Diverse bacteriophages for biocontrol of ESBL- and AmpC-ß-lactamase-producing E. coli.

Novel solutions are needed to reduce the risk of transmission of extended spectrum ß-lactamase (ESBL) and AmpC ß-lactamase producing Escherichia coli (ESBL/AmpC E. coli) from livestock to humans. Given that phages are promising biocontrol agents, a collection of 28 phages that infect ESBL/AmpC E. coli were established. Whole genome sequencing showed that all these phages were unique and could be assigned to 15 different genera. Host range analysis showed that 82% of 198 strains, representing the genetic diversity of ESBL/AmpC E. coli, were sensitive to at least one phage. Identifying receptors used for phage binding experimentally as well as in silico predictions, allowed us to combine phages into two different cocktails with broad host range targeting diverse receptors. These phage cocktails efficiently inhibit the growth of ESBL/AmpC E. coli in vitro, thus suggesting the potential of phages as promising biocontrol agents.

A Representative Collection of Commensal Extended-Spectrum- and AmpC-ß-Lactamase-Producing Escherichia coli of Animal Origin for Phage Sensitivity Studies.

Introduction: Extended-spectrum ß-lactamase (ESBL)- and AmpC ß-lactamase (AmpC)-producing Escherichia coli from livestock and meat represent a zoonotic risk and biocontrol solutions are needed to prevent transmission to humans. Methods: In this study, we established a representative collection of animal-origin ESBL/AmpC E. coli as target to test the antimicrobial potential of bacteriophages. Results: Bioinformatic analysis of whole-genome sequence data of 198 ESBL/AmpC E. coli from pigs, broilers, and broiler meat identified strains belonging to all known E. coli phylogroups and 65 multilocus sequence types. Various ESBL/AmpC genes and plasmid types were detected with expected source-specific patterns. Plaque assay using 15 phages previously isolated using the E. coli reference collection demonstrated that Warwickvirus phages showed the broadest host range, killing up to 26 strains. Conclusions: 154/198 strains were resistant to infection by all phages tested, suggesting a need for isolating phages specific for ESBL/AmpC E. coli. The strain collection described in this study is a useful resource fulfilling such need.

Genome Sequences of 16 Escherichia coli Bacteriophages Isolated from Wastewater, Pond Water, Cow Manure, and Bird Feces.

Escherichia coli is a highly diverse bacterial species comprising both commensal and pathogenic strains. Here, we report complete genome sequences of 16 E. coli bacteriophages isolated from various environmental samples using the ECOR collection as isolation hosts.