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

TL;DR

This study explores whether phenolic compounds from sorghum can act as an alternative to antibiotics for preventing liver abscesses in cattle.

Contribution

The study introduces sorghum phenolic extracts as a potential natural alternative to antibiotics for controlling liver abscess-causing bacteria in cattle.

Findings

Sorghum phenolic extracts showed antibacterial activity against Fusobacterium necrophorum subspecies and Trueperella pyogenes.

The antibacterial effect was dose-dependent but not observed against Salmonella enterica.

Phenolic compounds from black and brown sumac sorghum could be used in cattle feed to control liver abscesses.

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 necrophorum subspecies (necrophorum and funduliforme), Trueperella pyogenes, and Salmonella enterica serotype Lubbock. Tylosin, a macrolide antibiotic, is supplemented in the feed to reduce liver abscesses. 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 phenolic 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 bacterial 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 abscesses. 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 including both subspecies of F. necrophorum and T. pyogenes in a dose dependent manner, but not S. enterica. Sorghum phenolic compounds have the potential to be supplemented in the cattle feed to control liver abscesses.

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