Blood infections area often catheter related. Peritoneal catheter infections usually present with abdominal pain and cloudy fluid.
I think, but I could be wrong, that being on dialysis is a risk.
With hemodialysis, its S. aureus, and to a lessor extent anything. Patients get colonized in the nose, which will precede bacteremia (nose has staph, nose is picked, finger then touches graft, then needle drags staph into the vascular space).
With CAPD it tends to be skin flora, especially coagulase negative Staphylococcus. But anything can sneak into the peritoneal space. We had one lady whose cat slept in her dialysis bag warmer. She got Pasteurella peritonitis. Really.
Weekly nasal mupirocin prevents staphylococcal aureus bacteremia in hemodialysis. As does a baby aspirin.
Lymphocyte assays are better than a skin test for diagnosing latent TB in dialysis patients, something to consider should the patient be heading towards a transplant (PubMed).
If you grow bowel flora in the peritoneal fluid of a CAPD patient, say, a Bacteroides or Escherichia coli or Enterococcus as examples, think of a bowel perforation. The catheter has eroded through bowel wall. Guaranteed.