The factors influencing hepatitis E virus (HEV) circulation remain largely unexplored. We investi... more The factors influencing hepatitis E virus (HEV) circulation remain largely unexplored. We investigated HEV seroprevalence in humans and the prevalence of infection in farm pigs and rabbits in different regions of the Russian Federation, as well as the genetic diversity and population dynamics of the HEV. The anti-HEV IgG antibody detection rates in the general population increase significantly with age, from 1.5% in children and adolescents under 20 years old to 4.8% in adults aged between 20 and 59 years old to 16.7% in people aged 60 years and older. HEV seroprevalence varies between regions, with the highest rate observed in Belgorod Region (16.4% compared with the national average of 4.6%), which also has the country’s highest pig population. When compared with the archival data, both increases and declines in HEV seroprevalence have been observed within the last 10 years, depending on the study region. Virus shedding has been detected in 19 out of the 21 pig farms surveyed. On ...
A total of 104 sera sampled from vaccinated (“Sputnik V”, Russia) volunteers were tested in paral... more A total of 104 sera sampled from vaccinated (“Sputnik V”, Russia) volunteers were tested in parallel to determine different markers of humoral immunity against SARS-CoV-2. Testing was conducted using the neutralizing antibodies titer (NtAb) in the virus neutralization assay (VNA), the IgG to RBD in the quantitative ELISA (BAU/ml), the avidity index (AI) of the IgG to RBD (also in ELISA), and the titers of “neutralizing antibodies” which can block an interaction between human ACE2 and the viral RBD proteins in a competitive ELISA surrogate virus neutralization test (sVNT). The correlation coefficients between the quantitative results in the tried ELISA assays and the “true” NtAb titers in the VNA were high, with the following values: r=0.86 for BAU/ml (95% confidence interval, CI: 0.80-0.91, p<0.0001); 0.54 for the AI (95% CI: 0,38-0,67, p<0.0001); and 0.84 for the sVNT titer (95% CI:0.79-0.90). Additionally, it was found that the multiplicative index of BAU/ml × AI (which corresponds to the concentration of the high-affinity fraction of the total IgG to the RBD) gives a maximum correlation to the NtAb titers (r=0.89, 95% CI: 0.84-0.92, p<0.0001). The sensitivity and specificity, respectively, of the tested ELISA assays in recognizing the supposedly protective NtAb titer of ≥1:160 were the following: for the BAU/ml – 87.7±8% and 97.4±5%; for the (BAU/ml × AI) index – 92.3±6.5% and 97.4±5%; for the sVNT—95.4±5.1% and 89.7±9.5%. This confirms that the tested ELISA technologies have potential as a safe and cheap alternative to the classical VNA for assessing the protective force of patient immunity against SARSCoV- 2 infection in routine clinical practice.
Bulletin of Russian State Medical University, 2018
Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring ... more Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring its safety for the population. It is often necessary to collect aerosol samples from large areas in short time, which demands excellent particle collection efficiency, a sufficient incoming air flow rate and a capacity to maintain the viability of the collected samples. Below we present the aerosol sampler with a high volumetric flow rate based on a two-stage particle concentration algorithm and consisting of a virtual impactor and a cyclone concentrator with a recirculating liquid phase. We provide all necessary calculations and an algorithm for modeling impactor parameters. The sampler was tested using dry and liquid formulations dispersed into the particles of 0.5 to 5 μm in diameter. We demonstrate that at volumetric flow rates over 4,000 l/min efficiency of particle collection into the liquid phase at a volume of 10 ml makes over 20% of the total aerosol mass and at volumetric flow ...
Bulletin of Russian State Medical University, 2018
Air quality monitoring is essential when it comes to protecting the urban population, especially ... more Air quality monitoring is essential when it comes to protecting the urban population, especially that of big metropolises, from biohazards including biopathogens (BPs). This process is aided by different samplers and analyzers of aerosol pollutants, filters and disinfection systems. Their performance is tested using experimental aerosol formulations with a predetermined composition. Unfortunately, the majority of such systems available in Russia are only able to process a few hundred liters of air per time unit, which is too little. Big aerosol chambers (10 to 20 m3) are very expensive and may not fit into a lab, necessitating an extensive overhaul. In this work we present a workstation for the detection of BP markers under controlled conditions based on the microbiological safety box MSB-III-Laminar-C-1.5 (380.150.01) that was originally designed to test the performance of samplers and analyzers of experimental aerosol formulations. Our workstation can handle the majority of BSL-1-...
A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 y... more A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018–2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republi...
A total of 381 hepatitis B virus (HBV) DNA sequences collected from 9 groups of Siberian native p... more A total of 381 hepatitis B virus (HBV) DNA sequences collected from 9 groups of Siberian native populations were phylogenetically analyzed along with 179 HBV strains sampled in different urban populations of former western USSR republics and 50 strain from Central Asian republics and Mongolia. Different HBV subgenotypes predominated in various native Siberian populations. Subgenotype D1 was dominant in Altaian Kazakhs (100%), Tuvans (100%), and Teleuts (100%) of southern Siberia as well as in Dolgans and Nganasans (69%), who inhabit the polar Taimyr Peninsula. D2 was the most prevalent subgenotype in the combined group of Nenets, Komi, and Khants of the northern Yamalo-Nenets Autonomous Region (71%), and in Yakuts (36%) from northeastern Siberia. D3 was the main subgenotype in South Altaians (76%) and Buryats (40%) of southeastern Siberia, and in Chukchi (51%) of the Russian Far East. Subgenotype C2 was found in Taimyr (19%) and Chukchi (27%), while subgenotype A2 was common in Yaku...
Surface-enhanced Raman scattering (SERS) spectroscopy is a surface- or cavity-enhanced variant of... more Surface-enhanced Raman scattering (SERS) spectroscopy is a surface- or cavity-enhanced variant of Raman scattering spectroscopy that allows the detection of analytes with a sensitivity down to single molecules. This method involves the use of SERS-active surfaces or cavities capable of concentrating incident radiation into small mode volumes containing the analyte. Here, we have engineered an ultranarrow metal–dielectric nano-cavity out of a film of the receptor-binding domain (RBD) of SARS-CoV-2 spike (S) glycoprotein and a silver surface, held together by interaction between reduced protein sulfhydryl groups and silver. The concentration of light in this nano-cavity allows the label-free recording of the characteristic Raman spectra of protein samples smaller than 1 pg. This is sufficient for the ultrasensitive detection of viral protein antigens at physiologically relevant levels. Moreover, the protein SERS signal can be increased by several orders of magnitude by coating the RBD...
Mass vaccination campaigns against COVID-19 affected more than 90% of the population in most deve... more Mass vaccination campaigns against COVID-19 affected more than 90% of the population in most developed countries. The new epidemiologic wave of COVID-19 has been ongoing since the end of 2021. It is caused by a virus variant B.1.1.529, also known as “Omicron” and its descendants. The effectiveness of major vaccines against Omicron is not known. The purpose of this study is to evaluate the efficacy of the Sputnik V vaccine. The main goal is to assess its protection against hospitalization in the period of Omicron dominance. We conducted our study based on a large clinical center in Moscow (Russia) where 1112 patients were included. We used the case-population method to perform the calculations. The data we obtained indicate that the Omicron variant causes at least 90% of infections in the studied cohort. The effectiveness of protection against hospitalization with COVID-19 in our study was 85.9% (95% CI 83.0–88.0%) for those who received more than one dose. It was 87.6% (95% CI 85.4–...
The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild... more The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild (outpatient) course of COVID-19, including 39 primarily and 36 secondarily reinfected, and 92 patients with a severe (hospital) course of COVID-19, including 82 primarily and 10 secondarily infected. The AI was shown to correlate with the severity of repeated disease. In the group of outpatients with a mild course, the reinfected patients had significantly higher median AIs than those with primary infections (82.3% vs. 37.1%, p < 0.0001). At the same time, in patients with a severe course of COVID-19, reinfected patients still had low-avidity antibodies (median AI of 28.4% vs. 25% in the primarily infected, difference not significant, p > 0.05). This suggests that the presence of low-avidity IgG to RBD during reinfection is a negative prognostic factor, in which a patient’s risk of developing COVID-19 in a severe form is significantly increased. Thus, patients with IgG of low avid...
With the ELISA and Western blot (WB) data and Table S2. with the clinical symptoms in mice, immun... more With the ELISA and Western blot (WB) data and Table S2. with the clinical symptoms in mice, immunized by different schemes. (PDF 158Â kb)
Gushchin VA1,2 , Manuilov VA1,3, Mazunina EP1, Kleymenov DA1, Semenenko TA4, Gintsburg AL5, Tkach... more Gushchin VA1,2 , Manuilov VA1,3, Mazunina EP1, Kleymenov DA1, Semenenko TA4, Gintsburg AL5, Tkachuk AP1 IMMUNOLOGICAL MEMORY AS A BASIS FOR A WISE VACCINATION STRATEGY. A RATIONALE FOR INTRODUCING A COMPREHENSIVE SEROEPIDEMIOLOGICAL SURVEILLANCE SYSTEM IN RUSSIA ИММУНОЛОГИЧЕСКАЯ ПАМЯТЬ КАК ОСНОВА РАЦИОНАЛЬНОЙ ВАКЦИНОПРОФИЛАКТИКИ НАСЕЛЕНИЯ. ОБОСНОВАНИЕ СОЗДАНИЯ СИСТЕМЫ СЕРОЭПИДЕМИОЛОГИЧЕСКОГО МОНИТОРИНГА В РОССИИ
Mycobacterium tuberculosis Beijing genotype associated with drug resistance is a growing public h... more Mycobacterium tuberculosis Beijing genotype associated with drug resistance is a growing public health problem worldwide. The aim of this study was the assessment of virulence for C57BL/6 mice after infection by clinical M. tuberculosis strains 267/47 and 120/26, which belong to the modern sublineages B0/W148 and Central Asia outbreak of the Beijing genotype, respectively. The sublineages were identified by the analysis of the strains’ whole-genomes. The strains 267/47 and 120/26 were characterized as agents of pre-extensively drug-resistant (pre-XDR) and multidrug-resistant (MDR) tuberculosis, respectively. Both clinical strains were slow-growing in 7H9 broth compared to the M. tuberculosis H37Rv strain. The survival rates of C57BL/6 mice infected by 267/47, 120/26, and H37Rv on the 150th day postinfection were 10%, 40%, and 70%, respectively. Mycobacterial load in the lungs, spleen, and liver was higher and histopathological changes were more expressed for mice infected by the 267...
The factors influencing hepatitis E virus (HEV) circulation remain largely unexplored. We investi... more The factors influencing hepatitis E virus (HEV) circulation remain largely unexplored. We investigated HEV seroprevalence in humans and the prevalence of infection in farm pigs and rabbits in different regions of the Russian Federation, as well as the genetic diversity and population dynamics of the HEV. The anti-HEV IgG antibody detection rates in the general population increase significantly with age, from 1.5% in children and adolescents under 20 years old to 4.8% in adults aged between 20 and 59 years old to 16.7% in people aged 60 years and older. HEV seroprevalence varies between regions, with the highest rate observed in Belgorod Region (16.4% compared with the national average of 4.6%), which also has the country’s highest pig population. When compared with the archival data, both increases and declines in HEV seroprevalence have been observed within the last 10 years, depending on the study region. Virus shedding has been detected in 19 out of the 21 pig farms surveyed. On ...
A total of 104 sera sampled from vaccinated (“Sputnik V”, Russia) volunteers were tested in paral... more A total of 104 sera sampled from vaccinated (“Sputnik V”, Russia) volunteers were tested in parallel to determine different markers of humoral immunity against SARS-CoV-2. Testing was conducted using the neutralizing antibodies titer (NtAb) in the virus neutralization assay (VNA), the IgG to RBD in the quantitative ELISA (BAU/ml), the avidity index (AI) of the IgG to RBD (also in ELISA), and the titers of “neutralizing antibodies” which can block an interaction between human ACE2 and the viral RBD proteins in a competitive ELISA surrogate virus neutralization test (sVNT). The correlation coefficients between the quantitative results in the tried ELISA assays and the “true” NtAb titers in the VNA were high, with the following values: r=0.86 for BAU/ml (95% confidence interval, CI: 0.80-0.91, p&lt;0.0001); 0.54 for the AI (95% CI: 0,38-0,67, p&lt;0.0001); and 0.84 for the sVNT titer (95% CI:0.79-0.90). Additionally, it was found that the multiplicative index of BAU/ml × AI (which corresponds to the concentration of the high-affinity fraction of the total IgG to the RBD) gives a maximum correlation to the NtAb titers (r=0.89, 95% CI: 0.84-0.92, p&lt;0.0001). The sensitivity and specificity, respectively, of the tested ELISA assays in recognizing the supposedly protective NtAb titer of ≥1:160 were the following: for the BAU/ml – 87.7±8% and 97.4±5%; for the (BAU/ml × AI) index – 92.3±6.5% and 97.4±5%; for the sVNT—95.4±5.1% and 89.7±9.5%. This confirms that the tested ELISA technologies have potential as a safe and cheap alternative to the classical VNA for assessing the protective force of patient immunity against SARSCoV- 2 infection in routine clinical practice.
Bulletin of Russian State Medical University, 2018
Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring ... more Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring its safety for the population. It is often necessary to collect aerosol samples from large areas in short time, which demands excellent particle collection efficiency, a sufficient incoming air flow rate and a capacity to maintain the viability of the collected samples. Below we present the aerosol sampler with a high volumetric flow rate based on a two-stage particle concentration algorithm and consisting of a virtual impactor and a cyclone concentrator with a recirculating liquid phase. We provide all necessary calculations and an algorithm for modeling impactor parameters. The sampler was tested using dry and liquid formulations dispersed into the particles of 0.5 to 5 μm in diameter. We demonstrate that at volumetric flow rates over 4,000 l/min efficiency of particle collection into the liquid phase at a volume of 10 ml makes over 20% of the total aerosol mass and at volumetric flow ...
Bulletin of Russian State Medical University, 2018
Air quality monitoring is essential when it comes to protecting the urban population, especially ... more Air quality monitoring is essential when it comes to protecting the urban population, especially that of big metropolises, from biohazards including biopathogens (BPs). This process is aided by different samplers and analyzers of aerosol pollutants, filters and disinfection systems. Their performance is tested using experimental aerosol formulations with a predetermined composition. Unfortunately, the majority of such systems available in Russia are only able to process a few hundred liters of air per time unit, which is too little. Big aerosol chambers (10 to 20 m3) are very expensive and may not fit into a lab, necessitating an extensive overhaul. In this work we present a workstation for the detection of BP markers under controlled conditions based on the microbiological safety box MSB-III-Laminar-C-1.5 (380.150.01) that was originally designed to test the performance of samplers and analyzers of experimental aerosol formulations. Our workstation can handle the majority of BSL-1-...
A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 y... more A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018–2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republi...
A total of 381 hepatitis B virus (HBV) DNA sequences collected from 9 groups of Siberian native p... more A total of 381 hepatitis B virus (HBV) DNA sequences collected from 9 groups of Siberian native populations were phylogenetically analyzed along with 179 HBV strains sampled in different urban populations of former western USSR republics and 50 strain from Central Asian republics and Mongolia. Different HBV subgenotypes predominated in various native Siberian populations. Subgenotype D1 was dominant in Altaian Kazakhs (100%), Tuvans (100%), and Teleuts (100%) of southern Siberia as well as in Dolgans and Nganasans (69%), who inhabit the polar Taimyr Peninsula. D2 was the most prevalent subgenotype in the combined group of Nenets, Komi, and Khants of the northern Yamalo-Nenets Autonomous Region (71%), and in Yakuts (36%) from northeastern Siberia. D3 was the main subgenotype in South Altaians (76%) and Buryats (40%) of southeastern Siberia, and in Chukchi (51%) of the Russian Far East. Subgenotype C2 was found in Taimyr (19%) and Chukchi (27%), while subgenotype A2 was common in Yaku...
Surface-enhanced Raman scattering (SERS) spectroscopy is a surface- or cavity-enhanced variant of... more Surface-enhanced Raman scattering (SERS) spectroscopy is a surface- or cavity-enhanced variant of Raman scattering spectroscopy that allows the detection of analytes with a sensitivity down to single molecules. This method involves the use of SERS-active surfaces or cavities capable of concentrating incident radiation into small mode volumes containing the analyte. Here, we have engineered an ultranarrow metal–dielectric nano-cavity out of a film of the receptor-binding domain (RBD) of SARS-CoV-2 spike (S) glycoprotein and a silver surface, held together by interaction between reduced protein sulfhydryl groups and silver. The concentration of light in this nano-cavity allows the label-free recording of the characteristic Raman spectra of protein samples smaller than 1 pg. This is sufficient for the ultrasensitive detection of viral protein antigens at physiologically relevant levels. Moreover, the protein SERS signal can be increased by several orders of magnitude by coating the RBD...
Mass vaccination campaigns against COVID-19 affected more than 90% of the population in most deve... more Mass vaccination campaigns against COVID-19 affected more than 90% of the population in most developed countries. The new epidemiologic wave of COVID-19 has been ongoing since the end of 2021. It is caused by a virus variant B.1.1.529, also known as “Omicron” and its descendants. The effectiveness of major vaccines against Omicron is not known. The purpose of this study is to evaluate the efficacy of the Sputnik V vaccine. The main goal is to assess its protection against hospitalization in the period of Omicron dominance. We conducted our study based on a large clinical center in Moscow (Russia) where 1112 patients were included. We used the case-population method to perform the calculations. The data we obtained indicate that the Omicron variant causes at least 90% of infections in the studied cohort. The effectiveness of protection against hospitalization with COVID-19 in our study was 85.9% (95% CI 83.0–88.0%) for those who received more than one dose. It was 87.6% (95% CI 85.4–...
The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild... more The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild (outpatient) course of COVID-19, including 39 primarily and 36 secondarily reinfected, and 92 patients with a severe (hospital) course of COVID-19, including 82 primarily and 10 secondarily infected. The AI was shown to correlate with the severity of repeated disease. In the group of outpatients with a mild course, the reinfected patients had significantly higher median AIs than those with primary infections (82.3% vs. 37.1%, p < 0.0001). At the same time, in patients with a severe course of COVID-19, reinfected patients still had low-avidity antibodies (median AI of 28.4% vs. 25% in the primarily infected, difference not significant, p > 0.05). This suggests that the presence of low-avidity IgG to RBD during reinfection is a negative prognostic factor, in which a patient’s risk of developing COVID-19 in a severe form is significantly increased. Thus, patients with IgG of low avid...
With the ELISA and Western blot (WB) data and Table S2. with the clinical symptoms in mice, immun... more With the ELISA and Western blot (WB) data and Table S2. with the clinical symptoms in mice, immunized by different schemes. (PDF 158Â kb)
Gushchin VA1,2 , Manuilov VA1,3, Mazunina EP1, Kleymenov DA1, Semenenko TA4, Gintsburg AL5, Tkach... more Gushchin VA1,2 , Manuilov VA1,3, Mazunina EP1, Kleymenov DA1, Semenenko TA4, Gintsburg AL5, Tkachuk AP1 IMMUNOLOGICAL MEMORY AS A BASIS FOR A WISE VACCINATION STRATEGY. A RATIONALE FOR INTRODUCING A COMPREHENSIVE SEROEPIDEMIOLOGICAL SURVEILLANCE SYSTEM IN RUSSIA ИММУНОЛОГИЧЕСКАЯ ПАМЯТЬ КАК ОСНОВА РАЦИОНАЛЬНОЙ ВАКЦИНОПРОФИЛАКТИКИ НАСЕЛЕНИЯ. ОБОСНОВАНИЕ СОЗДАНИЯ СИСТЕМЫ СЕРОЭПИДЕМИОЛОГИЧЕСКОГО МОНИТОРИНГА В РОССИИ
Mycobacterium tuberculosis Beijing genotype associated with drug resistance is a growing public h... more Mycobacterium tuberculosis Beijing genotype associated with drug resistance is a growing public health problem worldwide. The aim of this study was the assessment of virulence for C57BL/6 mice after infection by clinical M. tuberculosis strains 267/47 and 120/26, which belong to the modern sublineages B0/W148 and Central Asia outbreak of the Beijing genotype, respectively. The sublineages were identified by the analysis of the strains’ whole-genomes. The strains 267/47 and 120/26 were characterized as agents of pre-extensively drug-resistant (pre-XDR) and multidrug-resistant (MDR) tuberculosis, respectively. Both clinical strains were slow-growing in 7H9 broth compared to the M. tuberculosis H37Rv strain. The survival rates of C57BL/6 mice infected by 267/47, 120/26, and H37Rv on the 150th day postinfection were 10%, 40%, and 70%, respectively. Mycobacterial load in the lungs, spleen, and liver was higher and histopathological changes were more expressed for mice infected by the 267...
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Papers by Artem Tkachuk