Verificação da variação fenotípica de isolados de Pseudomonas aeruginosa expostos a antimicrobianos de uso veterinário

Abstract

The One Health perspective acknowledges the interconnection between human, animal, and environmental health. Antimicrobial resistance is a global challenge and affects humans and animals with significant impacts. This study investigated the responses of six isolates of Pseudomonas aeruginosa to two formulations of veterinary antimicrobials under different Chemical Oxygen Demand (COD) on biofilm formation, motility and pyocyanin production. There were tests 16 conditions. The hydrophobicity of the cell wall ranged from 91% up to 110%. Pyocyanin production was between 1.46 up to 3.26 μg/L. Biofilm of the isolate JVD 05 reduced 83.3% inhibition of biofilm with the combination of 0.15/0.12 mg/mL of florfenicol and sulfamethoxazole-trimethoprim. Biofilm adherence, however, increased for JVD 05 and JVD 07 when florfenicol was tested alone (0.30 mg/mL). DQO has influenced significally in the results. Regarding antimicrobial resistance, it was observed that at higher concentrations of sulfamethoxazole- trimethoprim (0.24 mg/mL) for isolate JVD 05, there were significant levels of resistance, especially under DQO conditions of 2,000 and 20,000 mg/L. The presence of florfenicol (0.30 mg/mL) and the absence of sulfamethoxazole-trimethoprim showed resistance compared to the condition of 20,000 mg/L DQO. However, the low DQO level, specifically 400 mg/L, did not seem to contribute to resistance. Additionally, in the presence of florfenicol (0.30 mg/mL), isolate JVD 05 experienced a significant reduction in motility after 24 hours, with reductions of 100% in swimming motility, 82.8% in swarming motility, and 77% in twitching, compared to controls. Florfenicol promoted the formation of biofilms classified as strong adherence in waters with higher organic matter load. Elevated concentrations of florfenicol resulted in a significant increase in Pseudomonas aeruginosa adherence.