A K. pneumoniae vaccine (Kleb-SRP) was prepared by purifying siderophore receptor and porin proteins from fermentation cultures of K. pneumonia. Subcutaneous vaccination of cows with Kleb-SRP before calving decreased the risk of Klebsiella and total coliform mastitis by 76.9% and 47.5%, respectively (Gorden et al., 2018). The gene discussed is UCN2; the disease is mastitis.