Cargando…

Experimental infection of horses with Rickettsia rickettsii

BACKGROUND: Rickettsia rickettsii is vectored by ticks, and some vertebrate hosts can be sources of infection to ticks during bacteremic periods. In Brazil, the main vector for R. rickettsii is the tick Amblyomma sculptum, a member of the A. cajennense complex. Horses, in turn, are one of the major...

Descripción completa

Detalles Bibliográficos
Autores principales: Ueno, Tatiana Evelyn Hayama, Costa, Francisco B., Moraes-Filho, Jonas, Agostinho, Washington Carlos, Fernandes, Wilson Roberto, Labruna, Marcelo B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5022194/
https://www.ncbi.nlm.nih.gov/pubmed/27624315
http://dx.doi.org/10.1186/s13071-016-1784-y
_version_ 1782453475368501248
author Ueno, Tatiana Evelyn Hayama
Costa, Francisco B.
Moraes-Filho, Jonas
Agostinho, Washington Carlos
Fernandes, Wilson Roberto
Labruna, Marcelo B.
author_facet Ueno, Tatiana Evelyn Hayama
Costa, Francisco B.
Moraes-Filho, Jonas
Agostinho, Washington Carlos
Fernandes, Wilson Roberto
Labruna, Marcelo B.
author_sort Ueno, Tatiana Evelyn Hayama
collection PubMed
description BACKGROUND: Rickettsia rickettsii is vectored by ticks, and some vertebrate hosts can be sources of infection to ticks during bacteremic periods. In Brazil, the main vector for R. rickettsii is the tick Amblyomma sculptum, a member of the A. cajennense complex. Horses, in turn, are one of the major hosts for A. sculptum. In this study, horses experimentally infected with R. rickettsii were assessed for clinical changes and their capability to transmit the infection to A. sculptum ticks. METHODS: Four horses were infected with R. rickettsii through either intraperitoneal injection or infestation with R. rickettsii-infected A. sculptum ticks. Simultaneously, the animals were infested with non-infected A. sculptum ticks. The horses were monitored for 30 days by clinical examination, hematological and biochemical tests, real-time PCR of blood for the detection of Rickettsia, and inoculation of blood in guinea pigs. IgG antibody titers were followed until the horses have shown seronegativity or until the end of the experiment. Uninfected ticks that fed on horses were subjected to real-time PCR and/or were fed on susceptible rabbits. RESULTS: The horses showed no clinical, hematological or blood biochemical alterations, and bacteremia was not detected by real-time PCR or by inoculation of horse blood into guinea pigs. Anti-R. rickettsii antibodies were detected in horses from 10 days to 2 years after infection. Uninfected ticks, after feeding on infected horses, showed 2.1 % positivity in real-time PCR, but failed to transmit the infection to rabbits at a next feeding stage. CONCLUSIONS: Rickettsia rickettsii-infected horses did not manifest illness and are not competent amplifier hosts of R. rickettsii for A. sculptum ticks.
format Online
Article
Text
id pubmed-5022194
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-50221942016-09-20 Experimental infection of horses with Rickettsia rickettsii Ueno, Tatiana Evelyn Hayama Costa, Francisco B. Moraes-Filho, Jonas Agostinho, Washington Carlos Fernandes, Wilson Roberto Labruna, Marcelo B. Parasit Vectors Research BACKGROUND: Rickettsia rickettsii is vectored by ticks, and some vertebrate hosts can be sources of infection to ticks during bacteremic periods. In Brazil, the main vector for R. rickettsii is the tick Amblyomma sculptum, a member of the A. cajennense complex. Horses, in turn, are one of the major hosts for A. sculptum. In this study, horses experimentally infected with R. rickettsii were assessed for clinical changes and their capability to transmit the infection to A. sculptum ticks. METHODS: Four horses were infected with R. rickettsii through either intraperitoneal injection or infestation with R. rickettsii-infected A. sculptum ticks. Simultaneously, the animals were infested with non-infected A. sculptum ticks. The horses were monitored for 30 days by clinical examination, hematological and biochemical tests, real-time PCR of blood for the detection of Rickettsia, and inoculation of blood in guinea pigs. IgG antibody titers were followed until the horses have shown seronegativity or until the end of the experiment. Uninfected ticks that fed on horses were subjected to real-time PCR and/or were fed on susceptible rabbits. RESULTS: The horses showed no clinical, hematological or blood biochemical alterations, and bacteremia was not detected by real-time PCR or by inoculation of horse blood into guinea pigs. Anti-R. rickettsii antibodies were detected in horses from 10 days to 2 years after infection. Uninfected ticks, after feeding on infected horses, showed 2.1 % positivity in real-time PCR, but failed to transmit the infection to rabbits at a next feeding stage. CONCLUSIONS: Rickettsia rickettsii-infected horses did not manifest illness and are not competent amplifier hosts of R. rickettsii for A. sculptum ticks. BioMed Central 2016-09-13 /pmc/articles/PMC5022194/ /pubmed/27624315 http://dx.doi.org/10.1186/s13071-016-1784-y Text en © The Author(s). 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Ueno, Tatiana Evelyn Hayama
Costa, Francisco B.
Moraes-Filho, Jonas
Agostinho, Washington Carlos
Fernandes, Wilson Roberto
Labruna, Marcelo B.
Experimental infection of horses with Rickettsia rickettsii
title Experimental infection of horses with Rickettsia rickettsii
title_full Experimental infection of horses with Rickettsia rickettsii
title_fullStr Experimental infection of horses with Rickettsia rickettsii
title_full_unstemmed Experimental infection of horses with Rickettsia rickettsii
title_short Experimental infection of horses with Rickettsia rickettsii
title_sort experimental infection of horses with rickettsia rickettsii
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5022194/
https://www.ncbi.nlm.nih.gov/pubmed/27624315
http://dx.doi.org/10.1186/s13071-016-1784-y
work_keys_str_mv AT uenotatianaevelynhayama experimentalinfectionofhorseswithrickettsiarickettsii
AT costafranciscob experimentalinfectionofhorseswithrickettsiarickettsii
AT moraesfilhojonas experimentalinfectionofhorseswithrickettsiarickettsii
AT agostinhowashingtoncarlos experimentalinfectionofhorseswithrickettsiarickettsii
AT fernandeswilsonroberto experimentalinfectionofhorseswithrickettsiarickettsii
AT labrunamarcelob experimentalinfectionofhorseswithrickettsiarickettsii