Preoperative colonization and exposure to broad-spectrum antibiotics were found to be independent predictors of multidrug-resistant (MDR) and extended-spectrum β-lactamase Gram-negative (ESBL-GN) infections in patients who underwent bilateral lung transplantation, according to results of a retrospective observational study published in CHEST.
Researchers conducted a study among adult patients who underwent bilateral lung transplantation at a university hospital between February 2016 and December 2021. Patients were divided into 2 groups, with the first group comprising those who developed an MDR/ESBL-GN infection within 30 days after the procedure, and the second comprising those who did not develop the infection (controls). Patients who developed a postoperative infection received treatment on the basis of in-vitro susceptibility testing and in accordance with recommendations defined by the European Committee on Antimicrobial Susceptibility Testing. Univariable Cox proportional hazards regression was used to determine the association between patient characteristics and the time to MDR/ESBL-GN bacteria isolation following the procedure, and Cox proportional hazards regression was used to assess the relationship between MDR/ESBL-GN bacteria isolation and the risk of in-hospital mortality.
There were 132 patients included in the final analysis, of whom the median age was 52 (IQR, 41-60) years and 35% were women. Of these patients, 45 were in the MDR/ESBL group and 87 were in the control group.
Within the first 30 days following bilateral lung transplantation, ESBL and MDR-GN bacteria were isolated from 9 and 36 patients, respectively. Of these 45 patients, 27 developed an infection according to Sepsis-3 criteria and 18 experienced colonization. The most commonly isolated pathogens among patients in the MDR/ESBL group included Psuedomonas aeruginosa (49%) and Klebsiella pneumoniae (38%).
In terms of risk factors, patients in the MDR/ESBL group were younger (median age, 48 vs 57 years; P <.01) and had a lower BMI (median, 22 vs 24 kg/m2; P =.03) compared with those in the control group. The incidence of MDR/ESBL-GN infection was increased among patients who were vs were not colonized prior to the procedure (60% vs 22%), indicating preoperative colonization as an independent predictor of MDR/ESBL-GN bacteria isolation (hazard ratio [HR], 2.48; 95% CI, 1.04-5.90; P =.04). Prior exposure to empiric broad-spectrum antibiotic therapy also was found to be an independent predictor of MDR/ESBL-GN infection following bilateral lung transplantation (HR, 6.94; 95% CI, 2.93-16.46; P <.01).
In-hospital mortality occurred among 27% and 5% of patients in the MDR/ESBL and control groups, respectively. Analysis of Kaplan-Meier curves showed that the risk of in-hospital mortality was significantly increased among patients in whom MDR/ESBL bacteria were isolated vs those in the control group (HR, 6.38; 95% CI, 1.98-20.63; P <.01). Of note, the risk of in-hospital mortality did not differ between patients who developed MDR/ESBL-GN infection and those with preoperative colonization.
This study was limited by its retrospective design and its relatively short duration. In addition, the researchers did not assess the incidence of Gram-positive bacterial infections.
“The widespread use of rapid diagnostic assays for the detection of GN pathogens could be useful to identify [bilateral lung transplant] recipients at higher risk of developing severe infection, allowing [for] a more precise titration of antibiotics,” the researchers concluded.
Boscolo A, Sella N, Pettenuzzo T, et al. Multi-drug resistant and extended spectrum beta-lactamase Gram-negative bacteria in bilateral lung transplant recipients. Chest. Published online July 15, 2022. doi:10.1016/j.chest.2022.06.046