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Expert Opinion on Therapeutic Targets Nov 2018Microsporidia have been increasingly reported to infect humans. The most common presentation of microsporidiosis is chronic diarrhea, a significant mortality risk in... (Review)
Review
Microsporidia have been increasingly reported to infect humans. The most common presentation of microsporidiosis is chronic diarrhea, a significant mortality risk in immune-compromised patients. Albendazole, which inhibits tubulin, and fumagillin, which inhibits methionine aminopeptidase type 2 (MetAP2), are the two main therapeutic agents used for treatment of microsporidiosis. In addition, to their role as emerging pathogens in humans, microsporidia are important pathogens in insects, aquaculture, and veterinary medicine. New therapeutic targets and therapies have become a recent focus of attention for medicine, veterinary, and agricultural use. Areas covered: Herein, we discuss the detection and symptoms of microsporidiosis in humans and the therapeutic targets that have been utilized for the design of new drugs for the treatment of this infection, including triosephosphate isomerase, tubulin, MetAP2, topoisomerase IV, chitin synthases, and polyamines. Expert opinion: Enterocytozoon bieneusi is the most common microsporidia in human infection. Fumagillin has a broader anti-microsporidian activity than albendazole and is active against both Ent. bieneusi and Encephaliozoonidae. Microsporidia lack methionine aminopeptidase type 1 and are, therefore, dependent on MetAP2, while mammalian cells have both enzymes. Thus, MetAP2 is an essential enzyme in microsporidia and new inhibitors of this pathway have significant promise as therapeutic agents.
Topics: Albendazole; Animals; Antifungal Agents; Cyclohexanes; Drug Design; Fatty Acids, Unsaturated; Humans; Microsporidia; Microsporidiosis; Molecular Targeted Therapy; Sesquiterpenes
PubMed: 30336698
DOI: 10.1080/14728222.2018.1538360 -
Gastroenterologie Clinique Et Biologique Sep 2010Microsporidiosis is an emerging and opportunistic infection in AIDS patients, organ transplant recipients, children, travelers, contact lens wearers and the elderly. It... (Review)
Review
Microsporidiosis is an emerging and opportunistic infection in AIDS patients, organ transplant recipients, children, travelers, contact lens wearers and the elderly. It is associated with a wide range of clinical syndromes of microsporidiosis in humans. The disease is caused by microsporidia, obligate intracellular microorganisms that were recently reclassified from protozoa to fungi. The 14 species of microsporidia currently known to infect humans, Enterocytozoon bieneusi and Encephalitozoon intestinalis, are the most common causes of human infections and are associated with diarrhea and systemic disease. Species of microsporidia infecting humans have been identified in water sources as well as in wild, domestic and food-producing farm animals, raising concerns of water-borne, food-borne and zoonotic transmission. Various molecules have been tested for treating microsporidiosis in humans with variable success. Albendazole is effective against Encephalitozoon species such us Encephalitozoon intestinalis but not against Enterocytozoon bieneusi. This species has shown excellent clinical therapeutic response to direct action with fumagillin, but this drug is toxic when administered systematically to mammals. Its analog, TNP 470, could be promising alternative. Further work is necessary to identify other drugs, which are both effective and devoid of adverse effects.
Topics: Antifungal Agents; Biliary Tract Diseases; Communicable Diseases, Emerging; Gastrointestinal Diseases; Humans; Immunocompromised Host; Liver Diseases; Microsporidia; Microsporidiosis; Opportunistic Infections; Pancreatic Diseases; Prevalence; Risk Factors
PubMed: 20702053
DOI: 10.1016/j.gcb.2010.07.003 -
Developmental and Comparative Immunology Nov 2016Fish intestinal parasites cause direct mortalities and also morbidity, poor growth, higher susceptibility to opportunistic pathogens and lower resistance to stress. This... (Review)
Review
Fish intestinal parasites cause direct mortalities and also morbidity, poor growth, higher susceptibility to opportunistic pathogens and lower resistance to stress. This review is focused on microscopic parasites (Protozoa and Metazoa) that invade the gastrointestinal tract of fish. Intracellular parasites (mainly Microsporidia and Apicomplexa) evoke almost no host immune reaction while they are concealed in the cytoplasmic and nuclear compartments, and can even use fish cells (macrophages) as Trojan horses to spread in the host. Inflammatory reaction only appears when the parasite bursts infected cells. Immunity against extracellular parasites is depicted for the myxozoans Ceratonova shasta and Enteromyxum spp. The cellular and humoral innate responses and the production of antibodies are crucial for resolving some of these myxozoonoses, but an excessive inflammatory reaction (concerted by cytokines) can become a fatal pathophysiological consequence. The local immune response plays a key role, with numerous genes more strongly regulated in the intestine than at lymphohaematopoietic organs.
Topics: Animals; Apicomplexa; Fishes; Gastrointestinal Tract; Immune Evasion; Immunity, Innate; Inflammation; Microsporidia; Microsporidiosis; Myxozoa; Parasitic Diseases, Animal; Protozoan Infections
PubMed: 26828391
DOI: 10.1016/j.dci.2016.01.014 -
Clinical Microbiology Reviews Jan 1997Protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. The waterborne parasites Giardia lamblia,... (Review)
Review
Protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. The waterborne parasites Giardia lamblia, Naegleria fowleri, Acanthamoeba spp., Entamoeba histolytica, Cryptosporidium parvum, Cyclospora cayetanesis, Isospora belli, and the microsporidia are reviewed. For each parasite, the review includes history, life cycle, incidence, symptoms, and therapy. Clinical detection methods are compared, and emerging technologies are discussed. Information on the association of these parasites with waterborne outbreaks is reviewed. Current information on protozoan parasites identified as etiological agents in waterborne outbreaks is discussed. Water industry issues related to recent disease outbreaks are examined in the context of water quality testing regulations for G. lamblia and those proposed for C. parvum. The review identifies the limitations of the American Society of Testing and Materials water-testing method for these parasites. An overview of federal regulations affecting the water industry and laboratories that test for water quality is also provided. The article highlights the importance of the clinical laboratory as a frontline defense for the detection of infectious organisms. The review points to the need for clinical laboratories, physicians, and public health personnel to cooperatively plan and assess the challenge of meeting this potential public health threat.
Topics: Acanthamoeba; Amebiasis; Amebicides; Animals; Anti-Infective Agents; Antifungal Agents; Antiprotozoal Agents; Antitrichomonal Agents; Coccidiosis; Cryptosporidiosis; Cryptosporidium parvum; Eimeriida; Entamoeba histolytica; Entamoebiasis; Giardia lamblia; Giardiasis; Humans; Isospora; Microsporida; Microsporidiosis; Naegleria fowleri; Protozoan Infections; Water Microbiology; Water Supply
PubMed: 8993859
DOI: 10.1128/CMR.10.1.67 -
Frontiers in Cellular and Infection... 2022Emerging infectious disease has become the center of attention since the outbreak of COVID-19. For the coronavirus, bats are suspected to be the origin of the pandemic.... (Review)
Review
Emerging infectious disease has become the center of attention since the outbreak of COVID-19. For the coronavirus, bats are suspected to be the origin of the pandemic. Consequently, the spotlight has fallen on zoonotic diseases, and the focus now expands to organisms other than viruses. Microsporidia is a single-cell organism that can infect a wide range of hosts such as insects, mammals, and humans. Its pathogenicity differs among species, and host immunological status plays an important role in infectivity and disease severity. Disseminated disease from microsporidiosis can be fatal, especially among patients with a defective immune system. Recently, there were two , a microsporidia species which can survive in insects, case reports in Thailand, one patient had disseminated microsporidiosis. This review gathered data of disseminated microsporidiosis and infections in humans covering the biological and clinical aspects. There was a total of 22 cases of disseminated microsporidiosis reports worldwide. Ten microsporidia species were identified. Maximum likelihood tree results showed some possible correlations with zoonotic transmissions. For hominis, there are currently eight case reports in humans, seven of which had Human Immunodeficiency Virus (HIV) infection. It is observed that risks are higher for the immunocompromised to acquire such infections, however, future studies should look into the entire life cycle, to identify the route of transmission and establish preventive measures, especially among the high-risk groups.
Topics: Animals; COVID-19; Humans; Immunocompromised Host; Mammals; Microsporidia; Microsporidiosis; Zoonoses
PubMed: 35782144
DOI: 10.3389/fcimb.2022.924007 -
Microbes and Infection Apr 2001Microsporidia are considered opportunistic pathogens in humans because they are most likely to cause diseases if the immune status of a host is such that the infection... (Review)
Review
Microsporidia are considered opportunistic pathogens in humans because they are most likely to cause diseases if the immune status of a host is such that the infection cannot be controlled. A wide spectrum of diseases has been reported among persons infected with microsporidia and different diagnostic techniques have been developed during the last decade.
Topics: AIDS-Related Opportunistic Infections; Animals; Humans; Microsporida; Microsporidiosis; Opportunistic Infections
PubMed: 11369276
DOI: 10.1016/s1286-4579(01)01395-8 -
Microbes and Infection May 2000Microsporidia are small, single-celled, obligately intracellular parasites that have caused significant agricultural losses and interference with biomedical research.... (Review)
Review
Microsporidia are small, single-celled, obligately intracellular parasites that have caused significant agricultural losses and interference with biomedical research. Interest in the microsporidia is growing, as these organisms are recognized as agents of opportunistic infections in persons with AIDS and in organ transplant recipients. Microsporidiosis is also being recognized in children and travelers, and furthermore, concern exists about the potential of zoonotic and waterborne transmission of microsporidia to humans. This article reviews the basic biology and epidemiology of microsporidiosis in mammals.
Topics: AIDS-Related Opportunistic Infections; Animals; Humans; Mice; Microsporida; Microsporidiosis
PubMed: 10884622
DOI: 10.1016/s1286-4579(00)00354-3 -
Emerging Infectious Diseases Mar 2022We identified Encephalitozoon cuniculi genotype II parasites as a cause of extraintestinal microsporidiosis in 2 owners of birds also infected with E. cuniculi. Patients...
We identified Encephalitozoon cuniculi genotype II parasites as a cause of extraintestinal microsporidiosis in 2 owners of birds also infected with E. cuniculi. Patients experienced long-lasting nonspecific symptoms; the disease course was more progressive in a patient with diabetes. Our findings suggest direct bird-to-human transmission of this pathogen.
Topics: Animals; Birds; Encephalitozoon cuniculi; Encephalitozoonosis; Genotype; Humans; Microsporidiosis
PubMed: 35202528
DOI: 10.3201/eid2803.211556 -
ILAR Journal 2012Pseudoloma neurophilia (Microsporidia) is the most common pathogen detected in zebrafish (Danio rerio) from research facilities. The parasite infects the central nervous... (Review)
Review
Pseudoloma neurophilia (Microsporidia) is the most common pathogen detected in zebrafish (Danio rerio) from research facilities. The parasite infects the central nervous system and muscle and may be associated with emaciation and skeletal deformities. However, many fish exhibit subclinical infections. Another microsporidium, Pleistophora hyphessobryconis, has recently been detected in a few zebrafish facilities. Here, we review the methods for diagnosis and detection, modes of transmission, and approaches used to control microsporidia in zebrafish, focusing on P. neurophilia. The parasite can be readily transmitted by feeding spores or infected tissues, and we show that cohabitation with infected fish is also an effective means of transmission. Spores are released from live fish in various manners, including through the urine, feces, and sex products during spawning. Indeed, P. neurophilia infects both the eggs and ovarian tissues, where we found concentrations ranging from 12,000 to 88,000 spores per ovary. Hence, various lines of evidence support the conclusion that maternal transmission is a route of infection: spores are numerous in ovaries and developing follicles in infected females, spores are present in spawned eggs and water from spawning tanks based on polymerase chain reaction tests, and larvae are very susceptible to the infection. Furthermore, egg surface disinfectants presently used in zebrafish laboratories are ineffective against microsporidian spores. At this time, the most effective method for prevention of these parasites is avoidance.
Topics: Animals; Fish Diseases; Microsporidiosis; Pleistophora; Zebrafish
PubMed: 23382342
DOI: 10.1093/ilar.53.2.106 -
Medical Mycology Sep 2022Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi...
Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and other mammals and birds. Data on the epidemiology of E. bieneusi in wildlife are limited. Hence, E. bieneusi was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from five Spanish bioregions. The parasite was detected only in red deer (10.4%, 68/653) and wild boar (0.8%, 3/359). Enterocytozoon bieneusi infections were more common in farmed (19.4%, 63/324) than in wild (1.5%, 5/329) red deer. A total of 11 genotypes were identified in red deer, eight known (BEB6, BEB17, EbCar2, HLJD-V, MWC_d1, S5, Type IV, and Wildboar3) and three novel (DeerSpEb1, DeerSpEb2, and DeerSpEb3) genotypes. Mixed genotype infections were detected in 15.9% of farmed red deer. Two genotypes were identified in wild boar, a known (Wildboar3) and a novel (WildboarSpEb1) genotypes. All genotypes identified belonged to E. bieneusi zoonotic Groups 1 and 2. This study provides the most comprehensive epidemiological study of E. bieneusi in Spanish ungulates to date, representing the first evidence of the parasite in wild red deer populations worldwide. Spanish wild boars and red deer are reservoir of zoonotic genotypes of E. bieneusi and might play an underestimated role in the transmission of this microsporidian species to humans and other animals.
Topics: Animals; Animals, Wild; China; Deer; Enterocytozoon; Feces; Genotype; Humans; Microsporidiosis; Phylogeny; Prevalence; Sheep; Sheep Diseases; Spain; Sus scrofa; Swine; Swine Diseases
PubMed: 36095135
DOI: 10.1093/mmy/myac070