# Antimicrobial Potential of Bacteriophages JG005 and JG024 Against Pseudomonas aeruginosa Isolates from Canine Otitis

## TL;DR

This study shows that two bacteriophages, JG005 and JG024, can reduce Pseudomonas aeruginosa biofilms in canine ear infections, offering a potential new treatment.

## Contribution

The study evaluates the antimicrobial potential of two specific bacteriophages against P. aeruginosa isolates from canine otitis externa.

## Key findings

- JG024 showed lytic activity against 61.2% of P. aeruginosa isolates.
- JG005 achieved higher biofilm reduction than JG024 at certain MOI levels.
- Both phages show promise as innovative treatments for canine otitis externa.

## Abstract

Pseudomonas aeruginosa is a major concern in veterinary medicine due to its antimicrobial resistance and biofilm-forming ability, particularly in canine otitis externa. This study explored the potential of bacteriophages as a therapeutic approach to this disease. Two phages, JG005 and JG024, were tested against P. aeruginosa isolates obtained from dogs with otitis externa. The isolates were first characterized in terms of biofilm production and antibiotic resistance profile. Phage activity was then evaluated for biofilm reduction. JG024 was effective against 61.2% of the isolates, while JG005 showed activity against 39%. JG005 also achieved higher biofilm reduction than JG024. These results highlight the potential of bacteriophages as a promising alternative for treating canine ear infections, reinforcing the need for further studies.

Canine otitis externa caused by Pseudomonas aeruginosa is a relevant disease in veterinary medicine. Given P. aeruginosa’s high priority status for the development of new antimicrobials, innovative strategies like bacteriophage therapy are essential. Lytic bacteriophages are viruses with high specificity for their bacterial hosts, making them a promising therapeutic choice in both human and veterinary medicine. This study aimed to evaluate the antimicrobial potential of bacteriophages JG005 and JG024, first characterized in terms of their biofilm-forming ability and antimicrobial susceptibility profile, against P. aeruginosa isolates obtained from dogs with otitis externa,. Bacteriophages titer, host range, and activity were assessed against P. aeruginosa biofilms via microtiter assays using crystal violet and Alamar Blue. JG024 showed lytic activity against 61.2% (n = 30/49) of the isolates, while JG005 showed lytic activity against 38.8% (n = 19/49) of the isolates. Crystal violet quantification showed that JG005 can promote strong microbial suppression of 60% (n = 6/10) and 50% (n = 5/10) of the isolates at a multiplicity of infection (MOI) of 10 and 100, respectively. JG024 presented strong microbial suppression of 20% (n = 2/10) of the isolates regardless of the MOI level tested. These phages show promising potential as an innovative treatment for canine otitis externa caused by P. aeruginosa, but further studies are needed before future clinical use.