To investigate the clinical and etiological characteristics of Klebsiella pneumoniae (KP) infection in the recipients after liver transplantation.

Clinical data of 54 patients infected with KP after liver transplantation in Lingnan Hospital, the Third Affiliated Hospital of Sun Yat-sen University from January 2015 to December 2018 were retrospectively analyzed. Among them, 48 patients were male and 6 female, aged from 7 months to 75 years with a median age of 54 years. The incidence, distribution and drug resistance of KP infection were analyzed. The expression levels of common carbapenemase genes (blaIMP, blaKPC, etc.) and β-lactamase gene (blaSHV) carried by 33 strains of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolated in 2018 were quantitatively measured by PCR.

A total of 699 cases of liver transplantation were performed in the same period. The KP infection rate was 7.7%(54/699), of which CRKP infection rate was 5.2%(36/699). The KP and CRKP infection rates increased year by year. The KP infection rate reached the peak at 9.7% in 2018, and the CRKP infection rate peaked at 7.7% in 2017. Approximately 80% and 81% of KP and CRKP infection occurred within postoperative 30 d.78 KP strains were mainly derived from respiratory tract, followed by abdominal cavity and blood. The detection rate of KP in multiple sites increased year by year. Drug sensitivity analysis demonstrated that the drug resistance rate of KP to penicillins, cephalosporins, carbapenems and quinolones elevated year by year, reaching the peak in 2017. The drug resistance rate towards aminoglycosides and aztreonam was the highest in 2017, and the drug resistance rate to compound sulfamethoxazole and tetracycline reached the peak in 2016. Drug resistance gene detection revealed that 16 of 33 CRKP strains carried blaKPC gene and 3 CRKP strains carried blaIMP gene.

KP infection primarily occurs in the respiratory tract of the recipients undergoing liver transplantation, which is prevalent in the early stage with an increasing tendency of multiple-site infection. The proportion of CRKP infection may increased. The main mechanism underlying drug resistance is producing carbapenemase. Comprehensive prevention and treatments and rational use of medicine should be carried out early in clinical practice.