Histomonas meleagridis and several bacteria as agents of infectious enterohepatitis in gnotobiotic turkeys

A dual etiology, involving a protozoan ( Histomonas meleagridis) and a single species of bacteria ( Escherichia coli, Clostridium perfringens, or Bacillus subtilis), has been demonstrated for infectious enterohepatitis, using gnotobiotic (“bacteria-free”) turkeys. Koch's postulates for suspected disease organisms have been applied to the combination of H. meleagridis and E. coli and each of the four postulates was fulfilled, indicating that this combination of organisms represented a true etiological pattern for infectious enterohepatitis of turkeys. Negative results for disease production were obained with H. meleagridis alone; H. meleagridis and Aerobacter cloacae + Streptococcus fecalis; or H. meleagridis and Proteus mirabilis, as inocula for gnotobiotic turkeys. Similarly, negative results were obtained from the administration of killed or filtered E. coli + viable H. meleagridis.