Livestock farming across the world is constantly threatened by evolutionary turnover of foot-and-mouth disease virus (FMDV) strains in endemic systems, the underlying dynamics of which remain to be elucidated. Here, we map the eco-evolutionary landscape of co-circulating FMDV lineages within an important endemic virus pool encompassing Western, Central and parts of Southern Asia, reconstructing the evolutionary history and spatial dynamics over the last 20 years that shapes the current epidemiological situation. We demonstrate that new FMDV variants periodically emerge from Southern Asia, precipitating waves of virus incursions that systematically travel in a westerly direction. We evidence how metapopulation dynamics drive the emergence and extinction of spatially structured virus populations, and how transmission in different host species regulates the evolutionary space of virus serotypes. Our work provides the first integrative framework that defines co-evolutionary signatures of FMDV in regional contexts to help understand the complex interplay between virus phenotypes, host characteristics, and key epidemiological determinants of transmission that drive FMDV evolution in endemic settings.
The economic impact of abortions in ruminant breeders is one of the biggest problems in livestock. Of the infectious agents, viruses, especially herpesviruses and pestiviruses, are the most important causative agents of abortion in ruminants. In the present study, the role of herpesviruses (bovine herpesvirus-1 (BoHV-1), bovine herpesvirus-4 (BoHV-4)) and pestiviruses (bovine viral diarrhea virus (BVDV), border disease virus (BDV)) was investigated in cases of ruminant abortion between 2007 and 2015 in western Turkey. Out of 81 aborted fetal samples (60 calves, 19 lambs, and 2 kids), 42 were positive, which included 31 calves, 9 lambs, and 2 goats; 39 aborted fetal samples were negative for the pestivirus antigen ELISA. BoHV-1 antigen ELISA was positive in 3 cases which included 2 calves and 1 lamb; the remainder 78 cases were negative. Pestivirus and BoHV-1 were positive in 51.85 and 3.70 %, respectively, of the samples. According to PCR analysis, BoHV-4 was not encountered in any of the tested samples. In one of the calf fetus samples, both BVDV and BoHV-1 were positive; in one of the lamb fetus samples, BoHV-1 was positive. There was a much higher level of pestivirus antigen than the other viral agents evaluated in the study (p < 0.0001). The results of this study indicate that pestiviruses are a common viral cause of ruminant abortions in the examined area.
Purpose Foot-and-mouth disease (FMD) and anthrax are important diseases in sheep. Vaccination is a favorable strategy against both infections. Simultaneous administration of vaccines does generally not impede the immune responses of each other, although there are some exceptions, and it may help reduce the labor and costs of vaccination as well as distress on animals. Although oil adjuvant FMD vaccine has been tried with live anthrax vaccine in cattle, there are no reports on the simultaneous use of both vaccines in sheep. Materials and Methods In this study, FMD seronegative sheep were used to investigate the impact of the simultaneous vaccination of FMD and anthrax on FMD antibody titers of sheep. Virus neutralization test and liquid phase blocking enzyme-linked immunosorbent assay were used to determine the antibody response to the FMD vaccine. Results The results demonstrated that both vaccines can be used simultaneously without any interference with the FMD response. Moreover, the simultaneous administration with anthrax vaccine had a stimulating effect on the early (day 7 post-vaccination) virus neutralization antibody response to the FMD vaccine. Conclusion The simultaneous use of the FMD and anthrax vaccines did not hinder the response to the FMD vaccine in sheep.
Pestivirus infections have a huge economic impact on livestock production. In 2014, an aborted fetus from a sheep flock suffering from abortus and diarrhea was submitted for virological diagnosis. Due to the positive result of the sample for pestivirus and continuing clinical symptoms in the flock, all of the animals were sampled individually. Blood samples for serum and peripheral blood mononuclear cells were collected from 93 animals (5 rams, 26 lambs, and 62 sheep). During sampling 1 ocular and 4 rectal swab samples were obtained from lambs that had a clinical eye problem and diarrhea, respectively. Additionally 5 aborted fetuses were submitted after the initial sampling. Thirteen of the 93 blood samples tested positive for pestivirus by antigen-detection ELISA. Propagation of noncytopathogenic virus was detected in blood samples from 6 lambs and in 1 aborted fetus sample by using the indirect immunoperoxidase monolayer assay. Pestivirus RNA was detected in 10 of 13 samples by RT-PCR employing pan-pestivirus primers. Border disease virus (BDV) RNA was identified with PBD1/PBD2 specific primers in all 10 samples that tested positive for pan-pestivirus primers. Differentiating RT-PCR further identified BVDV-1 sequences in 3 of the 10 samples. The Sequenced BDV strain (KY-57) was located in the cluster of BDV-7 (Aydin-like) while the BVDV strain was close close to BVDV-1c. The results of this study highlight the possibility of dual infection in sheep with BDV and BVDV-1.
There are several commonly used diagnostic methods to detect pestiviruses for routine diagnostic purposes. In the present study, we aimed to compare virus isolation-indirect immunoperoxidase monolayer assay (VI-IIPMA), antigen capture ELISA (ACE), and RT-PCR for the detection of pestiviruses in clinical samples. Out of 246 samples tested (11 serum, 119 swab, 116 tissue), 28 samples (11.39%) were positive and 218 (88.61%) were negative using the VI-IIPMA method. Using ACE, 70 samples (28.46%) were positive and 176 (71.54%) were negative. Finally, using RT-PCR analysis, we detected 19 (7.72%) positive and 227 (92.28%) negative samples. Inconsistencies were observed among results of the three methods: 8 samples were positive using VI-IIPMA but negative using ACE and RT-PCR. In addition, 4 samples that were found to be negative by VI-IIPMA were found to be positive by ACE and RT-PCR. Five samples were positive by ACE and VI-IIPMA. However, 46 samples were found to be positive only by ACE. These results show that the number of positive results detected by ACE is higher than that by VI-IIPMA and RT-PCR. Although ACE may prove advantageous for diagnosing pestiviruses, using a second method in combination with ACE will improve the validity of the results.
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