Detection of Anaplasma phagocytophilum in ixodid ticks from equine-inhabited sites in the Southeastern United States.

Anaplasma phagocytophilum is a vector-borne, obligate intracellular bacterium that invades the neutrophils and eosinophils of infected individuals, causing granulocytic anaplasmosis. Equine cases have previously been reported in the United States from California, Florida, and Connecticut, but limited surveillance studies in the Southeast have been conducted. The objective of this study was to determine A.

Hard tick calreticulin (CRT) gene coding regions have only one intron with conserved positions and variable sizes.

Calreticulin (CRT) is a unique eukaryotic gene. The CRT gene product, calreticulin, was first identified as a calcium binding protein in 1974, but further investigations have indicated that CRT protein performs many functions in cells, including involvement in evading the host's immune system by parasites. Many studies of CRT have been published since the molecule was first discovered; however, the CRT gene exon-intron structure is only known for a limited number of ectoparasite species.

Cloning and sequencing of putative calreticulin complementary DNAs from four hard tick species.

Calreticulin (CRT) is a calcium-binding protein and has many functions in eukaryotic cells. CRT is possibly involved in parasite host immune system evasion. To better understand the molecular basis of CRT in ticks, we cloned and sequenced 4 full-length complementary DNAs (cDNAs) from the hard tick species, Dermacentor variabilis, Haemaphysalis longicornis, Ixodes scapularis, and Rhipicephalus sanguineus, using the technique of rapid amplification of cDNA ends.

Cloning and sequencing of putative acetylcholinesterase cDNAs from the American dog tick, Dermacentor variabilis, and the brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae).

Two putative cDNAs of acetylcholinesterase (AChE), one from Dermacentor variabilis, and the other from Rhipicephalus sanguineus, were amplified and sequenced. The deduced amino acid sequences have high amino acid identities (between 70 and 94%) to known tick AChE sequences deposited in GenBank. Furthermore, these two AChEs also possess common features in their primary AChE structure such as catalytic active sites.

Molecular phylogenetic analyses indicate that the Ixodes ricinus complex is a paraphyletic group.

The Ixodes ricinus species complex is a group of ticks distributed in almost all geographic regions of the world. Lyme borreliosis spirochetes are primarily transmitted by tick species within this complex. It has been hypothesized that the Lyme vector ticks around the world are closely related and represent a monophyletic group.

Prevalence of the agent of human granulocytic ehrlichiosis in Ixodes scapularis (Acari: Ixodidae) in the coastal southeastern United States.

Human granulocytic ehrlichiosis (HGE) is an emerging tick-borne disease recently recognized in the United States. The blacklegged tick, Ixodes scapularis Say, is the principle vector in the eastern United States. The disease has been commonly reported in the northeastern and upper midwestern states; however, suitable vectors and reservoir hosts exist in the southeast.