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Frontiers in Microbiology 2024
PubMed: 38741744
DOI: 10.3389/fmicb.2024.1401217 -
Journal of Parasitic Diseases :... Dec 2017Free-living amoebae (FLA) are a group of protozoa with the capabilities of growth in the environment and invasion to the human body which have been isolated from... (Review)
Review
Free-living amoebae (FLA) are a group of protozoa with the capabilities of growth in the environment and invasion to the human body which have been isolated from different water sources. , , and are the most important FLA. These cause a variety of severe complications of eye and central nervous system. Despite the fact that various studies have demonstrated the prevalence of FLA in different parts of Iran, there is no comprehensive evaluation and conclusion regarding the pollution of various water sources in Iran. This review was carried out to achieve the prevalence pattern of FLA in water resources across Iran to design appropriate health strategies. For this purpose, 8 online databases in English and Persian and also graduate thesis and national parasitology congresses were studied. The key words such as "water resources", "water" and "Iran" were used to search articles between 1990 to 2017. From a total of 236 articles found, 38 reliable articles were included in the study. From the total number of investigated studies, the estimated prevalence was obtained as 36% among 2430 samples. Although prevalence has been considered as a priority, most kinds of free-living amoebae were found in all kinds of water resources. Due to the lack of free-living amoebae prevalence in more than a quarter of the Iranian provinces, more studies are recommended to achieve a better perspective to make comprehensive decisions to improve the hygiene of water resources.
PubMed: 29114120
DOI: 10.1007/s12639-017-0950-2 -
Seminars in Neurology Sep 2005Parasitic infection of the nervous system can produce a variety of symptoms and signs. Because symptoms of infection are often mild or nonspecific, diagnosis can be... (Review)
Review
Parasitic infection of the nervous system can produce a variety of symptoms and signs. Because symptoms of infection are often mild or nonspecific, diagnosis can be difficult. Familiarity with basic epidemiological characteristics and distinguishing radiographic findings can increase the likelihood of detection and proper treatment of parasitic infection of the nervous system. This article discusses the clinical presentation, diagnosis, and treatment for some of the more common infections of the nervous system caused by cestodes, trematodes and protozoans: Echinococcus spp., Spirometra spp. (sparganosis), Paragonimus spp., Schistosoma spp., Trypanosoma spp., Naegleria fowlerii, Acanthamoeba histolytica, and Balamuthia mandrillaris.
Topics: Animals; Cestode Infections; Humans; Nervous System Diseases; Protozoan Infections; Trematode Infections
PubMed: 16170739
DOI: 10.1055/s-2005-917663 -
Antimicrobial Agents and Chemotherapy Jun 2022Infection with pathogenic free-living amoebae, including Naegleria fowleri, spp., and Balamuthia mandrillaris, can lead to life-threatening illnesses, primarily because...
Infection with pathogenic free-living amoebae, including Naegleria fowleri, spp., and Balamuthia mandrillaris, can lead to life-threatening illnesses, primarily because of catastrophic central nervous system involvement. Efficacious treatment options for these infections are lacking, and the mortality rate due to infection is high. Previously, we evaluated the N. fowleri glucokinase (Glck) as a potential target for therapeutic intervention, as glucose metabolism is critical for viability. Here, we extended these studies to the glucokinases from two other pathogenic free-living amoebae, including Acanthamoeba castellanii (Glck) and (Glck). While these enzymes are similar (49.3% identical at the amino acid level), they have distinct kinetic properties that distinguish them from each other. For ATP, Glck and Glck have apparent values of 472.5 and 41.0 μM, while Homo sapiens Glck (Glck) has a value of 310 μM. Both parasite enzymes also have a higher apparent affinity for glucose than the human counterpart, with apparent values of 45.9 μM (Glck) and 124 μM (Glck) compared to ~8 mM for Glck. Additionally, Glck and Glck differ from each other and other Glcks in their sensitivity to small molecule inhibitors, suggesting that inhibitors with pan-amoebic activity could be challenging to generate.
Topics: Acanthamoeba; Amebiasis; Amoeba; Balamuthia mandrillaris; Glucokinase; Humans; Naegleria fowleri
PubMed: 35604214
DOI: 10.1128/aac.02373-21 -
Clinical Microbiology Reviews Jul 2008Balamuthia mandrillaris is an emerging protozoan parasite, an agent of granulomatous amoebic encephalitis involving the central nervous system, with a case fatality rate... (Review)
Review
Balamuthia mandrillaris is an emerging protozoan parasite, an agent of granulomatous amoebic encephalitis involving the central nervous system, with a case fatality rate of >98%. This review presents our current understanding of Balamuthia infections, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of Balamuthia that may be potential targets for therapeutic interventions and/or for the development of preventative measures.
Topics: Animals; Humans; Life Cycle Stages; Lobosea; Protozoan Infections
PubMed: 18625680
DOI: 10.1128/CMR.00056-07 -
Cureus Mar 2021Meningoencephalitis caused by free-living amoebas (FLA) has a high mortality rate, and most treatments are ineffective. FLA includes Naegleria, Fowleri, Acanthamoeba,... (Review)
Review
Meningoencephalitis caused by free-living amoebas (FLA) has a high mortality rate, and most treatments are ineffective. FLA includes Naegleria, Fowleri, Acanthamoeba, and Balamuthia mandrillaris (M). We explore the use of miltefosine in the treatment of one of these infections. The concerning mortality of the infection obligates us to look for more effective treatments for meningoencephalitis caused by FLA. During this review, we will consolidate the knowledge of using miltefosine in these three infections. We will investigate the mechanism by which the drug is effective in these infections as well. After this comprehensive review, we should assess if miltefosine improves the mortality and prognosis of the infection with the information collected. We used a Medical Subject Headings (MeSH) search on PubMed. Inclusion criteria included papers written in the English language and human subjects research for the past 25 years. Until today, there are no definitive guidelines to be followed when treating such patients. However, miltefosine has demonstrated promising results. Miltefosine decreases the usual mortality rate in the three infections; however, there are few reports due to the low frequency of these infections. Almost all cases we documented have survived. More information needs to be gathered for the use of miltefosine for these infections.
PubMed: 33833918
DOI: 10.7759/cureus.13698 -
Clinical Microbiology Reviews Jul 2002Free-living amebas are widely distributed in soil and water, particularly members of the genera Acanthamoeba and NAEGLERIA: Since the early 1960s, they have been... (Review)
Review
Free-living amebas are widely distributed in soil and water, particularly members of the genera Acanthamoeba and NAEGLERIA: Since the early 1960s, they have been recognized as opportunistic human pathogens, capable of causing infections of the central nervous system (CNS) in both immunocompetent and immunocompromised hosts. Naegleria is the causal agent of a fulminant CNS condition, primary amebic meningoencephalitis; Acanthamoeba is responsible for a more chronic and insidious infection of the CNS termed granulomatous amebic encephalitis, as well as amebic keratitis. Balamuthia sp. has been recognized in the past decade as another ameba implicated in CNS infections. Cultivation of these organisms in vitro provides the basis for a better understanding of the biology of these amebas, as well as an important means of isolating and identifying them from clinical samples. Naegleria and Acanthamoeba can be cultured axenically in cell-free media or on tissue culture cells as feeder layers and in cultures with bacteria as a food source. Balamuthia, which has yet to be isolated from the environment, will not grow on bacteria. Instead, it requires tissue culture cells as feeder layers or an enriched cell-free medium. The recent identification of another ameba, Sappinia diploidea, suggests that other free-living forms may also be involved as causal agents of human infections.
Topics: Acanthamoeba; Amebiasis; Amoeba; Animals; Culture Media; Humans; Mice; Naegleria; Opportunistic Infections; Parasitology
PubMed: 12097243
DOI: 10.1128/CMR.15.3.342-354.2002 -
Modern Pathology : An Official Journal... Jan 2020The following discussion deals with three emerging infection diseases that any dermatopathologist working in the northern hemisphere can come across. The first subject... (Review)
Review
The following discussion deals with three emerging infection diseases that any dermatopathologist working in the northern hemisphere can come across. The first subject to be dealt with is gnathostomiasis. This parasitic disease is produced by the third larvarial stage of the parasite that in most patients is associated with the ingestion of raw fish. Epidemiologically, it is most commonly seen in South East Asia, Japan, China, and the American continent, mainly in Mexico, Ecuador, and Peru. Nowadays, the disease is also seen in travelers living in the developed countries who recently came back from visiting endemic countries. The disease produces a pattern of migratory panniculitis or dermatitis with infiltration of eosinophils in tissue. The requirements for making the diagnosis are provided, including clinical forms, common histological findings on skin biopsy as well as the use of ancillary testing. Buruli ulcer, a prevalent mycobacterial infection in Africa, is described from the clinical and histopathological point of view. The disease has been described occasionally in Central and South America as well as in developed countries such as Australia and Japan; Buruli ulcer has also been described in travelers returning from endemic areas. Clinically, the disease is characterized by large, painless ulcerations with undermined borders. Systemic symptoms are usually absent. Classical histological findings include a particular type of fat necrosis and the presence of abundant acid fast bacilli in tissue. Such findings should raise the possibility of this disease, with the purpose of early therapeutically intervention. Lastly, the infection by free living ameba Balamuthia mandrillaris, an emerging condition seen in the US and Peru, is extensively discussed. Special attention is given to clinical and histological characteristics, as well as to the clues for early diagnosis and the tools available for confirmation.
Topics: Amebiasis; Balamuthia mandrillaris; Biopsy; Buruli Ulcer; Communicable Diseases, Emerging; Diagnosis, Differential; Gnathostomiasis; Host-Parasite Interactions; Humans; Predictive Value of Tests; Skin; Skin Diseases
PubMed: 31685961
DOI: 10.1038/s41379-019-0399-1 -
Case Reports in Infectious Diseases 2019is a rare cause of granulomatous meningoencephalitis associated with high mortality. We report a 69-year-old Caucasian female who presented with a 3-day history of...
is a rare cause of granulomatous meningoencephalitis associated with high mortality. We report a 69-year-old Caucasian female who presented with a 3-day history of worsening confusion and difficulty with speech. On admission, she was disoriented and had expressive dysphasia. Motor examination revealed a right arm pronator drift. Cerebellar examination showed slowing of finger-nose testing on the left. She was HIV-negative, but the absolute CD4 count was low. Neuroimaging showed three cavitary, peripherally enhancing brain lesions, involving the right frontal lobe, the left basal ganglia, and the left cerebellar hemisphere. She underwent right frontal craniotomy with removal of tan, creamy, partially liquefied necrotic material from the brain, consistent with granulomatous amoebic encephalitis on tissue staining. Immunohistochemical studies and PCR tests confirmed infection with . She was started on pentamidine, sulfadiazine, azithromycin, fluconazole, flucytosine, and miltefosine. The postoperative course was complicated by an ischemic stroke, and she died a few weeks later.
PubMed: 30838148
DOI: 10.1155/2019/9315756 -
Journal of Clinical Microbiology Jul 2017spp. and are causative agents of granulomatous amoebic encephalitis (GAE), while causes primary amoebic meningoencephalitis (PAM). PAM is an acute infection that... (Review)
Review
spp. and are causative agents of granulomatous amoebic encephalitis (GAE), while causes primary amoebic meningoencephalitis (PAM). PAM is an acute infection that lasts a few days, while GAE is a chronic to subacute infection that can last up to several months. Here, we present a literature review of 86 case reports from 1968 to 2016, in order to explore the affinity of these amoebae for particular sites of the brain, diagnostic modalities, treatment options, and disease outcomes in a comparative manner.
Topics: Amebiasis; Balamuthia mandrillaris; Brain; Central Nervous System Infections; Diagnostic Tests, Routine; Humans; Naegleria fowleri; Treatment Outcome
PubMed: 28404683
DOI: 10.1128/JCM.02300-16