Retrospective, monocentric observational pharmacological cohort study including all adult patients who underwent lung transplantation at IRCCS Azienda Ospedaliero-Universitaria di Bologna from 1st January 2002 to 31st August 2023.

Bacterial infections are clinically relevant complications in lung transplant recipients (LTRs) causing chronic lung allograft dysfunction and high rates of mortality, especially within the first year after transplant. Microorganisms responsible for infection can derive from the donor lung or pre-existing recipient flora. Indeed, even though native lungs are removed, colonization of the grafts from recipients colonizing strains often rapidly occurs.

Furthermore, grafts and preservation fluids are frequently infected or colonized with bacteria with a high transmissibility rate to LTRs.

The interpretation of bacterial growth from grafts and preservation fluids can be complex. While some experts recommend against using lungs that show growth of gram-negative bacteria, others permit their use if accompanied by targeted antibiotic therapy, citing retrospective studies that suggest similar overall survival rates for recipients of infected versus uninfected lungs. To prevent donor-derived infections, routine antibiotic prophylaxis is used. International guidelines recommendations are generic and predominantly based on cardiac procedures and no formal recommendations to guide antimicrobial selection in lung transplant (LT) surgery are currently available. Therefore, antibiotic regimens for perioperative prophylaxis are based on clinical judgment and knowledge of the local epidemiology, inducing heterogeneity in clinical practice between centers. In our Center, for the last 20 years, piperacillin/tazobactam plus levofloxacin has been the backbone of the antibiotic prophylaxis regimen for LTRs, according to internal guidelines.

This retrospective observational study aims to investigate the efficacy of piperacillin/tazobactam plus levofloxacin compared to piperacillin/tazobactam alone as antibiotic prophylactic regimens on preventing early bacterial infections and donor derived infection after LT and their possible impact on subsequent colonization by MDR organisms (MDRO). With the study, it will be possible to evaluate which of the two analyzed regimens is associated with a better outcome in the LTR cohort in terms of preventing early surgical site infections, covering the susceptibility of isolates from donor cultures, and influencing MDRO colonization. In this way, it will be possible to influence clinical practice in the center, improving the prognosis of patients undergoing LT. Finally, the data obtained from this study will contribute to increase the knowledge on prophylaxis regimens that can be adopted in hospitals with a similar epidemiological scenario.

Inclusion Criteria:

• Adult (age ≥ 18 years)
• Patients who underwent LT at IRCCS Azienda Ospedaliero-Universitaria di Bologna from 1st January 2002 to 31st August 2023
• Patients receiving peri-operative antibiotic prophylaxis according to internal guidelines at time of LT
• Signed informed consent

Exclusion Criteria:

• Lack of clinical and/or laboratory data regarding type of early bacterial infection and/or antibiotic prophylaxis received after lung transplant

All adult (≥ 18 years) patients who underwent Lung Transplant (LT) and received peri-operative antibiotic prophylaxis during the study period will be screened for inclusion. Patients are enrolled during follow-up visits within 5 months from the start of the study.