decrease of activity of hexose monophosphate shunt enzymes in peritoneal macrophages as well as abnormalities in formation of specific B-lymphocytes. CONCLUSION: Obtained data allowed to reveal separate steps in pathogenesis of infectious process caused by LT-enterotoxin-producing bacteria from Enterobacter genus.
Subject(s)
Enterobacter cloacae/immunology , Enterobacteriaceae Infections/immunology , Enterotoxins/immunology , Animals , Antigen Presentation , Humans , Lysosomes/metabolism , Macrophages, Peritoneal/immunology , Male , Mice , Phagocytosis , Sheep , Temperature , Tetrazoles/metabolismABSTRACT
AIM: To study the role of production of several cytokines by macrophages and neutrophils in experiment. MATERIALS AND METHODS: Production of cytokines--IL-2, 4, 6, 10, 12, 15 as well as interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta) by macrophages and neutrophils during experiment on mice inoculated with enterotoxigenic strain of Enterobacter cloacae was measured. Expression of cytokines was determined by reverse transcription PCR and dot-hybridization on the basis of specially synthesized nucleotide sequences. RESULTS: In macrophages of experimental animals inoculated with enterotoxigenic strain of E. cloacae increased production of TGF-beta, IFN-gamma and decreased level of TNF-alpha were revealed. Transcription of mRNAs of IL-15 and IL-6 was detected in macrophages and neutrophils of experimental animals at 24 h after inoculation. Transcription of mRNAs of IL-2, IL-4 and IL-10 was detected neither in macrophages nor in neutrophils. CONCLUSION: Thermolabile enterotoxin of E. cloacae renders negative effect on IFN-gamma, promotes enhanced expression of TGF-beta and suppresses production of IL-2, IL-4, IL- 10. Absence of expression of key cytokines suggests that effect of thermolabile enterotoxin of Enterobacter bacteria excludes it from cytokine regulation of immune response during infectious process.
Subject(s)
Cytokines/genetics , Enterobacter cloacae/immunology , Enterobacteriaceae Infections/immunology , Enterotoxins/immunology , Gene Expression Regulation , Animals , Macrophages, Peritoneal/immunology , Male , Mice , Neutrophils/immunology , RNA, Messenger/analysisABSTRACT
The comparative study of adhesive, hemolytic, DNA-ase, lecithinase, antilysozymic, anticomplementary activities of mono- and associated cultures of 57 Enterobacter spp., 61 Citrobacter spp. and 55 Serratia spp. strains, isolated from patients with pyoinflammatory, intestinal and urological diseases is carried out. Different variations of cocultivated bacteria including Enterobacter and Citrobacter, Enterobacter and Serratia, Citrobacter and Serratia are used. It was shown, that cocultivated Enterobacter, Citrobacter and Serratia bacteria increased the persistent properties of mixt cultures.
