Focus on Enterococcus cecorum: A growing challenge in broiler production

Originally, this bacterium is a commensal, gram-positive, facultative anaerobic of the intestinal flora. However since the early 2000s, bacterial strains belonging to this family have increasingly caused health problems in fast-growing broiler farms in Northern Europe. In France in 2017, Enterococcus cecorum was responsible for 6% of cases of locomotor disorders in broiler farms, compared to 14.8% in 2022.

Colonization of animals from the first days of life

Pathogenic Enterococcus cecorum colonize the intestine during the first days of life of chicks, unlike commensal Enterococcus cecorum, which appear from the third week of life. At this young age, the chick digestive system, which is immature and permeable, allows the pathogenic bacteria to enter the bloodstream by crossing the intestinal mucosa. The bacteria can then infect various organs such as the heart, liver, and skeleton.

Appearance of lameness and loss of locomotion in chickens

Regarding the skeleton, the increasingly rapid growth of broiler chickens leads to severe mechanical stress on the joints, resulting in bone lesions. Enterococcus cecorum bacteria will colonize these inflamed areas, causing lameness and paralysis, which will become apparent around 3 to 4 weeks of the chicken’s life, reducing mobility and access to feed and water. This loss of mobility results in a significant decrease in animal performance and a high mortality rate on the farm. The absence of Enterococcus cecorum in the genetics of slow-growing chickens indicates that the bacteria are opportunistic and require the initial presence of bone lesions to grow.

Curative treatment may not always be effective

The development cycle of bacteria makes treatment difficult. Affected chicks are contaminated as early as the first week of life, but symptoms do not appear until 3 to 4 weeks later, with paralyzed, amorphous animals and soaring mortality rates (over 10%).

To date, no molecule appears to be sufficiently effective as a bactericide. Amoxicillin is the most commonly used antibiotic, but the bacteria survive in bedding, and the number of cases increases as soon as the treatment is stopped. Pathogenic strains of Enterococcus are highly resistant in the environment, and the main vectors of contamination are the litter and droppings of sick chickens. To prevent recurrence, affected buildings must be thoroughly disinfected and cleaned before the next batch.

In the context of this major challenge for the sector, our R&D department is mobilized to provide concrete answers.  Please contact us for more information.