Primary amebic encephalitis (PAM) is a devastating central nervous system infection caused by Naegleria fowleri, a free-living amoeba, which can survive in soil and warm fresh water. Here, a 43-year-old healthy male was exposed to warm freshwater 5 days before the symptom onset. He rapidly developed severe cerebral edema before the diagnosis of PAM and was treated with intravenous conventional amphotericin B while died of terminal cerebral hernia finally. Comparing the patients with PAM who has similar clinical symptoms to those with other common types of meningoencephalitis, this infection is probably curable if treated early and aggressively. PAM should be considered in the differential diagnosis of purulent meningoencephalitis, especially in patients with recent freshwater-related activities during the hot season.
Adult ; Amoeba ; Amphotericin B ; Brain Edema ; Central Nervous System Infections ; Central Nervous System Protozoal Infections ; Diagnosis ; Diagnosis, Differential ; Encephalitis ; Encephalocele ; Fresh Water ; Humans ; Male ; Meningoencephalitis ; Naegleria fowleri ; Seasons ; Soil

Acanthamoeba castellanii has ubiquitous distribution and causes primary acanthamoebic keratitis (AK). AK is a common disease in contact lens wearers and results in permanent visual impairment or blindness. In this study, we observed the cytopathic effect, in vitro cytotoxicity, and secretion pattern of cytokines in human corneal epithelial cells (HCECs) induced by A. castellanii trophozoites and/or cysts. Morphological observation revealed that panked dendritic HCECs co-cultured with amoeba cysts had changed into round shape and gradually died. Such changes were more severe in co-culture with cyst than those of co-cultivation with trophozoites. In vitro cytotoxicity assay revealed the highest cytotoxicity to HCECs in the co-culture system with amoeba cysts. A. castellanii induced the expression of IL-1α, IL-6, IL-8, and CXCL1 in HCECs. Secreted levels of IL-1α, IL-6, and IL-8 in HCECs co-cultured with both trophozoites and cysts were increased at an early incubation time (3 and 6 hr). These results suggested that cytopathic changes and pro-inflammatory cytokines release of HCECs in response to A. castellanii, especially amoebic cysts, are an important mechanism for AK development.
Acanthamoeba castellanii ; Acanthamoeba ; Amoeba ; Blindness ; Coculture Techniques ; Cytokines ; Epithelial Cells ; Humans ; In Vitro Techniques ; Interleukin-6 ; Interleukin-8 ; Keratitis ; Trophozoites ; Vision Disorders

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hot-spring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.
Acanthamoeba ; Amoeba ; Animals ; Asia, Southeastern ; Asian Continental Ancestry Group ; Encephalitis ; Humans ; Keratitis ; Nanoparticles ; Nanotechnology ; Parasites ; Plants, Medicinal ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Soil ; Swimming Pools ; Water

Pathogenic Naegleria fowleri, Acanthamoeba castellanii, and Acanthamoeba polyphaga, are distributed worldwide. They are causative agents of primary amoebic meningoencephalitis or acanthamoebic keratitis in humans, respectively. Trophozoites encyst in unfavorable environments, such as exhausted food supply and desiccation. Until recently, the method of N. fowleri encystation used solid non-nutrient agar medium supplemented with heat-inactivated Escherichia coli; however, for the amoebic encystment of Acanthamoeba spp., a defined, slightly modified liquid media is used. In this study, in order to generate pure N. fowleri cysts, a liquid encystment medium (buffer 1) modified from Page’s amoeba saline was applied for encystation of N. fowleri. N. fowleri cysts were well induced after 24 hr with the above defined liquid encystment medium (buffer 1). This was confirmed by observation of a high expression of differential mRNA of nfa1 and actin genes in trophozoites. Thus, this liquid medium can replace the earlier non-nutrient agar medium for obtaining pure N. fowleri cysts. In addition, for cyst formation of Acanthamoeba spp., buffer 2 (adjusted to pH 9.0) was the more efficient medium. To summarize, these liquid encystment media may be useful for further studies which require axenic and pure amoebic cysts.
Acanthamoeba ; Acanthamoeba castellanii ; Actins ; Agar ; Amoeba* ; Desiccation ; Escherichia coli ; Food Supply ; Humans ; Hydrogen-Ion Concentration ; Keratitis ; Meningoencephalitis ; Methods ; Naegleria fowleri ; RNA, Messenger ; Trophozoites

Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.
Acanthamoeba* ; Amoeba ; Dust ; Encephalitis ; Genes, rRNA ; Genetics ; Genotype ; Hygiene ; Immunocompromised Host ; Incidence ; Iran* ; Keratitis ; Parasites* ; Polymerase Chain Reaction ; Prevalence ; Rivers ; Soil ; Trophozoites ; Water

BACKGROUND: Entamoeba histolytica is an important etiologic agent of diarrhea. Globally, it is estimated to infect 40 to 50 million people and cause 40,000 to 100,000 deaths per year. Metronidazole is effective but can cause adverse reactions in certain individuals. In search of alternatives, traditional medicinal plants are being studied. Several plants in Family Simaroubaceae have shown anti-amoebic activity. Quassia amara, a member of this family has not been tested.
OBJECTIVE: To determine the effect of Q. amara crude extract on Entamoeba histolytica in vitro.
METHODS: Initial testing of 104 µg/ml ethanolic bark extract was performed. Counts were made after 72 hours. Three trials in triplicates were performed.
Nine (9) dilutions of extract were then tested (18.8 to 5,00 µg/ml). Test tubes were checked for viable amoeba after 24-hour and 72-hour incubation. Minimum inhibitory concentrations (MIC) were determined for the two incubation periods. At least two trials in triplicates for each dilution were performed. metronidazole served as positive control.
RESULTS: At 104 µg/ml incubated for 72 hours, no viable amoeba was obtained and counted. The MIC after 24 hours was 5,000 µg/ml, while the MIC at 72 hours was 37.5 µg/ml.
CONCLUSION: Q. amara crude extract has inhibitory effects on E. histolycain vitro.

Human ; Male ; Female ; Aged 80 And Over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; Child Preschool ; Infant ; Infant Newborn ; Quassia ; Metronidazole ; Entamoeba Histolytica ; Plants, Medicinal ; Amoeba ; Simaroubaceae ; Microbial Sensitivity Tests ; Diarrhea

Some cases have reported that amebic colitis leads to serious complications that are caused by a misdiagnosis of an inflammatory bowel disease and consequential ill-managed steroid therapy. Therefore, it should be stressed that the differential diagnosis on such a case is very important. Eosinophilic colitis may reveal its presence as diarrhea, abdominal pain, ascites, and eosinophilic deposits in tissues. Therefore, it is highly necessary to make a differential diagnosis to distinguish eosinophilic colitis from other infectious or inflammatory bowel diseases. We report a case of amebic colitis, which was mistakenly diagnosed as eosinophilic colitis and a liver eosinophilic abscess in a young male who complained of bloody diarrhea and right upper quadrant pain. However, the misdiagnosed steroid therapy did not aggravate the progress of the amebic infection.
Abdominal Pain ; Abscess ; Amoeba ; Ascites ; Colitis ; Diagnosis, Differential ; Diagnostic Errors ; Diarrhea ; Dysentery, Amebic ; Eosinophils ; Humans ; Inflammatory Bowel Diseases ; Liver ; Liver Abscess ; Male ; Steroids

Free-living Naegleria fowleri is a causal agent of primary amoebic meningoencephalitis in mainly children and young adults. An nfa1 gene, encoding 360 bp of nucleotides, was cloned from a N. fowleri cDNA library by SEREX method. By immunohistochemistry and a confocal microscope, Nfa1 protein was found in amoebic pseudopods, especially in food-cups, when amoeba was in contact with target cells. When an anti-Nfa1 antibody was added to the coculture system, the cytotoxicity of N. fowleri trophozoites onto target cells was decreased, and the severe morphological destruction of rat microglial cells cocultured with N. fowleri trophozoites was reduced. In a tansfection system, an expression vector with an nfa1 gene was successful transfected into nonpathogenic N. gruberi, and transgenic N. gruberi showed the increasing in vitro cytotoxicity. The siRNA decreased the expression levels of nfa1 mRNA and Nfa1 protein in transfected N. fowleri trophozoites. On the immunization of mice with the rNfa1 protein, the protective immunity of host was induced. Thus, mice showed the prolonged mean survival times in PAM-developed mice. In final, the nfa1 gene and Nfa1 protein play an important role in the pathogenesis of N. fowleri infection.
Amoeba ; Animals ; Child ; Clone Cells ; Coculture Techniques ; Gene Library ; Humans ; Immunization ; Immunohistochemistry ; Meningoencephalitis ; Mice ; Naegleria ; Naegleria fowleri ; Nucleotides ; Rats ; RNA, Messenger ; RNA, Small Interfering ; Survival Rate ; Trophozoites ; Young Adult

PURPOSE:Primary immunodeficiency diseases are disorders in which part of the body's immune system is missing or does not function properly due to intrinsic defects in the immune system. These patients have an increased susceptibility to pulmonary complications as well as primary infections. This study was to investigate pulmonary complications in patients with primary immunodeficiency diseases and characterize their patterns according to specific immune defects. METHODS:We retrospectively reviewed the medical records of 37 different cases of primary immunodeficiency diseases that were admitted to Severance hospital in Seoul between 1990 and 2006. RESULTS:Many patients had a previous history of recurrent respiratory infections and some suffered from pulmonary complications. Eight patients with hypogammaglobulinemia showed peribronchial wall thickening or bronchiectasis, and pneumatoceles or emphysematous changes were characteristic complications in two patients with hyper IgE syndrome. On microbiological examination, various bacteria, including Staphylococcus aureus, Pseudomonas aeroginosa, Streptococcus pneumoniae, were isolated from the hypogammaglobulinemia patients' sputum or ear discharge. In some patients with cell-mediated immune defects, such as chronic granulomatous disease or severe combined immune deficiency, yeast and ameba were isolated from the sputum and bronchial washing fluid respectively. CONCLUSION:Infections account for most of these complications, but the host reaction to infection seems to cause characteristic findings that could be helpful for diagnosis. The physician should be alert for the early diagnosis of children with primary immunodeficiency in order to prevent pulmonary complications.
Agammaglobulinemia ; Amoeba ; Bacteria ; Bronchiectasis ; Child ; Diagnosis ; Ear ; Early Diagnosis ; Granulomatous Disease, Chronic ; Humans ; Immune System ; Immunologic Deficiency Syndromes ; Job Syndrome ; Lung Diseases ; Medical Records ; Pseudomonas ; Respiratory Tract Infections ; Retrospective Studies ; Seoul ; Sputum ; Staphylococcus aureus ; Streptococcus pneumoniae ; Yeasts

PURPOSE:Primary immunodeficiency diseases are disorders in which part of the body's immune system is missing or does not function properly due to intrinsic defects in the immune system. These patients have an increased susceptibility to pulmonary complications as well as primary infections. This study was to investigate pulmonary complications in patients with primary immunodeficiency diseases and characterize their patterns according to specific immune defects. METHODS:We retrospectively reviewed the medical records of 37 different cases of primary immunodeficiency diseases that were admitted to Severance hospital in Seoul between 1990 and 2006. RESULTS:Many patients had a previous history of recurrent respiratory infections and some suffered from pulmonary complications. Eight patients with hypogammaglobulinemia showed peribronchial wall thickening or bronchiectasis, and pneumatoceles or emphysematous changes were characteristic complications in two patients with hyper IgE syndrome. On microbiological examination, various bacteria, including Staphylococcus aureus, Pseudomonas aeroginosa, Streptococcus pneumoniae, were isolated from the hypogammaglobulinemia patients' sputum or ear discharge. In some patients with cell-mediated immune defects, such as chronic granulomatous disease or severe combined immune deficiency, yeast and ameba were isolated from the sputum and bronchial washing fluid respectively. CONCLUSION:Infections account for most of these complications, but the host reaction to infection seems to cause characteristic findings that could be helpful for diagnosis. The physician should be alert for the early diagnosis of children with primary immunodeficiency in order to prevent pulmonary complications.
Agammaglobulinemia ; Amoeba ; Bacteria ; Bronchiectasis ; Child ; Diagnosis ; Ear ; Early Diagnosis ; Granulomatous Disease, Chronic ; Humans ; Immune System ; Immunologic Deficiency Syndromes ; Job Syndrome ; Lung Diseases ; Medical Records ; Pseudomonas ; Respiratory Tract Infections ; Retrospective Studies ; Seoul ; Sputum ; Staphylococcus aureus ; Streptococcus pneumoniae ; Yeasts