|Buhr, Richard - Jeff|
Submitted to: Antimicrobial Chemotherapy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2008
Publication Date: 2/14/2008
Citation: Siragusa, G.R., Haas, G.J., Matthews, P.D., Smith, R.J., Buhr, R.J., Dale, N.M., Wise, M.G. 2008. Antimicrobial Activity of Lupulone against Clostridium perfringens in the Chicken Intestinal Tract Jejenum and Caecum. Antimicrobial Chemotherapy. 61(4):853-858.
Interpretive Summary: Due to the increase in the number and amounts of antibiotic resistant bacteria in the environment it is imperative that alternative approaches for their control be discovered. Various extracts of plant materials are known to inhibit or kill bacteria. The common hop plant (Humulus lupus) used in human food production has bitter acids known as lupulone that are known to possess potent antimicrobial activity. Clostridium perfringens is a bacterium that causes a severe disease in the chicken gastrointestinal system and also is a cause of human food-borne disease. Chickens were experimentally fed increased amounts of these bacteria that cause disease in both animals and humans. Subsequently, lupulone hops extracts were fed to chickens treated with the bacteria and these birds had significantly lower Clostridium perfringens counts in their gastrointestinal systems than water-fed control groups. These results demonstrate the antimicrobial activity of lupulone administered through water to inhibit gastrointestinal levels of inoculated pathogenic clostridial bacteria within the chicken gastrointestinal tract.
Technical Abstract: Due to the spread of antibiotic resistance amongst human infectious agents, there is a need to search for antibiotic alternatives to use in animal agricultural systems. Antibiotic-free broiler chicken production systems are known to suffer from frequent outbreaks of necrotic enteritis due in part to pathogenic type A Clostridium perfrimgens. Hop plant (Humulus lupus) bitter acids are known to possess potent antimicrobial activity. Lupulone (beta-acids from hop plants) was evaluated for in vivo antimicrobial activity to inhibit Clostridium perfringens in a chick gastrointestinal colonization model. In vivo anti-Clostridial activity of lupulone from the hop plant Humulus lupulus was demonstrated in chickens fed antibiotic-free diets and challenged with strains of Clostridium perfringens. Lupulone was administered by water to 13 day old chickens subsequently challenged per os with necrotic enteritis-associated strains of C. perfringens on each of three subsequent days. C. perfringens counts of mid-intestinal and cecal contents were compared between chickens administered lupulone at 62.5, 125 and 250 ppm in drinking water vs. 0 ppm control. No significant differences between control and lupulone treated groups were observed at day 17 (P>0.05). However, day 22 jejunum/cecal C. perfringens counts of lupulone treated chickens were significantly lower (P<0.05) than water-treated control groups. Within the levels of lupulone tested, no significant (P>0.05) dose response was observed. This demonstrates the potential for lupulone as an antibiotic alternative for clostridial control during poultry production.