Equine Granulocytic Anaplasmosis (EGA) is an acute tick-borne infection caused by Anaplasma phagocytophilum. The bacterium can infect various animal species and humans. Persistence of infection is documented in ruminants and is shown experimentally in dogs, but it is unknown whether it occurs in horses or if EGA induces longer-term clinical changes in horses. This thesis includes results and an...

Human granulocytic anaplasmosis (HGA) and Lyme borreliosis (LB) are tick-borne and emerging infectious diseases caused by the Anaplasma phagocytophilum and Borrelia burgdorferi species. In Europe, including Slovakia, the principal vector of both pathogens is the common tick - Ixodes ricinus, in which double infections with these pathogens have been reported. The aim of our study was evidence of...

Anaplasma phagocytophilum is the etiologic agent of human granulocytic anaplasmosis (HGA), one of the major tick-borne zoonoses in the United States. The surface of A. phagocytophilum plays a crucial role in subverting the hostile host cell environment. However, except for the P44/Msp2 outer membrane protein family, the surface components of A. phagocytophilum are largely unknown. To identify t...

Human granulocytic anaplasmosis, caused by the tick-transmitted Anaplasma phagocytophilum, is not controlled by innate immunity, and induces a proinflammatory disease state with innate immune cell activation. In A. phagocytophilum murine infection models, hepatic injury occurs with production of IFNγ thought to be derived from NK, NKT cells, and CD8 T lymphocytes. Specific A. phagocytophilum li...

Anaplasma phagocytophilum is a zoonotic obligate intracellular bacterium known to be transmitted by ticks belonging to the Ixodes persulcatus complex. This bacterium can infect several mammalian species, and is known to cause diseases with variable symptoms in many domestic animals. Specifically, it is the causative agent of tick-borne fever (TBF), a disease of important economic impact in Euro...

Anaplasma phagocytophilum is an intracellular tick-borne rickettsial pathogen, which causes granulocytic anaplasmosis in various species of livestock and companion animals and also in humans. Previously A. phagocytophilum has been isolated and propagated in cell lines derived from the tick Ixodes scapularis and in the human promyelocytic cell line HL60. In this study we used the Ixodes ricinus-...

Anaplasma phagocytophilum, the agent of human anaplasmosis, persists in ticks and mammals. We show that A. phagocytophilum induces the phosphorylation of actin in an Ixodes ricinus tick cell line and Ixodes scapularis ticks, to alter the ratio of monomeric/filamentous (G/F) actin. A. phagocytophilum-induced actin phosphorylation was dependent on Ixodes p21-activated kinase (IPAK1)-mediated sign...

SNAP® 4Dx® (IDEXX Laboratories, Westbrook, ME) is a commercially available in-office test kit for the simultaneous detection of Dirofilaria immitis antigen and antibodies to Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia canis in blood, plasma, or serum of dogs. The test kit is an enzyme-linked immunosorbent assay that uses the synthetic peptide C6 derived from the IR6 region wi...

Human granulocytic ehrlichiosis (HGE) is an emerging tick-borne infectious disease caused by Anaplasma phagocytophilum. Clinical features include a flu-like illness that usually resolves within 1 week. More serious infection may occur that requires hospital admission or culminates in death. Doxycycline is the treatment of choice for HGE but may cause permanent staining of teeth in children youn...

Anaplasmosis is an emerging infectious disease caused by infection with the bacterium Anaplasma phagocytophilum. In the eastern United States, A. phagocytophilum is transmitted to hosts through the bite of the blacklegged tick, Ixodes scapularis. We determined the realized reservoir competence of 14 species of common vertebrate hosts for ticks by establishing the probability that each species t...