Pannonibacter phragmitetus (P. phragmitetus) is an opportunistic, Gram-negative rod, facultative anaerobic, chemoorganotrophic, motile germ, which is rarely pathogenic in humans.1 It is used in bioreactors for the detoxification of heavy metals and polycyclic aromatic compounds. Infection by this germ represents a threat to immunosuppressed patients due to its resistance to multiple antibiotics. However, the pathogenesis and resistance mechanisms are still not fully understood.1 It was first found in human blood cultures (BCs) in 1975 in the United Kingdom. To date, only five cases of P. phragmitetus infection have been reported in humans: one case of prosthetic valve endocarditis;2 two cases of septicaemia;3 one case of recurrent septicaemia;4 and one case of liver abscess.5 We describe here the case of a patient with permanent haemodialysis catheter infection and bacteraemia secondary to P. phragmitetus.

This was a 61-year-old male patient from Cuba with a history of high blood pressure and penicillin allergy. He was referred to our clinic from primary care with impaired renal function (creatinine 6.67 mg/dl, CKD-EPI glomerular filtration rate 8 ml/min and urea 178 mg/dl) and anaemia (haemoglobin 9 g/dl). This was an incidental finding in a routine test the patient had after living here in Spain for five years. The immunological study was negative, and the kidneys showed signs of chronic damage on ultrasound. The patient was started on a haemodialysis programme in October 2018 through a permanent right jugular catheter, with a request made for creation of an arteriovenous fistula (AVF) as definitive vascular access. A month and a half after starting renal replacement therapy, the patient travelled to his native Cuba, where he continued to have his usual sessions. The first day he restarted haemodialysis in our unit, he developed a fever during the session, but general condition was not affected. No infectious focus was found in the respiratory, genitourinary or gastrointestinal systems, and there was no discharge or erythema on the skin at the catheter entry site. Blood tests showed: haemoglobin 11.2 g/dl; leucocytes 7560/mm3, with no left shift; and CRP of 6.3 mg/l. As vascular catheter infection was suspected, three blood cells culture (BCs) were obtained and empirical treatment was started with vancomycin and gentamicin. On the second day, we were informed of growth of P. phragmitetus in all three BCs. In view of these findings, the cultures were repeated and the germ isolation confirmed. The antibiogram showed the microorganism to be sensitive to imipenem, amikacin and ciprofloxacin; and it was resistant to piperacillin/tazobactam, ceftazidime, gentamicin, tobramycin and cotrimoxazole. After obtaining these results, vancomycin and gentamicin were discontinued and a new antibiotic therapy started with oral ciprofloxacin, with a very good clinical and analytical response resulting in negative BCs. An echocardiogram was also performed, which ruled out endocarditis. The patient did not require hospital admission. Three weeks later, the permanent catheter was removed as the AVF was successfully punctured. The patient has now had a kidney transplant and has had no further episodes of bacteraemia due to P. phragmitetus, despite being on immunosuppressive therapy.

The possibility of infections by unusual germs should be considered in patients who travel to developing countries. This is important in patients with permanent devices and who are immunosuppressed, such as people on haemodialysis or peritoneal dialysis, or kidney transplant recipients. The interest of this case lies in the fact that bacteraemia caused by this germ has not previously been described in patients on dialysis with a permanent catheter. The literature states that P. phragmitetus is resistant to multiple antibiotics. Our patient made very good progress after oral treatment with quinolones.