Effect of Salmonella Vaccine Strains on Broiler Chicken Cecal Microbiota

Introduction:  Vaccination is one of the more effective means for controlling Salmonella in poultry. The chicken ceca are fermentation chambers involved in polysaccharide digestion, water adsorption and urea recycling as well as possessing a wide range of indigenous microbial organisms. Although microbiota in the poultry ceca may play an important role in host health, a significant lack of knowledge exists regarding the effect of vaccine strains on normal microbiota in chicken ceca.

Purpose:  Evaluation of microbial composition changes in chicken cecal contents after vaccine administration to assess potential impacts of the Salmonella Typhimurium vaccine strains.

Methods:  The cecal microbial communities of unvaccinated (group A) and vaccinated chickens (group 2, vaccinated with P_BAD-mviN; group 3, vaccinated with wild type; group 4, vaccinated with DDmetRmetD) were compared through denaturing gradient gel electrophoresis (DGGE) and microbiome sequencing analysis.

Results:  Chickens from different treatment groups exhibited DGGE patterns that were indistinguishable from each other. However, microbiome sequencing analysis of individual chicken ceca revealed considerable changes in microbial composition by different vaccine strain treatments and detectable patterns of distinctive clustering among groups. The P_BAD-mviN Salmonella Typhimurium yielding the highest vaccine efficacy led to the most distinctive changes in the cecal microbiota.

Significance:  The present study provides comprehensive information about the impact of vaccine strains which can effectively control Salmonella Typhimurium in poultry on the microbiota of host and it may contribute to better understanding of vaccine strain effects.