JAC Advance Access originally published online on February 14, 2008
Journal of Antimicrobial Chemotherapy 2008 61(4):853-858; doi:10.1093/jac/dkn024
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Original research |
Antimicrobial activity of lupulone against Clostridium perfringens in the chicken intestinal tract jejunum and caecum
1 Agricultural Research Service, United States Department of Agriculture, Poultry Microbiological Safety Research UnitRussell Research Center, Athens, GA, USA 2 School of Natural Sciences, Fairleigh Dickinson University, Teaneck, NJ, USA 3 S.S. Steiner, Inc., New York, NY, USA 4 Department of Poultry Science, University of Georgia, Athens, GA, USA 5 bioMérieux, Bacterial Barcodes, Inc., Athens, GA, USA
Received 16 August 2007; returned 8 October 2007; revised 7 December 2007; accepted 7 January 2008
* Correspondence address. Agtech Products, Inc., W227 N752 Westmound Dr, Waukesha, WI 53186, USA. Tel: +1-262-521-1717; Fax: +1-262-521-2442; E-mail: gsiragusa{at}agtechproducts.com
Objectives: Owing to the spread of antibiotic resistance among human infectious agents, there is a need to research antibiotic alternatives for 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 perfringens. Hop (Humulus lupulus) bitter acids are known to possess potent antimicrobial activity. Lupulone was evaluated for in vivo antimicrobial activity to inhibit C. perfringens in a chick gastrointestinal colonization model.
Methods: Using a week-2 per os inoculated C. perfringens chicken colonization model, C. perfringens counts in mid-intestinal and caecal contents were compared between chickens administered lupulone at 62.5, 125 and 250 ppm in drinking water versus 0 ppm control.
Results: At day 22, post-hatch intestinal C. perfringens counts of lupulone-treated chickens were significantly lower (P < 0.05) than water-treated control groups in both jejunal and caecal sampling sites across all lupulone dosages tested.
Conclusions: Lupulone administered through water inhibits gastrointestinal levels of inoculated pathogenic clostridia within the chicken gastrointestinal tract. Lupulone was effective within the chemically complex mixture of material within the gastrointestinal tract, thereby making this agent a target of further research as an antibiotic alternative for this and possibly other intestinal infections.
Keywords: Humulus lupulus , hops , β-acids , plant-derived antimicrobials , antibiotic alternatives , poultry necrotic enteritis , Clostridium spp.