Metabolic Footprint of Treponema phagedenis and Treponema pedis Reveals Potential Interaction Towards Community Succession and Pathogenesis in Bovine Digital Dermatitis

Bovine digital dermatitis (BDD) is a cattle infection causing hoof lesions and lameness, with treponemes as key pathogens. We analyzed the metabolic activity of <i>Treponema phagedenis</i> and <i>Treponema pedis</i> using gas chromatography-mass spectrometry for organic acids (OAs), amino acids (AAs), and fatty acids (FAs), and high-performance liquid chromatography for short-chain fatty acids (SCFAs). Key findings include a 61.5% reduction in pyruvic acid in <i>T. pedis</i> and 81.0% in <i>T. phagedenis</i>. 2-hydroxybutyric acid increased by 493.8% in <i>T. pedis</i>, while succinic acid increased by 31.3%, potentially supporting <i>T. phagedenis</i>. Among AAs, glycine was reduced by 97.4% in <i>T. pedis</i> but increased by 64.1% in <i>T. phagedenis</i>. Proline increased by 76.6% in <i>T. pedis</i> but decreased by 13.6% in <i>T. phagedenis</i>. Methionine and glutamic acid were competitively utilized, with methionine reduced by 41.8% in <i>T. pedis</i> and 11.9% in <i>T. phagedenis</i>. Both species showed significant utilization of palmitic acid (reduced by 82.8% in <i>T. pedis</i> and 87.2% in <i>T. phagedenis</i>). Butyric acid production increased by 620.2% in <i>T. phagedenis</i>, and propionic acid increased by 932.8% in <i>T. pedis</i> and 395.6% in <i>T. phagedenis</i>. These reveal metabolic interactions between the pathogens, contributing to disease progression and offering insights to BDD pathogenesis.