Viral Material Research Articles

Can Free Floating SARS-CoV-2 Viral Material Diminish the Amount of Epidermal Growth Factor and Promote Alzheimer Disease in Women with COVID-19 in Menopause Transition?

The question is raised if there are protein sequences of SARS-CoV-2 that stand-alone can cause neuro-gynecological damage. We found that free floating nucleocapsid can capture EGF and that likely SARS-CoV-2 spike can competitively inhibit TGFβ. Women in menopause transition are vulnerable to lack of EGF-to-EGFR. Therefore, in e.g. aftercare of COVID-19, it is wise to pay attention to cognitive functioning of those women.

Enhanced Detection of DNA Viruses in the Cerebrospinal Fluid of Encephalitis Patients Using Metagenomic Next-Generation Sequencing.

The long and expanding list of viral pathogens associated with causing encephalitis confounds current diagnostic procedures, and in up to 50% of cases, the etiology remains undetermined. Sequence-agnostic metagenomic next-generation sequencing (mNGS) obviates the need to specify targets in advance and thus has great potential in encephalitis diagnostics. However, the low relative abundance of viral nucleic acids in clinical specimens poses a significant challenge. Our protocol employs two novel techniques to selectively remove human material at two stages, significantly increasing the representation of viral material. Our bioinformatic workflow using open source protein- and nucleotide sequence-matching software balances sensitivity and specificity in diagnosing and characterizing any DNA viruses present. A panel of 12 cerebrospinal fluid (CSFs) from encephalitis cases was retrospectively interrogated by mNGS, with concordant results in seven of nine samples with a definitive DNA virus diagnosis, and a different herpesvirus was identified in the other two. In two samples with an inconclusive diagnosis, DNA viruses were detected and in a virus-negative sample, no viruses were detected. This assay has the potential to detect DNA virus infections in cases of encephalitis of unknown etiology and to improve the current screening tests by identifying new and emerging agents.

Virome assembly and annotation in brain tissue based on next-generation sequencing.

The glioblastoma multiforme (GBM) is one of the deadliest tumors. It has been speculated that virus plays a role in GBM but the evidences are controversy. Published researches are mainly limited to studies on the presence of human cytomegalovirus (HCMV) in GBM. No comprehensive assessment of the brain virome, the collection of viral material in the brain, based on recently sequenced data has been performed. Here, we characterized the virome from 111 GBM samples and 57 normal brain samples from eight projects in the SRA database by a tested and comprehensive assembly approach. The annotation of the assembled contigs showed that most viral sequences in the brain belong to the viral family Retroviridae. In some GBM samples, we also detected full genome sequence of a novel picornavirus recently discovered in invertebrates. Unlike previous reports, our study did not detect herpes virus such as HCMV in GBM from the data we used. However, some contigs that cannot be annotated with any known genes exhibited antibody epitopes in their sequences. These findings provide several avenues for potential cancer therapy: the newly discovered picornavirus could be a starting point to engineer novel oncolytic virus; and the exhibited antibody epitopes could be a source to explore potential drug targets for immune cancer therapy. By characterizing the virosphere in GBM and normal brain at a global level, the results from this study strengthen the link between GBM and viral infection which warrants the further investigation.

Proteotyping SARS-CoV-2 Virus from Nasopharyngeal Swabs: A Proof-of-Concept Focused on a 3 Min Mass Spectrometry Window.

Rapid but yet sensitive, specific, and high-throughput detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinical samples is key to diagnose infected people and to better control the spread of the virus. Alternative methodologies to PCR and immunodiagnostics that would not require specific reagents are worthy to investigate not only for fighting the COVID-19 pandemic but also to detect other emergent pathogenic threats. Here, we propose the use of tandem mass spectrometry to detect SARS-CoV-2 marker peptides in nasopharyngeal swabs. We documented that the signal from the microbiota present in such samples is low and can be overlooked when interpreting shotgun proteomic data acquired on a restricted window of the peptidome landscape. In this proof-of-concept study, simili nasopharyngeal swabs spiked with different quantities of purified SARS-CoV-2 viral material were used to develop a nanoLC–MS/MS acquisition method, which was then successfully applied on COVID-19 clinical samples. We argue that peptides ADETQALPQR and GFYAQGSR from the nucleocapsid protein are of utmost interest as their signal is intense and their elution can be obtained within a 3 min window in the tested conditions. These results pave the way for the development of time-efficient viral diagnostic tests based on mass spectrometry.

On the potential role of exosomes in the COVID-19 reinfection/reactivation opportunity

We propose here that one of the potential mechanisms for the relapse of the COVID-19 infection could be a cellular transport pathway associated with the release of the SARS-CoV-2-loaded exosomes and other extracellular vesicles. It is possible that this “Trojan horse” strategy represents possible explanation for the re-appearance of the viral RNA in the recovered COVID-19 patients 7–14 day post discharge, suggesting that viral material was hidden within such exosomes or extracellular vesicles during this “silence” time period and then started to re-spread again. Communicated by Ramaswamy H. Sarma

Survey of Serum Amyloid A and Bacterial and Viral Frequency Using qPCR Levels in Recently Captured Feral Donkeys from Death Valley National Park (California).

Simple SummaryThis study aimed to measure the inflammatory marker (Serum Amyloid A; SAA) derived from such pathogenic processes specifically bacterial and virus found in recently captured feral donkeys. Quantitative Real-Time PCR (qPCR) was performed to detect and quantify RNA and DNA viruses and bacterial DNA. Behavior, body condition score, nasal discharge, and coughing were found to be related in cases of Asinine Herpesvirus 2 (AHV-2) and Streptococcus equi subspecies zooepidemicus DNA. SAA concentrations descended with age, with foals presenting higher concentrations. Positive tests differed for AHV-2 and Streptococcus equi spp. zooepidemicus between sampling moments. In conclusion, donkeys caught in the wild may not be a source of disease for domestic horses. However, the transmission of some pathogens, such as Streptococcus equi subspecies zooepidemicus, and/or AHV-2, may occur.Feral donkey removal from state land has raised concerns in terms of disease transmission between equine species. Disease outbreaks may occur as a result of the relocation of animals to new environments. Virus and bacteria DNA load and serum amyloid A derived from the pathogenic processes that they involve were measured in recently captured donkeys. Blood and nasal swabs were collected from 85 donkeys (Death Valley National Park, Shoshone, California); 24 were retested after 30/60 days in the Scenic (Arizona) long-term holding facility co-mingled with feral donkeys from Arizona and Utah. Quantitative Real-Time PCR (qPCR) was performed to detect viral and bacterial genomic material (equine influenza A [EIV], equine rhinitis A and B viruses, AHV-2, AHV-3, AHV-5 and EHV-1, EHV-4, Streptococcus equi subspecies equi and zooepidemicus,). Significant relations between behavior, body condition score, nasal discharge, and coughing were found in donkeys for which AHV-2 and Streptococcus zooepidemicus DNA was detected. Higher SAA concentrations were found in foals. AHV-2 and Streptococcus zooepidemicus DNA concentrations significantly differed between sampling moments (p < 0.05). In conclusion, donkeys do not appear to be a substantial risk for disease transmission to horses but could be if they carried strangles or other processes in which AHV-2 and Streptococcus zooepidemicus were involved.

Recognition of Reovirus RNAs by the Innate Immune System.

Mammalian orthoreovirus (reovirus) is a dsRNA virus, which has long been used as a model system to study host–virus interactions. One of the earliest interactions during virus infection is the detection of the viral genomic material, and the consequent induction of an interferon (IFN) based antiviral response. Similar to the replication of related dsRNA viruses, the genomic material of reovirus is thought to remain protected by viral structural proteins throughout infection. Thus, how innate immune sensor proteins gain access to the viral genomic material, is incompletely understood. This review summarizes currently known information about the innate immune recognition of the reovirus genomic material. Using this information, we propose hypotheses about host detection of reovirus.

Virucidals Control the Presence of Covid in Mouth/Saliva

Summary: This pilot study evaluated the effects of some virucidals in vivo (RT-PCR swab test) to define the presence of COVID in the mouth saliva. With this model, if an asymptomatic subject is positive (in the mouth saliva, the first incubating medium), virucidals may be used and the positivity can re-evaluated to define their viral killing power. Results: A progressive decrease in positivity in the swab samples was observed. Virucidals’ produced disappearance of positivity in most subjects at 3 days. All virucidals used in this pilot registry resulted effective. The pharmaceutical form seems to be important to assure persisting traces of the virucidal in the mouth. Phyrorelief possibly produced the longest action (&gt;3 hours) due to its slower release. These observations indicate a significant effect of virucidals on the viral contamination of the mouth with a simple, cost-effective model. The lower presence of a virus charge may reduce contagiousness of most patients and possibly, the spread of viral material from the mouth. The effects on the evolution of COVID-19 on single patients is, unknown but virucidals may assume a significant community value in controlling spreading

Virucidals Control the Presence of Covid in Mouth/Saliva

Summary: This pilot study evaluated the effects of some virucidals in vivo (RT-PCR swab test) to define the presence of COVID in the mouth saliva. With this model, if an asymptomatic subject is positive (in the mouth saliva, the first incubating medium), virucidals may be used and the positivity can re-evaluated to define their viral killing power. Results: A progressive decrease in positivity in the swab samples was observed. Virucidals’ produced disappearance of positivity in most subjects at 3 days. All virucidals used in this pilot registry resulted effective. The pharmaceutical form seems to be important to assure persisting traces of the virucidal in the mouth. Phyrorelief possibly produced the longest action (&gt;3 hours) due to its slower release. These observations indicate a significant effect of virucidals on the viral contamination of the mouth with a simple, cost-effective model. The lower presence of a virus charge may reduce contagiousness of most patients and possibly, the spread of viral material from the mouth. The effects on the evolution of COVID-19 on single patients is, unknown but virucidals may assume a significant community value in controlling spreading.

Persistent SARS-CoV-2 infection and the risk for cancer

The current SARS-CoV-2 has put significant strain on healthcare services worldwide due to acute COVID-19. However, the potential long-term effects of this infection haven’t been extensively discussed.We hypothesize that SARS-CoV-2 may be able to cause persistent infection in some individuals, and should this be the case, that in a few years we may see a rise in cancer incidence due to carcinogenic effects of this coronavirus.Non-retroviral RNA viruses such as Coronaviridae have been shown to cause persistent infection in hosts. Empirical evidence of viral genomic material shedding weeks after apparent clinical and laboratorial resolution of COVID-19 may be an indirect proof for persistent viral infection. Furthermore, tropism towards certain immune-privileged territories may facilitate immune evasion by this virus.Structural homology with SARS-CoV-1 indicates that SARS-CoV-2 may be able to directly impair pRb and p53, which are key gatekeepers with tumor suppressor functions. Additionally, COVID-19 features preeminent inflammatory response with marked oxidative stress, which acts as both as initiator and promotor of carcinogenesis.Should there be a carcinogenic risk associated with SARS-CoV-2, the implications for public health are plenty, as infected patients should be closely watched during long periods of follow-up.Additional investigation to establish or exclude the possibility for persistent infection is paramount to identify and prevent possible complications in the future.

The effect of elicitors of bacterial origin on the functioning of the protective system of potato (&lt;i&gt;Solanum Tuberosum&lt;/i&gt; L.) seedlings infected with X-virus

The reactive oxygen species content, the activity of phenolic peroxidase, and the expression levels of genes encoding certain defense proteins were studied in potato seedlings grown on a substrate with the addition of a preparation based on B. subtilis and infected with potato virus Х. The accumulation of reactive oxygen species and the induction of the defense system components in potato leaves treated with this preparation and infected are shown. Less viral material was detected in experimental samples of potato seedlings compared with control untreated with B. subtilis.

Decrease in Covid-19 Contagiousness: Virucidals Control the Presence of Covid in Saliva and Salivary Glands

Summary: This pilot study evaluated the effects of some virucidals in vivo (using the RT-PCR swab test) to evaluate the presence of COVID in the mouth saliva. With this model, if an asymptomatic subject is positive (in the mouth saliva, the first incubating medium), virucidals can be used, i.e., for a week, and the positivity re-evaluated to define the direct killing power of the virucidal.Results: A progressive decrease in positivity in the swab samples was observed. Virucidals produced disappearance of positivity in most subjects at 3 and 7 days. All virucidals used in this pilot registry resulted effective. The pharmaceutical form seems to be important to assure persisting traces of the virucidal in the mouth. The gummy Phyrorelief CC possibly produced the longest action (&gt;3 hours) due to its slower release. These preliminary observations indicate a significant effect of virucidals on the viral contamination of the mouth (the first incubator) with a relatively simple, cost-effective model. The lower presence of a virus charge or its decrease may significantly reduce contagiousness of most of these patients and possibly, the spread of viral material. The effects on the evolution of COVID-19 on single patients is, unpredictable with this model but virucidals may assume a significant community value in preventing and controlling spreading.

Concentration of viruses and electron microscopy.

Nearly all lethal viral outbreaks in the past two decades were caused by newly emerging viruses. Viruses are often studied by electron microscopy (EM), which provides new high-resolution data on the structure of viral particles relevant to both fundamental virology and practical pharmaceutical nanobiotechnology. Electron microscopy is also applied to ecological studies to detect viruses in the environment, to analysis of technological processes in the production of vaccines and other biotechnological components, and to diagnostics. Despite the advances in more sensitive methods, electron microscopy is still in active use for diagnostics. The main advantage of EM is the lack of specificity to any group of viruses, which allows working with unknown materials. However, the main limitation of the method is the relatively high detection limit (107 particles/mL), requiring viral material to be concentrated. There is no most effective universal method to concentrate viruses. Various combinations of methods and approaches are used depending on the virus and the goal. A modern virus concentration protocol involves precipitation, centrifugation, filtration, and chromatography. Here we describe the main concentrating techniques exemplified for different viruses. Effective elution techniques are required to disrupt the bonds between filter media and viruses in order to increase recovery. The paper reviews studies on unique traps, magnetic beads, and composite polyaniline and carbon nanotubes, including those of changeable size to concentrate viral particles. It also describes centrifugal concentrators to concentrate viruses on a polyethersulfone membrane. Our review suggests that the method to concentrate viruses and other nanoparticles should be chosen with regard to objectives of the study and the equipment status of the laboratory.

Radiological findings for diagnosis of SARS-CoV-2 pneumonia (COVID-19)

On 31st December 2019, China reported that several cases of pneumonia of unknown origin had occurred in Wuhan (Hubei Province), the cause of which was identified on 7th January 2020: a new coronavirus initially named 2019 novel coronavirus (2019-nCoV). On 11th February, the World Health Organization (WHO) renamed the new virus SARS-CoV-2 due to the similarities between the cause of the severe acute respiratory syndrome that broke out in 2003 and COVID-19 (Coronavirus Infectious Disease 2019).1 On 30th January, WHO declared the outbreak a Public Health Emergency of International Interest, and a pandemic on 11th March. As of 21st March 2020, 311,314 cases have been reported in 188 affected countries, with 13,079 deaths as a result of the infection and 95,800 people recovered (https://www.worldometers.info/coronavirus/). The statistics probably reflect a bias toward the most serious cases, which have more contact with the health system. However, many cases may be undiagnosed, as they are asymptomatic patients who do not go to a health center or mild symptomatology cases that are not confirmed due to the limited availability of diagnostic tests in many countries, such as Spain. Therefore, these statistics are likely to underestimate mild and asymptomatic cases, with the pandemic having a higher prevalence.2 COVID-19 infection can develop as a mild, moderate, or severe illness, including severe pneumonia, acute respiratory distress syndrome (ARDS), sepsis, and septic shock. The incubation period ranges from about 5 days (interval: 4–7 days) to a maximum of 12–13 days. Mild cases may develop flu-like symptoms: high fever, myalgia, fatigue, and respiratory symptoms, especially dry cough, with possible progression to pneumonia. The onset is usually less abrupt than in the flu, and upper respiratory symptoms seem minor or absent.2, 3 The main source of infection is other patients already infected with SARS-CoV-2. This is transmitted through respiratory droplets (aerosols > 5 μm) over short distances (1.5–2 m) when patients cough, speak or sneeze, and through contaminated hands when in close contact with the mouth, nose, or bulbar conjunctiva. Prolonged contact represents the highest risk, with casual contacts being less likely to cause contagion. There can be infections from asymptomatic patients and even from people in the incubation period of the disease.2, 4 Transmission through infected surfaces is likely, with SARS-CoV-2 recently reported to remain on plastic and stainless steel up to 72 h.5 The diagnosis of COVID-19 disease is made through reverse transcription polymerase chain reaction [RT-PCR]) with the detection of nucleic acids of SARS-CoV-2 or by the virus's genetic sequencing. Pharyngeal or nasopharyngeal smear samples, sputum, stools, or blood may be used. The virus can also be isolated in airway epithelial cell cultures, but this is done exclusively in specialized laboratories.6 Therefore, RT-PCR screening is regarded as the gold standard laboratory test for the diagnosis of COVID-19. False negatives have been documented in some cases, likely due to inappropriate viral sample material or technical problems during nucleic acid extraction.7, 8, 9 The incidence of COVID-19 has been observed to be higher in men than in women, for which the influence of the X chromosome and sex hormones on innate and adaptive immunity has been suggested as a possible explanation.10, 11 The respiratory system is the first to be affected by COVID-19, so in suspicious cases it is common to request a chest X-ray (CXR) as the first imaging test. However, its diagnostic performance in the initial stages of the disease is limited, since it has been reported that pathological findings identifiable on chest computed tomography (CCT) may not be detected on X-rays.7, 12, 13 This fact, together with the initial circumstances of the epidemic, when the accumulation of suspected cases exceeded the availability of RT-PCR tests, led to certain working groups adopting CCT as a diagnostic test in the absence of RT-PCR, leading to an unprecedented number of CCT studies to try to characterize a novel infectious disease. The CCT obtained very good results in these studies, observing that the pathological findings of the CCT can occur even before the symptoms7, 12, 13 and be diagnostic in patients with initial RT-PCR false-negative results.7, 8, 14 Therefore, it was concluded that CCT is a very valuable tool to diagnose COVID-19 infection, both in the initial assessment of lung involvement and for its follow-up.7, 15, 16 This article aims to identify the characteristics of this rapidly progressive viral pneumonia on imaging tests, both on CXR and CCT. The characteristic imaging findings of the different stages of the disease, the evolution of the findings associated with the progression of the disease or with clinical improvement, and the variation in the prevalence of the different patterns according to the age of the patients are also explained.

Personal protective equipment during the coronavirus disease (COVID) 2019 pandemic - a narrative review.

Personal protective equipment has become an important and emotive subject during the current coronavirus disease 2019 epidemic. Coronavirus disease 2019 is predominantly caused by contact or droplet transmission attributed to relatively large respiratory particles which are subject to gravitational forces and travel only approximately 1 metre from the patient. Airborne transmission may occur if patient respiratory activity or medical procedures generate respiratory aerosols. These aerosols contain particles that may travel much longer distances and remain airborne longer, but their infective potential is uncertain. Contact, droplet and airborne transmission are each relevant during airway manoeuvres in infected patients, particularly during tracheal intubation. Personal protective equipment is an important component, but only one part, of a system protecting staff and other patients from coronavirus disease 2019 cross-infection. Appropriate use significantly reduces risk of viral transmission. Personal protective equipment should logically be matched to the potential mode of viral transmission occurring during patient care - contact, droplet or airborne. Recommendations from international organisations are broadly consistent, but equipment use is not. Only airborne precautions include a fitted high-filtration mask, and this should be reserved for aerosol generating procedures. Uncertainty remains around certain details of personal protective equipment including use of hoods, mask type and the potential for re-use of equipment.

Microbiological safety of marine products (seafood)

Recently more and more evidence appears, proving that seafood consumers should be referred to risk group in which outbreaks of viral food poisoning and foodborne infectious diseases occurs, transmitted by food route. There are several reasons to refer seafood to a category of epidemiologically non-safe products: high microbial pollution of adjacent seas with sewage waters; many non-fish hydrocoles are natural filter feeding animals, which are infected by viruses in the process of vital activity, passing through their organism water and food particles; sufficient viruses stability in external environment, enabling them to remain intact outside of host organism during of prolong time interval. Total rate of viral material detection in seafood samples may reach ~ 10 %. The authors by means of expertise determined virological effect of thermal seafood treatment used in housekeeping conditions and at public catering establishments for preparing mostly widespread dishes. In this paper a conclusion is made, that the use of seafood for preparing dishes, which technology does not consider sufficiently efficient in respect to viruses thermal treatment, shall include preliminary virologic survey of stuff for excluding viral pathogens and for provision safety of the corresponding food products.

Rapid immunochemical method for the detection of orthopoxviruses (Orthopoxvirus, Chordopoxvirinae, Poxviridae).

The abolition of smallpox vaccination has led to the disappearance of population immunity to pox viruses. However, the threat of infection by pathogenic orthopoxviruses persists and determines the need to develop sensitive and operational methods for indicating pathogens. Development of a sensitive, fast and easy-to-use immunochemical test for the detection of orthopoxviruses in the «point of care» format. We used preparations of cultural vaccinia virus (VV) with varying degrees of purification, polyclonal antibodies from hyperimmune rabbit serum, and equipment from a previously developed autonomous kit for dot-immunoassay on flat protein arrays. It has been established that rabbit polyclonal antibodies can be used in a single-stage dotanalysis, both as a capture agent immobilized on a substrate and as a detection reagent bound with colloidal gold particles. It is shown that the effectiveness of the detection of VV is inversely related to the degree of purification of viruses from sub-viral structures. The sensitivity of the rapid detection of viruses in a crude preparation was about 30 times higher than in pure viral material. The increase in sensitivity, presumably, occurs due to binding to the capture antibodies of subviral structures, which form large aggregates of sensitized gold particles. The test does not detect cross-reactions with heterogeneous viruses (measles, rubella and chickenpox) that cause exantematous diseases. The one-stage variant of the dot-immunoassay reduces the analysis time to 40 minutes and improves the detection sensitivity of orthopoxviruses in crude viral preparations to the range of 105-104 PFU / ml. Full makeup, ease of analysis and the ability to visually accounting for results allow the test to be used outside of laboratories.

Cell-to-Cell Spreading of HIV-1 in Myeloid Target Cells Escapes SAMHD1 Restriction.

Dendritic cells (DCs) and macrophages as well as osteoclasts (OCs) are emerging as target cells of HIV-1 involved in virus transmission, dissemination, and establishment of persistent tissue virus reservoirs. While these myeloid cells are poorly infected by cell-free viruses because of the high expression levels of cellular restriction factors such as SAMHD1, we show here that HIV-1 uses a specific and common cell-to-cell fusion mechanism for virus transfer and dissemination from infected T lymphocytes to the target cells of the myeloid lineage, including immature DCs (iDCs), OCs, and macrophages, but not monocytes and mature DCs. The establishment of contacts with infected T cells leads to heterotypic cell fusion for the fast and massive transfer of viral material into OC and iDC targets, which subsequently triggers homotypic fusion with noninfected neighboring OCs and iDCs for virus dissemination. These two cell-to-cell fusion processes are not restricted by SAMHD1 and allow very efficient spreading of virus in myeloid cells, resulting in the formation of highly virus-productive multinucleated giant cells. These results reveal the cellular mechanism for SAMHD1-independent cell-to-cell spreading of HIV-1 in myeloid cell targets through the formation of the infected multinucleated giant cells observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients.IMPORTANCE We demonstrate that HIV-1 uses a common two-step cell-to-cell fusion mechanism for massive virus transfer from infected T lymphocytes and dissemination to myeloid target cells, including dendritic cells and macrophages as well as osteoclasts. This cell-to-cell infection process bypasses the restriction imposed by the SAMHD1 host cell restriction factor for HIV-1 replication, leading to the formation of highly virus-productive multinucleated giant cells as observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients. Since myeloid cells are emerging as important target cells of HIV-1, these results contribute to a better understanding of the role of these myeloid cells in pathogenesis, including cell-associated virus sexual transmission, cell-to-cell virus spreading, and establishment of long-lived viral tissue reservoirs.

Influence of epizootic categories of birds on germ resistance

Non-plastic diseases are a problem both in medical and veterinary practice. The most common diseases in poultry caused by oncogenic viruses include lymphoid leukemia (LL) and Marek's disease (MD). A vaccine has been developed for HM. On breeds and lines of birds with high resistance to neoplasm, the vaccine is much better. It is possible to solve this problem by increasing the specific and overall resistance, by creating genetically disease-resistant lines and crosses of the bird. However, this requires some knowledge about the mechanism of disease resistance, the interaction of the pathogen with the body, ways to increase resistance, its correction, sensitivity of lines and hybrids to pathogens of the most common diseases. This requires criteria or markers that are indicators of the body's immunocompetence. The studies were performed on chickens of Leghorn D4 line and Poltava clay P37. The level of antibodies to leukemia-sarcoma complex (VLSC) viruses was determined in the neutralization reaction by a conventional method. As a viral material, a 30% suspension of tumors obtained from infected chickens with Raus sarcoma virus was used. The article presents data on the influence of epizootic categories of poultry on the resistance of embryos to oncornaviruses. For research, the bird by status with respect to antibodies to oncoviruses was divided into four categories: A+ the presence of antibodies; A- the absence of antibodies; B+ the presence of the virus; B- no virus. When selecting a resistant bird for neoplasm, only two categories A-B- and A+ B- are theoretically relevant. The possibility of obtaining offspring with or without antibodies, depending on the status of this phenomenon in his parents, was established. According to the data obtained in 60.0% of cases, the bird, free from neutralizing antibodies against HRV, can be obtained by mating cocks and chickens free of these antibodies. However, the absence of antibodies from parents cannot guarantee such in their offspring (approximately 40.0% were with antibodies). It may be that some of the offspring of the antibody-free bird do not have genetic resistance to infection and react with antibody production when in contact with the virus. If the chickens and roosters had antibodies, their offspring were only free from them in 31.3% of cases. These data, however, indicate that resistance to infection is inherited from offspring and from parents resistant to natural infection with oncoviruses, which makes it more likely to obtain resistant offspring (P &lt; 0.01). There is also a pattern of getting families free of counteracting factors: they are more likely to get from chickens and cocks that have no antibodies. However, not always the absence of antibodies in roosters and chickens guaranteed the absence of antibodies in their offspring.

Post-Epidemic Distribution of Schmallenberg Virus in Culicoides Arbovirus Vectors in Poland.

Pooled samples of female and male Culicoides midges (5146 and 332 pools, respectively) that corresponded to a total number of 124,957 specimens were collected between 2013–2017 in the vicinity of cattle barns that were distributed throughout Poland were analyzed for the presence of Schmallenberg virus (SBV) RNA. Sixty-six pools tested positive (1.2%) with mean Ct value of 34.95. The maximum likelihood estimated infection rate (MLE) was calculated at 0.53 per 1000 individuals; however, it peaked in 2016 with MLE of 3.7. Viral RNA was detected in C. obsoletus/scoticus complex, C. punctatus, and C. pulicaris pools. Moreover, viral material was present in nulliparous (virgin) Culicoides females (MLE 0.27) and for the first time reported in males (MLE 0.34), which suggests the possibility of transovarial route of SBV or virus RNA transmission, as both do not fed on host blood. The accuracy of targeted versus random SBV surveillance in Culicoides vectors was compared. The relationship between infection rate (expressed as minimum infection rate; MIR), in addition to MLE, was compared with the density of virus infected midges (DIM). In conclusion, the SBV infection rate in the vector was significantly higher in 2016 as compared to other surveillance years; this is consistent with the simultaneous increase in SBV seroprevalence (seroconversion) in ruminants during the same year.