METHOD FOR MODELING SYMBIOSIS OF PLAGUE PATHOGEN CELLS WITH SAPROPHYTE MYXOCOCCUS XANTHUS Russian patent published in 2003 - IPC

FIELD: microbiology, ecology. SUBSTANCE: invention relates to methods for modeling symbiosis (biocenosis) of plague pathogen with saprophyte microorganisms and the following detection of cells Yersinia pestis in this symbiosis. On surface of solid nutrient medium cultures Y. pestis and Myxococcus xanthus are plated by streaks in the definite arrangement. After additional cultures growing at 28 C for 48-72 h cells of plague pathogen are detected in fold-pockets of fruit bodies of M. xanthus. Part cells of Y. pestis are lysed inside of fruit bodies but some cells of plague pathogen are adopted to the novel environment inhabitation and persisting in it and even with multiplication, i. e. they show symbiosis. For detection of cells Y. pestis in fruit bodies of M. xanthus method of phage titer rise is used. Samples of bacterial mass of M. xanthus fruit bodies containing with assumption single cells of plague pathogen are incubated preliminary under permissive conditions before addition of specific phage in the definite concentration to cells. Then mixture containing bacterial cells and bacteriophage are cultured again in the same regime and chloroform is added to sample mixtures. Concentration of phage particles is determined in supernatant liquid by Gratia method. The presence of Y. pestis cells where specific phage is reproduced is estimated indirectly by increased phage concentration in sample by 100 and more times. The presence of foreign microflora (soil microorganisms, air flora, intestine and pseudotuberculosis rods) does not interfere for results recording. The developed biological symbiosis model of pathogenic microorganism (Y. pestis) with ubiquitary abundant saprophyte (M. xanthus) and development of method for detection of single cells of plague pathogen in biomass of this association can be used for study of ecological systems and for assay of ecological valence of components that is important for solution of epidemiological problems. EFFECT: improved modeling method. 2 cl, 3 ex