In ovo Administration of Defined Lactic Acid Bacteria Previously Isolated From Adult Hens Induced Variations in the Cecae Microbiota Structure and Enterobacteriaceae Colonization on a Virulent Escherichia coli Horizontal Infection Model in Broiler Chickens

Abstract

The effects of <i>in ovo</i> administration of a defined lactic acid microbiota (LAM), previously isolated from adult hens, in the cecae microbiota structure and <i>Enterobacteriaceae</i> colonization after exposure to virulent <i>Escherichia coli</i> during the hatching phase of broiler chickens were evaluated. Embryos inoculated with LAM showed a significant (<i>P</i> < 0.05) reduction of <i>Enterobacteriaceae</i> colonization at day-of-hatch (DOH) and day (d) 7. Furthermore, there was a significant increase in total lactic acid bacteria on DOH, body weight (BW) DOH, BW d7, and d0-d7 BW gain and reduced mortality d0-d7 was observed in the LAM group compared with that in phosphate-buffered saline (PBS) control. The bacterial composition at the family level revealed that the <i>Enterobacteriaceae</i> was numerically reduced, whereas the <i>Ruminococcaceae</i> was significantly increased in the LAM group when compared with that in the PBS control. Moreover, the bacterial genera <i>Proteus</i> and <i>Butyricicoccus</i> and unidentified bacterial genera of family <i>Lachnospiraceae</i> and <i>Erysipelotrichaceae</i> were significantly enriched in the LAM group. In contrast, the <i>Clostridium</i> of the family <i>Peptostreptococcaceae</i> and unidentified genus of family <i>Enterobacteriaceae</i> were significantly abundant in the PBS control group. In summary, <i>in ovo</i> administration of a defined LAM isolated from adult hens did not affect hatchability, improved body weight gain and reduced mortality at d7, induced variations in the cecae microbiota structure and reduced <i>Enterobacteriaceae</i> colonization on a virulent <i>E. coli</i> horizontal infection model in broiler chickens.