Effect of a Commercial Competitive Exclusion Culture on Reduction of Colonization of an Antibiotic-Resistant Pathogenic Escherichia coli in Day-Old Broiler Chickens

Abstract

One-day-of-age broiler chickens were administered a commercial competitive exclusion (CE) product and then challenged by three different methods with an Escherichia coli O78:K80 that was pathogenic for poultry and resistant to six antibiotics. Three challenge methods were used on 2-day-old broilers: direct challenge, precolonized seeder, and instant seeder. Direct challenge was accomplished by administering the challenge E. coli per os. The precolonized seeder challenge had two chicks that had received the challenge E. coli 24 hr previously, whereas the instant seeder challenge had two chicks given the challenge E. coli per os with immediate placement with the experimental birds. One oral dose of the commercial CE product significantly reduced the colonization of the small intestine, large intestine, and ceca by the highly antimicrobial resistant poultry pathogenic E. coli O78:K80 at 7 and 14 days postchallenge by all three challenge methods. The overall mean reductions in colonization were 3.0 log10 for the large intestine, 3.0 log10 for the small intestine, and 4.0 log10 for the cecum. The most severe challenge method, on the basis of the least amount of reduction of colonization of the challenge E. coli by the CE, was by the direct oral gavage at 2 days of age.

Competitive Exclusion Reduces Transmission and Excretion of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Broilers

“…Although different animal trials (with Broilact versus Aviguard, 5 versus 14 days of follow-up, and various challenge strains) were set up, our results are in line with the overall reduction in the amounts of E. coli (35,39) or ESBL-producing E. coli (34) observed in broilers treated by use of the competitive exclusion strategy. In our study, both transmission and excretion were calculated and shown to be reduced by competitive exclusion, whereas previous studies analyzed only E. coli colonization rates, which did not allow a direct comparison of different parameters.…”

“…This approach has proved to be effective in terms of limiting colonization of broilers with pathogenic E. coli strains (35,38,39) as well as Salmonella (40). Similar results were obtained in studies to control colonization with and shedding of different nonpathogenic ESC-resistant E. coli strains in the ceca of broilers (34).…”

“…Nuotio and colleagues have shown a substantial reduction in the levels of colonization of broiler ceca with ESBL-producing E. coli as a result of the use of the Broilact product in young broiler chickens (34). A reduction in the level of colonization with pathogenic E. coli bacteria was also demonstrated to be an effect of commercial CE culture administration in day-old broilers (35).…”

“…The aim of our study was to set up an in vivo broiler model to study ESC-resistant E. coli transmission and to analyze the role of competitive exclusion on preventing this transmission in broilers. Competitive exclusion by the Aviguard product was chosen as an intervention strategy on the basis of its ability to reduce the number of Salmonella and pathogenic E. coli challenge organisms in the cecal content of broiler chicks (35)(36)(37). Aviguard is a commercial freeze-dried fermentation product derived from healthy, pathogen-free birds (http://www.msd-animal-health.co.za/products/aviguard/ 020_product_details.aspx).…”

The Potential of Antibiotic Alternatives for Enriching Beneficial Microbiota in Litter

“…This allows environmental bacteria to play a larger role in seeding the intestinal tract of the commercial broiler chick [1,2]. Many commercial poultry companies use a built up litter system, meaning that the bacteria left in the litter from the resistance [20][21][22][23][24][25] and modulation of inflammation [26][27][28][29][30][31][32]. It is imperative that chicks receive autogenous pioneer colonizers to mediate the development of a healthy intestinal microbiome essential for optimal flock performance.…”