Impact of Bacteriophage-Supplemented Drinking Water on the Population in the Chicken Gut.

Among intestinal coliform microbes in the broiler gut, there are potentially pathogenic () that can cause avian colibacillosis. The treatment with antibiotics favors the selection of multidrug-resistant bacteria and an alternative to this treatment is urgently required. A chicken model of intestinal colonization with an apathogenic model strain of . was used to test if oral phage application can prevent or reduce the gut colonization of extraintestinal pathogenic variants in two individual experiments. The strain E28 was used as a model strain, which could be differentiated from other strains colonizing the broiler gut, and was susceptible to all cocktail phages applied. In the first trial, a mixture of six phages was continuously applied via drinking water. No reduction of the model strain E28 occurred, but phage replication could be demonstrated. In the second trial, the applied mixture was limited to the four phages, which showed highest efficacy in vitro. colonization was reduced in this trial, but again, no reduction of the strain E28 was observed. The results of the trials presented here can improve the understanding of the effect of phages on single strains in the multi-strain microbiota of the chicken gut.