Drug Resistance and Risk Factors for Acquisition of Gram-Negative Bacteria and Carbapenem-Resistant Organisms Among Liver Transplant Recipients

Introduction Infections caused by Gram-negative bacteria, in particular carbapenem-resistant organisms (CRO), pose a great threat to liver transplant (LT) recipients. Understanding the risk factors for Gram-negative and CRO infections and the drug resistance of corresponding bacteria will help guide the prevention and treatment of these infections. Methods Data on the composition, distribution and drug resistance of Gram-negative bacteria and CRO among LT recipients were collected. The risk factors for Gram-negative and CRO infections were identified via univariate and multivariate analysis. Results A total of 45 episodes of Gram-negative infection, including 20 episodes of CRO infection, occurred in 19.9% (27/136) of LT recipients. Klebsiella pneumoniae was the dominant pathogenic bacteria (14/45; 31.1%). The most common site of infection was the abdominal cavity/bile duct (11/27; 40.7%). Eleven (8.1%) patients died within 2 months after LT, and two deaths were related to Gram-negative infection. Gram-negative bacteria were relatively sensitive to tigecycline and polymyxin B, with resistance of 26.7 and 11.1%, respectively. CRO had lower resistance to ceftazidime/avibactam (45.5%) and polymyxin B (10%). A univariate analysis showed that male sex, infection within 2 months prior to LT, duration of surgery >= 400 min, reoperation, indwelling urethral catheter use >= 3 days and elevated alanine aminotransferase on day 1 post-LT were associated with Gram-negative infection. Multivariate logistic regression analysis revealed that infection within 2 months prior to LT [odds ratio (OR) = 4.426, 95%CI: 1.634-11.99, P = 0.003], duration of surgery >= 400 min [OR = 3.047, 95%CI: 1.194-7.773, P = 0.02] and indwelling urethral catheter use >= 3 days [OR = 5.728, 95%CI: 1.226-26.763, P = 0.026] were independent risk factors for Gram-negative infection after LT, and that only carbapenem use >= 3 days within 15 days prior to infection [OR = 14, 95%CI: 1.862-105.268, P = 0.01] was related to the occurrence of CRO infections. Conclusion The incidence of Gram-negative and CRO infections was high in the early post-LT period. The most common infection site was the abdominal cavity/bile duct, and the dominant pathogen was K. pneumoniae. Patients with infections within 2 months prior to LT, prolonged surgery time or delayed urethral catheter removal were prone to Gram-negative infection. Carbapenem exposure was correlated with CRO infections.