title: Detailed analysis of an experimental challenge model for Leishmania infantum (JPC strain) in dogs.
abstract: In this study, disease progression after intravenous or subdermal infection of dogs with Leishmania infantum JPC strain was monitored. A challenge performed on 14 dogs via the intravenous route with 5 x 10(7) stationary phase promastigotes of the L. infantum JPC strain was 100% successful. During a follow up period of 1.5 years, several parameters were evaluated in order to find the most reliable disease markers. Parasite detection by culture and histology were found to be very sensitive (100%). Additionally, regular physical examination, serology and serum gamma-globulin levels were found to be useful parameters in the evaluation of disease severity and are recommended for inclusion in vaccination-challenge experiments. Although this intravenous challenge model has practical limitations, the data set confirms it is the best experimental model currently available for vaccine development. Two intravenously infected dogs were treated with corticosteroids for 5 months. This treatment was shown to enhance all aspects of a Leishmania infection. Five more dogs were infected by sub-dermal injection of promastigotes mixed with a proteophosphoglycan-matrix (PSG) secreted by Leishmania that assists in transmission and infection by sand fly bite. The resulting parasite burdens were low and the animals remained asymptomatic during a 2-year follow up period. However, this procedure did result in infection in 80% of the dogs and is appealing for future development as a natural challenge model in vaccine development.
authors.affiliation: Intervet International B.V., Parasitology R&D, Wim de Körverstraat 35, 5831 AN Boxmeer, The Netherlands. jacqueline.poot@intervet.com
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Poot
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Rogers
authors.forename: Paul A
authors.initials: PA
authors.lastname: Bates
authors.forename: Arno
authors.initials: A
authors.lastname: Vermeulen
mesh_terms: D000305:Adrenal Cortex Hormones / Q000276:immunology; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D049109:Cell Proliferation; D003907:Dexamethasone / Q000276:immunology; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000276:immunology / Q000469:parasitology* / Q000473:pathology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology; D018314:Leishmania infantum / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D008198:Lymph Nodes / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D008297:Male; D012313:RNA / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000469:parasitology; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D000305:Adrenal Cortex Hormones; D000913:Antibodies, Protozoan; D005719:gamma-Globulins; D012313:RNA; D003907:Dexamethasone; D007371:Interferon-gamma