Preliminary insights into the action of non-antibiotic pharmaceuticals in the colonization of Pseudomonas aeruginosa TGC04

Molecules with antimicrobial properties, such as those found in non-antibiotic pharmaceuticals, may pressure bacteria to adapt to the environment. In this work, five of the most sold non-antibiotic pharmaceuticals in Brazil and in Egypt in 2020 (losartan 50 mg, acetylsalicylic acid 100 mg, diclofenac 50 mg, paracetamol 750 mg and metformin 500 mg and dipyrone 100 mg/mL), were tested against the wild strain Pseudomonas aeruginosa TGC04, previously isolated by our group and which has been characterized over the years. We evaluated inhibition of biofilm adhesion over 48 h using the crystal violet test. Exposure of P. aeruginosa TGC04 to the compounds promoted a similar moderate reduction in adherence for all the pharmaceuticals tested, amounting to about 60%. This indicated that the cells were also moderately adherent. However, although all non-antibiotic pharmaceuticals did not produce a biocidal effect on the wild strain, intense antibiofilm activity was observed, except for paracetamol.