scholarly journals Global emergence and evolutionary dynamics of bluetongue virus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Moh A. Alkhamis ◽  
Cecilia Aguilar-Vega ◽  
Nicholas M. Fountain-Jones ◽  
Kai Lin ◽  
Andres M. Perez ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Evolutionary Dynamics ◽  
Transmission Dynamics ◽  
Intervention Programs ◽  
Economic Losses ◽  
Molecular Surveillance ◽  
China And India ◽  
Evolutionary Epidemiology ◽  
Livestock Trade

AbstractBluetongue virus (BTV) epidemics are responsible for worldwide economic losses of up to US$ 3 billion. Understanding the global evolutionary epidemiology of BTV is critical in designing intervention programs. Here we employed phylodynamic models to quantify the evolutionary characteristics, spatiotemporal origins, and multi-host transmission dynamics of BTV across the globe. We inferred that goats are the ancestral hosts for BTV but are less likely to be important for cross-species transmission, sheep and cattle continue to be important for the transmission and maintenance of infection between other species. Our models pointed to China and India, countries with the highest population of goats, as the likely ancestral country for BTV emergence and dispersal worldwide over 1000 years ago. However, the increased diversification and dispersal of BTV coincided with the initiation of transcontinental livestock trade after the 1850s. Our analysis uncovered important epidemiological aspects of BTV that may guide future molecular surveillance of BTV.

scholarly journals Molecular Differentiation of Mycoplasma gallisepticum Outbreaks: A Last Decade Study on Italian Farms Using GTS and MLST

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 665
Author(s):  
Andrea Matucci ◽  
Elisabetta Stefani ◽  
Michele Gastaldelli ◽  
Ilenia Rossi ◽  
Gelinda De Grandi ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Evolutionary Dynamics ◽  
Housekeeping Genes ◽  
Mycoplasma Gallisepticum ◽  
Economic Losses ◽  
Strain Identification ◽  
Molecular Differentiation ◽  
Typing Methods ◽  
Infection Monitoring ◽  
Monitoring Activity

Mycoplasma gallisepticum (MG) infects many avian species and leads to significant economic losses in the poultry industry. Transmission of this pathogen occurs both horizontally and vertically, and strategies to avoid the spread of MG rely on vaccination and the application of biosecurity measures to maintain breeder groups as pathogen-free. Two live attenuated MG vaccine strains are licensed in Italy: 6/85 and ts-11. After their introduction, the implementation of adequate genotyping tools became necessary to distinguish between field and vaccine strains and to guarantee proper infection monitoring activity. In this study, 40 Italian MG isolates collected between 2010–2019 from both vaccinated and unvaccinated farms were genotyped using gene-targeted sequencing (GTS) of the cythadesin gene mgc2 and multilocus sequence typing (MLST) based on six housekeeping genes. The discriminatory power of GTS typing ensures 6/85-like strain identification, but the technique does not allow the identification ts-11 strains; conversely, MLST differentiates both vaccine strains, describing more detailed interrelation structures. Our study describes MG genetic scenario within a mixed farming context. In conclusion, the use of adequate typing methods is essential to understand the evolutionary dynamics of MG strains in a particular area and to conduct epidemiological investigations in the avian population.

scholarly journals Genomic Epidemiology of Salmonid Alphavirus in Norwegian Aquaculture Reveals Recent Subtype-2 Transmission Dynamics and Novel Subtype-3 Lineages

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2549
Author(s):  
Daniel J. Macqueen ◽  
Oliver Eve ◽  
Manu Kumar Gundappa ◽  
Rose Ruiz Daniels ◽  
Michael D. Gallagher ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Viral Evolution ◽  
Viral Disease ◽  
Transmission Dynamics ◽  
Disease Spread ◽  
Economic Losses ◽  
Fish Welfare ◽  
Major Barrier ◽  
Genomic Epidemiology ◽  
Northern Latitudes

Viral disease poses a major barrier to sustainable aquaculture, with outbreaks causing large economic losses and growing concerns for fish welfare. Genomic epidemiology can support disease control by providing rapid inferences on viral evolution and disease transmission. In this study, genomic epidemiology was used to investigate salmonid alphavirus (SAV), the causative agent of pancreas disease (PD) in Atlantic salmon. Our aim was to reconstruct SAV subtype-2 (SAV2) diversity and transmission dynamics in recent Norwegian aquaculture, including the origin of SAV2 in regions where this subtype is not tolerated under current legislation. Using nanopore sequencing, we captured ~90% of the SAV2 genome for n = 68 field isolates from 10 aquaculture production regions sampled between 2018 and 2020. Using time-calibrated phylogenetics, we infer that, following its introduction to Norway around 2010, SAV2 split into two clades (SAV2a and 2b) around 2013. While co-present at the same sites near the boundary of Møre og Romsdal and Trøndelag, SAV2a and 2b were generally detected in non-overlapping locations at more Southern and Northern latitudes, respectively. We provide evidence for recent SAV2 transmission over large distances, revealing a strong connection between Møre og Romsdal and SAV2 detected in 2019/20 in Rogaland. We also demonstrate separate introductions of SAV2a and 2b outside the SAV2 zone in Sognefjorden (Vestland), connected to samples from Møre og Romsdal and Trøndelag, respectively, and a likely 100 km Northward transmission of SAV2b within Trøndelag. Finally, we recovered genomes of SAV2a and SAV3 co-infecting single fish in Rogaland, involving novel SAV3 lineages that diverged from previously characterized strains >25 years ago. Overall, this study demonstrates useful applications of genomic epidemiology for tracking viral disease spread in aquaculture.

scholarly journals Seroprevalence and intercurrence of reproductive pathogens in cattle from family farms in North of Minas Gerais, Brazil

2020 ◽  
Vol 41 (1) ◽  
pp. 145
Author(s):  
Dionei Joaquim Haas ◽  
Jonata de Melo Barbieri ◽  
Ermilton Junio Pereira de Freitas ◽  
Mayra da Silva Oliveira ◽  
Bernardo Rodrigues Porto ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Associated Factors ◽  
Minas Gerais ◽  
Control Measures ◽  
Economic Losses ◽  
Family Farms ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Leptospira Spp ◽  
Viral Diarrhea Virus

The aims of the present study were: to estimate the seroprevalence of Bluetongue vírus (BTV), bovine alphaherpesvirus 1 (BoHV-1), bovine viral diarrhea virus (BVDV), Brucella abortus and Leptospira spp. in cattle from family farms in North of Minas Gerais; to determine the intercurrence and association among these pathogens; and to assess the possible associated factors to seropositive herds and animals. For this, 476 cows from 46 farms were sampled and evaluated serologically. The seroprevalence in herds and cattle was, respectively, for BTV 100% and 52.0%, for BoHV-1 95.7% and 48.6%, for BVDV 78.3% and 46.1%, for Leptospira spp. 76.1% and 29.1%, and for B. abortus was 0% in herd and cattle. More than 65% of the herds was simultaneously seropositive for BTV, BoHV-1, BVDV and Leptospira spp. Seropositivity for BoHV-1, Leptospira spp. serovar Autumnalis and serovar Hardjoprajitno were associated with abortion, whereas seropositivity for BVDV was associated with BoHV-1. Moreover, association among seropositivity for BVDV, BoHV-1 and Leptospira spp. was also observed. In conclusion, BTV, BoHV-1, BVDV and Leptospira spp. are highly seroprevalent and occurred simultaneously in cattle from family farms in Minas Gerais, indicating the need for the implementation of control measures to avoid economic losses related to these diseases.

scholarly journals Identification of a BTV-Strain-Specific Single Gene That Increases Culicoides Vector Infection Rate

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1781
Author(s):  
Honorata M. Ropiak ◽  
Simon King ◽  
Marc Guimerà Busquets ◽  
Kerry Newbrook ◽  
Gillian D. Pullinger ◽  
...  
Keyword(s):  
Infection Rate ◽  
Bluetongue Virus ◽  
Genetic Basis ◽  
Single Gene ◽  
Field Strain ◽  
Economic Losses ◽  
Amino Acid Substitutions ◽  
Low Levels ◽  
Culicoides Vectors ◽  
Virus Strains

Since the 2000s, the distribution of bluetongue virus (BTV) has changed, leading to numerous epidemics and economic losses in Europe. Previously, we found a BTV-4 field strain with a higher infection rate of a Culicoides vector than a BTV-1 field strain has. We reverse-engineered parental BTV-1 and BTV-4 strains and created BTV-1/BTV-4 reassortants to elucidate the influence of individual BTV segments on BTV replication in both C. sonorensis midges and in KC cells. Substitution of segment 2 (Seg-2) with Seg-2 from the rBTV-4 significantly increased vector infection rate in reassortant BTV-14S2 (30.4%) in comparison to reverse-engineered rBTV-1 (1.0%). Replacement of Seg-2, Seg-6 and Seg-7 with those from rBTV-1 in reassortant BTV-41S2S6S7 (2.9%) decreased vector infection rate in comparison to rBTV-4 (30.2%). However, triple-reassorted BTV-14S2S6S7 only replicated to comparatively low levels (3.0%), despite containing Seg-2, Seg-6 and Seg-7 from rBTV-4, indicating that vector infection rate is influenced by interactions of multiple segments and/or host-mediated amino acid substitutions within segments. Overall, these results demonstrated that we could utilize reverse-engineered viruses to identify the genetic basis influencing BTV replication within Culicoides vectors. However, BTV replication dynamics in KC cells were not suitable for predicting the replication ability of these virus strains in Culicoides midges.

scholarly journals Plasmid co-infection: linking biological mechanisms to ecological and evolutionary dynamics

2021 ◽  
Vol 377 (1842) ◽  
Author(s):  
Claudia Igler ◽  
Jana S. Huisman ◽  
Berit Siedentop ◽  
Sebastian Bonhoeffer ◽  
Sonja Lehtinen
Keyword(s):  
Evolutionary Dynamics ◽  
Theoretical Work ◽  
Plasmid Copy Number ◽  
Biological Processes ◽  
Ecological Interactions ◽  
Biological Mechanisms ◽  
Plasmid Copy ◽  
Host Interactions ◽  
Evolutionary Epidemiology ◽  
The Impact

As infectious agents of bacteria and vehicles of horizontal gene transfer, plasmids play a key role in bacterial ecology and evolution. Plasmid dynamics are shaped not only by plasmid–host interactions but also by ecological interactions between plasmid variants. These interactions are complex: plasmids can co-infect the same cell and the consequences for the co-resident plasmid can be either beneficial or detrimental. Many of the biological processes that govern plasmid co-infection—from systems that exclude infection by other plasmids to interactions in the regulation of plasmid copy number—are well characterized at a mechanistic level. Modelling plays a central role in translating such mechanistic insights into predictions about plasmid dynamics and the impact of these dynamics on bacterial evolution. Theoretical work in evolutionary epidemiology has shown that formulating models of co-infection is not trivial, as some modelling choices can introduce unintended ecological assumptions. Here, we review how the biological processes that govern co-infection can be represented in a mathematical model, discuss potential modelling pitfalls, and analyse this model to provide general insights into how co-infection impacts ecological and evolutionary outcomes. In particular, we demonstrate how beneficial and detrimental effects of co-infection give rise to frequency-dependent selection on plasmid variants. This article is part of the theme issue ‘The secret lives of microbial mobile genetic elements’.

scholarly journals Bluetongue in Europe – the risk of animal import from restricted zones

2019 ◽  
Vol 75 (05) ◽  
pp. 6254-2019
Author(s):  
ANNA ORŁOWSKA ◽  
MARCIN SMRECZAK ◽  
JERZY ROLA
Keyword(s):  
Genetic Diversity ◽  
20Th Century ◽  
Bluetongue Virus ◽  
Viral Disease ◽  
Economic Losses ◽  
High Genetic Diversity ◽  
Key Factor ◽  
Vector Borne ◽  
Sentinel Animals ◽  
Free Status

Bluetongue (BT) is a vector-borne viral disease effecting ruminants caused by bluetongue virus (BTV), transmitted mainly by bites from midges of the genus Culicoides. Since the end of 20th century, BTV is endemic in several European countries and the disease is caused mainly by BTV-8 and BTV-4 infections. Bluetongue virus is characterized by high genetic diversity. To date, over 29 BTV serotypes have been documented, including recently discovered atypical serotypes BTV (25–27). The disease has a high economic impact as it causes economic losses due to animal mortality, reduced productivity and restrictions on the movement of animals. Several reports and numerous observations indicate the contribution of animal movements to the spread of BTV infections. Thus, bluetongue surveillance that includes testing of sentinel animals as well as virological testing of animals susceptible to BTV infection imported from restricted zones due to the presence of BTV is a key factor in maintaining a BT-free status

scholarly journals Vaccination With Recombinant Adenoviruses Expressing the Bluetongue Virus Subunits VP7 and VP2 Provides Protection Against Heterologous Virus Challenge

2021 ◽  
Vol 8 ◽  
Author(s):  
José Manuel Rojas ◽  
Diego Barba-Moreno ◽  
Miguel Avia ◽  
Noemí Sevilla ◽  
Verónica Martín
Keyword(s):  
T Cell ◽  
Bluetongue Virus ◽  
Neutralizing Antibodies ◽  
Inner Core ◽  
Core Protein ◽  
T Cell Responses ◽  
Outer Core ◽  
Economic Losses ◽  
Virus Challenge ◽  
Cell Responses

Bluetongue virus (BTV) is the causative agent of a disease that affects domestic and wild ruminants and leads to critical economic losses. BTV is an arbovirus from the Reoviridae family that is typically transmitted by the bite of infected Culicoides midges. BTV possesses multiple serotypes (up to 28 have been described), and immunity to one serotype offers little cross-protection to other serotypes. The design of vaccines that provide protection across multiple serotypes is therefore highly desirable to control this disease. We previously reported that a recombinant replication-defective human adenovirus serotype 5 (Ad5) that expresses the VP7 inner core protein of BTV serotype 8 (Ad5VP7-8) induced T-cell responses and provided protection. In the present work, we evaluated as BTV vaccine the combination of Ad5VP7-8 with another recombinant Ad5 that expresses the outer core protein VP2 from BTV-1 (Ad5VP2-1). The combination of Ad5VP2-1 and Ad5VP7-8 protected against homologous BTV challenge (BTV-1 and BTV-8) and partially against heterologous BTV-4 in a murine model. Cross-reactive anti-BTV immunoglobulin G (IgG) were detected in immunized animals, but no significant titers of neutralizing antibodies were elicited. The Ad5VP7-8 immunization induced T-cell responses that recognized all three serotypes tested in this study and primed cytotoxic T lymphocytes specific for VP7. This study further confirms that targeting antigenic determinant shared by several BTV serotypes using cellular immunity could help develop multiserotype BTV vaccines.

scholarly journals Genomic and Pathogenic Characteristics of Virulent Newcastle Disease Virus Isolated from Chicken in Live Bird Markets and Backyard Flocks in Kenya

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Irene N. Ogali ◽  
Paul O. Okumu ◽  
Erick O. Mungube ◽  
Jacqueline K. Lichoti ◽  
Stephen Ogada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Newcastle Disease ◽  
Evolutionary Dynamics ◽  
Economic Losses ◽  
Lymphoid Tissues ◽  
Genome Sequences ◽  
African Countries ◽  
Functional Sites ◽  
Virulent Newcastle Disease Virus ◽  
Genotype V

Newcastle disease (ND) causes significant economic losses in the poultry industry in developing countries. In Kenya, despite rampant annual ND outbreaks, implementation of control strategies is hampered by a lack of adequate knowledge on the circulating and outbreak causing-NDV strains. This study reports the first complete genome sequences of NDV from backyard chicken in Kenya. The results showed that all three isolates are virulent, as assessed by the mean death time (MDT) and intracerebral pathogenicity index (ICPI) in specific antibody negative (SAN) embryonated eggs and 10-day-old chickens, respectively. Also, the polybasic amino acid sequence at the fusion-protein cleavage site had the motif 112RRQKRFV118. Histopathological findings in four-week-old SPF chicken challenged with the NDV isolates KE001, KE0811, and KE0698 showed multiple organ involvement at five days after infection with severe effects seen in lymphoid tissues and blood vessels. Analysis of genome sequences obtained from the three isolates showed that they were 15192 base pair (bp) in length and had genomic features consistent with other NDV strains, the functional sites within the coding sequence being highly conserved in the sequence of the three isolates. Amino acid residues and substitutions in the structural proteins of the three isolates were similar to the newly isolated Tanzanian NDV strain (Mbeya/MT15). A similarity matrix showed a high similarity of the isolates to NDV strains of class II genotype V (89–90%) and subgenotype Vd (95–97%). Phylogenetic analysis confirmed that the three isolates are closely related to NDV genotype V strains but form a distinct cluster together with NDV strains from the East African countries of Uganda and Tanzania to form the newly characterized subgenotype Vd. Our study provides the first description of the genomic and pathological characteristics of NDV of subgenotype Vd and lays a baseline in understanding the evolutionary dynamics of NDV and, in particular, Genotype V. This information will be useful in the development of specific markers for detection of viruses of genotype V and generation of genotype matched vaccines.

scholarly journals Insights into Genomic Epidemiology, Evolution, and Transmission Dynamics of Genotype VII of Class II Newcastle Disease Virus in China

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 837
Author(s):  
Bin Xiang ◽  
Libin Chen ◽  
Juncheng Cai ◽  
Jianpeng Liang ◽  
Qiuyan Lin ◽  
...  
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Evolutionary Dynamics ◽  
Genotypic Diversity ◽  
Class Ii ◽  
Transmission Dynamics ◽  
Clinical Samples ◽  
Genomic Epidemiology ◽  
Genotype Vii

Newcastle disease virus (NDV) is distributed worldwide and has caused significant losses to the poultry industry. Almost all virulent NDV strains belong to class II, among which genotype VII is the predominant genotype in China. However, the molecular evolution and phylodynamics of class II genotype VII NDV strains in China remained largely unknown. In this study, we identified 13 virulent NDV including 11 genotype VII strains and 2 genotype IX strains, from clinical samples during 1997 to 2019. Combined NDV sequences submitted to GenBank, we investigate evolution, and transmission dynamics of class II NDVs in China, especially genotype VII strains. Our results revealed that East and South China have the most genotypic diversity of class II NDV, and East China might be the origin of genotype VII NDVs in China. In addition, genotype VII NDVs in China are presumably transmitted by chickens, as the virus was most prevalent in chickens. Furthermore, codon usage analysis revealed that the F genes of genotype VII NDVs have stronger adaptation in chickens, and six amino acids in this gene are found under positive selection via selection model analysis. Collectively, our results revealed the genetic diversity and evolutionary dynamics of genotype VII NDVs in China, providing important insights into the epidemiology of these viruses in China.

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