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1.
Microbiol Resour Announc ; 11(2): e0116721, 2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35112907

RESUMO

Here, we report the genome of bovine viral diarrhea virus 1 (BVDV-1) contaminating a continuous fetal bovine kidney cell line. The cell line (LFBK-αVß6) is used for the rapid isolation and serotyping of foot-and-mouth disease virus (FMDV). The sequence contains the full polyprotein-coding sequence and partial untranslated regions (UTRs).

2.
Antiviral Res ; 199: 105244, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35026307

RESUMO

Human infection with Crimean-Congo hemorrhagic fever virus (CCHFV), a tick-borne pathogen in the family Nairoviridae, can result in a spectrum of outcomes, ranging from asymptomatic infection through mild clinical signs to severe or fatal disease. Studies of CCHFV immunobiology have investigated the relationship between innate and adaptive immune responses with disease severity, attempting to elucidate factors associated with differential outcomes. In this article, we begin by highlighting unanswered questions, then review current efforts to answer them. We discuss in detail current clinical studies and research in laboratory animals on CCHF, including immune targets of infection and adaptive and innate immune responses. We summarize data about the role of the immune response in natural infections of animals and humans and experimental studies in vitro and in vivo and from evaluating immune-based therapies and vaccines, and present recommendations for future research.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Carrapatos , Animais
3.
Pathogens ; 10(10)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34684213

RESUMO

Vesicular stomatitis virus (VSV) emerges periodically from its focus of endemic transmission in southern Mexico to cause epizootics in livestock in the US. The ecology of VSV involves a diverse, but largely undefined, repertoire of potential reservoir hosts and invertebrate vectors. As part of a larger program to decipher VSV transmission, we conducted a study of the spatiotemporal dynamics of Simulium black flies, a known vector of VSV, along the Rio Grande in southern New Mexico, USA from March to December 2020. Serendipitously, the index case of VSV-Indiana (VSIV) in the USA in 2020 occurred at a central point of our study. Black flies appeared soon after the release of the Rio Grande's water from an upstream dam in March 2020. Two-month and one-year lagged precipitation, maximum temperature, and vegetation greenness, measured as Normalized Difference Vegetation Index (NDVI), were associated with increased black fly abundance. We detected VSIV RNA in 11 pools comprising five black fly species using rRT-PCR; five pools yielded a VSIV sequence. To our knowledge, this is the first detection of VSV in the western US from vectors that were not collected on premises with infected domestic animals.

4.
Viruses ; 13(9)2021 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-34578392

RESUMO

Mosquito-borne West Nile virus (WNV) is the causative agent of West Nile disease in humans, horses, and some bird species. Since the initial introduction of WNV to the United States (US), approximately 30,000 horses have been impacted by West Nile neurologic disease and hundreds of additional horses are infected each year. Research describing the drivers of West Nile disease in horses is greatly needed to better anticipate the spatial and temporal extent of disease risk, improve disease surveillance, and alleviate future economic impacts to the equine industry and private horse owners. To help meet this need, we integrated techniques from spatiotemporal epidemiology, eco-phylogenetics, and distributional ecology to assess West Nile disease risk in horses throughout the contiguous US. Our integrated approach considered horse abundance and virus exposure, vector and host distributions, and a variety of extrinsic climatic, socio-economic, and environmental risk factors. Birds are WNV reservoir hosts, and therefore we quantified avian host community dynamics across the continental US to show intra-annual variability in host phylogenetic structure and demonstrate host phylodiversity as a mechanism for virus amplification in time and virus dilution in space. We identified drought as a potential amplifier of virus transmission and demonstrated the importance of accounting for spatial non-stationarity when quantifying interaction between disease risk and meteorological influences such as temperature and precipitation. Our results delineated the timing and location of several areas at high risk of West Nile disease and can be used to prioritize vaccination programs and optimize virus surveillance and monitoring.


Assuntos
Surtos de Doenças/veterinária , Reservatórios de Doenças/veterinária , Ecologia , Filogenia , Análise Espaço-Temporal , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/classificação , Vírus do Nilo Ocidental/genética , Animais , Aves/virologia , Culicidae/virologia , Reservatórios de Doenças/virologia , Cavalos/virologia , Mosquitos Vetores/virologia , Estações do Ano , Febre do Nilo Ocidental/transmissão
5.
Pathogens ; 10(9)2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34578166

RESUMO

The molecular mechanisms associated with the pathogenesis of vesicular stomatitis virus (VSV) in livestock remain poorly understood. Several studies have highlighted the relevant role of macrophages in controlling the systemic dissemination of VSV during infection in different animal models, including mice, cattle, and pigs. To gain more insight into the molecular mechanisms used by VSV to impair the immune response in macrophages, we used microarrays to determine the transcriptomic changes produced by VSV infection in primary cultures of porcine macrophages. The results indicated that VSV infection induced the massive expression of multiple anorexic, pyrogenic, proinflammatory, and immunosuppressive genes. Overall, the interferon (IFN) response appeared to be suppressed, leading to the absence of stimulation of interferon-stimulated genes (ISG). Interestingly, VSV infection promoted the expression of several genes known to downregulate the expression of IFNß. This represents an alternate mechanism for VSV control of the IFN response, beyond the recognized mechanisms mediated by the matrix protein. Although there was no significant differential gene expression in macrophages infected with a highly virulent epidemic strain compared to a less virulent endemic strain, the endemic strain consistently induced higher expression of all upregulated cytokines and chemokines. Collectively, this study provides novel insights into VSV molecular pathogenesis and immune evasion that warrant further investigation.

6.
Pathogens ; 10(8)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34451394

RESUMO

In 2006, vesicular stomatitis New Jersey virus (VSNJV) caused outbreaks in Wyoming (WY) horses and cattle after overwintering in 2004 and 2005. Within two weeks of the outbreak onset, 12,203 biting flies and 194 grasshoppers were collected near three equine-positive premises in Natrona County, WY. Insects were identified to the species level and tested by RT-qPCR for VSNJV polymerase (L) and phosphoprotein (P) gene RNA. Collected dipterans known to be competent for VSV transmission included Simulium black flies and Culicoides biting midges. VSNJV L and P RNA was detected in two pools of female Simulium bivittatum and subjected to partial genome sequencing. Phylogenetic analysis based on the hypervariable region of the P gene from black flies showed 100% identity to the isolate obtained from the index horse case on the same premises. This is the first report of VSNJV in S. bivittatum in WY and the first field evidence of possible VSV maintenance in black fly populations during an outbreak.

7.
Mol Ecol ; 30(15): 3815-3825, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34008868

RESUMO

The continued endemicity of foot and mouth disease virus (FMDV) in East Africa has significant implications for livestock production and poverty reduction, yet its complex epidemiology in endemic settings remains poorly understood. Identifying FMDV dispersal routes and drivers of transmission is key to improved control strategies. Environmental heterogeneity and anthropogenic drivers (e.g., demand for animal products) can impact viral spread by influencing host movements. Here, we utilized FMDV serotype O VP1 genetic sequences and corresponding spatiotemporal data in order to (i) infer the recent dispersal history, and (II) investigate the impact of external factors (cattle density, human population density, proximity to livestock markets, and drought) on dispersal velocity, location, and direction of FMDV serotype O in East Africa. We identified statistical evidence of long-distance transmission events, and we found that FMDV serotype O tends to remain circulating in areas of high cattle density, high human population density, and in close proximity to livestock markets. The latter two findings highlight the influence of anthropogenic factors on FMDV serotype O spread in this region. These findings contribute to the understanding of FMDV epidemiology in East Africa and can help guide improved control measures.


Assuntos
Vírus da Febre Aftosa , Febre Aftosa , África Oriental/epidemiologia , Animais , Bovinos , Surtos de Doenças , Febre Aftosa/epidemiologia , Vírus da Febre Aftosa/genética , Filogenia , Sorogrupo
8.
Front Vet Sci ; 8: 783198, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34988142

RESUMO

Vesicular stomatitis virus (VSV) causes a disease in susceptible livestock that is clinically indistinguishable from foot-and-mouth disease. Rapid testing is therefore critical to identify VSV and rule out FMD. We previously developed and validated a multiplex real-time reverse transcription polymerase chain reaction assay (mRRT-PCR) for detection of both VS New Jersey virus (VSNJV) and VS Indiana virus (VSIV). However, it was subsequently apparent that this assay failed to detect some VSNJV isolates in Mexico, especially in genetic group II, lineage 2.1. In order to enhance the sensitivity of the mRRT-PCR for VSNJV, parts of the assay were redesigned and revalidated using new and improved PCR chemistries. The redesign markedly improved the assay by increasing the VSNJV detection sensitivity of lineage 2.1 and thereby allowing detection of all VSNJV clades. The new assay showed an increased capability to detect VSNJV. Specifically, the new mRRT-PCR detected VSNJV in 100% (87/87) of samples from Mexico in 2006-2007 compared to 74% for the previous mRRT-PCR. Furthermore, the analytical sensitivity of the new mRRT-PCR was enhanced for VSNJV. Importantly, the modified assay had the same sensitivity and specificity for VSIV as the previously published assay. Our results highlight the challenges the large genetic variability of VSV pose for virus detection by mRRT-PCR and show the importance of frequent re-evaluation and validation of diagnostic assays for VSV to ensure high sensitivity and specificity.

9.
Front Vet Sci ; 7: 554305, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088833

RESUMO

Inactivated, wild-type foot-and-mouth disease virus (FMDV) vaccines are currently used to control FMD around the world. These traditional FMD vaccines are produced using large quantities of infectious, virulent, wild-type FMD viruses, with the associated risk of virus escape from manufacturing facilities or incomplete inactivation during the vaccine formulation process. While higher quality vaccines produced from wild-type FMDV are processed to reduce non-structural antigens, there is still a risk that small amounts of non-structural proteins may be present in the final product. A novel, antigenically marked FMD-LL3B3D vaccine platform under development by Zoetis, Inc. and the USDA-ARS, consists of a highly attenuated virus platform containing negative antigenic markers in the conserved non-structural proteins 3Dpol and 3B that render resultant vaccines fully DIVA compatible. This vaccine platform allows for the easy exchange of capsid coding sequences to create serotype-specific vaccines. Here we demonstrate the efficacy of the inactivated FMD-LL3B3D-A24 Cruzeiro vaccine in cattle against wild-type challenge with A24 Cruzerio. A proprietary adjuvant system was used to formulate the vaccines that conferred effective protection at low doses while maintaining the DIVA compatibility. In contrast to wild-type FMDV, the recombinant FMD-LL3B3D mutant viruses have been shown to induce no clinical signs of FMD and no shedding of virus in cattle or pigs when inoculated as a live virus. The FMD-LL3B3D vaccine platform, currently undergoing development in the US, provides opportunities for safer vaccine production with full DIVA compatibility in support of global FMDV control and eradication initiatives.

10.
Front Vet Sci ; 7: 340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32637426

RESUMO

Foot-and-mouth disease virus (FMDV) causes persistent infection of nasopharyngeal epithelial cells in ~50% of infected ruminants. The mechanisms involved are not clear. This study provides a continued investigation of differentially expressed genes (DEG) identified in a previously published transcriptomic study analyzing micro-dissected epithelial samples from FMDV carriers and non-carriers. Pathway analysis of DEG indicated that immune cell trafficking, cell death and hematological system could be affected by the differential gene expression. Further examination of the DEG identified five downregulated (chemerin, CCL23, CXCL15, CXCL16, and CXCL17) and one upregulated (CCL2) chemokines in carriers compared to non-carriers. The differential expression could reduce the recruitment of neutrophils, antigen-experienced T cells and dendritic cells and increase the migration of macrophages and NK cells to the epithelia in carriers, which was supported by DEG expressed in these immune cells. Downregulated chemokine expression could be mainly due to the inhibition of canonical NFκB signaling based on DEG in the signaling pathways and transcription factor binding sites predicted from the proximal promoters. Additionally, upregulated CD69, IL33, and NID1 and downregulated CASP3, IL17RA, NCR3LG1, TP53BP1, TRAF3, and TRAF6 in carriers could inhibit the Th17 response, NK cell cytotoxicity and apoptosis. Based on our findings, we hypothesize that (1) under-expression of chemokines that recruit neutrophils, antigen-experienced T cells and dendritic cells, (2) blocking NK cell binding to target cells and (3) suppression of apoptosis induced by death receptor signaling, viral RNA, and cell-mediated cytotoxicity in the epithelia compromised virus clearance and allowed FMDV to persist. These hypothesized mechanisms provide novel information for further investigation of persistent FMDV infection.

11.
Trop Med Infect Dis ; 5(3)2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32645889

RESUMO

Crimean-Congo hemorrhagic fever virus (CCHFV) infection is identified in the 2018 World Health Organization Research and Development Blueprint and the National Institute of Allergy and Infectious Diseases (NIH/NIAID) priority A list due to its high risk to public health and national security. Tick-borne CCHFV is widespread, found in Europe, Asia, Africa, the Middle East, and the Indian subcontinent. It circulates between ticks and several vertebrate hosts without causing overt disease, and thus can be present in areas without being noticed by the public. As a result, the potential for zoonotic spillover from ticks and animals to humans is high. In contrast to other emerging viruses, human-to-human transmission of CCHFV is typically limited; therefore, prevention of spillover events should be prioritized when considering countermeasures. Several factors in the transmission dynamics of CCHFV, including a complex transmission cycle that involves both ticks and vertebrate hosts, lend themselves to a One Health approach for the prevention and control of the disease that are often overlooked by current strategies. Here, we examine critical focus areas to help mitigate CCHFV spillover, including surveillance, risk assessment, and risk reduction strategies concentrated on humans, animals, and ticks; highlight gaps in knowledge; and discuss considerations for a more sustainable One Health approach to disease control.

12.
Front Microbiol ; 11: 1123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32587580

RESUMO

In this study, we explore the virulence of vesicular stomatitis New Jersey virus (VSNJV) in pigs and its potential relationship with the virus's ability to modulate innate responses. For this purpose, we developed a mutant of the highly virulent strain NJ0612NME6, containing a single amino acid substitution in the matrix protein (M51R). The M51R mutant of NJ0612NME6 was unable to suppress the transcription of genes associated with the innate immune response both in primary fetal porcine kidney cells and porcine primary macrophage cultures. Impaired viral growth was observed only in porcine macrophage cultures, indicating that the M51 residue is required for efficient replication of VSNJV in these cells. Furthermore, when inoculated in pigs by intradermal scarification of the snout, M51R infection was characterized by decreased clinical signs including reduced fever and development of less and smaller secondary vesicular lesions. Pigs infected with M51R had decreased levels of viral shedding and absence of RNAemia compared to the parental virus. The ability of the mutant virus to infect pigs by direct contact remained intact, indicating that the M51R mutation resulted in a partially attenuated phenotype capable of causing primary lesions and transmitting to sentinel pigs. Collectively, our results show a positive correlation between the ability of VSNJV to counteract the innate immune response in swine macrophage cultures and the level of virulence in pigs, a natural host of this virus. More studies are encouraged to evaluate the interaction of VSNJV with macrophages and other components of the immune response in pigs.

13.
J Equine Vet Sci ; 90: 103026, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32534788

RESUMO

Vesicular stomatitis viruses (VSVs) cause a condition known as vesicular stomatitis (VS), which results in painful lesions in equines, cattle, swine, and camelids, and when transmitted to humans, can cause flu-like symptoms. When animal premises are affected by VS, they are subject to a quarantine. The equine industry more broadly may incur economic losses due to interruptions of animal trade and transportation to shows, competitions, and other events. Equine owners, barn managers, and veterinarians can take proactive measures to reduce the risk of equines contracting VS. To identify appropriate risk management strategies, it helps to understand which biting insects are capable of transmitting the virus to animals, and to identify these insect vectors' preferred habitats and behaviors. We make this area of science more accessible to equine owners, barn managers, and veterinarians, by (1) translating the most relevant scientific information about biting insect vectors of VSV and (2) identifying practical management strategies that might reduce the risk of equines contracting VSV from infectious biting insects or from other equines already infected with VSV. We address transmission risk at four different spatial scales-the animal, the barn/shelter, the barnyard/premises, and the surrounding environment/neighborhood-noting that a multiscale and spatially collaborative strategy may be needed to reduce the risk of VS.


Assuntos
Doenças dos Bovinos , Doenças dos Cavalos , Doenças dos Suínos , Estomatite Vesicular , Vesiculovirus , Animais , Bovinos , Doenças dos Cavalos/prevenção & controle , Cavalos , Insetos Vetores , Suínos , Estados Unidos , Estomatite Vesicular/prevenção & controle , Vírus da Estomatite Vesicular Indiana
14.
Microbiol Resour Announc ; 9(16)2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32299883

RESUMO

We report the genome sequences of seven foot-and-mouth disease (FMD) virus (FMDV) isolates collected in India between 1997 and 2009. The strains represented four sublineages within the O/ME-SA/Ind2001 lineage. These viruses provide insights into FMDV diversity and evolution in India and may influence future control measures, including vaccine selections.

15.
Pathogens ; 9(2)2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32079312

RESUMO

Inactivated whole-virus vaccines are widely used for the control of foot-and-mouth disease (FMD). Their production requires the growth of large quantities of virulent FMD virus in biocontainment facilities, which is expensive and carries the risk of an inadvertent release of virus. Attenuated recombinant viruses lacking the leader protease coding region have been proposed as a safer alternative for the production of inactivated FMD vaccines (Uddowla et al., 2012, J Virol 86:11675-85). In addition to the leader deletion, the marker vaccine virus FMDV LL3BPVKV3DYR A24 encodes amino acid substitutions in the viral proteins 3B and 3D that allow the differentiation of infected from vaccinated animals and has been previously shown to be effective in cattle and pigs. In the present study, two groups of six pigs each were inoculated with live FMDV LL3BPVKV3DYR A24 virus either intradermally into the heel bulb (IDHB) or by intra-oropharyngeal (IOP) deposition. The animals were observed for 3 or 5 days after inoculation, respectively. Serum, oral and nasal swabs were collected daily and a thorough postmortem examination with tissue collection was performed at the end of the experiment. None of the animals had any signs of disease or virus shedding. Virus was reisolated from only one serum sample (IDHB group, sample taken on day 1) and one piece of heel bulb skin from the inoculation site of another animal (IDHB group, necropsy on day 3), confirming that FMDV LL3BPVKV3DYR A24 is highly attenuated in pigs.

16.
Vet Immunol Immunopathol ; 220: 109990, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31855743

RESUMO

In our previous transcriptomic studies using DNA microarray analysis, a probe designed from an unknown expressed sequence tag (EST) showed significant differential gene expression in the pharyngeal epithelia. The objectives of this study are to annotate the gene sequence and compare the gene transcription levels among different bovine tissues based on our published microarray data. The gene transcribing the EST contains a 90-amino-acid protein sequence. The results of bioinformatic analyses using comparative genetics, multiple sequence alignments, phylogenetic analysis and promoter sequence analysis indicated that this gene is a novel ELR+ CXCL gene orthologous to mouse CXCL15. The gene is highly conserved in ruminants and exists in many other mammals but not in chickens, primates or pigs. Phylogenetic analysis and gene structures showed that CXCL15 is closer to CXCL8 than to other ELR+ CXCLs. Our microarray data show that bovine CXCL15 expression was higher in laser capture micro-dissected bovine pharyngeal epithelia than in the whole pharyngeal tissues, which agrees with the expression in mice. However, unlike the high expression in the mouse lung, our results showed that the bovine nasal turbinate, dorsal nasopharynx, dorsal soft palate and tongue expressed higher levels of CXCL15 than the lung and skins. Promoter analysis showed that ruminants have more immune-related transcription factor binding sites in the proximal promoters of CXCL15 than mouse. CXCL15 has previously only been reported in mice and has neutrophil chemotactic activity. Given the critical roles of neutrophils in innate immunity, this study provides useful information for further characterization of bovine CXCL15.


Assuntos
Quimiocinas CXC/genética , Quimiocinas CXC/imunologia , Família Multigênica , Sequência de Aminoácidos , Animais , Bovinos , Biologia Computacional , Genômica , Imunidade Inata , Interleucina-8/genética , Mamíferos , Camundongos , Análise em Microsséries , Filogenia , Suínos
17.
Prev Vet Med ; 171: 104766, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541845

RESUMO

Foot-and-mouth disease virus (FMDV) has a substantial impact on cattle populations in Uganda, causing short- and long-term production losses and hampering local and international trade. Although FMDV has persisted in Uganda for at least 60 years, its epidemiology there and in other endemic settings remains poorly understood. Here, we utilized a large-scale cross-sectional study of cattle to elucidate the dynamics of FMDV spread in Uganda. Sera samples (n = 14,439) from 211 herds were analyzed for non-structural protein reactivity, an indication of past FMDV exposure. Serological results were used to determine spatial patterns, and a Bayesian multivariable logistic regression mixed model was used to identify risk factors for FMDV infection. Spatial clustering of the disease was evident, with higher risk demonstrated near international borders. Additionally, high cattle density, low annual rainfall, and pastoralism were associated with increased likelihood of FMD seropositivity. These results provide insights into the complex epidemiology of FMDV in Uganda and will help inform refined control strategies in Uganda and other FMDV-endemic settings.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Febre Aftosa/epidemiologia , Animais , Teorema de Bayes , Bovinos , Doenças dos Bovinos/sangue , Estudos Transversais , Febre Aftosa/sangue , Vírus da Febre Aftosa/isolamento & purificação , Fatores de Risco , Análise Espacial , Uganda/epidemiologia
18.
Microbiol Resour Announc ; 8(25)2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221649

RESUMO

We report the full-genome sequence of a New Jersey vesiculovirus strain, commonly referred to as vesicular stomatitis New Jersey virus (VSNJV), obtained from an epithelial lesion of a naturally infected cow in Chiapas, Mexico. This genome is a representative from the zone of endemicity in Mexico, a region of high genetic diversity.

19.
PLoS One ; 14(6): e0214832, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31226113

RESUMO

The role of foot-and-mouth disease virus (FMDV) persistently infected ruminants in initiating new outbreaks remains controversial, and the perceived threat posed by such animals hinders international trade in FMD-endemic countries. In this study we report longitudinal analyses of genetic and antigenic variations of FMDV serotype O/ME-SA/Ind2001d sublineage during naturally occurring, persistent infection in cattle and buffalo at an organised dairy farm in India. The proportion of animals from which FMDV RNA was recovered was not significantly different between convalescent (post-clinical) and sub-clinically infected animals or between cattle and buffalo across the sampling period. However, infectious virus was isolated from a higher proportion of buffalo samples and for a longer duration compared to cattle. Analysis of the P1 sequences from recovered viruses indicated fixation of mutations at the rate of 1.816 x 10-2substitution/site/year (s/s/y) (95% CI 1.362-2.31 x 10-2 s/s/y). However, the majority of point mutations were transitional substitutions. Within individual animals, the mean dN/dS (ω) value for the P1 region varied from 0.076 to 0.357, suggesting the selection pressure acting on viral genomes differed substantially across individual animals. Statistical parsimony analysis indicated that all of the virus isolates from carrier animals originated from the outbreak virus. The antigenic relationship value as determined by 2D-VNT assay revealed fluctuation of antigenic variants within and between carrier animals during the carrier state which suggested that some carrier viruses had diverged substantially from the protection provided by the vaccine strain. This study contributes to understanding the extent of within-host and within-herd evolution that occurs during the carrier state of FMDV.


Assuntos
Antígenos Virais/genética , Vírus da Febre Aftosa/imunologia , Febre Aftosa/genética , Animais , Variação Antigênica , Búfalos , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/virologia , Febre Aftosa/imunologia , Vírus da Febre Aftosa/genética , Predisposição Genética para Doença , Estudos Longitudinais , Mutação Puntual , RNA Viral/genética
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