A Case of Persistent Candida Keyfr Bloodstream Infection in a Lung Transplant Recipient

A 67-year-old female underwent an en-bloc double lung transplantation for idiopathic pulmonary fibrosis. The post-transplant course was complicated by refractory septic shock. Despite empiric antimicrobial coverage with vancomycin, meropenem, micafungin, and posaconazole, she continued to require high-dose vasopressors and remained unable to wean from veno-venous extracorporeal membrane oxygenation (ECMO). Blood cultures were positive for Candida Kefyr (teleomorph: Kluyveromyces marxianus), the same organism that had been isolated from donor bronchoalveolar lavage cultures 5 days prior to transplant. Micafungin and posaconazole doses were increased, and intravenous (IV) liposomal amphotericin B was added. Within 2 days, her hemodynamics improved, allowing successful weaning from ECMO. However, repeat blood cultures demonstrated persistent candidemia. Chest computed tomography revealed pericardial and bilateral pleural effusions, suspicious for mediastinitis and empyema. Transesophageal echocardiography confirmed pericardial effusion but showed no vegetations. Chorioretinal lesions were noted bilaterally without vitritis. Micafungin and posaconazole were discontinued and IV voriconazole was started for eye penetration. Amphotericin B was continued for 4 weeks and voriconazole for 3 months. Repeat blood cultures showed clearance of fungemia, and ophthalmology eye exam showed no further signs of chorioretinitis. Donor-derived infections are a rare complication of solid organ transplantation, with fungal infections posing a unique challenge due to their high morbidity and mortality. To our knowledge, there are no documented cases in the literature of possible donor-derived C. kefyr leading to blood stream infection in the recipient. This case highlights the need for heightened clinical vigilance and prompt multidisciplinary management to mitigate the impact of post-transplant complications.