Efeito antimicrobiano e antibiofilme da clorpromazina contra cepas de klebsiella pneumoniae multirresistentes isoladas em um hospital universitário

Abstract

Multidrug-resistant Klebsiella pneumoniae (KP) is considered a threat to global health, since it is not susceptible to conventional antimicrobials, making the search for new antibiotics increasingly necessary. However, registration of new antimicrobials grows at a much slower pace than antimicrobial resistance. Therefore, the repositioning of drugs has been a strategy for the search for new antimicrobial agents. In this context, antipsychotics and antidepressants have revealed potential antimicrobial activities and among these stands out Chlorpromazine (CPZ), which has been studied for this property since the 1970s, demonstrating action against a range of microorganisms. Therefore, this work aims to evaluate the in vitro antimicrobial activity of CPZ in clinical strains of multiresistant KP isolated at the Walter Cantídio University Hospital (HUWC), located in the city of Fortaleza, Ceará. The Minimum Inhibitory Concentrations (MIC's) of CPZ were determined against the nine strains of KP used in the study. The biofilm formation profile of the strains was analyzed, as well as the action of CPZ on the metabolic activity and biomass of the biofilm-forming strains. The value of 33.48 μg/mL was found as the geometric mean of MICs, ranging from 4.88 μg/mL to 156.25 μg/mL. Of the nine strains in the study, two of them were classified as strong biofilm formers and three of them as moderately former. There was a significant increase in MIC for CEMB, which was the same for all strains, with a value of 156.25 μg/mL. CPZ also showed the ability to reduce microbial biomass in the range of 1250 μg/mL to 78.12 μg/mL, reducing biomass by almost 96% at a concentration of 312.5 μg/mL. In summary, the antimicrobial potential of CPZ was revealed, however, more studies are needed to evaluate the mechanisms by which CPZ effectively acts as an antimicrobial