Streptococcus agalactiae: A rare peritoneal infection in a continuous ambulatory peritoneal dialysis patient

Abstract

Streptococcus agalactiae causes a rare and often fatal peritonitis in continuous ambulatory peritoneal dialysis (CAPD). A 52-year-old white female with Alport and chronic kidney disease was initiated on CAPD treatment. Nineteen months later she had a S. agalactiae peritonitis identified and received initially gentamicin–cephalothin, which was changed to ceftazidime, tobramycin, and vancomycin. Recovery started after peritoneal catheter removal. After 3 weeks, severe leucopenia occurred. Granulokine and steroids were given. Six weeks later, she felt well and an abdominal video laparoscopic procedure disclosed a diffuse peritoneal fibrosis, precluding CAPD resumption. She is now doing well on hemodialysis (HD).

Keywords:

• CAPD
• hemodialysis
• Streptococcus agalactiae peritonitis

CASE REPORT

The patient is a 52-year-old white female, architect, aware of having Alport syndrome for many years, with deafness and advanced chronic kidney disease (CKD). Stage V CKD was clinically recognized in March 2008. A peritoneal dialysis catheter was inserted and CAPD initiated. Patient did well until October 2009, when she complained of severe and diffuse abdominal pain. Physical examination disclosed an apparently healthy woman, blood pressure 110/80 mmHg, heart rate 120 bpm, and axillary temperature 36.8°C. Cardiopulmonary examination disclosed no abnormalities. Abdominal distention was observed with no other apparent changes. An ultrasound was performed and disclosed no remarkable findings. The peritoneal fluid aspect was initially clear and the number of leukocytes within normal limits. The following day, at the outpatient clinic, she presented with pain and a cloudy dialysis effluent was seen, with increased peritoneal leukocytes count: 1500 cells/mm³ with 92% neutrophiles, maintaining a similar pattern for almost 5 days. Peritonitis was diagnosed and gentamicin 40 mg/day intra-peritoneal (IP) plus cephalothin 1 g IP/day initiated. A Streptococcus agalactiae infection was diagnosed based on the peritoneal dialysis culture. Blood cultures were negative. After the fifth day of the previous regimen, antibiotics were changed to ceftazidime 1 g IP once a day, tobramycin 75 mg IP once a day, and vancomycin 1 g IV every 5 days. Patient persisted with abdominal pain, started with fever, and the peritoneal dialysis catheter was removed. A double lumen subclavian catheter was placed to start hemodialysis (HD).

Three weeks after the new antibiotic regimen was initiated, she presented with severe leucopenia – 900 leukocytes/mL – with a concomitant worsening anemia. Antibiotics and other drugs were discontinued. Granulokine 300 mcg IV/day, a 3-day course of methyl-prednisone 500 mg IV and subsequently PO prednisone 60 mg/day for 2 weeks were used. She refused to receive blood transfusions and erythropoietin dose was augmented to 8000 units IV thrice weekly and 4000 every other day subcutaneously. A bone marrow biopsy demonstrated diffuse hypocellular areas, representing all the lineages, with no evidences of neoplasia or granulomas. Forty days after admission, the patient was discharged from the hospital. One month later, she was submitted to a video laparoscopic procedure which showed a severe and diffuse inflammatory fibrosis, impeding CAPD treatment continuation. Patient has been on HD since then, for 4 h three times per week, feeling asymptomatic.

DISCUSSION

S. agalactiae may be present in the normal female genital flora and 9% to nearly 30% – mean 18.6% – of pregnant women are usually colonized in the vaginal or rectal area.¹ The three main causes of serious infection associated with S. agalactiae in the age of this patient are diabetes mellitus, heart disease, and malignancy. Peritoneal infection by this microorganism in CAPD patients has been scarcely reported^2–4 and the disease severity and high mortality rate have been particularly attributed to the frequent episodes of bacteremia and septic shock induced by this bacteria.^5–8 Death occurs in about 40% of the cases, particularly associated with risk factors such as pregnancy, diabetes, hypertension, and renal failure.^2,5 However, it was described a fatal S. agalactiae peritonitis in CAPD, being emphasized the absence of those predisposing factors, excepting renal failure.⁸ The herein reported patient also had no previous risk factors detected – apart from CKD – and survived. Indeed, the disease severity might justify that every woman on CAPD should undergo a gynecological evaluation to detect the presence of bacteria ensuing a prophylactic treatment. Diagnosis of the disease has been made in the laboratory basically through bag fluid cultures.

The decision to discontinue gentamicin–cephalothin and treat with the combination of ceftazidime, tobramycin, and vancomycin for at least 14 days was based on a reported suggestion that these drugs might diminish morbidity and mortality in CAPD patients.³ Despite S. agalactiae had been reported to be very sensitive to penicillin, this drug must be avoided in patients with CKDs because of its possibility of inducing neurotoxicity, including seizures.⁹

Severe leucopenia occurred probably as a complication of infection and of the combined antibiotic therapy use, particularly because of vancomycin.¹⁰ Also, as a consequence of the extremely serious infection, important anemia occurred, improving with antibiotics treatment and increased erythropoietin dose.

The video laparoscopic procedure demonstrated a very severe and diffuse inflammatory fibrosis, imposing severe restrictions on CAPD treatment continuation.

Data would suggest that early removal of the peritoneal catheter – as soon as S. agalactiae peritoneal infection is confirmed – must be performed trying to avoid, or at least to reduce, further serious clinical complications.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.