Mucosal competitive exclusion to diminish colonization of chickens by Campylobacter jejuni.

Mucosal competitive exclusion flora (MCE) and length of MCE culture storage were studied to determine their influence upon colonization of Campylobacter jejuni in chickens. Day-of-hatch broiler chicks, held in isolation units, were treated with MCE or were left untreated. Thirty to 48 h later, groups of chicks were challenged with serial dilutions of C. jejuni (Strain A74/C). Single challenge doses and treatments were administered to chickens within each isolation unit. After 5 d, chicks were killed and levels of the organism in cecal materials were enumerated. Effective MCE was held at -80 C in 15% glycerol for 3 to 9 mo, and efficacy in inhibiting C. jejuni colonization of fresh and stored MCE cultures was compared. Colonization dose-50% (CD50%; dose needed to colonize one-half of the challenged chicks) and colonization quotients (CQ; log10 colony-forming unit geometric means per gram cecal materials) were determined. Data indicated that in three of five trials a significant reduction (P < .02) in CQ was observed in groups of chicks provided fresh MCE as compared with the control groups. Generally, efficacy of MCE treatment decreased with storage of the cultures. This study defines methods for production of MCE and the advantages and limitations of MCE intervention for C. jejuni colonization in chickens.