Characterization of Stages of Hepatozoon americanum and of Parasitized Canine Host Cells (2005)
Cummings, C. A, Panciera, R. J, Kocan, K. M, Mathew, J. S, Ewing, S. A
American canine hepatozoonosis is caused by Hepatozoon americanum, a protozoan parasite, the definitive host of which is the tick, Amblyomma maculatum. Infection of the dog follows ingestion of ticks...
M. V. Reichard, A. A. Kocan, R. A. Van Den Bussche, R. W. Barker, J. H. Wyckoff III, S. A. Ewing
Sequence analysis of the ribosomal DNA second internal transcribed spacer (ITS 2) region in 2 spatially distinct populations of Amblyomma americanum (L.) revealed intraspecific variation. Nucleotide...
R. W. Barker, A. Alan Kocan, S. A. Ewing, R. P. Wettemann, Mark E. Payton
Parasitic life stages of Amblyomma maculatum Koch were collected from domestic cattle and several species of wild mammals during a 3.5-yr study (May 1998–October 2001) in north-central Oklahoma....
Persistence of Hepatozoon americanum (Apicomplexa: Adeleorina) in a Naturally Infected Dog (2003)
S. A. Ewing, R. J. Panciera, J. S. Mathew
To determine the persistence of Hepatozoon americanum in a naturally infected dog, skeletal muscle biopsies were performed at approximately 6-mo intervals over a period of 5.5 yr, and the samples...
Transmission of Hepatozoon americanum (Apicomplexa: Adeleorina) by Ixodids (Acari: Ixodidae) (2002)
S. A. Ewing, J. S. Mathew, R. J. Panciera
American canine hepatozoonosis (ACH) caused by Hepatozoon americanum Vincent-Johnson, Macintire, Lindsay, Lenz, Baneth, and Shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in...
Dawson , J. E, Paddock, C. D, Warner , C. K, Greer , P. W, Bartlett, J. H, Ewing, S. A, ...
In the United States, human ehrlichiosis is a complex of emerging tick-borne diseases caused by 3 distinct Ehrlichia species: Ehrlichia chaffeensis, Ehrlichia ewingii, and the human granulocytotropic...
Panciera, R. J, Mathew, J. S, Cummings, C. A, Duffy, J. C, Ewing, S. A, Kocan, A. A
American canine hepatozoonosis is caused by Hepatozoon americanum, a recently described species of apicomplexan protozoan parasite. An immunohistochemical procedure using a polyclonal antibody to...
Ocular Histopathology of Ehrlichial Infections in the Dog (2001)
Panciera, R. J, Ewing, S. A, Confer, A. W
Histologic examination of eyes and brains of 27 dogs experimentally infected with either Ehrlichia canis, E. ewingii, E. chaffeensis, or human granulocytic ehrlichia (HGE) was conducted in the course...
An indirect enzyme-linked immunosorbent assay for diagnosis of American canine hepatozoonosis (2001)
Mathew, J. S, Saliki, J. T, Ewing, S. A, Lehenbauer, T. W, Panciera, R. J, Malayer, J. R, ...
American canine hepatozoonosis (ACH), caused by Hepatozoon americanum, is an emerging tick-borne disease of dogs. An indirect enzyme-linked immunosorbent assay (ELISA) that should facilitate...
J. S. Mathew, R. A. Van Den Bussche, S. A. Ewing, J. R. Malayer, B. R. Latha, R. J. Panciera
To evaluate higher-level affinities of Hepatozoon species within Apicomplexa, we sequenced the 18S rRNA gene from 2 parasites (Hepatozoon americanum and Hepatozoon canis) of dogs and 1 (Hepatozoon...
Mathew, J. S, Ewing, S. A, Malayer, J. R, Fox, J. C, Kocan, K. M
Detection of Ehrlichia canis in acutely infected and convalescent dogs is important for effective treatment and control. However, accurate detection has been difficult to achieve, in part because...
Mathew, J. S, Ewing, S. A, Panciera, R. J, Kocan, K. M
Light microscopic observations of the sporogonic development of Hepatozoon americanum are described in its acarine host, Amblyomma maculatum. Laboratory-reared nymphal ticks were fed on 2 dogs...
Johnson, E. M, Ewing, S. A, Barker, R. W, Fox, J. C, Crow, D. W, Kocan, K. M
Four trials were conducted in which laboratory-reared Dermacentor variabilis nymphs were exposed to Ehrlichia canis by feeding on experimentally infected dogs as soon as classical morulae were...
Mathew, J. S, Ewing, S. A, Murphy, G. L, Kocan, K. M, Corstvet, R. E, Fox, J. C
A mixed-breed pup approximately 3 months old obtained in north central Oklahoma by the Laboratory Animal Resources Unit of Oklahoma State University presented with platelet inclusions. The dog...
Ge, N. L, Kocan, K. M, Ewing, S. A, Blouin, E. F, Edwards, W. L, Murphy, G. L, ...
A sensitive Anaplasma marginale-specific 409-base pair DNA probe was developed in a previous study for detection of A. marginale infection in experimentally infected cattle with a test that employed...
Mathew, J. S, Ewing, S. A, Barker , R. W, Fox, J. C, Dawson , J. E, Warner , C. K, ...
OBJECTIVES: To compare the transmissibility by the brown dog tick, Rhipicephalus sanguineus, of a recent isolate of Ehrlichia canis (Ebony) with that of another isolate (Oklahoma) that had been...
Morton, R. J, Panciera, R. J, Fulton, R. W, Frank, G. H, Ewing, S. A, Homer, J. T, ...
Administration of an N-lauroylsarcosine-derived outer membrane protein fraction of Pasteurella haemolytica A1 (SCI-1) induced a protective response in calves against intrathoracic challenge exposure...
Ewing, S. A, Dawson , J. E, Kocan, A. A, Barker, R. W, Warner , C. K, Panciera , R. J, ...
Ehrlichia chaffeensis Anderson, Dawson & Wilson, causative agent of human (predominantly monocytic) ehrlichiosis, was successfully transmitted experimentally by Amblyomma americanum (L.) to...
Blouin, E. F, Blankemeyer, J. T, Kocan, K. M, Ewing , S. A
The ionophore A23187 was used to facilitate release and continued development of Anaplasma marginale in short-term erythrocyte cultures. Addition of 10 microM A23187 to the cultures resulted in...
Development of Anaplasma marginale in salivary glands of male Dermacentor andersoni. (1993)
Kocan, K. M, Goff , W. L, Stiller , D., Edwards , W., Ewing, S. A, Claypool , P. L, ...
Development of the rickettsia, Anaplasma marginale, in salivary glands of male Dermacentor andersoni exposed as nymphs or adult ticks, was studied indirectly by inoculation of susceptible calves with...
Kocan, K. M, Goff , W. L, Stiller, D., Claypool , P. L, Edwards, W., Ewing, S. A, ...
The persistence of Anaplasma marginale Theiler in male Dermacentor andersoni Stiles ticks exposed to the organism as adults was studied as the ticks were successively transferred to five susceptible...
Kocan, K. M, Stiller, D., Goff , W. L, Claypool, P. L, Edwards, W., Ewing , S. A, ...
The development and transmission of Anaplasma marginale was studied in Dermacentor andersoni males. Laboratory-reared male D andersoni were allowed to feed for 7 days on a calf with ascending A...
Ewing, S. A, Harkess , J. R, Kocan, K. M, Barker, R. W, Fox , J. C, Tyler, R. D, ...
An ear tick, Otobius megnini (Duges) recovered from a child who had serologic evidence of ehrlichiosis, was examined for Ehrlichia species microscopically and by inoculation into a susceptible dog;...
Development and infectivity of Anaplasma marginale in Dermacentor andersoni nymphs. (1990)
Kocan, K. M, Yellin , T. N, Claypool, P. L, Barron, S. J, Ewing, S. A, Hair, J. A
The development of Anaplasma marginale was studied in Dermacentor andersoni nymphs after they had fed on a calf with ascending Anaplasma infection. Gut tissues were collected on day 4 of tick...
Kocan, K. M, Stich, R. W, Claypool, P. L, Ewing, S. A, Hair, J. A, Barron, S. J
The development of Anaplasma marginale in midgut epithelial cells was studied in feeding, transmitting adult Dermacentor andersoni ticks. Laboratory-reared ticks experimentally infected as nymphs...
Current research on the development of anaplasma marginale in a tick vector, dermacentor spp. (1990)
Kocan, K. M, Goff, W. L, Stiller, D., Ewing, S. A, Barron, S. J, Hair, J. A, ...
Stiller, D., Kocan, K. M, Edwards, W., Ewing, S. A, Barron, J. A
Salivary glands from males of 3 Dermacentor species (D andersoni, D variabilis and D occidentalis) that were infected with either the Virginia or Idaho isolate of Anaplasma marginale as nymphs or...
Stich, R. W, Kocan, K. M, Palmer , G. H, Ewing, S. A, Hair, J. A, Barron, S. J
Transstadial and transovarial transmission of Anaplasma marginale by Dermacentor variabilis were attempted with with ticks exposed to the organism once by feeding as larvae or nymphs, and twice by...
A review of the developmental cycle of anaplasma marginale in dermacentor spp. ticks (1989)
Kocan, K. M, Stiller, D., Goff, W. L, Edwards, W., Wickwire, K. B, Stich, W., ...
A review of transmission studies of anaplasma marginale in dermacentor spp. ticks (1989)
Kocan, K. M, Stich, R. W, Edwards, W., Wickwire, K. B, Logan, T. M, Ewing, S. A, ...
Vectors of canine ehrlichiosis: impact on zoonosis (1989)
Ewing, S. A, Barker, R. W, Johnson, E. M, Harkess, J. R, Kocan, K. M, Fox, J. C, ...
Ichthyophthirius (Ciliophora): population studies suggest reproduction in host epithelium. (1988)
Ewing, M. S, Ewing, S. A, Kocan, K. M
Evidence that Ichthyophthirius multifiliis trophonts may reproduce within the epithelium of the host was obtained from experimental infections of channel catfish. Mean number of parasites...
Kocan, K. M, Wickwire , K. B, Ewing , S. A, Hair , J. A, Barron, S. J
On each day of feeding on susceptible calves, salivary glands obtained from groups of adult ticks that transmitted Anaplasma marginale were examined for A marginale colonies by use of light...
Persistence of colonies of Anaplasma marginale in overwintering Dermacentor variabilis. (1987)
Logan, T. M, Kocan, K. M, Edwards, W., Hair , J. A, Claypool , P. L, Ewing, S. A
Dermacentor variabilis were infected as nymphs with Anaplasma marginale by allowing the ticks to feed on a single infected donor calf. Two weeks after molting to the adult stage, the ticks were...
Infectivity of three Anaplasma marginale isolates for Dermacentor andersoni. (1987)
Wickwire, K. B, Kocan, K. M, Barron, S. J, Ewing , S. A, Smith, R. D, Hair , J. A
Three isolates of Anaplasma marginale--Virginia (VAM), Illinois (IAM), and Florida (FAM)--were compared for infectivity for Dermacentor andersoni. The isolates were selected, in part, because of a...
Kocan, K. M, Holbert , D., Edwards, W., Ewing, S. A, Barron , S. J, Hair, J. A
Colonies of Anaplasma marginale in midgut epithelial cells of experimentally infected Dermacentor andersoni were studied in adult ticks 1, 3, and 6 months old. Longevity of the parasite in ticks was...
Percutaneous infection of nymphal Dermacentor andersoni with Anaplasma marginale. (1986)
Kocan, K. M, Wickwire , K. B, Hair , J. A, Ewing, S. A, Barron, S. J
Newly replete nymphal Dermacentor andersoni (principals) were percutaneously exposed to Anaplasma marginale by injection of either intact or lysed infected bovine erythrocytes. Control nymphs were...
Transmission of Anaplasma marginale by adult Dermacentor andersoni during feeding on calves. (1985)
Kocan, K. M, Barron, S. J, Ewing , S. A, Hair , J. A
Laboratory-reared Dermacentor andersoni ticks experimentally infected as nymphs with Anaplasma marginale were allowed to feed as adults from 1 to 9 days on susceptible, splenectomized calves to...
Ichthyophthirius multifiliis (Ciliophora) invasion of gill epithelium. (1985)
Ewing, M. S, Kocan, K. M, Ewing, S. A
The sequence of morphological events associated with I. multifiliis invasion of Ictalurus punctatus gill epithelium began in the theront with differentiation of secretory mucocysts and the...
Kocan, K. M, Ewing , S. A, Hair , J. A, Barron, S. J
Dermacentor andersoni nymphs were placed in stockinettes and allowed to feed on a splenectomized calf with experimentally induced anaplasmosis when the parasitemia was 3%-5%. Nymphs were selected on...
Morphology of colonies of Anaplasma marginale in nymphal Dermacentor andersoni. (1984)
Kocan, K. M, Yellin, T. N, Ewing, S. A, Hair, J. A, Barron, S. J
Colonies of A. marginale were studied in midgut epithelial cells of nymphal D. andersoni infected by feeding on splenectomized calves with anaplasmosis. Colonies of A. marginale were not observed in...
Demonstration of colonies of Anaplasma marginale in the midgut of Rhipicephalus simus. (1983)
Potgieter, F. T, Kocan, K. M, McNew, R. W, Ewing , S. A
Rhipicephalus simus nymphs were allowed to feed on a cow experimentally infected with the BW-strain of Anaplasma marginale from Republic of South Africa, and they were studied as adults. Colonies...
Development of colonies of Anaplasma marginale in the gut of incubated Dermacentor andersoni. (1983)
Kocan, K. M, Holbert , D., Ewing , S. A, Hair, J. A, Barron , S. J
Kocan, K. M, Oberst, R. D, Ewing, S. A, Hair , J. A, Barron , S. J
Hemolymph was collected from adult Dermacentor andersoni Stiles that had been infected with Anaplasma marginale Theiler as nymphs. Before hemolymph was collected, the adult ticks were either...
Kocan, K. M, Holbert , D., Ewing, S. A, Hair, J. A, Barron, S. J
Four splenectomized dairy calves were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source (donor) for laboratory-reared Dermacentor andersoni Stiles...
Ichthyophthirius multifiliis: Morphology of the Cyst Wall (1983)
Ewing, M. S, Kocan, Katherine M., Ewing, S. A
The structure of the cyst wall of the free-living encysted stage of Ichthyophthirius multifiliis was studied by scanning and transmission electron microscopy. The wall consists of a relatively...
Staats, J. J, Kocan, K. M, Hair , J. A, Ewing, S. A
Colonies of Anaplasma marginale in midgut epithelial cells of adult ticks that had been infected as nymphs were specifically labeled, using the unlabeled antibody peroxidase-antiperoxidase method of...
Kocan, K. M, Ewing , S. A, Holbert , D., Hair , J. A
Colonies of Anaplasma marginale Theiler were studied in midgut epithelial cells of adult Dermacentor andersoni Stiles that were infected as nymphs. Colonies were categorized by light microscopy into...
Kocan, K. M, Barron, S. J, Holbert , D., Ewing, S. A, Hair , J. A
Three splenectomized dairy calves were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles nymphs....
Oberst, R. D, Kocan, K. M, Hair , J. A, Ewing, S. A
Colonies of Anaplasma marginale Theiler were studied in midgut epithelial cells of adult Dermacentor andersoni Stiles that were infected as nymphs. The colonies were demonstrated in plastic sections...
Kocan, K. M, Hair , J. A, Ewing , S. A, Stratton , L. G
Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles and D variabilis (Say) nymphs....
Kocan, K. M, Hair , J. A, Ewing, S. A
Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles and D variabilis (Say) nymphs....
Kocan, K. M, Hsu, K. C, Hair, J. A, Ewing, S. A
Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor variabilis (Say) nymphs. Transstadial transmission of...
Stich, Roger W., Rikihisa, Yasuko, Ewing, S. A., Needham, Glen R., Grover, Debra L., Jittapalapong, Sathaporn
Detection of vector-borne pathogens is necessary for investigation of their association with vertebrate and invertebrate hosts. The ability to detect Ehrlichia spp. within individual experimentally...
American Canine Hepatozoonosis
American canine hepatozoonosis (ACH) is a tick-borne disease that is spreading in the southeastern and south-central United States. Characterized by marked leukocytosis and periosteal bone...
Rikihisa, Y, Ewing, S A, Fox, J C
Ehrlichia chaffeensis, E. canis, and E. ewingii are genetically closely related, as determined by 16S rRNA gene base sequence comparison, but they exhibit biologic differences. E. chaffeensis is the...
Analyses of Ehrlichia canis and a canine granulocytic Ehrlichia infection.
Rikihisa, Y, Ewing, S A, Fox, J C, Siregar, A G, Pasaribu, F H, Malole, M B
Ehrlichia canis and canine granulocytic Ehrlichia sp. (CGE) infect canine monocytes and granulocytes, respectively. E. canis has been cultured in vitro and used to develop an immunofluorescence...
Epidemiologic and clinical characteristics of persons with serologic evidence of E. canis infection.
Rohrbach, B W, Harkess, J R, Ewing, S A, Kudlac, J, McKee, G L, Istre, G R
The results of a serosurvey of Oklahomans for the presence of antibody to Ehrlichia canis is reported. Paired serum specimens, from patients lacking the serologic criteria for diagnosis of Rocky...
Stich, Roger W., Rikihisa, Yasuko, Ewing, S. A., Needham, Glen R., Grover, Debra L., Jittapalapong, Sathaporn
Detection of vector-borne pathogens is necessary for investigation of their association with vertebrate and invertebrate hosts. The ability to detect Ehrlichia spp. within individual experimentally...