TY  - JOUR
AB  - BACKGROUND: The Gran Chaco ecoregion is a well-known hotspot of several neglected tropical diseases (NTDs) including Chagas disease, soil-transmitted helminthiasis and multiparasitic infections. Interspecific interactions between parasite species can modify host susceptibility, pathogenesis and transmissibility through immunomodulation. Our objective was to test the association between human co-infection with intestinal parasites and host parasitaemia, infectiousness to the vector and immunological profiles in Trypanosoma cruzi-seropositive individuals residing in an endemic region of the Argentine Chaco. METHODS: We conducted a cross-sectional serological survey for T. cruzi infection along with an intestinal parasite survey in two adjacent rural villages. Each participant was tested for T. cruzi and Strongyloides stercoralis infection by serodiagnosis, and by coprological tests for intestinal parasite detection. Trypanosoma cruzi bloodstream parasite load was determined by quantitative PCR (qPCR), host infectiousness by artificial xenodiagnosis and serum human cytokine levels by flow cytometry. RESULTS: The seroprevalence for T. cruzi was 16.1% and for S. stercoralis 11.5% (n = 87). We found 25.3% of patients with Enterobius vermicularis. The most frequent protozoan parasites were Blastocystis spp. (39.1%), Giardia lamblia (6.9%) and Cryptosporidium spp. (3.4%). Multiparasitism occurred in 36.8% of the examined patients. Co-infection ranged from 6.9% to 8.1% for T. cruzi-seropositive humans simultaneously infected with at least one protozoan or helminth species, respectively. The relative odds of being positive by qPCR or xenodiagnosis (i.e. infectious) of 28 T. cruzi-seropositive patients was eight times higher in people co-infected with at least one helminth species than in patients with no such co-infection. Trypanosoma cruzi parasite load and host infectiousness were positively associated with helminth co-infection in a multiple regression analysis. Interferon-gamma (IFN-γ) response, measured in relation to interleukin (IL)-4 among humans infected with T. cruzi only, was 1.5-fold higher than for T. cruzi-seropositive patients co-infected with helminths. The median concentration of IL-4 was significantly higher in T. cruzi-seropositive patients with a positive qPCR test than in qPCR-negative patients. CONCLUSIONS: Our results show a high level of multiparasitism and suggest that co-infection with intestinal helminths increased T. cruzi parasitaemia and upregulated the Th2-type response in the study patients.
AU  - Enriquez, G.F.*
AU  - Macchiaverna, N.P.*
AU  - Garbossa, G.*
AU  - Quebrada Palacio, L.P.
AU  - Ojeda, B.L.*
AU  - Bua, J.*
AU  - Gaspe, M.S.*
AU  - Cimino, R.*
AU  - Gürtler, R.E.*
AU  - Postan, M.*
AU  - Cardinal, M.V.*
C1  - 71464
C2  - 56197
CY  - Campus, 4 Crinan St, London N1 9xw, England
TI  - Humans seropositive for Trypanosoma cruzi co-infected with intestinal helminths have higher infectiousness, parasitaemia and Th2-type response in the Argentine Chaco.
JO  - Parasit. Vectors
VL  - 17
IS  - 1
PB  - Bmc
PY  - 2024
ER  - 

TY  - JOUR
AB  - BACKGROUND: The lungworm Dictyocaulus viviparus, causing parasitic bronchitis in cattle, induces a temporary protective immunity that prevents clinical disease. A radiation-attenuated larvae based vaccine is commercially available in a few European countries, but has the disadvantages of a live vaccine. As a recombinant subunit vaccine would overcome these disadvantages, the parasite's muscle protein paramyosin (PMY) was tested as a recombinant vaccine antigen. METHODS: D. viviparus-PMY was recombinantly expressed in Escherichia coli as a glutathione-S-transferase (GST)-fused protein. Emulsified in adjuvant Saponin Quil A, the protein was given intramuscularly into calves. Two independent recombinant PMY (rPMY) vaccination trials with negative control groups (first trial: adjuvant only; second trial: non-fused GST) as well as an additional positive control group in the second trial, using the Bovilis(©)Dictol live vaccine to verify vaccination results, were performed. To determine the vaccination success, shedding of larvae as well as worm burden and worm sizes were analyzed. Additionally, ELISA-based determination of development of immunglobulins IgM, IgA, IgE, IgG as well as the subclasses IgG1 and IgG2 was performed. To analyze PMY localization in the bovine lungworm, immunohistochemical staining of adult worms was carried out. RESULTS: Immunohistochemical staining revealed that PMY is part of the bovine lungworm's pharyngeal and body wall muscles. Vaccination with rPMY resulted in 47% [geometric mean: 67%] and 57% (geometric mean: 71%) reduction of larvae shedding in the first and second vaccination trial, respectively. Worm burden was reduced by 54% (geometric mean: 86%) and 31% (geometric mean: 68%), respectively, and worms of rPMY-vaccinated cattle were significantly shorter in both trials. Furthermore, ELISAs showed a clear antibody response towards rPMY with exception of IgE for which titers could not be detected. After challenge infection, rPMY antibodies were only exceptionally elevated among study animals indicating PMY to be a hidden antigen. CONCLUSIONS: Even though vaccination with the attenuated live vaccine was with 94% (geometric mean: 95%) reduction in larvae shedding and 93% (geometric mean: 94%) reduction in worm burden superior to rPMY vaccination, results using the latter are promising and show the potential for further development of a recombinant PMY-based vaccine against the bovine lungworm.
AU  - Strube, C.*
AU  - Haake, C.*
AU  - Sager, H.*
AU  - Schorderet Weber, S.*
AU  - Kaminsky, R.*
AU  - Buschbaum, S.*
AU  - Joekel, D.*
AU  - Schicht, S.*
AU  - Kremmer, E.
AU  - Korrell, J.*
AU  - Schnieder, T.*
AU  - von Samson-Himmelstjerna, G.*
C1  - 44436
C2  - 36835
CY  - London
TI  - Vaccination with recombinant paramyosin against the bovine lungworm Dictyocaulus viviparus considerably reduces worm burden and larvae shedding.
JO  - Parasit. Vectors
VL  - 8
IS  - 1
PB  - Biomed Central Ltd
PY  - 2015
ER  - 

TY  - JOUR
AB  - Little information is available on the immunological aspect of parasitic Gasterophilus intestinalis (Diptera, Oestridae) larvae causing horse gastric myiasis. The objectives of this research were to analyze the protein content of larval crude extracts of the migrating second and third larvae (L2 and L3) of G. intestinalis in order to characterize the immune response of horses. Results: The proteomic profile of L2 and L3, investigated by using one and two dimensional approaches, revealed a migration pattern specific to each larval stage. Furthermore, Western blots were performed with horse sera and with sera of Balb/c mice immunised with the larval crude extracts of L2 or L3, revealing a different immune reaction in naturally infected horses vs. artificially induced immune reaction in mice. The comparisons of the immunoblot profiles demonstrate that the stage L2 is more immunogenic than the stage L3 most likely as an effect of the highest enzymatic production of L2 while migrating through the host tissues. Fifteen proteins were identified by mass spectrometry. Conclusion: This work provides further information into the understanding of the interaction between G. intestinalis and their host and by contributing a novel scheme of the proteomic profile of the main larval stages.
AU  - Roelfstra, L.*
AU  - Deeg, C.A.*
AU  - Hauck, S.M.
AU  - Buse, C.*
AU  - Membrez, M.*
AU  - Betschart, B.*
AU  - Pfister, K.*
C1  - 1681
C2  - 26960
TI  - Protein expression profile of Gasterophilus intestinalis larvae causing horse gastric myiasis and characterization of horse immune reaction.
JO  - Parasit. Vectors
VL  - 2
IS  - 1
PB  - Biomed Central Ltd
PY  - 2009
ER  -