Outbreak of Carbapenem-Resistant High-Risk Clone ST244 of Pseudomonas aeruginosa in Dogs and Cats in Algeria

<b>Background/Objectives:</b> <i>Pseudomonas aeruginosa</i> causes chronic infections in humans and animals, especially cats and dogs. This bacterium's ability to adapt and acquire antibiotic resistance traits may complicate and exacerbate antibacterial therapy. This study aimed to evaluate the antibiotic resistance patterns, virulence factors and ability to form biofilms of <i>P. aeruginosa</i> strains isolated from Algerian dogs and cats. <b>Methods</b>: Nineteen samples were collected from healthy and diseased dogs and cats. Isolates were studied for their antibiotic-resistance patterns (disc diffusion method) and biofilm formation (Microtiter assay) and were whole-genome sequenced (MinION). <b>Results</b>: Nineteen <i>P. aeruginosa</i> strains (15 from dogs and 4 from cats) were isolated. Antibiotic-resistance phenotypes were observed against amoxicillin-clavulanic acid (100%); meanwhile, resistance towards ticarcillin was 40% (dogs) and 25% (cats), ticarcillin-clavulanic acid was 13.33% and 25% for dogs and cats, respectively, and imipenem was 75% (cats) and 20% (dogs). Moreover, 95% of strains were biofilm-producers. Different antimicrobial resistance genes (ARGs) were found: beta-lactamase genes, mainly <i>PAO</i>, <i>OXA-494</i>, <i>OXA-50</i> and <i>OXA-396</i> and an aminoglycoside gene (<i>aph(3')-IIb</i>). The main high-risk sequence types (STs) were ST244, 2788, 388 and 1247. A large panel of virulence genes was detected: <i>exoS</i>, <i>exoT</i>, <i>exoY</i>, <i>lasA</i>, <i>toxA</i>, <i>prpL</i>, <i>algD</i>, <i>rhIA</i> and others. <b>Conclusions</b>: The genetic variety in antibiotic-resistance genes of resistant and virulent <i>P. aeruginosa</i> strains in dogs makes public health protection difficult. Continuous monitoring and research in compliance with the One Health policy are needed to solve this problem.