Modified live vaccine strains of porcine reproductive and respiratory syndrome virus cause immune system dysregulation similar to wild strains.

Introduction: Porcine reproductive and respiratory syndrome virus (PRRSV) emerged about 30 years ago and continues to cause major economic losses in the pork industry. The lack of effective modified live vaccines (MLV) allows the pandemic to continue.

Background And Objective: We have previously shown that wild strains of PRRSV affect the nascent T cell repertoire in the thymus, deplete T cell clones recognizing viral epitopes essential for neutralization, while triggering a chronic, robust, but ineffective antibody response.

The mechanism of immune dysregulation caused by porcine reproductive and respiratory syndrome virus (PRRSV).

PRRSV is capable of evading the effective immune response, thus persisting in piglets and throughout the swine herd. We show here that PRRSV invades the thymus and causes depletion of T-cell precursors and alteration of the TCR repertoire. Developing thymocytes are affected during negative selection when they transit from the triple-negative to triple-positive stages at the corticomedullary junction just before entering the medulla.

First detection of Lake Sinai virus in the Czech Republic: a potential member of a new species.

Lake Sinai virus (LSV) is one of over 20 honey bee viruses. Variants of LSV have been classified as members of two officially recognised species, Lake Sinai virus 1 and Lake Sinai virus 2. However, there are currently a limited number of whole-genome sequences, and the genetic variability of the virus indicates that additional species may need to be established.

Experimental Evidence of the Long-Term Survival of Infective African Swine Fever Virus Strain Ba71V in Soil under Different Conditions.

The survival of African swine fever virus (ASFV) on different matrices and its infectivity in wild as well as domestic swine is still a matter of interest. ASFV is resistant to environmental effects; this fact is enhanced by the presence of organic material. Therefore, the aim of this work was to determine the ability of laboratory ASFV to survive in soil at different temperatures (4 and 22 °C) and with and without the presence of blood using culture procedures.

Whole-genome sequence of a reassortant G9P[4] rotavirus A strain from two children in the Czech Republic.

An unusual reassortant rotavirus A (RVA) strain was isolated during RVA surveillance in two previously hospitalized children in 2018. G/P typing revealed uncommon G9P[4] genotypes, so the strains were further characterized by Illumina next-generation sequencing. Whole-genome typing showed that the two strains had a DS-1-like backbone except for NSP2: G9-P[4]-I2-R2-C2-M2-A2-N1-T2-E2-H2.

[Our experience in laboratory diagnosis of rotaviruses].

Objective: Group A rotavirus (RVA) is one of leading causes of gastroenteritis in children under five years of age and is also an important nosocomial pathogen. In Europe, the most prevalent genotypes of RVA are G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]. Severe dehydration is the most important complication of RVA gastroenteritis.

Emergence of Rare Bovine-Human Reassortant DS-1-Like Rotavirus A Strains with G8P[8] Genotype in Human Patients in the Czech Republic.

Group A Rotaviruses (RVA) are the leading cause of acute gastroenteritis in children and a major cause of childhood mortality in low-income countries. RVAs are mostly host-specific, but interspecies transmission and reassortment between human and animal RVAs significantly contribute to their genetic diversity. We investigated the VP7 and VP4 genotypes of RVA isolated from 225 stool specimens collected from Czech patients with gastroenteritis during 2016-2019.

Multiple Virus Infections in Western Honeybee ( L.) Ejaculate Used for Instrumental Insemination.

Instrumental insemination of L. queens is a widely employed technique used in honeybee breeding that enables the effective control of mating. However, drone semen represents a potential source of honeybee viruses.

Human rotavirus A detection: Comparison of enzymatic immunoassay and rapid chromatographic test with two quantitative RT-PCR assays.

Objective: The aim of this study was to compare results of two commercially available kits used for routine detection of Rotavirus A in human stool samples with results of commercial quantitative reverse-transcription PCR (RT-qPCR) test and in-house RT-qPCR.

Material And Methods: In total, 749 stool samples were screen-ed with the use of four different methods. The samples were collected from four diagnostic laboratories from March 2016 to June 2017.

Congenital Microphthalmic Syndrome in a Swine.

A 17-week-old crossbred finishing pig was presented for lameness of approximately one week. Clinical evaluation, including ophthalmologic examination, revealed ataxia, partial flaccid paresis of the pelvic limbs, skin lesions at feet and claws, and severely reduced vision/blindness. Both eyes had multiple persistent pupillary membranes (iris-to-iris and iris-to-lens) and hypermature cataracts.

Monocyte derived macrophages as an appropriate model for porcine cytomegalovirus immunobiology studies.

Porcine cytomegalovirus (PCMV) causes lifelong latent infections in swine. The pathogen is occasionally associated with inclusion body rhinitis and pneumonia in piglets, reproductive disorders in pregnant sows and respiratory disease complex in older pigs. Immunosuppressive potential of PCMV infection is discussed.

Virucides in apiculture: persistence of surrogate enterovirus under simulated field conditions.

Background: Honeybee viruses have been recognized as being among the most important factors leading to colony losses worldwide. Colony food and faeces are regarded as possible sources of infectious viruses able to contaminate the environment and equipment of apiaries. Thus, methods for elimination of viruses are required.

Epidemiological survey of enteric viruses in wild boars in the Czech Republic: First evidence of close relationship between wild boar and human rotavirus A strains.

Population of wild boar is increasing in the whole Europe, the animals migrate close to human habitats which greatly increases the possibility of natural transmission between domestic animals or humans and wild boars. The aim of the study was to estimate in population of free-living wild boar in the Czech Republic the prevalence of enteric viral pathogens, namely rotavirus groups A and C (RVA and RVC), porcine reproductive and respiratory syndrome virus (PRRSV), and members of family Coronaviridae (transmissible gastroenteritis virus - TGEV, porcine epidemic diarrhea virus - PEDV, porcine respiratory coronavirus - PRCV, and porcine hemagglutination encephalomyelitis virus - PHEV) and Picornaviridae,(teschovirus A - PTV, sapelovirus A - PSV, and enterovirus G - EV-G). In our study, stool samples from 203 wild boars culled during hunting season 2014-2015 (from October to January) were examined by RT-PCR.

Detection of Diverse Novel Bat Astrovirus Sequences in the Czech Republic.

Astroviruses are a major cause of gastroenteritis in humans and animals. Recently, novel groups of astroviruses were identified in apparently healthy insectivorous bats. We report the detection of diverse novel astrovirus sequences in nine different European bat species: Eptesicus serotinus, Hypsugo savii, Myotis emarginatus, M.

[The possibilities of zoonotic transmission of rotaviruses].

Rotaviruses are significant enteric pathogens of humans and animals. Rotavirus-associated mortality is still high in children, especially in developing countries. Rotaviruses also account for important economic losses due to gastrointestinal disease of livestock animals, notably of young cattle and pigs.

Diversity of VP7, VP4, VP6, NSP2, NSP4, and NSP5 genes of porcine rotavirus C: phylogenetic analysis and description of potential new VP7, VP4, VP6, and NSP4 genotypes.

Rotavirus C (RVC) is a cause of gastroenteritis in swine and has a worldwide distribution. A total of 448 intestinal or faecal samples from pigs of all ages were tested for viruses causing gastroenteritis. RVC was detected in 118 samples (26.

Prevalence study and phylogenetic analysis of group C porcine rotavirus in the Czech Republic revealed a high level of VP6 gene heterogeneity within porcine cluster I1.

Group C rotavirus (RVC) has been described to be a causative agent of gastroenteritis in humans and animals. In the current study, the presence of porcine RVC was confirmed in 25.6 % of 293 porcine faecal samples collected from seven Czech farms.

Genetic diversity of porcine sapoviruses, kobuviruses, and astroviruses in asymptomatic pigs: an emerging new sapovirus GIII genotype.

Small, non-enveloped RNA viruses belonging to the genera Sapovirus, Kobuvirus, and Mamastrovirus are usually associated with gastroenteritis in humans and animals. These enteric pathogens are considered potential zoonotic agents. In this study, the prevalence and genetic diversity of sapoviruses (SaVs), kobuviruses (KoVs), and astroviruses (AstVs) in asymptomatic pigs were investigated using a PCR approach.