Edmour F. Blouin

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The tick-borne intracellular pathogen Anaplasma marginale (Rickettsiales: Anaplasmataceae) develops persistent infections in cattle and tick hosts. While erythrocytes appear to be the only site of infection in cattle, A. marginale undergoes a complex developmental cycle in ticks and transmission occurs via salivary glands during feeding. Many geographic(More)
The gene that encodes the tick protective antigen, 4D8, was cloned from 10 species belonging to 6 genera, and the nucleotide and amino acid sequences were analyzed. 4D8 nucleotide and protein sequences were conserved among these tick species with identity/similarity between 65-98 and 60-98%, respectively. The function of 4D8 was characterized by RNA(More)
The coevolution of ticks and the pathogens that they transmit has ensured their mutual survival. In these studies, we used a functional genomics approach to characterize tick genes regulated in response to Anaplasma marginale infection. Differentially regulated genes/proteins were identified by suppression-subtractive hybridization and differential in-gel(More)
We characterized the effects of subolesin and heat shock protein (HSP) expression on Ixodes scapularis Say (Acari: Ixodidae) stress responses to heat shock and feeding, questing behaviour and Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) infection. Ticks and cultured tick cells were analysed before and after subolesin, hsp20 and hsp70 gene(More)
Over 40 cell lines are currently available from 13 ixodid and one argasid tick species. The successful isolation and propagation of several economically important tick-borne pathogens in tick cell lines has created a useful model to study interactions between tick cells and these viral and bacterial disease agents. Tick cell lines have already proved to be(More)
Anaplasma marginale, an ehrlichial pathogen of cattle and wild ruminants, is transmitted biologically by ticks. A developmental cycle of A. marginale occurs in a tick that begins in gut cells followed by infection of salivary glands, which are the site of transmission to cattle. Geographic isolates of A. marginale vary in their ability to be transmitted by(More)
Anaplasma marginale is a tick-borne rickettsia that causes bovine anaplasmosis worldwide. Despite its importance, A. marginale has thus far not been established in a continuous culture system. We have propagated A. marginale continuously for the 1st time in a tick cell line derived from the black-legged tick, Ixodes scapularis Say, using infected bovine(More)
Ehrlichia chaffeensis Anderson, Dawson & Wilson, causative agent of human (predominantly monocytic) ehrlichiosis, was successfully transmitted experimentally by Amblyomma americanum (L.) to white-tailed deer, Odocoileus virginianus (Zimmerman). Deer were needle-exposed intravenously to E. chaffeensis in tissue-culture canine macrophage (DH82) cells, and 11(More)
The major surface protein (MSP) 1a of the ehrlichial cattle pathogen Anaplasma marginale, encoded by the single-copy gene msp1alpha, has been shown to have a neutralization-sensitive epitope and to be an adhesin for bovine erythrocytes and tick cells. msp1alpha has been found to be a stable genetic marker for the identification of geographic isolates of A.(More)