The development of Cowdria ruminantium in neutrophils.

The sequential development of C. ruminantium (Kwanyanga and Kümm isolates) was followed in caprine leukocyte cultures by light microscopy, direct immunofluorescent microscopy (DFA), indirect immunoflourescent microscopy (IFA) and transmission electron microscopy (TEM). During the febrile response, one to several small cocci, large ring forms or rods were observed in neutrophils in blood smears and cytopreparations of neutrophil fractions using Diff Quik stain, Giemsa stain, DFA and TEM. One to several C. ruminantium colonies were seen in up to 35% of neutrophils maintained in vitro for 18 h to 5 days. The organisms were located in neutrophil phagosomes by TEM and were enveloped by two trilamellar unit membranes. Initially, C. ruminantium was tightly enclosed within phagosomes. At 20 h of incubation, organisms were frequently observed undergoing binary fission within enlarged phagosomal vacuoles. At later time periods, neutrophils harboured fully formed colonies (morula) containing numerous organisms. An occasional C. ruminantium-infected macrophage (Kümm isolate), and an occasional infected eosinophil (Kümm and Kwanyanga isolate) were found.

[1]  Y. Rikihisa,et al.  Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever , 1985, Infection and immunity.

[2]  N. Barré,et al.  Setting up a method for surveying the distribution of cowdriosis (heartwater) in the Caribbean , 1984 .

[3]  G. Uilenberg.  Heartwater (Cowdria ruminantium infection): current status. , 1983, Advances in veterinary science and comparative medicine.

[4]  H. D. Liggitt.  Characterization of short- and long-term cultured goat peripheral blood monocytes. , 1983, American journal of veterinary research.

[5]  A. H. Dardiri,et al.  Observation of Rickettsia ruminantium in leukocytic cell cultures from heartwater-infected goats, sheep, and cattle. , 1983, American journal of veterinary research.

[6]  G. Uilenberg.  Experimental transmission of Cowdria ruminantium by the Gulf coast tick Amblyomma maculatum: danger of introducing heartwater and benign African theileriasis onto the American mainland. , 1982, American journal of veterinary research.

[7]  A. Perel,et al.  Leukocytes Are Required for Increased Lung Microvascular Permeability after Microembolization in Sheep , 1981, Circulation research.

[8]  A. V. van Winkelhoff,et al.  Cowdria ruminantium (Rickettsiales) in primary goat kidney cell cultures. , 1980, Research in veterinary science.

[9]  M. Lawman,et al.  The establishment of continuous macrophage cell lines from peripheal blood monocytes. , 1980, Immunology.

[10]  D. R. Boogs.  Physiology of neutrophil proliferation, maturation and circulation. , 1975, Clinics in haematology.

[11]  M. Andreasen.  Multiplication of Cowdria ruminantium in monolayer of tick cells. , 2009, Acta pathologica et microbiologica Scandinavica. Section B: Microbiology and immunology.

[12]  E. Cronkite,et al.  The intravascular survival of neutrophils labeled in vivo. , 1974, Blood.

[13]  G. Carlson,et al.  Isolation of leukocytes from bovine peripheral blood. , 1973, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[14]  A. R. Smith,et al.  Tropical canine pancytopenia: in vitro cultivation of the causative agent--Ehrlichia canis. , 1971, American journal of veterinary research.

[15]  S. Bencosme,et al.  Fast method for processing biologic material for electron microscopy. , 1970, Laboratory investigation; a journal of technical methods and pathology.

[16]  J. D. du Plessis.  Pathogenesis of heartwater. I. Cowdria ruminantium in the lymph nodes of domestic ruminants. , 1970, The Onderstepoort journal of veterinary research.

[17]  D. Gribble.  Equine ehrlichiosis. , 1969, Journal of the American Veterinary Medical Association.

[18]  M. Karnovsky,et al.  A formaldehyde-glutaraldehyde fixative of high osmolality for use in electron-microscopy , 1965 .

[19]  K. A. Topleninova.  The application of the indirect fluorescent antibody method to detect rabies virus. , 1961, Problems of virology.

[20]  W. Hess,et al.  The use of leukocyte cultures for diagnosing African swine fever (ASF). , 1960 .

[21]  R. Alexander.  Heartwater.-The present State of our Knowledge of the Disease. , 1931 .