Anaplasma phagocytophilum - Molecular diagnosis (PCR)

 

Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) is classified in the genus Anaplasma, family Anaplasmataceae the order rickettsial organism. Anaplasma phagocytophilum is the newly assigned replacement of three species of bacteria granulocyte name: Ehrlichia phagocytophila, Ehrlichia equi and the agent of human granulocytic ehrlichiosis. Anaplasma phagocytophilum is a Gram - negative bacteria that can cause intracellular anaplasmosis in cattle and sheep and is also responsible for human granulocytic anaplasmosis zoonotic disease.

The life cycle of this microorganism involves intermediate host where mature, Ixodes persulcatus as generally ticks. One of the features of this organization is that infects and actively growing inside of neutrophils due to impaired function of the host cell. Specifically, alter the normal function of neutrophils such as adhesion to endothelial cells, transmigration, motility, degranulation, respiratory burst and phagocytosis. Moreover, it is able to survive in a host organism, apparently immune, by using a complex mechanism of antigenic variation. Because this bacteria invade neutrophils, has adapted and unique pathogenetic mechanism.

In humans this bacterium causes human granulocytic anaplasmosis, a disease whose symptoms associated include fever, headache, leukopenia, thrombocytopenia and mild liver damage. Anaplasma phagocytophilum transmission to humans can be potentially lethal.

In animals, Anaplasma phagocytophilum transmission through ticks, causes a multisystem disease whose symptoms are severe intense febrile reaction, anemia and leukopenia. This organism causes difficulty walking, which often can be confused with Lyme disease, other tick - borne disease. Morula generated inside neutrophils can be displayed inside the peripheral blood neutrophils and synovial fluid. Other signs and associated symptoms can include lethargy, ataxia, loss of appetite, and pain or weakness in the limbs. Because of the serious hematological disorders lasting several days and other adverse effects on the host immune functions, infected animals are more susceptible to other infections.

Recommended tests for diagnosis:

 

The diagnosis is based on microscopic identification of parasites in saguíneos smear immunosorbent assay (ELISA), or molecular diagnostic methods (PCR).

Tests in IVAMI:

 

    • Molecular diagnosis (PCR), to detect DNA of Anaplasma phagocytophilum.

Recommended sample:

 

      • Whole blood collected with EDTA (2 to 5 mL).

Preservation and shipment of sample:

 

      • Refrigerated (preferred) for less than 2 days.
      • Frozen: over 2 days.

 

Delivery term:

 

      • Molecular diagnosis (PCR): 24 to 48 hours.