Newly recognized Anaplasma sp. in erythrocytes from Gopher Tortoises (Gopherus polyphemus).

BACKGROUND: In 2015, a previously unrecognized intracytoplasmic erythrocytic inclusion was discovered in anemic wild-caught adult gopher tortoises (Gopherus polyphemus). Subsequently, molecular diagnostics revealed this inclusion to be a novel Anaplasma sp. OBJECTIVES: The goal of this study was to morphologically characterize these erythrocytic inclusions by light and transmission electron microscopy (TEM). METHODS: Blood samples were taken from two car-injured wild-caught gopher tortoises for the preparation of Wright-Giemsa stained smears and TEM specimens. CBC data were serially performed and morphologically examined during treatment periods. RESULTS: Studies revealed a moderate to severe anemia with moderate regeneration as indicated by polychromasia and the presence of immature erythroid precursors. In addition, on light microscopy, one to two variably-sized round basophilic stippled paracentral erythrocytic inclusions were present per cell in both animals and involved 10%-25% of erythrocytes. TEM identified the intraerythrocytic inclusions as discrete membrane-bound cytoplasmic vacuoles (morulae) containing membrane-bound bacterial subunits that were of variable size, shape, and electron density. Serial hematologic data indicated complete remission of the infection in response to a single long-term course of doxycycline. CONCLUSIONS: The presence of a regenerative anemia in gopher tortoises from Florida revealed a newly recognized bacterial species that has morphologic characteristics similar to members of the genus Anaplasma.

Identification of Anaplasma ovis appendage-associated protein (AAAP) for development of an indirect ELISA and its application.

BACKGROUND: Ovine anaplasmosis is a tick-borne disease that is caused by Anaplasma ovis in sheep and goats. The pathogen is widely distributed in tropical and subtropical regions of the world. At present, diagnosis of the disease mainly depends on microscopy or nucleic acid based molecular tests, although a few serological tests have been applied for the detection of A. ovis infection. RESULTS: Here we describe the identification of an A. ovis protein that is homologous to the A. marginale appendage-associated protein (AAAP). We expressed a recombinant fragment of this protein for the development of an indirect enzyme-linked immunosorbent assay (ELISA) for the detection of A. ovis. Anaplasma ovis-positive serum showed specific reactivity to recombinantly expressed AAAP (rAAAP), which was further confirmed by the rAAAP ELISA, which also demonstrated no cross-reactivity with sera from animals infected with A. bovis or other related pathogens in sheep and goats. Testing antibody kinetics of five experimentally infected sheep for 1 year demonstrated that the rAAAP ELISA is suitable for the detection of early and persistent infection of A. ovis infections. Investigation of 3138 field-collected serum samples from 54 regions in 23 provinces in China demonstrated that the seroprevalence varied from 9.4% to 65.3%, which is in agreement with previous reports of A. ovis infection. CONCLUSIONS: An A. ovis derived antigenic protein, AAAP, was identified and the antigenicity of the recombinant AAAP was confirmed. Using rAAAP an indirect ELISA assay was established, and the assay has been proven to be an alternative serological diagnostic tool for investigating the prevalence of ovine anaplasmosis of sheep and goats.

Human anaplasmosis presenting as atypical pneumonitis in France.

Human anaplasmosis is a febrile illness caused by Anaplasma phagocytophilum, an intracellular bacterium transmitted by Ixodes ticks in the United States and Europe. Although cough is reported in 30% of the American cases, interstitial pneumonitis has been noted only once. Of the 9 confirmed cases reported in Europe, 3 presented with atypical pneumonitis. A. phagocytophilum should be added to the list of agents responsible for interstitial pneumonitis, especially in areas where human anaplasmosis is endemic.