Environmental isolation of Balamuthia mandrillaris associated with a case of amebic encephalitis.
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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 nonnutrient agar with Escherichia coli as a food source) contained, in addition to the ameba, a variety of soil organisms, including other amebas, ciliates, fungi, and nematodes, as contaminants. Presumptive Balamuthia amebas were recognized only after cultures had been kept for several weeks, after they had burrowed into the agar. These were transferred through a succession of nonnutrient agar plates to eliminate fungal and other contaminants. In subsequent transfers, axenic Naegleria amebas and, later, tissue cultures (monkey kidney cells) served as the food source. Finally, the amebas were transferred to cell-free axenic medium. In vitro, the Balamuthia isolate is a slow-growing organism with a generation time of approximately 30 h and produces populations of approximately 2 x 10(5) amebas per ml. It was confirmed as Balamuthia by indirect immunofluorescence staining with rabbit anti-Balamuthia serum and human anti-Balamuthia antibody-containing serum from the amebic encephalitis patient. The environmental isolate is similar in its antimicrobial sensitivities and identical in its 16S ribosomal DNA sequences to the Balamuthia isolate from the deceased patient. (+info)
Molecular characterisation of Neoparamoeba strains isolated from gills of Scophthalmus maximus.
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Small subunit ribosomal RNA gene sequences were determined for 5 amoeba strains of the genus Neoparamoeba Page, 1987 that were isolated from gills of Scophthalmus maximus (Linnaeus, 1758). Phylogenetic analyses revealed that 2 of 5 morphologically indistinguishable strains clustered with 6 strains identified previously as N. pemaquidensis (Page, 1970). Three strains branched as a clade separated from N. pemaquidenis and N. aestuarina (Page, 1970) clades. Our analyses suggest that these 3 strains could be representatives of an independent species. In a more comprehensive eukaryotic tree, strains belonging to Neoparamoeba spp. formed a monophyletic group with a sister-group relationship to Vannella anglica Page, 1980. They did not cluster with Gymnamoebae of the families Hartmannellidae, Flabellulidae, Leptomyxidae or Amoebidae presently available in GenBank. (+info)
Efficacy of saccharomyces boulardii with antibiotics in acute amoebiasis.
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AIM: To compare the efficacy of antibiotics therapy alone with antibiotics and saccharomyces boulardii in treatment of acute amebiasis. METHODS: In a double blind, random clinical trial on patients with acute intestinal amoebiasis, 57 adult patients with acute amoebiasis, diagnosed with clinical manifestations (acute mucous bloody diarrhea) and amebic trophozoites engulfing RBCs found in stool were enrolled in the study. Regimen 1 included metronidazole (750 mg Tid) and iodoquinol (630 mg Tid) for 10 days. Regimen 2 contained capsules of lyophilized saccharomyces boulardii (250 mg Tid) orally in addition to regimen 1. Patients were re-examined at two and four weeks after the treatment, and stool examination was performed at the end of week 4. Student's t-test, chi(2) and McNemar's tests were used for statistical analysis. RESULTS: Three patients refused to participate. The other 54 patients were randomized to receive either regimen 1 or regimen 2 (Groups 1 and 2 respectively, each with 27 patients). The two groups were similar regarding their age, sex and clinical manifestations. In Group 1, diarrhea lasted 48.0+/-18.5 hours and in Group 2, 12.0+/-3.7 hours (P<0.0001). In Group 1, the durations of fever and abdominal pain were 24.0+/-8.8 and 24.0+/-7.3 hours and in Group 2 they were 12.0+/-5.3 and 12.0+/-3.2 hours, respectively (P<0.001). Duration of headache was similar in both groups. At week 4, amebic cysts were detected in 5 cases (18.5 %) of Group 1 but in none of the Group 2 (P<0.02). CONCLUSION: Adding saccharomyces boulardii to antibiotics in the treatment of acute amebiasis seems to decrease the duration of clinical symptoms and cyst passage. (+info)
Prevalence of amebiasis in inflammatory bowel disease in Turkey.
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AIM: To explore the prevalence of amebiasis in inflammatory bowel disease (IBD) in Turkey. METHODS: In this study, amoeba prevalence in 160 cases of IBD, 130 of ulcerative colitis and 30 of Crohn's disease were investigated in fresh faeces by means of wet mount+Lugol's iodine staining, modified formol ethyl acetate and trichrome staining methods and to compare the diagnostic accuracy of wet mount+Lugol's iodine staining, modified formol ethyl acetate and trichrome staining methods in the diagnosis of Entamoeba histolytica (E. histolytica)/ Entamoeba dispar (E. dispar). RESULTS: E. histolytica/E. dispar cysts and trophozoites were found in 14 (8.75 %) of a total of 160 cases, 13 (10.0 %) of the 130 patients with ulcerative colitis and 1 (3.3 %) of the 30 patients with Crohn's disease. As for the 105 patients in the control group who had not any gastrointestinal complaints, 2 (1.90 %) patients were found to have E. histolytica /E. dispar cysts in their faeces. Parasite prevalence in the patient group was determined to be significantly higher than that in the control group (Fischer's Exact Test, P<0.05). When the three methods of determining parasites were compared with one another, the most effective one was found to be trichrome staining method (Kruskal-Wallis Test, P<0.01). CONCLUSION: Consequently, amoeba infections in IBD cases have a greater prevalence compared to the normal population. The trichrome staining method is more effective for the detection of E. histolytica /E. dispar than the wet mount+Lugol's iodine staining, modified formol ethyl acetate methods. (+info)
Immunological characterizations of a cloned 13.1-kilodalton protein from pathogenic Naegleria fowleri.
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We previously cloned an antigenic gene (named nfa1) from a cDNA library of Naegleria fowleri by immunoscreening. The nfa1 gene had a coding nucleotide sequence consisting of 357 bases and produced a recombinant 13.1-kDa protein (Nfa1). In this study, to get more information regarding the recombinant Nfa1 protein (rNfa1), we produced an anti-Nfa1 polyclonal antibody from mice immunized with rNfa1 and used a peroxidase staining method to carry out immunocytochemistry experiments. In addition, we observed the effect of the presence of an anti-Nfa1 antibody on the in vitro cytotoxicity of N. fowleri against Chinese hamster ovary (CHO) cells. Trophozoites of N. fowleri in cultivation reacted strongly with a peroxidase-labeled anti-Nfa1 antibody. In inflammatory and necrotic regions of brain tissue infected with N. fowleri, labeled trophozoites that were stained brown were also observed. When examined using a transmission electron microscope, the Nfa1 protein showed pseudopodium-specific immunolocalization on a trophozoite of N. fowleri. When examined using a light microscope, CHO cells grown in cocultures with N. fowleri trophozoites (group I) for 48 h showed morphologically severe destruction but CHO cells grown in cocultures with N. fowleri trophozoites and an anti-Nfa1 polyclonal antibody (group II) showed less destruction. The results of a lactate dehydrogenase release assay showed that group I CHO cells exhibited 81% cytotoxicity and group II CHO cells exhibited 13.8% cytotoxicity. (+info)
Immunochemical characterisation of a 29-Kda surface-associated molecule of Entamoeba histolytica and its recognition by serum from patients with amoebiasis.
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A 29-Kda cytotoxic molecule of axenically-grown pathogenic Entamoeba histolytica (strain HM1) was purified from an amoebic extract by immuno-affinity chromatography with monoclonal antibodies. Immunoreactivity of the purified 29-Kda molecule altered significantly (p less than 0.01) after exposure to heat or trypsin, but remained unaltered after treatment with sodium metaperiodate. The 29-Kda molecule was recognised by serum from each of 13 patients with amoebic liver abscess. In an ELISA system, the molecule produced significantly higher (p less than 0.01) OD readings with these serum samples than with samples from asymptomatic cyst passers. No serum from healthy subjects or from patients with idiopathic ulcerative colitis or giardiasis had antibodies that reacted with the 29-Kda molecule. The immune response to the 29-Kda amoebic protein in man may indicate a specific role for this molecule in invasive amoebiasis. (+info)
Pleuropulmonary amebiasis.
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Pleuropulmonary amebiasis may be manifest without diarrhea or dysentery.In obscure lesions of the right lower lung field, one should always consider pleuropulmonary amebiasis-especially with low grade fever and moderate leukocytosis. Abscess and empyema contents should be examined promptly microscopically or kept warm to preserve the motility of the trophozoites until satisfactory examination is possible. Conservative therapy will successfully manage most cases of pleuropulmonary amebiasis. If a thorough search fails to reveal Entameba histolytica, and the diagnosis is still entertained, a medical therapeutic trial is in order. (+info)
A SAMPLE SURVEY OF SELECTED AREAS IN AND NEAR LITTLE ROCK, ARKANSAS, TO ASSESS THE PREVALENCE OF ENTAMOEBA HISTOLYTICA.
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Laboratory confirmed clinical amoebiasis was diagnosed among more than 50 persons by the University of Arkansas Medical Center from 1965 to 1961. The presence of this number of patients prompted an investigation into the prevalence of Entamoeba histolytica in four selected areas in and around Little Rock, Arkansas. The results of the study, using a sample survey technique, showed that it is possible to have a seemingly large number of clinically significant cases of amoebiasis in a population without a high prevalence of the parasite. Evidence was also obtained of the beneficial effects of improvements in sanitary facilities, as reflected in the lower amoebic prevalence rate in a 0-4-year age-group from one of the four areas surveyed in which a piped, indoor city-water supply and sewage facilities had been installed six years previously. (+info)