AUTHOR=Santos Laerte Marlon , Rodrigues Daniela Méria , Kalil Maurício Alcantara , Azevedo Vasco , Meyer Roberto , Umsza-Guez Marcelo Andres , Machado Bruna Aparecida , Seyffert Nubia , Portela Ricardo Wagner 

TITLE=Activity of Ethanolic and Supercritical Propolis Extracts in Corynebacterium pseudotuberculosis and Its Associated Biofilm

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.700030

DOI=10.3389/fvets.2021.700030

ISSN=2297-1769

ABSTRACT=<p><italic>Corynebacterium pseudotuberculosis</italic> is the etiological agent of caseous lymphadenitis in small ruminants, a chronic disease characterized by the development of granulomas in superficial and visceral lymph nodes as well as in several organs. An important characteristic of the infection with this bacterium is the formation of a biofilm and the absence of effective antibiotic therapy against the disease. From this scenario, the objective of this study was to evaluate the susceptibility of <italic>C. pseudotuberculosis</italic> to conventional antibiotics and to red, green, and brown propolis extracts obtained by the supercritical and ethanolic extraction methods as well as its activity in the bacterial biofilm. The results of the sensitivity test using antibiotics indicated a sensitivity of <italic>C. pseudotuberculosis</italic> strains to the antimicrobial agents. The ethanolic extract of green propolis and the supercritical red propolis extract showed the best antibacterial activities against planktonic <italic>C. pseudotuberculosis</italic>. A lower antimicrobial activity of the brown propolis extract was identified. Propolis extracts were effective in interfering with the formation of the <italic>C. pseudotuberculosis</italic> biofilm but had little activity on the consolidated biofilm. In conclusion, propolis extracts are more effective against <italic>C. pseudotuberculosis</italic> in the planktonic stage, being able to interfere with the formation of bacterial biofilm. However, the action of propolis extracts in a sessile and structured microbial biofilm is reduced.</p>