We conducted a series of polymerase chain reactions (PCRs) in order to detect bacteria (7 species) and viruses (17 species) in middle ear fluid (MEF) and nasopharynx (Nph) of children with acute otitis media (AOM; n=179). Bacterial and viral nucleic acids were detected in MEF of 78.8% and 14.5% patients, respectively. The prevalence was as follows: Streptococcus pneumoniae, 70.4%; Haemophilus influenzae, 17.9%; Staphylococcus aureus, 16.8%; Streptococcus pyogenes, 12.3%; Moraxella catarrhalis, 9.5%; rhinovirus, 9.5%; and adenovirus, 3.4%. The overall rate of PCR-positive specimens for bacterial pathogens was 2.6 times higher, compared to culture results. The rate of PCR-positive results and the distribution of pathogens in the Nph were similar to those in the MEF. Nph PCR results had variable positive predictive values and high negative predictive values in predicting MEF findings. Our results indicate that Nph PCR could be a practical tool for examining respiratory pathogens in children with acute infections.

Цель исследования -изучить закономерности, свойственные эпидемическому процессу COVID-19, в условиях мегаполиса, в фазах подъёма, стабилизации и снижения заболеваемости, а также оценить эффективность противоэпидемических мероприятий. Материал и методы. Проведено комплексное изучение распространения SARS-CoV-2 в Москве с использованием эпидемиологического, молекулярно-генетического и статистического методов исследования в период пандемии COVID-19. Результаты и обсуждение. Показано, что применение максимально жёстких организационно-ограничительных мер в масштабах Москвы, обеспечивающих разрыв механизма передачи SARS-CoV-2, и высокая дисциплина населения по исполнению режима самоизоляции позволили не допустить экспоненциального роста заболеваемости COVID-19. Анализ динамики выявления новых случаев COVID-19 показал, что эффект от применения мер по разобщению и режима самоизоляции в условиях мегаполиса наступает через временной промежуток, равный 3,5 инкубационного периода, при его максимальной длительности 14 дней. Установлено, что показатель частоты определения РНК SARS-CoV-2 среди условно здорового населения и его динамика -важные параметры мониторинга, особенно на фазах роста и стабилизации заболеваемости COVID-19, позволяющие в перспективе 1-2 инкубационных периодов (14-28 дней) прогнозировать развитие эпидемиологической ситуации. Общий коэффициент летальности, рассчитанный за период наблюдения (06.03.2020-23.06.2020) в Москве, составил 1,73%. Заключение. В результате проведённого эпидемиологического анализа ситуации с COVID-19 в Москве определены некоторые закономерности распространения SARS-CoV-2 и оценена эффективность противоэпидемических мероприятий, направленных на разрыв механизма передачи возбудителя.

A b s t r a c tUsing sequences of mobile genetic elements in order to mark polymorphic sites in their insertion might be the most effective approach to identify specific features of gene pools of different groups of organisms and control their dynamics, which is especially important in dealing with agricultural species. Sireviruses (Pseudoviridae) one of the oldest LTR-retrotransposons are widespread throughout the plant kingdom. SIRE-1 is one of the largest and most detailed studied retrotransposon. Its analysis showed that insertions of the retroelement (particularly in the genome of maize) have occurred recently. We studied the polymorphism of DNA fragments flanked by LTRretrotransposon SIRE-1 (IRAP-PCR markers) in the genomes of different taxonomic groups. The objects of our study were Triticum aestivum (Moscovskaya 39, Mironovskaya 808, Omskaya 36 varieties), Glycine soja (five wild populations of Primorskii region of Russia) and G. max (China), as well as representatives of the factory and indigenous breeds of cattle -Black-and-White cattle improved by Holstein cattle, Ayrshire, Yakut and Red Estonian cattle (97 animals in total). A terminal site of SIRE-1 was chosen as primer in IRAP-PCR (GCA-GTT-ATG-CAA-GTG-GGA-TCA-GCA). The data indicate that the multiloci genotyping by IRAP-PCR using retrotransposon LTR SIRE-1 as a marker reliably differentiates not only representatives of the monocotyledonous and dicotyledonous plants, but also their varieties. Spectrum of DNA fragments (13 to 16 depending on the breed) obtained in studies different breeds of cattle using IRAP-PCR markers was in the length range of 330-1470 bp. The highest polymorphism of DNA fragments was observed in the middle part of the spectrum (760-980 bp) in Ayrshire and Black-and-White cows. According to the obtained dendrogram one of the groups of Black-and-White cows and Ayrshire cattle were closer to each other, while the other with Red Estonian and Yakut cattle became isolated in a separate subcluster. Identified differences in heterogeneity in the two studied groups of Black-and-White from different farms possibly could be explained by the peculiarities of breeding work carried out or with other factors of artificial and/or natural selection. The possibility of using LTR-retrotransposons as molecular genetic markers for polyloci genotyping plants and animals is discussed.Keywords: inverted terminal sites of LTR-retrotransposons, Glycine, Triticum, Bos taurus, polymorphic information content, the share of polymorphic loci.A lot of molecular methods developed recently to mark different polymorphic region of genomes (e.g. RFLP, a restriction fragment length polymorphism, SNP, a single nucleotide polymorphism, AFLP, an amplified fragment length polymorphism, SSR-PCR, simple sequence repeats PCR, etc.) contribute to successful genotyping in both cultivated plant varieties (1-4), animal breeds (5-7). Of these markers, the mobile genetic elements have special status comparing to other structural and functional genetic elements due to their capab...

Aim: to study the etiology of severe community - acquired pneumonia (SCAP) in adults in Russian Federation. SCAP is distinguished by high mortality and socio - economic burden. Both etiology and antimicrobial resistance are essential for appropriate antibiotic choice. Materials and methods. A prospective cohort study recruited adults with confirmed diagnosis of SCAP admitted to multi - word hospitals of six Russian cities in 2014-2018. Etiology was confirmed by routine culture of blood, respiratory (sputum, endotracheal aspirate or bronchoalveolar lavage) and when appropriate, autopsy samples, urinary antigen tests (L. pneumophila serogroup 1, S. pneumoniae); real - time PCR for identification of “atypical” bacterial pathogens (M. pneumoniae, C. pneumoniae, L. pneumophila) and respiratory viruses (influenza viruses A and B, parainfluenza, human metapneumovirus, etc.) was applied. Results. Altogether 109 patients (60.6% male; mean age 50.8±18.0 years old) with SCAP were enrolled. Etiological agent was identified in 65.1% of patients, S. pneumoniae, rhinovirus, S. aureus and K. pneumoniae were the most commonly isolated pathogens (found in 43.7, 15.5, 14.1 and 11.3% of patients with positive results of microbiological investigations, respectively). Bacteriemia was seen in 14.6% of patients and most commonly associated with S. pneumoniae. Co - infection with 2 or more causative agents was revealed in 36.6% of cases. Combination of bacterial pathogens (mainly S. pneumoniae with S. aureus or/and Enterobacterales) prevailed - 57.7% of cases; associations of bacteria and viruses were identified in 38.5% of patients, different viruses - in one case. Conclusion. S. pneumoniae was the most common pathogen in adults with SCAP. A high rate of respiratory viruses (mainly rhinovirus and influenza viruses) identification both as mixt infection with bacteria and mono - infection should be taken into account.

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