Prototheca wickerhamii as a cause of neuroinfection in a child with congenital hydrocephalus. First case of human protothecosis in Poland

Disseminated protothecosis: Case report and review of the literature

BACKGROUND

Human protothecosis is an uncommon infection caused by Prototheca spp that rarely infects humans.

AIM

Description of a rare disease and a review of its articles.

MATERIALS AND METHODS

We reported a 24-year-old man who presented with red-brown papules and plaques on the trunk's lateral side. We reviewed the literature about disseminated protothecosis and reported our experience with a patient with protothecosis between 2021 and 2023.

RESULTS

Overall, 54 cases of disseminated protothecosis were evaluated, 39 were due to P. wickerhamii, 12 were due to P. zopfii (22.2%), and three were due to Prototheca spp. We found that males were more affected (37 cases, 68.5%) than females (16 cases, 29.6%). The mean age of patients was 39.53 ± 22.48 years. However, disseminated protothecosis can affect people of any age (1-80 years). In contrast to P. wickerhamii, which causes blood, skin, brain, and gastrointestinal tract infections, P. zopfii was mainly found in the blood (7/22) and did not have a significant difference in the mortality rate (P = 0.11).

DISCUSSION

Disseminated protothecosis is a rare disease in immunocompromised patients but is generally rarer in immunocompetent hosts. Several underlying disorders include immunocompromised patients, prolonged application of steroids, diabetes mellitus, malignancies, organ transplantation, AIDS, and surgeries. Amphotericin B has been the most effective agent for protothecosis and is reserved for visceral and disseminated infections. Regarding localized cutaneous types, excision or surgical debridement is used.

CONCLUSION

Mulberry's appearance and appropriate cultural environments are helpful in diagnosing it.

Prototheca wickerhamii breast implant infection after reconstructive surgery: a new level of complexity

We report the first published case of Prototheca wickerhamii breast implant infection. This occurred after mastectomy, chemotherapy, radiotherapy, breast reconstruction, implant revisions and breast seroma aspirations and was preceded by polymicrobial infection. Definitive treatment required implant removal and intravenous liposomal amphotericin B. The management of breast prosthesis infections is discussed.

Cutaneous Protothecosis with Meningitis Due to Prototheca wickerhamii in an Immunocompetent Teenager: Case Report and Literature Review

Human protothecosis is a rare infection caused by Prototheca spp., which are environmental achloric algae ubiquitously existing in nature. Members of the genus of Prototheca usually cause localized infection that affects the skin or wounds. Systemic infection is extremely rare and tends to occur in immunocompromised patients. Here, we report a case of cutaneous protothecosis and meningitis due to Prototheca wickerhamii in an immunocompetent teenager who obtained full-body tattoos at the time of infection. To the best of our knowledge, this is the first description of P. wickerhamii isolated from both skin tissue and cerebrospinal fluid. The data contained in this report will increase our understanding of this pathogen and elucidate the most optimal treatment.

Cerebral protothecosis mimicking high-grade glioma

Prototheca wickerhamii is a common, indolent alga that seldom causes central nervous system infections in humans. We report the first UK case of cerebral protothecosis in an immunocompetent 56-year-old woman who presented with a 5-month history of intermittent fatigue followed by a 2-week history of symptoms, including right arm and leg weakness, a loss of fine motor coordination, worsening gait, right facial tingling, diplopia and a metallic oral taste. MRI scans revealed a multifocal abnormality suggestive of high-grade glioma. Given the clinical presentation, absence of immunodeficiency and characteristic MRI features, a diagnosis of high-grade glioma was deemed most likely by the multidisciplinary team. Surgical biopsy provided material for histopathological and microbiological diagnosis. She underwent a 2-year course of antimicrobials with surveillance MRI scans. The patient made a good functional recovery but still retains mild neurological sequelae.

Case Report: Olecranon Bursitis due to Prototheca wickerhamii in an Immunocompromised Patient

Human protothecosis is a rare algal infection caused by Prototheca; it is a ubiquitous achlorophyllic alga, which rarely causes human disease. Currently, the pathogenesis remains unclear and no treatment options have been elucidated. We present a case of olecranon bursitis caused by Prototheca wickerhamii in an immunocompromised patient. A 45-year-old man presented with left elbow pain after scraping his elbow on a tree. He reported significant pain and swelling of the elbow after injury, which resolved without intervention. He was diagnosed with HIV/AIDS infection and started on antiretroviral therapy. Afterward, he experienced recurrent elbow swelling and pain; an incision and drainage was performed and cultures demonstrated P. wickerhamii. Unsuccessful treatment with oral voriconazole led to an attempt at therapy with parental amphotericin and oral doxycycline; however the patient left against medical advice. He presented to our facility and both parental amphotericin and doxycycline were initiated with planned outpatient bursectomy. He clinically improved on that regimen but left against medical advice before completing his recommended course of IV amphotericin and oral doxycycline. Patients diagnosed with disseminated protothecosis can have a mortality rate upward of 67%. Given the rarity of this pathogen, no official treatment guidelines exist and there are few studies analyzing the antimicrobial susceptibility of Prototheca. Management is challenging because of slow-growing nature of the algae, paucity of research studies, and limited susceptibility of this pathogen. This case adds to the limited body of literature by demonstrating the clinical presentation of protothecosis and highlighting the pathology and current treatment options.

cytb as a New Genetic Marker for Differentiation of Prototheca Species

Achlorophyllous unicellular microalgae of the genus Prototheca (Trebouxiophyceae, Chlorophyta) are the only known plants that cause infections in both humans and animals, collectively referred to as protothecosis. Human protothecosis, most commonly manifested as cutaneous, articular, and disseminated disease, is primarily caused by Protothecawickerhamii, followed by Protothecazopfii and, sporadically, by Protothecacutis and Protothecamiyajii In veterinary medicine, however, P. zopfii is a major pathogen responsible for bovine mastitis, which is a predominant form of protothecal disease in animals. Historically, identification of Prototheca spp. has relied upon phenotypic criteria; these were later replaced by molecular typing schemes, including DNA sequencing. However, the molecular markers interrogated so far, mostly located in the ribosomal DNA (rDNA) cluster, do not provide sufficient discriminatory power to distinguish among all Prototheca spp. currently recognized. Our study is the first attempt to develop a fast, reliable, and specific molecular method allowing identification of all Prototheca spp. We propose the mitochondrial cytb gene as a new and robust marker for diagnostics and phylogenetic studies of the Prototheca algae. The cytb gene displayed important advantages over the rDNA markers. Not only did the cytb gene have the highest discriminatory capacity for resolving all Prototheca species, but it also performed best in terms of technical feasibility, understood as ease of amplification, sequencing, and multiple alignment analysis. Based on the species-specific polymorphisms in the partial cytb gene, we developed a fast and straightforward PCR-restriction fragment length polymorphism (RFLP) assay for identification and differentiation of all Prototheca species described so far. The newly proposed method is advocated to be a new gold standard in diagnostics of protothecal infections in human and animal populations.

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.

Clinicopathological features and course of cutaneous protothecosis

BACKGROUND

Protothecosis is an uncommon infection caused by the achlorophyllic algae found more commonly in tropical areas. Only a limited number of cases have been reported.

OBJECTIVE

We aimed to evaluate the clinicopathological features and treatment outcomes of cutaneous protothecosis.

METHODS

We retrospectively identified 20 pathology-confirmed cases of cutaneous protothecosis based on skin biopsies in two tertiary medical centres in Taiwan from 1997 to 2015.

RESULTS

The age of the patients at the time of diagnosis ranged from 48 to 85 years (mean age of 74 years). All lesions developed on the limbs. Twelve (60%) patients had adrenal insufficiency, but no patients had active malignancy at diagnosis. Interestingly, four (20%) patients had concurrent scabies infestation. Clinically, most lesions were erythematous plaques studded with punctate ulcers. Microscopically, the most common finding was granulomatous inflammation. Nineteen (95%) cases were successfully treated with itraconazole for 14-148 days with only one case of recurrence. Concomitant scabies should be suspected if pruritus is recalcitrant despite itraconazole treatment.

CONCLUSION

Despite its rarity, cutaneous protothecosis has become more significant due to an increased prevalence of immunocompromised individuals. Steroid overuse or iatrogenic adrenal insufficiency predisposes individuals to high-risk infections. Neglecting the disease leads to a chronic and incurable state. Protothecosis should be suspected in chronic eczematous and ulcerative plaques on the limbs refractory to conventional antibacterial and antiviral treatments, especially in patients with adrenal insufficiency. Clinical suspicion should be confirmed by skin biopsies, and confirmed cases can be successfully treated with itraconazole.

An optimized method for high quality DNA extraction from microalga Prototheca wickerhamii for genome sequencing

BACKGROUND

The complex cell wall structure of algae often precludes efficient extraction of their genetic material. The purpose of this study was to design a next-generation sequencing-suitable DNA isolation method for unicellular, achlorophyllous, yeast-like microalgae of the genus Prototheca, the only known plant pathogens of both humans and animals. The effectiveness of the newly proposed scheme was compared with five other, previously described methods, commonly used for DNA isolation from plants and/or yeasts, available either as laboratory-developed, in-house assays, based on liquid nitrogen grinding or different enzymatic digestion, or as commercially manufactured kits.

RESULTS

All five, previously described, isolation assays yielded DNA concentrations lower than those obtained with the new method, averaging 16.15 ± 25.39 vs 74.2 ± 0.56 ng/µL, respectively. The new method was also superior in terms of DNA purity, as measured by A260/A280 (-0.41 ± 4.26 vs 2.02 ± 0.03), and A260/A230 (1.20 ± 1.12 vs 1.97 ± 0.07) ratios. Only the liquid nitrogen-based method yielded DNA of comparable quantity (60.96 ± 0.16 ng/µL) and quality (A260/A280 = 2.08 ± 0.02; A260/A230 = 2.23 ± 0.26). Still, the new method showed higher integrity, which was best illustrated upon electrophoretic analysis. Genomic DNA of Prototheca wickerhamii POL-1 strain isolated with the protocol herein proposed was successfully sequenced on the Illumina MiSeq platform.

CONCLUSIONS

A new method for DNA isolation from Prototheca algae is described. The method, whose protocol involves glass beads pulverization and cesium chloride (CsCl) density gradient centrifugation, was demonstrated superior over the other common assays in terms of DNA quantity and quality. The method is also the first to offer the possibility of preparation of DNA template suitable for whole genome sequencing of Prototheca spp.

Chronic Eosinophilic Meningoencephalitis by Prototheca Wickerhamii in an Immunocompetent Boy

Human protothecosis is mainly a cutaneous infection caused by the Prototheca species. Prototheca wickerhamii is an established pathogen of eosinophilic meningoencephalitis in dogs, but no eosinophilic pleocytosis of the cerebrospinal fluid has been reported in human cases of meningitis. Herein, we report a case of chronic protothecosis manifesting eosinophilic meningoencephalitis in an immunocompetent boy.

Successful treatment of cutaneous protothecosis with liposomal amphotericin and oral itraconazole

Protothecosis is a rare algal infection, affecting primarily immunocompromised hosts. Optimal management is unclear: in-vitro antimicrobial breakpoints are not established and therapeutic decisions are primarily based on case reports. We present a case of cutaneous Prototheca wickerhamii infection in an immunosuppressed 63 year old male, successfully treated with liposomal amphotericin and prolonged itraconazole. Inoculation may have been through frequent hot-tub use, highlighting hot-tub exposure as an infection risk for the immunocompromised host.

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

Solid organ transplantation is an accepted therapy for end-stage diseases of the kidneys, liver, heart, and lungs. Unfortunately, transplantation is associated with infectious complications. Here, we present a case report of Prototheca wickerhamii olecranon bursitis and review all of the cases in solid organ transplant (SOT) recipients published in the literature to date. In our patient, the infection resolved with surgical therapy and limited antifungal therapy, and no symptoms have recurred over 24 months of follow-up. A review of the literature suggests that 50% of SOT recipients with Prototheca infection present with disseminated infection, and the overall mortality is 75%. More studies are required to determine the optimal management of protothecosis in this population.

Protothecal peritonitis in child after bone marrow transplantation: case report and literature review of paediatric cases

The case presented here illustrates a protothecal infection caused by Prototheca wickerhamii in a paediatric haematopoietic stem cell recipient followed by a review of the literature of all 13 paediatric cases published since 1980. Protothecosis is a rare disease caused by algae, not described in this setting before. Infection was proven additionally post-mortem from peritoneal dialysis fluid. Even though no death of a paediatric patient due to this infection has been reported and the mortality rate associated with protothecosis is low, our patient died from multiorgan failure as a result of numerous post-transplant complications and a strain of cultivated alga that was highly resistant to antifungal agents. Prototheca spp. show various susceptibility profiles, and there is no direct correlation between in vitro activity and clinical response. There are different treatment regimens described but there are no clear published guidelines of specific therapy of protothecosis. Paediatric cases were successfully treated mostly with amphotericin B and azoles. As the number of immunocompromised patients increases, it is necessary to think more about unusual pathogens such as Prototheca.

Ribosomal internal transcribed spacer of Prototheca wickerhamii has characteristic structure useful for identification and genotyping

Prototheca species are achlorophyllous algae ubiquitous in nature and known to cause localized and systemic infection both in humans and animals. Although identification of the Prototheca species in clinical specimens is a challenge, there are an increasing number of cases in which molecular techniques have successfully been used for diagnosis of protothecosis. In this study, we characterized nuclear ribosomal DNA (rDNA) of a strain of Prototheca (FL11-0001) isolated from a dermatitis patient in Japan for its species identification. When nuclear rDNA of FL11-0001 and that of various other Prototheca strains were compared by polymerase chain reaction (PCR), the results indicated that the sizes of ribosomal internal transcribed spacer (ITS) were different in a species-dependent manner, suggesting that the variation might be useful for differentiation of Prototheca spp. Especially, ITS of P. wickerhamii, the most common cause of human protothecosis, was distinctively larger than that of other Prototheca spp. FL11-0001, whose ITS was comparably large, could easily be identified as P. wickerhamii. The usefulness of the PCR analysis of ITS was also demonstrated by the discovery that one of the clinical isolates that had previously been designated as P. wickerhamii was likely a novel species. Furthermore, our data demonstrated that nucleotide sequences of P. wickerhamii ITS are heterogenous between different rDNA copies in each strain and also polymorphic between strains. Phylogenetic analysis suggested that the ITS sequences could be classified to four clades, based on which P. wickerhamii strains might be grouped into at least two genotypes. Comprehensive characterization of Prototheca rDNA may provide valuable insights into diagnosis and epidemiology of protothecosis, as well as evolution and taxonomy of Prototheca and related organisms.