Characterization of a newly isolated phage infecting pathogenic Escherichia coli and analysis of its mosaic structural genes

Qin Peng,Yihui Yuan

doi:10.1038/s41598-018-26004-4

Abstract

The outbreak of multidrug-resistant pathogenic bacteria made the discovery of novel control strategies necessary. Phages have regained attention for their specific lytic activity against pathogenic bacterium. A newly isolated phage infecting the clinical Escherichia coli isolates, including several multidrug-resistant strains, was isolated, and this phage showed high control effects against the tested pathogenic E. coli strains. Host range analysis revealed that although the phage exhibited broad lytic spectrum against the tested E. coli strains, it could not lyse strains from the other species. Comparative genomic analysis showed that phages had undergone at least three genome recombination events during the evolutionary process at the position of the three phage tail genes, which was reported to be associated with the host range determination of the phage. The recombinant tail proteins contained functional domains that were highly similar with genes of the Salmonella phage and genes of Pseudomonas and Neisseria. The findings of this study not only provide resources for developing phage therapy against E. coli, but also showed the highly variable genome structure of the phage.

Highlights

Escherichia coli is a type of Gram-negative bacterium of the Enterobacteriaceae family, the majority of which reside in the human gastrointestinal tract as a part of the normal flora
Galtier M. et al utilized a single dose of a cocktail, which consisted of three phages, led to a sharp decrease of E. coli levels throughout the gut[10]
The results indicated that the gene gp[53] might have encountered horizontal gene transfer and gene recombination during the evolutionary process of the phage

Summary

Introduction

Escherichia coli is a type of Gram-negative bacterium of the Enterobacteriaceae family, the majority of which reside in the human gastrointestinal tract as a part of the normal flora. Production of extended-spectrum β-lactamases (ESBL), found in some strains of Enterobacteriaceae, are one of the resistant mechanisms, which act as a worldwide threat These species are chief culprits that cause treatment failure, including infections of the urogenital tract, abdomen, and bloodstream[3]. Galtier M. et al utilized a single dose of a cocktail, which consisted of three phages, led to a sharp decrease of E. coli levels throughout the gut[10]. These studies suggest that the E. coli phage has high potential to be used in controlling pathogenic E. coli, especially multidrug resistant E. coli. The finding of this study increases our understanding on E. coli phage diversity and provides resource for controlling pathogenic E. coli infections

Methods

Results

Conclusion