Vertebral osteomyelitis caused by Enterococcus faecalis in broiler chickens from southern Brazil

Abstract

Enterococcal spondylitis affects poultry and causes progressive lameness. This study reports what seems to be the first case of vertebral osteomyelitis caused by Enterococcus in broiler chickens in southern Brazil. We also conducted an experimental infection to evaluate microorganismal characteristics and pathogenicity in broiler chickens. We performed bacterial isolation, identification, and histopathology. The isolates were tested for their growth and survival capacity at different temperatures, pH values, and antimicrobial resistance profiles. The experiment infection was conducted with broiler breeders (n=9). Group 1 = negative control, Group 2 = challenged orally, Group 3 = challenged via air sac. The autopsy was performed on the 50th day of life (DOL). The report showed spondylitis and fusion of thoracic vertebra, accompanied by spinal cord compression, and femoral head necrosis. We used the isolates (n=17) to test their growth at 10°C and 45°C, survival capacity for up to 60° for 30 min, and growth under pH levels from four to 12. Higher resistance was observed against macrolides and quinolones. On experimental infections, all animals expressed signs of lameness and "sitting on the hocks". Enterococcus faecalis is the causal agent of enterococcal spondylitis in broilers in southern Brazil, which is an underreported and emerging pathological condition that requires attention.