When parasites invade paired structures of their host non-randomly, the resulting asymmetry may have both pathological and ecological significance. To facilitate the detection and visualisation of asymmetric infections we have developed a free software tool, Analysis of Symmetry of Parasitic Infections (ASPI). This tool has been implemented as an R package (https://cran.r-project.org/package=aspi) and a web application (https://wayland.shinyapps.io/aspi). ASPI can detect both consistent bias towards one side, and inconsistent bias in which the left side is favoured in some hosts and the right in others. Application of ASPI is demonstrated using previously unpublished data on the distribution of metacercariae of species of Diplostomum von Nordmann, 1832 in the eyes of ruffe Gymnocephalus cernua (Linnaeus). Invasion of the lenses appeared to be random, with the proportion of metacercariae in the left and right lenses showing the pattern expected by chance. However, analysis of counts of metacercariae from the humors, choroid and retina revealed asymmetry between eyes in 38% of host fish., Matthew T. Wayland, James C. Chubb., and Obsahuje bibliografii
As part of a biodiversity study in northwestern Hungary, we conducted a parasitological survey of small mammals. In both common shrews (Sorex araneus Linnaeus) and pygmy shrews (Sorex minutus Linnaeus), we found myxospores of a species of Soricimyxum Prunescu, Prunescu, Pucek et Lom, 2007 (Myxosporea) and plasmodia in the bile ducts within the liver. Spores from both species of shrewswere morphologically and morphometrically indistinguishable, but differed in their SSU rRNA gene sequences by 3.3%. We identified spores and developmental stages from the common shrew as Soricimyxum fegati Prunescu, Prunescu, Pucek et Lom, 2007, based on morphometric data and DNA sequence similarity. Spores from the pygmy shrew were only 96.7% similar to S. fegati, hence we identified them as a novel myxosporean Soricimyxum minuti sp. n. This is only the second myxosporean parasite species described from mammals., Csaba Székely, Gábor Cech, Stephen D. Atkinson, Kálmán Molnár, László Egyed, András Gubányi., and Obsahuje bibliografii
Myxozoans (Cnidaria: Myxozoa) are almost exclusively endoparasites of aquatic vertebrates and invertebrates, with the notable exception being two species of Soricimyxum Prunescu, Prunescu, Pucek et Lom, 2007 described from terrestrial shrews (Soricidae) in central Europe. Myxospores of the two parasites are morphologically indistinguishable, but have SSU rDNA sequences that differ by about 4%. Herein, we report additional molecular and histology data from Soricimyxum fegati Prunescu, Prunescu, Pucek et Lom, 2007 from common shrew (Sorex araneus Linnaeus) from Hungary, and add a new geographic record for S. fegati in pygmy shrew (Sorex minutus Linnaeus) from Slovakia. A limited survey of shrews from the northern United States, Blarina brevicauda Say and Sorex sp. from New York, and Sorex spp. from Oregon, did not discover any infections, which is in stark contrast to the relatively high infection rates (up to 66%) in European shrew populations. We also provide a summary and discussion of literature records of species of Soricimyxum and a host survey. Given the lack of distinguishing morphological or morphometric characters between Soricimyxum spp., and the overlap in vertebrate hosts and geographic ranges, unambiguous identification of these closely related shrew parasites can presently only be achieved through sequence comparison of one or more variable SSU rDNA regions., Csaba Székely, Stephen D. Atkinson, Kálmán Molnár, László Egyed, András Gubányi, Gábor Cech., and Obsahuje bibliografii
The notifiable freshwater pathogen Gyrodactylus salaris Malmberg, 1957 tends to be a generalist in contrast to other monogeneans. Whilst it causes most damage to its primary host, the Atlantic salmon (Salmo salar Linnaeus), transport and reservoir hosts likely play a key role in maintaining the parasite in the environment. Here, we tested the ability of G. salaris (strain River Lierelva, southern Norway) to infect and reproduce on a population of wild caught alpine bullhead (Cottus poecilopus Heckel). Exposure of alpine bullhead yearlings (0+) to G. salaris for 24 h at low (6.5 °C) or high temperature (11.5 °C) resulted in the establishment of 1 to 104 parasites per fish. Eight to nine days post-infection at high temperature, the infection of G. salaris was eliminated, indicative of innate host immunity. In contrast, at low temperature G. salaris infections persisted for 47-48 days. The relative lengthy infection of alpine bullhead with G. salaris compared to other non-salmonids tested may be due to low temperature and high initial infection load in combination with an epibiont infection. The present results suggest that this non-salmonid may function as a temperature-dependent transport or reservoir host for G. salaris.
Tumour necrosis factor (TNF) plays a central role in the inflammatory process. In the skin, it contributes to immune containment of tick-transmitted pathogens like Borrelia burgdorferi. In the saliva of some tick species, active compounds are present that inhibit detection of TNF in specific ELISA. We compared the presence of anti-TNF activity in saliva or salivary gland extract from 11 tick species from the family Ixodidae and demonstrated it in genera Ixodes Latreille, 1795 and Haemaphysalis Koch, 1844. Analysis of anti-TNF activity in Ixodes ricinus (Linnaeus, 1758) saliva during the feeding period showed that it is present in the late, rapid phase of engorgement. Significance of anti-TNF activity for tick feeding and transmission of tick-borne pathogens is discussed., Markéta Rezková, Jan Kopecký., and Obsahuje bibliografii
Borrelia burgdorferi sensu lato (s.l.) is the etiological agent of Lyme disease, transmitted by ticks of the genus Ixodes Latreille. Diagnosis of Lyme disease in humans is often difficult and a detailed knowledge of the circulation of B. burgdorferi s.l. in tick hosts is therefore fundamental to support clinical procedures. Here we developed a molecular approach for the detection of B. burgdorferi s.l. in North Italian Ixodes ricinus (Linnaeus). The method is based on the amplification of a fragment of the groEL gene, which encodes a heat-shock protein highly conserved among B. burgdorferi s.l. species. The tool was applied in both qualitative and Real-time PCR approaches testing ticks collected in a North Italian area. The obtained results suggest that this new molecular tool could represent a sensitive and specific method for epidemiological studies aimed at defining the distribution of B. burgdorferi s.l. in I. ricinus and, consequently, the exposure risk for humans.
Alveolar echinococcosis is a severe chronic helminthic disease that mimics slow-growing liver cancer. The immune evasion strategy of Echinococcus multilocularis Leuckart, 1863 remains poorly understood. The aim of this study was to investigate in vitro the impact of E. multilocularis vesicular fluid (Em-VF) on peripheral blood mononuclear cells (PBMC) and on natural killer (NK) cells. PBMC and NK cells were exposed to Em-VF (1 µg/ml) during six days. The effect of Em-VF was assessed on CD69, viability and proliferation, and on and transforming growth factor β (TGF-β), interferon γ (IFN-γ), interleukin 17 (IL-17) and interleukin 10, using flow cytometry and ELISA, respectively. Exposure to Em-VF had no bearing on PBMC's viability, proliferation and expression of CD69. In contrast, higher levels of IL-17 at day three and of TGF-β at day six were observed in PBMC supernatant after exposure to Em-VF (p < 0.05, Wilcoxon signed-rank test). Exposure to Em-VF induced a significant decrease of CD69 expression of NK cells at day three and a significant decrease of proliferation of NK cells at day six (p < 0.05, Wilcoxon signed-rank test). In contrast, NK cells viability and levels of cytokines did not vary significantly over Em-VF stimulation. Exposure to Em-VF had a significant bearing on activation and proliferation of NK cells. NK cells may play an important role in the immune response of the host against E. multilocularis., Anne-Pauline Bellanger, Valentine Mougey, Jean-René Pallandre, Houssein Gbaguidi-Haore, Yann Godet, Laurence Millon., and Obsahuje bibliografii
Taeniosis-cysticercosis caused by Taenia crassiceps (Zeder, 1800) is a useful experimental model for biomedical research, in substitution of Taenia solium Linnaeus, 1758, studied during decades to develop effective vaccination, novel anti-helminthic drugs and diagnostic tools. Cysticercosis in mouse (Mus musculus Linnaeus) is achieved by the larval subculturing of the Wake Forest University (WFU) strain of T. crassiceps. Golden hamster, Mesocricetus auratus (Waterhouse), has been shown to be the most suitable host for adult forms of parasite in experimental taeniosis. Metacestodes of T. crassiceps WFU multiply by budding without restrictions once inoculated into the mouse, while the number of tapeworms developed from these larvae in hamsters remains highly variable. Three objectives have been proposed to improve the infection of T. crassiceps WFU in hamsters: (1) to re-evaluate the need of immune suppression; (2) to investigate the advantage of infecting hamsters with metacestodes with in vitro protruded scolices; and (3) to compare a number of tapeworms developed from metacestodes subcultured in hamsters against those proliferated in mice. Our results demonstrated that when the evagination of murine metacestodes was high, the number of T. crassiceps WFU adults obtained from hamsters was also high. Immunosuppressive treatment remains relevant for this experimental rodent model. The hamster-to-hamster cysticercosis-taeniosis by T. crassiceps overcame the mouse-to-hamster model in the yield of adult specimens. In vitro scolex evagination and metacestode asexual proliferation in hamsters place this rodent model by T. crassiceps WFU as the most affordable experimental models with taeniids.
Copepods of the genus Achtheinus Wilson, 1908 (Pandaridae) are parasites of elasmobranchs that attach to their fins, gill slits and around the nostrils. Specimens of Achtheinus pinguis Wilson, 1912 were collected and examined using histology and scanning electron microscopy to determine their way of attachment to the host and the possible effect on the host. They insert their antennae deep into the dermis of the shark's skin, which causes the most damage due to possible tissue compression and/or fibrosis as well as rupture of the connective tissue. Additionally, the presence of the copepod on the skin causes cell erosion of the epidermal cells and thus reduces the number of epidermal layers. The maxillipeds are used to attach to the placoid scales that cover the shark's skin and probably serve to keep the copepod and inserted antennae in position. This is accomplished by the insertion of the placoid scales into the flaccid corpus of the maxillipeds. Observed damage seems to be negligible to the shark apart from the possibility of secondary infection., Susan M. Dippenaar, Anine Jordaan., and Obsahuje bibliografii
Ichthyophthirius multifiliis Fouquet, 1876, a ciliate parasite, is a cosmopolitan and problematic parasite of cultured freshwater fish. Each geographical isolate of I. multifiliis has variations in life cycle timing under different abiotic water conditions, such as temperature and salinity. We assessed the effects of salinity and temperature on the development and the preferred settlement site of a temperate Australian isolate of I. multifiliis. The time until theront release was significantly different between each temperature; development time was longest at 5 °C with a mean time of 189 h and decreased to a mean time of 11.7 h at 30 °C. At 5 °C our isolate produced a mean of 267 theronts per tomont, which increased to a mean of 493 theronts at 25 °C and reduced to a mean of 288 theronts at 30 °C. Theront length showed an inverse relationship to temperature; mean length was 62 μm at 5 °C and 41 μm at 30 °C. Our isolate reproduced faster at all temperatures and a greater sensitivity to salinity than all reported profiles for temperate isolates. Parasite abundance was highest on the dorsal region of the fish. An accurate understanding of temperature-life cycle information and optimal region to sample for surveillance will aid in the development of specific management plans for the Australian isolate of I. multifiliis, facilitating the strategic timing of treatments., James M. Forwood, James O. Harris, Matt Landos, Marty R. Deveney., and Obsahuje bibliografii