Microbiology Independent Research Journal (MIR Journal)
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A broad-range PCR technique for the diagnosis of culture-negative osteomyelitis
Get PDFOsteomyelitis is a rare disease that is often caused by an infection. In case of microbiology analyses failure, molecular assay seems appropriate for the identification of the pathogen. Broad-range PCR is a popular tool to amplify the gene of 16S ribosomal RNA – the component of the 30S subunit of the bacterial ribosome present in various species. The subsequent sequencing of the amplified gene enables scientists to determine the bacteria species. In this review, we discuss studies and case reports where the osteomyelitis causative agent was revealed by means of broad-range PCR. The purpose of the analysis is to assess the relevance and significance of this method for the diagnosis of osteomyelitis in patients. Numerous successful applications of wide-range PCR followed by sequencing in order to identify the causative agent of osteomyelitis have proven that this method is a useful tool in cases where the culture analysеs showed negative results
Evidence for the extracellular delivery of influenza NS1 protein
Get PDFWe constructed a reporter influenza A/Puerto Rico/8/1934 virus expressing truncated 124aa N-terminal NS1 protein fused to a luciferase reporter sequence (NanoLuc) without signal peptide. The reproduction activity of the vector correlated well with the luminescent activity in the lysates of infected cell cultures or mouse respiratory organ suspensions. Surprisingly, we found that luciferase enzymatic activity was present not only in the intracellular compartments but also in cell culture supernatants as well as in the sera or bronchiolar lavages of infected mice. This fact allowed us to formulate a working hypothesis about the extracellular delivery mechanism of the NS1 protein. To test this idea, we conducted co-transfection experiments in Vero cells with different combinations of plasmids encoding influenza genomic segments and chimeric NS1-NanoLuc encoding plasmid. We found that the emergence of the luciferase reporter in the extracellular compartment was promoted by the formation of the ribonucleoprotein complex (RNP) from the co-transfection of plasmids expressing PB1, PB2, PA, and NP proteins. Therefore, influenza NS1 protein may be delivered to the extracellular compartment together with the nascent RNP complexes during the maturation of virus particles.We constructed a reporter influenza A/Puerto Rico/8/1934 virus expressing truncated 124aa N-terminal NS1 protein fused to a luciferase reporter sequence (NanoLuc) without signal peptide. The reproduction activity of the vector correlated well with the luminescent activity in the lysates of infected cell cultures or mouse respiratory organ suspensions. Surprisingly, we found that luciferase enzymatic activity was present not only in the intracellular compartments but also in cell culture supernatants as well as in the sera or bronchiolar lavages of infected mice. This fact allowed us to formulate a working hypothesis about the extracellular delivery mechanism of the NS1 protein. To test this idea, we conducted co-transfection experiments in Vero cells with different combinations of plasmids encoding influenza genomic segments and chimeric NS1-NanoLuc encoding plasmid. We found that the emergence of the luciferase reporter in the extracellular compartment was promoted by the formation of the ribonucleoprotein complex (RNP) from the co-transfection of plasmids expressing PB1, PB2, PA, and NP proteins. Therefore, influenza NS1 protein may be delivered to the extracellular compartment together with the nascent RNP complexes during the maturation of virus particles
Риск развития Clostridium difficile инфекции, связанный с применением различных групп антибиотиков и их сочетаний, у детей в онкологическом стационаре
Get PDFPatients in pediatric oncological hospitals are at risk of developing a Clostridium difficile infection. The purpose of this study was to determine the risk of developing a Clostridium difficile infection in patients who are treated with antibiotics of different classes and their combinations by way of a retrospective analysis of 122 patient records. It was shown that the administration of antibacterial chemotherapeutic drugs that belong to the classes of nitrofurans (enterofuryl), sulfonamides (biseptol), cephalosporins, and macrolides/azalides significantly increased the risk of developing a Clostridium difficile infection in pediatric patients. On the contrary, treatment with antibiotics of different classes, such as linezolid, colistin, and metronidazole, significantly reduced the risk of developing a Clostridium difficile infection. The use of penicillins, aminoglycosides, fluoroquinolones, glycopeptides, and carbapenems was not associated with the risk of developing a Clostridium difficile infection in pediatric patients. The administration of one or two antimicrobial drugs of different classes increased the risk of developing a Clostridium difficile infection while a combination of three different types of antimicrobial drugs lowered the rate of this infection in pediatric patients.Пациенты детского онкологического стационара находятся в группе риска развития Clostridium difficile инфекции. Цель данного исследования состояла в определении степени риска развития Clostridium difficile инфекции в детском онкологическом стационаре при применении различных групп антибиотиков и их сочетаний. В результате было показано, что применение антибактериальных химиотерапевтических препаратов, принадлежащих к группам нитрофуранов (энтерофурил), сульфаниламидов (бисептол), цефалоспоринов и макролидов/азалидов, достоверно повышало риск развития Clostridium difficile инфекции у детей – пациентов стационара. Применение таких антибиотиков, как линезолид, колистин и метронидазол, достоверно снижало риск развития Clostridium difficile инфекции. Применение пенициллинов, аминогликозидов, фторхинолонов, гликопептидов, карбопенемов не было связано с риском развития Clostridium difficile инфекции у детей, находящихся на лечении в онкологическом стационаре. Применение одного или двух антибактериальных химиотерапевтических препаратов, принадлежащих к разным группам, увеличивало риск развития Clostridium difficile инфекции по сравнению с применением препаратов трех групп
The impact of the global distribution of bats on mortality in COVID-19 patients
Get PDFSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in November 2019 in China and quickly spread throughout the world causing a disease named COVID-19. An analysis of the epidemiological data on morbidity and mortality caused by SARS-CoV-2 shows that, in some countries, namely Belgium, UK, France, Italy, the Netherlands, and Spain, an increased case fatality rate (CFR) was noticed compared to the rest of the world. The CFR, calculated as the number of deaths from the total number of the cases, ranges in these countries from 10.22% to 15.8% according to the Center for Evidence-Based Medicine (CEBM). At the same time, in the countries of Central and Northern Europe, this parameter varies between 3.78% and 4.94%. This significant heterogeneity in CFR between countries has not been given a convincing explanation yet. It was found that the precursor of SARS-CoV-2 is a virus circulating in bats in China. The mutations that occurred in this virus altered its receptor specificity, thereby enabling viral infection in humans. Bats are highly resistant to viral infections due to their robust interferon system and a reduced level of inflammatory reactions. Viruses replicate in these animals up to high titers without any substantial harm to their health. As a result, bats represent a large reservoir of viruses with the potential to infect other animals, including humans. The infection of people with bat (or human) betacoronaviruses can lead to the formation of memory B-cells that provide an accelerated antibody response to cross-reactive epitopes upon subsequent infection. The early emergence of neutralizing antibodies in SARS-CoV-2 patients correlates with the severity of the disease and the likelihood of a fatal outcome. The antibodydependent enhancement (ADE) of infection/disease known for various viruses, including SARS-CoV-1 and MERS-CoV, may be a possible cause of this phenomenon. In this article, we suggest a close connection between the distribution areas of bats carrying SARS-CoV-1-like viruses and the CFR from COVID-19.Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in November 2019 in China and quickly spread throughout the world causing a disease named COVID-19. An analysis of the epidemiological data on morbidity and mortality caused by SARS-CoV-2 shows that, in some countries, namely Belgium, UK, France, Italy, the Netherlands, and Spain, an increased case fatality rate (CFR) was noticed compared to the rest of the world. The CFR, calculated as the number of deaths from the total number of the cases, ranges in these countries from 10.22% to 15.8% according to the Center for Evidence-Based Medicine (CEBM). At the same time, in the countries of Central and Northern Europe, this parameter varies between 3.78% and 4.94%. This significant heterogeneity in CFR between countries has not been given a convincing explanation yet. It was found that the precursor of SARS-CoV-2 is a virus circulating in bats in China. The mutations that occurred in this virus altered its receptor specificity, thereby enabling viral infection in humans. Bats are highly resistant to viral infections due to their robust interferon system and a reduced level of inflammatory reactions. Viruses replicate in these animals up to high titers without any substantial harm to their health. As a result, bats represent a large reservoir of viruses with the potential to infect other animals, including humans. The infection of people with bat (or human) betacoronaviruses can lead to the formation of memory B-cells that provide an accelerated antibody response to cross-reactive epitopes upon subsequent infection. The early emergence of neutralizing antibodies in SARS-CoV-2 patients correlates with the severity of the disease and the likelihood of a fatal outcome. The antibodydependent enhancement (ADE) of infection/disease known for various viruses, including SARS-CoV-1 and MERS-CoV, may be a possible cause of this phenomenon. In this article, we suggest a close connection between the distribution areas of bats carrying SARS-CoV-1-like viruses and the CFR from COVID-19
Detection and identification of wheat and barley phytopathogens in the Russian Federation
Get PDFGrain export is an important branch of the food business in the Russian Federation. The countries of Europe, Asia, Africa, and South America are importers of Russian grain. Each importing country has its own requirements for the phytosanitary condition of imported products. One important requirement for importers is the absence of pathogens that can cause bacterial diseases of grain crops, such as Pectobacterium rhapontici, Rathayibacter tritici, Pseudomonas fuscovaginae, Pseudomonas syringae pvs., Acidovorax avenae subsp. avenae, Xanthomonas translucens pvs., Rathayibacter rathayi, and Pseudomonas cichorii. Reliable information on the distribution of these bacterial strains in the Russian Federation is limited. Methods for the isolation and identification of these bacterial pathogens have not been developed to date, which increases the risk of the spread of phytopathogens that could cause significant economic harm to agriculture.The purpose of this study was to isolate and identify the causative agents of bacterial diseases of wheat and barley. In order to do this, we collected samples of plant material of wheat and barley in the Rodionovo-Nesvetaysky, Myasnikovsky, Zernogradsky, Azovsky, and Martynovsky districts of the Rostov Oblast. Various bacterial strains were isolated from the obtained samples using the appropriate cultural media. The strains were tested by polymerase chain reaction (PCR) using primers designed for the 16S ribosomal RNA (PSF/PSR and 8UA/519B) and SyD1/SyD2 primers selected for the Pseudomonas syringae genome (GenBank CP047267.1) with subsequent sequencing according to the Sanger method. As a result, the following bacterial strains were isolated and identified from wheat and barley samples: Curtobacterium sp., Paenibacillus sp., Enterobacteriaceae, Pseudomonas azotoformans, P. poae, P. azotoformans, P. hibiscicola, P. fluorescens, Stenotrophomonas sp., P. syringae pv. syringae, P. syringae pv. atrofaciens, Bacillus sp., Erwinia sp., Pantoea sp., and Pantoea agglomerans.Grain export is an important branch of the food business in the Russian Federation. The countries of Europe, Asia, Africa, and South America are importers of Russian grain. Each importing country has its own requirements for the phytosanitary condition of imported products. One important requirement for importers is the absence of pathogens that can cause bacterial diseases of grain crops, such as Pectobacterium rhapontici, Rathayibacter tritici, Pseudomonas fuscovaginae, Pseudomonas syringae pvs., Acidovorax avenae subsp. avenae, Xanthomonas translucens pvs., Rathayibacter rathayi, and Pseudomonas cichorii. Reliable information on the distribution of these bacterial strains in the Russian Federation is limited. Methods for the isolation and identification of these bacterial pathogens have not been developed to date, which increases the risk of the spread of phytopathogens that could cause significant economic harm to agriculture.The purpose of this study was to isolate and identify the causative agents of bacterial diseases of wheat and barley. In order to do this, we collected samples of plant material of wheat and barley in the Rodionovo-Nesvetaysky, Myasnikovsky, Zernogradsky, Azovsky, and Martynovsky districts of the Rostov Oblast. Various bacterial strains were isolated from the obtained samples using the appropriate cultural media. The strains were tested by polymerase chain reaction (PCR) using primers designed for the 16S ribosomal RNA (PSF/PSR and 8UA/519B) and SyD1/SyD2 primers selected for the Pseudomonas syringae genome (GenBank CP047267.1) with subsequent sequencing according to the Sanger method. As a result, the following bacterial strains were isolated and identified from wheat and barley samples: Curtobacterium sp., Paenibacillus sp., Enterobacteriaceae, Pseudomonas azotoformans, P. poae, P. azotoformans, P. hibiscicola, P. fluorescens, Stenotrophomonas sp., P. syringae pv. syringae, P. syringae pv. atrofaciens, Bacillus sp., Erwinia sp., Pantoea sp., and Pantoea agglomerans
Enhanced CD8+ T-cell response in mice immunized with NS1-truncated influenza virus
Get PDFInfluenza viruses with truncated NS1 protein stimulate a more intensive innate immune response compared to their wild type counterparts. Here, we investigate how the shortening of the NS1 protein influence the immunogenicity of the conserved T-cellular epitopes of influenza virus. Using flow cytometry, we showed that the intraperitoneal immunization of mice with influenza virus encoding 124 N-terminal amino acid residues of the NS1 protein (A/PR8/NS124) induced higher levels of CD8+ T-cells recognizing immunodominant (NP366-374) and sub-immunodominant (NP161-175, NP196-210, HA323-337, HA474-483, NA427-433) epitopes compared to immunization with the virus expressing full-length NS1 (A/PR8/full NS). It is noteworthy that the response to the immunodominant influenza epitope NP366-374 was achieved with the lower immunization dose of A/PR8/NS124 virus compared to the reference wild type strain. Despite the fact that polyfunctional CD8+ effector memory T-lymphocytes simultaneously producing two (IFNγ and TNFα) or three (IFNγ, IL2, and TNFα) cytokines prevailed in the immune response to both viruses, the relative number of such T-cells was higher in A/PR8/NS124-immunized mice. Furthermore, we have found that polyfunctional populations of lymphocytes generated upon the immunization of mice with the mutant virus demonstrated an increased capacity to produce IFNγ compared to the corresponding populations derived from the A/PR8/full NS-immunized mice. Therefore, immunization with the attenuated influenza virus encoding truncated NS1 protein ensures a more potent CD8+ T-cell immune response.Influenza viruses with truncated NS1 protein stimulate a more intensive innate immune response compared to their wild type counterparts. Here, we investigate how the shortening of the NS1 protein influence the immunogenicity of the conserved T-cellular epitopes of influenza virus. Using flow cytometry, we showed that the intraperitoneal immunization of mice with influenza virus encoding 124 N-terminal amino acid residues of the NS1 protein (A/PR8/NS124) induced higher levels of CD8+ T-cells recognizing immunodominant (NP366-374) and sub-immunodominant (NP161-175, NP196-210, HA323-337, HA474-483, NA427-433) epitopes compared to immunization with the virus expressing full-length NS1 (A/PR8/full NS). It is noteworthy that the response to the immunodominant influenza epitope NP366-374 was achieved with the lower immunization dose of A/PR8/NS124 virus compared to the reference wild type strain. Despite the fact that polyfunctional CD8+ effector memory T-lymphocytes simultaneously producing two (IFNγ and TNFα) or three (IFNγ, IL2, and TNFα) cytokines prevailed in the immune response to both viruses, the relative number of such T-cells was higher in A/PR8/NS124-immunized mice. Furthermore, we have found that polyfunctional populations of lymphocytes generated upon the immunization of mice with the mutant virus demonstrated an increased capacity to produce IFNγ compared to the corresponding populations derived from the A/PR8/full NS-immunized mice. Therefore, immunization with the attenuated influenza virus encoding truncated NS1 protein ensures a more potent CD8+ T-cell immune response
Hypothesis: daptomycin permeabilizes membranes by forming self‑assembled nanotubes
Get PDFDaptomycin is the only lipopeptide antibiotic that is widely used in clinical practice. It was discovered by Eli Lilly and then studied and commercialized by Cubist Pharmaceuticals in 2003. Although this antibiotic has been used for 17 years, the debate over its mechanism of action is ongoing. In this paper, we discuss the different hypotheses on the mode of action of this antibiotic with a primary focus on the bacterial membrane permeabilization as the main mechanism of action. By comparing the experimental data on the oligomerization of daptomycin in membranes with properties of self-assembling cyclic peptides, we conclude that the structure of daptomycin oligomer should resemble the structures of peptide nanotubes that serve as ion channels in membranes.Daptomycin is the only lipopeptide antibiotic that is widely used in clinical practice. It was discovered by Eli Lilly and then studied and commercialized by Cubist Pharmaceuticals in 2003. Although this antibiotic has been used for 17 years, the debate over its mechanism of action is ongoing. In this paper, we discuss the different hypotheses on the mode of action of this antibiotic with a primary focus on the bacterial membrane permeabilization as the main mechanism of action. By comparing the experimental data on the oligomerization of daptomycin in membranes with properties of self-assembling cyclic peptides, we conclude that the structure of daptomycin oligomer should resemble the structures of peptide nanotubes that serve as ion channels in membranes
Выявление и идентификация возбудителей бактериальных болезней пшеницы и ячменя в России
Get PDFGrain export is an important branch of the food business in the Russian Federation. The countries of Europe, Asia, Africa, and South America are importers of Russian grain. Each importing country has its own requirements for the phytosanitary condition of imported products. One important requirement for importers is the absence of pathogens that can cause bacterial diseases of grain crops, such as Pectobacterium rhapontici, Rathayibacter tritici, Pseudomonas fuscovaginae, Pseudomonas syringae pvs., Acidovorax avenae subsp. avenae, Xanthomonas translucens pvs., Rathayibacter rathayi, and Pseudomonas cichorii. Reliable information on the distribution of these bacterial strains in the Russian Federation is limited. Methods for the isolation and identification of these bacterial pathogens have not been developed to date, which increases the risk of the spread of phytopathogens that could cause significant economic harm to agriculture.The purpose of this study was to isolate and identify the causative agents of bacterial diseases of wheat and barley. In order to do this, we collected samples of plant material of wheat and barley in the Rodionovo-Nesvetaysky, Myasnikovsky, Zernogradsky, Azovsky, and Martynovsky districts of the Rostov Oblast. Various bacterial strains were isolated from the obtained samples using the appropriate cultural media. The strains were tested by polymerase chain reaction (PCR) using primers designed for the 16S ribosomal RNA (PSF/PSR and 8UA/519B) and SyD1/SyD2 primers selected for the Pseudomonas syringae genome (GenBank CP047267.1) with subsequent sequencing according to the Sanger method. As a result, the following bacterial strains were isolated and identified from wheat and barley samples: Curtobacterium sp., Paenibacillus sp., Enterobacteriaceae, Pseudomonas azotoformans, P. poae, P. azotoformans, P. hibiscicola, P. fluorescens, Stenotrophomonas sp., P. syringae pv. syringae, P. syringae pv. atrofaciens, Bacillus sp., Erwinia sp., Pantoea sp., and Pantoea agglomerans.Экспорт зерна представляет собой важную статью продовольственного бизнеса в России. Импортерами российского зерна являются страны Европы, Азии, Африки и Южной Америки. Каждая страна-импортер предъявляет свои требования к фитосанитарному состоянию ввозимой продукции. Важным требованием импортеров является отсутствие в партиях зерна таких возбудителей бактериальных болезней зерновых культур, как Pectobacterium rhapontici, Rathayibacter tritici, Pseudomonas fuscovaginae, Pseudomonas syringae pvs., Acidovorax avenae subsp. avenae, Xanthomonas translucens pvs., Rathayibacter rathayi и Pseudomonas cichorii. Достоверная информация о распространении данных видов бактерий на территории Российской Федерации ограничена. Методы выявления и идентификации возбудителей бактериозов на сегодняшний день не разработаны, что повышает риск распространения фитопатогенов, способных нанести существенный экономический вред сельскому хозяйству.Цель данного исследования состояла в выявлении и идентификации возбудителей бактериальных болезней пшеницы и ячменя. Для этого нами был проведен сбор образцов растительного материала пшеницы и ячменя в Родионово-Несветайском, Мясниковском, Зерноградском, Азовском и Мартыновском районах Ростовской области. Представители различных штаммов бактерий были выделены из полученных образцов с использованием соответствующих питательных сред. Тестирование штаммов было проведено методом полимеразно-цепной реакции (ПЦР) с использованием праймеров, разработанных для участка 16S рибосомальной РНК (PSF/PSR и 8UA/519B), и праймеров SyD1/SyD2, подобранных для участка генома Pseudomonas syringae (GenBank CP047267.1), с последующим секвенированием по Сэнгеру.В результате из проб пшеницы и ячменя были выделены и идентифицированы штаммы следующих бактерий: Curtobacterium sp., Paenibacillus sp., Enterobacteriaceae, Pseudomonas azotoformans, P. poae, P. azotoformans, P. hibiscicola, P. fluorescens, Stenotrophomonas sp., P. syringae pv. syringae, P. syringae pv. atrofaciens, Bacillus sp., Erwinia sp., Pantoea sp. и Pantoea agglomerans
The risk of developing a Clostridium difficile infection from the administration of different classes of antibiotics and their combinations to children in an oncological hospital
Get PDFPatients in pediatric oncological hospitals are at risk of developing a Clostridium difficile infection. The purpose of this study was to determine the risk of developing a Clostridium difficile infection in patients who are treated with antibiotics of different classes and their combinations by way of a retrospective analysis of 122 patient records. It was shown that the administration of antibacterial chemotherapeutic drugs that belong to the classes of nitrofurans (enterofuryl), sulfonamides (biseptol), cephalosporins, and macrolides/azalides significantly increased the risk of developing a Clostridium difficile infection in pediatric patients. On the contrary, treatment with antibiotics of different classes, such as linezolid, colistin, and metronidazole, significantly reduced the risk of developing a Clostridium difficile infection. The use of penicillins, aminoglycosides, fluoroquinolones, glycopeptides, and carbapenems was not associated with the risk of developing a Clostridium difficile infection in pediatric patients. The administration of one or two antimicrobial drugs of different classes increased the risk of developing a Clostridium difficile infection while a combination of three different types of antimicrobial drugs lowered the rate of this infection in pediatric patients.Patients in pediatric oncological hospitals are at risk of developing a Clostridium difficile infection. The purpose of this study was to determine the risk of developing a Clostridium difficile infection in patients who are treated with antibiotics of different classes and their combinations by way of a retrospective analysis of 122 patient records. It was shown that the administration of antibacterial chemotherapeutic drugs that belong to the classes of nitrofurans (enterofuryl), sulfonamides (biseptol), cephalosporins, and macrolides/azalides significantly increased the risk of developing a Clostridium difficile infection in pediatric patients. On the contrary, treatment with antibiotics of different classes, such as linezolid, colistin, and metronidazole, significantly reduced the risk of developing a Clostridium difficile infection. The use of penicillins, aminoglycosides, fluoroquinolones, glycopeptides, and carbapenems was not associated with the risk of developing a Clostridium difficile infection in pediatric patients. The administration of one or two antimicrobial drugs of different classes increased the risk of developing a Clostridium difficile infection while a combination of three different types of antimicrobial drugs lowered the rate of this infection in pediatric patients
Влияние глобального распределения летучих мышей на смертность у пациентов с COVID-19
Get PDFSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in November 2019 in China and quickly spread throughout the world causing a disease named COVID-19. An analysis of the epidemiological data on morbidity and mortality caused by SARS-CoV-2 shows that, in some countries, namely Belgium, UK, France, Italy, the Netherlands, and Spain, an increased case fatality rate (CFR) was noticed compared to the rest of the world. The CFR, calculated as the number of deaths from the total number of the cases, ranges in these countries from 10.22% to 15.8% according to the Center for Evidence-Based Medicine (CEBM). At the same time, in the countries of Central and Northern Europe, this parameter varies between 3.78% and 4.94%. This significant heterogeneity in CFR between countries has not been given a convincing explanation yet. It was found that the precursor of SARS-CoV-2 is a virus circulating in bats in China. The mutations that occurred in this virus altered its receptor specificity, thereby enabling viral infection in humans. Bats are highly resistant to viral infections due to their robust interferon system and a reduced level of inflammatory reactions. Viruses replicate in these animals up to high titers without any substantial harm to their health. As a result, bats represent a large reservoir of viruses with the potential to infect other animals, including humans. The infection of people with bat (or human) betacoronaviruses can lead to the formation of memory B-cells that provide an accelerated antibody response to cross-reactive epitopes upon subsequent infection. The early emergence of neutralizing antibodies in SARS-CoV-2 patients correlates with the severity of the disease and the likelihood of a fatal outcome. The antibodydependent enhancement (ADE) of infection/disease known for various viruses, including SARS-CoV-1 and MERS-CoV, may be a possible cause of this phenomenon. In this article, we suggest a close connection between the distribution areas of bats carrying SARS-CoV-1-like viruses and the CFR from COVID-19.Появившись в ноябре 2019 г. в Китае, коронавирус SARS-CoV-2 (severe acute respiratory syndrom – coronavirus 2) быстро распространился по всему миру, вызывая заболевание, получившее название COVID-19. Анализ эпидемиологических данных по заболеваемости и смертности, вызванной SARS-CoV-2, показывает, что в отдельных странах, а именно в Бельгии, Великобритании, Франции, Италии, Нидерландах, Испании, наблюдается повышенная смертность по сравнению с другими странами. Коэффициент летальности, рассчитываемый как число смертельных случаев от общего числа зараженных, по данным Центра доказательной медицины CEBM (Centre for Evidence-Based Medicine), в этих странах составляет от 10.22% до 15.80%. В то же время в Центральной и Северной Европе этот показатель составляет от 3.78% до 4.94%. Причины такой неоднородности в показателе смертности для перечисленных стран пока не получили убедительного объяснения. Установлено, что предшественником SARS-CoV-2 является вирус, циркулирующий в Китае в летучих мышах, в котором произошли мутации, изменившие его рецепторную специфичность и сделавшие возможным инфицирование людей. Летучие мыши обладают высокой устойчивостью к вирусным инфекциям за счет мощной системы интерферонового ответа и сниженного уровня воспалительных реакций. Вирусы реплицируются в этих животных до высоких титров, не принося существенного вреда их здоровью. В результате огромное множество существующих в природе летучих мышей является переносчиком вирусов, заражая животных и людей. Заражение людей бетакоронавирусами летучих мышей (или человека) может приводить к образованию у них В-клеток памяти, которые обеспечивают ускоренный антительный ответ к перекрестным эпитопам при последующей инфекции. Раннее появление антител у больных SARS-CoV-2 коррелирует с тяжестью патологии и вероятностью летального исхода. Возможной причиной этого явления может быть реакция антителозависимого усиления инфекции/заболевания ADE (antibody-dependent enhancement), известная для различных вирусов, включая SARS-CoV-1 и MERS-CoV. В данной статье мы предполагаем наличие связи между ареалами распространения летучих мышей, являющихся переносчиками SARS-CoV-1-родственных вирусов, и уровнем смертности при COVID-19