Persistence mechanisms in tick-borne diseases.
Onderstepoort J Vet Res
; 76(1): 53-8, 2009 Mar.
Article
en En
| MEDLINE
| ID: mdl-19967928
ABSTRACT
The use of new, highly sensitive diagnostic methods has revealed persistent infections to be a common feature of different tick-borne diseases, such as babesiosis, anaplasmosis and heartwater. Antigenic variation can contribute to disease persistence through the continual elaboration of new surface structures, and we know in several instances how this is achieved. Known or suspected mechanisms of persistence in babesial parasites include cytoadhesion and rapid variation of the adhesive ligand in Babesia bovis and genetic diversity in several merozoite stage proteins of different Babesia spp. In Anaplasma, extensive variation in the pfam01617 gene family accompanies cycling of organism levels in chronic infection. One result from the pioneering research at Onderstepoort is the definition of a related polymorphic gene family that is likely involved in immunity against heartwater disease. We are beginning to understand the sizes of the antigenic repertoires and full definition is close, with the possibility of applying simultaneous high-throughput sequencing to the order of 1000 small genomes. We also, for the first time, can consider modifying these genomes and looking at effects on persistence and virulence. However, important biological questions remain unanswered; for example, why we are seeing a new emerging Anaplasma infection of humans and is infection of endothelial cells by Anaplasma significant to persistence in vivo.
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Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_zoonosis
Asunto principal:
Variación Genética
/
Ehrlichia ruminantium
/
Babesia bovis
/
Enfermedades por Picaduras de Garrapatas
/
Anaplasma
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Onderstepoort J Vet Res
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos