ABSTRACT
The sensitivity of 512 newly isolated Pseudomonas aeruginosa clinical strains to six classes of anti-microbial preparations has been studied. Antibiotic-resistant strains were selected and genotyped. Three new virulent bacteriophages of the families Myoviridae and Podoviridae were isolated against these strains. The parameters of the intracellular phage development cycle were established, and the influence of inactivating factors (temperature, pH, and UV exposure) on phage viability was studied. The molecular weight of the phage genome was determined. Phage DNA restriction analysis and polyacrylamide gel electrophoresis in the presence of envelope protein SDS were carried out. The plating efficacy of phages on 28 genetically distant antibiotic-resistant P. aeruginosa strains was studied. It was established that 26 of them were lysed by phages with a high efficacy. The range of antibacterial action of the studied phages and their mixtures on 427 multi-drug-resistant clinical isolates was assessed. It is shown that including these phages in one multicomponent preparation enhanced their lytic activity.
Subject(s)
Genome, Viral , Myoviridae/pathogenicity , Podoviridae/pathogenicity , Pseudomonas Phages/pathogenicity , Pseudomonas aeruginosa/virology , Drug Resistance, Multiple, Bacterial , Genotype , Humans , Hydrogen-Ion Concentration , Lysogeny , Molecular Typing , Molecular Weight , Myoviridae/classification , Myoviridae/genetics , Myoviridae/isolation & purification , Phylogeny , Podoviridae/classification , Podoviridae/genetics , Podoviridae/isolation & purification , Pseudomonas Infections/microbiology , Pseudomonas Phages/classification , Pseudomonas Phages/genetics , Pseudomonas Phages/isolation & purification , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/isolation & purification , Temperature , Ultraviolet Rays , VirulenceABSTRACT
Morphological and biological properties of Salmonella typhimurium phage IRA were studied. The phage is a member of the Styloviridae family and exhibits a very wide spectrum of lytic activity. Molecular cloning of phage genes whose expression is lethal for the host cell has been performed and consequences of gene expression have been investigated. Expression of recombinant plasmid pKI71 causes structural changes of the cell wall and also degradation of host DNA while plasmid DNA remains intact. Expression of pKI72 blocks normal cell division. The possibility of applying such recombinant clones in marking pathways of microbial contamination in water areas is proposed.
