Nineteen per cent and 32% of serologically positive sheep and goats in heartwater endemic areas of the Republic of South Africa were susceptible to challenge with, respectively, the Ball 3 and Welgevonden stocks of Cowdria ruminantium. There was good correlation between the results of the indirect fluorescent antibody test and immunity, since without exception all the seronegative animals react...

Early diagnosis of canine ehrlichiosis favors prompt institution of treatment and improves the prognosis for the animal, since this disease causes mortality among dogs. Studies have shown that determining the concentration of acute-phase proteins (APPs) may contribute towards early detection of disease and aid in predicting the prognosis. This study aimed to evaluate the APP profile in dogs exp...

Techniques for the rearing of Amblyomma species to be used in heartwater (Cowdria ruminantium) transmission experiments are discussed. These involve the breeding and maintenance of infected and non-infected strains of ticks. They include the feeding of ticks on sheep, rabbits, mice, tortoises and guinea fowl.

Heartwater is a tick borne disease that affects ruminants and wild animals in Africa south of the Sahara. It is caused by Ehrlichia ruminantium and transmitted by the tick Amblyomma hebraeum. The protocols currently used to detect heartwater take several days to complete. Here, we describe the development of a pCS20 quantitative real-time PCR TaqMan probe assay to detect E. ruminantium in lives...

Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, is transmitted by Amblyomma americanum ticks, which are most abundant in the southern United States. Because serologic evidence suggests that residents of Connecticut are exposed to E. chaffeensis, A. americanum ticks were collected in Connecticut and Rhode Island for PCR analysis to detect E. chaffeensis DNA. Eight of ...

A sensitive and reliable enzyme-linked immunosorbent assay for the detection of antibodies to Cowdria ruminantium in serum and C. ruminantium antigen in Amblyomma hebraeum nymphae is described. For the screening of antibodies, C. ruminantium from A. hebraeum nymphae, partially purified by wheat-germ lectin affinity chromatography, was used as antigen. To screen nymph populations, sera from eith...

After being passaged through 3 generations of Amblyomma hebraeum, an Ehrlichia-like agent isolated from an adult Hyalomma truncatum female became more pathogenic and elicited a disease in sheep indistinguishable from heartwater. Cross-immunity between this agent and several stocks of Cowdria ruminantium and high levels of antibody elicited by the agent against 2 stocks of C. ruminantium in the ...

Canine ehrlichiosis which becomes widespread worldwide is generated by a pathogen bacteria called Ehrlichia Canis. The prevalence of ehrlichiosis changes according to geographic regions in veterinary practice. The aim of this study was to determine the prevalence of the canine ehrlichiosis in Uşak, Turkey, together with clinical, hematological and biochemical signs. 100 dogs found in 6 differen...

The ultrastructure of the etiological agent of equine ehrlichiosis, Ehrlichia equi, was studied in equine peripheral leukocytes. The organisms occurred within membrane-lined cytoplasmic vacuoles of neutrophils and eosinophils. Ovoid, round, and rod-shaped profiles were observed. From 1 to 33 organisms were present in a thin-section profile of a cytoplasmic vacuole. Many cells contained multiple...