Abstract
BACKGROUND AND AIM: Fowl cholera, caused by multidrug-resistant (MDR) Pasteurella multocida type A, poses a significant threat to chicken production globally. This study investigates the potential of ethanolic extracts from Wild Egyptian Artichoke (WEA) (Cynara cardunculus L. var. sylvestris) to modulate virulence-associated genes and provide an alternative control strategy. MATERIALS AND METHODS: A total of 160 tissue samples from diseased chickens were collected and analyzed. Phenotypic, biochemical (via Vitek 2 Compact), and molecular methods were used to identify P. multocida. Polymerase chain reaction (PCR) confirmed the presence of key adhesion and colonization genes (omp87, ptfA, pfhA) in MDR isolates. The antimicrobial efficacy of WEA ethanolic extract was assessed using disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Gene expression changes were evaluated using quantitative reverse-transcription PCR after treatment with sub-inhibitory extract concentrations. RESULTS: Eleven isolates (6.9% prevalence) of P. multocida type A were confirmed, with four showing resistance to over five antimicrobial classes. The ethanolic WEA extract demonstrated significant antibacterial activity, with inhibition zones of up to 25 mm, MIC values ranging from 4 to 16 µg/mL, and MBC values between 8 and 32 µg/mL. Gene expression analysis revealed up to threefold downregulation in omp87 (0.28-fold), pfhA (0.25-fold), and ptfA (0.12-fold) after treatment. CONCLUSION: The WEA ethanolic extract effectively downregulates critical virulence genes in MDR P. multocida, highlighting its potential as a novel natural agent for controlling fowl cholera in chicken. This study emphasizes the importance of exploring plant-based antimicrobials to combat resistance and improve animal health.