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Veterinary Parasitology Jul 1989Selected parasitic zoonoses are discussed with emphasis on epidemiological, diagnostic and some chemotherapeutic aspects. Pneumocystosis, toxoplasmosis,... (Review)
Review
Selected parasitic zoonoses are discussed with emphasis on epidemiological, diagnostic and some chemotherapeutic aspects. Pneumocystosis, toxoplasmosis, cryptosporidiosis and microsporidiosis are briefly reviewed as "AIDS-related zoonoses". Up to now 5 genera of Microsporidia have been identified as causative agents of human infections, including Encephalitozoon cuniculi, Enterocytozoon bieneusi and Pleistophora sp. which were found in AIDS patients. From the many "other parasitic zoonoses", giardiasis, echinococcosis and taeniosis/cysticercosis are discussed as examples. Significant advances in the understanding of transmission dynamics, in strain characterisation and diagnosis of the diseases have been achieved.
Topics: Acquired Immunodeficiency Syndrome; Animals; Cryptosporidiosis; Echinococcosis; Giardiasis; Humans; Parasitic Diseases; Pneumonia, Pneumocystis; Protozoan Infections; Taeniasis; Toxoplasmosis; Zoonoses
PubMed: 2669318
DOI: 10.1016/0304-4017(89)90154-4 -
Ecotoxicology and Environmental Safety Jul 2006Roach (Rutilus rutilus) from Danish streams that receive discharges of domestic sewage effluent were examined for the presence of alterations to gonadal development. In...
Roach (Rutilus rutilus) from Danish streams that receive discharges of domestic sewage effluent were examined for the presence of alterations to gonadal development. In male roach, intersex was observed at a prevalence of 4.5-5% at reference sites and 6.7-6.5% at sewage effluent-impacted sites. A positive correlation was found between sewage effluent load and intersex frequency among male roach. The highest frequency of intersex (26.5%) was found in the stream Kristrup Landkanal, which had the highest percentage and load of sewage effluent (87,578 population equivalents). Further, a tendency to an average higher severity of the phenomenon (calculated as an intersex index value) was seen in males from streams impacted by sewage effluent compared to males from reference sites. However, this was significant only in male fish from Egaa Brook. Among roach from the Kristrup Landkanal 5.8% of male and 0.8% of female roach were infected with the parasite Pleistophora mirandellae, causing degenerative changes in testes and ovaries. No correlation was seen between the intersex condition and the presence of P. mirandellae in the gonads of roach.
Topics: Animals; Cyprinidae; Denmark; Disorders of Sex Development; Environmental Monitoring; Epidemiological Monitoring; Female; Host-Parasite Interactions; Male; Ovary; Parasitic Diseases, Animal; Pleistophora; Sewage; Testis; Water Pollutants, Chemical
PubMed: 16054215
DOI: 10.1016/j.ecoenv.2005.05.018 -
Folia Parasitologica 1991In the years 1985-1988, a total of 254 specimens of the roach, Rutilus rutilus, captured in 23 localities of South Bohemia, were examined for the presence of protozoan...
In the years 1985-1988, a total of 254 specimens of the roach, Rutilus rutilus, captured in 23 localities of South Bohemia, were examined for the presence of protozoan parasites. Only 17 specimens (6.7%) were free of infection, whereas the others were infected at least with one parasite species, mixed infections were observed most frequently. The following species were found rarely: Myxidium rhodei Léger, 1905 in the liver and muscles. Pleistophora mirandellae Vaney et Conte, 1901 in ovaries, Trichodina nemachili Lom, 1960 on the skin, Trichodina prowazeki Grupcheva et Lom, 1980 on the skin (the first finding in Czechoslovakia). The data concerning localization of individual parasites and their prevalence are presented and five protozoan species described in detail.
Topics: Animals; Brain; Cyprinidae; Czechoslovakia; Eukaryota; Female; Fish Diseases; Gallbladder; Gills; Intestines; Liver; Ovary; Protozoan Infections; Protozoan Infections, Animal; Skin; Spleen; Urinary Tract
PubMed: 1916526
DOI: No ID Found -
Revista Medica de Chile Jun 1995The importance of microsporidium as an opportunistic agent in immunocompromised and AIDS patients is reviewed. Five strains of the agent have been described:... (Review)
Review
The importance of microsporidium as an opportunistic agent in immunocompromised and AIDS patients is reviewed. Five strains of the agent have been described: Encephalitozoon, Enterocytozoon, Nosema, Pleistophora and Septata. The clinical presentation may be as 1) Generalized infections with multisystemic involvement, specially of the central nervous system; 2) Intestinal, that is the most important and frequent localization in man, and that may cause death in AIDS patients; 3) Ocular, that affects cornea, conjunctiva and may extend to paranasal sinuses; 4) Liver and biliary tract infection with granulomatous lesions, hepatic necrosis or sclerosing colangitis and 5) Muscular, affecting skeletal muscle. The diagnosis is difficult and is established finding spores in the affected tissues with light or electron microscopy. Lately, the diagnosis of intestinal microsporidiosis is made looking for faecal spores. The resistant wall of spores hampers treatment. However, good results are obtained with Albendazole in intestinal microsporidiosis.
Topics: AIDS-Related Opportunistic Infections; Animals; Child; Child, Preschool; Female; Humans; Infant; Intestinal Diseases, Parasitic; Male; Microsporida; Microsporidiosis
PubMed: 8525232
DOI: No ID Found -
Proceedings. Biological Sciences Jun 2003Parasites can structure biological communities directly through population regulation and indirectly by processes such as apparent competition. However, the role of...
Parasites can structure biological communities directly through population regulation and indirectly by processes such as apparent competition. However, the role of parasites in the process of biological invasion is less well understood and mechanisms of parasite mediation of predation among hosts are unclear. Mutual predation between native and invading species is an important factor in determining the outcome of invasions in freshwater amphipod communities. Here, we show that parasites mediate mutual intraguild predation among native and invading species and may thereby facilitate the invasion process. We find that the native amphipod Gammarus duebeni celticus is host to a microsporidian parasite, Pleistophora sp. (new species), with a frequency of infection of 0-90%. However, the parasite does not infect three invading species, G. tigrinus, G. pulex and Crangonyx pseudogracilis. In field and laboratory manipulations, we show that the parasite exhibits cryptic virulence: the parasite does not affect host fitness in single-species populations, but virulence becomes apparent when the native and invading species interact. That is, infection has no direct effect on G. d. celticus survivorship, size or fecundity; however, in mixed-species experiments, parasitized natives show a reduced capacity to prey on the smaller invading species and are more likely to be preyed upon by the largest invading species. Thus, by altering dominance relationships and hierarchies of mutual predation, parasitism strongly influences, and has the potential to change, the outcome of biological invasions.
Topics: Amphipoda; Animals; Female; Host-Parasite Interactions; Ireland; Male; Parasites; Population Dynamics; Predatory Behavior; Virulence
PubMed: 12816645
DOI: 10.1098/rspb.2003.2358 -
Diseases of Aquatic Organisms Oct 2019In Northern Ireland, the amphipods Gammarus duebeni celticus (native) and G. pulex (invasive) coexist in some places, whilst in others the native species has been...
In Northern Ireland, the amphipods Gammarus duebeni celticus (native) and G. pulex (invasive) coexist in some places, whilst in others the native species has been replaced by the invader. We explored the role of parasites in mediating interactions between these amphipods, which demonstrate mutual intraguild predation (IGP: predation between animals that also compete for prey). IGP and cannibalism can be important factors in structuring populations and communities. We investigated the effects of parasitism on rates of IGP between G. d. celticus and G. pulex and on cannibalism within each species by comparing functional responses (FRs: relationships between the use of a prey resource and its availability). Infection with the microsporidian Pleistophora mulleri caused an increase in IGP and cannibalism by G. d. celticus, which showed increased attack rates and reduced prey handling times. In contrast, infection with the acanthocephalan parasite Echinorhynchus truttae did not alter IGP or cannibalism by G. pulex. A prey preference experiment revealed that both amphipods were more likely to feed on heterospecific rather than conspecific prey, and this was also corroborated by the fact that overall IGP FRs were higher than cannibalism FRs. This may be selectively advantageous, as feeding on heterospecific prey removes possible competitors without the risk of consuming juvenile kin or acquiring parasites from infected conspecifics. Infection of the native G. d. celticus with P. mulleri enhanced IGP on the invasive G. pulex, which is likely to facilitate the coexistence of the 2 species.
Topics: Amphipoda; Animals; Cannibalism; Host-Parasite Interactions; Introduced Species; Pleistophora; Predatory Behavior
PubMed: 31575836
DOI: 10.3354/dao03415 -
Clinical Microbiology and Infection :... Feb 1995Human microsporidiosis is a parasitic infection due to species of four different genera: Encephalitozoon; Enterocytozoon; Nosema; and Pleistophora. Although well known...
Human microsporidiosis is a parasitic infection due to species of four different genera: Encephalitozoon; Enterocytozoon; Nosema; and Pleistophora. Although well known as a cause of disease in animals, microsporidiosis was only occasionally reported in humans. Recently, in human immunodeficiency virus (HIV)-infected patients, microsporidia belonging to Encephalitozoon and Enterocytozoon species have proved to be important opportunistic pathogens. Enterocytozoon bieneusi is associated with chronic intermittent diarrhea, cholangiopathy and sinusitis whereas Encephalitozoon intestinalis, Encephalitozoon hellem and Encephalitozoon cuniculi, the three Encephalitozoon species found in humans, are associated with diarrhea, rhinosinusitis, keratoconjunctivitis, nephritis and hepatitis. Diagnosis of microsporidial infections in humans was until recently an invasive, laborious procedure including electron microscopy of small intestine biopsies. However, new simple staining methods using Uvitex 2B or modified trichrome stain for feces and other body fluids have facilitated clinical diagnosis as well as drug evaluation and epidemiological studies. The application of monoclonal antibodies and molecular techniques such as the polymerase chain reaction have further improved microsporidial diagnosis. Treatment of Entero. bieneusi has, until now, been unsuccessful whereas albendazole has proved to be an effective treatment for Encephalitozoon species infection. Identification of effective treatment for Entero. bieneusi infections and further study of the pathogenicity of these microsporidial infections in immunocompetent hosts are important future challenges.
PubMed: 11866734
DOI: 10.1111/j.1469-0691.1995.tb00450.x -
Mikrobiyoloji Bulteni Oct 2005Microsporidia are single celled, obligate intracellular, spore forming microorganisms which were first described as a cause of human disease in 1959. They are capable of... (Review)
Review
Microsporidia are single celled, obligate intracellular, spore forming microorganisms which were first described as a cause of human disease in 1959. They are capable of infecting a wide variety of vertebrate and invertebrate hosts. Among the numerous microsporidial genera, seven have been described in human diseases such as Enterocytozoon, Encephalitozoon, Nosema, Pleistophora, Trachipleistophora, Vittaforma, Brachiola. Among these, Enterocytozoon bieneusi is the most frequently identified microsporidian in the patients. Features used in identification include spore size, nuclear configuration of spores, the number of polar tubule coils and the parazite-host interaction. In the development of Microsporidia, there are two different phases, called as proliferative phase and sporogonic phase. The only stage of Microsporidia outside the host is infective spores. The microsporidial spore is highly specialized, environmentally resistant structure that varies in size and shape according to species. They can cause infections both in immunocompetent subjects and immunocompromised patients such as AIDS. Although it can cause self-limiting infections in immunocompetent patients, it can cause severe life threating infections especially AIDS patients. In this review, the basic biology, epidemiologic characteristics and immunopathogenesis of Microsporidia, together with the diagnosis and treatment of the infections have been discussed.
Topics: Acquired Immunodeficiency Syndrome; Animals; Humans; Immunocompetence; Immunocompromised Host; Microsporidia; Microsporidiosis; Spores, Fungal
PubMed: 16544554
DOI: No ID Found -
International Journal For Parasitology Jul 2003In its freshwater amphipod host Gammarus duebeni celticus, the microsporidian parasite Pleistophora mulleri showed 23% transmission efficiency when uninfected...
In its freshwater amphipod host Gammarus duebeni celticus, the microsporidian parasite Pleistophora mulleri showed 23% transmission efficiency when uninfected individuals were fed infected tissue, but 0% transmission by water-borne and coprophagous routes. Cannibalism between unparasitised and parasitised individuals was significantly in favour of the former (37% compared to 0%). In addition, cannibalism between parasitised individuals was significantly higher than between unparasitised individuals (27% compared to 0%). Thus, parasitised individuals were more likely to be cannibalised by both unparasitised and parasitised individuals. We discuss the conflicting selective forces within this host/parasite relationship, the implications of parasite mediated cannibalism for host population structure and the impacts this may have on the wider aquatic community.
Topics: Animals; Behavior, Animal; Cannibalism; Crustacea; Fresh Water; Host-Parasite Interactions; Microsporidiosis; Pleistophora
PubMed: 12865079
DOI: 10.1016/s0020-7519(03)00110-3 -
Journal of Clinical Microbiology Nov 1994Microsporidia are primitive, spore-forming, mitochondria-lacking, eukaryotic protozoa that are obligate intracellular parasites. They are known to parasitize almost...
Polyclonal and monoclonal antibody and PCR-amplified small-subunit rRNA identification of a microsporidian, Encephalitozoon hellem, isolated from an AIDS patient with disseminated infection.
Microsporidia are primitive, spore-forming, mitochondria-lacking, eukaryotic protozoa that are obligate intracellular parasites. They are known to parasitize almost every group of animals including humans. Recently, microsporidia have increasingly been found to infect patients with AIDS. Five genera (Encephalitozoon, Enterocytozoon, Nosema, Septata, and Pleistophora) of microsporidia are known to infect humans. Enterocytozoon organisms cause gastrointestinal disease in a majority of AIDS patients with microsporidiosis. However, a smaller, but an expanding, number of patients with AIDS are being diagnosed with ocular and disseminated infection with Encephalitozoon hellem. Although microsporidial spores can be identified in clinical samples by a staining technique such as one with Weber's chromotrope stain, identification to the species level is dependent on cumbersome and time-consuming electron microscopy. We have recently isolated and established in continuous culture several strains of E. hellem from urine, bronchoalveolar lavage, and sputum samples from AIDS patients with disseminated microsporidiosis. We developed polyclonal and monoclonal antibodies and PCR primers to a strain of E. hellem that can be used successfully to identify E. hellem from other species of microsporidia either in clinical specimens or in cultures established from clinical specimens. Since patients infected with Encephalitozoon spp. are known to respond favorably to albendazole, identification of the parasite to the species level would be invaluable in the treatment of disseminated microsporidiosis.
Topics: Acquired Immunodeficiency Syndrome; Animals; Antibodies, Monoclonal; Antigens, Protozoan; Base Sequence; DNA, Protozoan; Encephalitozoon; Female; Humans; Immunoblotting; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Ribosomal; Rabbits
PubMed: 7852569
DOI: 10.1128/jcm.32.11.2760-2768.1994