Protistan parasites have an undisputed global health impact. However, outside of a few key exceptions, e.g. the agent of malaria, most of these infectious agents are neglected as important health threats. The Symposium entitled "Free-living amoebae and neglected pathogenic protozoa: health emergency signals?" held at the European Congress of Protistology in Rome, July 2019, brought together researchers addressing scientific and clinical questions about some of these fascinating organisms. Topics presented included the molecular basis of pathogenicity in Acanthamoeba; genomics of Naegleria fowleri; and epidemiology of poorly diagnosed enteric protistan species, including Giardia, Cryptosporidium, Blastocystis, Dientamoeba. The Symposium aim was to excite the audience about the opportunities and challenges of research in these underexplored organisms and to underline the public health implications of currently under-appreciated protistan infections. The major take home message is that any knowledge that we gain about these organisms will allow us to better address them, in terms of monitoring and treatment, as sources of future health emergencies.
- Klíčová slova
- Enteric protozoa, Free-living amoebae, Neglected protozoa, Pathogenic protozoa,
- MeSH
- Amoeba patogenita MeSH
- celosvětové zdraví * MeSH
- Eukaryota patogenita MeSH
- lidé MeSH
- protozoální infekce parazitologie MeSH
- virulence genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
Species of amoebae belonging to the genera Platyamoeba Page, 1969, Vannella Bovee, 1965 and Flabellula Schaeffer, 1926 were found to accompany Paramoeba sp., the agent of amoebic gill disease (AGD), in clinically diseased turbots. The same community of epizoic gymnamoebae was found on the gills of turbots which revealed no gill abnormalities but slight behavioral signs indicative of suboptimal health status. The assemblage of the above-mentioned free-living amoebae capable of colonizing gill tissue of turbots was supplemented with species recognized in samples fixed from primary isolates for transmission electron microscopy. The pathogenic potential of epizoic gill amoebae in turbots is discussed.
- MeSH
- amébiáza parazitologie veterinární MeSH
- Amoeba klasifikace patogenita ultrastruktura MeSH
- elektronová mikroskopie veterinární MeSH
- nemoci ryb parazitologie MeSH
- platýsi parazitologie MeSH
- žábry parazitologie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. Despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such 'evergreens' as the ciliate Ichthyophthirius multifiliis, a causative agent of white spot disease, or proliferative kidney disease (PKD), one of the most economically damaging diseases in the rainbow trout industry which causative agent remain enigmatic. Besides long-recognized parasites, other potentially severe pathogens have appeared quite recently such as amphizoic amoebae, causative agents of amoebic gill disease (AGD), the monogenean Gyrodactylus salaris which has destroyed salmon populations in Norway, or sea lice, in particular Lepeophtheirus salmonis that endanger marine salmonids in some areas. Recent spreading of some parasites throughout the world (e.g. the cestode Bothriocephalus acheilognathi) has been facilitated through insufficient veterinary control during import of fish. Control of many important parasitic diseases is still far from being satisfactory and further research is needed. Use of chemotherapy has limitations and new effective, but environmentally safe drugs should be developed. A very promising area of future research seems to be studies on immunity in parasitic infections, use of molecular technology in diagnostics and development of new vaccines against the most pathogenic parasites.
- MeSH
- amébiáza prevence a kontrola veterinární MeSH
- Amoeba patogenita MeSH
- cizopasní červi patogenita MeSH
- Eukaryota patogenita MeSH
- helmintózy zvířat prevence a kontrola MeSH
- Hymenostomatida patogenita MeSH
- korýši patogenita MeSH
- losos MeSH
- nemoci ledvin parazitologie prevence a kontrola veterinární MeSH
- nemoci ryb parazitologie prevence a kontrola MeSH
- Oncorhynchus mykiss MeSH
- parazitární nemoci u zvířat parazitologie prevence a kontrola MeSH
- protozoální infekce zvířat prevence a kontrola MeSH
- ryby MeSH
- vodní hospodářství * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- MeSH
- amébiáza parazitologie MeSH
- Amoeba klasifikace izolace a purifikace patogenita MeSH
- lidé MeSH
- meningoencefalitida parazitologie MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Six strains of nonvirulent and three strains of virulent variants of Naegleria fowleri amoebae were isolated from the examined cooling water samples from 9 power plants. The virulent variants were obtained solely from effluents discharged from power plants with a closed-circuit cooling N. fowleri was not detected outside the reach of the thermal pollution. A disinfection of out-flowing cooling water seems to be an unnecessary investment in our climate. Warm discharge water should under no conditions be used directly for sports and recreational purposes.
- MeSH
- Amoeba izolace a purifikace patogenita MeSH
- elektrárny * MeSH
- myši MeSH
- teplota MeSH
- voda * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Československo MeSH
- Názvy látek
- voda * MeSH
Two complexes of lakes and canals supplying water for two electric power plants, their steam condensors and an adjoining river were investigated by means of culture methods for the presence of Naegleria fowleri in Poland in the period from 1974 to 1980. Sixty-four strains of N. fowleri were isolated, 13 isolates being virulent for mice when instilled intranasally. These strains were found in the steam condensor of the power station A and in waters polluted with warm water of this plant. Pathogenic N. fowleri strains occurred also in an adjoining river connected with the water system of the power plant. The results show the possible role of the steam condensor A as an incubator and regular source of pollution with pathogenic amoebae for its own system of cooling waters and even the adjoining river.
- MeSH
- Amoeba izolace a purifikace patogenita MeSH
- mikrobiologie vody * MeSH
- roční období MeSH
- teplota MeSH
- znečištění vody * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- Amoeba cytologie patogenita fyziologie MeSH
- antigeny MeSH
- kultivační média MeSH
- myši MeSH
- plavecké bazény * MeSH
- voda * MeSH
- zkřížené reakce MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antigeny MeSH
- kultivační média MeSH
- voda * MeSH
Naegleria fowleri was isolated from water during a hygienic inspection of a swimming pool in December 1977. This swimming pool was identified as a source of the infectious agent in the years 1962-1965, when a large outbreak of primary amoebic meningoencephalitis (PAME) occurred. First two strains of N. fowleri, pathogenic for white mice after intracerebral and intranasal inoculation, were isolated from water of outlet troughs, additional strains were then isolated from various places; particularly from a cavity in the damaged wall of the pool. The incubation temperature did not inhibit a simultaneous growth of amoebae of the genera Acanthamoeba, Flabellula, Hartmannella and Vahlkampfia in the primocultures. Epidemiological investigations did not reveal any new case of PAME in relation with the occurrence of pathogenic N. fowleri in the swimming pool.
- MeSH
- amébiáza parazitologie MeSH
- Amoeba růst a vývoj izolace a purifikace patogenita MeSH
- dezinfekce MeSH
- lidé MeSH
- meningoencefalitida parazitologie MeSH
- myši MeSH
- plavecké bazény * MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Československo MeSH
Laboratory examination methods and processes recommended for the diagnosis of primary amoebic meningo-encephalitis and detection of Naegleria fowleri in the environment are summarized. The most simple methods suitable for diagnostic laboratories in the sphere of medical parasitology have been chosen.
- MeSH
- amébiáza diagnóza parazitologie MeSH
- Amoeba růst a vývoj izolace a purifikace patogenita MeSH
- lidé MeSH
- meningoencefalitida diagnóza parazitologie MeSH
- mozek parazitologie MeSH
- mozkomíšní mok parazitologie MeSH
- myši MeSH
- parazitologie metody MeSH
- půda MeSH
- voda MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- půda MeSH
- voda MeSH
In brain sections of the Naegleria-caused cases of primary amoebic meningoencephalitis, extensive demyelinization was found in the white matter, besides the severe histopathological changes and large clusters of trophozoites in the grey matter. The myelinoclasis appeared to be a result of a specific phospholipolytic effect, unlike that in post-viral encephalomyelitis, which has been attributed to vascular blockade or hemorrhages. In monkey kidney cell cultures a very early cytopathic effect was observed and traced to the cytolytic property of the seeding culture fluid. Rat brain slices inoculated with Naegleria culture exhibited amoebic growth and demyelinization in 28-52 hours incubation at 35 degrees C. In a chemically defined medium containing sphingomyelin, casein and glucose, the Naegleria produced a limited growth parallelling the clearance of the lipid turbidity during a 72 hour incubation at 35 degrees C. Chromatographic analysis of the turbidity-cleared cultures revealed decomposition of sphingomyeline with liberation of choline, sphingosine and fatty acids. It is, hence, concluded that the pathogenicity of cytopathic effect of pathogenic Naegleria can be attributed to the latter's capacity to liberate a phospholipolytic enzyme or factor during active growth, which "makes holes" in the lipid-rich cytoplasmic membrane of cells as well as demyelinizes nerve tissue.
- MeSH
- amébiáza patologie MeSH
- Amoeba růst a vývoj metabolismus patogenita MeSH
- druhová specificita MeSH
- Haplorrhini MeSH
- krysa rodu Rattus MeSH
- kultivační techniky MeSH
- ledviny MeSH
- lidé MeSH
- meningoencefalitida patologie MeSH
- mozek patologie MeSH
- sfingomyeliny metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- sfingomyeliny MeSH
