Vilnius University Childrens Hospital Centre for Paediatrics Vilnius Lithuania Email: petras.kaltenis{at}mf.vu.lt
Sir,
Although peritonitis in patients with terminal renal failure treated with peritoneal dialysis is most often caused by common organisms, many cases of peritonitis due to unusual pathogens have also been reported. Here we present a case of peritonitis caused by one such uncommon organism, Agrobacterium tumefaciens, in a girl with Jeune syndrome and terminal renal failure (the case was presented by us elsewhere) [1]. From the age of 4 years, the patient was treated by continuous cyclic peritoneal dialysis (CCPD). No case of peritonitis developed over the 3 years on CCPD.
At the age of 7 years, the patient was referred to the University Hospital because of the worsened state of her health. Physical signs on the last admission were slight face oedema, distended abdomen, no diuresis, no changes at the PD catheter exit site; blood pressure 130/110 mmHg. Peripheral blood counts were unremarkable. Blood chemistry was: blood urea nitrogen (BUN) 24.1 mmol/l, creatinine 1257 µmol/l, phosphate 2.08 mmol/l, compensated metabolic acidosis. The PD programme and antihypertensive treatment were intensified accordingly. Some 10 days later, abdominal pain and fever appeared, the dialysate became cloudy with 825 leukocytes/µl and Gram-negative rods were visible on a stained smear. Peripheral blood analysis showed: white blood cells 13.8 x 109/l with neutrophilia (56.4 %), erythrocyte sedimentation rate (ESR) 40 mm/h, C-reactive protein (CRP) 155 mg/l. The dialysate culture yielded growth of A.tumefaciens (identified by BBL CrystalTM Identification Systems, Enteric/Nonfermenter ID Kit, Becton Dickinson) susceptible to amoxicillin clavulanate, ticarcillin clavulanate, ampicillin sulbactam and ciprofloxacin, and resistant to all aminoglycosides, cephalosporins and carbapenems tested. Treatment with ciprofloxacin intraperitoneally and ampicillin sulbactam intravenously resulted in a temporary decrease of dialysate leukocyte count; however, the dialysate did not become completely clear and a repeated dialysate culture showed the growth of the same organism. The PD was discontinued, a peritoneal catheter was removed and haemodialysis was introduced. Ciprofloxacin was given intravenously for 10 days. The patients state improved and she was discharged without any signs of bacterial infection.
A Medline search yielded only two publications on peritonitis caused by Agrobacterium sp. and only one of them in patients with end-stage renal disease maintained on chronic PD [2]. The two patients described initially responded to antibiotics, but later relapsed and required removal of the catheter.
Agrobacteria are Gram-negative rods widely distributed in the environment [3]. The names of the species A.tumefaciens and A.radiobacter are used interchangeably and are considered to be synonymous [3,4]. Infections caused by these organisms are often associated with the presence of plastic foreign bodies. The case observed by us confirmed that it was difficult to eliminate pathogens in the presence of indwelling devices, even with the use of the agents active in vitro. The antimicrobial susceptibility pattern of the strain isolated is of interest, because it was resistant to cephalosporins, aminoglycosides and carbapenems. A recent publication showed complete sensitivity to carbapenems, amikacin and ciprofloxacin [5].
Thus, peritonitis in patients on continuous PD can be caused by a wide range of opportunistic microorganisms, including Agrobacterium sp. The treatment should be based on the results of an individual susceptibility pattern; however, a cure can hardly be expected without removal of the peritoneal catheter.
Conflict of interest statement. None declared.
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