Lysine catabolism in Haemonchus contortus and Teladorsagia circumcincta

► Lysine is catabolised via saccharopine in adult worms and L3. ► In adults worms, but not L3, the pipecolate pathway is also functional. ► Piperideine-2-carboxylate reductase was not detected in the L3 of either parasite. ► Neither lysine dehydrogenase nor lysine decarboxylase activity was detected. ► LKR and SDH were dual co-factor enzymes, not specific for either NAD+ or NADP+.