Investigating the in-vitro antimicrobial activities of sorghum [Sorghum bicolor (L.) Moench] phenolic extracts on liver abscess causing bacterial pathogens

Authors: SALIH, HARITH - Kansas State University; AMACHAWADI, RAGHAVENDRA - Kansas State University; KANG, QING - Kansas State University; Smolensky, Dmitriy; PERUMAL, RAMASAMY - Kansas State University; BOWSER, SARAH-SEXTON - Kansas State University; PRASAD, P. V. VARA - Kansas State University; NAGARAJA, T. G. - Kansas State University

Submitted to: Frontiers in Cellular and Infection Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2025
Publication Date: 6/26/2025
Citation: Salih, H.M., Amachawadi, R.G., Kang, Q., Smolensky, D., Perumal, R., Bowser, S., Prasad, P., Nagaraja, T. 2025. Investigating the in-vitro antimicrobial activities of sorghum [Sorghum bicolor (L.) Moench] phenolic extracts on liver abscess causing bacterial pathogens . Frontiers in Cellular and Infection Microbiology. Volume25:Front. Cell. Infect. Microbiol. 15:1568504. https://doi.org/10.3389/fcimb.2025.1568504.
DOI: https://doi.org/10.3389/fcimb.2025.1568504

Interpretive Summary: When cattle are fed a high grain diet in the finishing stage, liver abscesses occur causing significant economic damage. The major bacterial species responsible for liver abscesses are Fusobacterium necrophorum subspecies (necrophorum and funduliforme), Trueperella pyogenes, and Salmonella enterica serotype. Treating cattle with antibiotics in order to reduce liver abscesses raises concern for developing antibiotic resistance. This study investigated the potential of sorghum grain polyphenols to reduce the viability of these bacteria inside a laboratory. Sorghum phenolic extracts reduced the amount of viable bacteria in usobacterium necrophorum subspecies (necrophorum and funduliforme) and Trueperella pyogenes but not in Salmonella enterica serotype Lubbock when compared to solvent control. These results indicate the the addition of high polyphenol sorghum grain or high polyphenol sorghum extract has the potential to reduce liver abscesses in cattle. More research is needed.

Technical Abstract: Liver abscesses that occur in finishing cattle fed high-grain, low-roughage diets, are of significant economic concern to the feedlot industry. The causative agents include both Fusobacterium nec-rophorum subspecies (necrophorum and funduliforme), Trueperella pyogenes, and Salmonella enterica serotype Lubbock. Tylosin, a macrolide antibiotic, is supplemented in the feed to reduce liver ab-scesses. Because of the concern with emergence of potential antimicrobial resistance, there is a need to find antibiotic alternatives. The aim of our study was to investigate the efficacy of phenolic compounds extracted from black and brown sumac sorghum extracts on liver abscess causing bacterial pathogens. Phenolic compounds were extracted by 75% aqueous acetone and total phe-nolic content was determined spectrophotometrically. Muller-Hinton broth (for S. enterica and T. pyogenes), and anaerobic Brain–Heart infusion broth (for Fusobacterium) with and without sorghum extracts (1 mg GAE/mL) were used. Growth was measured at 24 and 48 hours to determine bac-terial concentration. Micro-broth dilution method was used to quantify growth inhibition. Plant based phenolic compounds have the potential to be an antibiotic alternative to control liver ab-scesses. Sorghum [Sorghum bicolor (L.) Moench] grain phenolic compounds, have the potential to be one of these alternatives. Our study demonstrated that the phenolic extracts of black and brown sumac sorghum exhibited antibacterial activities against the liver abscesses causing pathogens in-cluding the both subspecies of Fusobacterium necrophorum and Trueperella pyogenes in a dose de-pendent manner, but not S. enterica. Sorghum phenolic compounds may have the potential to be supplemented in the feed to control liver abscesses.