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1.
Parasitol Res ; 123(3): 163, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38499865

RESUMEN

Balamuthia mandrillaris is a free-living amoeba that causes meningoencephalitis in mammals. Over 200 cases of infection were reported worldwide, with a fatality rate of over 95%. A clear route of infection was unknown for a long time until a girl died of granulomatous amoebic encephalitis (GAE) in California, USA, in 2003 due to infection with B. mandrillaris detected in a potted plant. Since then, epidemiological studies were conducted worldwide to detect B. mandrillaris in soil and other environmental samples. We previously reported the isolation of B. mandrillaris from the soil in Japan; however, the existing B. mandrillaris culture method with BM3 medium and COS-7 cells was unsuccessful. Therefore, in this study, we aimed to conduct soil analysis to determine the growth conditions of B. mandrillaris. B. mandrillaris-positive soils were defined as soils from which B. mandrillaris was isolated and environmental DNA was PCR-positive. Soils inhabited by B. mandrillaris were alkaline, with high electrical conductivity and characteristics of nutrient-rich soils of loam and clay loam. The results of this study suggest a possible reason for the high prevalence of GAE caused by B. mandrillaris among individuals employed in agriculture-related occupations.


Asunto(s)
Amebiasis , Amoeba , Balamuthia mandrillaris , Encefalitis Infecciosa , Humanos , Animales , Femenino , Balamuthia mandrillaris/genética , Suelo , Amebiasis/epidemiología , Mamíferos
2.
BMC Neurol ; 21(1): 392, 2021 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-34627183

RESUMEN

BACKGROUND: Granulomatous amoebic encephalitis (GAE) is an infrequent and fatal infectious disease worldwide. Antemortem diagnosis in this condition is very difficult because clinical manifestations and neuroimaging are nonspecific. CASE PRESENTATION: A 60-year-old Japanese woman was admitted with a chief complaint of left homonymous hemianopsia. Brain-MRI showed extensive necrotizing lesions enhanced by gadolinium, in the right frontal lobe, right occipital lobe, and left parietal lobe. Epithelioid granulomas of unknown etiology were found in the biopsied brain specimens. Shotgun metagenomic sequencing using a next-generation sequencer detected DNA fragments of Balamuthia mandrillaris in the tissue specimens. The diagnosis of granulomatous amoebic encephalitis was confirmed using an amoeba-specific polymerase chain reaction and immunostaining on the biopsied tissues. CONCLUSIONS: Shotgun metagenomics is useful for the diagnosis of central nervous system infections such as GAE wherein the pathogens are difficult to identify.


Asunto(s)
Amebiasis , Balamuthia mandrillaris , Encefalitis , Amebiasis/diagnóstico , Balamuthia mandrillaris/genética , Encefalitis/diagnóstico , Femenino , Granuloma/diagnóstico , Humanos , Metagenómica , Persona de Mediana Edad
3.
Clin Infect Dis ; 66(4): 548-553, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29401275

RESUMEN

Background: Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. Patient exposure to water containing the ameba typically occurs in warm freshwater lakes and ponds during recreational water activities. In June 2016, an 18-year-old woman died of PAM after traveling to North Carolina, where she participated in rafting on an artificial whitewater river. Methods: We conducted an epidemiologic and environmental investigation to determine the water exposure that led to the death of this patient. Results: The case patient's most probable water exposure occurred while rafting on an artificial whitewater river during which she was thrown out of the raft and submerged underwater. The approximately 11.5 million gallons of water in the whitewater facility were partially filtered, subjected to ultraviolet light treatment, and occasionally chlorinated. Heavy algal growth was noted. Eleven water-related samples were collected from the facility; all were positive for N. fowleri. Of 5 samples collected from the nearby natural river, 1 sediment sample was positive for N. fowleri. Conclusions: This investigation documents a novel exposure to an artificial whitewater river as the likely exposure causing PAM in this case. Conditions in the whitewater facility (warm, turbid water with little chlorine and heavy algal growth) rendered the water treatment ineffective and provided an ideal environment for N. fowleri to thrive. The combination of natural and engineered elements at the whitewater facility created a challenging environment to control the growth of N. fowleri.


Asunto(s)
Amoeba/aislamiento & purificación , Encéfalo/parasitología , Infecciones Protozoarias del Sistema Nervioso Central/diagnóstico , Meningoencefalitis/diagnóstico , Meningoencefalitis/etiología , Ríos/parasitología , Acanthamoeba/genética , Acanthamoeba/aislamiento & purificación , Adolescente , Amoeba/genética , Balamuthia mandrillaris/genética , Balamuthia mandrillaris/aislamiento & purificación , Infecciones Protozoarias del Sistema Nervioso Central/etiología , Ambiente , Resultado Fatal , Femenino , Humanos , Meningoencefalitis/parasitología , Naegleria fowleri/genética , Naegleria fowleri/aislamiento & purificación , North Carolina , Parques Recreativos , Reacción en Cadena de la Polimerasa
4.
Exp Parasitol ; 195: 54-58, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30393165

RESUMEN

Little is known about the prevalence of Balamuthia mandrillaris within the environment due to its difficult isolation, but once an axenic culture is established, it is relatively easy to maintain. As most of the time researchers are interested mainly in isolating B. mandrillaris from environmental samples, the flora that accompanies it becomes second in importance. Therefore, this study aimed to determine which potentially pathogenic free-living amoebae, in addition to B. mandrillaris, could be found co-inhabiting a source of natural thermal water called "Agua Caliente" (Mexico), where this amoeba has previously been detected twice by molecular methods. A third sampling from this same source was carried out to try to isolate B. mandrillaris and other free-living amoebae using 37 and 45 °C as isolation temperatures. For PCR techniques, specific primers were used for B. mandrillaris, Naegleria fowleri, and Acanthamoeba species, plus a universal primer set for the eukaryotic 18S SSU rRNA gene for other isolated amoebae. PCR products were sequenced for final identification. 42 strains of the primary isolate were obtained, but only 34 could be kept in culture. Of them, 23 strains were identified as Naegleria lovaniensis, eight strains as Acanthamoeba jacobsi, two strains as Stenamoeba sp. and only one was identified as Vermamoeba vermiformis. The isolation of B. mandrillaris was once again not successful, but the presence of potentially pathogenic and nonpathogenic free-living amoebae is reported for the first time in this type of water in Mexico thanks to molecular methodology.


Asunto(s)
Amoeba/patogenicidad , Manantiales de Aguas Termales/parasitología , Acanthamoeba/clasificación , Acanthamoeba/genética , Acanthamoeba/aislamiento & purificación , Acanthamoeba/patogenicidad , Amoeba/clasificación , Amoeba/genética , Amoeba/aislamiento & purificación , Balamuthia mandrillaris/clasificación , Balamuthia mandrillaris/genética , Balamuthia mandrillaris/aislamiento & purificación , Balamuthia mandrillaris/patogenicidad , ADN Protozoario/química , ADN Protozoario/aislamiento & purificación , Genotipo , Manantiales de Aguas Termales/química , Concentración de Iones de Hidrógeno , México , Naegleria fowleri/clasificación , Naegleria fowleri/genética , Naegleria fowleri/aislamiento & purificación , Naegleria fowleri/patogenicidad , Filogenia , Reacción en Cadena de la Polimerasa , Espectrofotometría , Temperatura
6.
Parasitol Res ; 117(6): 1801-1811, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29675682

RESUMEN

Brain-eating amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri) have gained increasing attention owing to their capacity to produce severe human and animal infections involving the brain. Early detection is a pre-requisite in successful prognosis. Here, we developed a nanoPCR assay for the rapid detection of brain-eating amoebae using various nanoparticles. Graphene oxide, copper and alumina nanoparticles used in this study were characterized using Raman spectroscopy measurements through excitation with a He-Ne laser, while powder X-ray diffraction patterns were taken on a PANanalytical, X'Pert HighScore diffractometer and the morphology of the materials was confirmed using high-resolution transmission electron microscopy (HRTEM). Using nanoparticle-assisted PCR, the results revealed that graphene oxide, copper oxide and alumina nanoparticles significantly enhanced PCR efficiency in the detection of pathogenic free-living amoebae using genus-specific probes. The optimal concentration of graphene oxide, copper oxide and alumina nanoparticles for Acanthamoeba spp. was determined at 0.4, 0.04 and 0.4 µg per mL respectively. For B. mandrillaris, the optimal concentration was determined at 0.4 µg per mL for graphene oxide, copper oxide and alumina nanoparticles, and for Naegleria, the optimal concentration was 0.04, 4.0 and 0.04 µg per mL respectively. Moreover, combinations of these nanoparticles proved to further enhance PCR efficiency. The addition of metal oxide nanoparticles leads to excellent surface effect, while thermal conductivity property of the nanoparticles enhances PCR productivity. These findings suggest that nanoPCR assay has tremendous potential in the clinical diagnosis of parasitic infections as well as for studying epidemiology and pathology and environmental monitoring of other microbes.


Asunto(s)
Acanthamoeba/genética , Óxido de Aluminio/química , Balamuthia mandrillaris/genética , Cobre/química , Grafito/química , Nanopartículas del Metal/química , Naegleria fowleri/genética , Reacción en Cadena de la Polimerasa/métodos , Acanthamoeba/aislamiento & purificación , Animales , Balamuthia mandrillaris/aislamiento & purificación , Bioensayo , Encéfalo/parasitología , Línea Celular Tumoral , Diagnóstico Precoz , Células HeLa , Humanos , Naegleria fowleri/aislamiento & purificación , Infecciones por Protozoos/diagnóstico , Infecciones por Protozoos/parasitología
7.
Ann Neurol ; 78(5): 722-30, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26290222

RESUMEN

OBJECTIVE: Identification of a particular cause of meningoencephalitis can be challenging owing to the myriad bacteria, viruses, fungi, and parasites that can produce overlapping clinical phenotypes, frequently delaying diagnosis and therapy. Metagenomic deep sequencing (MDS) approaches to infectious disease diagnostics are known for their ability to identify unusual or novel viruses and thus are well suited for investigating possible etiologies of meningoencephalitis. METHODS: We present the case of a 74-year-old woman with endophthalmitis followed by meningoencephalitis. MDS of her cerebrospinal fluid (CSF) was performed to identify an infectious agent. RESULTS: Sequences aligning to Balamuthia mandrillaris ribosomal RNA genes were identified in the CSF by MDS. Polymerase chain reaction subsequently confirmed the presence of B. mandrillaris in CSF, brain tissue, and vitreous fluid from the patient's infected eye. B. mandrillaris serology and immunohistochemistry for free-living amoebas on the brain biopsy tissue were positive. INTERPRETATION: The diagnosis was made using MDS after the patient had been hospitalized for several weeks and subjected to costly and invasive testing. MDS is a powerful diagnostic tool with the potential for rapid and unbiased pathogen identification leading to early therapeutic targeting.


Asunto(s)
Amebiasis/diagnóstico , Amebiasis/genética , Balamuthia mandrillaris/genética , Meningoencefalitis/diagnóstico , Meningoencefalitis/genética , Análisis de Secuencia de ARN/métodos , Anciano , Amebiasis/líquido cefalorraquídeo , Animales , Encéfalo/microbiología , ADN Protozoario/genética , Femenino , Genómica , Humanos , Meningoencefalitis/líquido cefalorraquídeo , Reacción en Cadena de la Polimerasa , Cuerpo Vítreo/microbiología
8.
Parasitol Res ; 115(5): 2111-4, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26965426

RESUMEN

Acanthamoeba spp. are frequently the etiological agents of a severe form of sight-threatening keratitis, called Acanthamoeba keratitis. The contact lens storage solution of a patient with keratitis of unknown genesis was screened using our diagnostic tools to detect potentially pathogenic free-living amoebae (FLA). Culture methods and a triplex quantitative real-time polymerase chain reaction (qPCR) targeting Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris were used in context of this routine screening. While no amoebae were detected by culture, qPCR specifically detected DNA of B. mandrillaris. This FLA is known as the etiological agent of a fatal form of encephalitis in humans and other mammals, Balamuthia amoebic encephalitis (BAE). A fragment of the 18S rDNA gene was amplified from the sample and showed 99 % sequence identity to B. mandrillaris sequences from GenBank. To the best of our knowledge, this is the first report of B. mandrillaris found in association with contact lenses. Although no viable amoeba was obtained by culturing efforts, the verification of B. mandrillaris DNA in the contact lens storage solution demonstrates how easily this pathogen might come into close contact with humans.


Asunto(s)
Balamuthia mandrillaris/aislamiento & purificación , Lentes de Contacto , ADN Protozoario/aislamiento & purificación , Acanthamoeba/genética , Queratitis por Acanthamoeba/parasitología , Animales , Balamuthia mandrillaris/genética , ADN Ribosómico/genética , Alemania , Humanos , Naegleria fowleri/genética , Reacción en Cadena en Tiempo Real de la Polimerasa
9.
Parasitol Res ; 115(2): 541-5, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26468147

RESUMEN

Balamuthia mandrillaris is an opportunistic free-living amoebae (FLA) which has been reported as the causative agent of the fatal Balamuthia amoebic encephalitis (BAE). Currently, the transmission dynamics of this pathogen remain poorly understood although the organism has been associated with soils, and thus, soil exposure has been identified as a risk factor for this pathogenic amoeba. Nevertheless, environmental isolation of B. mandrillaris is a rare event and strains of this amoebic species have been isolated from soil and dust sources only in seven previous reports (Iran, Mexico, USA, Peru, Costa Rica, Guinea Bissau, and Jamaica). In Iran, a previous study reported the isolation of B. mandrillaris from dust collected in the city of Tehran and free of known infectious involvement. Therefore, in this work, 55 soil samples collected from public and recreational areas of East Azerbaijan, North-Western Iran, were investigated for the presence of this pathogen. Samples were cultured in 2% non-nutrient agar plates and were monitored for the presence of B. mandrillaris-like trophozoites and/or cysts. Those samples that were positive for these amoebae by microscopic criteria were then confirmed by PCR amplification and DNA sequencing of the mitochondrial 16S ribosomal DNA (rDNA) of B. mandrillaris. The obtained results revealed the presence of this emerging pathogen in 5 of 55 samples included in the study. Homology analysis of the obtained DNA sequences revealed high similarity with previously isolated strains from clinical and environmental sources. To the best of our knowledge, this is the first report on the isolation of B. mandrillaris from soil sources in Iran related to human activity and the second time that this pathogen is isolated from the environment in this country.


Asunto(s)
Balamuthia mandrillaris/aislamiento & purificación , Suelo/parasitología , Amebiasis , Animales , Balamuthia mandrillaris/genética , ADN Mitocondrial , ADN Ribosómico/genética , Encefalitis , Humanos , Irán , Análisis de Secuencia de ADN , Trofozoítos
10.
Epidemiol Infect ; 143(10): 2245-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25335452

RESUMEN

Balamuthia mandrillaris is an emerging cause of encephalitis in humans. The transmission dynamics are poorly understood due to the high fatality rate and the sporadic nature of cases. Seventy-two soil samples were collected from beaches and the banks of lagoons, rivers, ponds, mineral springs and streams from across Jamaica and assayed for the presence of B. mandrillaris. Seventy-nine sites were sampled and the mitochondrial 16S rDNA gene of B. mandrillaris was amplified and sequenced to confirm the presence of the amoeba. One isolate of B. mandrillaris was recovered from soil from mineral spring which hosts an informal therapeutic mud bath business. Although B. mandrillaris is less frequently isolated from soil than other free-living amoebae, rubbing mud containing the organism onto the skin increases the likelihood of exposure and infection. This first report on the isolation of B. mandrillaris in the Caribbean and its presence in soil where human contact is likely warrants further investigation using serological methods to elucidate exposure patterns.


Asunto(s)
Balamuthia mandrillaris/aislamiento & purificación , Microbiología Ambiental , Balamuthia mandrillaris/clasificación , Balamuthia mandrillaris/genética , ADN Mitocondrial/química , ADN Mitocondrial/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Recolección de Datos , Humanos , Jamaica , Datos de Secuencia Molecular , Peloterapia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
11.
Exp Parasitol ; 145 Suppl: S57-61, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25076486

RESUMEN

Since the first report of Balamuthia mandrillaris as a causative agent of granulomatous amoebic encephalitis in humans, the environmental niche of this amoeba was assumed to be restricted to soil and dust. A single isolation from water was recently made independently by us from Northern Mexico. Now we report the isolation of 8 new strains of B. mandrillaris from Mexico. This continues the pattern of an excess of isolates from North America, compared to other parts of the world. All of the new isolates are environmental isolates, 7 from water samples and one from soil. The identity of each isolate was confirmed by PCR and by examining the sequences of the mitochondrial 16S-like rRNA gene. Success in amplification was determined using comparisons of amplifications of DNA from the strain CDC: V039 and the water strain (ITSON-BM1) as positive controls. The DNA sequences of the new isolates were compared to older strains from clinical cases using phylogenetic analysis, showing very high sequence similarity. The similarity among the new isolates and with previous clinical and environmental isolates of B. mandrillaris was also examined using biochemical and immunological studies. High homogeneity of total protein products, and similarity in antigenic moiety among the eight new isolates and two controls was found. Taken together, the molecular and biochemical studies indicate very low levels of genetic variation within B. mandrillaris.


Asunto(s)
Balamuthia mandrillaris/genética , Agua Dulce/parasitología , Proteínas Protozoarias/química , Suelo/parasitología , Balamuthia mandrillaris/clasificación , Balamuthia mandrillaris/aislamiento & purificación , Western Blotting , Medios de Cultivo , Electroforesis en Gel de Poliacrilamida , México , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
12.
Parasitol Res ; 113(11): 4117-22, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25134946

RESUMEN

Free living amoebae (FLA) are ubiquitous protozoa, which may behave as parasites under certain conditions. Four genera are recognized as causal agents of infections in humans and animals: Naegleria, Sappinia, Acanthamoeba and Balamuthia. This work determines the presence of FLA in combination shower units and employs molecular biology for the characterization of isolates. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of Acanthamoeba genotype T4 in 30% of the units sampled. In addition to Acanthamoeba cysts, trophozoites with morphological characteristics similar to Balamuthia were identified. PCR assay using the mitochondrial 16S rRNA gene as a target confirmed the identification of the amoeba as Balamuthia mandrillaris. Up to date, this is the first report of the isolation of B. mandrillaris in Central America and the fifth report worldwide.


Asunto(s)
Acanthamoeba/aislamiento & purificación , Balamuthia mandrillaris/aislamiento & purificación , Agua Dulce/parasitología , Abastecimiento de Agua , Acanthamoeba/genética , Balamuthia mandrillaris/genética , Costa Rica , ADN Protozoario/genética , Humanos , ARN Ribosómico 16S/genética , Trofozoítos
13.
Parasitol Res ; 113(7): 2509-13, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24781021

RESUMEN

Balamuthia mandrillaris is an opportunistic free-living amoeba that has been reported to cause skin lesions and the fatal Balamuthia amoebic encephalitis (BAE) in humans and other animals. Currently, around 200 human BAE cases have been reported worldwide, although this number is considered to be underestimated. The highest number of BAE cases has been reported in the American continent, mainly in the southwest of the USA. Peru seems to be another hotspot for BAE with around 55 human cases having been identified, usually involving cutaneous infection, especially lesions in the central face area. The isolation of Balamuthia from environmental sources has been reported on only three prior occasions, twice from Californian soils and once from dust in Iran and so it seems that this amoeba is relatively rarely encountered in samples from the environment. We investigated that possibility of finding the amoebae in soil samples from different regions where clinical cases have been reported in Peru. Twenty-one samples were cultured in non-nutrient agar plates and were checked for the presence of B. mandrillaris-like trophozoites and/or cysts. Those samples that were positive for these amoebae by microscopic criteria were then confirmed by PCR amplification and DNA sequencing of the mitochondrial 16S rDNA gene of B. mandrillaris. We have detected the presence of B. mandrillaris in four samples collected in the regions of Piura (3) and Lima (1) where infection cases have been previously reported. We hypothesize that B. mandrillaris is present in Peru in soil and dust which therefore constitutes a source of the infection for the BAE cases previously reported in this country. Further studies should be carried out in the area to confirm the generality of this finding.


Asunto(s)
Balamuthia mandrillaris/aislamiento & purificación , ARN Protozoario/genética , ARN Ribosómico 16S/genética , Suelo/parasitología , Amebiasis/epidemiología , Amebiasis/parasitología , Animales , Balamuthia mandrillaris/genética , Humanos , Perú/epidemiología , Análisis de Secuencia de ADN
14.
Infect Genet Evol ; 119: 105570, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38382768

RESUMEN

INTRODUCTION: Balamuthia amoebic encephalitis (BAE), caused by Balamuthia mandrillaris, is a rare and life-threatening infectious disease with no specific and effective treatments available. The diagnosis of BAE at an early stage is difficult because of the non-specific clinical manifestations and neuroimaging. CASE DESCRIPTION: A 52-year-old male patient, who had no previous history of skin lesions, presented to the emergency department with an acute headache, walking difficulties, and disturbance of consciousness. The patient underwent a series of examinations, including regular cerebrospinal fluid (CSF) studies and magnetic resonance imaging, and tuberculous meningoencephalitis was suspected. Despite being treated with anti-TB drugs, no clinical improvement was observed in the patient. Following corticosteroid therapy, the patient developed a rapid deterioration in consciousness with dilated pupils. Metagenomic next-generation sequencing (mNGS) revealed an unexpected central nervous system (CNS) amoebic infection, and the patient died soon after the confirmed diagnosis. CONCLUSION: This study highlights the application of mNGS for the diagnosis of patients with suspected encephalitis or meningitis, especially those caused by rare opportunistic infections.


Asunto(s)
Amebiasis , Balamuthia mandrillaris , Infecciones Protozoarias del Sistema Nervioso Central , Encefalitis , Encefalitis Infecciosa , Masculino , Humanos , Persona de Mediana Edad , Encefalitis Infecciosa/diagnóstico , Encefalitis/diagnóstico , Encefalitis/patología , Balamuthia mandrillaris/genética , Infecciones Protozoarias del Sistema Nervioso Central/diagnóstico , Amebiasis/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento
15.
Sci Rep ; 13(1): 14318, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37653073

RESUMEN

Balamuthia mandrillaris is a pathogenic protozoan that causes a rare but almost always fatal infection of the central nervous system and, in some cases, cutaneous lesions. Currently, the genomic data for this free-living amoeba include the description of several complete mitochondrial genomes. In contrast, two complete genomes with draft quality are available in GenBank, but none of these have a functional annotation. In the present study, the complete genome of B. mandrillaris isolated from a freshwater artificial lagoon was sequenced and assembled, obtaining an assembled genome with better assembly quality parameter values than the currently available genomes. Afterward, the genome mentioned earlier, along with strains V039 and 2046, were subjected to functional annotation. Finally, comparative genomics analysis was performed, and it was found that homologous genes in the core genome potentially involved in the virulence of Acanthamoeba spp. and Trypanosoma cruzi. Moreover, eleven of fifteen genes were identified in the three strains described as potential target genes to develop new treatment approaches for B. mandrillaris infections. These results describe proteins in this protozoan's complete genome and help prioritize which target genes could be used to develop new treatments.


Asunto(s)
Acanthamoeba , Balamuthia mandrillaris , Balamuthia mandrillaris/genética , Virulencia/genética , Hibridación Genómica Comparativa , Acanthamoeba/genética , Genómica
16.
Acta Trop ; 244: 106956, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37244403

RESUMEN

Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri are pathogenic free-living amoeba (FLA) and are commonly found in the environment, particularly soil. This pathogenic FLA causes central nervous system-affecting granulomatous amebic encephalitis (GAE) or primary amebic meningoencephalitis (PAM) and can also cause keratitis and skin infections. In the present study, we aimed to determine the quantitative concentration of Acanthamoeba spp., B. mandrillaris, and N. fowleri in soil samples collected from places where human contact is high by using a qPCR assay in Izmir, Turkey. A total of 45.71% (n = 16) of Acanthamoeba spp., 20% (n = 7) of B. mandrillaris, and 17.4% (n = 6) of N. fowleri were detected in five different soil sources by the qPCR assay. The quantitative concentration of Acanthamoeba spp., B. mandrillaris, and N. fowleri in various soil sources was calculated at 10 × 105 - 6 × 102, 47 × 104 to 39 × 103, and 9 × 103 - 8 × 102 plasmid copies/gr, respectively. While the highest quantitative concentration of Acanthamoeba spp. and B. mandrillaris was determined in garden soil samples, N. fowleri was detected in potting soil samples. Three different genotypes T2 (18.75%), T4 (56.25%), and T5 (25%) were identified from Acanthamoeba-positive soil samples. Acanthamoeba T4 genotype was the most frequently detected genotype from soil samples and is also the most common genotype to cause infection in humans and animals. To the best of our knowledge, the present study is the first study to identify genotype T5 in soil samples from Turkey. In conclusion, people and especially children should be aware of the hidden danger in the garden and potting soil samples that come into contact most frequently. Public health awareness should be raised about human infections that may be encountered due to contact with the soil. Public health specialists should raise awareness about this hidden danger in soil.


Asunto(s)
Acanthamoeba , Amebiasis , Amoeba , Balamuthia mandrillaris , Naegleria fowleri , Animales , Niño , Humanos , Acanthamoeba/genética , Naegleria fowleri/genética , Balamuthia mandrillaris/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Suelo , Turquía
18.
Ann Lab Med ; 42(2): 196-202, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34635613

RESUMEN

BACKGROUND: Identifying the causal pathogen of encephalitis remains a clinical challenge. A 50-year-old man without a history of neurological disease was referred to our department for the evaluation of an intracranial lesion observed on brain magnetic resonance imaging (MRI) scans, and the pathology results suggested protozoal infection. We identified the species responsible for encephalitis using thymine-adenine (TA) cloning, suitable for routine clinical practice. METHODS: We extracted DNA from a paraffin-embedded brain biopsy sample and performed TA cloning using two universal eukaryotic primers targeting the V4-5 and V9 regions of the 18S rRNA gene. The recombinant plasmids were extracted, and the inserted amplicons were identified by Sanger sequencing and a homology search of sequences in the National Center for Biotechnology Information Basic Local Alignment Search Tool. RESULTS: The infection was confirmed to be caused by the free-living amoeba Balamuthia mandrillaris. Two of 41 colonies recombinant with 18S V4-5 primers and 35 of 63 colonies recombinant with the 18S V9 primer contained B. mandrillaris genes; all other colonies contained human genes. Pathogen-specific PCR ruled out Entamoeba histolytica, Naegleria fowleri, Acanthamoeba spp., and Toxoplasma gondii infections. CONCLUSIONS: This is the first report of B. mandrillaris-induced encephalitis in Korea based on molecular identification. TA cloning with the 18S rRNA gene is a feasible and affordable diagnostic tool for the detection of infectious agents of unknown etiology.


Asunto(s)
Balamuthia mandrillaris , Encefalitis , Adenina , Balamuthia mandrillaris/genética , Clonación Molecular , Encefalitis/diagnóstico , Eucariontes , Humanos , Masculino , Persona de Mediana Edad , Timina
19.
J Int Med Res ; 50(5): 3000605221093217, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35505464

RESUMEN

Balamuthia mandrillaris is a free-living heterotrophic amoeba found in soil that causes a rare and usually fatal granulomatous amebic encephalitis. We report an immunocompetent patient infected with B. mandrillaris encephalitis diagnosed by next-generation sequencing (NGS). Clinical manifestations included sudden headache and epilepsy with disturbance of consciousness. The opening pressure of cerebrospinal fluid (CSF) was 220 mmH2O, with mildly elevated white blood cell numbers and elevated protein levels. Cranial magnetic resonance imaging revealed abnormal signals in the right frontal lobe, left parietal lobe, and left occipital lobe. CSF NGS detected B. mandrillaris. Albendazole and metronidazole combined with fluconazole were administered to the patient immediately, but his condition deteriorated and he eventually died. Encephalitis caused by B. mandrillaris is rare and has a high mortality rate. Clinical manifestations are complex and diverse, but early diagnosis is very important for successful treatment. This can be aided by the metagenomic NGS of CSF.


Asunto(s)
Amebiasis , Balamuthia mandrillaris , Encefalitis , Amebiasis/diagnóstico , Amebiasis/tratamiento farmacológico , Balamuthia mandrillaris/genética , Encefalitis/diagnóstico por imagen , Encefalitis/tratamiento farmacológico , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Imagen por Resonancia Magnética , Masculino
20.
Parasite ; 28: 36, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33843581

RESUMEN

In this review, we focus on the sequenced genomes of the pathogens Naegleria fowleri, Acanthamoeba spp. and Balamuthia mandrillaris, and the remarkable discoveries regarding the pathogenicity and genetic information of these organisms, using techniques related to the various omics branches like genomics, transcriptomics, and proteomics. Currently, novel data produced through comparative genomics analyses and both differential gene and protein expression in these free-living amoebas have allowed for breakthroughs to identify genes unique to N. fowleri, genes with active transcriptional activity, and their differential expression in conditions of modified virulence. Furthermore, orthologous genes of the various nuclear genomes within the Naegleria and Acanthamoeba genera have been clustered. The proteome of B. mandrillaris has been reconstructed through transcriptome data, and its mitochondrial genome structure has been thoroughly described with a unique characteristic that has come to light: a type I intron with the capacity of interrupting genes through its self-splicing ribozymes activity. With the integration of data derived from the diverse omic sciences, there is a potential approximation that reflects the molecular complexity required for the identification of virulence factors, as well as crucial information regarding the comprehension of the molecular mechanisms with which these interact. Altogether, these breakthroughs could contribute to radical advances in both the fields of therapy design and medical diagnosis in the foreseeable future.


TITLE: Application des sciences de l'omique à l'étude de Naegleria fowleri, Acanthamoeba spp. et Balamuthia mandrillaris : état actuel et projections futures. ABSTRACT: Dans cette revue, l'accent est mis sur les génomes séquencés des agents pathogènes Naegleria fowleri, Acanthamoeba spp. et Balamuthia mandrillaris, et les découvertes remarquables concernant la pathogénicité et l'information génétique de ces organismes, en utilisant des techniques liées aux diverses branches de l'omique comme la génomique, la transcriptomique et la protéomique. Actuellement, de nouvelles données produites par des analyses génomiques comparatives et l'expression différentielle des gènes et des protéines dans ces amibes libres ont permis des percées pour identifier des gènes uniques à N. fowleri, des gènes avec une activité transcriptionnelle active et leur expression différentielle dans des conditions de virulence modifiée. En outre, les gènes orthologues des divers génomes nucléaires des genres Naegleria et Acanthamoeba ont été regroupés. Le protéome de B. mandrillaris a été reconstruit grâce aux données du transcriptome, et la structure de son génome mitochondrial décrite de manière détaillée, mettant ainsi une caractéristique unique à jour : un intron de type I avec la capacité d'interrompre les gènes par son activité d'auto-épissage des ribozymes. Avec l'intégration des données issues des diverses sciences omiques, il existe une approximation potentielle qui reflète la complexité moléculaire requise pour l'identification des facteurs de virulence, ainsi que des informations cruciales concernant la compréhension des mécanismes moléculaires avec lesquels ceux-ci interagissent. Dans l'ensemble, ces percées pourraient contribuer à des progrès notables à la fois dans les domaines de la conception de la thérapie et du diagnostic médical dans un avenir proche.


Asunto(s)
Acanthamoeba , Balamuthia mandrillaris , Naegleria fowleri , Acanthamoeba/genética , Balamuthia mandrillaris/genética , Genoma de Protozoos , Genómica , Naegleria fowleri/genética , Proteómica , Transcriptoma , Virulencia
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