Microbiome characterization of commercial turkeys with cellulitis

Cellulitis in commercial turkeys has emerged as one of the leading causes of morbidity and mortality in the United States. According to the United States Animal Health Association industry survey, cellulitis ranks among the top 5 health issues for the turkey industry. It also represents a major cause of carcass condemnation at slaughter with significant economic losses for turkey producers. The main bacterial pathogens associated with the disease are Clostridium spp., avian pathogenic Escherichia coli, and Staphylococcus aureus. The aim of this study was to characterize the microbial community of birds with cellulitis and compare it to the microbial profile of healthy birds, to identify potential agents and routes of the infection. A total of 4 sample types including cecum, ileum, skin, and subcutaneous tissue (SBT) from 10 Nicholas turkeys (1) with cellulitis (Cell+ group), (2) without cellulitis (Cell− group), and (3) healthy birds (Control group) were collected between 16 and 18 weeks of age. Samples of Cell+ and Cell− groups were collected at one farm with a history of cellulitis, whereas samples of Control group were collected at a sister farm, with no history of cellulitis. The microbial profile of all samples was characterized by 16S metagenomics. The SBT microbiome of Cell+ samples was dominated by Clostridium sensu stricto with a relative abundance of 65.86% compared with 0.06% and 0.29% in the Cell− and Control groups, respectively. Ileal microbiome of Cell+ group was the second highest in abundance of Clostridium sensu stricto compared with Cell− and Control groups, with relative abundances of 31.27%, 0,09%, and 3.37%, respectively. STB and ileal microbiome from Cell+ group were dissimilar to Cell− and Control groups (P < 0.05). Through bacterial isolation, C. septicum and C. perfringens were isolated from SBT samples elucidating a potential synergistic effect in the development of the disease. Additionally, the high abundance of Clostridium spp. in the ileum and SBT provides insight on the potential translocation of Clostridium spp. from the intestine to subcutaneous breast tissue resulting in cellulitis.

Key Words: cellulitis, Clostridium spp., translocation, gut health.

Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.