Immunisation of sheep against heartwater with inactivated Cowdria ruminantium

Mahan, Suman M.; Andrew, H. R.; Tebele, N; Burridge, M. J.; Barbet, Anthony F.

doi:10.1016/0034-5288(95)90087-x

Cited by 59 publications

(33 citation statements)

References 15 publications

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“…The veterinary literature contains convincing reports that immunization of animals with inactivated E. ruminantium stimulates their ability to survive an ordinarily highly lethal infection (24,25,28). Similar enhanced survival follows vaccination with live attenuated E. ruminantium or deliberate infection of animals followed by treatment with tetracycline (15).…”

Section: Discussionmentioning

confidence: 99%

Mechanisms of Immunity toEhrlichia muris: a Model of Monocytotropic Ehrlichiosis

Feng

Walker

2004

Infect Immun

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Ehrlichia species can cause life-threatening infections or chronic persistent infections. Mechanisms of protective immunity were examined in an Ehrlichia muris mouse model of monocytotropic ehrlichiosis. C57BL/6 mice possessed strong genetic resistance to E. muris of an undetermined mechanism. CD8 T lymphocytes were particularly important, as revealed by 81% fatalities for E. muris-infected, major histocompatibility complex class I gene knockout mice compared with no deaths for wild-type C3H mice. Moreover, 80% of C3H mice depleted of CD8 and CD4 cells died of E. muris infection compared with only 44% of CD4 cell-depleted mice. CD8 T lymphocytes were demonstrated for the first time in an Ehrlichia infection to exhibit cytotoxic T-lymphocyte activity against Ehrlichia-infected target cells. Both gamma interferon and tumor necrosis factor were shown to play synergistic roles in protective immunity in vivo for the first time, as demonstrated by 75% fatalities when both cytokines were neutralized compared with minimal mortality when they were depleted separately. Passive transfer of antibodies, but not Fab fragments, to E. muris protected C3H/SCID mice against lethal infection. The mechanism of increased susceptibility (22% lethality) of C57BL/6 major histocompatibility complex class II gene knockout mice and CD4 cell-depleted C3H mice (i.e., through a gamma interferon or antibody mechanism), as well as the more important role of CD8 T lymphocytes (in the form of cytotoxic T-lymphocyte activity and/or gamma interferon production), remains to be elucidated. Protective immunity against monocytotropic E. muris is mediated by a combination of CD8 and CD4 T lymphocytes, gamma interferon, tumor necrosis factor alpha, and antibodies.

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Section: Discussionmentioning

confidence: 99%

Mechanisms of Immunity toEhrlichia muris: a Model of Monocytotropic Ehrlichiosis

Feng

Walker

2004

Infect Immun

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“…The bacteria are chemically inactivated, formulated with a suitable adjuvant, and administered subcutaneously. The original vaccine was developed in Guadeloupe, using the local Gardel isolate (66), and a modified version was subsequently produced in Zimbabwe, using the local Crystal Springs isolate (67). An early problem with the inactivated vaccine was the difficulty, and therefore high cost, of preparing enough of the antigenic material for large-scale use.…”

Section: Inactivated Vaccine Developmentmentioning

confidence: 99%

Heartwater – Ehrlichia ruminantium infection

Allsopp¹

2015

Rev. Sci. Tech. OIE

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SummaryHeartwater is a notifiable disease that is listed by the World Organisation for Animal Health. It is caused by Ehrlichia ruminantium, an obligately intracellular Gramnegative bacterium in the order Rickettsiales and the family Anaplasmataceae. The disease is borne by ticks in the genus Amblyomma and causes heartwater, or cowdriosis, in wild and domestic ruminants, primarily in Africa, but also in parts of the Caribbean. The disease was recognised in South Africa in the 19th Century and determined to be tick borne in 1900, while the organism was identified in 1925 and first cultured in vitro in 1985. This latter achievement boosted research into the disease at a time when biology was moving into the molecular genetic age. Over the last 20 years, there have been significant improvements in our understanding of E. ruminantium, yielding major advances in diagnosis, epidemiology, genetic characterisation, phylogeny, immunology, and vaccine development. The organism is genetically highly variable; this has important implications for future control measures, and is making it difficult to develop an effective vaccine for protection against tick challenge. Research is continuing into three different types of vaccine, inactivated, attenuated, and recombinant, and the current state of development of each is discussed. KeywordsAmblyomma hebraeum -Amblyomma variegatum -Attenuated vaccine -ControlCowdriosis -Diagnosis -Economic importance -Ehrlichia ruminantium -Heartwater -Inactivated vaccine -Occurrence -Recombinant vaccine -Tick-borne disease.Rev. Sci. Tech. Off. Int. Epiz., 2015, 34 (2), 557-568 AetiologyHeartwater is listed by the World Organisation of Animal Health as a notifiable disease (1). It was known in South Africa for nearly 90 years before the causative organism was identified in 1925 as a rickettsia, originally named Rickettsia ruminantium (2, 3). The name was later changed to Cowdria ruminantium (4), from which arose the term 'cowdriosis'. Molecular phylogenetic studies of the Rickettsiales in the 1990s uncovered the real evolutionary relationships within the order and the organism was reclassified as Ehrlichia ruminantium in the family Anaplasmataceae (5). Ehrlichia ruminantium, which is transmitted by Amblyomma ticks, is obligately intracellular, infects cattle, sheep, goats and some wild ruminants, and is frequently fatal. A comprehensive account of the history and biology of E. ruminantium can be found elsewhere (6). Economic and social importanceHeartwater is a serious economic problem wherever it occurs, in an enormous area covering most of sub-Saharan Africa, its offshore islands, and several islands in the Caribbean. The disease generally prevents livestock farmers from upgrading their herds to modern high-yielding breeds, as these are more susceptible to infection than traditional stock breeds, which often have a measure of resistance (7). Since heartwater is so common in the endemic areas of Africa, farmers are usually unwilling or unable to pay for definitive diagnoses, so it is difficul...

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“…Previous reports have highlighted that immunization against phylogenetically related organisms such as Ehrlichia ruminantium and Ehrlichia risticii, using inactivated organisms can induce protection against live challenge (Rikihisa 1991;Dame, Mahan & Yowell 1992;Van Vliet, Jongejan & Zeijst 1992;Martinez, Maillard, Coisne, Sheikboudou & Bensaid 1994;Mahan, Andrew, Tebele, Burridge & Barbet 1995;Martinez, Perez, Sheikboudou, Debus & Bensaid 1996;Mahan, Kumbula, Burridge & Barbet 1998;Dumler, Barbet, Bekker, Dasch, Palmer, Ray, Rikihisa & Rurangirwa 2001;Mahan, Smith, Kumbula, Burridge & Barbet 2001). In this study, we demonstrate that immunization of German Shepherd dogs (GSDs) with inactivated E. canis organisms in combination with Quil A induces humoral and cellular immune responses which exert a suppressive effect on rickettsaemia following live E. canis challenge.…”

mentioning

confidence: 62%

“…For immunization, freshly harvested live E. canis organisms were inactivated with an equal volume of 0.8 % β-propiolactone in sterile PBS on ice for 2 h and frozen overnight at -20°C as described by Mahan et al (1995) for inactivation of E. ruminantium. Inactivation of the organisms was confirmed by staining with 6-carboxy-fluoresceine-diacetate (6-CFDA; Sigma, St. Louis, MO, USA) which only stains live cells.…”

Section: Preparation Of E Canis Antigenmentioning

confidence: 99%

A preliminary study to evaluate the immune responses induced by immunization of dogs with inactivated <i>Ehrlichia canis</i> organisms

Mahan¹,

Kelly²,

Mahan³

2005

Onderstepoort J Vet Res

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Ehrlichia canis is an intracellular pathogen that causes canine monocytic ehrlichiosis. Although the role of antibody responses cannot be discounted, control of this intracellular pathogen is expected to be by cell mediated immune responses. The immune responses in dogs immunized with inactivated E. canis organisms in combination with Quil A were evaluated. Immunization provoked strong humoral and cellular immune responses, which were demonstrable by Western blotting and lymphocyte proliferation assays. By Western blotting antibodies to several immunodominant E. canis proteins were detected in serum from immunized dogs and antibody titres increased after each immunization. The complement of immunogenic proteins recognized by the antisera were similar to those recognized in serum from infected dogs. Upon challenge with live E. canis, rapid anamnestic humoral responses were detected in the serum of immunized dogs and primary antibody responses were detected in the serum from control dogs. Following immunization, a lymphocyte proliferative response (cellular immunity) was detected in peripheral blood mononuclear cells (PBMNs) of immunized dogs upon stimulation with E. canis antigens. These responses were absent from non-immunized control dogs until after infection with live E. canis, when antigen specific-lymphocyte proliferation responses were also detected in the PBMNs of the control dogs. It can be thus concluded that immunization against canine monocytic ehrlichiosis may be feasible. However, the immunization regimen needs to be optimized and a detailed investigation needs to be done to determine if this regimen can prevent development of acute and chronic disease.

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Immunisation of sheep against heartwater with inactivated Cowdria ruminantium

Cited by 59 publications

References 15 publications

Mechanisms of Immunity toEhrlichia muris: a Model of Monocytotropic Ehrlichiosis

Mechanisms of Immunity toEhrlichia muris: a Model of Monocytotropic Ehrlichiosis

Heartwater – Ehrlichia ruminantium infection

A preliminary study to evaluate the immune responses induced by immunization of dogs with inactivated <i>Ehrlichia canis</i> organisms

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