Urteekstrakter som bæredygtigt bekæmpelsesmiddel mod parasitter i økologisk fiskeopdræt

Opdræt af regnbueørred, særligt økologisk ørred, er udfordret på grund af gælle- og hudparasitinfektioner forårsaget af en række forskellige patogener. Det drejer sig især om mikroskopiske flagellater, fimredyr samt en række amøber. Da flere andre typer parasitter er følsomme over for indholdsstoffer i hvidløg, oregano og timian kunne ekstrakter fra disse krydderurter måske være en del af løsningen også for dambrugsfisk. Vore laboratorieforsøg viste, at fiskeparasitter faktisk var følsomme over for et eller flere indholdsstoffer i hvidløg, oregano og timian. Men det viste sig også, at det kun var timian og en biologisk sæbe fra bakterien Pseudomonas, som blev veltolereret af fiskene, mens ekstrakter af oregano og hvidløg ikke blev vel modtaget af regnbueørrederne. Timian-ekstrakt havde således antiparasitisk effekt, idet snylterne på fiskens hud døde og løsnedes fra både hud, finner og gæller. En andet stof, isoleret fra Pseudomonas H6 bakterien, som er en biologisk sæbe (en surfaktant, et overfladeaktivt molekyle), viste sig også at være effektiv mod flere typer parasitter

Prevalence and Diffusion of Gastrointestinal Parasite Infections in Swamp Water Buffalo (Bubalus Bubalis) Populations from Marshlands of Iraq

Background and objectives: New information on the epidemiology of gastrointestinal (GI) parasite infection in water buffaloes is crucial for understanding their risk factors and transmission. The objectives of this study were (1) to determine the prevalence of GI parasites in buffaloes in the Marshland areas of southern Iraq, and (2) to evaluate the association of risk factors with the parasitic infections.Materials and Methods: A total of 166 water buffaloes from the Marshland in the north of Basra (n=75), and Thi-Qar (n=91) provinces from November 2016 to April 2017 were enrolled. Fecal samples were collected and examined for the presence of helminth eggs and protozoal oocysts using sedimentation-flotation and centrifugal flotation techniques.Results: The overall prevalence of infection in buffaloes was 82% (136/166), with the highest number of single parasite infection (64%), followed by those with double (29%) and triple (7%) parasite infections. The most frequently identified parasites were Fasciola spp. (23%, 39/166), Eimeria spp. (19%, 32/166), Toxocara vitulorum (13%, 21/166), Trichostrongylus spp. (12%, 20/166), and Oesophagostomum spp. (10%, 10/166). Moniezia spp. was the only identified cestode with a prevalence of (8%, 13/166). A significant association was reported between feeding type and parasitic infections with Eimeria spp., Trichostrongylus spp., Moniezia spp., Trichuris spp., and Ostertagia ostertagia.Conclusion: The prevalence of GI parasitic infection in buffaloes raised in the Marshlands is high, indicating a high intensity of natural infection. The findings of this study imply an urgent need for the implementation of efficient control measures against parasitic infections in the Marshlands

Differential immune gene response in gills, skin, and spleen of rainbow trout <i>Oncorhynchus mykiss</i> infected by<i> Ichthyophthirius multifiliis</i>

Infection of rainbow trout with the parasitic ciliate Ichthyopthirius multifiliis induces differential responses in gills, skin and spleen. A controlled experimental infection was performed and expression of immune-relevant genes in skin, gills, and spleen were recorded by qPCR at day 1 and 8 after parasite exposure. Infection induced a marked reaction involving regulation of innate and adaptive immune genes in rainbow trout at day 8 post-infection. The expression level of a total of 22 out of 24 investigated genes was significantly higher in gills compared to skin reflecting the more sensitive and delicate structure of gills. Especially pro-inflammatory cytokines IL-6, IL-17 C1, regulatory cytokines IL-4/13A, IL-10, TGFβ, complement factor C5, chemokines CK10, CK12, acute phase proteins (precerebellin, hepcidin) and immunoglobulins (IgM, IgT) displayed differential expression levels. The spleen, a central immune organ with no trace of the parasite, showed elevated expression of IgM, IgT, complement factor C5 and chemokine CK10 (compared to skin and gills directly exposed to the parasite), indicating an interaction between the infected surface sites and central immune organs. This communication could be mediated by chemokines CK10 and CK12 and cytokine IL-4/13A and may at least partly explain the establishment of a systemic response in rainbow trout against the parasite