Bovine Anti-leukemic Measures for Improving Live-Stock Farms in Belgorod and Kemerovo Regions of Russia

Bovine leukemia remains one of the most urgent viral diseases in veterinary medicine, and potentially dangerous for humans. The strategy of combating it is aimed at improving the existing measures and full recovery of agricultural enterprises. The quality of animal products is a priority in the field of food safety. The aim of the research was to develop effective antileukemic measures for the improvement of livestock farms in the Belgorod and Kemerovo regions. The proposed antileukemic measures are to increase the frequency of serological studies from 6-th months to the 2-3th months among animals in areas with poor leukemia in cattle, as well as to increase the sensitivity of immunodiffusion test (AGID) due to highly centrifigation of the tested samples and an increase in the temperature of incubation samples close to the physiological norm for animals. The improved technique of staging an immunodiffusion reaction (AGID) allows detecting an average of 12% more infected animals with BLV in comparison with the approved method of staging a serological reaction AGID. Intensive introduction of PCR diagnostics to identify the causative agent of bovine leukemia in young calves, after the neonatal age period, will allow detecting early infection of animals and adjusting the program of antileukemia measures in disadvantaged farms. The introduction of PCR diagnostics in calves in the postnatal period of development in permanently dysfunctional livestock farms will contribute to the recovery of young animals from cattle leukemia in dysfunctional farms. The proposed antileukemia measures for the improvement of livestock farms in the Belgorod and Kemerovo regions made it possible to develop effective preventive measures for disadvantaged farms, improving the epizootic situation in the regions. So, in 2021, it was possible to completely improve the permanently dysfunctional economy of the LLC « Pobeda» in the Belgorod region.

RESULTS OF THE QUESTIONNAIRE ON THE PRESENCE OF VIRAL INFECTION (COVID-19) OF A.N. SYZGANOV NSCSEMPLOYEES

По данным ВОЗ на 25 ноября 2020 г. официально зарегистрированных случаев COVID-19 60,3 миллиона человек в мире, 38,6 миллионов выздоровевших, летальный исход 1,42 миллиона. Казахстан также является одной из стран, серьезно пострадавших от COVID-19. В период с конца июня по июль 2020 г. в Казахстане произошел резкий рост заболеваемости, республика находилась в «красной» зоне из-за неутешительной эпидемиологической ситуации. Целью исследования явилась изучение эпидемиологической ситуации по COVID-19 среди сотрудников ННЦХ им. А.Н. Сызганова. Всего в исследование вошли 384 сотрудника в возрасте от 21 до 80 лет, составил 44,1 ± 0,3 года. Сотрудникам центра проводились исследования методом полимеразно - цепной реакции (ПЦР) диагностика, иммуноферментный анализ (ИФА) тестирование (на антитела к SARS-CoV-2), иммунохемилюминесцентный анализ (ИХЛА) (для выявления общих антител к SARS-CoV-2) и компьютерная томография (КТ) грудной клетки. В результате исследования всего анкетировано - 384 сотрудников, из них по анкете заболевших вирусной инфекцией - 174 человека (45,7 %). Был сделан вывод, что 76,6% персонала переболели в легкой степени Ковид - 1 COVID-199, и доказана была благополучная эпидемиологическая ситуация с выскочим сформированным коллективным иммунитетам. Рекомендуем по полученным результатам исследования, что нецелесообразно определять антитела к COVID - 19 в течения месяца, лучше определять с помощью метода ИХЛА через три месяца. According to the WHO, there are 60.3 million officially registered COVID-19 casesin the world, 38.6 million recovered, and a death rate of 1.42 millionby November 25, 2020. Kazakhstan is also one of the countries severely affected by COVID-19. In the period from the end of June to July 2020, there was a sharp increase in the incidence in Kazakhstan, moreover, Kazakhstan was in the "red" zone due to the disappointing epidemiological situation. A study of the viral infection (COVID-19) epidemiological situationamong employees of the A.N. Syzganov NSCS. The centerstaff were studied by the method of polymerase chain reaction (PCR) diagnostics, enzyme-linked immunosorbent assay (ELISA) testing (for antibodies to SARS-CoV-2), сhemiluminescent immunoassay (CLIA) (to identify common antibodies to SARS-CoV-2) and computer tomography (CT) of the chest. In total, the study included 384 employees of the NSCS aged from 21 to 80 years, average age was 44.1 ± 0.3. 81 men and 303 women were examined: 54 of them were doctors, 188 nurses, 90 junior medical staff, and the other 52 employees. In total, 384 employees were interviewed (questioned), 174 (45.7%) were infected with a viral infection according to the questionnaire. In accordance with studyresults, it can be concluded that 76.6% of NSCS employees have had a viral infection (COVID - 19) and a sufficient immune layer has formed in the team to maintain a favorable epidemiological situation in the next six months. Based on the studyresults, we recommend, that it is inappropriate to determine antibodies to COVID-19 within a month, it is better to determine using the CLIA method after three months

Establishment of a specimen panel for the decentralised technical evaluation of the sensitivity of 31 rapid diagnostic tests for SARS-CoV-2 antigen, Germany, September 2020 to April 2021

Introduction The detection of SARS-CoV-2 with rapid diagnostic tests (RDT) has become an important tool to identify infected people and break infection chains. These RDT are usually based on antigen detection in a lateral flow approach. Aim We aimed to establish a comprehensive specimen panel for the decentralised technical evaluation of SARS-CoV-2 antigen rapid diagnostic tests. Methods While for PCR diagnostics the validation of a PCR assay is well established, there is no common validation strategy for antigen tests, including RDT. In this proof-of-principle study we present the establishment of a panel of 50 pooled clinical specimens that cover a SARS-CoV-2 concentration range from 1.1 × 109 to 420 genome copies per mL of specimen. The panel was used to evaluate 31 RDT in up to six laboratories. Results Our results show that there is considerable variation in the detection limits and the clinical sensitivity of different RDT. We show that the best RDT can be applied to reliably identify infectious individuals who present with SARS-CoV-2 loads down to 106 genome copies per mL of specimen. For the identification of infected individuals with SARS-CoV-2 loads corresponding to less than 106 genome copies per mL, only three RDT showed a clinical sensitivity of more than 60%. Conclusions Sensitive RDT can be applied to identify infectious individuals with high viral loads but not to identify all infected individuals.

Extrachromosomal viral DNA produced by transcriptionally active endogenous viral elements in non-infected banana hybrids impedes quantitative PCR diagnostics of banana streak virus infections in banana hybrids

The main edible and cultivated banana varieties are intra- and interspecific hybrids of the two main Musa species, Musa acuminata and Musa balbisiana, having diploid genomes denoted A and B, respectively. The B genome naturally hosts sequences of banana streak virus (BSV) named endogenous BSV (eBSV). Upon stress, eBSVs are identified as the origin of BSV infection for at least three BSV species, causing banana streak disease. For each of the three species, BSV and eBSV share >99.9 % sequence identity, complicating PCR-based diagnosis of viral infection in the B genome-containing bananas. Here, we designed a quantitative PCR-based method to only quantify episomal BSV particles produced, overcoming the limitation of eBSV also being detected by qPCR by using it as a ‘calibrator’. However, our results revealed unexpected variation of eBSV amplification in calibrator plants composed of a clonal population of 53 replicating virus-free banana hybrids with the same AAB genotype. Our in-depth molecular analyses suggest that this calibrator variation is due to the variable abundance of non-encapsidated extrachromosomal viral DNA, likely produced via the transcription of eBSVs, followed by occasional reverse transcription. We also present evidence that accumulation of viral transcripts in AAB plants is downregulated both at post-transcriptional and transcriptional levels by an RNA interference mechanism that keeps the plants free of virus infection. Finally, we recommend that such eBSV amplification variation be taken into account to establish a quantitative viral diagnostic for banana plants with the B genome.

The Current State of the Protected Apis mellifera mellifera Population in Russia: Hybridization and Nosematosis

The Southern Urals of Russia are the habitat of one of the surviving populations of the dark forest bee—the Burzyan population of Apis mellifera mellifera. In this study, we present the results of the subspecies identification of bee colonies in the Altyn-Solok Nature Reserve in the Southern Ural Mountains using the intergenic mtDNA COI-COII locus and the assessment of the prevalence of nosematosis. Analysis of the mtDNA COI-COII intergenic locus in the studied sample showed that 30.4% of the colonies belong to the lineage C. The PCR diagnostics of nosematosis in 92 colonies selected from different sectors of the Altyn-Solok Nature Reserve showed that about half of the analyzed colonies were infected with Nosema apis. Nosema ceranae was found in eight colonies. Both of these factors can lead to the extinction of this population of the dark forest bee.

Molecular genetic methods in biomedical research. Part III: human gene diagnostics in clinical practice

Application of molecular genetic methods in the diagnosis and treatment of human diseases is extremely wide due to a huge amount of hereditary information contained in the human genome. Gene diagnostics allows establishing predisposition to diseases, identification of genetic abnormalities and prediction of pathological outcomes. In addition, gene diagnostics also enables prediction of the individual response to treatment in order to achieve the maximum therapeutic effect. Among all molecular genetic methods, polymerase chain reaction (PCR) diagnostics is a leading approach. Technical simplicity, low cost, high sensitivity and reliability of the method have made PCR diagnostics a routine modality for the risk assessment, diagnostics, and monitoring of the treatment efficiency. Here, we consider the application of PCR diagnostics for the abovementioned tasks and talk about the real-life examples of detecting mutations and chromosomal aberrations which may cause a disease. Further, we discuss the prospects of using a semi-quantitative PCR in medical practice and focus on pharmacogenetics as a key component of a personalised therapy. The lecture is aimed primarily at biomedical students and physicians and represents a continuation of the previous lectures published in Fundamental and Clinical Medicin.

Tips for a reduction of false positives in manual RT-PCR diagnostics of SARS-CoV-2

RT-PCR is the standard gold technique for testing the presence of RNA of the coronavirus causing Severe Acute Respiratory Syndrome (SARS-CoV-2) due to its high specificity and sensitivity. Despite its general use and reliability, no lab in the world is immune to the generation of false positives. These errors cause a loss of confidence in the technique's power and damage the image of laboratories. More importantly, they can take a toll on tested individuals and have economic, psychological, and health-associated effects. Most false positives are caused during a manual operation inside the laboratory. However, not much has been published about the errors associated with particular laboratory techniques used to detect the virus since the beginning of the actual pandemic. This work precisely reflects on events that occur during manual RT-PCR diagnostics in a COVID-19 laboratory, providing tips for reducing false-positive results.

Rapid screening for variants of concern in routine SARS-CoV-2 PCR diagnostics

The emerging spread of variants of concern (VOC) of SARS-CoV-2 has been noted in several countries worldwide during last months. VOCs associated with increased transmissibility and morality. Sequencing is the gold standard for investigation of variants, however it is expensive and time-consuming. S-dropout routine monitoring in combination with VOC screening by RT-PCR is a useful tool for VOC surveillance.