ABSTRACT
The number of infections caused by antibiotic-resistant strains of bacteria is growing by the year. The pathogenic bacterial species Enterococcus faecalis and Enterococcus faecium are among the high priority candidate targets for the development of new therapeutic antibacterial agents. One of the most promising antibacterial agents are bacteriophages. According to the WHO, two phage-based therapeutic cocktails and two medical drugs based on phage endolysins are currently undergoing clinical trials. In this paper, we describe the virulent bacteriophage iF6 and the properties of two of its endolysins. The chromosome of the iF6 phage is 156,592 bp long and contains two direct terminal repeats, each 2108 bp long. Phylogenetically, iF6 belongs to the Schiekvirus genus, whose representatives are described as phages with a high therapeutic potential. The phage demonstrated a high adsorption rate; about 90% of iF6 virions attached to the host cells within one minute after the phage was added. Two iF6 endolysins were able to lyse enterococci cultures in both logarithmic and stationary growth phases. Especially promising is the HU-Gp84 endolysin; it was active against 77% of enterococci strains tested and remained active even after 1 h incubation at 60 °C. Thus, iF6-like enterococci phages appear to be a promising platform for the selection and development of new candidates for phage therapy.
Subject(s)
Bacteriophages , Caudovirales , Bacteriophages/genetics , Bacteriolysis , Anti-Bacterial Agents/pharmacology , Bacteria , Enterococcus faecalisABSTRACT
Pseudomonas syringae BIM B-268 is the strain used for in vitro testing of the efficiency of Multiphage, a bacteriophage-based biopesticide produced in Belarus. The genome sequence of this strain consists of a single circular chromosome harboring the genes encoding the ice nucleation protein, syringopeptin biosynthesis, and types III and VI secretion systems.
ABSTRACT
Bacillus cereus is a Gram-positive rod-shaped spore-forming bacterium widespread in different environmental niches. Here, we report the complete genome sequence of Bacillus cereus VKM B-370 from the All-Russian Collection of Microorganisms, the host strain for bacteriophages vB_BtS_B83, vB_BcM_Sam46, vB_BcM_Sam112, and Izhevsk.
ABSTRACT
Phytopathogenic pseudomonads are widespread in the world and cause a wide range of plant diseases. In this work, we describe the Pseudomonas phage Pf-10, which is a part of the biopesticide "Multiphage" used for bacterial diseases of agricultural crops caused by Pseudomonas syringae. The Pf-10 chromosome is a dsDNA molecule with two direct terminal repeats (DTRs). The phage genomic DNA is 39,424 bp long with a GC-content of 56.5%. The Pf-10 phage uses a packaging mechanism based on T7-like short DTRs, and the length of each terminal repeat is 257 bp. Electron microscopic analysis has shown that phage Pf-10 has the podovirus morphotype. Phage Pf-10 is highly stable at pH values from 5 to 10 and temperatures from 4 to 60 °C and has a lytic activity against Pseudomonas strains. Phage Pf-10 is characterized by fast adsorption rate (80% of virions attach to the host cells in 10 min), but has a relatively small number of progeny (37 ± 8.5 phage particles per infected cell). According to the phylogenetic analysis, phage Pf-10 can be classified as a new phage species belonging to the genus Pifdecavirus, subfamily Studiervirinae, family Autographiviridae, order Caudovirales.
Subject(s)
Bacteriophages/physiology , Biological Control Agents , Crops, Agricultural , Plant Diseases/prevention & control , Pseudomonas Phages/physiology , Pseudomonas syringae/virology , Bacteriophages/classification , Bacteriophages/genetics , Bacteriophages/isolation & purification , Base Composition , Caudovirales/genetics , Crops, Agricultural/microbiology , DNA, Viral/genetics , Genome, Viral , Host Specificity , Phylogeny , Plant Diseases/microbiology , Podoviridae/genetics , Pseudomonas Phages/classification , Pseudomonas Phages/genetics , Pseudomonas Phages/isolation & purification , Siphoviridae/genetics , VirionABSTRACT
The Enterococcus faecium FS86 genome consists of a 2,685,395-bp chromosome and a 9,751-bp plasmid. The plasmid harbors mobilization-related genes. The pathogenicity factor genotype is cylA negative, aggA negative, gelE negative, sprE negative, esp negative, eep positive, and efaA positive. E. faecium FS86 belongs to multilocus sequence type 296, together with the probiotic strain E. faecium SF68.
