An Outbreak and Source Investigation of Enterococcal Spondylitis in Broilers Caused by Enterococcus cecorum

Abstract

Enterococcus cecorum was isolated from spondylitis lesions in broilers from two flocks in North Carolina that were experiencing increased mortality. Affected birds showed paresis and paralysis, clinical signs characteristic of enterococcal spondylitis (ES). Affected birds rested on their hocks and caudal abdomens with legs extended forward and were unable to stand or walk. Necropsy examination of affected birds revealed firm to hard inflammatory masses involving the vertebral bodies at the level of the free thoracic vertebra that bulged dorsally and compressed the spinal cord. When opened, lesions contained pale, tan to yellow caseonecrotic material. Microscopically, necrosis and fibrinoheterophilic spondylitis with intralesional gram-positive bacteria were seen. Heavy growth of E. cecorum recovered from vertebral lesions confirmed the diagnosis of ES. To investigate possible sources of the organism for one of the flocks bacterial cultures were made from the environment, water lines, mice trapped on the farm, cecal/cloacal swabs from one of the parent broiler breeder flocks, egg residue, hatching eggs, and the hatchery environment. Except for cecal/cloacal swabs from the breeders, E. cecorum was not isolated from any of these samples. When compared phenotypically and genotypically, cecal/cloacal isolates of E. cecorum from the breeders differed from isolates from spondylitis lesions in the broilers. The source of E. cecorum for the broiler flocks was not determined, but vertical transmission appears unlikely.

Enterococcal-related vertebral osteoarthritis in South African broiler breeders: A case report

“…Any immunosuppressive condition would naturally impair the ability to combat an opportunistic infection with E. cecorum, which is a normal intestinal commensal. Differences in pathogenicity between clinical and commensal intestinal isolates have also been proposed (Martin et al 2011;Robbins et al 2012;Stalker et al 2010), with evidence reported by Boerlin et al (2012) suggesting that the emergence of clones is more likely to cause opportunistic infections. It has been observed that the disease can persist in a site from one cycle to the next, implicating the environment as a source for such E. cecorum strains of varying virulence (De Herdt et al 2008;Kense & Landman 2011).…”

“…Early detection, differentiation from conditions with similar clinical signs and treatment are important to limit the losses incurred as a result of the disease. The ages of broiler breeders in recorded outbreaks range from 3-18 weeks (Armour et al 2011;De Herdt et al 2008;Robbins et al 2012), an age span that correlates with a period of rapid skeletal development in the birds. The highly vascularised nature of growth plates in rapidly growing bones, in particular, has been reported to leave such articulating bones susceptible to vascular trauma and bacterial infection during the resultant capillary bed expansion (Collett 2013;Wiseman & Prisby 2013).…”

“…The exact origin, predisposing factors, and pathogenesis of enterococcal-associated vertebral osteoarthritis (EVOA) are still largely unknown (Kense & Landman 2011;Robbins et al 2012). Currently, however, the most widely accepted theory is that E. cecorum, which is normally present in the gut, enters the blood stream via a compromised intestinal barrier (Martin, Martin & Barnes 2011;Stalker et al 2010).…”

“…They showed clinical signs of lameness and died as a result of starvation and dehydration. Enterococcus cecorum is recognised as an emerging avian pathogen (Aziz & Barnes 2009;Robbins et al 2012) with significant economic consequences for the poultry industry.…”

Antimicrobial resistance in Enterococcus spp. isolated from laying hens of backyard poultry floks

“…Enterococci are involved also as etiological agents of infections in veterinary medicine, such as mastitis in cattle, diarrhea in swine and cattle, as well as endocarditis, septicemia, spondylitis, and amyloid arthropathy in poultry [7,8].…”