Scientific Journal of KubSAU

In this work, we have found shortened particle forms of the filamentous bacteriophage Pf, when the lysis of the Pseudomonas aeruginosa PAO1 strain was induced by extracts of bison feces to study the intestinal bacteriophages of this animal. The sizes of the shortened particles from 250 to 950 nm and their thickness 17 nm were determined. The particles had a slightly pointed one end and sometimes a flag on the other extended end. The particles were formed in the process lysis of this strain by other bacteriophages. These lysates also contained a high concentration of vesicles from the pseudomonad membrane. The article discusses the mechanisms of prophage induction in the Pseudomonas aeruginosa PAO1 strain due to phage-phage induction and substances of the investigated extract

This work considers the needs and methods of phage therapy of two bacterial infections in poultry. The review examines the use of bacteriophages, from the moment of their discovery to the present day. We discuss the relevance of such diseases as compilobacteriosis and colibacteriosis transmitted from birds to humans, we show how to use bacteriophages and their efficacy in models of adult birds and chickens, including information provided on the pilot study of phage therapy at a poultry farm. The reported study was partially supported by RFBR, research projects No. 16-44-230855 and No. 13-04- 00991 and № 16-44-230855-р_а

In the review, the stages of designing therapeutic cocktails of T4 type bacteriophages based on works by Harald Brüssow from Nestlé S.A. (Switzerland) are considered. The main stages of this process are identified: analysis of existing cocktails, selection of phages; creating a collection; cultivation of the host bacterium, multiplication of viruses; purification of the preparation; contamination testing; preservation, stabilization and storage; preclinical and clinical trials. H. Brüssow first studied the Russian drug " Coli-Proteus bacteriophage " of "Microgen" with the help of metagenomic analysis, electron microscopy and conducted its clinical studies. Prof. Brüssow considered the advantages of T4 bacteriophages for the treatment of Escherichia coli infections. Researchers studied methods of cultivation in Erlenmeyer flasks, in a bioreactor, in disposable sack cultivators for the propagation of viruses. For its purification the chromatography, centrifugation, filtration and polyethylene glycol precipitation were studied. To quickly check the contamination of phage cocktails, a mass spectrometry method is proposed. Researchers considered basic strategies, such as lyophilization, spray drying, the formation of microcrystals and microspheres to stabilize the preparations. They also reviewed the results of clinical trials of phage cocktails. We have listed the problems of selecting T4 bacteriophages from the point of view of modern knowledge. H. Brüssow and his colleagues carried out an interesting work on the construction of phage cocktails based on T4 type bacteriophages, and also revealed the problems of the current state of phage therapy

The isolation of E.coli phages from samples of natural and waste water obtained during expeditions in the different regions of Russian Federation was carried out. The obtained phages (286 isolates) were tested for their ability to lyse the pathogenic strains of E. coli – pathogenic agents of pig colibacteriosis in Krasnodar region. The study was conducted of their ability to phage transduction, the molecular-genetic characterization and biotechnological parameters of selected bacteriophages. For first experimental design of veterinary drugs was selected 5 coliphages having no ability of plasmids transduction. It has been shown that all the investigated phages are representatives of T4-type phages of family Myoviridae. The reported study was partially supported by RFBR, research projects No. 08-04-99111, 09-04-10132, 16-44- 230855

A method of obtaining insertion mutants for the hoc gene, which encodes for the main phage antigen, was developed on the model of bacteriophage T4. This gene was cloned in the plasmid pBSL0+ and was disrupted by insertion of foreign DNA. The phage mutants were obtained by in vivo phage-plasmid recombination. The construction of insertion bacteriophage mutants was carried out in two stages. The resulting mutants on this procedure could be grown on wild-type E. coli strains, which is convenient for the production and use of these phages in therapy. The mutants obtained had reduced antigenicity. At the same time, the yield of the mutant strains was high when they were grown on the non-suppressor E. coli laboratory strains. A number of stages of purification of the bacteriophage mutants obtained were performed. Preparations have been studied by transmission electron microscopy and mass spectrometry. By several periodic cultivations of the mutant bacteriophages, it was shown that mutations of this type are stably maintained during more than 50 generations. T4 related bacteriophages of the family Myoviridae, for example, T-even, have the significant homology amongst their genomes, which makes possible to produce similar mutants. Thus, our method was developed to obtain mutants with reduced antigenicity which can be used for both the treatment of systemic infections, and diarrhea in the case, when, bacteriophages penetrate into the bloodstream. Such phages can be used in medicine and veterinary. The reported study was partially supported by RFBR, research projects No. 13-04-00991, 16-44-230855

The influence of four experimental phage preparations, designed based on non-transducing E. coli bacteriophages on pigs with post-weaning diarrhea studied. The influence of these phages in depending by methods of its applying (per os and intra cutis) on coli-titer and coli-phages titer studied. It is established, that the best survival rate and the clinical condition showed animals treated with the E. coli phage T4-type with lab. number «8» (till 5,52 lg CFU/g at 37-days age) in parallel with an increase in titer of phages (till 5,73 lg CFU/g at 40-days age). Intradermal (intra cutis) method of applying of experimental phage preparations (constructed on basis of phage “6” and phage “8”) showed the some positive effects on correction of negative dynamics of coli-phages titer in control group

Studied the investigation of the therapeutic effect of experimental mixture of four non-transducing E. coli bacteriophages and it combinations with probiotic, designed on the basis of the endemic Lactobacillus paracasei strain, previously isolated from pigs in this age of the local population in the state, the survival rate and laboratory parameters of pigs with post-weaning diarrhea. The most influence on the correction of E. coli dynamics has a combined oral administration of phage medicine and probiotic preparation established. The most influence on the dynamics of titer phages has not only the combined using (both oral and intradermal) of phage medicine with the probiotic preparation, but also an isolated ingestion of phage mixture