Heartwater, a tick-borne disease of domestic and wild ruminants, is caused by the intracellular rickettsia Ehrlichia ruminantium (previously known as Cowdria ruminantium). It is a major constraint to livestock production throughout subSaharan Africa, and it threatens to invade the Americas, yet there is no immediate prospect of an effective vaccine. A shotgun genome sequencing project was undertaken in the expectation that access to the complete protein coding repertoire of the organism will facilitate the search for vaccine candidate genes. We report here the complete 1,516,355-bp sequence of the type strain, the stock derived from the South African Welgevonden isolate. Only 62% of the genome is predicted to be coding sequence, encoding 888 proteins and 41 stable RNA species. The most striking feature is the large number of tandemly repeated and duplicated sequences, some of continuously variable copy number, which contributes to the low proportion of coding sequence. These repeats have mediated numerous translocation and inversion events that have resulted in the duplication and truncation of some genes and have also given rise to new genes. There are 32 predicted pseudogenes, most of which are truncated fragments of genes associated with repeats. Rather then being the result of the reductive evolution seen in other intracellular bacteria, these pseudogenes appear to be the product of ongoing sequence duplication events.gene duplication ͉ bacterial genome ͉ molecular sequence data ͉ intracellular adaptation E hrlichia ruminantium (previously known as Cowdria ruminantium) is an obligate intracellular bacterium in the order Rickettsiales. Species in this order cause serious diseases in man and domestic animals throughout the world. E. ruminantium is transmitted by ticks of the genus Amblyomma and causes heartwater, a fatal and economically important disease of wild and domestic ruminants. The disease occurs throughout subSaharan Africa and on several Caribbean islands, from which it threatens to invade the Americas (1), but the existing immunization procedures are rudimentary and relatively ineffective (2). E. ruminantium is a fragile bacterium with exacting culture requirements in eukaryotic cell lines; genetic manipulation has not been attempted, and little is known about its mechanisms of virulence or pathogenesis. Heartwater affects all domestic ruminants, and 80-95% of naïve animals die within 3 weeks, but those that recover have a T cell-mediated immunity to subsequent homologous challenge (3). In the absence of any directed strategy to identify T cell-stimulatory proteins we sequenced the E. ruminantium genome in the expectation that access to the complete protein-coding repertoire of the organism would facilitate the search for vaccine candidate genes.

HighlightsA reverse line blot assay was used to estimate tick-borne haemoparasite prevalence in an intensively studied cohort of indigenous cattle in western Kenya.There were high prevalences of Theileria mutans (71.6%), T. velifera (62.8%), Anaplasma sp. Omatjenne (42.7%), A. bovis (39.9%), Theileria sp. (sable) (32.7%), T. parva (12.9%) and T. taurotragi (8.5%), with minor occurrences of eight other haemoparasites.The most prevalent haemoparasites were mostly present as coinfections, with strong associations between several of the Theileria parasites, in particular T. velifera with Theileria sp. sable and T. mutans, and T. parva with T. taurotragi.Comparison of RLB and serological results indicated that indigenous cattle seem capable of clearing infections of three pathogenic parasites (T. parva, A. marginale and B. bigemina), whereas infections with the mostly benign T. mutans are more persistent.

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Cerebrovascular disease is one of the leading causes of death and the cause of long-term adult disability. An important characteristic of thromboembolic ischemic stroke is a prothrombotic or hypercoagulable state and altered fibrin clot structure, whereas a resistance to fibrinolysis is also present. An expansive fibrin network is created when adding thrombin, and in stroke, the network appears thickened, netted and matted, compared with that of healthy individuals. Although this is clearly visible in micrographs of patients, there is a need to quantify the changes. The current study, therefore, investigates fibrin fiber diameters in stroke patients and compares it to healthy individuals. The fiber diameters were measured in nanometres, with University of Texas Health Science Center at San Antonio (UTHSCSA) Image Tool. A total of 100 measurements were done for each of the 12 patients in the healthy control group, and the same number of measurements was done for 12 stroke patients. These measurements were statistically analysed with NCSS 2007, using a significance level of 0.05. Normality was assessed with the Shapiro-Wilk W test and the thickest and thinnest fiber of each individual in the two groups was quantified and differences between groups were assessed with the Student's t-test. Results showed that there is a statistical difference in fibrin fiber thickness during thromboembolic ischemic stroke. We conclude that the changed coagulation and hemostasis, typically associated with stroke, causes a statistically relevant change in fibrin thickness, and that this netted and matted network is more resistant to lyses.

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We have reported previously that a recombinant DNA vaccine consisting of four

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