Assessment of the role of microorganisms of respiratory tract in patients with progressive acute respiratory viral infections

The article presents the review of literature for the period from 1987 till 2012. It has been shown that the spread of acute respiratory viral infections (ARI) and the incidence of complications is of great social and economic importance worldwide. Therefore, the identification of etiological factors and associated development of ARI is an urgent task for practical health care. It is of great importance to determine both the type of pathogen and the presence of its pathogenic factors. The etiological agent of bacterial complications of ARI becomes Moraxella catarrhalis, featuring a large set of markers of virulence. In the development of the pathological process in the respiratory tract, adhesins, a number of enzymes and toxins produced by M.catarrhalis are important. It allows to persist and multiply in the body of the patient. Dangerous strains of M.catarrhalis, resistant to (3-lactam antibiotics and characterized by multiresistance greatly reduce the effectiveness of the therapy. Lack of laboratory studies in acute inflammatory diseases of the respiratory tract leads to the reduction of the etiological interpretation of these diseases, inadequate etiotropic treatment and as a consequence — the development of complications that reduces the effectiveness of therapy. In conclusion it is necessary to improve the system of microbiological diagnostics and tactics of treatment of ARI patients

The importance of pathogenicity factors of some Streptococcus spp. And klebsiella spp. And determining their etiological role in the inflammatory processes of the respiratory tract [ЗНАЧЕНИЕ ФАКТОРОВ ПАТОГЕННОСТИ НЕКОТОРЫХ ВИДОВ СТРЕПТОКОККОВ И КЛЕБСИЕЛЛ ПРИ ОПРЕДЕЛЕНИИ ИХ ЭТИОЛОГИЧЕСКОЙ РОЛИ В РАЗВИТИИ ВОСПАЛИТЕЛЬНЫХ ПРОЦЕССОВ РЕСПИРАТОРНОГО ТРАКТА]

Together with the known pathogens of inf lammatory processes of the respiratory tract in clinical practice are often found representatives of Streptococcus and Klebsiella, previously considered commensals of the mucous membranes of the upper respiratory tract. The exchange of genetic information facilitates the transfer of virulence factors between strains not only within the species but also within the genus. In such cases, the acquisition of virulence genes by non-pathogenic species from representatives of pathogenic species contributes to the manifestation of previously not typical properties. Therefore, the aim of the research was to study the virulence of opportunistic Streptococcus spp. and Klebsiella spp. in inf lammatory processes of the respiratory tract and substantiate their etiological role in the development of the disease. We studied 220 strains of Streptococcus spp. and 97 strains of Klebsiella spp., isolated from patients with inf lammatory processes in the respiratory tract and from healthy individuals. Strains of Streptococcus spp. were investigated for the presence of virulence genes: sagA, lmb, fap1, ply, lytA. Strains of Klebsiella spp. were examined for the presence of virulence genes: MrkD, magA, kfu. The phenotypic marker of lmb gene expression in Streptococcus and MrkD gene in Klebsiella was the indicator of adhesion of isolated strains to buccal epithelial cells. Expression of the fap1 gene was evaluated in a phenotypic biofilm formation test. In individuals with upper respiratory tract inf lammation, the most common types of streptococci were: S. mitis, S. anginosus, and S. oralis. Strains of these species isolated from inf lammatory processes in the upper respiratory tract had 2-4 times greater adhesiveness than strains isolated from healthy individuals. Phenotypic determination of the ability to biofilm formation showed that strains of Streptococcus containing the fap1 gene formed a dense biofilm in contrast to strains without the fap1 gene. K. oxytoca strains isolated from people with sinusitis had mrkd, magA, and kfu virulence genes that are characteristic of K. pneumoniae strains. In phenotypic tests, it was found that the value of the adhesion index in K. oxytoca strains isolated from patients is 4 times higher than in strains of this species isolated from healthy individuals. Thus, to confirm the etiological role of an opportunistic microorganism in the development of the infectious process, it is necessary to be guided by data on the genetic and phenotypic markers of virulence of the isolated strain. © 2020 Saint Petersburg Pasteur Institute. All rights reserved

Значение факторов патогенности некоторых видов стрептококков и клебсиелл при определении их этиологической роли в развитии воспалительных процессов респираторного тракта

Together with the known pathogens of inflammatory processes of the respiratory tract in clinical practice are often found representatives of Streptococcus and Klebsiella, previously considered commensals of the mucous membranes of the upper respiratory tract. The exchange of genetic information facilitates the transfer of virulence factors between strains not only within the species but also within the genus. In such cases, the acquisition of virulence genes by nonpathogenic species from representatives of pathogenic species contributes to the manifestation of previously not typical properties. Therefore, the aim of the research was to study the virulence of opportunistic Streptococcus spp. and Klebsiella spp. in inflammatory processes of the respiratory tract and substantiate their etiological role in the development of the disease. We studied 220 strains of Streptococcus spp. and 97 strains of Klebsiella spp., isolated from patients with inflammatory processes in the respiratory tract and from healthy individuals. Strains of Streptococcus spp. were investigated for the presence of virulence genes: sagA, lmb, fapl, ply, lytA. Strains of Klebsiella spp. were examined for the presence of virulence genes: MrkD, magA, kfu. The phenotypic marker of lmb gene expression in Streptococcus and MrkD gene in Klebsiella was the indicator of adhesion of isolated strains to buccal epithelial cells. Expression of the fapl gene was evaluated in a phenotypic biofilm formation test. In individuals with upper respiratory tract inflammation, the most common types of strepto -cocci were: S. mitis, S. anginosus, and S. oralis. Strains of these species isolated from inflammatory processes in the upper respiratory tract had 2-4 times greater adhesiveness than strains isolated from healthy individuals. Phenotypic determination of the ability to biofilm formation showed that strains of Streptococcus containing the fapl gene formed a dense biofilm in contrast to strains without the fapl gene. K. oxytoca strains isolated from people with sinusitis had mrkd, magA, and kfu virulence genes that are characteristic of K. pneumoniae strains. In phenotypic tests, it was found that the value of the adhesion index in K. oxytoca strains isolated from patients is 4 times higher than in strains of this species isolated from healthy individuals. Thus, to confirm the etiological role of an opportunistic microorganism in the development of the infectious process, it is necessary to be guided by data on the genetic and phenotypic markers of virulence of the isolated strain.Наряду с известными возбудителями воспалительных процессов респираторного тракта в клинической практике часто встречаются представители стрептококков и клебсиелл, ранее считавшиеся комменсалами слизистых оболочек верхних дыхательных путей. Обмен генетической информацией способствует передаче детерминант вирулентности между штаммами не только в пределах вида, но и рода. В таких случаях приобретение генов вирулентности от представителей патогенных видов способствует проявлению непатогенными стрептококками ранее не присущих им свойств. Поэтому целью исследования стало изучение вирулентности условно-патогенных стрептококков и клебсиелл при воспалительных процессах респираторного тракта и обоснование их этиологической роли в развитии заболеваний. Изучены 220 штаммов Streptococcus spp. и 97 штаммов Klebsiella spp., выделенных от пациентов с воспалительными процессами в респираторном тракте и от здоровых лиц. Стрептококки исследовали на наличие генов вирулентности sagA, lmb, fap1, ply, lytA. Штаммы Klebsiella spp. исследовали на наличие генов вирулентности MrkD, magA, kfu. Фенотипическим маркером экспрессии гена lmb у стрептококков и гена MrkD у клебсиелл служил показатель адгезии выделенных штаммов к клеткам буккального эпителия. Экспрессию гена fap1 оценивали в фенотипическом тесте биопленкообразования. У лиц с воспалительными процессами верхних дыхательных путей наиболее часто присутствовали виды стрептококков: S. mitis, S. anginosus, S. oralis. Штаммы указанных видов, выделенные при воспалительных процессах в верхних дыхательных путях, обладали в 2-4 раза большей адгезивностью, чем штаммы, выделенные от здоровых лиц. Фенотипическое определение способности к биопленкообразованию показало, что штаммы стрептококков, содержащие ген fap1, формировали выраженную биопленку в отличие от штаммов, не имеющих гена fap1. Штаммы K. oxytoca, выделенные от людей с гайморитом, имели гены вирулентности MrkD, magA, kfu, которые характерны для штаммов K. pneumoniae. В фенотипических тестах установлено, что значение индекса адгезии у штаммов K. oxytoca, выделенных от больных, в 4 раза выше, чем у штаммов этого вида, выделенных от здоровых лиц. Таким образом, для подтверждения этиологической роли условно-патогенного микроорганизма в развитии инфекционного процесса необходимо руководствоваться данными о генетических и фенотипических маркерах вирулентности выделенного штамма

Antibiotic resistance of moraxella catarrhalis strains isolated from patients with complicated acute respiratory viral infections and other acute respiratory diseases

In recent years, acute respiratory viral infections (ARVIs) and other acute respiratory diseases (ARDs) have acquired some new characteristics of the disease course. The structure of complications has changed, in particular, such complications as community-acquired pneumonia (CAP) and lesions to the upper respiratory tract have become significantly more common. CAP remains one of the main causes of death in patients with ARVIs and other acute respiratory infections due to bacterial resistance to antibiotics. Objective. To assess drug sensitivity of Moraxella catarrhalis strains isolated from patients with complicated ARVIs or ARDs. Materials and methods. Drug susceptibility assessment was performed using the disk diffusion method (DDM) and gradient diffusion method (E-test). The production of β-lactamases was evaluated using nitrocephine, a chromogenic substrate. Results. Isolated strains of M. catarrhalis were resistant to third-generation cephalosporins and sensitive to fourth-and fifth-generation cephalosporins. More than 70% of M. catarrhalis strains developed resistance to macrolides; 8% of strains were resistant to amoxiclav. All isolated M. catarrhalis strains were sensitive to respiratory fluoroquinolones, carbapenems, and ampicillin-sulbactam. © 2021, Dynasty Publishing House. All rights reserved

Clinical and laboratory profile of patients with COVID-19 admitted to hospital in Moscow between may and july 2020

Objective. Data of the clinical picture forms of the disease, management and diagnostic capabilities of patients with COVID-19 continue to be studied. Our study presents results from the analysis of clinical and laboratory parameters of patients with COVID-19 in the period May-June 2020, who were treated in an infectious diseases hospital in Moscow. Patients and methods. The analytical cohort included 444, 198 men, 246 women aged 18 to 95 years, who were identified with SARS-CoV-2 RNA. The severity of the disease was determined in accordance with the temporary clinical recommendations (version 6 effective April 28, 2020), NEWS. Results. The study of the clinical picture showed the variability of the spectrum of clinical manifestations of COVID-19. The most common symptoms were fever, weakness, myalgia, dry cough, shortness of breath, diarrhea. The severity of the infection was not associated with the patient's gender, but was significantly correlated with age and the presence of comorbid status, which included chronic lung diseases, obesity, diabetes mellitus, and cardiovascular diseases. Observations of patients with severe and extremely severe course revealed characteristic laboratory markers of severity. The main method of etiological diagnosis was the RT-PCR method for detecting SARS-CoV-2 RNA in the nasopharyngeal secret. To verify COVID-19, we used an additional PCR method, fecal testing for the detection of SARS-CoV-2 RNA. © 2021, Dynasty Publishing House. All rights reserved