The isolation of a probable pestivirus from a goat

First study on genetic variability of bovine viral diarrhea virus isolated from Sapera dairy goats with reproductive disorders in Yogyakarta, Indonesia

Background and Aim:

Bovine viral diarrhea (BVD) virus (BVDV) is an important viral pathogen of cattle that can infect diverse artiodactyl species. The clinical manifestations caused by BVDV in heterologous hosts, as they do in cattle, vary, although respiratory and reproductive failures are commonly reported. BVDV infections commonly result in reproductive failure in goats, with abortion being the primary clinical sign. In central Java, Indonesia, BVDV infection has been reported in two clinically healthy local goat species, and the testing indicated infection by BVDV Type 1. However, the genetic diversity of viruses has not been described in healthy or ill goats. The objectives of the present study were as follows: (1) To investigate the genetic variation of BVDV isolated from Sapera dairy goats with naturally occurring reproductive disorders in Yogyakarta, Indonesia, using the 5’ untranslated region (5’ UTR) and (2) to study the possible correlation between reproductive disorders and the presence of BVDV in the flock.

Materials and Methods:

Blood samples were collected in October 2021 from 39 goats that had been individually reported to have reproductive disorders. The serum samples were subjected to molecular detection and genetic characterization of BVDV based on the 5’ UTR of the viral genome, followed by sequencing and phylogenetic analyses. Viral isolation was performed on BVDV-positive samples to analyze the viral biotypes.

Results:

BVDV infection was detected in five out of 39 female goats. The clinical status of the BVDV-infected goats was abortion (n=2), metritis (n=1), and repeated breeding (n=2). All antigen-positive samples were confirmed as BVDV type 1a (BVDV-1a) and noncytopathic (NCP)-BVDV biotype.

Conclusion:

The BVDV-1a and NCP biotypes are the main subtypes and biotypes present in Sapera dairy goats exhibiting reproductive failure. This result is consistent with previous results in dairy cattle in Yogyakarta. The reported results can facilitate the design of methods for the prevention and control of BVD circulating in Indonesia.

Ruminant pestivirus infections in animals other than cattle and sheep

The current knowledge on infection with ruminant pestiviruses in animals other than cattle and sheep and reviewed. Natural infection is found to occur in goats, in captive and free-living ruminants, as well as in pigs. The viral agent, susceptible species, epidemiology, clinicopathologic lesions, pathogenesis, diagnosis, control, and consequences for control programs in domestic ruminants are discussed.

Pathomorphological and immunohistological findings in progeny of goats experimentally infected with pestiviruses

A total of 25 pregnant goats without neutralizing antibodies against BVD virus were inoculated with two different pestivirus isolates at eight different stages of gestation. In both infection groups, various malformations were observed in fetuses and neonates. In three twins with neutralizing antibodies against BVD virus leukoencephalomalacia occurred, characterized by gelatinous transformation in the cerebral hemispheres. These lesions were comparable to alterations described in alternative pathology of Border disease in sheep. Although the immunohistological findings are characteristic for immunological tolerance and viral persistence, viable offspring persistently infected with pestivirus was not observed.

BVD-virus infection in goats-experimental studies on transplacental transmissibility of the virus and its effect on reproduction

Eight groups of altogether 25 goats without neutralizing antibodies against BVD virus, were inoculated either intranasally or intranasally and subcutaneously with two different BVD virus isolates during different stages of gestation. In all 18 goats inoculated within the first 78 days of gestation an abortion and foetal death rate of approximately 100% occurred. Only one goat gave birth to a clinically healthy kid. The other seven goats which were inoculated after the 78th day of gestation showed also a high foetal death rate. Only two of them gave birth to clinically healthy kids. Neutralizing antibodies against BVD virus could be detected in blood samples drawn from 14 kids born at normal term including stillborn and non-viable offsprings. BVD virus was reisolated from different organs taken from seven foetuses. It was not possible to isolate BVD virus from any of the normal offsprings.

Experimental infection of pregnant goats with swine fever virus

Thirteen pregnant goats were inoculated intravenously with the ALD strain of virulent swine fever (SF) virus on Days 64-84 of gestation. Dams showed transient and mild viremia, and produced high serum neutralizing (SN) antibody after inoculation. Six inoculated dams were reared until parturition occurred and bore six apparently normal, one apparently normal but dead, one mummified and three edematous kids. Neutralizing antibody was demonstrated in the pre-colostral sera obtained from all normal kids, but no SF virus was isolated from any of them. The other seven dams were killed on post-inoculation days (PID) 5-61, and fetuses, placenta and amnion were tested for the virus and SN antibody. All fetuses of five dams examined within PID 40 were positive for SF virus, but negative for SN antibody. SF virus was also isolated from one of three fetuses examined on PID 61. Conversely, the other two fetuses examined on PID 61 were negative for SF virus, but positive for SN antibody. Furthermore, SF virus was isolated from the placenta and amnion of all the dams.