scholarly journals Identification of a Naegleria fowleri Membrane Protein Reactive with Anti-Human CD59 Antibody

2006 ◽  
Vol 74 (2) ◽  
pp. 1189-1195 ◽  
Author(s):  
Angela E. Fritzinger ◽  
Denise M. Toney ◽  
Rebecca C. MacLean ◽  
Francine Marciano-Cabral
Keyword(s):  
Regulatory Protein ◽  
Cdna Probe ◽  
Complement Regulatory Protein ◽  
Naegleria Fowleri ◽  
Dna And Rna ◽  
Normal Human ◽  
Nægleria Fowleri ◽  
Human Cd59 ◽  
Complement Lysis ◽  
Primary Amebic Meningoencephalitis

ABSTRACT Naegleria fowleri, the causative agent of primary amebic meningoencephalitis, is resistant to complement lysis. The presence of a complement regulatory protein on the surface of N. fowleri was investigated. Southern blot and Northern blot analyses demonstrated hybridization of a radiolabeled cDNA probe for CD59 to genomic DNA and RNA, respectively, from pathogenic N. fowleri. An 18-kDa immunoreactive protein was detected on the membrane of N. fowleri by Western immunoblot and immunofluorescence analyses with monoclonal antibodies for human CD59. Complement component C9 immunoprecipitated with the N. fowleri “CD59-like” protein from amebae incubated with normal human serum. In contrast, a gene or protein similar to CD59 was not detected in nonpathogenic, complement-sensitive N. gruberi amebae. Collectively, our studies suggest that a protein reactive with antibodies to human CD59 is present on the surface of N. fowleri amebae and may play a role in resistance to lysis by cytolytic proteins.

scholarly journals Synergistic Activities of Azithromycin and Amphotericin B against Naegleria fowleri In Vitro and in a Mouse Model of Primary Amebic Meningoencephalitis

2006 ◽  
Vol 51 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Shannon M. Soltow ◽  
George M. Brenner
Keyword(s):  
Central Nervous System ◽  
Mouse Model ◽  
Amphotericin B ◽  
Fixed Combination ◽  
Central Nervous System Infection ◽  
Naegleria Fowleri ◽  
Combined Use ◽  
Nægleria Fowleri ◽  
Primary Amebic Meningoencephalitis

ABSTRACT Naegleria fowleri is responsible for producing a rapidly fatal central nervous system infection known as primary amebic meningoencephalitis (PAM). To date, amphotericin B, an antifungal agent, is the only agent with established clinical efficacy in the treatment of PAM. However, amphotericin B is not always successful in treating PAM and is associated with severe adverse effects. We previously found azithromycin to be more effective than amphotericin B in a mouse model of PAM. We therefore investigated the combination of amphotericin B and azithromycin in vitro and in a mouse model of PAM. For the in vitro studies, 50% inhibitory concentrations were calculated for each drug alone and for the drugs in fixed combination ratios of 1:1, 3:1, and 1:3. We found amphotericin B and azithromycin to be synergistic at all three of the fixed combination ratios. In our mouse model of PAM, a combination of amphotericin B (2.5 mg/kg of body weight) and azithromycin (25 mg/kg) protected 100% of the mice, whereas amphotericin B alone (2.5 mg/kg) protected only 27% of mice and azithromycin alone (25 mg/kg) protected 40% of mice. This study indicates that amphotericin B and azithromycin are synergistic against the Lee strain of N. fowleri, suggesting that the combined use of these agents may be beneficial in treating PAM.

scholarly journals Eight-Year-Old Male With Primary Amebic Meningoencephalitis

2019 ◽  
Vol 6 (8) ◽  
Author(s):  
Chairut Vareechon ◽  
Thomas Tarro ◽  
Claudia Polanco ◽  
Vikram Anand ◽  
Pia S Pannaraj ◽  
...  
Keyword(s):  
Fresh Water ◽  
Clinical Features ◽  
Hot Spring ◽  
Naegleria Fowleri ◽  
Free Living ◽  
Free Living Amoeba ◽  
Nægleria Fowleri ◽  
Primary Amebic Meningoencephalitis

Abstract Naegleria fowleri is a thermophilic free-living amoeba that is found in warm, fresh water and causes primary amebic meningoencephalitis (PAM). The following report demonstrates the rapid and destructive clinical features of PAM in an 8-year-old male who presented with severe headaches approximately 12 days after swimming in a hot spring.

scholarly journals Successful Treatment of an Adolescent With Naegleria fowleri Primary Amebic Meningoencephalitis

PEDIATRICS ◽  
2015 ◽  
Vol 135 (3) ◽  
pp. e744-e748 ◽  
Author(s):  
W. M. Linam ◽  
M. Ahmed ◽  
J. R. Cope ◽  
C. Chu ◽  
G. S. Visvesvara ◽  
...  
Keyword(s):  
Successful Treatment ◽  
Naegleria Fowleri ◽  
Nægleria Fowleri ◽  
Primary Amebic Meningoencephalitis

scholarly journals Activities of Azithromycin and Amphotericin B against Naegleria fowleri In Vitro and in a Mouse Model of Primary Amebic Meningoencephalitis

2003 ◽  
Vol 47 (2) ◽  
pp. 524-528 ◽  
Author(s):  
Shannon M. Goswick ◽  
George M. Brenner
Keyword(s):  
Amphotericin B ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Naegleria Fowleri ◽  
Nægleria Fowleri ◽  
Free Living Ameba ◽  
Primary Amebic Meningoencephalitis ◽  
Observation Period

ABSTRACT Inhalation of fresh water containing the free-living ameba Naegleria fowleri may lead to a potentially fatal infection known as primary amebic meningoencephalitis. Amphotericin B is the only agent with established clinical efficacy in the treatment of primary amebic meningoencephalitis in humans, but therapy with this drug is often associated with adverse effects on the kidneys and other organs, and not all persons treated with amphotericin B have survived. We investigated the in vitro activity and in vivo efficacy of newer therapeutic agents in an attempt to identify other useful agents for treating primary amebic meningoencephalitis. Azithromycin has shown in vitro activity against Acanthamoeba spp. and in vivo activity against experimental toxoplasmosis. In our study, the MIC of azithromycin against N. fowleri was 13.4 μM (10 μg/ml), which was 123 times greater than the MIC of amphotericin B, which was 0.108 μM (0.1 μg/ml). Azithromycin protected 100% of mice infected with N. fowleri at a dose of 75 mg/kg/day for 5 days, whereas amphotericin B protected only 50% of mice at a dose of 7.5 mg/kg/day for 5 days, and all control mice died during the 28-day observation period. We conclude that azithromycin has both in vitro and in vivo activity versus N. fowleri and may be a useful addition to therapy for primary amebic meningoencephalitis.

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