Avaliação in vitro da atividade antibacteriana de membrana amniótica humana desidratada contra Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen classified as a priority by the World Health Organization (WHO) due to its multiple mechanisms of antimicrobial resistance and high virulence. The human amniotic membrane (AM) has stood out for its regenerative properties and intrinsic antimicrobial activity. The aim of this study was to evaluate the antibacterial and antibiofilm activity of dehydrated human amniotic membrane (AmnioTek™), both alone (AM) and impregnated with ciprofloxacin (AMC), against a clinical isolate of P. aeruginosa. The objectives included assessing antimicrobial and antibiofilm activity, determining whether ciprofloxacin impregnation enhances the effect, and investigating the nature of the soluble factors involved in the AM. The methodology employed disk diffusion assays, biofilm inhibition assays (quantification by crystal violet) after 24 h or 48 h of exposure, scanning electron microscopy (SEM), and evaluation of the AM-conditioned extract (EXT-AM), treated or not with Proteinase K (PK). The disk diffusion assay results showed significantly greater antimicrobial activity for AM-C and ciprofloxacin (CIPRO) compared to AM alone. However, in liquid medium assays, AM, AM-C, and CIPRO demonstrated similar ability to inhibit both planktonic cell growth and biofilm formation, as well as to act on previously established biofilms. The EXT-AM extract demonstrated antimicrobial and antibiofilm activity, which was significantly reduced after PK treatment, indicating that the activity depends on protein -derived components of the AM. SEM confirmed the structural integrity of the AM and revealed morphological alterations in bacteria and cell lysis, as well as biofilm formation on the AM surface. It is concluded that dehydrated amniotic membrane AmnioTek™ exhibits intrinsic antimicrobial and antibiofilm activity against P. aeruginosa, mediated by soluble protein components. This activity was not significantly enhanced by ciprofloxacin impregnation in liquid medium, suggesting that dehydrated amniotic membrane has potential for use as an adjuvant therapy to conventional antimicrobials in the management and prevention of infections.