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United States Department of Agriculture

Agricultural Research Service

Title: Therapeutic Efficacy of Bacteriophage and Baytril (Enrofloxacin) Individually and in Combination to Treat Colibacillosis in Broilers

Authors
item Huff, William
item Huff, Geraldine
item Rath, Narayan
item Balog, Janice
item Donoghue, Ann

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2004
Publication Date: December 7, 2004
Citation: Huff, W.E., Huff, G.R., Rath, N.C., Balog, J.M., Donoghue, A.M. 2004. Therapeutic efficacy of bacteriophage and baytril (Enrofloxacin) individually and in combination to treat colibacillosis in broilers. Poultry Science. 83:1944-1947.

Interpretive Summary: A study was conducted to evaluate the therapeutic efficacy of bacteriophage and the antibiotic enrofloxacin individually and in combination to treat severe colibacillosis in chickens. Birds were treated with either bacteriophage, enrofloxacin, or both after they were challenged with the bacteria E. coli. The antibiotic treatment was initiated immediately after the birds were challenged and consisted of 50 ppm enrofloxacin in the drinking water for seven consecutive days. The bacteriophage treatment consisted of a single intramuscular injection of two different bacteriophage (10 x 9 pfu) administered immediately after the E. coli challenge. Mortality in the birds challenged with E. coli and untreated was 68%, and the bacteriophage and enrofloxacin treatments significantly decreased mortality to 15 and 3%, respectively. There was total protection in birds that received both the bacteriophage and enrofloxacin representing a significant synergy. The decrease in mortality with enrofloxacin (3%) was significantly better than the decrease in mortality with bacteriophage (15%). Airsaculitis lesion scores and lesion incidence in surviving birds were significantly less in the enrofloxacin treatment compared to the bacteriophage treatment. Both bacteriophage and enrofloxacin provided effective treatments of colibacillosis, and the synergy between these two treatments suggests that bacteriophage combined with antibiotic treatment has significant value.

Technical Abstract: A study was conducted to evaluate the therapeutic efficacy of bacteriophage and the antibiotic enrofloxacin individually and in combination to treat colibacillosis. The experimental design was a 2 x 2 x 2 factorial with 8 treatments and 4 replicate pens of 10 birds. The treatments were (1) control, (2) unchallenged birds treated with bacteriophage, (3) enrofloxacin, or the (4) combination; (5) birds challenged with E. coli; and birds challenged with E. coli and treated with either (6) bacteriophage, (7) enrofloxacin, or the (8) combination of bacteriophage and enrofloxacin. Birds in the E. coli challenged treatments were challenged at 7 d of age by injecting 10 x 4 cfu of E. coli into the thoracic air sac. The antibiotic treatment was initiated immediately after the birds were challenged and consisted of 50 ppm enrofloxacin in the drinking water for seven consecutive days. The bacteriophage treatment consisted of a single intramuscular injection of two different bacteriophage (10 x 9 pfu) administered immediately after the E. coli challenge. Mortality in the birds challenged with E. coli and untreated was 68%, and the bacteriophage and enrofloxacin treatments significantly decreased mortality to 15 and 3%, respectively. There was total protection in birds that received both the bacteriophage and enrofloxacin representing a significant synergy. The decrease in mortality with enrofloxacin (3%) was significantly better than the decrease in mortality with bacteriophage (15%). Airsaculitis lesion scores and lesion incidence in surviving birds were significantly less in the enrofloxacin treatment compared to the bacteriophage treatment. Both bacteriophage and enrofloxacin provided effective treatments of colibacillosis, and the synergy between these two treatments suggests that bacteriophage combined with antibiotic treatment has significant value.

Last Modified: 7/30/2014
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