Zaika S. The biological properties of bacteriophages of phytopathogenic bacteria, members of the families Enterobacteriaceae and Pseudomonadaceae and prospects of their application in the prevention of bacterioses

Thesis is devoted to isolation of lytic bacteriophages specific to plant disease-causing bacteria belonging to the families Enterobacteriaceae and Pseudomonadaceae from the agrocenoses of Ukraine and study of their properties. New lines of bacteriophages capable to lysing Pseudomonas syringae pv. tomato, Serratia marcescens were isolated from the samples of vegetables. The following properties of isolated bacteriophages were studied: latent period and burst size, plaque morphology, host range, efficiency of plating, morphology and sensitivity to environmental factors. It was demonstrated that coinoculation of bacteria with bacteriophages successfully inhibited plant pathogens and prevented development of bacteriosis in vitro and in vivo. It was shown the stability of bacteriophage isolates phiPsy1 phiPsy2 under influence of inactivating environmental factors such as temperature, cations and anions, osmotic shock. It was determined the presence of some opportunistic human pathogens (Proteus mirabilis, Enterobacter cloacae) among phytopathogenic bacteria (Pantoea agglomerans, Pectobacterium carotovorum) in vegetables. Detected bacteria were shown to be resistant to some antibiotics (enrofloxacine, nitrofurantoine, tetraciyline) and may contribute to horizontal spreading of resistances among bacterial populations. Considering the potential risk of opportunistic human pathogens for consumer's health, spesific bacteriophages capable to case the lysis of detected bacteria were isolated from the same samples of vegetables. The results allow for a fresh look at agrocenosis and to create a strategy for the control not only plant pathogenic bacteria, but also those that are able to penetrate into plant and cause infectious diseases in humans and animals consuming vegetable products.