To test whether the prophylactic protective effect is limited to the MDR E. coli MDR1, we selected another MDR E. coli isolate (NRZ 21236; porin loss, ESBL), here referred to as MDR2, belonging to ST131, which is the most dominant ST linked to nosocomial infections caused by ESBL-carrying E. coli16,53. The gene discussed is VDAC1; the disease is nosocomial infection.