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Naegleria

Page  updated 25/4/03

 

A very common genus of soil and freshwater amoebo-flagellate from the Vahlkampfiid family.  The genus Naegleria has a long history.  It was named by Alexeieff (Alexeieff, 1912), was formerly known as Dimastigamoeba, as its members typically have two flagella, but was originally described as Amoeba gruberi (Schardinger, 1899). Three stages exist the amoeba, the bi-flagellate and the cyst. Much is known about this genus (Marciano-Cabral, 1988) because of its abundance, the problems it can cause in human health, and because it has been used as a model for eukaryotic differentiation.  Much remains to be discovered about its biology however, and its mysteries are compounded by its position as a very early branching eukaryote.  Naegleria has been the subject of a recent excellent review that concentrates on the classification and pathogenicity of the genus (De Jonckheere, 2002).

Naeg1.jpg (106447 bytes)

Figure 1.  This  Naegleria has been compressed under a coverslip to envisage internal detail. Phase contrast microscopy.  Note the centrally located phase dense nucleolus (n). The morphology of the amoebae is usually cylindrical with a contractile rear apparently squeezing cytoplasm forwards in locomotion.  (See Locomotion of Naegleria)

This photomicrograph is of Naegleria pringsheimi (previously known as N. gruberi CCAP 1518/1c) now supplied by ATCC 30875  

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Figure 2.  An early Naegleria gruberi (NEG-M) flagellate, note that the nucleus is positioned closely with the flagellar root.  The entire flagellar structure requires the synthesis of some 200 proteins.   This remarkable transformation takes place within 100 minutes from initiation.   The laboratory of Chandler Fulton has been using Naegleria transformation as a model system for differentiation. (Hoffman optics, magnification same as Figure1).

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Pathogenicity of Naegleria
A few Naegleria species have been shown to be pathogenic in humans and animals most notably N. fowleri.  This amoeba is a facultative pathogen capable of living many generations without infecting a host.  Trophozoites are thought to enter the nose during swimming in warm water and thereafter the brain by locomotion and destruction of neurons. N. fowleri causes Primary Amoebic Meningoencephalitis (PAM) in man Naegleria fowleri posesses secreted proteases (
Ferrante & Bates, 1988), phospholipases (Fulford et al, 1985; Barbour & Marciano-Cabral, 2001), and pore-forming peptides (Herbst et al, 2002), all of which have been implicated in the pathogenic process.  Although man can act as a host, this occurs so infrequently that we are very unlikely to be the primary host.  This host  (if indeed there is one) has not yet been clearly identified, but many any other mammals have been reported to be infected or infectable.  These include; mice, cotton rats, squirrels, muskrats (John & Hope, 1990), guinea pigs (Culbertson et al, 1972), and sheep (Young et al, 1980).  Many wild animals (but not all) have significant titres of Naegleria reactive antibodies suggesting that they come into contact with this group (Kollars & Wilhelm, 1996).  It is possible that  the main host are fish as these are frequently found to be parasitized by Naegleria and other amoebae (especially the gills).  Invertebrates too cannot be ruled out as snails, amphibians and reptiles are also associated with Naegleria (Franke & Mackiewicz, 1982). 

As in other amoebae there is a strong correlation between temperature tolerance and pathogenicity of Naegleria species (Griffin, 1972).  Naturally, any amoeba that lives within a human host must be able to survive the normal 37oC and elevation above this that occurs in disease associated fevers. The majority of human PAM cases are caused by Naegleria fowleri which can grow at temperatures as high as 45oC.  N. fowleri and other temperature tolerant Naegleria sp. multiply in bodies of water both natural and man-made that are warm and most PAM cases where Naegleria is involved have been caused by swimming or other intimate contact with warm waters (De Jonckheere & Van de Voorde, 1977).  However there have been at least three cases have been documented where no association with water has been made (Lawande et al, 1979; Sugita et al, 1999; Shenoy et al, 2002). Naegleria is thought to enter the body through the nose and both pathogenic and non-pathogenic Naegleria has been isolated from the nasal mucosa of non-infected individuals (Cerva et al, 1973; el-Marhoumy et al, 1988). 

Pathogenic Naegleria in the U.K.  

The Interaction of pathogenic Naegleria with host cells.
Both pathogenic (
Chi et al, 1959) and non-pathogenic (Alonso & Zubiaur, 1985) Naegleria phagocytose red blood cells and tissue cultured cells (Cursons & Brown, 1978).  The aggressive phagocytosis seen by Naegleria is accomplished by a specialised feeding apparatus called the "amoebostome", an actin-rich sucker 

Treatment of Primary Amoebic Meningoencephalitis (PAM)
Of the 300 or so cases of this disease world-wide, only seven or so have been survived (
Jain et al, 2002).  The drug of choice has been amphotericin B (Anderson & Jamieson, 1972;Seidel et al, 1982;Jain et al, 2002 ) it is usually given intravenously at 1mg/kg/day (see Shenoy et al, 2002).  In the cases where patients have survived early diagnosis has been crucial.  Symptoms are generally like bacterial meningitis but with no bacteria in the cerebrospinal fluid, the presence of amoebae can however be detected by observation of the CSF under a microscope. The incubation period is usually between 3 and 8 days and the patient usually dies 7-10 days after infection (Butt, 1966; Anderson & Jamieson, 1972; Barnett et al, 1996).  

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Molecular Biology of Naegleria

The nucleus of Naegleria is similar in overall structure to a number of protists in that the nucleolus is very prominent (Figure 1). 

Although the ploidy (how many copies of the genome exist in the nucleus) of Naegleria is not known it is suspected that it is polyploid (Clarke et al, 1990).  There are about 23 chromosomes with total genome of about 104 Mb (Clarke et al, 1990).  The most remarkable thing about the molecular biology of Naegleria is that the rRNA genes are carried on a 14 Kb plasmid present as a multi-copy (4,000) episome! (Clark & Cross, 1987). These circular plasmids are a feature of the Vahlkampfiid amoeba (Clark & Cross, 1988) and are easily isolated from the amoeba (click here for method).

External Naegleria Links:-

Naegleria gruberi mitochondrial genome. David Caprette -Rice University on Naegleria transformation  Charles Walsh - University of Pittsburgh Naegleria page
Francine Marciano-Cabral - Medical College of Virginia CDC Atlanta Georgia Simon Kilvington- University of Leicester
 

Classification of Naegleria species

Many different strains of Naegleria have been isolated and most described as belonging to the N. gruberi groups, however molecular analysis indicates that these are not monophylectic and the genus has now been reclassified into some 24 species (this number will soon expand).  In order to simplify the classification, only the current situation will be discussed based on molecular data (usually 5.8S rDNA or SSUrDNA gene data).  See (De Jonckheere 2002) for details.

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Described strains (and availability):-
N. australiensis (De Jonckheere, 1981) related to N. tihangensis.
N. andersoni (De Jonckheere, 1988) related to N. jamiesoni.
N. carteri (Dobson et al, 1997) No strain available at ATCC or CCAP.
N. clarki (De Jonckheere, 1984) ATCC 30544 sewage effluent, Ohio, 1969
N. chilensis (De Jonckheere et al, 2001). related to N.pussardi.No known flagellar stage
N. fowleri (Carter, 1970
N. fultoni (De Jonckheere et al, 2001) related to N. pringsheimi.
N. galeacystis (De Jonckheere, 1994a)
N. gruberi (Schardinger, 1899)
N. indonesiensis (De Jonckheere et al, 2001) No known flagellar stage
N. italica (De Jonckheere et al, 1984)
N. jadini (Willaert & Le Ray, 1973)
N. jamiesoni (De Jonckheere, 1988)
N. lovaniensis (Stevens et al, 1980) ATCC 30467 domestic water supply, Kadina, Australia, 1972. 
ATCC30569 Bowling Green, OH, 1970.
N. minor (De Jonckheere & Brown 1995) Flagellar stage has four flagella and can divide but only once.
N. morganensis (Dobson et al, 1997)
N. niuginesis (Dobson et al, 1997) No strain available at ATCC or CCAP.
N. pagei (De Jonckheere, 2002)
N. philippinensis (De Jonckheere, 2002)
N. pringsheimi (De Jonckheere, 2002)
N. pussardi (Pernin & De Jonckheere, 1996)
N. robinsoni (De Jonckheere & Brown, 1999)  Type strain NG944 CCAP 1518/19; Flagellar stage has four flagella and can divide but only once to produce a bi-flagellated cell.  This is the same situation as N. minor but there is no relationship by SSUrDNA gene sequence. N.robinsoni is related to N.indonesiensis.
N. sturti (Dobson et al, 1997
N. tihangensis (De Jonckheere, 2002)

 

Parasites of Naegleria

Bacteria.  
Many amoebae are known to harbour bacteria both free in the cytoplasm and contained within vacuoles.  Some bacteria such as those found in Amoeba proteus, and Pelomyxa palustris are commensal and as such appear to be mutually beneficial.  A strain of Naegleria however has been found to contain an intracellular gram-negative bacteria known as "KNic" (
Michel et al, 2000).  This bacteria inhibits the ability to form cysts but not flagellates, presumably a clever ploy to prevent the amoeba from shutting its self down and so to prevent the spread of the bacteria to surrounding Naegleria sp while permitting formation of the flagellate stage which would help the bacteria spread?  Were this to be the case one would expect KNic also to inhibit apoptosis (if this occurs in Naegleria?).  KNic is an odd looking bacteria, looking like a golf ball by SEM and miniature Acanthamoeba cysts in cross section TEM (Michel et al, 2000).  The KNic bacteria could not be cultured on the many media tried but was found to infect a number of other amoebae (Hartmannella, Vahlkampfia, Balamuthia and even Dictyostelium).  KNic was surrounded by an electron translucent region, however no membrane could be seen indicating that the bacteria were free in the amoebal cytoplasm (Michel et al, 2000) presumably bound by some sort of bacterially produced polymer?

Viruses.
Less is known about viral infections in the genus Naegleria. Virus-like particles have described in several strains, and a bacteriophage has been dicovered in association with an obligate bacteria that looks like the KNic bacteria
(Michel et al, 2001).  This phage is named "Neo-Ph/2" due to its similarity to a phage from a bacteria Neochlamydia hartmannellae that infects the amoeba Hartmannella vermiformis (Schmid et al, 2001).

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Relationships to other Heterobosea 

References:-

Ahn, M.-H., Min, D. Y., Im, K. I. & Lee, K. T. (1986) Experimental study on vertical transmission  of immunity against Naegleria fowleri. Yonsei J. Med.Sci. 19, 102-110.

Anderson, K. & Jamieson, A. (1972) Primary amebic meningoencephalitis. Lancet. 1, 2-3.

Band, R. N. & Balamuth, W. (1974) Hemin replaces serum as a growth requirement for Naegleria. Applied Microbiol. 28, 64-65.

Barbour, S. E. & Marciano-Cabral, F. (2001) Naegleria fowleri amoebae express a membrane-associated calcium-independent phospholipase A2. Biochim.Biophys.Acta. 1530, 123-133.

Barnett, N. D., Kaplan, A. M., Hopkin, R. J., Saubolle, M. A. & Rudinsky, M. F. (1996) Primary amoebic meningoencephalitis with Naegleria fowleri: clinical review. Pediatr. Neurol. 15, 230-234.

Butt, C. G. (1966) Primary amebic meningoencephalitis.  N.Engl.J.Med. 274, 1473-1476.

Byers, T. J. (1986) Molecular Biology of DNA in Acamthamoeba, Amoeba, Entamoeba, and NaegleriaInt.Rev.Cytol. 99, 311-341.

Carter, R. F. (1970) Description of Naegleria sp. isolated from two cases of primary amoebic meningoencephalitis, and the experimental pathological changes induced by it. J.Pathol. 100, 217-244.

Cerva, L., Serbus, C. & Skocil, V. (1973) Isolation of limax amoebae from the nasal mucosa of man.  Folia Parasitol. 20, 97-103.

Chi, L., Vogel, J. E. & Shelokov, A. (1959) Selective phagocytosis of nucleated erythrocytes by cytotoxic amebae in cell culture. Science. 130, 1763.

Clark, C. G. & Cross, G. A. M. (1987) rRNA genes of Naegleria gruberi are carried exclusively on a 14-Kilobase-pair plasmid. Mol.Cell Biol. 7, 3027-3031.

Clark, C. G. & Cross, G. A. M. (1988) Small-subunit ribosomal RNA sequence from Naegleria gruberi supports the polyphyletic origin of amoebas. Mol.Biol.Evol. 5, 512-518.

Clark, C. G., Cross, G. A. M. & De Jonckheere, J. F. (1989) Evaluation of evolutionary divergence in the genus Naegleria by analysis of ribosomal DNA plasmid restriction patterns.  Mol.Biochem.Parasitol. 34, 281-296.

Chang, S. L. (1978) Resistance of pathogenic Naegleria to some common physical and chemical agents. App.Environ.Microbiol. 35, 368-375.

Chu, D.-M. T., Ferguson, T. J. & Marciano-Cabral, F. (2000) Protein kinase activation and protein phosphorylation in Naegleria fowleri amebae in response to normal human serum. J.Eukaryot.Microbiol. 47, 40-47.

Corff, S. & Thomas, J. E. (1984) Changes in cAMP levels during the amoeba to flagellate differentiation of Naegleria. Cytobios. 39, 89-100.

Culbertson, C. G., Ensminger, P. W. & Overton, W. M. (1972) Amebic cellulocutaneaous invasion by Naegleria erobia with generalised visceral lesions after sub-cutaneous inoculation. An experimental study in guinea pigs. Am.J.Clin.Pathol. 68, 529.

Cursons, R. T. M. & Brown, T. J. (1978) Use of cell cultivates as an indicator of pathogenicity of free-living amoebae. J.Clin.Pathol. 31, 1-11.

Datta, T. (1979) Effect of organic and inorganic compounds and carbon dioxide in the excystment of soil amoebae. Arch. Protistenk. 121, 155-161.

De Jonckheere, J. F. (1981) Naegleria australiensis sp. nov., another pathogenic Naegleria from water. Protistologica. 17, 423-429.

De Jonckheere, J. F. (1988) Naegleria andersoni n.sp., a cosmopolitan amoeboflagellate, with two subspecies.  Eur. J. Protistol. 23, 327-333.

De Jonckheere, J. F. (1993) A group I intron in the SSUrDNA of some Naegleria spp. Demonstrated by polymerase chain reaction amplification. J.Euk.Microbiol. 40, 179-187.

De Jonckheere, J. F. (1994a) Comparisons of partial SSU-rDNA sequences suggests revisions of species names in the genus Naegleria. Eur.J.Protistol. 30, 333-341.

De Jonckheere, J. F. (1994b) Evidence for the ancestral origin of group 1 introns in the SSurDNA of Naegleria spp. J.Euk.Microbiol. 41, 457-463.

De Jonckheere, J. F. & Brown, S. (1994) Loss of ORF in the SSUrDNA group 1 intron of one Naegleria lineage. Nuc.Acids Res. 22, 3925-3927.

De Jonckheere, J. F. & Brown, S. (1995) Willaerta minor is a species of Naegleria. Evidence that Naegleria flagellates can divide. Eur.J.Protistol. 31, 58-62.

De Jonckheere, J. F. & Brown, S. (1997) Defining new Naegleria spp. using ribosomal DNA sequences. Acta Protozoologica. 36, 273-278.

De Jonckheere, J. F. (1997) The phylogenetic position of the amoebaflagellate Willaertia deduced from SSUrDNA sequences. Eur.J.Protistology. 33, 72-76.

De Jonckheere, J. F., Pernin, P., Scaglia, M. & Michel, R. (1984) A comparative study of 14 strains of Naegleria australiensis demonstrates the existence of a highly pathogenic subspecies : N. australiensis italica n. ssp., J.Protozool. 31, 324-331.

De Jonckheere, J. F., Brown, S. S. & Robinson, B. S. (1997) On the identity of the amoeboflagellates Didascalus thorntoni and Adelphamoeba galeacystis, J.Euk.Microbiol. 44, 52-54.

De Jonckheere, J. F. & Brown, S. (1998) Three different group I introns in the nuclear large subunit ribosomal DNA of the amoeboflagellate Naegleria. Nuc.Acids Res. 26, 456-461.

De Jonckheere, J. F., Brown, S., Dobson, P. J., Robinson, B. S. & Pernin, P. (2001) The amoeba-to-flagellate transformation test is not reliable for the diagnosis of the genus Naegleria. Description of three new Naegleria spp., Protist. 152, 115-121.

De Jonckheere, J. F. & Van de Voorde, H. (1977) The distribution of Naegleria fowleri in man-made thermal waters.  Am.J.Trop.Med.Hyg. 26, 10-15.

De Jonckheere, J. F. (2002). A century of research on the amoeboflagellate genus Naegleria. Acta Protozool. 41, 309-342.

Dobson, P., Robinson, B. & Rowan-Kelly, B. (1997) New thermophilic Naegleria species (Heterolobosea: Vahlkampfiidae) from Australia and Asia: allozyme, morphometric and physiological characterisation. Acta Protozool. 36, 261-271.

Drouin, G., M., M. d. S. & Zuker, M. (1995) The Giardia lamblia actin gene and the phylogeny of eukaryotes. J.Mol.Biol. 41, 841-849.

Einvik, C., Elde, M. & Johansen, S. (1998) Group I twintrons: Genetic elements in myxomycete and schizopyrenid amoeboflagellate ribosomal DNAs, J.Biotechnology. 64, 63-74.

El-Marhouny, S.M., Antonics, S.N. & Warhurst, D.C. (1988) Isolation of oil amoebae from the nasal mucosa of children in Tanta - Egypt. J.Egypt.Soc.Parasitol. 18, 665-670.

Ferrante, A. & Bates, E. J. (1988) Elastase in the pathogenic free-living amoebae Naegleria and Acanthamoeba. Infect.Immun. 56, 3320-3321.

Fields, B. S. (1996) The molecuar ecology of Legionellae. Trends Microbiol. 4, 286-290.

Franke, E.D. & Mackiewicz, J.S. (1982) Isolation of Acanthamoeba and Naegleria from the intestinal contents of freshwater fish and their potential pathogenicity. J.Parasitol. 68, 164-168.

Fulford, D.E., Bradley, S.G. & Marciano-Cabral, F.M. (1985). J.Protozool. 32, 176-180.

Fulton, C. & Lai, E. Y. (1998) Stable intermediates and holdpoints in the rapid differentiation of Naegleria. Exp.Cell Res. 242, 429-438.

Griffin, J. L. (1972) Temperature tolerance of pathogenic and nonpathogenic free-living amoebas. Science. 178, 869-870.

Griffin, J. L. (1983) The pathogenic amoeboflagellate Naegleria fowleri: Environmental isolations, competitors, ecologic interactions, and the flagellate-empty habitat hypothesis. J.Protozool. 30, 403-409.

Han, J. W., Park, J. H., Kim, M. & Lee, J. H. (1997) mRNA for microtubule proteins are specifically colocalized during the sequential formation of basal body, flagella, and cytoskeletal microtubules in the differentiation of Naegleria gruberi J.Cell Biol. 137, 871-879.

Herbst, R., Ott, C., Jacobs, T., Marti, T., Marciano-Cabral, F. & Leippe, M. (2002) Pore-forming Polypeptides of the Pathogenic Protozoon Naegleria fowleri. J. Biol. Chem. 277, 22353-22360.

Jabri, E., Aigner, S. & Cech, T. R. (1997) kinetic and secondary structure analysis of Naegleria andersoni GIR1, a group1 ribozyme whose putative function is site-specific hydrolysis. Biochemistry. 36, 16345-16354.

Jain, R., Prabhaker, S., Modi, M., Bhatia, R. & Sehgal, R. (2002) Naegleria Meningitis: A rare survival. Neurol. India. 50, 470-472.

John, D.T. & Hoppe, K.L. (1990). Susceptibility of wild mammals to infection with Naegleria fowleri. J.Parasitol. 76, 865-868.

Kollars Jr, T. M. & Wilhelm, W. E. (1996) The occurrence of antibodies to Naegleria species in wild mammals. J. Parasitol. 82, 73-77.

Lai, E. Y., Remillard, S. P. & Fulton, C. (1994) A b-tubulin gene of Naegleria encodes a carboxy-terminal tyrosine. J.Mol.Biol. 235, 377-388.

Laverde, A. V. & Brent, M. M. (1980) Simplified soluble media for the axenic cultivation of Naegleria. Protsistologica. 16, 11-15.

Lawande, R. V., John, I., Dobbs, R. H. & Egler, L. J. (1979) A case of primary amebic meningoenchephalitis in Zaria, Nigeria. Am.J.Clin.Pathol. 71, 591-594.

Lowrey, D. M. & McLaughlin, J. (1985) Subcellular distribution of hydrolases in Naegleria fowleri. J.Protozool. 32, 616-621.

Marciano-Cabral, F. (1988) Biology of Naegleria spp.  Microbiol.Rev. 52, 114-133.

Michel, R., Muller, K.-D., Hauroder, B. & Zoller, L. (2000) A coccoid bacterial parasite of Naegleria sp. (Schizopyrenida: Vahlkampfiidae) inhibits cyct formation of its host but not transformation. Acta. Protozool. 39, 199-207.

Michel, R., Schmid, E. N., Gmeiner, G., Muller, K.-D. & Hauroder, B. (2001) Evidence for bacteriophages within gram-negative Cocci - obligate endoparasitic bacteria of Naegleria sp. Acta. Protozool. 40, 229-232.

Napolitano, J. J., Helene Smith, B. & Persico, F. J. (1967) Population size, clones and morphogenesis in Naegleria gruberi. J.Protozool. 14, 108-109.

Napolitano, J. J. & Smith, B.-H. (1975) Nuclear division in the ameboflagellate Adelphamoeba galeacystis. J.Protozool. 22, 196-199.

Nerad, T. A. & Daggett, P.-M. (1979) Starch gel electrophoresis:an effective method for separation of pathogenic and nonpathogenic Naegleria strains. J.Protozool. 26, 613-615.

Pélandakis, M., De Jonckheere, J. F. & Pernin, P. (1998) Genetic variation in the free-living amoeba Naegleria fowleri. App.Environ.Microbiol. 64, 2977-2981.

Pelandakis, M., Serre, S. & Perin, P. (2000) Analysis of the 5.8S rRNA gene and the internal transcribed spacers in Naegleria spp. and in N. fowleri. J.Eukaryot.Microbiol. 47, 116-121.

Preston, T. M. & O'Dell, D. S. (1973) Deuterium oxide-induced reversion of Naegleria gruberi flagellates. J.Gen.Microbiol. 75, 351-361.

Reveiller, F. L., Suh, S.-J., Sullivan, K., Cabanas, P.-A. & Marciano-Cabral, F. (2001) Isolation of a unique membrane protein from Naegleria fowleri. J.Eukaryot.Microbiol. 48, 676-682.

Robinson BS , et al . (1992) Discontinuous genetic variation among mesophilic Naegleria isolates: Further evidence that N. gruberi is not a single species. J. Protozool. 39, 702-712.

Rohr, U., Weber, S., Michel, R., Selenka, F. & Wilhelm, M. (1998) Comparison of free-living amoebae in hot water systems of hospitals with isolates from moist sanitary areas by identifying genera and determining temperature tolerance. App.Environ.Microbiol. 64, 1822-1824.

Ryu, J.-S. & Im, K. I. (1992) The production and characterization of anti-Naegleria fowleri monoclonal antibodies. Korean J. Parasitol. 30, 33-41.

Schmid, E. N., Muller, K.-D. & Michel, A. (2001) Evidence for bacteriophages within Neochlamydia hartmannellae, an obligate endoparasitic bacterium of the free-living amoeba Hartmannella vermiformisInt. J.Endocytob. Cell Res. 14, 115-119.

Schuster, F. (1963) An electron microscopic study of the amoebo-flagellate, Naegleria gruberi (Scardinger). I. The amoeboid and flagellate stages. J.Protozool. 10, 297-313.

Shenoy, S., Wilson, G., Prashanth, H. V., Vidyalakshmi, K., Dhanashree, B. & Bharath, R. (2002) Primary meningoencephalitis by Naegleria fowleri: First reported case from Mangalore, South India. J. Clin. Microbiol. 40, 309-310.

Shin, H.-J., Cho, M.-S., Jung, S.-Y., Kim, H.-I., Park, S., Kim, H.-J. & Im, K.-I. (2001) Molecular cloning and characterization of a gene encoding a 13.1 kDa antigenic protein of Naegleria fowleri. J.Eukaryot.Microbiol. 48, 713-717.

Sparagano, O., Drouet, E., Denoyel, G., Pernin, P. & Ruchaud-Sparagano, M.-H. (1994) Differentaiation of Naegleria fowleri from other species of Naegleria using monoclonal antibodies and the polymerase chain reaction. Trans.Roy.Soc.Trop.Med.Hygiene. 88, 119-120.

Sparagano, O., Guicher, C. & Peyrol, S. (1997) Naegleria fowleri: location of a specific antigen using an immunogold labeling method. Exper.Parasitol. 85, 299-302.

Stevens, A. R., De Jonckheere, J. F. & Willaert, E. (1980) Naegleria lovaniensis new species: isolation and identification of six thermophilic strains of a new species found in association with Naegleria fowleri. Int.J.Parasit. 10, 51-64.

Sugita, Y., Fujii, T., Hayashi, I., Aoki, T., Yokoyama, T., Morimatsu, M., Fukuma, T. & Takamiya, Y. (1999) Primary amebic meningoencephalitis due to Naegleria fowleri : an autopsy case in Japan. Pathology International. 49, 468-470.

Sussman, D. J., Sellers, J. R., Flicker, P., Lai, E. Y., Cannon, E., Szent-Györgyi, A. G. & Fulton, C. (1984) Actin of Naegleria gruberi J.Biol.Chem. 259, 7349-7354.

Wang, A., Band, R. N. & Kopachik, W. (1995) Effects of trifluralin on growth and differentiation of the amoebo-flagellate Naegleria. FEMS microbiol letters. 127, 99-103.

Weekers, P. H. H., Kleyn, J. & Vogels, G. D. (1997) Phylogenetic position of Psalteriomonas lanterna deduced from SSU rDNA sequence. J.Euk.Microbiol. 44, 467-470.

Willaert, E. & Le Ray, D. (1973) Caracteres morphologiques, biologiques et immunochimiques de Naegleria jadini sp. nov. (Amoebidae, Vahlkampfiidae)., Protisological. 9, 417-426.

Young, M. D., Willeart, E., Neal, F. C., Simpson, C. F. & Stevens, A. (1980) Experimental infection of sheep with Naegleria fowleri of human origin., Am.J.Trop.Med.Hyg. 29, 476-477.

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