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Boletin Medico Del Hospital Infantil de... 2022Amoebiasis is an intestinal parasitosis caused by the protozoan Entamoeba histolytica that represents the third leading cause of mortality due to parasitosis. It is a...
Amoebiasis is an intestinal parasitosis caused by the protozoan Entamoeba histolytica that represents the third leading cause of mortality due to parasitosis. It is a prevalent disease in tropical climate regions with poor or absent sanitary services. Microscopy and antigen detection techniques are routinely used to diagnose amoebiasis because of their low cost and ease of application. However, these techniques do not differentiate E. histolytica infections and other potentially pathogenic species such as Entamoeba moshkovskii or Entamoeba bangladeshi. Therefore, in the last decades, molecular tests that allow correct identification of the causal agent of amoebiasis and the establishment of the prevalence of the infecting species have been developed. Techniques based on nucleic acids, such as conventional, multiplex, or real-time polymerase chain reaction (PCR), are being seriously considered in clinical laboratories, because they detect the etiologic agent directly from the sample without the need for previous prolonged culture, thus reducing diagnostic time. Also, the nested PCR test and the sequencing of ribosomal markers have allowed the identification of new parasitic species in humans, such as E. moshkovskii and E. bangladeshi, and an improved characterization of the known infecting species. The application of multiplex platforms allows the simultaneous identification of infecting species, increasing the sensitivity and specificity of these techniques. Therefore, the molecular diagnosis of amoebiasis is projected as an innovative tool in the fight against this parasitosis.
Topics: Amebiasis; Entamoeba; Entamoeba histolytica; Entamoebiasis; Feces; Humans
PubMed: 35086128
DOI: 10.24875/BMHIM.21000044 -
Parasites & Vectors Jan 2012Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba... (Review)
Review
Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amebiasis; Encephalitis
PubMed: 22229971
DOI: 10.1186/1756-3305-5-6 -
Annals of Parasitology 2018Amoebas from the genus Acanthamoeba are cosmopolitan organisms, which can exist as free-living organisms and as parasites within host tissue. Acanthamoeba infection... (Review)
Review
Amoebas from the genus Acanthamoeba are cosmopolitan organisms, which can exist as free-living organisms and as parasites within host tissue. Acanthamoeba infection present a serious risk to human health and are characterized by high mortality, especially in immunocompromised individuals. These protozoa are the etiological factors of granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). They can also live in the lungs, adrenals glands, nose, throat, and bones of the host. Furthermore, the amoebas can be vectors of pathogenic bacteria. Acanthamoeba infection caused is a serious clinical problem mainly due to limited progress in diagnostics and treatment of this infection, which is associated with insufficient knowledge of pathogenesis, pathophysiology and the host immune response against Acanthamoeba antigens. This review study presents the biology of Acanthamoeba sp. as well as pathogenicity, diagnostics, and treatment of amoebas infections. It also presents data, including experimental results, concerning pathogenic properties and the host’s immunology response against Acanthamoeba sp.
Topics: Acanthamoeba; Amebiasis; Humans; Immunocompromised Host
PubMed: 30720249
DOI: 10.17420/ap6404.164 -
Revista Medica de Chile May 2013The description of Entamoeba dispar, and the recovery of Entamoeba moshkovskii from humans had a major impact in the epidemiology and clinical management of amebiasis.... (Review)
Review
The description of Entamoeba dispar, and the recovery of Entamoeba moshkovskii from humans had a major impact in the epidemiology and clinical management of amebiasis. Infections range from asymptomatic colonization to hemorrhagic colitis and extra-intestinal diseases. Only a minority of amebiasis patients progress to the development of disease. Recent studies suggest that susceptibility to infection, and its outcome is influenced by the host, parasite genotype, and environment. The identification of Entamoeba histolytica is based on the detection of specific antigens by ELISA and DNA in stool and other clinical samples. Several diagnostic tests have been developed, including polymerase chain reaction, the technique of choice, for the detection and differentiation of E. histolytica, E. dispar, and E. moshkovskii. Combination of serologic tests with detection of the parasite DNA by PCR or antigen by ELISA offers the best approach to diagnosis. However, these techniques are impractical for clinical laboratories of developing countries. Clinicians must follow the guidelines of the World Health Organization to avoid unnecessary treatments. This review describes and discusses recent advances in amebiasis with emphasis in the clinical aspects and management of infection.
Topics: Amebiasis; DNA, Protozoan; Entamoeba histolytica; Enzyme-Linked Immunosorbent Assay; Feces; Host-Parasite Interactions; Humans; Polymerase Chain Reaction
PubMed: 24089276
DOI: 10.4067/S0034-98872013000500009 -
Research in Microbiology 2011Entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. Understanding the genome and... (Review)
Review
Entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. Understanding the genome and evolution of the parasite will help explain how, when and why it causes disease. Here we review current knowledge about the evolutionary genomics of Entamoeba: how differences between the genomes of different species may help explain different phenotypes, and how variation among E. histolytica parasites reveals patterns of population structure. The imminent expansion of the amount genome data will greatly improve our knowledge of the genus and of pathogenic species within it.
Topics: Dysentery, Amebic; Entamoeba histolytica; Evolution, Molecular; Genome, Protozoan; Humans; Intestine, Large; Trophozoites
PubMed: 21288488
DOI: 10.1016/j.resmic.2011.01.007 -
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 -
PLoS Pathogens Oct 2016Amebiasis is caused by Entamoeba histolytica infection and can produce a broad range of clinical signs, from asymptomatic cases to patients with obvious symptoms. The... (Review)
Review
Amebiasis is caused by Entamoeba histolytica infection and can produce a broad range of clinical signs, from asymptomatic cases to patients with obvious symptoms. The current epidemiological and clinical statuses of amebiasis make it a serious public health problem worldwide. The Entamoeba life cycle consists of the trophozoite, the causative agent for amebiasis, and the cyst, the form responsible for transmission. These two stages are connected by "encystation" and "excystation." Hence, developing novel strategies to control encystation and excystation will potentially lead to new measures to block the transmission of amebiasis by interrupting the life cycle of the causative agent. Here, we highlight studies investigating encystation using inhibitory chemicals and categorize them based on the molecules inhibited. We also present a perspective on new strategies to prevent the transmission of amebiasis.
Topics: Amebiasis; Entamoeba; Humans
PubMed: 27764256
DOI: 10.1371/journal.ppat.1005845 -
BMC Infectious Diseases Apr 2022Amoebiasis is caused by the protozoan Entamoeba histolytica, which is a rare infectious disease in developed countries. If the trophozoites enter the blood, it can...
BACKGROUND
Amoebiasis is caused by the protozoan Entamoeba histolytica, which is a rare infectious disease in developed countries. If the trophozoites enter the blood, it can spread through the body, such as brain, and lungs. Cases of simultaneous infection of multiple organs are extremely rare.
CASE PRESENTATION
Here we report a case of simultaneous infection of amoeba in pulmonary pleura, urinary system and central nervous system. Although the patient received anti amoeba treatment, the prognosis of the patient was poor.
CONCLUSIONS
In this patient, multiple extraintestinal amebic infections in the absence of clinically confirmed intestinal amebiasis or amebic liver abscess are rare and pose diagnostic challenges. The disseminated amebiasis has significantly increased the mortality. Early diagnosis and appropriate treatment may reduce the mortality of disseminated amebiasis.
Topics: Amebiasis; Dysentery, Amebic; Entamoeba histolytica; Entamoebiasis; Humans; Liver Abscess, Amebic
PubMed: 35410146
DOI: 10.1186/s12879-022-07348-9 -
Frontiers in Cellular and Infection... 2020Amebiasis is a neglected tropical disease which is caused by the protozoan parasite . This disease is one of the leading causes of diarrhea globally, affecting largely... (Review)
Review
Amebiasis is a neglected tropical disease which is caused by the protozoan parasite . This disease is one of the leading causes of diarrhea globally, affecting largely impoverished residents in developing countries. Amebiasis also remains one of the top causes of gastrointestinal diseases in returning international travellers. Despite having many side effects, metronidazole remains the drug of choice as an amebicidal tissue-active agent. However, emergence of metronidazole resistance in pathogens having similar anaerobic metabolism and also in laboratory strains of has necessitated the identification and development of new drug targets and therapeutic strategies against the parasite. Recent research in the field of amebiasis has led to a better understanding of the parasite's metabolic and cellular pathways and hence has been useful in identifying new drug targets. On the other hand, new molecules effective against amebiasis have been mined by modifying available compounds, thereby increasing their potency and efficacy and also by repurposing existing approved drugs. This review aims at compiling and examining up to date information on promising drug targets and drug molecules for the treatment of amebiasis.
Topics: Amebiasis; Drug Development; Dysentery, Amebic; Entamoeba histolytica; Humans; Metronidazole
PubMed: 33718258
DOI: 10.3389/fcimb.2020.628257 -
California Medicine Dec 1956Pleuropulmonary amebiasis may be manifest without diarrhea or dysentery.In obscure lesions of the right lower lung field, one should always consider pleuropulmonary...
Pleuropulmonary amebiasis may be manifest without diarrhea or dysentery.In obscure lesions of the right lower lung field, one should always consider pleuropulmonary amebiasis-especially with low grade fever and moderate leukocytosis. Abscess and empyema contents should be examined promptly microscopically or kept warm to preserve the motility of the trophozoites until satisfactory examination is possible. Conservative therapy will successfully manage most cases of pleuropulmonary amebiasis. If a thorough search fails to reveal Entameba histolytica, and the diagnosis is still entertained, a medical therapeutic trial is in order.
Topics: Abscess; Amebiasis; Animals; Dysentery; Dysentery, Amebic; Empyema; Entamoeba histolytica; Humans; Lung Diseases; Lung Diseases, Parasitic; Trophozoites
PubMed: 13374556
DOI: No ID Found