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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #418085
Research Project: Intervention Strategies to Control Salmonella and Campylobacter During Poultry Processing

Location: Poultry Microbiological Safety and Processing Research Unit

Title: Synergistic effects of polyphenols and antibiotics against multi-drug resistant salmonella typhimurium DT104

Author
item SHEFFIELD, HUNTER - Auburn University
item RODRIGUEZ CHINCHILLA, KAROLL - Auburn University
item BHARATHAN, GREESMA - Auburn University
item HAYDEN, MICHELE - Auburn University
item MADI, AISHA - Auburn University
item Buhr, Richard
item SRIKUMAR, SHABARINATH - Auburn University

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 11/25/2024
Publication Date: 1/27/2025
Citation: Sheffield, H., Rodriguez Chinchilla, K.E., Bharathan, G., Hayden, M., Madi, A., Buhr, R.J., Srikumar, S. 2025. Synergistic effects of polyphenols and antibiotics against multi-drug resistant salmonella typhimurium DT104. International Poultry Scientific Forum. 104:34.

Interpretive Summary:

Technical Abstract: The rise of antimicrobial-resistant foodborne pathogens necessitates innovative approaches to enhance the efficacy of existing antibiotics. This study explores the synergistic effects of Phyto polyphenols, specifically hydroxycinnamic acid, and itaconic acid, with conventional antibiotics in inhibiting the growth of multi-drug resistant Salmonella enterica serovar Typhimurium, DT104 (DT104). We used DT104 due to its resistance to five antibiotics, which allowed us to test the multi-antibiotic polyphenol synergy. Initially, the minimum inhibitory concentrations (MICs) of the polyphenols were determined individually using the standard 96-well plate microdilution protocol. Following this, a checkerboard assay was performed to assess potential synergistic interactions between each polyphenol and different antibiotics. Both hydroxycinnamic acid and itaconic acid showed no significant anti-DT104 effect when tested individually. However, when tested in the presence of antibiotics, both polyphenols showed excellent anti-DT104 effects showing synergy with all the tested five antibiotics demonstrating synergy with all the tested five antibiotics resulting in a reduction in the individual antibiotic MIC.. We also tested the practical application of our observation on meat samples. One-gram portions of boneless, skinless chicken tenders were inoculated with DT104. The samples were treated with hydroxycinnamic acid and itaconic acid, while control samples received no treatment (PBS). The treated and untreated samples were incubated, rinsed, and then plated on XLD at 2-hour intervals over a 16-hour period to assess bacterial growth. Our results indicated a significant reduction in the growth of DT104 in samples treated with polyphenols compared to the untreated controls. This reduction highlights the potential of polyphenols to enhance the effectiveness of antibiotics against multi-drug resistant pathogens in food matrices. It is important to note that even though individual polyphenols did not show any anti-DT104 effect in the MIC analysis, there were significant antimicrobial effect on chicken meat. This could be because of the hurdle principle wherein the meat produced some stressful environments for DT104 in the presence of our polyphenols. These preliminary findings suggest that polyphenols can be crucial in mitigating the risk of foodborne illnesses caused by pathogenic bacteria.