Hassan department of parasitology faculty of veterinary medicine university of khartoum cosupervisor. Small, gram negative, pleomorphic coccus, and obligate. The rickettsial bacterium ehrlichia ruminantium is the causative pathogen of heartwater in ruminants. Ehrlichia ruminantium is an obligately intracellular proteobacterium which causes a disease known as heartwater or cowdriosis in some wild.
Ehrlichia ruminantium, the causative agent of heartwater, is transmitted by amblyomma spp. The disease is caused by ehrlichia formerly cowdria ruminantium, a rickettsial pathogen in the genogroup which includes the monocytotropic species ehrlichia canis and ehrlichia chaffeensis 3, the agents, respectively, of tropical canine pancytopenia, which has a pantropical distribution, and human monocytic ehrlichiosis, which has been. It causes high mortalities in sheep, goats, and cattle and is of major economic importance to livestock production and development in subsaharan africa and on several caribbean islands 28, 36, 44. Ehrlichia ruminantium infects rhipicephalus microplus in west africa. We have previously reported that the pcs20 pcr detection assay for cowdria ruminantium, the causative agent of heartwater disease of ruminants, is more sensitive than xenodiagnosis and the pcs20 dna probe for the detection of infection in the vector amblyomma ticks. Mortality rates among susceptible hosts can reach 90%, and the design of any potential vaccine is complicated by the fact that field isolates differ in immunogenicity. Article pdf available in annals of the new york academy of sciences 10638. Cowdria ruminantium pdf ehrlichia ruminantium formerly cowdria ruminantium. Summary panola mountain ehrlichia pme is an emerging ehrlichia sp. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks. Ehrlichia ruminantium and panola mountain ehrlichia minantium, the causative agent of heartwater is primarily a disease of ruminants cattle, sheep and goats causing great economic impact in south africa and the caribbean transmitted by a variety of amblyomma spp ticks in all their developmental stages. Heartwater results from infection by the bacterium ehrlichia formerly cowdria ruminantium, a small, gram negative, pleomorphic coccus in the family anaplasmataceae and order rickettsiales. Molecular detection and characterization of ehrlichia ruminantium. Previous studies have shown that early stages of development may be critical for ehrlichia pathogenicity.
Heartwater is a noncontagious, tickborne disease caused by ehrlichia ruminantium, an intracellular parasite in the order rickettsiales. Nested pcr for detection and genotyping of ehrlichia. Populationbased evaluation of the ehrlichia ruminantium map 1b. To gain insights into the biology of intracellular er, we determined the genome. Heartwater is a tickborne rickettsial disease of domestic and wild ruminants. Under natural conditions, e ruminantium is transmitted by amblyomma ticks. Based on the sequence homology of all known genes, pme is closely related to ehrlichia ruminantium e. Summary heartwater is a notifiable disease that is listed by the world organisation for animal health. Point seroprevalence survey of ehrlichia ruminantium. This organism is an obligate intracellular parasite. Heartwater is a ticktransmitted disease of ruminants caused by ehrlichia ruminantium. View enhanced pdf access article on wiley online library html view download pdf for offline viewing. Ehrlichia ruminantium is an obligate intracellular bacterium that causes heartwater, a fatal tickborne disease of livestock, with high economical impact in subsaharan africa and some islands in the indian ocean and the caribbean. Diagnosis of ehrlichia ruminantium in ruminants in central sudan using polymerase chain reaction.
Efficient highthroughput molecular method to detect. Pdf diagnosis of ehrlichia ruminantium in ruminants in. It occurs in colonies or morulae with a predilection for the vascular endothelium and. Heartwater also known as cowdriosis, nintas, and ehrlichiosis is a tickborne rickettsial disease of domestic and wild ruminants. Herein, we used mass spectrometrybased assays to study protein phosphorylation and glycosylation in ehrlichia ruminantium gardel virulent ergvir and attenuated ergatt variants and, how they can modulate ehrlichia. The immunodominant 32kilodalton protein of cowdria ruminantium is conserved within the genus ehrlichia. A polyclonal competitive enzymelinked immunosorbent assay pcelisa is described for detection of antibodies to ehrlichia cowdria ruminantium by using a soluble extract of endothelial cell culturederived e. Heartwater imposes a high economic cost to livestock industries since it induces high mortality up to 80 % in susceptible animals, especially goats and sheep. Ehrlichia ruminantium formerly cowdria ruminantium is a tickborne rickettsial pathogen that infects cattle, causing heartwater or cowdriosis. Pdf detection of ehrlichia ruminantium infection in cattle in. Here, we report the draft genome sequences of three strains of e.
Ehrlichia ruminantium in amblyomma variegatum and domestic. Effect of dimethyl sulfoxide in the treatment of sheep. Ehrlichia ruminantium infects rhipicephalus microplus in. Ehrlichia ruminantium er, the causative agent of heartwater on ruminants, is an obligate intracellular bacterium transmitted by ticks of the genus amblyomma.
Recognition of the threat of ehrlichia ruminantium infection in domestic and wild ruminants in the continental united states. In order to investigate the extent of genetic diversity among ehrlichia ruminantium strains in cameroon, a partial fragment 800 bp of the e. New molecular high throughput methods for ehrlichia ruminantium. Cowdria ruminantium,4 the causative organism of heartwater, has recently been reclassified asehrlichia ruminantiumbased on genetic analysis as well as. Ehrlichia ruminantium, transmitted by ticks of the genus amblyomma, causes heartwater in. Here, we further assessed the reliability of the pcr assay and applied it to field ticks. The organism is transmitted by ticks of the genus amblyomma, and it is of serious economic importance wherever the natural vectors occur, an area which includes all of. Ehrlichia ruminantium infection heartwater is a major constraint that impacts negatively on the cattle industry development in subsaharan africa and so far, little is known of the presence of heartwater in cattle in cameroon. This article is within the scope of wikiproject veterinary medicine, a collaborative effort to improve the coverage of veterinary medicine on wikipedia.
Unraveling which proteins and posttranslational modifications ptms affect bacterial pathogenesis and physiology in diverse environments is a tough challenge. The rickettsial bacterium ehrlichia ruminantium is the causative agent of heartwater in. Molecular epidemiology of heartwater ehrlichia ruminantium. Amblyomma variegatum ticks, which are found in the caribbean and subsaharan africa, except in certain areas of southern africa, are major vectors of e. Multilocus sequence typing of ehrlichia ruminantium. Heartwater the center for food security and public health. However, to date, little data has been published regarding the. Wed like to understand how you use our websites in order to improve them. The obligate intracellular pathogenic bacterium, ehrlichia ruminantium, is the causal agent of heartwater, a fatal disease in ruminants transmitted by amblyomma ticks. For goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of. Ehrlichia canis, ehrlichia ruminantium and a recently described species, ehrlichia muris eauclairensis are also occasionally infect humans allsopp et al. Ticks and tickborne diseases tbds continue to pose an insidious and everpresent threat to livestock and livelihoods across the globe. Using the map1b enzymelinked immunosorbent assay, we tested 1,318 serum samples collected from sheep and goats at 28 sites in the five divisions of the gambia to determine the ehrlichia ruminantium seroprevalence rates and to assess the risk for heartwater. Novel ehrlichia and hepatozoon agents infecting the crab.
Ehrlichia ruminantium an overview sciencedirect topics. Ehrlichia ruminantium is an obligate intracellular bacterium that causes heartwater, an infectious, virulent, transmissible but noncontagious disease of ruminants. Objectiveto evaluate the clinical response of sheep experimentally infected with ehrlichia ruminantium to treatment with dimethyl sulfoxide dmso animals32 merino crossbred sheep procedure16 sheep were infected with e ruminantium. It is caused by ehrlichia ruminantium, an obligately intracellular gramnegative bacterium in the order rickettsiales and the family anaplasmataceae. Pdf ehrlichia ruminantium, an emerging human pathogen a. It is one of four most important tickborne cattle diseases in tropical regions babesioses, theilerioses, anaplasmosis, and heartwater. Abstract ehrlichia ruminantium is an obligately intracellular proteobacterium which causes a disease known as heartwater or cowdriosis in some wild, and all domestic, ruminants. Ehrlichia ruminantium, the tickborne causative agent of heartwater in domestic and wild ruminants, is widespread throughout subsaharan africa, in madagascar, and on some islands in the caribbean. The attenuated strains have improved capacity for growth in vitro, whereas they induced limited clinical signs in vivo and conferred strong.
Genetic diversity of ehrlichia ruminantium in amblyomma. The causative organism is an obligate intracellular parasite, previously known as cowdria ruminantium. Ehrlichia cowdria ruminantium is a gramnegative, intracellular rickettsial organism in the order of rickettsiales. Ehrlichia ruminantium major antigenic protein gene map1. Draft genome sequences of three strains of ehrlichia. Development of a polyclonal competitive enzymelinked. Pdf on jan 1, 2006, m louw and others published ehrlichia ruminantium, an emerging human. So far, three strains have been attenuated by successive passages in mammalian cells. Ehrlichia cowdria ruminantium is a gramnegative, intracellular rickettsial organism in the. Recognition of the threat of ehrlichia ruminantium. Ehrlichia ruminantium, an obligatory intracellular rickettsia, is the causative agent of heartwater, a tickborne disease that circulates throughout subsaharan africa, the caribbean and indian ocean islands. Ehrlichia ruminantium formerly cowdria ruminantium is an obligately intracellular tickborne parasite that causes a cowdriosis, an acute and fatal infection of sheep, goats, and cattle. Ehrlichia ruminantium formerly cowdria ruminantium. Heartwater results from infection by the bacterium ehrlichia formerly cowdria ruminantium, a small.
The highly sensitive nested pcs20 polymerase chain reaction assay for ehrlichia ruminantium was negative on 506 amblyomma variegatum from caribbean islands where clinical heartwater has not been reported, mainly the united states virgin islands 18, dominica 170, montserrat 5, nevis 34, st. Pdf genetic diversity of ehrlichia ruminantium strains. Global gene expression profiling of ehrlichia ruminantium. Start this article has been rated as startclass on the projects quality scale. These threehost ticks become infected during either the larval or nymphal. The disease is spread by bont ticks, which are members of the genus amblyomma. Ehrlichia ruminantium, the agent of cowdriosis transmitted by amblyomma ticks, presents an extensive genetic and antigenic diversity of key importance for vaccine formulation. Diversity of ehrlichia ruminantium major antigenic protein. Goodrich, in rebhuns diseases of dairy cattle third edition, 2018. Ehrlichia ruminantium is the causal agent of heartwater, a ruminant tropical. Understanding genetic diversity of ehrlichia ruminantium in host and vector populations is an important prerequisite to controlling heartwater by vaccination in traditional livestock systems in subsaharan africa. Ehrlichia ruminantium is the causative agent of heartwater, an important tickborne disease of livestock in africa and the caribbean that threatens the american mainland. Different vaccines with various efficacies have been produced against e. Ehrlichiosis information nc state veterinary medicine.
Ehrlichia ruminantium infection heartwater is a major constraint that impacts negatively on the. The disease is widespread in most of subsaharan africa and on several islands in the caribbean, where it is. Download to citation manager related articles found in. Molecular epidemiology of heartwater ehrlichia ruminantium infection in domestic ruminants in the sudan by mohammed sayed mohammed suliman bvsc university of nyala, 1999 mvsc university of khartoum, 2005 supervisor dr. The species cowdria ruminantium was placed in the genus ehrlichia as ehrlichia ruminantium with the existing species ehrlichia chaffeensis, ehrlichia ewingii, ehrlichia canis and ehrlichia muris. It is unable to survive outside of its host for more than a few hours and can only be. Heartwater cowdriosis is a tickborne disease of cattle, sheep, goats and some wild ruminants that is caused by a rickettsia, ehrlichia ruminantium, previously known as cowdria ruminantium. Two means of nested polymerase chain reaction pcr targeting were developed to conduct molecular epidemiology studies in the caribbean and africa. Detection of ehrlichia ruminantium infection in cattle in. Molecular evidence led to reclassification of several organisms in the order rickettsiales, and it is now classified as ehrlichia ruminantium. Its main vectors are amblyomma hebraeum ticks in southern africa and a.
Ehrlichia ruminantium, amblyomma variegatum, heartwater, caribbean, west indies. Two of the most significant tbds of cattle in africa are heartwater and babesioisis, caused by ehrlichia ruminantium and babesia bigemina respectively. Cowdria ruminantium,4 the causative organism of heartwater, has. Detection of the agent of heartwater, cowdria ruminantium.