Analysis of clinical samples for early detection of classical swine fever during infection with low, moderate, and highly virulent strains in relation to the onset of clinical signs

2012 ◽  
Vol 179 (1) ◽  
pp. 108-115 ◽  
Author(s):  
Brenda C. Donahue ◽  
Heather M. Petrowski ◽  
Karin Melkonian ◽  
Gordon B. Ward ◽  
Gregory A. Mayr ◽  
...  
Keyword(s):  
Early Detection ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Clinical Samples ◽  
Virulent Strains ◽  
Highly Virulent

scholarly journals Analysis of Virus Population Profiles within Pigs Infected with Virulent Classical Swine Fever Viruses: Evidence for Bottlenecks in Transmission but Absence of Tissue-Specific Virus Variants

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Camille Melissa Johnston ◽  
Ulrik Fahnøe ◽  
Louise Lohse ◽  
Jens Bukh ◽  
Graham J. Belsham ◽  
...  
Keyword(s):  
Classical Swine Fever Virus ◽  
Population Change ◽  
Virulent Strain ◽  
Severe Disease ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Host Cells ◽  
Virus Population ◽  
Highly Virulent

ABSTRACT Classical swine fever virus (CSFV) contains a specific motif within the E2 glycoprotein that differs between strains of different virulence. In the highly virulent CSFV strain Koslov, this motif comprises residues S763/L764 in the polyprotein. However, L763/P764 represent the predominant alleles in published CSFV genomes. In this study, changes were introduced into the CSFV strain Koslov (here called vKos_SL) to generate modified CSFVs with substitutions at residues 763 and/or 764 (vKos_LL, vKos_SP, and vKos_LP). The properties of these mutant viruses, in comparison to those of vKos_SL, were determined in pigs. Each of the viruses was virulent and induced typical clinical signs of CSF, but the vKos_LP strain produced them significantly earlier. Full-length CSFV cDNA amplicons (12.3 kb) derived from sera of infected pigs were deep sequenced and cloned to reveal the individual haplotypes that contributed to the single-nucleotide polymorphism (SNP) profiles observed in the virus population. The SNP profiles for vKos_SL and vKos_LL displayed low-level heterogeneity across the entire genome, whereas vKos_SP and vKos_LP displayed limited diversity with a few high-frequency SNPs. This indicated that vKos_SL and vKos_LL exhibited a higher level of fitness in the host and more stability at the consensus level, whereas several consensus changes were observed in the vKos_SP and vKos_LP sequences, pointing to adaptation. For each virus, only a subset of the variants present within the virus inoculums were maintained in the infected pigs. No clear tissue-dependent quasispecies differentiation occurred within inoculated pigs; however, clear evidence for transmission bottlenecks to contact animals was observed, with subsequent loss of sequence diversity. IMPORTANCE The surface-exposed E2 protein of classical swine fever virus is required for its interaction with host cells. A short motif within this protein varies between strains of different virulence. The importance of two particular amino acid residues in determining the properties of a highly virulent strain of the virus has been analyzed. Each of the different viruses tested proved highly virulent, but one of them produced earlier, but not more severe, disease. By analyzing the virus genomes present within infected pigs, it was found that the viruses which replicated within inoculated animals were only a subset of those within the virus inoculum. Furthermore, following contact transmission, it was shown that a very restricted set of viruses had transferred between animals. There were no significant differences in the virus populations present in various tissues of the infected animals. These results indicate mechanisms of virus population change during transmission between animals.

scholarly journals Assessing the Protective Dose of a Candidate DIVA Vaccine against Classical Swine Fever

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 483
Author(s):  
Tinka Jelsma ◽  
Jacob Post ◽  
Erwin van den Born ◽  
Ruud Segers ◽  
Jeroen Kortekaas
Keyword(s):  
Infectious Virus ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Wild Type ◽  
Challenge Virus ◽  
Virus Particles ◽  
Virus Rna ◽  
Single Vaccination ◽  
Highly Virulent ◽  
Insight Into

Classical swine fever is a highly contagious and deadly disease in swine. The disease can be controlled effectively by vaccination with an attenuated virus known as the “Chinese” (C)-strain. A single vaccination with the C-strain provides complete protection against highly virulent isolates within days after vaccination, making it one of the most efficacious veterinary vaccines ever developed. A disadvantage of the C-strain is that vaccinated animals cannot be serologically differentiated from animals that are infected with wild-type Classical swine fever virus. Previously, a C-strain-based vaccine with a stable deletion in the E2 structural glycoprotein was developed, which allows for differentiation between infected and vaccinated animals (DIVA). The resulting vaccine, which we named C-DIVA, is compatible with a commercial E2 ELISA, modified to render it suitable as a DIVA test. In the present work, three groups of eight piglets were vaccinated with escalating doses of the C-DIVA vaccine and challenged two weeks after vaccination. One group of four unvaccinated piglets served as controls. Piglets were monitored for clinical signs until three weeks after challenge and blood samples were collected to monitor viremia, leukocyte and thrombocyte levels, and antibody responses. The presence of challenge virus RNA in oropharyngeal swabs was investigated to first gain insight into the potential of C-DIVA to prevent shedding. The results demonstrate that a single vaccination with 70 infectious virus particles of C-DIVA protects pigs from the highly virulent Brescia strain.

Classical swine fever in pigs: recent developments and future perspectives

2014 ◽  
Vol 15 (1) ◽  
pp. 87-101 ◽  
Author(s):  
Vishal Chander ◽  
S. Nandi ◽  
C. Ravishankar ◽  
V. Upmanyu ◽  
Rishendra Verma
Keyword(s):  
Point Of Care ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Diagnostic Techniques ◽  
Effective Control ◽  
Clinical Samples ◽  
High Morbidity ◽  
Phylogenetic Groups ◽  
Control Programs ◽  
Different Strains

AbstractClassical swine fever (CSF) is one of the most devastating epizootic diseases of pigs, causing high morbidity and mortality worldwide. The diversity of clinical signs and similarity in disease manifestations to other diseases make CSF difficult to diagnose with certainty. The disease is further complicated by the presence of a number of different strains belonging to three phylogenetic groups. Advanced diagnostic techniques allow detection of antigens or antibodies in clinical samples, leading to implementation of proper and effective control programs. Polymerase chain reaction (PCR)-based methods, including portable real-time PCR, provide diagnosis in a few hours with precision and accuracy, even at the point of care. The disease is controlled by following a stamping out policy in countries where vaccination is not practiced, whereas immunization with live attenuated vaccines containing the ‘C’ strain is effectively used to control the disease in endemic countries. To overcome the problem of differentiation of infected from vaccinated animals, different types of marker vaccines, with variable degrees of efficacy, along with companion diagnostic assays have been developed and may be useful in controlling and even eradicating the disease in the foreseeable future. The present review aims to provide an overview and status of CSF as a whole with special reference to swine husbandry in India.

scholarly journals Classical swine fever: current situation in European countries and its potential danger for the greek pig industry

2018 ◽  
Vol 49 (4) ◽  
pp. 263
Author(s):  
S. C. KYRIAKIS (ΚΥΡΙΑΚΗΣ Σ.Κ.) ◽  
S. K. KRITAS (Σ.Κ. ΚΡΗΤΑΣ) ◽  
O. PAPADOPOULOS (ΠΑΠΑΔΟΠΟΥΛΟΣ Ο.) ◽  
I. MAVROMATIS (ΜΑΥΡΟΜΑΤΗΣ Ι.) ◽  
A. TSINAS (ΤΣΙΝΑΣ Α.)
Keyword(s):  
Review Paper ◽  
Preventive Measures ◽  
Classical Swine Fever ◽  
Viral Disease ◽  
General Information ◽  
European Countries ◽  
Potential Danger ◽  
Virulent Strains ◽  
Painful Experience ◽  
Highly Virulent

Classical swine fever is a highly contagious viral disease of substantial economical importance for the pig industry. Its clinical demonstration varies according to the virulence of the infecting strain, so that highly virulent strains cause severe acute disease, whilst strains of low virulence appear to cause only mild or even inapparent disease. Swine fever is α problem in many countries worldwide for years. In Greece, the latest case was reported during 1985. Nowdays, swine fever became once more "hot" due to its appearance in countries that were free of the disease for long periods (Holland, Spain, Italy etc). In this review paper, some general information necessary for the understanding and the prevention of the disease are presented, and the latest data of the recent epidemic in different European countries are retrieved. Finally, based on the recent "painful" experience of these countries, essential preventive measures for the greek pig industry are suggested.

How Molecular Epidemiology Can Affect Tuberculosis Control in the Middle East Countries: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 20 ◽  
Author(s):  
Mohammad Asgharzadeh ◽  
Jalil Rashedi ◽  
Behroz Mahdavi Poor ◽  
Hossein Samadi kafil ◽  
Hossein Moharram Zadeh ◽  
...  
Keyword(s):  
Middle East ◽  
Molecular Epidemiology ◽  
Average Rate ◽  
Meta Analysis ◽  
Close Monitoring ◽  
Drug Resistant ◽  
Middle East Countries ◽  
Virulent Strains ◽  
Recent Transmission ◽  
Highly Virulent

: Nowadays, due to the incidence of specific strains of Mycobacterium tuberculosis and also increase the rate of drug resistant-TB mortality rate has elevated by this disease. Identification of common strains in the region as well as sources of transmission are essential to control the disease that this has been possible by using molecular epidemiology. In this survey, studies which have been carried out based on spoligotyping method in Muslim Middle East countries were considered to determine their role in control of TB. All studies conducted from 2005 to June 2016 were considered systematically in three electronic data bases and finally, 23 studies were selected. The average rate of clustering was 84% and the rate of recent transmission was variable from 21.7% to 92.4%. Incidence of Beijing strains was been rising in the considered countries. In Iran and Saudi Arabia which are immigration and labour-hosting countries, respectively, rapid transmittable strains and drug resistant Beijings were higher than other considered countries. Considering the incidence of highly virulent strains, due to the increase of immigration and people infected with HIV, tuberculosis, especially drug resistant form, the lack of close monitoring in the future will be induce trouble.

Survival of classic swine fever virus in hams made from the meat of pigs vaccinated with the PAV-250 strain and unvaccinated pigs

2019 ◽  
Vol 10 (3) ◽  
pp. 536-551
Author(s):  
Heidi Amezcua Hempel ◽  
María Salud Rubio Lozano ◽  
Eliseo Manuel Hernández Baumgarten ◽  
Pablo Correa Girón † ◽  
Oscar Torres Ángeles ◽  
...  
Keyword(s):  
Reference Strain ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Direct Immunofluorescence ◽  
Biometric Analysis ◽  
Treatment Groups ◽  
Group A ◽  
Group B ◽  
Group D

The study was to determine the presence of Classical Swine Fever virus (CSFv), in the meat of vaccinated pigs with the PAV-250 strain and then challenged using the same strain. Five treatment groups were established (each with four pigs). Group A: Pigs thatwere fed with processed hams from negative animals; Group B: Pigs that were fed with processed hams from commercial pigs inoculated with the ALD (reference strain) (titre of 104.0/ml); Group C: Pigs fed with processed hams from pigs infected with the virulent ALD strain (titre of 102.5/ml); Group D: Pigs fed with processed hams from pigs vaccinated with the PAV-250 strain and challenged with the ALD strain (titre of 101.1/ml); and Group E: Pigs fed with processed hams from pigs vaccinated with two doses of the PAV-250 strain and challenged with the ALD strain (negative). Blood samples were taken at d 1, 5, 10, 15 and 20 for biometric analysis. Groups B, C and D manifested clinical signs of CSFv: 40 °C temperature, anorexia, paralysis, vomiting, diarrhea, tremor, hirsute hair and cyanosis. Pigs were slaughtered and necropsies performed to identify lesions in tissues. Results of direct immunofluorescence testing of tissues were positive and the virus was recovered. Under these study conditions, it was found that CSFv resisted the cooking method at 68 °C for 40 min in hams from unvaccinated pigs, and that the virus was able to transmit the disease to healthy unvaccinated pigs, whereas the hams from the vaccinated animals did not transmit the virus.

scholarly journals Challenge of Naïve and Vaccinated Pigs with a Vaccine-Derived Recombinant Porcine Reproductive and Respiratory Syndrome Virus 1 Strain (Horsens Strain)

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 417
Author(s):  
Lise K. Kvisgaard ◽  
Lars E. Larsen ◽  
Charlotte S. Kristensen ◽  
Frédéric Paboeuf ◽  
Patricia Renson ◽  
...  
Keyword(s):  
Viral Load ◽  
Experimental Model ◽  
Recombinant Strain ◽  
Clinical Signs ◽  
Growing Pigs ◽  
Respiratory Syndrome Virus ◽  
Almost All ◽  
Highly Virulent

In July 2019, a vaccine-derived recombinant Porcine reproductive and respiratory syndrome virus 1 strain (PRRSV-1) (Horsens strain) infected more than 40 Danish sow herds, resulting in severe losses. In the present study, the pathogenicity of the recombinant Horsens strain was assessed and compared to a reference PRRSV-1 strain using a well-characterized experimental model in young SPF pigs. Furthermore, the efficacies of three different PRRSV-1 MLV vaccines to protect pigs against challenge with the recombinant strain were assessed. Following challenge, the unvaccinated pigs challenged with the Horsens strain had significant increased viral load in serum compared to all other groups. No macroscopic changes were observed at necropsy, but tissue from the lungs and tonsils from almost all pigs were PRRSV-positive. The viral load in serum was lower in all vaccinated groups compared to the unvaccinated group challenged with the Horsens strain, and only small differences were seen among the vaccinated groups. The findings in the present study, combined with two other recent reports, indicate that this recombinant “Horsens” strain indeed is capable of inducing infection in growing pigs as well as in pregnant sows that is comparable to or even exceeding those induced by typical PRRSV-1, subtype 1 strains. However, absence of notable clinical signs and lack of significant macroscopic changes indicate that this strain is less virulent than previously characterized highly virulent PRRSV-1 strains.

scholarly journals Virus Adaptation Following Experimental Infection of Chickens with a Domestic Duck Low Pathogenic Avian Influenza Isolate from the 2017 USA H7N9 Outbreak Identifies Polymorphic Mutations in Multiple Gene Segments

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1166
Author(s):  
Klaudia Chrzastek ◽  
Karen Segovia ◽  
Mia Torchetti ◽  
Mary Lee Killian ◽  
Mary Pantin-Jackwood ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Experimental Infection ◽  
Clinical Signs ◽  
Interspecies Transmission ◽  
Clinical Samples ◽  
Domestic Duck ◽  
Receptor Binding Site ◽  
Synonymous Mutations ◽  
Field Samples ◽  
Virus Adaptation

In March 2017, highly pathogenic (HP) and low pathogenic (LP) avian influenza virus (AIV) subtype H7N9 were detected from poultry farms and backyard birds in several states in the southeast United States. Because interspecies transmission is a known mechanism for evolution of AIVs, we sought to characterize infection and transmission of a domestic duck-origin H7N9 LPAIV in chickens and genetically compare the viruses replicating in the chickens to the original H7N9 clinical field samples used as inoculum. The results of the experimental infection demonstrated virus replication and transmission in chickens, with overt clinical signs of disease and shedding through both oral and cloacal routes. Unexpectedly, higher levels of virus shedding were observed in some cloacal swabs. Next generation sequencing (NGS) analysis identified numerous non-synonymous mutations at the consensus level in the polymerase genes (i.e., PA, PB1, and PB2) and the hemagglutinin (HA) receptor binding site in viruses recovered from chickens, indicating possible virus adaptation in the new host. For comparison, NGS analysis of clinical samples obtained from duck specimen collected during the outbreak indicated three polymorphic sides in the M1 segment and a minor population of viruses carrying the D139N (21.4%) substitution in the NS1 segment. Interestingly, at consensus level, A/duck/Alabama (H7N9) had isoleucine at position 105 in NP protein, similar to HPAIV (H7N9) but not to LPAIV (H7N9) isolated from the same 2017 influenza outbreak in the US. Taken together, this work demonstrates that the H7N9 viruses could readily jump between avian species, which may have contributed to the evolution of the virus and its spread in the region.

scholarly journals BARD1 Autoantibody Blood Test for Early Detection of Ovarian Cancer

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 969
Author(s):  
Maxim Pilyugin ◽  
Magda Ratasjka ◽  
Maciej Stukan ◽  
Nicole Concin ◽  
Robert Zeillinger ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Early Detection ◽  
Blood Test ◽  
Menopausal Status ◽  
Clinical Samples ◽  
Average Risk ◽  
Healthy Controls ◽  
Cancer Antigen 125 ◽  
Cancer Syndrome ◽  
Ovarian Cancer Screening

Background: Ovarian cancer (OC) is the most lethal gynaecological cancer. It is often diagnosed at an advanced stage with poor chances for successful treatment. An accurate blood test for the early detection of OC could reduce the mortality of this disease. Methods: Autoantibody reactivity to 20 epitopes of BARD1 and concentration of cancer antigen 125 (CA125) were assessed in 480 serum samples of OC patients and healthy controls. Autoantibody reactivity and CA125 were also tested for 261 plasma samples of OC with or without mutations in BRCA1/2, BARD1, or other predisposing genes, and healthy controls. Lasso statistic regression was applied to measurements to develop an algorithm for discrimination between OC and controls. Findings and interpretation: Measurement of autoantibody binding to a number of BARD1 epitopes combined with CA125 could distinguish OC from healthy controls with high accuracy. This BARD1-CA125 test was more accurate than measurements of BARD1 autoantibody or CA125 alone for all OC stages and menopausal status. A BARD1-CA125-based test is expected to work equally well for average-risk women and high-risk women with hereditary breast and ovarian cancer syndrome (HBOC). Although these results are promising, further data on well-characterised clinical samples shall be used to confirm the potential of the BARD1-CA125 test for ovarian cancer screening.

Sign in / Sign up

Export Citation Format

Share Document