Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Associated with Nosocomial Infection in the Pelotas, RS, Brazil

Biogenic silver nanoparticle (Bio‐AgNP) has an antibacterial effect against carbapenem‐resistant Acinetobacter baumannii with synergism and additivity when combined with polymyxin B

“…A recent study evaluated the toxic effect of Bio-AgNPs in mammalian cells, and the results of the selectivity index (SI) showed their viable application in the medical area (Figueiredo et al, 2019). In another study, the cytotoxicity of Bio-AgNPs was evaluated in RK13 cells (rabbit kidney cell), which evidenced a cytotoxicity threshold between 0.6 and 5 µg/ml within 24 h, suggesting that these concentrations of Bio-AgNPs pose no risk of toxicity to mammalian cells (Valente et al, 2018). In our study, both Bio-AgNP and polymyxin B exhibited a concentration-dependent cytotoxic activity.…”

“…(3) AgNPs inducing cellular toxicity and oxidative damage by generating reactive oxygen species (ROS) and free radicals and (4) modulating signal transduction pathways (Bocate et al, 2019;Dakal et al, 2016;Valente et al, 2018;Durán et al, 2019;Figueiredo et al, 2019;Scandorieiro et al, 2016;Zhang et al, 2016). Silver ions delivered by the nanoparticles to bacteria increase membrane permeability, interrupting the formation of disulfide bonds in the inner membrane leading to the production of ROS and promoting lysis, a process by which cells die (Abbasi et al, 2016;Hossain et al, 2019;Jasim et al, 2017;Lu et al, 2020).…”

“…These strains belong to the Laboratory of Bacteriology and Bioassays (LaBBio), Federal University of Pelotas (UFPel) and were kindly provided to us by the Microbiology Laboratory of School Hospital, Federal University of Pelotas (UFPel). Bacterial strains evaluated in this study were previously characterized and have different genetic patterns (Freitas et al, 2020). Selected isolates were maintained at −20°C in Brain Heart Infusion (BHI) broth with 10% glycerol and then subcultured on MacConkey agar for 24 h before testing.…”

“…The synthesis of AgNPs can be applied by a series of methodologies, but biological synthesis stands out as the best approach since its routes have several advantages; it is simple, economical and ecologically correct and shows high performance. Also, it uses the so-called green or biogenic technology that generates nontoxic products (Valente et al, 2018;Siddiqi et al, 2018).…”

Capacidade de formação de biofilmes e perfil de resistência de Acinetobacter baumannii isolados em unidades de terapia intensiva: uma revisão sistemática

“…No Brasil, têm sido demonstrados diversos isolados de A. baumannii resistentes aos carbapenêmicos, limitando o tratamento aos antimicrobianos de última linha, como as polimixinas, que levam a efeitos nefrotóxicos importantes em 36 % dos pacientes [34,35]. Dessa forma, compreender os mecanismos associados à resistência pode ajudar na implementação de medidas para controlar e prevenir a aquisição de infecções nosocomiais, especialmente em UTIs, além de desempenhar um papel essencial no desenvolvimento de estratégias terapêuticas [33,34].…”