Isolation and Characterization of Jumbo Coliphage vB_EcoM_Lh1B as a Promising Therapeutic Agent against Chicken Colibacillosis.

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.

Isolation and Characterization of Lytic Bacteriophages Active against Clinical Strains of E. coli and Development of a Phage Antimicrobial Cocktail.

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.

Complete Genome Sequence of a Gamaleyavirus Phage, Lytic against Avian Pathogenic Escherichia coli.

We report the complete genome sequence of the lytic bacteriophage vB_EcoS_Uz1, which was isolated from wastewater near Almaty, Kazakhstan using the avian pathogen Escherichia coli host. Its complete genome is 72,583 bp in length, with a GC content of 43%. vB_EcoS_Uz1 belongs to the Gamaleyavirus genus of the Caudoviricetes class.

Complete Genome Sequence of Escherichia-Infecting Phage CEC_KAZ_2018, Isolated from Soil.

Avian pathogenic Escherichia coli (APEC) bacteria are one of the main problems of the poultry industry. An effective way to combat colibacillosis is to use a phage preparation that lyses the bacteria. Here, we report the isolation of an E. coli-infecting phage, CEC_KAZ_2018, isolated from soil.