Description, clinical impact and early outcome of S. maltophilia respiratory tract infections after lung transplantation, A retrospective observational study

Abstract

Background and research question

S. maltophilia infections are associated with significant morbidity and mortality. Little is known regarding its presentation, management, and outcome in lung transplant recipients.

Study design and Methods

This retrospective case control study reviewed S. maltophilia respiratory tract infection in lung transplant recipients (01/01/2011-31/01/2020) and described the clinical, microbiological and outcome characteristics matched with lung transplant recipients without respiratory tract infection.

Results and interpretation

We identified 63 S. maltophilia infections in lung transplant recipients. Among them none were colonized before transplantation. Infections occurred a median of 177 (IQR: 45- 681) days post transplantation. Fifty-four (85.7 %) patients received trimethoprim-sulfamethoxazole (400/80 mg three times a week) to prevent Pneumocystis jirovecii pneumonia (PJP). S. maltophilia strains were susceptible to trimethoprim-sulfamethoxazole, levofloxacin, minocycline and ceftazidime in respectively 85.7 %, 82.5 %, 96.8 % and 34.9 % of cases. Median duration of treatment was 9 days (IQR 7–11.5). Clinical and microbiological recurrence were observed in respectively 25.3 % and 39.7 % of cases. Combination therapy was not associated with a decrease in the risk of recurrence and did not prevent the emergence of resistance. S. maltophilia respiratory tract infection was associated with a decline in FEV-1 at one year.

Conclusion

S. maltophilia is an important cause of lower respiratory tract infection in lung transplant recipients. Trimethoprim-sulfamethoxazole use as prophylaxis for PJP doesn't prevent S. maltophilia infection among lung transplant recipients. Levofloxacin and trimethoprim-sulfamethoxazole appear to be the two molecules of choice for the treatment of these infections and new antibiotic strategies (cefiderocol, aztreonam/avibactam) are currently being evaluated for multi-resistant S. maltophilia infections.