Cupriavius pauculus causing a respiratory tract infection in a post-kidney-transplant patient: A firstly described rare clinical case

Cupriavidus pauculus is a gram-negative aerobic bacillus usually isolated from bottled mineral water, water from ultrafiltration systems in hospital setting and medical devices. Infections in humans are rare but usually severe, with most described cases of bacteremia, pneumonia, meningitis and sepsis. We describe a rare case of a Cupriavidus pauculus infection in a post-kidney-transplant context. A 60-year-old man, with Chronic Kidney Disease due to chronic glomerulonephritis, initiated hemodialysis in 1991 and received a cadaveric-donor kidney transplant in 1997. The graft functioned until 2008, when he returned to hemodialysis. After 2 years, he transited to Peritoneal Dialysis because of vascular access failure. He remained on PD for 7 years and received a new kidney transplant in 2018 after Encapsulating Peritoneal Sclerosis (EPS). The graft never gained function, so he remained peritoneal-dialysis-dependent. A few days after transplantation, peritonitis ensued ( Enteroccocus faecium , Serratia marcescens ). Even after Tenckhoff catheter removal, the clinical condition deteriorated, with need for continuous hemodiafiltration. The diagnose of a cecum perforation was made followed by hemicolectomy. Due to persisting respiratory and abdominal infections despite antibiotic regimens, and no kidney graft function, nephrectomy of the graft was performed, suspending immunosuppressive drugs. Later, a Cupriavidus pauculus was isolated in sputum, confirmed in two samples. Bacterial examination of the dialysis unit water system and equipment as well as of the ventilator used by the patient was negative. To our knowledge, this is the first case of a respiratory tract infection associated with Cupriavidus pauculus described in a post-kidney-transplant patient.