Pradofloxacin shows highest resistance rates among fluoroquinolones in canine Pseudomonas infections analyzed in this systematic review

A limited number of antibiotics are available to treat pathogenic Pseudomonas spp. infections in animals and among currently available antipseudomonal options, only fluoroquinolones can be administered topically, orally and parenterally. We hypothesised that canine Pseudomonas spp. isolates showed higher rates of resistance against fluoroquinolones compared to other antipseudomonal antibiotics. A systematic review and meta-analysis were conducted to determine prevalence and distribution patterns of antimicrobial resistance in Pseudomonas isolates from canine infections. Extracted data were stratified by type of infection, year of isolation, geographical location and tested antibiotics. Seventy-three studies met the inclusion criteria and antimicrobial susceptibility data were derived from 9911 isolates. Approximately 48% of isolates were from otitis externa, while other skin and systemic infections represented 52%. Data were analysed using a mixed effects transformed proportion meta-analysis model. Fluoroquinolones had the highest resistance proportions (0.27, 95% CI [0.22, 0.32]), and pradofloxacin and enrofloxacin had the highest intra-class proportions of resistance, 0.56 (95% CI [0.49, 0.63]) and 0.38 (95% CI [0.32, 0.44]) respectively. In contrast, relatively lower weighted proportions for resistance were observed for aminoglycosides and carbapenems, 0.15 (95% CI [0.11, 0.19]) and 0.08 (95% CI [0.05, 0.12]) respectively. Fluoroquinolones and aminoglycosides are routinely used to treat Pseudomonas spp. infections in dogs, but broad-spectrum beta-lactams are rarely used. These data imply a higher selection pressure for resistance against fluoroquinolones; this may may be exacerbated by use of antibiotics such as enrofloxacin empirically. Antimicrobial susceptibility testing should be used to guide the choice of fluoroquinolones for canine Pseudomonas spp. infections.