Antagonistic effects of phenolic extracts of Chokeberry pomace on E. coli O157: H7 but not on probiotic and normal bacterial flora

Article type: Research Article

Authors: Aditya, Arpita^{a; 1} | Alvarado-Martinez, Zabdiel^{b; 1} | Nagarajan, Vinod^a | Peng, Mengfei^a | Biswas, Debabrata^{a; b; c; *}

Affiliations: [a] Department of Animal and Avian Sciences, University of Maryland, College Park, MD, USA | [b] Department of Cellular and Molecular Genetics, University of Maryland, College Park, MD, USA | [c] Centre for Food Safety and Security Systems, University of Maryland, College Park, MD, USA

Correspondence: [*] Corresponding author: Dr. Debabrata Biswas, Associate Professor, Department of Animal and Avian Sciences, and Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA. Tel.: +1 301 405 3791; Fax: 301 405 7980; E-mail: dbiswas@umd.edu.

Note: [] 1These authors contributed equally.

Abstract: BACKGROUND:Enterohemorrhagic Escherichia coli (EHEC) is still a major foodborne bacterial infectious agent in the USA and causes both diarrheal disease and hemolytic uremic syndrome (HUS). As antibiotic therapy is not an option, appropriate antimicrobial or inhibitor against EHEC colonization/infections is urgently needed. OBJECTIVE:Develop an appropriate natural antimicrobial and stimulate host defense to control foodborne illnesses with EHEC. METHOD:We investigated the role of chokeberry (Aronia melanocarpa) pomace (byproducts) extract (CPE) on growth and survival of EHEC EDL-933, probiotics specifically Lactobacillus, and other common gut bacterial flora including Streptococcus thermophilus, Enterococcus faecalis and Bacillus subtilis. We also tested the effects of CPE on physicochemical properties, host cells-EHEC interactions, and expression of various virulence genes of EHEC. RESULTS:The growth of EHEC EDL-933 was reduced by 4 logs in the presence of 0.5 mg GAE/mL CPE at 5 hr while this concentration promoted the growth of Lactobacillus and common gut bacterial flora, S. thermophillus, E. faealis and B. subtilis. The abilities of EHEC to attach and invade host intestinal epithelial (INT-407) cells were also reduced significantly (p < 0.05) which was supported by alternation physiological properties of EHEC and virulence genes expression. CONCLUSION:These results suggest that CPE has the potential to be an effective therapeutic/preventive for EHEC EDL-933 without affecting the common gut microflora and probiotics.

Keywords: Chokeberry pomace, enterohemorrhagic E. coli, growth inhibition, cytotoxicity, probiotic

DOI: 10.3233/JBR-190383

Journal: Journal of Berry Research, vol. 9, no. 3, pp. 459-472, 2019