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Pathogens (Basel, Switzerland) Dec 2022Pathogenic free-living amoeba (FLA) such as spp., , and are causative agents of fatal amoebic encephalitis/meningoencephalitis. The diagnosis of such infections is...
BACKGROUND
Pathogenic free-living amoeba (FLA) such as spp., , and are causative agents of fatal amoebic encephalitis/meningoencephalitis. The diagnosis of such infections is challenging due to a lack of clinical suspicion and expertise in microscopic identification. We evaluated the performance of molecular assays for the timely and accurate detection of FLA-causing central nervous system (CNS) afflictions.
METHODS
This study included samples from 156 patients with suspected encephalitis/meningoencephalitis, including 149 cerebrospinal fluid (CSF) samples, 5 brain tissue biopsies, and 2 brain abscess samples. All the samples were subjected to PCR-based detection of spp., , and . The diagnostic characteristics and the inter-rater reliability scores were evaluated for parasite-specific polymerase chain reaction (PCR) using culture on non-nutrient agar (NNA)/microscopy or histopathological examination as a confirmatory test for spp. and and histopathology for .
RESULTS
We detected 11 samples positive for FLA, including 6 spp., 3 , and 2 . Furthermore, all 11 samples were positive according to the confirmatory tests, i.e., culture on NNA/microscopy/histopathology in the case of spp. and and histopathology of tissue biopsies for . The inter-rater reliability between the PCRs and the confirmatory tests for the detection of spp., , and was 100%.
CONCLUSIONS
The PCR-based detection of FLA in patients suspected of encephalitis/meningoencephalitis was found to be fast, efficient, and reliable in our study. We suggest the use of these PCRs in laboratories to obtain additional data on their efficiency in diagnosing FLA infections of the CNS. The present study was conducted with a small sample size of 156 patient samples, and we found only six spp., three , and two . The present study should be conducted on a larger sample size for better evaluation of the primer pairs.
PubMed: 36558843
DOI: 10.3390/pathogens11121509 -
ACS Omega Jun 2020and are free-living amoebae that cause infection of the central nervous system, granulomatous amoebic encephalitis (GAE) and primary amoebic meningoencephalitis (PAM),...
and are free-living amoebae that cause infection of the central nervous system, granulomatous amoebic encephalitis (GAE) and primary amoebic meningoencephalitis (PAM), respectively. The fact that mortality rates for cases of GAE and PAM are more than 95% indicates the need for new therapeutic agents against those amoebae. Considering that curcumin exhibits a wide range of biological properties and has shown efficacy against , we evaluated the amoebicidal properties of curcumin against and . Curcumin showed significant amoebicidal activities with an AC of 172 and 74 μM against and , respectively. Moreover, these compounds were also conjugated with gold nanoparticles to further increase their amoebicidal activities. After conjugation with gold nanoparticles, amoebicidal activities of the drugs were increased by up to 56 and 37% against and , respectively. These findings are remarkable and suggest that clinically available curcumin and our gold-conjugated curcumin nanoparticles hold promise in the improved treatment of fatal infections caused by brain-eating amoebae and should serve as a model in the rationale development of therapeutic interventions against other infections.
PubMed: 32548431
DOI: 10.1021/acsomega.0c01305 -
Bioengineering (Basel, Switzerland) Jul 2022A spheroid is a cell aggregate in a three-dimensional context; thereby, it recapitulates the cellular architecture in human tissue. However, the utility of spheroids as...
A spheroid is a cell aggregate in a three-dimensional context; thereby, it recapitulates the cellular architecture in human tissue. However, the utility of spheroids as an assay for host-parasite interactions remains unexplored. This study demonstrates the potential use of neurospheroids for assessing the cytotoxicity of the life-threatening pathogenic amoeba . The neuroblastoma SH-SY5Y cells formed a spheroid in a hanging drop of culture medium. Cellular damage caused by trophozoites on human neuronal spheroids was observed using microscopic imaging and ATP detection. trophozoites rapidly caused a decrease in ATP production in the spheroid, leading to loss of neurospheroid integrity. Moreover, 3D confocal microscopy imaging revealed interactions between the trophozoites and SH-SY5Y neuronal cells in the outer layer of the neurospheroid. In conclusion, the neurospheroid allows the assessment of host cell damage in a simple and quantitative manner.
PubMed: 35877381
DOI: 10.3390/bioengineering9070330 -
MMWR. Morbidity and Mortality Weekly... Jul 2008Balamuthia mandrillaris is a free-living ameba that causes encephalitis in humans (both immunocompetent and immunocompromised), horses, dogs, sheep, and nonhuman...
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 of several other types of encephalitis, 2) few laboratories perform appropriate diagnostic testing, and 3) many physicians are unaware of the disease. The lack of recognition and subsequent delay in diagnosis might be a factor in its high mortality. Since 1998, the California Encephalitis Project (CEP) has been testing encephalitis cases for both common and uncommon agents known to cause encephalitis, including Balamuthia. This report describes the 10 balamuthiasis cases identified by CEP during 1999-2007. The preliminary diagnoses in these cases included neurotuberculosis, viral meningoencephalitis, neurocysticercosis, and acute disseminated encephalomyelitis. All but one patient died. These findings underscore the importance of increasing awareness among clinicians, epidemiologists, and public health officials for timely recognition and potential treatment of Balamuthia encephalitis.
Topics: Adolescent; Adult; Aged; Amebiasis; Amoeba; Animals; California; Child; Child, Preschool; Encephalitis; Female; Humans; Infant; Male; Middle Aged; Risk Factors
PubMed: 18636064
DOI: No ID Found -
Diseases (Basel, Switzerland) Apr 2023Given the opportunity and access, pathogenic protists ( and ) can produce fatal infections involving the central nervous system. In the absence of effective treatments,...
Given the opportunity and access, pathogenic protists ( and ) can produce fatal infections involving the central nervous system. In the absence of effective treatments, there is a need to either develop new antimicrobials or enhance the efficacy of existing compounds. Nanocarriers as drug delivery systems are gaining increasing attention in the treatment of parasitic infections. In this study, novel nanocarriers conjugated with amphotericin B and curcumin were evaluated for anti-amoebic efficacy against and . The results showed that nanocarrier conjugated amphotericin B exhibited enhanced cidal properties against both amoebae tested compared with the drug alone. Similarly, nanocarrier conjugated curcumin exhibited up to 75% cidal effects versus approx. 50% cidal effects for curcumin alone. Cytopathogenicity assays revealed that the pre-treatment of both parasites with nanoformulated-drugs reduced parasite-mediated host cellular death compared with the drugs alone. Importantly, the cytotoxic effects of amphotericin B on human cells alone were reduced when conjugated with nanocarriers. These are promising findings and further suggest the need to explore nanocarriers as a means to deliver medicine against parasitic infections.
PubMed: 37092440
DOI: 10.3390/diseases11020058 -
Scientific Reports Aug 2023Balamuthia mandrillaris is a pathogenic protozoan that causes a rare but almost always fatal infection of the central nervous system and, in some cases, cutaneous...
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.
Topics: Balamuthia mandrillaris; Virulence; Comparative Genomic Hybridization; Acanthamoeba; Genomics
PubMed: 37653073
DOI: 10.1038/s41598-023-41657-6 -
BioMed Research International 2013The present work focuses on a local survey of free-living amoebae (FLA) that cause opportunistic and nonopportunistic infections in humans. Determining the prevalence of...
The present work focuses on a local survey of free-living amoebae (FLA) that cause opportunistic and nonopportunistic infections in humans. Determining the prevalence of FLA in water sources can shine a light on the need to prevent FLA related illnesses. A total of 150 samples of tap water were collected from six districts of Sivas province. The samples were filtered and seeded on nonnutrient agar containing Escherichia coli spread. Thirty-three (22%) out of 150 samples were found to be positive for FLA. The FLA were identified by morphology and by PCR using 18S rDNA gene. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of three different species, Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. Naegleria fowleri, Balamuthia mandrillaris, or Sappinia sp. was not isolated during the study. All A. castellanii and A. polyphaga sequence types were found to be genotype T4 that contains most of the pathogenic Acanthamoeba strains. The results indicated the occurrence and distribution of FLA species in tap water in these localities of Sivas, Turkey. Furthermore, the presence of temperature tolerant Acanthamoeba genotype T4 in tap water in the region must be taken into account for health risks.
Topics: Amebiasis; Amoeba; Drinking Water; Humans; Turkey; Water Pollutants; Water Supply
PubMed: 23971043
DOI: 10.1155/2013/675145 -
Pathogens and Global Health Jun 2014Free-living amoebae (FLA) include opportunistic pathogens such as Naegleria fowleri, Balamuthia mandrillaris, and the genera Sappinia and Acanthamoeba. In this study, a...
Free-living amoebae (FLA) include opportunistic pathogens such as Naegleria fowleri, Balamuthia mandrillaris, and the genera Sappinia and Acanthamoeba. In this study, a survey was conducted in order to evaluate the presence of potentially pathogenic amoebic strains in water samples collected from wells located in the western part of Guinea-Bissau. The samples were left to precipitate for 48 hours and then the sediments were seeded on non-nutrient agar plates containing Escherichia coli spread and cultures were checked daily for the presence of FLA. Identification of FLA strains was based on the morphological and polymerase chain reaction (PCR) using the 18S rDNA or 16S mitochondrial rDNA genes in the case of Naegleria and Balamuthia genera, respectively. In the case of positive samples of Acanthamoeba, strains were further classified at the genotype level by sequencing the diagnostic fragment 3 (DF3) region located in the 18S rDNA gene as previously described. Sappinia sp. was not isolated during the study and thus, no molecular analysis was performed for this genus. The obtained results revealed the presence of Acanthamoeba (genotypes T3 and T4), Naegleria fowleri, and Balamuthia mandrillaris. To the best of our knowledge, this is the first report demonstrating the presence of FLA in water bodies from Guinea-Bissau and the first report on the isolation of Balamuthia mandrillaris from environmental sources in Africa.
Topics: Amebiasis; Animals; Antigens, Protozoan; Balamuthia mandrillaris; Drinking Water; Gene Expression Regulation; Genes, rRNA; Guinea-Bissau; Humans; Immunocompromised Host; Naegleria fowleri; Public Health; Water Supply
PubMed: 24934796
DOI: 10.1179/2047773214Y.0000000143 -
IDCases 2021is a free-living amoeba that may result in a disseminated infection of the central nervous system called granulomatous amoebic encephalitis. We present a case of...
is a free-living amoeba that may result in a disseminated infection of the central nervous system called granulomatous amoebic encephalitis. We present a case of balamuthiasis in a Hispanic male with poorly controlled type 2 diabetes mellitus (hemoglobin A1C of 12.2 %) who did not have access to healthcare. He initially presented with the non-specific symptoms of blurry vision, headache and imbalance which rapidly progressed to altered mental status over two months. Imaging revealed multiple peripherally enhancing lesions throughout the cerebellum and cortical regions which corresponded to the patient's deficits. Brain biopsy showed amoebic forms consistent with and later confirmed with cerebrospinal fluid PCR. Our patient was treated with a combination of various antimicrobials, including azithromycin, fluconazole, flucytosine, sulfadiazine, and miltefosine. Unfortunately, his prognosis continued to worsen and he ultimately died after being placed on comfort care.
PubMed: 34189033
DOI: 10.1016/j.idcr.2021.e01174 -
Heliyon Mar 2024amoebic encephalitis (BAE) is a rare and severe parasitic infection of the central nervous system. Its delayed diagnosis and treatment are often due to the lack of...
amoebic encephalitis (BAE) is a rare and severe parasitic infection of the central nervous system. Its delayed diagnosis and treatment are often due to the lack of specific clinical manifestations and its poor prognosis. Reported mortality rates reach around 95%. The Balamuthia mandrillaris is also known as the "brain-eating amoeba." Recently, the use of metagenomic next-generation sequencing (mNGS) in clinical settings has led to an increase in BAE diagnoses. A case report detailing the use of mNGS to diagnose granulomatous encephalitis caused by the Baramsi amoeba has improved clinicians' understanding of this disease and helped reduce misdiagnoses and missed diagnoses.
PubMed: 38434374
DOI: 10.1016/j.heliyon.2024.e26905