Protothecal bursitis after simultaneous kidney/liver transplantation: a case report and review

Systemic protothecosis in an immunocompetent patient

BACKGROUND

Although uncommon, there is increasing interest and public health concerns of the pathogen Prototheca spp, a ubiquitous achlorophilic microalgae that can affect both humans and animals. High mortality rates have been reported in immunocompromised patients with disseminated infection, but no data is available in the immunocompetent population.

CASE PRESENTATION

We present the case of a 59-year-old man from rural area of Colombia who was admitted to the intensive care unit due to decompensated heart failure that was difficult to medically manage, with development of septic shock and isolation of Prototheca wickerhamii from blood culture. Fluconazole and Amphotericin B were given with successful outcome.

CONCLUSIONS

To date, protothecosis and its virulence factors and pathogenesis remain to be fully understood, in our case the isolation of this microalga and its implication of exacerbating chronic conditions such as heart failure is unclear. The medical-scientific community is invited to study this microorganism to determine effective management strategies, as well as its timely identification, treatment, and control, to avoid fatal outcomes.

Successful Treatment of the Gastrointestinal Manifestation of Prototheca in a Kidney Transplant Recipient: A Case Report

INTRODUCTION

The Prototheca species are achlorophyllic algae and they are recognized pathogens in animals. They have been reported to cause infections in humans; the majority of the infected patients are immunocompromised. Organ transplant recipients are at risk of infection caused by such unusual organisms.

THE CASE

Here we present a highly atypical case report of Prototheca mimicking a cecum tumor in a kidney recipient 7 years after the transplantation. Three years before this Prototheca infection, after a native nephrectomy, the patient underwent a complicated duodeno-jejunal reconstruction with feeding catheter jejunostomy. Imaging studies indicated a tumor-like space occupying lesion in the cecum. The patient was treated successfully with colon resection. Detailed histology excluded malignancy and proved Prototheca wickerhamii.

DISCUSSION

The pathogenesis and many biological aspects of human protothecosis are unclear. Usually, treatment involves both medical and surgical approaches. The surgical treatment should be complete excision. The literature suggests an extremely high mortality rate, and therefore we advocate aggressive surgery in organ transplant recipients. This case is the first report of a successfully treated gastrointestinal manifestation of protothecosis in an organ transplant recipient.

3-Bromopyruvate as an Alternative Option for the Treatment of Protothecosis

Protothecosis is an unusual infection of both humans and animals caused by opportunistically pathogenic microalgae of the genus Prototheca. Until now, no standardized treatment protocols exist for the protothecal disease, boosted by a remarkable resistance of Prototheca spp. to a wide array of antimicrobial agents currently available in clinical use. Consequently, there is an urgent need for new effective drugs against Prototheca algae. In this study, the anti-Prototheca activity of 3-bromopyruvate (3BP), either alone or in combination with amphotericin B (AMB) was assessed in vitro, as well as the cytotoxicity of 3BP toward the bovine mammary epithelial cells and murine skin fibroblasts. The mean minimum inhibitory concentrations (MIC) and minimum algaecidal concentrations (MAC) were 0.85 ± 0.21 and 2.25 ± 0.54 mM for Prototheca wickerhamii, 1.25 ± 0.47 and 4.8 ± 1.03 mM for Prototheca blaschkeae, and 1.55 ± 0.69 and 5.6 ± 1.3 mM for Prototheca zopfii gen. 2, respectively. For all Prototheca strains tested, a synergistic interaction between 3BP and AMB was observed, resulting in about 4-fold reduction of their individual MICs, when used together. The elevated content of intracellular glutathione (GSH) was associated with a decreased susceptibility to 3BP. Both epithelial and fibroblast cells retained high viability upon treatment with 3BP at concentrations equivalent to the highest MIC recorded (3 mM) and 10-fold higher (30 mM), with the mean cell viability exceeding 80%, essentially the same as for the untreated cells. The results from these in vitro studies emphasize the high activity of 3BP against the Prototheca algae, its synergistic effect when used in combination with AMB, and the safety of the drug toward the tested mammalian cells. Along with the advantageous physico-chemical and pharmacokinetic properties, 3BP may be considered an effective and safe novel agent against the protothecal disease.

Disseminated Protothecosis Caused by Prototheca zopfii in a Liver Transplant Recipient

Prototheca is a genus of achlorophyllic algae present ubiquitously in the environment. Human infections are rare affecting immunocompromised individuals. We report a case of fatal algaemia caused by Prototheca zopfii in a patient who underwent liver transplant. Tissue diagnosis is mandatory for diagnosing rare entities in seriously ill, immunocompromised individuals.