Effect of infection with Eimeria tenella upon the cecal bacterial population in monoflora chickens.

Monoflora chickens were established at 2 days of age by an oral inoculation with one of six species of bacteria (Lactobacillus acidophilus, Bifidobacterium thermophilum, Bacteroides vulgatus, Clostridium perfringens, Escherichia coli, or Streptococcus faecalis) and were infected with Eimeria tenella (5 X 10(4) oocysts per bird) 2 days later. There were two experimental groups for each bacterium: birds infected with bacteria alone and birds infected with a combination of bacteria and E. tenella. Seven days after E. tenella infection, counts of B. thermophilum in the cecal contents were significantly lower for E. tenella-infected birds than for those infected by B. thermophilum alone, whereas 10 days after E. tenella infection, counts were higher for E. tennella-infected birds. The population of L. acidophilus in the cecal contents of the E. tenella-infected chickens 10 days after inoculation was significantly greater than that in uninfected chickens. No significant differences were observed between the numbers of B. vulgatus, C. perfringens, and S. faecalis in cecal contents of groups with and without E. tenella infections.