Protothecosis in the mucosa of the pharynx mimicking pharyngeal cancer in an immunocompetent individual: a case report.

BACKGROUND: Protothecosis is a rare infection in humans and animals caused by the achlorophyllic algae Prototheca species. More than half of the protothecosis cases are cutaneous infections, and most cases are observed in immunocompromised individuals. CASE PRESENTATION: We report a case of Prototheca wickerhamii infection in the mucosa of the pharynx in a 53-year-old immunocompetent woman with an incidentally found mass lesion at the left tongue base. Histopathological findings of the mass lesion suggested cryptococcosis, but P. wickerhamii was identified from the oropharynx scrape culture based on DNA sequencing. After surgical resection, fosfluconazole treatment was initiated, and subsequently, treatment was switched to topical amphotericin B. The residual mass lesion did not deteriorate during the 4-month antifungal treatment and 1-year observational period. CONCLUSIONS: Prototheca species can be easily misdiagnosed as yeasts because of their morphological and pathological similarities. Prototheca, in addition to Cryptococcus should be considered if slow-growing, large Gram-positive organisms are encountered. Lactophenol cotton blue staining of the colony helps distinguish these organisms. Further study is needed to determine the appropriate treatment according to the infection focus.

A novel TaqMan qPCR assay for rapid detection and quantification of pro-inflammatory microalgae Prototheca spp. in milk samples.

Animal or human protothecosis belongs to rather rare, endemic, pro-inflammatory infections. It is caused by achlorophyllous algae of the genus Prototheca. Especially, P. bovis (formerly P. zopfii genotype 2) is often inflected as a non-bacterial causative agent of dairy cattle mastitis. In this study, we present a multiplex real-time PCR (qPCR) system for rapid and exact Prototheca spp. detection and quantification. Limit of detection, diagnostic sensitivity, and specificity were determined. For the first time, specific sequences of AccD (encoding acetyl CoA reductase) for P. bovis, cox1 (encoding cytochrome C oxidase subunit 1) for P. wickerhamii, cytB (encoding cytochrome B) for P. blashkeae and atp6 (encoding transporting ATPase F0 subunit 6) for P. ciferrii (formerly P. zopfii genotype 1) were used for species identification and quantification together with 28S rRNA sequence detecting genus Prototheca. The developed qPCR assay was applied to 55 individual cow milk samples from a herd suspected of protothecosis, 41 bulk milk samples from different Czech farms, 16 boxed milk samples purchased in supermarkets and 21 environmental samples originating from a farm suspected of protothecosis. Our work thus offers the possibility to diagnose protothecosis in the samples, where bacterial mastitis is the most commonly presumed and thereby assisting adequate corrective measures to be taken.

In vitro algicidal effect of polypyrrole on Prototheca species isolates from bovine mastitisAlgicidal activity of polypyrrole on Prototheca spp.

Algae of the genus Prototheca are microorganisms involved in the occurrence of diseases in humans and animals. In bovine species, Prototheca spp. cause environmental mastitis, productive losses in dairy herds, mainly leading to the discard of infected cows. Currently, there are no effective anti-Prototheca spp. drugs to combat this infection. Thus, the search for an efficacious therapy for Prototheca spp. infections have become essential. Highly soluble polypyrrole (Ppy) is a molecule with known antimicrobial activity. This study aimed to characterize Prototheca spp. isolates from bovine mastitis as well as to evaluate the susceptibility profile and to verify the morphological alterations on Prototheca spp. isolates treated with Ppy. In this research, 36 Brazilian isolates of Prototheca spp. were characterized by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) assay for the mitochondrial cytB gene. Additionally, Ppy algicidal activity against these isolates of Prototheca spp. was assessed by minimal microbicidal concentration method in microplates. Further, scanning electron microscopy (SEM) was performed in order to verify the morphological alterations on Prototheca spp. isolates in response to Ppy. The isolates were characterized as belonging to Prototheca zopfii genotype 2 (35/36) and Prototheca blaschkeae (1/36). Ppy had an algicidal effect on all isolates tested at concentrations ranging from 15.625 µg ml-1 to 62.5 µg ml-1. SEM showed changes on planktonic and sessile P. zopfii, including a decrease of the number of cells with the presence of an amorphous substance involving the cells. The algicidal activity of Ppy suggests the therapeutic potential of this molecule in the prevention and treatment of Prototheca spp. in bovine mastitis.

Multiple cutaneous infections caused by Prototheca wickerhamii.

BACKGROUND: Prototheca species are a group of organisms ubiquitously existing in nature but have become a pathogenic threat to public health, which has aroused wide attention. Species identification and antifungal susceptibility have essential and valuable meanings to clinical diagnosis and treatment. METHODS: A case of an 84-year-old patient who had suffered from multiple cutaneous infections was reported. Tissue samples of the damaged skin were collected from the patient and used for microscopic examination and tissue culture. Staining methods, the VITEK system with YSD card and the molecular identification method based on partial mitochondrion-encoded cytochrome b (cytb) gene amplification and sequencing were used for species identification. Antifungal susceptibility testing was completed by using YeastOne plate. RESULTS: The patient had type II diabetes mellitus. Round, grape-like, and scattered morula forms were observed under the microscope in bright blue with lactophenol cotton blue staining and in green fluorescence with fungus fluorescence staining. Yeast-like colonies were grown on both the blood plates and the Sabouraud agar. P wichehamii was identified and presented resistance to three echinocandins, fluconazole, and 5-fluorocytosine, while was susceptible to amphotericin B, posaconazole, itraconazole, and voriconazole. CONCLUSION: Our result revealed that an old patient with diabetes mellitus might be a dangerous population of cutaneous protothecosis. It also highlighted the contribution to microbial methodology on the diagnosis and treatment of such rare fungus infection.

Emergence of Fungal-Like Organisms: Prototheca.

The genus Prototheca consists of achlorophyllic algae that are ubiquitous in the environment and animal intestines. However, this organism has forfeited its photosynthetic ability and switched to parasitism. In 1894, Krüger described two microorganisms isolated in Germany from mucous flux of Tilia and Ulmus spp., namely Prototheca moriformis and P. zopfii. Based on their yeast-like colony morphology, Krüger classified these organisms as fungi. The genus is now included within the class Trebouxiophyceae, order Chlorellales, and family Chlorellaceae. Historically, protothecosis and infections caused by green algae have been studied in the field of medical mycology. Prototheca spp. have been found to colonize human skin, fingernails, the respiratory tract, and digestive system. Although human infection by Prototheca is considered rare, an increase in infections has been noted among immunosuppressed patients, those on corticosteroid treatment, or both. Moreover, the first human outbreak of protothecal algaemia and sepsis was recently reported in a tertiary care chemotherapy oncology unit in 2018. Prototheca is also a causative pathogen of bovine disease. Prototheca zopfii and P. blaschkeae are associated with bovine mastitis, which causes a reduction in milk production and secretion of thin, watery milk containing white flakes. Economic losses are incurred either directly via reduced milk production and premature culling of affected animals or indirectly as a result of treatment and veterinary care expenses. Thus, knowledge of this fungal-like pathogen is essential in human and veterinary medicine. In this mini-review, I briefly introduce human and animal protothecoses.

Short communication: Occurrence and persistence of Prototheca zopfii in dairy herds of Korea.

Bovine mastitis caused by Prototheca has been reported globally, and its incidence is increasing in dairy herds. The present study aimed to investigate the occurrence of Prototheca and persistence of Prototheca zopfii strains in Korean dairy herds. A total of 187 (7.5%) P. zopfii strains were isolated from 2,508 quarter milk samples collected from 50 dairy farms throughout Korea from 2015 to 2017. Prototheca zopfii was isolated from one farm among the 50 farms over the 3-yr period. The P. zopfii isolates belonged to genotype 2. Overall, Prototheca-positive quarter milk samples showed high somatic cell counts with an average value of log 6.48 ± 6.54 cells/mL. Prototheca zopfii was found to be persistent in an infected farm over a 2-yr period. To the best of our knowledge, this is the first report on the presence and persistence of protothecal mastitis caused by P. zopfii genotype 2 in a Korean dairy herd. This disease leads to a significant increase in somatic cell counts in milk, which persists for more than 1 yr in the affected cow udder. These results suggest that P. zopfii could pose a serious risk to dairy herds. Thus, strict surveillance for protothecal mastitis is urgently needed and sanitary conditions regarding the environment and milk collection are essential because of the lack of effective treatment options.

A survey on the incidence of Prototheca mastitis in dairy herds in Lublin province, Poland.

Prototheca mastitis has recently become an emerging disease; although its incidence is increasing steadily, its epidemiology remains largely understudied. The aim of this work was to investigate the prevalence of Prototheca spp. in dairy cows and their environment in Lublin province, covering most of southeastern Poland. Between December 2015 and July 2016, a total of 172 milking cows from 10 dairy farms were inspected for mastitis using clinical examination and the California Mastitis Test (CMT). Quarter milk samples (QMS, n = 179) and body site swabs (n = 151) from CMT-positive cows were collected for microbiological culture. In addition, we evaluated QMS and body site swabs from 23 healthy cows, along with 91 environmental samples. Of 100 CMT-positive cows, 71 had at least one QMS positive for microbial growth. In 8 (11.3%) of these cows, originating from 7 dairy farms, Prototheca spp. were cultured. The average somatic cell count of the Prototheca-containing milk was 4.02 × 106 cells/mL compared with 0.13 × 106 cells/mL of the Prototheca-free milk (collected from control animals). No significant differences were observed between mastitis and control cows with respect to counts of total white blood cells, lymphocytes, neutrophils, and eosinophils. Half of the cows with Prototheca spp. in their milk did not yield the algae from other anatomical sites. Eight cows were negative for the presence of Prototheca spp. in their milk but positive for the algae in swabs from anatomical sites. Among the environmental sources that were positive for Prototheca growth were watering troughs, manure, feed, and mud. All (45) Prototheca isolates recovered in this study were subjected to species- and genotype-level molecular identification. All QMS and most of the animal swabs (90%) yielded Prototheca zopfii genotype (gen.) 2. Of the animal samples, P. zopfii gen. 1 and Prototheca blaschkeae were isolated only from feces and rectum. Environmental samples grew either P. zopfii gen. 2 (67%) or P. zopfii gen. 1 (33%). This study demonstrates that P. zopfii gen. 2 is the third most common pathogen of mastitis in cattle in southeast Poland, with an overall incidence of 4.6%. Finding Prototheca spp., including P. zopfii gen. 1 and 2 and P. blaschkeae, in stool and rectal swabs from healthy animals may suggest their role as nonpathogenic microflora of bovine gut.

Prototheca zopfii Colitis in Inherited CARD9 Deficiency.

Human protothecosis is a rare microalgae infection, and its dissemination typically occurs in immunocompromised individuals, but no specific immune defect has been reported. Here, we describe an 8-year-old daughter of a consanguineous union with abdominal pain and bloody diarrhea for 3 months who was found to have pancolitis with numerous microalgae identified as Prototheca zopfii. In the absence of a known immunodeficiency, exome sequencing was performed, which uncovered a novel recessive frameshift mutation in CARD9 (p.V261fs). This report highlights that CARD9 deficiency should be investigated in patients with unexplained systemic/visceral protothecosis and suggests a new mechanistic insight into anti-Prototheca immunity.

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.

Canadian National Dairy Study: Herd-level milk quality.

The objective of this study was to estimate Canadian national milk quality parameters and estimate the bulk tank milk (BTM) prevalence of 4 mastitis pathogens, Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis, and Prototheca spp., on Canadian dairy farms. A questionnaire was sent to all Canadian dairy producers. Of the 1,062 producers who completed the questionnaire, 374 producers from across the country were visited and milking hygiene was assessed. Farm-level milk quality data for all Canadian dairy producers was collected from the provincial marketing boards and combined with the questionnaire and farm visit data. In addition, a BTM sample was collected either during the farm visit or by the marketing board in November of 2015 and was tested for 4 major mastitis pathogens using the PathoProof Mastitis Major 4 PCR Assay (Thermo Fisher Scientific Inc., Waltham, MA). Apparent herd-level prevalence was 46% for S. aureus, 6% for Prototheca spp., 0% for M. bovis, and 0% for Strep. agalactiae. Due to the low prevalence of M. bovis and Strep. agalactiae and a lack of significant factors associated with farms testing positive for Prototheca spp., an association analysis could only be carried out for Staph. aureus-positive farms. Factors associated with Staph. aureus-positive farms were not fore-stripping cows before milking (odds ratio = 1.87), milking with a pipeline system (odds ratio = 2.21), and stall bases made of a rubberized surface (mats and mattresses), whereas protective factors were using blanket dry cow therapy (odds ratio = 0.49) and applying a tag or visible mark on cows known to have chronic mastitis infections (odds ratio = 0.45). The Canadian national production-weighted geometric mean somatic cell count was determined to be 208,000 cells/mL. This is the first national dairy study conducted in Canada. Participating farms had higher milk yield; were more likely to have a loose housing system, parlor, or automated milking system; and had lower weighted mean BTM somatic cell count than the national level. Sampling larger farms with better milk quality means the apparent prevalence of the 4 mastitis pathogens likely underestimates the true levels.

Short communication: Cold atmospheric plasma inactivation of Prototheca zopfii isolated from bovine milk.

Mastitis is a serious bovine diseases that can be caused by Prototheca zopfii, yeast-like algae belonging to the family Chlorellaceae. The substantial economic losses and health damage associated with bovine mastitis emphasize the need to develop effective strategies aimed at control of the infection. Unfortunately, P. zopfii is highly resistant to most common antibacterial and antifungal agents, as well as to heat treatment. We report here the first attempt to use cold atmospheric plasma to inactivate this pathogen. We studied 20 strains of P. zopfii isolated from milk samples taken from cows with clinical or subclinical mastitis. The studies confirmed the high level of resistance of P. zopfii to typical antifungal agents, such as voriconazole, fluconazole, amphotericin B, caspofungin, anidulafungin, and micafungin. In contrast, each of the strains revealed high susceptibility to cold atmospheric plasma, >2-fold higher compared with a reference strain of Candida albicans. The obtained results are promising and open up a new approach in the fight against P. zopfii.

A Case of Prototheca zopfii Genotype 1 Infection in a Dog (Canis lupus familiaris).

Protothecosis is a rare disease caused by environmental algae of the genus Prototheca. These are saprophytic, non-photosynthetic, aerobic, colorless algae that belong to the Chlorellaceae family. Seven different species have been described. Prototheca zopfii genotype 2 and P. wickerhamii are most commonly involved in pathogenic infections in humans and animals. The objective of this work is to describe, for the first time, a case of protothecosis caused by P. zopfii genotype 1 in a dog. The dog, a 4-year-old mix bred male, was presented to a veterinary clinic in Montevideo, Uruguay, with multiple skin nodules, one of which was excised by surgical biopsy. The sample was examined histologically and processed by PCR, DNA sequencing, and restriction fragments length polymorphisms for the detection and genotyping of P. zopfii. In addition, transmission electron microscopy and scanning electron microscopy were performed. Histology showed severe ulcerative granulomatous dermatitis and panniculitis with myriads of pleomorphic algae. Algal cells were 4-17 µm in size, with an amphophilic, 2-4-µm-thick wall frequently surrounded by a clear halo, contained flocculant material and a deeply basophilic nucleus, and internal septae with daughter cells (endospores) consistent with endosporulation. Ultrastructurally, algal cells/endospores at different stages of development were found within parasitophorous vacuoles in macrophages. Prototheca zopfii genotype 1 was identified by molecular testing, confirming the etiologic diagnosis of protothecosis.

The Effect of Some Natural Essential Oils Against Bovine Mastitis Caused by Prototheca zopfii Isolates In Vitro.

The aim of the study was to evaluate the effect of essential oils obtained from Thymus vulgaris L., Origanum vulgare L., Origanum majerana L., Mentha × piperita L. and Allium ursinum L. against Prototheca zopfii strains that cause inflammation of the udder (mastitis) in cows. The study was conducted on ten strains derived from milk samples. The microdilution method was used to determine the sensitivity of P. zopfii strains to the studied essential oils, and the disk diffusion method was used to determine the sensitivity to antifungal chemotherapeutics. The plates were incubated for 48 h at 37 °C under aerobic conditions. All strains of algae were sensitive to the essential oils marjoram, thyme and oregano and resistant to mint and garlic oils. MIC values ranged from 0.25 to 1 µl/ml. Marjoram oil demonstrated the greatest activity, and oregano oil the weakest. Among the antifungal agents tested, 90% of strains showed sensitivity to nystatin. One of the tested strains (71/IV) was resistant to all investigated antifungal agents. The tested essential oils are known to have anti-algae activity and can be used as natural agents for prophylaxis in animals, particularly in mastitis-affected cows.

Human Cutaneous Protothecosis: A Case Report and Review of Cases from Mainland China, Hong Kong, and Taiwan.

We present a case of cutaneous protothecosis caused by Prototheca wickerhamii infection. The patient was a 72-year-old man with hypoalbuminemia. He responded well to fluconazole treatment. We reviewed this case along with 17 other cases of cutaneous protothecosis reported from mainland China, Hong Kong, and Taiwan. Of the 18 cases, 7 each occurred in mainland China and Taiwan, and 4 occurred in Hong Kong. Thirteen cases were caused by P. wickerhamii (72.2%), and three were caused by P. zopfii (16.7%); in two cases, the species was not identified (11.1%). In all, 9 (50%) patients were immunocompromised, and 10 (55.5%) patients denied having a history of trauma. All patients presented with polymorphic skin lesions, and erythematous papules, plaques, or nodules was the most common presentation (15/18, 83.3%). Genotyping was performed in five cases, mostly by means of small subunit ribosomal DNA amplification (four cases). Susceptibility tests (6 patients) showed that P. wickerhamii was sensitive to amphotericin B and voriconazole but resistant to fluconazole or itraconazole. Treatment succeeded in 15 (83.3%) patients and failed in 3 (16.7%). Our data indicate that the number of cutaneous protothecosis cases is underestimated in China, and the skin lesions have some diagnostic value.

Prototheca blaschkeae subsp. brasiliensis subsp. nov., isolated from cow milk.

A strain of an achlorophyllic alga, named PR24T, was isolated from cow milk samples from the state of Minas Gerais, Brazil. Based on 18S rDNA, 28S rRNA, D1/D2 region of the LSU rDNA and SSU rRNA gene sequence similarities, this strain was found to be a member of the genus Prototheca and closely related to Protothecablaschkeae SAG2064T. However, the novel strain could easily be distinguished from recognized Prototheca species by internal transcribed spacer, species-specific PCR, single-strand conformation polymorphism-PCR analysis and phenotypic characteristics. The inability to grow in Sabouraud broth at pH 4.0 and the different cellular fatty acid composition clearly distinguished PR24T from the reference strain of P. blaschkeae. The combination of genotypic and phenotypic data indicates that strain PR24T represents a subspecies of P. blaschkeae, for which the name Prototheca blaschkeae subsp. brasiliensis subsp. nov. is proposed. The respective type strain is PR24T (=DSM 103592T=IHEM 26958T).

In vitro algicidal effect of guanidine on Prototheca zopfii genotype 2 strains isolated from clinical and subclinical bovine mastitis.

Prototheca species have increasingly been reported to be opportunistic pathogens that cause mastitis in dairy herds, and it poses an emergent problem because at present, there are no effective therapies for the treatment of protothecal mastitis. This study investigated the in vitro algicidal effect of guanidine on 75 Prototheca zopfii genotype 2 strains isolated from 75 cases of clinical and subclinical bovine mastitis. All strains were susceptible to guanidine in vitro with minimal algaecide concentrations ranging from 0·001 to 0·035%. Guanidine is known to have a high microbicidal effect and is considered to be a new generation microbicidal compound. It is not toxic to human mucous membranes and conjunctivas at low concentrations and has been used as a disinfectant in swimming pools and as an antiseptic for human wounds. The algicidal action of guanidine at low concentrations indicates that it could be an alternative disinfectant or antiseptic for cleaning of the dairy environment and milking equipment, in pre- and postdipping solutions, in the chemical dry therapy of bovine teats and even in the intramammary therapy of P. zopfii infections. This is the first report of the in vitro algicidal effect of guanidine on P. zopfii strains of animal origin. SIGNIFICANCE AND IMPACT OF THE STUDY: Prototheca zopfii genotype 2 is an opportunistic pathogen of bovine mastitis. To date, no effective therapies against protothecal mastitis have been developed. The in vitro algicidal effect of guanidine on 75 P. zopfii genotype 2 strains isolated from cows revealed that all of the isolates were susceptible to the compound at low concentrations, which indicates that guanidine may be used as an antiseptic/disinfectant for dairy milking equipment, in pre- and postdipping solutions, and as a chemical dry therapy or an intramammary therapy. This study describes the in vitro algicidal effect of guanidine on P. zopfii for the first time.

Isolation of infectious microalga Prototheca wickerhamii from a carp (Cyprinus carpio) - a first confirmed case report of protothecosis in a fish.

Protothecosis is a rare infection caused by environmentally ubiquitous achlorophyllic microalgae of the genus Prototheca. Here, we describe a first case of protothecosis in a carp (Cyprinus carpio), which is at the same time the first case of protothecosis in a fish, confirmed by phenotype- and molecular-based methods, including PCR sequencing of the rDNA cluster and protein profiling using matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Evidence of a Prototheca Zopfii Genotype 2 Disseminated Infection in a Dog with Cutaneous Lesions.

Protothecosis is a disease caused by saprophyte aerobic unicellular algae belonging to the genus Prototheca. In dogs, it mainly occurs as a disseminated form, with initial clinical manifestations often referable to the gastrointestinal tract, followed by typical ocular and neurological signs. So far, Prototheca zopfii genotype 2 infection has been reported in severe forms of disseminated protothecosis, while in dogs has never been associated with cutaneous forms. In this study, we describe a case of Prototheca zopfii genotype 2 infection in a dog characterized by nodular and ulcerative dermatitis and with evidence of dissemination. In December 2015, a 5-year-old unneutered male English Setter dog was presented with a 4-month history of footpads ulcerations and multifocal nodular lesions (3-5 cm diameter) on both front limbs. Cytological examination of the aspirated fluid collected from all nodules revealed the presence of sporangic forms compatible with Prototheca spp. organisms. Suspected Prototheca spp. colonies were isolated from the aspirated fluid and identified as Prototheca zopfii genotype 2 by molecular methods. Few days after the visit, the patient developed serious neurological and ocular signs, and the owners elected humane euthanasia. To the authors' knowledge, this case could represent the first report of a disseminated Prototheca zopfii genotype 2 infection associated with cutaneous lesions in a dog. This study underlines the importance of considering Prototheca zopfii genotype 2 infection in the differential etiological diagnosis of nodular and ulcerative dermatitis in dogs.

DISSEMINATED PROTOTHECOSIS IN A RUWENZORI LONG-HAIRED FRUIT BAT ( ROUSETTUS LANOSUS).

An adult male Ruwenzori long-haired fruit bat ( Rousettus lanosus) presented for lethargy and unthriftiness. Physical examination revealed cranial alopecia, mandibular ulceration, and dehydration. Supportive care and antibiotic therapy were initiated. The bat was found dead 3 days after presentation. Necropsy revealed alopecia on the head and body, exposed dried bone on the rostral tip of the mandible, and excessive clear pleural fluid. Lungs were congested and contained miliary white foci disseminated randomly throughout the parenchyma. Subcutaneous, intra-thoracic, and intra-abdominal adipose depots were minimal. Histologic examination of skin and lung revealed the presence of algal-like organisms morphologically consistent with Prototheca spp. Polymerase chain reaction amplification revealed >99% sequence identity match with Prototheca zopfii. Protothecosis has been previously reported in a single bat, Lyle's flying fox ( Pteropus lylei), in Switzerland, but definitive protothecal speciation was not possible.

Protothecosis in a patient with T cell lymphocytic leukemia.

Human protothecosis is a rare infection caused by algae of the genus Prototheca. Prototheca wickerhamii has been recognized as the main species that causes infection in immunocompromised hosts with deficits in innate or cellular immunity. We report a case of persisting subcutaneous protothecosis in a patient with T-cell large granular lymphocyte leukemia, who also presented a history of disseminated histoplasmosis.