Potencial antimicrobiano e antibiofilme da clorpromazina contra Pseudomonas aeruginosa e Acinetobacter baumannii multirresistentes

Abstract

Healthcare-Associated Infections (HAIs) are considered a public health problem of great relevance. Factors such as the indiscriminate use of antimicrobial agents and the natural evolution of resistance are drivers in this scenario, corroborating the increase in rates of microbial resistance and mortality associated with hospital infections. The most common microorganisms in HAIs are bacteria, including Pseudomonas aeruginosa and Acinetobacter baumannii, Gram-Negative Non-Fermenting Bacilli (BGNNF), which have the ability to present various mechanisms of resistance to antimicrobials. Together with antibacterial therapy, alternatives to reduce multidrug resistance and collaborate with the antimicrobial effect are becoming increasingly necessary. Therefore, the objective of this work was to evaluate the in vitro antimicrobial and anti-biofilm potential of the antipsychotic agent chlorpromazine against multidrug-resistant isolates of Pseudomonas aeruginosa and Acinetobacter baumannii, belonging to the BGNNF group. For this purpose, sensitivity and association tests of chlorpromazine with ciprofloxacin and gentamicin were carried out in the planktonic form of the bacteria. Furthermore, the activity of the isolated antipsychotic in mature biofilms of both species was evaluated. Sensitivity tests in the planktonic form in P. aeruginosa showed a low variation in terms of Minimum Inhibitory Concentration (MIC), with values between 312.5 and 625 μg/mL. While for A. baumannii, the MIC variation was greater, being between 9.76 and 78.125 μg/mL. Given the association of chlorpromazine with antimicrobials, all strains of P. aeruginosa showed a reduction in MIC, but this same profile did not occur with strains of A. baumannii, in which only two strains showed a reduction. In biofilm tests, chlorpromazine showed a statistically significant reduction (p < 0.05) in microbial biomass only for the species A. baumannii, in 5 of the concentrations tested. Therefore, in this work, the antibacterial and antibiofilm effect of chlorpromazine was detected against the species studied, highlighting this antipsychotic as a promising agent for reducing microbial resistance, but further tests are still needed to analyze the mechanisms involved with this antimicrobial action.