scholarly journals Draft Chromosome Sequences of a Clinical Isolate of the Free-Living Ameba Naegleria fowleri

2021 ◽  
Vol 10 (15) ◽  
Author(s):  
Ibne Karim M. Ali ◽  
Alyssa Kelley ◽  
Sandeep J. Joseph ◽  
Subin Park ◽  
Shantanu Roy ◽  
...  
Keyword(s):  
Naegleria Fowleri ◽  
Sequencing Data ◽  
Mapping Data ◽  
Pacbio Sequencing ◽  
Free Living ◽  
Illumina Hiseq ◽  
Content Type ◽  
Nægleria Fowleri ◽  
Free Living Ameba ◽  
Primary Amebic Meningoencephalitis

ABSTRACT We present the chromosome sequences of a Naegleria fowleri isolate from a human primary amebic meningoencephalitis (PAM) case. The genome sequences were assembled from Illumina HiSeq and PacBio sequencing data and verified with the optical mapping data. This led to the identification of 37 contigs representing 37 chromosomes in N. fowleri.

scholarly journals Epidemiology and Clinical Characteristics of Primary Amebic Meningoencephalitis Caused by Naegleria fowleri: A Global Review

2020 ◽  
Author(s):  
Radhika Gharpure ◽  
John Bliton ◽  
Alexandra Goodman ◽  
Ibne Karim M Ali ◽  
Jonathan Yoder ◽  
...  
Keyword(s):  
Case Reports ◽  
Water Source ◽  
Case Definition ◽  
Naegleria Fowleri ◽  
Free Living ◽  
Course Of Illness ◽  
Confirmatory Testing ◽  
Nægleria Fowleri ◽  
Free Living Ameba ◽  
Primary Amebic Meningoencephalitis

Abstract Background Primary amebic meningoencephalitis (PAM) is a rapidly progressive and often fatal condition caused by the free-living ameba Naegleria fowleri. To estimate the global occurrence, characterize the epidemiology, and describe the clinical features of PAM, we report a series of PAM cases published in the international literature and reported to the Centers for Disease Control and Prevention (CDC). Methods We performed a literature search of PAM case reports published through 2018. Additionally, we included cases reported through the CDC’s Free-Living Ameba surveillance or diagnosed via CDC’s Free-Living and Intestinal Amebas Laboratory. Cases were classified as confirmed, probable, or suspect on the basis of confirmatory testing, presentation, exposure, and disease course. Results A total of 381 PAM cases were identified. Seven reported survivors were classified as confirmed. The most commonly reported exposure associated with PAM was swimming/diving, and the most common class of water source was lakes/ponds/reservoirs. Patients were predominantly male (75%), with a median age of 14 years. Confirmed and probable cases were similar in their survival, course of illness, and cerebrospinal fluid (CSF) findings. Conclusions PAM is a rare but deadly disease with worldwide occurrence. Improved clinician awareness, resulting in earlier diagnosis and treatment, may contribute to increased survival among PAM patients. The case definition of probable used in this study appears to capture cases of PAM, as evidenced by similarities in outcomes, clinical course, and CSF profile to confirmed cases. In the absence of confirmatory testing, clinicians could use this case definition to identify cases of 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 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.

scholarly journals Effect of a Commercial Disinfectant CLORICAN® on Acanthamoeba spp. and Naegleria fowleri Viability

Parasitologia ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 119-129
Author(s):  
Ines Sifaoui ◽  
Aitor Rizo-Liendo ◽  
María Reyes-Batlle ◽  
Iñigo Arberas-Jiménez ◽  
Rubén L. Rodríguez-Expósito ◽  
...  
Keyword(s):  
Chlorine Dioxide ◽  
Acanthamoeba Keratitis ◽  
Naegleria Fowleri ◽  
Free Living ◽  
Short Period ◽  
Free Living Amoeba ◽  
Swimming Pool Water ◽  
Microbial Proliferation ◽  
Nægleria Fowleri ◽  
Primary Amebic Meningoencephalitis

Swimming pool water treatment by chemicals is an essential step to avoid microbial proliferation and infections namely caused by free living amoeba such as, for example, primary amebic meningoencephalitis and Acanthamoeba keratitis. In the present study, a commercial reactive, CLORICAN, based on chlorine dioxide, was evaluated against Acanthamoeba spp. and Naegleria fowleri. We observed that CLORICAN could eliminate in a short period of incubation time both amoebae. Furthermore, Naegleria fowleri’s trophozoites were more sensitive than those of Acanthamoeba spp. By means of inverted microscopy, the chlorine dioxide was found to greatly affect morphology shape by increasing the cell size shrinkage.

Development of a high- versus low-pathogenicity model of the free-living amoeba Naegleria fowleri

Microbiology ◽  
2012 ◽  
Vol 158 (10) ◽  
pp. 2652-2660 ◽  
Author(s):  
Denise C. Burri ◽  
Bruno Gottstein ◽  
Béatrice Zumkehr ◽  
Andrew Hemphill ◽  
Nadia Schürch ◽  
...  
Keyword(s):  
Naegleria Fowleri ◽  
Free Living ◽  
Free Living Amoeba ◽  
Nægleria Fowleri

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 Naegleria fowleri: Pathogenesis, Diagnosis, and Treatment Options

2015 ◽  
Vol 59 (11) ◽  
pp. 6677-6681 ◽  
Author(s):  
Eddie Grace ◽  
Scott Asbill ◽  
Kris Virga
Keyword(s):  
Case Reports ◽  
Treatment Options ◽  
Clinical Manifestations ◽  
Naegleria Fowleri ◽  
Content Type ◽  
High Profile ◽  
Free Living Amoeba ◽  
Nægleria Fowleri ◽  
Amoebic Meningoencephalitis

ABSTRACTNaegleria fowlerihas generated tremendous media attention over the last 5 years due to several high-profile cases. Several of these cases were followed very closely by the general public.N. fowleriis a eukaryotic, free-living amoeba belonging to the phylum Percolozoa.Naegleriaamoebae are ubiquitous in the environment, being found in soil and bodies of freshwater, and feed on bacteria found in those locations. WhileN. fowleriinfection appears to be quite rare compared to other diseases, the clinical manifestations of primary amoebic meningoencephalitis are devastating and nearly always fatal. Due to the rarity ofN. fowleriinfections in humans, there are no clinical trials to date that assess the efficacy of one treatment regimen over another. Most of the information regarding medication efficacy is based on either case reports orin vitrostudies. This review will discuss the pathogenesis, diagnosis, pharmacotherapy, and prevention ofN. fowleriinfections in humans, including a brief review of all survivor cases in North America.

scholarly journals Vaccination with Lentiviral Vector Expressing thenfa1Gene Confers a Protective Immune Response to Mice Infected with Naegleria fowleri

2013 ◽  
Vol 20 (7) ◽  
pp. 1055-1060 ◽  
Author(s):  
Jong-Hyun Kim ◽  
Hae-Jin Sohn ◽  
Jinyoung Lee ◽  
Hee-Jong Yang ◽  
Yong-Joon Chwae ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Viral Vector ◽  
Lentiviral Vector ◽  
Survival Rates ◽  
Dna Vaccination ◽  
Naegleria Fowleri ◽  
Content Type ◽  
Ifn Γ ◽  
Nægleria Fowleri

ABSTRACTNaegleria fowleri, a pathogenic free-living amoeba, causes fatal primary amoebic meningoencephalitis (PAM) in humans and animals. Thenfa1gene (360 bp), cloned from a cDNA library ofN. fowleri, produces a 13.1-kDa recombinant protein which is located on pseudopodia, particularly the food cup structure. Thenfa1gene plays an important role in the pathogenesis ofN. fowleriinfection. To examine the effect ofnfa1DNA vaccination againstN. fowleriinfection, we constructed a lentiviral vector (pCDH) expressing thenfa1gene. For thein vivomouse study, BALB/c mice were intranasally vaccinated with viral particles of a viral vector expressing thenfa1gene. To evaluate the effect of vaccination and immune responses of mice, we analyzed the IgG levels (IgG, IgG1, and IgG2a), cytokine induction (interleukin-4 [IL-4] and gamma interferon [IFN-γ]), and survival rates of mice that developed PAM. The levels of both IgG and IgG subclasses (IgG1 and IgG2a) in vaccinated mice were significantly increased. The cytokine analysis showed that vaccinated mice exhibited greater IL-4 and IFN-γ production than the other control groups, suggesting a Th1/Th2 mixed-type immune response. In vaccinated mice, high levels of Nfa1-specific IgG antibodies continued until 12 weeks postvaccination. The mice vaccinated with viral vector expressing thenfa1gene also exhibited significantly higher survival rates (90%) after challenge withN. fowleritrophozoites. Finally, thenfa1vaccination effectively induced protective immunity by humoral and cellular immune responses inN. fowleri-infected mice. These results suggest that DNA vaccination using a viral vector may be a potential tool againstN. fowleriinfection.

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