EVALUATION OF THE ANTIMICROBIAL POTENTIAL OF PLANTS FROM NORTHEAST BRAZIL AGAINST BACTERIA FROM RAW BEEF

Abstract

In Brazil, animal production constitutes a principal economic activity. To enhance productivity, antimicrobials are frequently employed, particularly as growth promoters, which contribute to bacterial resistance to these agents. Consequently, it is imperative to develop novel solutions, particularly natural ones, to mitigate bacterial resistance originating from food sources. Considering this, the present study seeks to characterize and evaluate additives with antimicrobial potential for application in the preservation of meat products. To achieve this objective, a repository of bacterial strains from packaged raw beef was established, followed by morphophysiological identification. The antimicrobial resistance profile was assessed by testing four selected bacterial strains against Imipenem, Azithromycin, Ciprofloxacin, Cefuroxime, and Nisin at varying concentrations, utilizing the Microtitre Broth Dilution Method. Concurrently, aqueous plant extracts from specimens in the Brazilian Northeast were obtained and analyzed for their phytochemical composition, antioxidant activity against DPPH and ABTS free radicals, and synergy for antimicrobial potential, conducted with the antibiotic Imipenem against four bacterial strains. The findings indicated that the packaged raw beef exhibited a microbiological profile of 60.42% Gram-negative and 31.25% Gram-positive bacteria, with increased susceptibility to ciprofloxacin. The phytochemical analysis of the extracts revealed levels ranging from 88.30 to 580.05 mg EAG/L, total flavonoids ranging from 110.04 to 387.48 mg EC/L, and condensed tannins ranging from 102.69 to 422 mg EC/L. Regarding antioxidant activity, the extract from the Caesalpinia pulcherrima plant demonstrated the ability to inhibit the tested free radicals. The synergism test revealed that, in combination with imipenem, the Mimosa tenuiflora plant extract exhibited antimicrobial efficacy against the four samples. Thus, the extracts were found to possess high levels of secondary metabolites, substantial antioxidant capacity, and the potential for use in conjunction with antimicrobials.