Enterococcus cecorum, an opportunistic poultry pathogen: deeper understanding for better farm control

Abstract

In less than 20 years, Enterococcus cecorum has become one of the major pathogens in broiler farms, distributed worldwide. This opportunistic bacterium is a commensal of the poultry gut, responsible for locomotor disorders that can lead to flock mortality. E. cecorum is a cause of poor animal welfare, increased use of antibiotics and economic losses. This review aims to establish a link between E. cecorum infections and the current physiological and molecular knowledge of the bacterium. Genomic analyses indicate that clinical isolates of E. cecorum are adapted to intestinal colonisation of chicks from the very first days of life. Conversely, commensal strains colonise the intestine later, at the earliest during the third week of life. The contamination routes of farms and the factors that could favour E. cecorum infection are most likely multiple: vertical and horizontal transmissions, zootechnical parameters, biosecurity practices and animal susceptibility. This review also presents a number of ideas under development to improve the control of E. cecorum on farms and prevent infections.