Anaplasma (Ehrlichia) phagocytophila and Ehrlichia chaffeensis, the etiologic agents of granulocytic and monocytic ehrlichioses, respectively, are obligatory intracellular bacteria that cause febrile systemic illness in humans. We identified and characterized clusters of genes for a type IV secretion machinery in these two bacteria, and analyzed their gene expression in cell culture and mammali...

1. Paddock CD, Childs JE. Ehrlichia chaffeensis: a prototypical emerging pathogen. Clin Microbiol Rev. 2003;16:37–64. 2. Arraga-Alvarado C, Montero-Ojeda M, Bernardoni A, Anderson BE, Parra O. Human ehrlichiosis: report of the 1st case in Venezuela [in Spanish]. Invest Clin. 1996;37:35–49. 3. Gongora-Biachi RA, Zavala-Velasquez J, Castro-Sansores C, Gonzalez-Martinez P. First case of human ehrl...

Ehrlichia chaffeensis has type 1 and 4 secretion systems (T1SS and T4SS), but the substrates have not been identified. Potential substrates include secreted tandem repeat protein (TRP) 47, TRP120, and TRP32, and the ankyrin repeat protein, Ank200, that are involved in molecular host-pathogen interactions including DNA binding and a network of protein-protein interactions with host targets assoc...

BACKGROUND As there is little data on vector-borne diseases of cats in the Caribbean region and even around the world, we tested feral cats from St Kitts by PCR to detect infections with Babesia, Ehrlichia and spotted fever group Rickettsia (SFGR) and surveyed them for antibodies to Rickettsia rickettsii and Ehrlichia canis. RESULTS Whole blood was collected from apparently healthy feral cats...

Ehrlichia ewingii, a tick-transmitted rickettsia previously known only as a canine pathogen, was recently recognized as a human pathogen. E. ewingii has yet to be cultivated, and there is no serologic test available to diagnose E. ewingii infection. Previously, a fragment (505 bp) of a single E. ewingii gene homologous to 1 of 22 genes encoding Ehrlichia chaffeensis immunodominant major outer m...

BACKGROUND Our study aimed to assess the presence of different pathogens in ticks collected in two regions in Côte d'Ivoire. METHODOLOGY/PRINCIPAL FINDINGS Real-time PCR and standard PCR assays coupled to sequencing were used. Three hundred and seventy eight (378) ticks (170 Amblyomma variegatum, 161 Rhipicepalus microplus, 3 Rhipicephalus senegalensis, 27 Hyalomma truncatum, 16 Hyalomma marg...

Ehrlichia chaffeensis is an obligate, intracellular bacterium, transmitted by the tick Amblyomma americanum, and is the causative agent of human monocytic ehrlichiosis infections. We previously demonstrated that E. chaffeensis is capable of growing in Drosophila S2 cells. Therefore, we tested the hypothesis that E. chaffeensis can infect adult Drosophila melanogaster. Adult Drosophila organisms...

Human ehrlichiosis is a newly recognized rickettsial disease, first described in 1986 (5) in the United States. The first European case of ehrlichiosis, diagnosed on a serological and clinical basis, was reported in Portugal in 1991 (7). Furthermore, serological surveys recently conducted in Switzerland and the United Kingdom have shown the presence of antibodies to Ehrlichia phagocytophila in ...