652 research outputs found
Serodiagnosis of Echinococcus spp. infection: explorative selection of diagnostic antigens by peptide microarray
No full textBACKGROUND: Production of native antigens for serodiagnosis of helminthic infections is laborious and hampered by batch-to-batch variation. For serodiagnosis of echinococcosis, especially cystic disease, most screening tests rely on crude or purified Echinococcus granulosus hydatid cyst fluid. To resolve limitations associated with native antigens in serological tests, the use of standardized and highly pure antigens produced by chemical synthesis offers considerable advantages, provided appropriate diagnostic sensitivity and specificity is achieved.
METHODOLOGY/PRINCIPAL FINDINGS: Making use of the growing collection of genomic and proteomic data, we applied a set of bioinformatic selection criteria to a collection of protein sequences including conceptually translated nucleotide sequence data of two related tapeworms, Echinococcus multilocularis and Echinococcus granulosus. Our approach targeted alpha-helical coiled-coils and intrinsically unstructured regions of parasite proteins potentially exposed to the host immune system. From 6 proteins of E. multilocularis and 5 proteins of E. granulosus, 45 peptides between 24 and 30 amino acids in length were designed. These peptides were chemically synthesized, spotted on microarrays and screened for reactivity with sera from infected humans. Peptides reacting above the cut-off were validated in enzyme-linked immunosorbent assays (ELISA). Peptides identified failed to differentiate between E. multilocularis and E. granulosus infection. The peptide performing best reached 57% sensitivity and 94% specificity. This candidate derived from Echinococcus multilocularis antigen B8/1 and showed strong reactivity to sera from patients infected either with E. multilocularis or E. granulosus.
CONCLUSIONS/SIGNIFICANCE: This study provides proof of principle for the discovery of diagnostically relevant peptides by bioinformatic selection complemented with screening on a high-throughput microarray platform. Our data showed that a single peptide cannot provide sufficient diagnostic sensitivity whereas pooling several peptide antigens improved sensitivity; thus combinations of several peptides may lead the way to new diagnostic tests that replace, or at least complement conventional immunodiagnosis of echinococcosis. Our strategy could prove useful for diagnostic developments in other pathogens
[Cyst-forming Coccidia: Toxoplasma, Neospora, Sarcocystis].
No full textThe most important cyst-forming coccidian parasites in human and veterinary medicine belong the genera of Toxoplasma, Neospora and Sarcocystis. Toxoplasma gondii shows its clinical relevance in congenital infections and opportunistic infections in immunodeficient patients. In veterinary medicine the parasite is predominantly the cause of important economic loss in livestock production. Neospora causes diseases resembling toxoplasmosis; neosporosis is one of the most important causes of bovine abortion in the US. Neospora caninum leads to myositis and paralysis in dogs. The potential implication of Neospora in toxoplasmosis-like diseases in humans is not yet known. Sarcocystis is usually a relatively harmless intestinal parasite in humans. Recent data from tropical areas suggest that man can also become an intermediate host for certain Sarcocystis species, which potentially represents a source of opportunistic infection and disease in areas with increasing HIV prevalence. In veterinary medicine, Sarcocystis causes muscle diseases and also abortion or myeloencephalitis with lethal outcome in certain animal species. Molecular-epidemiological investigations have resulted in a new understanding of biological and population-genetic mechanisms relevant to the disease. Recently developed molecular techniques, such as transfection in protozoan parasites, are presently used not only to elucidate molecular-pathogenetic events in the course of disease, but also to prepare potential new immuno-therapeutic tools for future vaccination against infection or disease
Protective immune mechanisms against the metacestode of Echinococcus multilocularis.
No full textInfection with the larval stage of the fox tapeworm Echinococcus multilocularis results in a life-threatening hepatic disease concerning humans and intermediate rodent hosts. Immunoepidemiological surveys provided information that a large proportion of infected individuals may demonstrate either constitutional resistance to early post-oncospheral development of the parasite or late resistance to disease by exhibiting an intrahepatic died-out parasite lesion. Similar events have been found in secondary infections of laboratory rodents. Dissection of humoral and cell-mediated immune responses in susceptible versus resistant individuals provides insight into immunological pathways associated with the different outcome of infection. Survival strategy of the metacestode obviously focuses on the crucial role played by the parasite laminated layer. This layer protects the metacestode from host effector mechanisms which can potentially kill the proliferating germinative compartments in case of resistant hosts. Bruno Gottstein and Richard Felleisen here discuss the need to search for more parameters discriminating between the different immune pathways in order to find out (immunogenetic?) predispositions responsible for the respective phenomena
Alpioniscus (Illyrionethes) lossinii Bedek & Gottstein & Taiti 2019, n. sp.
No full textAlpioniscus (Illyrionethes) lossinii n. sp. (Figs 5–8, 15) http://zoobank.org/ 47E3E7D2-262F-4D2C-B50E-3C3322043DC2 Alpioniscus strasseri. —Bedek et al. 2011: 278 (partim: Medvjeđa špilja). Alpioniscus (Illyrionethes) sp. 2.— Bedek et al. 2019: figs 3, 5. Material examined. Croatia, Croatian Littoral, Mali Lošinj Island: Holotype male Ćunski, Rt. Lokvica, Medvjeđa špilja (cave), 44.6055°N, 14.4079°E, 25–28 March 2010, leg. J. Bedek (CBSSC IT4224). Paratypes. 4 males, 1 male juv., 13 females, 3 juvs, same data as holotype (CBSSC IT2397); 1 male, 8 females, same locality, 20 March 2005, leg. J. Bedek (CBSSC IT2398); 2 males, 2 females, same locality and date, leg. M. Lukić (MZUF 9846); 3 males, 5 females, same locality, 6 March 2010, leg. B. Jalžić (CBSSC IT2400); 1 male, same locality, 2 March 2010, leg. J. Bedek (CBSSC IT2402). Description. Maximum length: male, 4.9 mm; female, 5.3 mm. Colourless body, pereon with almost parallel sides, pleon narrower than pereon (Fig. 5A,B). Dorsum granulated, with ridges near posterior margins of cephalon, pereonites and pleonites 1–2, and some triangular scale-setae (Fig. 5C). Some gland pores on lateral margins of pleonites 4, 5 and telson (Fig. 5E). Cephalon (Fig. 5D) with suprantennal line bent downwards in middle; antennal lobes rounded. Eyes absent. Posterior margin of pereonite 1 convex, of pereonites 2, 3 straight, and of pereonites 4–7 progressively more concave (Fig. 5A). Pleonites 3–5 with small posterior points visible in dorsal view (Fig. 5E). Distal part of telson with concave sides and broadly rounded apex (Fig. 5E). Antennula (Fig. 5F) of three articles, distal article bearing five to seven aesthetascs. Antenna (Fig. 5G) with peduncle granulated; flagellum of eight to 10 articles with one row of aesthetascs on four to five different articles, always on a second and third article. Buccal pieces (Fig. 6) as in A. magnus. Pereopods similar in shape, ungual seta simple, dactylar seta bifid and setose (Fig. 7A). Uropod (Fig. 5E) with protopod slightly grooved on outer margin; endopod distinctly shorter than exopod, proximally inserted. Male: Pereopod 1 (Fig. 7A) carpus bearing five to six setae. Pereopod 1 and 2 with propodus and carpus bearing numerous short scales on rostral surface. Pereopods 5 and 6 with small lobe proximally on sternal margin. Pereopod 7 (Fig. 7B,C) ischium with straight sternal margin; merus with slightly concave sternal margin and proximally with small hookshaped lobe bearing up to five triangular scales and one large seta; carpus with straight sternal and tergal margins. Genital papilla (Fig. 8A) with rounded apical part. Pleopod 1 (Fig. 8A) exopod with distal part narrow and rounded apex, concave outer margin, slightly convex inner margin; endopod narrow, triangular, armed with long apical plumose seta. Pleopod 2 (Fig. 8B) exopod subtriangular with slightly concave outer margin; endopod of two articles, slightly longer than exopod, distal article with posterior part narrower with strong and subapically bifid terminal seta. Pleopod 3–5 exopods as in Fig. 8 C–E. Etymology. The species is named after the island of Lošinj (Lat. Lossinium). Remarks. The new species is characterized by the lack of a hump on the tergal margin of the male pereopod 7 carpus, together with A. (I.). haasi (Verhoeff, 1931b), A. (I.) heroldi (Verhoeff, 1931a), A. (I.) herzegowinensis (Verhoeff, 1931a), A. (I.) kratochvili (Frankenberger, 1938), A. (I.) tuberculatus (Frankenberger, 1939), A. (I.) verhoeffi (Strouhal, 1938) and the two new species described below, A. (I.) drazinai and A. (I.) mandalinae. It differs from all these species by the narrow distal part of the male pleopod 1 exopod; from A. (I.) heroldi and A. (I.) herzegowinensis also in the shape of the hook on the male pereopod 7 merus.Published as part of Bedek, Jana, Gottstein, Sanja & Taiti, Stefano, 2019, Taxonomy of Alpioniscus (Illyrionethes): A. magnus and three new species from the Dinaric Karst (Isopoda: Oniscidea: Trichoniscidae), pp. 483-502 in Zootaxa 4657 (3) on pages 489-491, DOI: 10.11646/zootaxa.4657.3.4, http://zenodo.org/record/337196
Trichinella spp.: differential expression of two genes in the muscle larva of encapsulating and nonencapsulating species.
No full textKuratli, S., Lindh, J. G., Gottstein, B., Smith, D. F., and Connolly, B. 1999. Trichinella spp.: Differential expression of two genes in the muscle larva of encapsulating and nonencapsulating species. Experimental Parasitology 93, 153-159. The expression of the two genes tsmyd-1 and tsJ5 was studied in the muscle stage larva of three different species of Trichinella. T. spiralis and T. britovi are both encapsulating species, while T. pseudospiralis is a nonencapsulating species. Expression of tsJ5 is developmentally regulated in T. spiralis and has been shown in this study to be down-regulated in the T. pseudospiralis muscle larva compared with the other two species. Immunoblot analysis has also revealed that the relative abundance of the protein product of this gene, TSJ5, is lower in T. pseudospiralis muscle larvae. It has previously been shown that expression of tsmyd-1 is not developmentally regulated in T. spiralis (Connolly et al. 1996). In contrast, expression of this gene is slightly increased in the muscle larvae of T. pseudospiralis. Southern analysis of genomic DNA from the three Trichinella species shows that both genes are highly conserved
Immunization of rhesus macaques with Echinococcus multilocularis recombinant 14-3-3 antigen leads to specific antibody response.
No full textE. multilocularis (Em) is the etiologic agent of alveolar echinococcosis (AE), a severe and potentially fatal disease, primarily affecting the liver of and occurring in aberrant intermediate hosts, e.g., humans and non-human primates. Due to increasing numbers of spontaneous cases of AE in the Old World monkey colonies of the German Primate Center, the question arose as to whether vaccination of non-human primates may represent a useful prophylactic approach. In this pilot study, the recombinant antigen Em14-3-3, which has provided a 97 % protection against E. multilocularis challenge infection in rodent models, was used for the first time to immunize rhesus macaques. In order to increase immunogenicity, the antigen was formulated with different adjuvants including Quil A®, aluminum hydroxide (alum), and muramyl dipeptide (MDP). Also, different vaccination regimens were tested. All vaccinated animals developed antigen-specific antibodies. While Quil A® induced a local adverse reaction, alum proved to be the most potent adjuvant in terms of induced antibody levels, longevity as well as tolerability. In conclusion, our pilot study demonstrated that recombinant Em14-3-3 is safe and immunogenic in rhesus monkeys. As a next step, efficacy of the vaccination remains to be explored
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