Intestinal Bacterial Community Dynamics in Three Commercial Broiler Breeds Using an Experimental Model of Necrotic Enteritis
Necrotic enteritis (NE) is an important enteric infectious disease caused by Clostridium perfringens which inflicts substantial economic losses in commercially-bred broilers worldwide. Recent studies suggest that C. perfringens infection of chickens disrupts the normal gut microflora (dysbiosis) that may contribute to the pathogenesis of NE. Therefore, the current study compared alterations in intestinal bacterial communities in three commercial breeds of broiler chickens that differ in susceptibility to experimental NE (Cobb, Ross, and Hubbard). Chickens were uninfected, or experimentally infected with C. perfringens or Eimeria maxima, either alone or in a co-infection disease model system, and 16S ribosomal RNA gene pyrosequencing was performed to identify and determine the relative abundance of gut bacteria. Firmicutes was the predominant phylum, and Lactobacillus was the most abundant genus, identified in all treatment groups. In general, the diversity of bacterial genera in these chicken breeds was reduced following single or double pathogen infections compared with uninfected controls. Further, differences were observed in the microbial community profiles at the genus and species levels among the different breeds, and when comparing uninfected vs. infected and C. perfringens or E. maxima single infections vs. C. perfringens/E. maxima co-infections. These results increase our understanding of the extent and nature of intestinal dysbiosis during experimental avian NE that may facilitate the development of new strategies to restore the normal gut microflora during field infections of commercial poultry flocks