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P Muchesa, M Leifels, L Jurzik, K B Hoorzook, T G Barnard, C Bartie
Pathogenic free-living amoebae (FLA), such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba species isolated from aquatic environments have been implicated in central nervous system, eye and skin human infections. They also allow the survival, growth and transmission of bacteria such as Legionella, Mycobacteria and Vibrio species in water systems. The purpose of this study was to investigate the co-occurrence of potentially pathogenic FLA and their associated bacteria in hospital water networks in Johannesburg, South Africa...
October 12, 2016: Parasitology Research
Penelope H Dobrowsky, Sehaam Khan, Thomas E Cloete, Wesaal Khan
BACKGROUND: Legionella spp. employ multiple strategies to adapt to stressful environments including the proliferation in protective biofilms and the ability to form associations with free-living amoeba (FLA). The aim of the current study was to identify Legionella spp., Acanthamoeba spp., Vermamoeba (Hartmannella) vermiformis and Naegleria fowleri that persist in a harvested rainwater and solar pasteurization treatment system. METHODS: Pasteurized (45 °C, 65 °C, 68 °C, 74 °C, 84 °C and 93 °C) and unpasteurized tank water samples were screened for Legionella spp...
October 10, 2016: Parasites & Vectors
Claire L Nicholls, Fiona Parsonson, Lawrence Ek Gray, Adele Heyer, Steven Donohue, Greg Wiseman, Robert Norton
Primary amoebic meningoencephalitis (PAM) is a fulminant, diffuse haemorrhagic meningoencephalitis caused by Naegleria fowleri, with an almost invariably fatal outcome. In Australia and the developed world, PAM remains a rare disease, although it is very likely that large numbers of cases go undetected in developing countries. N. fowleri is a thermophilic, free-living amoeba with a worldwide distribution. It is acquired when contaminated fresh water is flushed into the nose and penetrates the central nervous system via the cribriform plate...
October 3, 2016: Medical Journal of Australia
Tomáš Tyml, Kateřina Skulinová, Jan Kavan, Oleg Ditrich, Martin Kostka, Iva Dyková
The diversity of heterolobosean amoebae, important members of soil, marine and freshwater microeukaryote communities in the temperate zones, is greatly under-explored in high latitudes. To address this imbalance, we studied the diversity of this group of free-living amoebae in the Arctic and the Antarctic using culture dependent methods. Eighteen strain representatives of three heterolobosean genera, Allovahlkampfia Walochnik et Mulec, 2009 (1 strain), Vahlkampfia Chatton et Lalung-Bonnaier, 1912 (2) and Naegleria Alexeieff, 1912 (15) were isolated from 179 samples of wet soil and fresh water with sediments collected in 6 localities...
August 28, 2016: European Journal of Protistology
Ruqaiyyah Siddiqui, Ibne Karim M Ali, Jennifer R Cope, Naveed Ahmed Khan
Naegleria fowleri is a protist pathogen that can cause lethal brain infection. Despite decades of research, the mortality rate related with primary amoebic meningoencephalitis owing to N. fowleri remains more than 90%. The amoebae pass through the nose to enter the central nervous system killing the host within days, making it one of the deadliest opportunistic parasites. Accordingly, we present an up to date review of the biology and pathogenesis of N. fowleri and discuss needs for future research against this fatal infection...
September 9, 2016: Acta Tropica
Jennifer R Cope, Ibne K Ali
Primary amebic meningoencephalitis (PAM) is a devastating infection of the brain caused by the thermophilic free-living ameba, Naegleria fowleri. Infection can occur when water containing the ameba enters the body through the nose, usually during recreational water activities such as swimming or diving. Historically, in the USA, cases were mostly reported from the warmer southern-tier states. In the last 5 years, several notable changes have been documented in PAM epidemiology including a northward expansion of infections and new types of water exposures...
September 2016: Current Infectious Disease Reports
Sutherland K Maciver
While some amoebae reproduce sexually, many amoebae (e.g., Acanthamoeba, Naegleria) reproduce asexually and therefore, according to popular doctrine, are likely to have been genetically disadvantaged as a consequence. In the absence of sex, mutations are proposed to accumulate by a mechanism known as Muller's ratchet. I hypothesise that amoebae can escape the ravages of accumulated mutation by virtue of their being polyploid. The polyploid state reduces spontaneous mutation accumulation by gene conversion, the freshly mutated copy being corrected by the presence of the many other wild-type copies...
September 3, 2016: Trends in Parasitology
Süleyman Yazar, Esra Gürbüz, Mehmet Fatih Sönmez, Ülfet Çetinkaya, Salih Kuk
Free-living amoebae (FLA) are found widely in soil and water in the nature. Among them in which potentially pathogenic for humans and animals are known as "potential pathogenic free-living amoebae (PPFLA)". PPFLA are characterized as the causes of clinical manifestations leading to death especially in immunosuppressed people. Four genus of PPFLA (Acanthamoeba, Naegleria, Balamuthia and Sappinia) are known to be pathogenic to humans. The aims of this study were to investigate the presence of PPFLA in the water supplies in Turkey and to determine their in vivo pathogenicity...
July 2016: Mikrobiyoloji Bülteni
J Jeffrey Pugh, Rebecca A Levy
Primary amoebic meningoencephalitis (PAM) is a very rare disease with a high mortality rate. PAM is caused by Naegleria fowleri, an amoeba which resides in freshwater lakes and ponds and can survive in inadequately chlorinated pools ( Lopez, C.; Budge, P.; Chen, J., et al. Primary amebic meningoencephalitis: a case report and literature review . Pediatr. Emerg. Care 2012 , 28 , 272 - 276 ). In the past 50 years, there have been over 130 cases of Naegleria induced PAM in the United States with only three known survivors; one survivor was diagnosed and treated at Arkansas Children's Hospital...
September 21, 2016: ACS Chemical Neuroscience
Claire Bertelli, Ousmane H Cissé, Brigida Rusconi, Carole Kebbi-Beghdadi, Antony Croxatto, Alexander Goesmann, François Collyn, Gilbert Greub
Recently, a new Chlamydia-related organism, Protochlamydia naegleriophila KNic, was discovered within a Naegleria amoeba. To decipher the mechanisms at play in the modeling of genomes from the Protochlamydia genus, we sequenced the full genome of Pr. naegleriophila, which includes a 2,885,090 bp chromosome and a 145,285 bp megaplasmid. For the first time within the Chlamydiales order, we describe the presence of a clustered regularly interspaced short palindromic repeats (CRISPR) system, the immune system of bacteria, located on the chromosome...
2016: Genome Biology and Evolution
Celsus Sente, Joseph Erume, Irene Naigaga, Julius Mulindwa, Sylvester Ochwo, Phillip Kimuda Magambo, Benigna Gabriela Namara, Charles Drago Kato, George Sebyatika, Kevin Muwonge, Michael Ocaido
BACKGROUND: Pathogenic water dwelling protozoa such as Acanthamoeba spp., Hartmannella spp., Naegleria spp., Cryptosporidium spp. and Giardia spp. are often responsible for devastating illnesses especially in children and immunocompromised individuals, yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers, public health officials and medical practitioners. The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba (FLA), Cryptosporidium and Giardia in Queen Elizabeth Protected Area (QEPA)...
2016: Infectious Diseases of Poverty
Abdul Mannan Baig
Naegleria fowleri causes one of the most devastating necrotic meningoencephalitis in humans. The infection caused by this free-living amoeba is universally fatal within a week of onset of the signs and symptoms of the disease called primary amoebic meningoencephalitis (PAM). In all the affected patients, there is always a history of entry of water into the nose. Even though the diagnostic and treatment protocols have been revised and improved, the obstinate nature of the disease can be gauged by the fact that the mortality rate has persisted around ∼95% over the past 60 years...
August 17, 2016: ACS Chemical Neuroscience
Agnes Thiane Pereira Machado, Marcio Silva, Jorge Iulek
Naegleria gruberi had its genome sequenced by Fritz-Laylin and collaborators in 2010. It is not pathogenic, but has characteristics similar to those of Naegleria fowleri, opportunistic pathogen that can cause fatal encephalitis in humans. N. gruberi genome has contributed to a better understanding of the primitive eukaryotic metabolism and revealed the complexity of several metabolic pathways. In this paper we describe the expression, purification, enzyme characterization and crystallization of N. gruberi GAPDH, the first one for an organism belonging to phylum Percolozoa...
November 2016: Protein Expression and Purification
Moisés Martínez-Castillo, Roberto Cárdenas-Zúñiga, Daniel Coronado-Velázquez, Anjan Debnath, Jesús Serrano-Luna, Mineko Shibayama
It has been 50 years since the first case of primary amoebic meningoencephalitis (PAM) an acute and rapidly fatal disease of the central nervous system (CNS) was reported in Australia. It is now known that the etiological agent of PAM is Naegleria fowleri, an amoeba that is commonly known as "the brain-eating amoeba". N. fowleri infects humans of different ages which are in contact with contaminated water with this microorganism. N. fowleri is distributed worldwide and is found growing in bodies of freshwater in tropical and subtropical environments...
July 4, 2016: Journal of Medical Microbiology
Reena Leeba Richard, Init Ithoi, Mohamad Azlan Abd Majid, Wan Yusoff Wan Sulaiman, Tian Chye Tan, Veeranoot Nissapatorn, Yvonne Ai Lian Lim
The occurrence of waterborne parasites coupled with water parameters at various processing sites of two drinking water treatment plants (A and B) and seven distribution system (DS) sites in Sarawak, Malaysia were studied. Ten liters of water underwent immunomagnetic separation (IMS) technique to detect the presence of Giardia and Cryptosporidium (oo)cysts. The remaining supernatant was used to detect other parasites whilst 50 mL of water sample was each used in the detection of free-living amoebae and fecal coliforms...
2016: International Journal of Environmental Research and Public Health
Esta Tamanaha, Shengxi Guan, Katherine Marks, Lana Saleh
The ten-eleven translocation (TET) proteins catalyze oxidation of 5-methylcytosine ((5m)C) residues in nucleic acids to 5-hydroxymethylcytosine ((5hm)C), 5-formylcytosine ((5f)C), and 5-carboxycytosine ((5ca)C). These nucleotide bases have been implicated as intermediates on the path to active demethylation, but recent reports have suggested that they might have specific regulatory roles in their own right. In this study, we present kinetic evidence showing that the catalytic domains (CDs) of TET2 and TET1 from mouse and their homologue from Naegleria gruberi, the full-length protein NgTET1, are distributive in both chemical and physical senses, as they carry out successive oxidations of a single (5m)C and multiple (5m)C residues along a polymethylated DNA substrate...
August 3, 2016: Journal of the American Chemical Society
Bertha Ayi
This chapter is unique in its focus on infections that are acquired in water. For those who like to swim and spend time in water parks and pools, the exposure to water and therefore the risk of infection is higher. Recreational water illnesses are illnesses related to recreation in water. Of these recreational water illnesses, infections are the most common because water laden with microorganisms or contaminated by human activity gains access to healthy tissue through the skin and body orifices. Infection occurs by inhalation, ingestion, or direct invasion of the respiratory and gastrointestinal tract...
December 2015: Microbiology Spectrum
Jong-Hyun Kim, Hae-Jin Sohn, Jong-Kyun Yoo, Heekyoung Kang, Gi-Sang Seong, Yong-Joon Chwae, Kyongmin Kim, Sun Park, Ho-Joon Shin
Naegleria fowleri, known as the brain-eating amoeba, causes acute primary amoebic meningoencephalitis. During swimming and other recreational water activities, N. fowleri trophozoites penetrate the nasal mucosa and invade the olfactory bulbs, resulting in intense inflammatory reactions in the forebrain tissue. To investigate what kinds of inflammasome molecules are expressed in target cells due to N. fowleri infection, human macrophage cells (THP-1 cells) were cocultured with N. fowleri trophozoites in a noncontact system, and consequently, interleukin-1β (IL-1β) production was estimated...
September 2016: Infection and Immunity
A Contis-Montes de Oca, M Carrasco-Yépez, R Campos-Rodríguez, J Pacheco-Yépez, P Bonilla-Lemus, J Pérez-López, S Rojas-Hernández
Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack...
August 2016: Parasite Immunology
Richard O Johnson, Jennifer R Cope, Marvin Moskowitz, Amy Kahler, Vincent Hill, Kaleigh Behrendt, Louis Molina, Kathleen E Fullerton, Michael J Beach
On June 17, 2015, a previously healthy woman aged 21 years went to an emergency department after onset of headache, nausea, and vomiting during the preceding 24 hours. Upon evaluation, she was vomiting profusely and had photophobia and nuchal rigidity. Analysis of cerebrospinal fluid was consistent with meningitis.* She was empirically treated for bacterial and viral meningoencephalitis. Her condition continued to decline, and she was transferred to a higher level of care in another facility on June 19, but died shortly thereafter...
2016: MMWR. Morbidity and Mortality Weekly Report
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