Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

A study of Jembrana disease virus and its role in Jembrana disease in Bali cattle

Kertayadnya, Gde (1994) A study of Jembrana disease virus and its role in Jembrana disease in Bali cattle. PhD thesis, Murdoch University.

[img]
PDF - Whole Thesis
Available Upon Request

Abstract

The literature on Jembrana disease, a disease apparently unique to Bali (Bos javanicus) cattle, was reviewed. Emphasis was placed on the comparative features of Jembrana disease and other diseases in cattle and some other animal species.

A detailed study was made of the clinical and haematological changes in experimentally induced Jembrana disease in Bali cattle. The major clinical signs were an elevated rectal body temperature persisting for 7 days (range 5 to 12 days), lethargy, anorexia, and enlargement of the superficial lymph nodes. A mild ocular and nasal discharge, diarrhoea with blood in the faeces, and pallor of the mucous membranes also occurred in some animals. Major haematological changes included leukopenia (associated with lymphopenia, eosinopenia and slight neutropenia), mild thrombocytopenia, normocytic normochromic anaemia, elevated blood urea levels, and reduced total plasma protein. The mortality rate in the experimentally-infected cattle was 17%.

Infections of other cattle species and buffaloes (Bubalus bubalis) were undertaken to confirm the apparent host specificity of Jembrana disease for Bali cattle. Infection of Ongole cattle (Bos indicus) and buffaloes (Bubalus bubalis) induced a mild febrile response after infection but no other overt clinical signs of the disease. Crossbred Bali (Bos javanicus x Bos indicus) cattle, and Friesian (Bos taurus) cattle developed lesions that were consistent with those detected in Bali cattle with Jembrana disease but the lesions were markedly less severe than in Bali cattle, and some changes that consistently occurred in Bali cattle were not detected. Small ruminant species (sheep and goats) did not develop clinical changes after infection.

A high titre of the infectious agent associated with Jembrana disease (about 108 infectious doses per ml) was detected in blood of Bali cattle during the febrile period of the disease. The agent persisted in blood for 25 months after clinical recovery. Ongole cattle, crossbred Bali x Ongole cattle, Friesian cattle, buffaloes and sheep also developed a persistent infection after inoculation.

The properties of the infectious agent present in plasma of infected Bali cattle were determined. The agent was shown by exclusion membrane filtration to be 50 to 100 nm in size, providing evidence that the infectious agent was a virus and not a rickettsia-like agent as previously proposed. The virus had characteristics of viruses in the family Retroviridae, including electron microscopic observations of size (75-130 nm), morphology and morphogenesis of the virions in plasma and tissues from affected animals, density (1.15 g/ml) in sucrose gradients, and the presence of an intravirion reverse transcriptase. The morphology and apparent morphogenesis of the virions most closely resembled viruses in the subfamily Lentivirinae. Further evidence of the relationship of the virus to lentiviruses was the demonstration by Western immunoblotting procedures with polyclonal bovine antiserum of an antigenic relationship of the immunodominant 26K protein of JDV to the 26K capsid protein of BIV. The virus was designated Jembrana disease virus (JDV).

An enzyme-linked immunosorbent assay (ELISA) was developed that detected antibody to JDV. In Bali cattle, antibody production was delayed and was not detected in most cattle until 11 weeks after infection, and a maximum antibody response was detected 23 to 33 weeks after infection. Antibody was still detectable in most cattle 59 weeks after infection. A similar antibody response was also detected in nearly all crossbred Bali (Madura and Rambon) cattle that were infected with JDV, although these types of cattle developed only a mild or subclinical infection.

Clinical and pathological evidence that Jembrana disease occurred in cattle from Bali island, Lampung and West Sumatra provinces in Sumatra island, East Java, and South Kalimantan provinces but not in other areas of Indonesia was confirmed by the detection of antibody in cattle from these areas but not from other areas of Indonesia. The serological results confirmed epidemiological evidence that there has been limited spread of Jembrana disease from endemic areas to adjacent areas.

Monoclonal antibodies were produced against 2 virion proteins of JDV. These were used to confirm the antigenic relationship between the 26K protein of JDV and the cognate protein of BIV. The monoclonal antibodies were also to develop an immunocytochemical assay for the detection of JDV antigens in tissues of infected cattle. This procedure could be used for confirming a clinical and pathological diagnosis of Jembrana disease in individual Bali cattle.

Item Type: Thesis (PhD)
Murdoch Affiliation: School of Veterinary Studies
Notes: Note to the author: If you would like to make your thesis openly available on Murdoch University Library's Research Repository, please contact: repository@murdoch.edu.au. Thank you.
Supervisor(s): Wilcox, Graham
URI: http://researchrepository.murdoch.edu.au/id/eprint/53281
Item Control Page Item Control Page