We found that incubation of phage SCNJ1-Y with CPS before infection of strain SCNJ1 significantly reduced the number of plaque-forming units (infection efficiency, 51.17% vs 100%, P = 0.0001) (Fig. 3E), indicating the added CPS competitively bound to the receptor-binding protein of CPS on the phage. The gene discussed is CAD; the disease is infection.