Logistic regression analysis showed that ICU occupancy time >7 days (OR = 3.431; 95%CI 1.251~4.152), beta-lactamase inhibitor antibiotics (OR = 3.018; 95%CI 1.102~5.394), carbapenem antibiotics (OR = 5.232; 95%CI 2.579~7.561) were independent risk factor for nosocomial infection of CRE (Table 7). The gene discussed is LACTB; the disease is nosocomial infection.