[Choice of probiotic for rational therapy of infection caused by Klebsiella in children].

AIM: To choose lactobacilli-contained probiotic for complex treatment of acute enteric infection caused by Klebsiella in infants. MATERIALS AND METHODS: On the basis of bacteriological analysis the group consisting of 40 infants with acute enteric infection caused by Klebsiella was formed. Efficacy of three probiotic preparations--lactobacterin, vitaflor, and biobacton--was assessed depending on biological features of causative agents and contents of lactobacilli and bifidobacteria in obligate gut microflora. Intraspecies antagonistic characteristics of manufacturing strains of lactobacilli against 9 clinical isolates of K. pneumoniae and 8 strains of indigenous lactoflora, as well as interspecies antagonism between Klebsiella and probiotic and indigenous strains of lactoflora were studied. RESULTS: It was shown that complex therapy of Klebsiella infection in infants using vitaflor or biobacton promoted elimination of K. pneumoniae and restoration of indigenous microflora which became apparent in significant increase of titer of lactobacilli. In vitro maximal antagonism to K. pneumoniae was noted for vitaflor, lactobacterin and heteroenzyme autostrains of ill children's lactoflora. Contrantagonism to lactoflora was typical for slowly growing strains of Klebsiella. CONCLUSION: It is therapeutically rational to use vitaflor, which promotes rapid elimination of infectious agent, in initial phase of acute infection caused by Klebsiella, and biobacton, which increases the titers of indigenous lactoflora, in phase of convalescence.

[Ultrastructural changes in Shigella flexneri cells during interaction with bacteriocinogenic Lactobacillus acidophilus].

Results of electron-microscopic examination of Shigella flexneri cells, subjected to influence the bacteriocin-producing Lactobacillus acidophilus bacteria are presented. The response of shigellae to bacteriocinogenic lactobacilli was shown both on cellular and population levels. On population level the correlation of various morphological types of shigella cells with increase of involution, lysing and resting forms is revealed. At a cellular level the specific ultrastructural changes of shigella evidencing the significant destructive processes of the cells were revealed. In one case destabilization of shigella cellular wall was observed, that was manifested in expansion of periplasmic spaces and appearence of specific involution forms of the cells. In other cases, changes in the ultrastructural organization of shigella nucleoid were found out, manifested in disappearance of thin-fibrillar DNA and formation of electronic-dense globular structures of the cells.

[Antagonistic effect of bacteriocinogenic Lactobacillus acidophilus on Klebsiella pneumoniae, Citrobacter freundii and Proteus mirabilis cells].

Data of the ultrastructural cellular changes of conditionally pathogenic enterobacteria, including K. pneumoniae, C. freundii and P. mirabilis cells impacts to bacteriocin-producing L. acidophilus are presented. Enterobacteria in response to the bacteriocinogenic effect of lactobacilli are manifestated by expressive destructions of sensitive to pore formation bacteriocin cells. Various morphological types of enterobacteria cells with increase of involution, lysing and resting forms are revealed. The specific ultrastructural changes of enterobacteria cells which evidencing the significant destructive processes of the cells membranes are detected. The destabilization of cellular wall in expansion periplasmic spaces and appearance of the ultrastructural reorganization of bacterial cells nucleoid also are registrated. Revealing the mechanism of lactobacilli secreted bacteriocin action to conditionally pathogenic enterobacteria might provide new ways to select the effective highly antagonistic probiotic strains.

[Comparative study of effects of Escherichia coli M-17 exometabolites and fructooligosaccharides on the growth and antagonistic activity of Lactobacilli]. / Sravnitel'noe izuchenie deistviia ékzometabolitov Escherichia coli M-17 i fruktooligosakharidov na rost i antagonisticheskuiu aktivnost' laktobatsill.

Facts concerning the evaluation of the influence of E. coli M17 exometabolites and fructooligosaccharides (FOS) on the growth and antagonistic activity of lactobacilli are presented. As revealed by these facts, preparation "Aktoflor" accelerates the growth of lactobacillary cultures, increases the final yield of biomass and antagonistic activity. E. coli M17 exometabolites contained in "Aktoflor" have been shown to be more active in comparison with FOS. The character of their influence on lactobacilli is discussed and the conclusion is made that the restoration and maintenance of eubiosis is greatly determined by the pool of metabolites excreted by the bacteria.

[Succinate dehydrogenase activity of Escherichia coli cells after heat stress and during the reparative process]. / Suktsinatdegidrogenaznaia aktivnost' kletok Escherichia coli posle teplovogo stressa i v protsesse reparatsii.

The resting cells of different E. coli cells remained viable after their heating at 48 degrees C for 30 min. The activity of their succinate dehydrogenase (SDH) (EC 1.3.99.1) was not more than 50% of the control one. When the cells were inoculated after a heat stress into a peptone medium, they started to grow at a high rate. However, their maximal specific growth rate mu and the overall biomass yield were less than in the control. The SDH activity of the cells reached the original level by the end of the logarithmic growth phase. This did not happen when the cells were incubated in 0.14 M NaCl for a time necessary for the culture to reach the end of the logarithmic growth phase. The SDH activity (in absolute values) of cell-free extracts was not greater than 35% of the cell SDH activity. The SDH activity of the cell-free extracts did not change after their heating at 48 degrees C. The SDH activity of E. coli cells is recommended to be used as a parameter indicative of their stress state.