The present invention discloses a Clostridium difficile lactate dehydrogenase comprising the amino acid sequence of SEQ ID NO: 2, or an amino acid sequence exhibiting at least 70, 80, 90, 95, 96, 97, 98, 99, or 99.5% identity with the amino acid sequence of SEQ ID NO: 2. A Clostridium difficile lactate dehydrogenase comprising the amino acid sequence of SEQ ID NO: 2. Also disclosed are nucleic acid sequences encoding same, vectors and host cells, antibodies against same, medicaments and methods of manufacture of a medicament for the treatment of a Clostridium difficile infection, and diagnostic test kits and diagnostic test methods for same.