Avaliação da ação de peptídeos sintéticos derivados de Lippia alba e Lippia rotundifolia no crescimento in vitro da bactéria Brucella abortus

Abstract

The search for new antimicrobial compounds leads many researchers to the development of tool for antimicrobial prospection and design due to the increasing of antibiotic resistance by bacteria. In the present study, three strains of Brucella abortus were used: RB51, S19 and S2308. The bacteria are coccobacilli, gramnegative, facultative intracellular and etiological agents of brucellosis in cattle, buffaloes, humans, sheep, and other animals. The treatment is very difficult and a combination of different antibiotics associated to high antibiotic resistance rates for commonly used drugs against Brucella abortus increases the difficult of microorganism control. Thus, an avenue of opportunities for an extensive research field for antimicrobial agents’ studies is opened. Synthetic peptides are a promising alternative for the development of new antimicrobial agents. In this study, the following synthetic peptides were used: Lalb1.2; Lalb1.3; Lrot3.5; Lrot3.6; Lalb1; Lrot3.7 and Lrot3.8 against Brucella strains. These peptides were developed based on natural characteristics of antimicrobial peptides produced by plants using Lippia alba (Lalb) and Lippia rotundifolia (Lrot) leaf transcritptome for antimicrobial prospection. All peptides showed antimicrobial activity for all of the evaluated concentrations (8, 16,32, 64 and 128 mg/mL). TheLrot3.5 and Lrot3.6 peptides showed antimicrobial activity against all of the three studied strains at the concentration 32μg/mL. These peptides at this concentration do not decrease cell viability of macrophages in tetrazolium reduction (MTT) tests and are prospective peptides for additional studies.