Aeromonas hydrophila causes necrotising disease in mammals and fish. It carries antimicrobial resistant markers and facilitates their movement between fish, poultry and humans. In humans, it causes necrotising fasciitis and sepsis in immunocompromised individuals. Its control is therefore cardinal in health and food security.
Wastewater samples collected weekly across Bendigo were screened. Isolated bacteriophages were tested against different clinical Aeromonas hydrophilia isolates implicated in sepsis. Initial genetic characterisation of isolated bacteriophages was performed using restriction enzyme digestion on extracted bacteriophage DNA and illumina whole genome sequencing.
Using a select range of four, five and six base cutters, restriction enzyme digestion revealed three distinct bacteriophages. Full genomic sequences and functional gene characterisation data reveal novel sequences with 85% similarity to published Ahp1 Podovidiridae phage. Functional host range analysis has revealed differing lytic capacities and multiplicities of infection against a range of Aeromonas hydrophilia isolates. The bacteriophages have shown stability in broth at 4oC for three months with minimal loss of efficacy.
To date there have only been a few reports of lytic bacteriophages against Aeromonas hydrophilia, and to our knowledge, those described here are the first isolated, characterised and lytic for clinical isolates of this bacteria. We plan to use in vivo mouse sepsis models to assess the capacity for these bacteriophages to lyse Aeromonas in the bloodstream. Lytic bacteriophages against Aeromonas hydrophilia can be isolated from wastewater and potential exists for testing in the control of Aeromonas in agricultural livestock, as well as testing in the treatment of sepsis in humans.