Antimicrobial Resistance Profile and Antimicrobial Activity of the Methanolic Extract of Pereskia aculeata Mill. against Escherichia coli Strains Isolated from Broiler Chicken Carcasses

Abstract

Objective: This study aimed to evaluate the antimicrobial resistance profile of Escherichia coli strains isolated from broiler carcasses and to assess the antibacterial activity of the methanolic extract of Pereskia aculeata Mill. by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Location and Duration: The research was carried out in a poultry slaughterhouse located in Paraná, Brazil, and at the Laboratory of Preventive Veterinary Medicine and Public Health, Universidade Paranaense, between November 2022 and December 2023. Methodology: Carcass samples were obtained by washing procedures from two broiler farms, collecting 20 samples from each. Enterobacteria were isolated and tested for antimicrobial resistance using the disk diffusion method. Subsequently, the MIC and MBC of the methanolic extract of P. aculeata Mill. were determined. Results: All carcass samples were contaminated with enterobacteria, and one E. coli strain was isolated per sample. No significant differences (P > 0.05) were observed in resistance profiles between farms A and B. Amoxicillin exhibited the highest resistance rate among tested antimicrobials. Multidrug resistance was slightly higher in farm B (30%) compared to farm A (25%). MIC and MBC determination was not feasible, as all strains grew at concentrations ≤ 20 mg/mL. Chemical analysis revealed trans-cinnamic acid (50.13 mg/100 g) and caffeic acid (17.03 mg/100 g) as the major compounds in the extract. Conclusion: Broiler carcasses harbor multidrug-resistant E. coli strains, posing a significant public health concern. The methanolic extract of P. aculeata Mill. failed to inhibit bacterial growth at concentrations up to 20 mg/mL, suggesting that the extraction method may not have been effective under the tested conditions. These findings highlight the urgent need for further studies employing alternative extraction techniques and evaluating bioactive compounds to develop strategies for controlling antimicrobial resistance.