Surgical site infection after liver transplantation in the era of multidrug-resistant bacteria: what new risks should be considered?

Surgical site infection (SSI) is a frequent infection site after liver transplantation (LT), and multidrug-resistant bacteria are common agents of those infections. This study aimed to analyze risk factors for SSI, including SSI caused by a multidrug-resistant microorganism (MDRO) after LT. We performed a cohort study of patients who underwent an LT from 2010 to 2018. The outcomes were SSI and SSI caused by MDRO. We analyzed features related to surgical procedure, patients' characteristics, and post-LT intercurrence. Surveillance for carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant Enterococcus (VRE), and carbapenem-resistant Acinetobacter baumannii (CRAB) was performed through rectal swab at the LT admission and weekly until hospital discharge during all study periods. SSI was identified in 30.1% (229/762) of LTs. We observed a decline in the SSI rate from 37.5% in 2014 to 16.7% in 2018 (P 0.02). SSI caused by MDRO occurred in 109 (14.3%) patients. Klebsiella pneumoniae was the most common agent of both SSI and SSI caused by MDRO. The pre-LT colonization was 98 (12.9%) by CRE, 73 (9.6%) by VRE, and 28 (3.7%) by CRAB. Risk factors for SSI caused by MDRO identified were dialysis after LT (P 0.01), CRAB acquisition before LT (0.03), and CRE acquisition before LT (P 0.004); use of adjusted prophylaxis by MDRO risk was the only protective factor identified (P 0.01). MDROs were frequent agents of SSI after LT, and the carbapenem-resistant Gram-negative colonization before LT increased the risk of SSI by these agents.