Pathogenic potential of a Costa Rican strain of 'Candidatus Rickettsia amblyommii' in guinea pigs (Cavia porcellus) and protective immunity against Rickettsia rickettsii
Đã lưu trong:
| Nhiều tác giả: | , , , , , , , , |
|---|---|
| Định dạng: | artículo |
| Ngày xuất bản: | 2015 |
| Miêu tả: | Candidatus Rickettsia amblyommii' is a spotted fever group rickettsia that is not considered pathogenic, although there is serologic evidence of possible infection in animals and humans. The aim of this study was to evaluate the pathogenic potential of a Costa Rican strain of ' Candidatus R. amblyommii' in guinea pigs and determine its capacity to generate protective immunity against a subsequent infection with a local strain of Rickettsia rickettsii isolated from a human case. Six guinea pigs were inoculated with ' Candidatus R. amblyommii' strain 9-CC-3-1 and two controls with cell culture medium. Health status was evaluated, and necropsies were executed at days 2, 4, and 13. Blood and tissues were processed by PCR to detect the gltA gene, and end titers of anti-' Candidatus R. amblyommii' IgG were determined by indirect immunofluorescence. To evaluate protective immunity, another 5 guinea pigs were infected with ' Candidatus R. amblyommii' (IGPs). After 4 weeks, these 5 IGPs and 3 controls (CGPs) were inoculated with pathogenic R. rickettsii. Clinical signs and titers of anti-. Rickettsia IgG were determined. IgG titers reached 1:512 at day 13 post-infection with ' Candidatus R. amblyommii' On day 2 after inoculation, two guinea pigs had enlarged testicles and ' Candidatus R. amblyommii' DNA was detected in testicles. Histopathology confirmed piogranulomatous orchitis with perivascular inflammatory infiltrate in the epididymis. In the protective immunity assay, anti-. Rickettsia IgG end titers after R. rickettsii infection were lower in IGPs than in CGPs. IGPs exhibited only transient fever, while CGP showed signs of severe disease and mortality. R. rickettsii was detected in testicles and blood of CGPs. Results show that the strain 9-CC-3-1 of ' Candidatus R. amblyommii' was able to generate pathology and an antibody response in guinea pigs. Moreover, its capacity to generate protective immunity against R. rickettsii may modulate the epidemiology and severity of Rocky Mountain spotted fever in areas where both species circulate. |
| Quốc gia: | Repositorio UNA |
| Tổ chức giáo dục: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Ngôn ngữ: | Inglés |
| OAI Identifier: | oai:null:11056/17589 |
| Truy cập trực tuyến: | http://hdl.handle.net/11056/17589 https://doi.org/10.1016/j.ttbdis.2015.07.008 |
| Từ khóa: | COSTA RICA GUINEA PIG RICKETTSIA AMBLYOMMII INMUNOLOGÍA INMUNOLOGÍA VETERINARIA IMMUNITY EXPERIMENTAL INFECTION |