TEM assay of CrfP lytic S. suis serovar 2 ZY05719 cells. A ZY05719 diluted with PBS at the beginning of the experiment. B ZY05719 incubated with CrfP for 15 min. The cytoplasm of ZY05719 spilled over from the hole. C Cell wall degradation after incubation with CrfP for 30 min. The extrusion and loss of cytoplasmic contents were observed, and these effects only a cell wall “ghost”. D, E ZY05719 with no CrfP served as a negative control.