Fungal Peritonitis Caused by Rhodotorula mucilaginosa in a CAPD Patient Treated with Liposomal Amphotericin B: A Case Report and Literature Review

Comparative Analysis of Capsular and Secreted Polysaccharides Produced by Rhodotorula mucilaginosa and Cryptococcus neoformans

Fungal infections are a global public health challenge, especially among immunocompromised patients. Basidiomycetous yeasts, such as Rhodotorula mucilaginosa, have emerged as opportunistic pathogens, but have received less attention than Cryptococcus neoformans. This study aimed to characterize the polysaccharides of R. mucilaginosa and compare them with those of C. neoformans, analyzing their clinical implications. Comprehensive physicochemical, mechanical, and ultrastructural analyses of polysaccharides from both species were performed, revealing correlations with virulence and pathogenicity. R. mucilaginosa cells are surrounded by a capsule smaller than that produced by C. neoformans, but with similar polysaccharides. Those polysaccharides are also secreted by R. mucilaginosa. Cross-reactivity with R. mucilaginosa was observed in a diagnostic C. neoformans antigen test, using both in vitro and in vivo samples, highlighting the need for more reliable tests. Some R. mucilaginosa strains exhibited virulence comparable to that of C. neoformans in an invertebrate experimental model (Tenebrio molitor). This study contributes to a deeper understanding of yeast pathogenicity and virulence, highlighting the need for more accurate diagnostic tests to improve the differential diagnosis of infections caused by basidiomycetous yeasts.

Pleural empyema due to Rhodotorula mucilaginosa – a rare yet severe complication of a previously undiagnosed cancer patient

Rhodotorula mucilaginosa (R. mucilaginosa) has been increasingly recognized as an emerging opportunistic pathogen causing invasive fungal infection, mainly in immunosuppressed patients. We report the case of a previously undiagnosed lung cancer patient with a pleural empyema due to R. mucilaginosa.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.

Along came a spider: an unusual organism identified in a peritoneal dialysis patient, a case report and literature review

Background

Peritoneal dialysis-associated peritonitis can uncommonly be caused by fungal infections. When they do present, they are associated with significant mortality and morbidity. We describe a case where a sample of peritoneal dialysate fluid grew Rhodotorula muciliginosa, a yeast organism present in the normal environment which has previously been reported as rarely causing peritonitis. We believe this is the first case where the Rhodotorula spp. and its origin has been identified.

Case presentation

A 20 year old male grew Rhodotorula muciliginosa from his peritoneal dialysis fluid on three separate occasions when a fluid sample was sent following a disconnection and subsequent set change. He was not systemically unwell and his peritoneal dialysate was clear. As Rhodotorula spp. is exceedingly difficult to treat our patient had his Tenchkoff catheter removed. Subsequent samples of soil and sand from his bearded dragon and Chilean tarantula cases, kept in his bedroom where dialysis occurred, were tested. The tarantula sand was identified as the source of the Rhodotorula spp. Of note, Candida was isolated from sand from the bearded dragon case. Once his Tenchkoff was removed he was treated with an intravenous course of antifungal therapy. He has since had a new Tenchkoff catheter inserted and recommenced PD following education around pets and hygiene.

Conclusions

In this era where people are keeping increasingly rare and unusual wildlife in their homes, this case highlights the need for clinician and nursing staff awareness of a patient’s home environment and hobbies when they are undergoing peritoneal dialysis. Sand from our patient’s tarantula case grew the colonising organism but interestingly soil from his bearded dragon case also isolated candida. This can also cause difficult to treat peritonitis.

Microbiological and virulence aspects of Rhodotorula mucilaginosa

We aimed to characterize microbiologically clinical isolates of R. mucilaginosa isolated from colonization of a patient with chronic renal disease (CKD), as well as to evaluate their phylogeny, antifungal susceptibility, virulence, and pathogenicity in order to infer the potential to become a possible infective agent. For this study, two isolates of R. mucilaginosa from oral colonization of a CKD patient were isolated, identified and characterized by classical (genotypic and phenotypic) methods. Susceptibility to conventional antifungals was evaluated, followed by biofilm production, measured by different techniques (total biomass, metabolic activity, colony forming units and extracellular matrix quantification). Finally, the pathogenicity of yeast was evaluated by infection of Tenebrio molitor larvae. All isolates were resistant to azole and sensitive to polyenes and they were able to adhere and form biofilm on the abiotic surface of polystyrene. In general, similar profiles among isolates were observed over the observed periods (2, 24, 48 and 72 hours). Regarding extracellular matrix components of biofilms at different maturation ages, R. mucilaginosa was able to produce eDNA, eRNA, proteins, and polysaccharides that varied according to time and the strain. The death curve in vivo model showed a large reduction in the survival percentage of the larvae was observed in the first 24 hours, with only 40 % survival at the end of the evaluation. We infer that colonization of chronic renal patients by R. mucilaginosa offers a high risk of serious infection. And also emphasize that the correct identification of yeast is the main means for an efficient treatment.

Simultaneous Removal And Reinsertion of the PD Catheter in Relapsing Peritonitis

Background:Relapsing peritonitis in peritoneal dialysis (PD) is associated with lower cure rates and more hemodialysis (HD) transfers, as catheter removal is recommended in these situations. The aim of our study was to evaluate the continuation of PD without perioperative transfer to HD in patients who underwent a simultaneous catheter removal and replacement for relapsing peritonitis.Methods:This was a retrospective monocentric study. Patients with simultaneous catheter removal and replacement for relapsing peritonitis or peritonitis at high risk of relapse (fungal or Pseudomonas infection) between 1 January 2007 and 31 December 2016 were included. The events of interest were the continuation of PD without perioperative transfer to HD, postoperative complications, new infection with the same organism, and technique survival.Results:Of the 271 incident patients in PD during this period, 11 had a simultaneous catheter removal and replacement for relapsing peritonitis (8) or high risk of relapse peritonitis (3). Eight (72.7%) patients pursued PD without transfer to HD. Six infections were due to microorganisms other than gram-positive cocci. At 1 year, 7 (63.6%) of the 11 patients were still on PD. After the surgery, there were no peritonitis or catheter-related infections caused by the same organism.Conclusion:Simultaneous catheter removal and replacement for peritonitis appears to be an effective procedure for maintaining patients on PD.

Exserohilum Peritonitis in Peritoneal Dialysis in Northern China: A Case Report

Fungal peritonitis is a catastrophic complication of peritoneal dialysis (PD) and often requires termination of PD. It is usually caused by Candida species. Here we report a rare case of Exserohilum peritonitis. The patient was successfully treated with catheter removal and anti-fungal therapy.