Enterococcus cecorum is considered as an emerging pathogen in poultry and can cause substantial losses in broiler flocks, report researchers at the University of Veterinary Medicine Hannover in Germany.

In their paper in BMC Veterinary Research, Arne Jung and Silke Rautenschlein explain that femoral head necrosis and spondylitis were described as the main pathological changes in infected chickens. Nevertheless, they report, little is known about the pathogenesis of Enterococcus cecorum infection in broilers.

Their report shows for the first time the whole course of disease over an entire growing period including repeated necropsies and subsequent microbiological investigations.

In a flock of 18,200 broilers, a decrease in flock uniformity was detected from 14 days post hatch onwards with affected chickens showing lameness and an increase in flock mortality up to 7.2 per cent at day 33 post hatch.

In the first three weeks after hatching, pericarditis and hepatitis were found as the main pathological changes in 27.6 per cent and 9.8 per cent of the examined broilers, respectively.

Femoral head necrosis and vertebral osteomyelitis were detected in the last week of the growing period with 10.3 per cent and 2.3 per cent, respectively.

Heart, liver, spleen, yolk sac and vertebral column of 59 broilers with pathological changes were subjected to bacteriological analysis. Enterococcus cecorum was isolated from 23 birds (39 per cent), the first broiler was already positive at day 3 post hatch in the yolk sac. Additionally, 9.7 per cent of the broilers were rejected at the slaughterhouse primarily because of pathological changes.

The broiler cycle investigated had a much better footpad scorethan the seven cycles before and four cycles after the Enterococcus cecorum infection at the same farm.

Bacteraemia and generalised infection appear to be important steps in the pathogenesis of Enterococcus cecorum infection in broilers, concluded Jung and Rautenschleim.

They comment that this disease causes economic losses for the farmer not only due to an increase in flock mortality but probably also through substantially higher condemnation rates at the slaughterhouse.

The Hannover researchers speculated that the broilers were infected via the respiratory tract as this flock had lower footpad scores likely the result of drier litter. The latter may have led to higher dust concentrations and thus airborne Enterococcus cecorum.

Reference

Jung A. and S. Rautenschlein. 2014. Comprehensive report of an Enterococcus cecorum infection in a broiler flock in Northern Germany. BMC Veterinary Research. 10:311.

February 2015