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granulomatous amebic encephalitis: a review and report of a spontaneous case from venezuela.granulomatous amebic encephalitis (gae), or meningoencephalitis due to acanthamoeba spp. and leptomyxid ameba are uncommon cns infections that generally occur in immunocompromised hosts. we describe a case of gae caused by balamuthia mandrillaris previously designated as a leptomyxid ameba, in an apparently healthy 14-year-old venezuelan boy. this case was characterized by sudden onset of seizures, focal neurologic signs and by a prolonged clinical course (from november 1992 to march 1993). neur ...19948017178
amebic meningoencephalitis caused by balamuthia mandrillaris.free-living amebae etiologically associated with central nervous system (cns) infection in children have included acanthamoeba, naegleria, and recently, leptomyxid ameba. two previously healthy children are reported with cns infection caused by leptomyxid ameba, recently classified as balamuthia mandrillaris. one child, a 27-month-old boy, had right hemiparesis and aphasia, and the other, a 13-year-old girl, had headache, right hemiparesis, diplopia, and left facial weakness. cerebrospinal fluid ...19948060431
balamuthia mandrillaris, n. g., n. sp., agent of amebic meningoencephalitis in humans and other animals.we recently reported the isolation of a leptomyxid ameba from the brain of a mandrill baboon that died of meningoencephalitis. based on light and electron microscopic studies, animal pathogenicity tests, and immunofluorescence patterns, we conclude that our isolate differs fundamentally from the other two amebas (leptomyxa and gephyramoeba) included in the order leptomyxida. we therefore created a new genus, balamuthia, to accommodate our isolate and described it as balamuthia mandrillaris to re ...19938330028
balamuthia mandrillaris: a newly recognized agent for amebic meningoencephalitis. 19958532431
axenic growth and drug sensitivity studies of balamuthia mandrillaris, an agent of amebic meningoencephalitis in humans and other animals.a cell-free growth medium for the opportunistic pathogenic ameba balamuthia mandrillaris is presented. this represents an advance over the use of monkey kidney cells for growth of the amebas and can be helpful in isolation of these amebas from brain tissue from cases in which amebic meningoencephalitis is a diagnostic possibility, as well as for biochemical and molecular biological studies. three isolates of balamuthia have been cultured in this medium. the cell-free growth system was also used ...19968789020
animal model balamuthia mandrillaris cns infection: contrast and comparison in immunodeficient and immunocompetent mice: a murine model of "granulomatous" amebic encephalitis.balamuthia mandrillaris and several species of acanthamoeba are pathogenic "opportunistic" free-living amebas which cause granulomatous encephalitis (gae) in humans and animals. the granulomatous component is negligible or absent, particularly in immunocompromised individuals. gae is an "opportunistic" infection, usually seen in debilitated, malnourished individuals, in patients undergoing immunosuppressive therapy for organ transplants, and in acquired immunodeficiency syndrome (aids). from aro ...19968965096
free-living, amphizoic and opportunistic amebas.amebas belonging to the genera naegleria, acanthamoeba and balamuthia are free-living, amphizoic and opportunistic protozoa that are ubiquitous in nature. these amebas are found in soil, water and air samples from all over the world. human infection due to these amebas involving brain, skin, lung and eyes has increased significantly during the last 10 years. the epidemiology, immunology, protozoology, pathology, and clinical features of the infections produced by these protozoa differ strikingly ...19979034567
amoebic meningoencephalitis caused by balamuthia mandrillaris in an orang utan.to describe a case of meningoencephalitis caused by balamuthia mandrillaris in an orang utan.19979066963
fatal infections with balamuthia mandrillaris (a free-living amoeba) in gorillas and other old world primates.balamuthia mandrillaris is a newly described free-living amoeba capable of causing fatal meningoencephalitis in humans and animals. because the number of human cases is rapidly increasing, this infection is now considered an important emerging disease by the medical community. a retrospective review of the pathology database for the zoological society of san diego (the san diego zoo and san diego wild animal park) for the period july 1965 through december 1994 revealed five cases of amoebic meni ...19979150541
primary amebic meningoencephalitis due to naegleria fowleri in a south american tapir.naegleria fowleri, acanthamoeba spp., and balamuthia mandrillaris are known to cause fatal central nervous system (cns) disease in human beings. n. fowleri causes acute, fulminating primary amebic meningoencephalitis (pam), which generally leads to death within 10 days. acanthamoeba spp. and b. mandrillaris cause chronic granulomatous amebic encephalitis, which may last for 8 weeks. acanthamoeba spp. and b. mandrillaris also cause cns disease in animals. n. fowleri, however, has been described o ...19979163883
granulomatous amebic encephalitis due to balamuthia mandrillaris (leptomyxiidae): report of four cases from mexico.in this report, we describe four cases of granulomatous amebic encephalitis caused by balamuthia (leptomyxid ameba) in four previously healthy mexican patients. all four cases were characterized by focal neurologic signs, increased intracranial pressure, and cerebral hyperdense lesions in computed tomography scans of the head. these patients underwent craniotomies for evaluation of mass lesions for possible brain tumors. granulomatous chronic inflammatory reaction and amebic trophozoites were fo ...19979230787
fatal granulomatous amoebic encephalitis caused by balamuthia mandrillaris.granulomatous amoebic encephalitis caused by balamuthia mandrillaris is rare (63 human) cases reported worldwide) and fatal. we report a case in a five-year-old boy who had previously been well. for 18 months, he had had a slowly progressive, granulomatous mid facial lesion, but despite extensive investigation definitive diagnosis was made only with the acute onset of neurological signs in the last two weeks of life, when a brain biopsy specimen revealed amoebic trophozoites and cysts. infection ...19979251693
[the cell biology of amebas and ameba-flagellates--parasites of man and animals].the majority of parasitic amoebae and amoeba-flagellates are facultative parasites of animals and humans and only a few of them are obligate parasites (see reviews: sopina, 1997; visvesvara, stehr-green, 1990). among the latter entamoeba histolytica and among the former naegleria fowleri and several species of acanthamoeba are most dangerous for humans. it is still unclear whether balamuthia mandrillaris, pathogenic for monkeys and humans, may be either obligate or facultative parasite (visvesva ...19979324833
balamuthia mandrillaris meningoencephalitis presenting with acute hydrocephalus.the leptomyxid amoeba balamuthia mandrillaris, previously believed to be a harmless soil-inhabiting organism, is now known to be a rare but consistently lethal cause of meningoencephalitis in humans. we report a case of amebic meningoencephalitis caused by b. mandrillaris which presented as a febrile illness with acute hydrocephalus.19979419041
amebic meningoencephalitis caused by balamuthia mandrillaris: case report and review.balamuthia mandrillaris, formerly referred to as a leptomyxid ameba, is a free-living ameba that has recently been identified as a cause of meningoencephalitis. previously, only two genera, naegleria and acanthamoeba, were recognized as causes of central nervous system (cns) infections in humans. in contrast to naegleria, balamuthia causes a subacute-to-chronic infection of the cns. distinct from acanthamoeba, which appears to favor the immunocompromised host, balamuthia is capable of infecting ...19979431377
[human pathology caused by free-living amoebae].naegleria fowleri, acanthamoeba spp. and balamuthia mandrillaris are free-living amoebae that occasionally may induce pathology in human beings. cns disease due to n. fowleri, called "primary" amoebic meningoencephalitis, is acquired after exposure to polluted waters in swimming pools, rivers, and lakes. the clinical course is acute, often fulminant and characterized pathologically by necrotizing hemorrhagic meningoencephalitis, involving mainly the base of the brain, brainstem and cerebellum. i ...19979616966
[central nervous system infection by free-living amebas: report of 3 venezuelan cases].infection of the central nervous system by free living amebas is an unusual event, 344 cases have been reported to date. the disease becomes evident in two different clinical fashions: primary amebic meningoencephalitis (pam) caused by naegleria fowleri and granulomatous amebic encephalitis (gae) induced by spp. of acanthamoeba and balamuthia.19989658480
amebic encephalitis caused by balamuthia mandrillaris in a czech child: description of the first case from europe.we describe a fatal case of amebic encephalitis caused by balamuthia mandrillaris in a 3-year-old czech boy who had never traveled abroad. this is the first such infection reported in europe. the diagnosis was established by brain biopsy, in which abundant trophozoites and a few round amebic cysts were identified. the presence of multiple nucleoli in some trophozoites suggested the organism to be balamuthia mandrillaris and this was confirmed by indirect immunofluorescence. the amebae invaded br ...19989689651
amebic meningoencephalitis caused by balamuthia mandrillaris (leptomyxid ameba) in a horse. 19989786532
efficacy of novel antimicrobials against clinical isolates of opportunistic amebas.we examined the effects of the macrolide antimicrobial agent azithromycin and phenothiazine compounds against clinical isolates of acanthamoeba spp. and balamuthia mandrillaris, opportunistic pathogens of human beings and other animals. acanthamoeba growth was inhibited in vitro at 1, 5, and 10 micrograms/ml of azithromycin, but not the macrolides, erythromycin, and clarithromycin. in experiments attempting to simulate in vivo conditions, azithromycin protected monolayers of rat glioma cells fro ...19989864851
serum antibodies to balamuthia mandrillaris, a free-living amoeba recently demonstrated to cause granulomatous amoebic encephalitis.free-living amoebae cause three well-defined disease entities: a rapidly fatal primary meningoencephalitis, a chronic granulomatous amoebic encephalitis (gae), and a chronic amoebic keratitis. gae occurs in immunocompromised persons. recently, another type of free-living amoeba, balamuthia mandrillaris, has been shown to cause gae. the finding that this amoeba has caused infection in some healthy children has raised the possibility that humans may lack immunity to b. mandrillaris. human serum wa ...199910191243
fluorescent oligonucleotide probes for clinical and environmental detection of acanthamoeba and the t4 18s rrna gene sequence type.the first genus- and subgenus-specific fluorescent oligonucleotide probes for in situ staining of acanthamoeba are described. sequences of these phylogeny-based probes complement the 18s rrna and the gene encoding it (18s rdna). the genus-specific probe (gsp) is a fluorescein-labeled 22-mer specific for acanthamoeba as shown here by its hybridization to growing trophozoites of all 12 known acanthamoeba 18s rdna sequence types and by its failure to hybridize with amoebae of two other genera (hart ...199910405422
[neurological involvement in free living amebiasis].free-living amoeba infection is today a known and outgrowth disease, which is suspected when exists a special skin lesion.199910797916
encephalitis due to a free-living amoeba (balamuthia mandrillaris): case report with literature review.amebic infections can spread to the central nervous system with a lengthy but usually fatal course. a typical case is presented to raise awareness of this increasingly reported infectious process that may have a more favorable outcome if diagnosed in its early stages.200010940434
balamuthia mandrillaris infection. 200111232763
pathologic findings in the adrenal glands of autopsied patients with acquired immunodeficiency syndrome.a morphologic evaluation was carried out on adrenal glands from 128 autopsied patients with the acquired immunodeficiency syndrome (aids). the adrenal gland was compromised in 99.2% of the cases, with distinct pathological features and infectious agents. inflammatory infiltrates were observed in 99.2% of the cases with a predominance of mononuclear cells in 97.4%, affecting mainly the medulla. necrosis, fibrosis, hemorrhages and neoplasias were observed. we also described 3 (2.3%) cases of calci ...200211866207
pediatric granulomatous cerebral amebiasis: a delayed diagnosis.we present four cases of cerebral amebae infection treated at our neurosurgical department. patient 1 was a 12-year-old male with skin lesions of 2 years' progression involving the midface. he received a corticosteroid course, and, after that, he presented a right body hemiparesis. patient 2 was a 5-year-old male, with a past surgical history of fibula fracture and osteomyelitis of 1-year evolution, associated with lesions of the surrounding skin that presented with partial seizures. patient 3 w ...200211897483
balamuthia amebic encephalitis: radiographic and pathologic findings.the radiographic findings of two patients (one, a rare survivor) with meningoencephalitis caused by balamuthia mandrillaris are presented with pathologic correlation.200211901025
survey of sera from encephalitis patients for balamuthia mandrillaris antibody. 200111906014
balamuthia mandrillaris: its pathogenic potential. 200111906084
an autopsy case of amebic meningoencephalitis. the first japanese case caused by balamuthia mandrillaris.we report here the first case of amebic meningoencephalitis caused by balamuthia mandrillaris in a 78-year-old japanese woman with sjögren's syndrome. fourteen days before her death, she presented with high fever and lost consciousness and later developed neck stiffness and abducens palsy. computed tomography scans of the brain demonstrated multiple low-density areas throughout the brain. neuropathologically, hemorrhagic and necrotic lesions with many amebic trophozoites were scattered in the br ...200212416563
identification of balamuthia mandrillaris by pcr assay using the mitochondrial 16s rrna gene as a target.balamuthia mandrillaris is an opportunistic pathogen that causes granulomatous amebic meningoencephalitis in animals, including humans. based on sequence analysis of mitochondrial small-subunit-rrna genes, we developed primers that amplify a balamuthia-specific pcr product. these primers will be useful for retrospective analyses of fixed tissues and possible identification of balamuthia in vivo.200312517892
genotyping of balamuthia mandrillaris based on nuclear 18s and mitochondrial 16s rrna genes.balamuthia mandrillaris is an opportunistically pathogenic ameba that causes fatal granulomatous amebic encephalitis (gae) in vertebrates. previous phylogenetic analyses that included the sequence of a single nuclear small subunit ribosomal rna gene (18s or ssu rdna) from this ameba suggested that balamuthia is closely related to acanthamoeba, another opportunistically pathogenic amebic genus, which includes multiple ssu rdna genotypes. we tested whether this also is true for balamuthia. the nuc ...200312556151
environmental isolation of balamuthia mandrillaris associated with a case of amebic encephalitis.this report describes the first isolation of the ameba balamuthia mandrillaris from an environmental soil sample associated with a fatal case of amebic encephalitis in a northern california child. isolation of the ameba into culture from autopsied brain tissue confirmed the presence of balamuthia: in trying to locate a possible source of infection, soil and water samples from the child's home and play areas were examined for the presence of balamuthia: the environmental samples (plated onto nonn ...200312843060
successful treatment of balamuthia amoebic encephalitis: presentation of 2 cases.case histories are presented of 2 individuals (a 5-year-old girl and 64-year-old man) who developed encephalitis caused by the free-living amoeba balamuthia mandrillaris. both individuals survived after diagnosis and initiation of effective antimicrobial therapy. immunostaining for balamuthia-specific antibody levels identified the causative agent of the infections. antimicrobial therapy with flucytosine, pentamidine, fluconazole, sulfadiazine, and a macrolide antibiotic (azithromycin or clarith ...200314583863
new and re-emerging cutaneous infectious diseases in latin america and other geographic areas.due to environmental factors and inadequate public health measures in many developing countries, new tropical infections, as well as infections that were previously isolated to remote locales, are becoming more prevalent in several areas of latin america. this article discusses some tropical infections and infestations with predominantly cutaneous manifestations. previously uncommon diseases such as gnathostomiasis, mycobacteria ulcerans infection, paederus dermatitis, balamuthia mandrillaris in ...200314717406
fatal granulomatous amebic encephalitis caused by balamuthia mandrillaris presenting as a skin lesion.granulomatous amebic encephalitis is an uncommon central nervous system (cns) infection, usually caused by acanthamoeba spp., which generally occurs in immunocompromised individuals. balamuthia mandrillaris is a recently described free-living ameba that occasionally causes fatal cns disease. the infection might start from a minor, slowly progressive, skin ulceration that can be present for weeks to months before neurologic changes occur. the clinical and histologic presentation is easily confuse ...200414726864
balamuthia mandrillaris: identification of clinical and environmental isolates using genus-specific pcr. 200314736144
balamuthia mandrillaris meningoencephalitis in an immunocompetent patient: an unusual clinical course and a favorable outcome.balamuthia mandrillaris meningoencephalitis is a rare but often fatal infection; only 2 survivors have been reported to date worldwide. we report the case of an apparently immunocompetent patient (72-year-old woman) who developed several episodes of seizures without prior history of respiratory or skin infections. magnetic resonance imaging with contrast revealed 2 ring-enhancing lesions, one in the right precentral region and the other in the left posterotemporal region. open biopsy revealed ba ...200415043486
opportunistic amoebae: challenges in prophylaxis and treatment.this review focuses on free-living amoebae, widely distributed in soil and water, causing opportunistic and non-opportunistic infections in humans: acanthamoeba spp., balamuthia mandrillaris, naegleria fowleri, and sappinia diploidea. diseases include primary amoebic meningoencephalitis (n. fowleri), granulomatous amoebic encephalitis, cutaneous and nasopharyngeal infections (acanthamoeba spp., balamuthia mandrillaris, s. diploidea), and amoebic keratitis (acanthamoeba spp). acanthamoeba, balamu ...200415072770
balamuthia mandrillaris meningoencephalitis: the first case in southeast asia.we present a case of 23-year-old man with acute meningoencephalitis, accompanied by inflammation of a nasal ulcer. he had been healthy until six months prior to admission to the hospital when he had a motorcycle accident. a star-shaped wound at his nose was incurred after falling into a swamp. a computed tomogram of the brain showed two nonenhancing hypodense lesions at the left caudate nucleus and the right parietal lobe, ependymitis and leptomeningeal enhancement. a skin biopsy showed chronic ...200415211011
free-living amoebae as opportunistic and non-opportunistic pathogens of humans and animals.knowledge that free-living amoebae are capable of causing human disease dates back some 50 years, prior to which time they were regarded as harmless soil organisms or, at most, commensals of mammals. first naegleria fowleri, then acanthamoeba spp. and balamuthia mandrillaris, and finally sappinia diploidea have been recognised as etiologic agents of encephalitis; acanthamoeba spp. are also responsible for amoebic keratitis. some of the infections are opportunistic, occurring mainly in immunocomp ...200415313128
balamuthia mandrillaris, an opportunistic agent of granulomatous amebic encephalitis, infects the brain via the olfactory nerve pathway.balamuthia mandrillaris is a free-living ameba and an opportunistic agent of lethal granulomatous amebic encephalitis (gae) in humans and other mammals. its supposed routes of infection have been largely assumed from what is known about acanthamoeba spp. and naegleria fowleri, other free-living amebae and opportunistic encephalitis agents. however, formal proof for any migratory pathway, from gae patients or from animal models, has been lacking. here, immunodeficient mice were infected with b. m ...200415338290
balamuthia mandrillaris from soil samples.balamuthia mandrillaris amoebas are recognized as a causative agent of granulomatous amoebic encephalitis, a disease that is usually fatal. they were first recognized when isolated from the brain of a mandrill baboon that died in the san diego zoo wild life animal park. subsequently, the amoebas have been found in a variety of animals, including humans (young and old, immunocompromised and immunocompetent persons), in countries around the world. until recently, the amoebas had not been recovered ...200415347743
disseminated infection with balamuthia mandrillaris in a dog.bilateral chronic granulomatous nephritis and meningoencephalitis were diagnosed on necropsy of a 2-year-old male great dane dog. the causative agent was identified as balamuthia mandrillaris, based on morphologic features, immunohistochemical staining, and deoxyribonucleic acid detection using the polymerase chain reaction with newly designed primer pairs. trophozoite and cystic forms of the amoeba were evident within the kidneys and brain parenchyma. this is the first report on a b. mandrillar ...200415347823
post-mortem culture of balamuthia mandrillaris from the brain and cerebrospinal fluid of a case of granulomatous amoebic meningoencephalitis, using human brain microvascular endothelial cells.the first isolation in the uk of balamuthia mandrillaris amoebae from a fatal case of granulomatous amoebic meningoencephalitis is reported. using primary cultures of human brain microvascular endothelial cells (hbmecs), amoebae were isolated from the brain and cerebrospinal fluid (csf). the cultures showed a cytopathic effect at 20-28 days, but morphologically identifiable b. mandrillaris amoebae were seen in cleared plaques in subcultures at 45 days. the identification of the organism was late ...200415358823
amebae and ciliated protozoa as causal agents of waterborne zoonotic disease.the roles free-living amebae and the parasitic protozoa entamoeba histolytica and balantidium coli play as agents of waterborne zoonotic diseases are examined. the free-living soil and water amebae naegleria fowleri, acanthamoeba spp., and balamuthia mandrillaris are recognized etiologic agents of mostly fatal amebic encephalitides in humans and other animals, with immunocompromised and immunocompetent hosts among the victims. acanthamoeba spp. are also agents of amebic keratitis. infection is t ...200415567581
september 2004: a 6-year-old girl with headache and stiff neck.free-living amebas in the genera naegleria, acanthamoeba and balamuthia are known to cause cns infections. here we report a case of fatal granulomatous amebic meningoencephalitis (gae) caused by balamuthia mandrillaris in a 6-year-old previously healthy girl who presented with headache and stiff neck. she was treated medically for brain abscess after a ct scan identified a ring-enhancing lesion in the right temporo-parietal area. a brain biopsy showed necrosis and granulomatous inflammation. sub ...200515779245
structural implications of novel diversity in eucaryal rnase p rna.previous eucaryotic rnase p rna secondary structural models have been based on limited diversity, representing only two of the approximately 30 phylogenetic kingdoms of the domain eucarya. to elucidate a more generally applicable structure, we used biochemical, bioinformatic, and molecular approaches to obtain rnase p rna sequences from diverse organisms including representatives of six additional kingdoms of eucaryotes. novel sequences were from acanthamoeba (acathamoeba castellanii, balamuthia ...200515811915
balamuthia mandrillaris, free-living ameba and opportunistic agent of encephalitis, is a potential host for legionella pneumophila bacteria.balamuthia mandrillaris is a free-living ameba and an opportunistic agent of granulomatous encephalitis in humans and other mammalian species. other free-living amebas, such as acanthamoeba and hartmannella, can provide a niche for intracellular survival of bacteria, including the causative agent of legionnaires' disease, legionella pneumophila. infection of amebas by l. pneumophila enhances the bacterial infectivity for mammalian cells and lung tissues. likewise, the pathogenicity of amebas may ...200515870307
detection of balamuthia mitochondrial 16s rrna gene dna in clinical specimens by pcr.balamuthia mandrillaris is a free-living ameba that causes granulomatous amebic encephalitis in both immunocompromised and immunocompetent individuals. because of a lack of pathognomonic symptoms and the difficulty in recognizing amebas in biopsied tissues, most cases are not diagnosed or effectively treated, leading to a >95% mortality. we report here on five cases of balamuthiasis that were diagnosed by indirect immunofluorescence (iif) staining of serum for anti-balamuthia antibodies (titer > ...200516000434
balamuthia mandrillaris stimulates interleukin-6 release in primary human brain microvascular endothelial cells via a phosphatidylinositol 3-kinase-dependent pathway.balamuthia mandrillaris is an emerging protozoan parasite that can cause fatal granulomatous encephalitis. haematogenous spread is a likely route prior to entry into the central nervous system (cns), but it is not clear how circulating amoebae cross the blood-brain barrier. using human brain microvascular endothelial cells (hbmec), which constitute the blood-brain barrier, we determined hbmec inflammatory response to b. mandrillaris and the underlying mechanisms associated with this response. we ...200516027019
neuroparasitic infections: cestodes, trematodes, and protozoans.parasitic infection of the nervous system can produce a variety of symptoms and signs. because symptoms of infection are often mild or nonspecific, diagnosis can be difficult. familiarity with basic epidemiological characteristics and distinguishing radiographic findings can increase the likelihood of detection and proper treatment of parasitic infection of the nervous system. this article discusses the clinical presentation, diagnosis, and treatment for some of the more common infections of the ...200516170739
[pathogenic properties of free-living amoebae isolated from natural and man-made bathing sites in the province of western pomerania].pathogenic amoebae belonging to the genus of acanthamoeba and naegleria, as well as species such as balamuthia mandrillaris and sappinia diploidea cause harmful, life-threatening infections in humans and animals. these amoebae commonly occur in the natural environment. free-living, pathogenic amoebae have hitherto been detected in water reservoirs near poznań, gdańsk, and lublin.200516496612
in-vitro activity of miltefosine and voriconazole on clinical isolates of free-living amebas: balamuthia mandrillaris, acanthamoeba spp., and naegleria fowleri.the anticancer agent miltefosine and the antifungal drug voriconazole were tested in vitro against balamuthia mandrillaris, acanthamoeba spp., and naegleria fowleri. all three amebas are etiologic agents of chronic (balamuthia, acanthamoeba) or fulminant (naegleria) encephalitides in humans and animals and, in the case of acanthamoeba, amebic keratitis. balamuthia exposed to <40 microm concentrations of miltefosine survived, while concentrations of >or=40 microm were generally amebacidal, with v ...200616579814
detection of antibodies against free-living amoebae balamuthia mandrillaris and acanthamoeba species in a population of patients with encephalitis.balamuthia mandrillaris and acanthamoeba species are 2 free-living amoebae responsible for granulomatous amoebic encephalitis in humans and animals. we have screened serum samples from hospitalized patients with encephalitis for antibodies against these 2 amoebae as a means of detecting a disease with few defining symptoms and a poor prognosis.200616586385
balamuthia mandrillaris exhibits metalloprotease activities.balamuthia mandrillaris is a recently identified protozoan pathogen that can cause fatal granulomatous encephalitis. however, the pathogenesis and pathophysiology of b. mandrillaris encephalitis remain unclear. because proteases may play a role in the central nervous system (cns) pathology, we used spectrophotometric, cytopathic and zymographic assays to assess protease activities of b. mandrillaris. using two clinical isolates of b. mandrillaris (from human and baboon), we observed that b. mand ...200616706791
diagnosis of first case of balamuthia amoebic encephalitis in portugal by immunofluorescence and pcr.we report here the first portuguese case of acute fatal granulomatous encephalitis attributed to balamuthia mandrillaris, initially thought to be a brain tumor, which had a progressive and fatal outcome. balamuthia mandrillaris is a free-living amoeba recognized as an uncommon agent of granulomatous encephalitis. infections have been identified in immunocompromised hosts and in immunocompetent pediatric patients. balamuthia infections are very rare, with only two reported cases in europe. the ca ...200616825409
evaluation of prokaryotic and eukaryotic cells as food source for balamuthia mandrillaris.balamuthia mandrillaris is a recently identified free-living protozoan pathogen that can cause fatal granulomatous encephalitis in humans. recent studies have shown that b. mandrillaris consumes eukaryotic cells such as mammalian cell cultures as food source. here, we studied b. mandrillaris interactions with various eukaryotic cells including, monkey kidney fibroblast-like cells (cos-7), human brain microvascular endothelial cells (hbmec) and acanthamoeba (an opportunistic protozoan pathogen) a ...200616847651
[amebic granulomatosis encephalitis due to balamuthia mandrillaris: fatal disease increasingly recognized in latin america]. 200616896491
[granulomatous amebic encephalitis caused by balamuthia mandrillaris. first case diagnosed in chile].the case of a 7 month-old baby boy is presented, with a history of several weeks of evolution of personality changes, convulsions and fever. while he was hospitalized, the brain image study showed multifocal cavity lesions, which varied from millimeters to 4 cm of diameter, not producing mass effect. their biopsy revealed necrotizing encephalitis. in spite of treatment, the lesions progressed and the boy died. the autopsy demonstrated an extensive necrotizing encephalitis with fibrinoid necrotic ...200616896496
[granulomatous amoebic meningoencephalitis by balamuthia mandrillaris: case report and literature review].the free-living amebas naegleria and acanthamoeba are recognized as causal agents of central nervous system infections. recently a third free-living ameba, balamuthia mandrillaris, was identified as the causal agent of granulomatous encephalitis in humans. we report a case of balamuthia encephalitis in an immunocompetent school-age girl who presented cutaneous lesions that compromised the central portion of the face. the skin biopsy revealed granulomatous lesion with positive pcr for non-tubercu ...200616896497
granulomatous cutaneous centrofacial and meningocerebral amebiasis.a 7-year-old, otherwise healthy peruvian boy presented with a 3-month history of an indurated centrofacial plaque. histologic examination revealed a granuloma containing free-living amebae tentatively identified as balamuthia mandrillaris. the patient failed to respond to tentative treatment. he was admitted to the intensive care unit 7 months later with neurologic manifestations of granulomatous amebic encephalitis, which proved fatal. the difficulty in diagnosing this rare presentation of cuta ...200616901188
multiplex real-time pcr assay for simultaneous detection of acanthamoeba spp., balamuthia mandrillaris, and naegleria fowleri.infections caused by naegleria fowleri, acanthamoeba spp., and balamuthia mandrillaris occur throughout the world and pose many diagnostic challenges. to date, at least 440 cases of severe central nervous system infections caused by these amebas have been documented worldwide. rapid and specific identification of these free-living amebas in clinical samples is of crucial importance for efficient case management. we have developed a triplex real-time taqman pcr assay that can simultaneously ident ...200617021087
the interaction between the amoeba balamuthia mandrillaris and extracellular matrix glycoproteins in vitro.balamuthia mandrillaris, a soil amoeba, is the causative agent of balamuthia granulomatous amoebic encephalitis, a life-threatening brain infection. this amoeba is acquired from contaminated soil and may enter the host through cutaneous lesions or through nasal passages, migrating to the lungs or brain. during invasion, b. mandrillaris has access to components of the extracellular matrix (ecm) of the host. therefore, we investigated the interaction of b. mandrillaris with 3 ecm glycoproteins (co ...200717032481
amebic encephalitis caused by balamuthia mandrillaris: report of four cases.we report four fatal cases of amebic encephalitis in children caused by the free-living pathogenic ameba balamuthia mandrillaris. the clinical course ranged from subacute to fulminant. provisional diagnoses were made either shortly before death or postmortem by an indirect immunofluorescent antibody test. although the four cases occurred in different geographic locations, their common features may have diagnostic value for recognizing future cases of amebic encephalitis. the cases occurred in ch ...200312792389
a molecular reassessment of the leptomyxid amoebae.leptomyxid amoebae encompass a diverse assemblage of amoeboid protists that have been implicated as encephalitis-causing agents. this characteristic is attributed to recent studies identifying new members of the leptomyxidae, in particular, balamuthia mandrillaris, that cause the disease. their morphologies range from limax to plasmodial, as well as reticulated and polyaxial. although systematic studies have identified b. mandrillaris as a new member of the leptomyxidae, its precise placement wi ...200011079772
a case of balamuthia mandrillaris meningoencephalitis.balamuthia mandrillaris is a newly described pathogen that causes granulomatous amebic encephalitis, an extremely rare clinical entity that usually occurs in immunosuppressed individuals. we report a case of pathologically proven balamuthia encephalitis with unusual laboratory and radiologic findings. a 52-year-old woman with idiopathic seizures and a 2-year history of chronic neutropenia of unknown cause had a subacute illness with progressive lethargy, headaches, and coma and died 3 months aft ...200010927804
multifocal balamuthia mandrillaris infection in a dog in australia.a 6-year-old male golden retriever, with an 8-month history of seizures and a clinical diagnosis of lymphoma in the central nervous system, was (at the owner's request) euthanized after signs of respiratory distress and shock developed. upon postmortem examination, the diagnoses of meningoencephalitis and pneumonia were made. a histological examination of selected tissues from both the lung and central nervous system revealed a severe, acute, multifocal, amoebic, embolic pneumonia and a severe, ...200717033842
oral infection of immunocompetent and immunodeficient mice with balamuthia mandrillaris amebae.balamuthia mandrillaris is an opportunistic agent of lethal granulomatous amebic encephalitis (gae). in mice, we have shown that intranasally instilled b. mandrillaris amebae infect the brain via the olfactory nerve pathway. in this study, we raised the question whether this ameba might also reach the brain after an oral/gastrointestinal infection. immunocompetent (wt) and immunodeficient (rag) mice received b. mandrillaris amebae by gavage into the esophagus. mice of both groups became ill and ...200717111178
cytopathogenicity of balamuthia mandrillaris, an opportunistic causative agent of granulomatous amebic encephalitis.balamuthia mandrillaris is a free-living ameba and an opportunistic agent of lethal granulomatous amebic encephalitis in humans and other mammals. balamuthia mandrillaris is highly cytopathic but, in contrast to the related acanthamoeba, does not feed on bacteria and seems to feed only on eukaryotic cells instead. most likely, the cytopathogenicity of b. mandrillaris is inseparable from its infectivity and pathogenicity. to better understand the mechanisms of b. mandrillaris cytopathogenicity, a ...200617123409
the threat from balamuthia mandrillaris. 200717172508
effects of human serum on balamuthia mandrillaris interactions with human brain microvascular endothelial cells.balamuthia mandrillaris is a free-living amoeba and a causative agent of fatal granulomatous encephalitis. in the transmission of b. mandrillaris into the central nervous system (cns), haematogenous spread is thought to be the primary step, followed by blood-brain barrier penetration. the objectives of the present study were (i) to determine the effects of serum from healthy individuals on the viability of b. mandrillaris, and (ii) to determine the effects of serum on b. mandrillaris-mediated bl ...200717172513
opportunistic infections in 547 organ transplant recipients receiving alemtuzumab, a humanized monoclonal cd-52 antibody.alemtuzumab is being increasingly used for the prevention and/or treatment of acute allograft rejection in organ transplant recipients. we assessed the risks of infection in, to our knowledge, the largest cohort and broadest range of organ transplant recipients yet reported to have received alemtuzumab.200717173218
pathogenic and opportunistic free-living amoebae: acanthamoeba spp., balamuthia mandrillaris, naegleria fowleri, and sappinia diploidea.among the many genera of free-living amoebae that exist in nature, members of only four genera have an association with human disease: acanthamoeba spp., balamuthia mandrillaris, naegleria fowleri and sappinia diploidea. acanthamoeba spp. and b. mandrillaris are opportunistic pathogens causing infections of the central nervous system, lungs, sinuses and skin, mostly in immunocompromised humans. balamuthia is also associated with disease in immunocompetent children, and acanthamoeba spp. cause a ...200717428307
infections caused by pathogenic free-living amebas (balamuthia mandrillaris and acanthamoeba sp.) in horses.this article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by balamuthia mandrillaris and acanthamoeba culbertsoni and systemic infections caused by acanthamoeba sp. the former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with aspergillus sp. and/or escherichia coli and pseudomonas sp. the clinico ...200717459867
balamuthia mandrillaris amebic encephalitis.amebic encephalitis caused by balamuthia spp is an increasingly recognized chronic granulomatous central nervous system infectious process, which may affect both immunocompetent and immunocompromised individuals. the course of the disease is insidious and fatal in most cases, mainly due to delayed diagnosis, difficulty in isolation and/or identification of the organism, and lack of well-established amebicidal therapeutic regimens. this article reviews the clinicopathologic characteristics of inf ...200717618553
balamuthia mandrillaris interactions with human brain microvascular endothelial cells in vitro.balamuthia amoebic encephalitis (bae) is a serious human disease almost always leading to death. an important step in bae is amoebae invasion of the bloodstream, followed by their haematogenous spread. balamuthia mandrillaris entry into the central nervous system most likely occurs at the blood-brain barrier sites. using human brain microvascular endothelial cells (hbmecs), which constitute the blood-brain barrier, this study determined (i) the ability of b. mandrillaris to bind to hbmecs and (i ...200717644721
effect of antimicrobial compounds on balamuthia mandrillaris encystment and human brain microvascular endothelial cell cytopathogenicity.cycloheximide, ketoconazole, or preexposure of organisms to cytochalasin d prevented balamuthia mandrillaris-associated cytopathogenicity in human brain microvascular endothelial cells, which constitute the blood-brain barrier. in an assay for inhibition of cyst production, these three agents prevented the production of cysts, suggesting that the biosynthesis of proteins and ergosterol and the polymerization of actin are important in cytopathogenicity and encystment.200717875991
demonstration of balamuthia and acanthamoeba mitochondrial dna in sectioned archival brain and other tissues by the polymerase chain reaction.granulomatous amoebic encephalitis (gae) is a usually fatal disease caused by the free-living amoebae balamuthia mandrillaris and acanthamoeba spp. the intent of this study was to determine if the polymerase chain reaction (pcr) could be used retrospectively to detect amoeba mitochondrial 16s ribosomal ribonucleic acid gene deoxyribonucleic acid (dna) in confirmed archival tissue sections from gae cases stored in our laboratories for 1 to 34 years. the dna was extracted from deparaffinized secti ...200817899196
the ameba balamuthia mandrillaris feeds by entering into mammalian cells in culture.microscopic observations of live cultures of the pathogenic ameba balamuthia mandrillaris and mammalian cells showed that amebic feeding involved the invasion of the pseudopodia, and/or the whole ameba into the cells. the ameba, recognized by their size and flow of organelles in the cytosol, was seen to extend the tip of a pseudopodium into the cytoplasm of a cell where it moved about leaving visible damage when retracted. in rounded cells, whole amebas were seen to enter into and move around be ...200717910691
balamuthia amoebic encephalitis: an emerging disease with fatal consequences.balamuthia amoebic encephalitis (bae), caused by the protozoan pathogen, balamuthia mandrillaris, is a serious human disease with fatal consequences and a mortality rate of more than 95%. a key factor that contributes to the high mortality is the incomplete understanding of its pathogenesis and pathophysiology. the most distressing aspect is that the high level of mortality is due to lack of awareness combined with the lack of effective drugs. early diagnosis followed by aggressive treatment may ...200817913450
histopathologic spectrum and immunohistochemical diagnosis of amebic meningoencephalitis.traditionally, naegleria fowleri infections are labeled primary amebic meningoencephalitis because of prominent meningeal neutrophilic inflammation. acanthamoeba spp. and balamuthia mandrillaris are labeled granulomatous amebic encephalitis because of parenchymal granulomatous inflammation. we compared histopathologic and immunohistochemical features of 18 cases with central nervous system free-living ameba infections. immunohistochemical assays using polyclonal antibodies that reacted specifica ...200717932496
fatal amebic encephalitis caused by balamuthia mandrillaris in an immunocompetent host: a clinicopathological review of pathogenic free-living amebae in human hosts.encephalitis caused by balamuthia amebic species is an increasingly recognized chronic granulomatous infectious process that may affect both immunocompetent and immunocompromised individuals. the course of the disease is insidious but fatal in most cases, mainly because of delayed diagnosis, difficulty in isolation and/or identification of the organism, and lack of well-established therapeutic regimens. we report a fatal case of balamuthia mandrillaris chronic granulomatous encephalitis in an im ...200718022130
demonstration of balamuthia and acanthamoeba mitochondrial dna in sectioned archival brain and other tissues by the polymerase chain reaction.granulomatous amoebic encephalitis (gae) is a usually fatal disease caused by the free-living amoebae balamuthia mandrillaris and acanthamoeba spp. the intent of this study was to determine if the polymerase chain reaction (pcr) could be used retrospectively to detect amoeba mitochondrial 16s rrna gene dna in confirmed archival tissue sections from gae cases stored in our laboratories for 1 to 34 years. the dna was extracted from deparaffinized sections, and appropriate primer sets for each of t ...200818038238
disseminated balamuthia mandrillaris amoeba infection in an aids patient from brazil.this report describes a 32-year-old male aids patient. he presented with a clinical picture characterized by severe headache, blurred vision, and fever that had lasted for 10 days. at admission, no remarkable neurologic abnormalities were observed. cranial tomography showed a ring-enhanced lesion with edema and a mass effect in the right occipital lobe. the initial diagnosis was toxoplasmosis, and treatment of this was administered. however, 5 days later, the patient's clinical status worsened a ...200718165529
balamuthia mandrillaris resistance to hostile conditions.the resistance of balamuthia mandrillaris to physical, chemical and radiological conditions was tested. following treatments, viability was determined by culturing amoebae on human brain microvascular endothelial cells for up to 12 days. b. mandrillaris cysts were resistant to repeated freeze-thawing (five times), temperatures of up to 70 degrees c, 0.5 % sds, 25 p.p.m. chlorine, 10 microg pentamidine isethionate ml(-1) and 200 mj uv irradiation cm(-2).200818349360
increasing importance of balamuthia mandrillaris.balamuthia mandrillaris is an emerging protozoan parasite, an agent of granulomatous amoebic encephalitis involving the central nervous system, with a case fatality rate of >98%. this review presents our current understanding of balamuthia infections, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of balamuthia that may be potential targets for therapeutic interventions and/or for the development of preventative measures.200818625680
balamuthia amebic encephalitis--california, 1999-2007.balamuthia mandrillaris is a free-living ameba that causes encephalitis in humans (both immunocompetent and immunocompromised), horses, dogs, sheep, and nonhuman primates. the ameba is present in soil and likely is transmitted by inhalation of airborne cysts or by direct contamination of a skin lesion. approximately 150 cases of balamuthiasis have been reported worldwide since recognition of the disease in 1990. balamuthiasis is difficult to diagnose because 1) the clinical symptoms mimic those ...200818636064
fatal granulomatous amoebic meningoencephalitis due to balamuthia mandrillaris.amoebic infections of the central nervous system (cns) are very rare and usually fatal. a 33-year-old bolivian male injured his elbow 18 months ago in an accident and, months later, developed multiple skin lesions. he was admitted with confusion, and brain images showed large multifocal lesions with mass effect. review of the skin biopsy revealed the presence of amoebic trophozoites within a granulomatous inflammation. despite treatment, he continued to deteriorate and died 17 days after admissi ...200818675522
balamuthia mandrillaris, agent of amebic encephalitis: detection of serum antibodies and antigenic similarity of isolates by enzyme immunoassay.we report the development of an enzyme-linked immunosorbent assay (elisa) for detecting antibodies to balamuthia mandrillaris, a free-living ameba that is an etiologic agent of granulomatous amebic encephalitis (gae). as part of the california encephalitis project (cep), we have tested serum and cerebrospinal fluid (csf) samples from a subgroup of 130 hospitalized encephalitis patients (out of approximately 430 samples) over a 16-month period. case criteria were based on clinical, laboratory, an ...200818681845
demonstration and partial characterization of ecto-atpase in balamuthia mandrillaris and its possible role in the host-cell interactions.to investigate the presence and partial characterization of ecto-atpase in balamuthia mandrillaris.200818761612
balamuthia mandrillaris meningoencephalitis in an immunocompromised patient. case report.balamuthia mandrillaris is a rare but increasingly recognized cause of amebic encephalitis, yet it remains poorly understood. the condition is almost universally fatal, and due to diagnostic difficulty, most cases are identified postmortem. the authors report a case of balamuthia amebic encephalitis in a patient with combined variable immunodeficiency in which a rare antemortem diagnosis was made via brain biopsy. despite broad-spectrum antimicrobial therapy, the outcome was fatal. such presenta ...200919025354
assessment of balamuthia mandrillaris-specific serum antibody concentrations by flow cytometry.a flow cytometry (fluorescence-activated cell sorter)-based assay was adapted to detect and quantify antibodies to balamuthia mandrillaris, a causative agent of fatal amoebic encephalitis (bae), and to acanthamoeba species. with sera from bae patients for positive and a group of inconspicuous volunteers for negative reference, most of the 237 sera from random blood donors, patients with atypical encephalitis, atypical pneumonitis, visceral amoebiasis and toxoplasmosis and from subjects working w ...200919039606
detection of balamuthia mandrillaris dna by real-time pcr targeting the rnase p gene.the free-living amoeba balamuthia mandrillaris may cause fatal encephalitis both in immunocompromised and in - apparently - immunocompetent humans and other mammalian species. rapid, specific, sensitive, and reliable detection requiring little pathogen-specific expertise is an absolute prerequisite for a successful therapy and a welcome tool for both experimental and epidemiological research.200819055756
erratum balamuthia mandrillaris meningoencephalitis in an immunocompromised patient. 200919199467
the cyst wall carbohydrate composition of balamuthia mandrillaris.balamuthia mandrillaris is an opportunistic cyst-producing amoeba that can cause rare, but fatal, balamuthia amoebic encephalitis (bae). cysts are resistant to harsh environmental conditions and many antimicrobial compounds and thus can contribute to bae recurrence. however, little is known of cyst wall synthesis, cyst wall composition, or how encystment is induced. in this study, we examined the carbohydrate composition of the cyst wall. the major components were mannose (20.9 mol%) and glucose ...200919214576
[amebic meningoencephalitis].it has been reported that amebic meningoencephalitis is caused by some rhizopods, which are taxonomically different from entamoeba histolytica which is well known as the causative agent of amebic dysentery. different types of human meningoencephalitis have been reported to be caused by amphizoic amebae, which are not obligatorily parasitic (endozoic) but are usually free-living (exozoic) in nature, i.e., in environmental water and soil: naegleria fowleri causes acute primary amebic meningoenceph ...200919235460
under the radar: balamuthia amebic encephalitis.we present data from 9 years (1999-2008) of tests for balamuthia mandrillaris, an agent of amebic encephalitis that were conducted as part of the california encephalitis project.200919236272
molecular confirmation of sappinia pedata as a causative agent of amoebic encephalitis.pathogenic free-living amoebae, such as acanthamoeba species, balamuthia mandrillaris, and naegleria fowleri, are known to cause infections of the central nervous system in human and other animals. in 2001, a case of human encephalitis was reported that was caused by another amoeba with morphological features suggestive of sappinia. the amoeba originally identified as sappinia diploidea was identified, most likely as s. pedata, by use of newly developed real-time polymerase chain reaction assays ...200919302010
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