Pathogenic E. coli cause urinary tract, soft tissue and central nervous system infections, sepsis, etc. Lytic bacteriophages can be used to combat such infections. We investigated six lytic E. coli bacteriophages isolated from wastewater. Transmission electron microscopy and whole genome sequencing showed that the isolated bacteriophages are tailed phages of the Caudoviricetes class. One-step growth curves revealed that their latent period of reproduction is 20–30 min, and the average value of the burst size is 117–155. During co-cultivation with various E. coli strains, the phages completely suppressed bacterial host culture growth within the first 4 h at MOIs 10⁻⁷ to 10⁻³. The host range lysed by each bacteriophage varied from six to two bacterial strains out of nine used in the study. The cocktail formed from the isolated bacteriophages possessed the ability to completely suppress the growth of all the E. coli strains used in the study within 6 h and maintain its lytic activity for 8 months of storage. All the isolated bacteriophages may be useful in fighting pathogenic E. coli strains and in the development of phage cocktails with a long storage period and high efficiency in the treatment of bacterial infections.

Colibacillosis in chickens can cause the death of young stock, decrease weight gain and lead to significant economic losses. Currently, antibiotic therapy is the main method of treatment of infected animals, but unchecked use of antibiotics has led to widespread antibiotic resistance among microorganisms. Therefore, it is necessary to develop alternative methods of treating bacterial infections that are fully consistent with the One Health concept and introduce them into practice. Phage therapy meets the specified requirements perfectly. This study describes the isolation and characterization of the lytic jumbo phage vB_EcoM_Lh1B and evaluates its potential use in controlling antibiotic-resistant E. coli infection in poultry. The complete phage genome is 240,200 bp long. Open reading frame (ORF) prediction shows that the phage genome does not contain genes encoding antibiotic resistance and lysogeny factors. Based on phylogenetic and electron microscopic analysis, vB_EcoM_Lh1B belongs to the group of myoviruses of the Seoulvirus genus of the Caudoviricetes class. The bacteriophage has good resistance to a wide range of pH and temperatures and has the ability to suppress 19 out of 30 studied pathogenic E. coli strains. The biological and lytic properties of the isolated vB_EcoM_Lh1B phage make it a promising target of further study as a therapeutic agent against E. coli infections in poultry.

In recent years, the study of marine viromes has become one of the most relevant areas of geoecology. Viruses are the most numerous, genetically diverse and pervasive biological entities on Earth, including in aquatic ecosystems. Information about viral diversity in aquatic ecosystems remains limited and requires more research. This work provides the first-ever look at the current DNA virome of the Northern Caspian Sea. A comparison with other freshwater and marine viromes revealed that the North Caspian Sea virome has the greatest similarity with those of the Baltic Sea and Lake Baikal. The study described in this article expands the knowledge about aquatic viromes and provides key data for a more comprehensive analysis of viruses circulating in the Caspian Sea, the largest inland body of water on Earth.

Streptomyces anulatus is a typical representative of the Streptomyces genus synthesizing a large number of biologically active compounds. In this study, the draft genome of Streptomyces anulatus, strain K-31 is presented, generated from Illumina reads by SPAdes software. The size of the assembled genome was 8.548838 Mb. Annotation of the S. anulatus genome assembly identified C. hemipterus genome 7749 genes, including 7149 protein-coding genes and 92 RNA genes. This genome will be helpful to further understand Streptomyces genetics and evolution and can be useful for obtained biological active compounds.