First detection of influenza A virus subtypes H1N1 and H3N8 in the Antarctic region: King George Island, 2023.

RELEVANCE: Influenza A virus is characterized by a segmented single-stranded RNA genome. Such organization of the virus genome determines the possibility of reassortment, which can lead to the emergence of new virus variants. The main natural reservoir of most influenza A virus subtypes are wild waterfowl. Seasonal migrations gather waterfowl from all major migration routes to nesting areas near the northern and southern polar circles. This makes intercontinental spread of influenza A viruses possible. Objective ‒ to conduct molecular genetic monitoring and study the phylogenetic relationships of influenza A virus variants circulating in Antarctica in 2023. MATERIALS AND METHODS: We studied 84 samples of biological material obtained from birds and marine mammals in April‒May 2023 in coastal areas of Antarctica. For 3 samples, sequencing was performed on the Miseq, Illumina platform and phylogenetic analysis of the obtained nucleotide sequences of the influenza A virus genomes was performed. RESULTS: The circulation of avian influenza virus in the Antarctic region was confirmed. Heterogeneity of the pool of circulating variants of the influenza A virus (H3N8, H1N1) was revealed. Full-length genomes of the avian influenza virus were sequenced and posted in the GISAID database (EPI_ISL_19032103, 19174530, 19174467). CONCLUSION: The study of the genetic diversity of influenza A viruses circulating in the polar regions of the Earth and the identification of the conditions for the emergence of new genetic variants is a relevant task for the development of measures to prevent biological threats.

[MULTI-LEVEL EVALUATION OF BIOSOCIAL RISK FACTORS OF HIV-INFECTION AMONG MIGRANT WORKERS].

AIM: Multi-level evaluation by case-control method of social, sociocultural and behavioural risk factors of HIV-infection spread among male migrant workers arriving to Russia from near abroad countries. MATERIALS AND METHODS: Interviews of migrants, that had appealed for medical examination for work permit, were carried out for detection of risk factors. Results of interviewing of 191 migrants with HIV-infection (case group) and 190 migrants without HIV-infection (control group) were analyzed. Methods of descriptive statistics and logistical regression were used for the analysis. RESULTS: Factors, related to dangerous sexual behavior, were leading in development of HIV-infection. Furthermore, HIV-infected migrants had inferior work and accommodation conditions, lower salary, lower subjective health evaluation, became object of xenophobia more frequently and had more previous travels into the receiving country. Factors, that reduce risk of infection and spread of HIV-infection, were detected: HIV-infection awareness, adherence to religion and legal requirements of the receiving country. Advantages and disadvantages of survey- ing during detection of HIV-infection risk factors are discussed. CONCLUSION: The same risk factors of HIV-infection spread are significant in the population of migrant workers as in the indigenous population. Factors specific for migrants, that facilitate infection spread, were also established. HIV prophylaxis system among migrants should be based on prevention and correction of risk factors detected in the study and enhancement of factors, that cause preventive effect.

[Contemporary view on the role of bacteriophages in evolution of nosocomial strains and prophylaxis of healthcare associated infections].

One of the actual problems of contemporary healthcare are healthcare associated infections (HAI). An important aspect of study of HAI problem is the study of evolution of hospital strains causing HAI. The knowledge accumulated to date in the field of bacteria genetics gives evidence on the significant role of phages in the mechanism of virulence obtaining by pathogenic and opportunistic microorganisms. The studies of the authors of this article show that bacteriophages may play a significant role in the formation of virulent properties in hospital conditions that in different hospitals with participation of phages form virulent and antibiotic resistant hospital strains of HAI causative agents. At the same time bacteriophages are effective means for HAI therapy and prophylaxis. Under the condition of mass and irrational use of antibiotics, HAI causative agents form multiple resistance to the existing antibacterial preparations. In this regard bacteriophages as antimicrobial agents become especially actual. To date in Russian and foreign literature considerable material has been accumulated that shows high effectiveness of bacteriophages under the conditions of rational use. The aim of this review is to evaluate contemporary achievements in the field of study of bacteriophage role in evolution of hospital strains and therapy and prophylaxis of healthcare associated infections.

[Genetic variety of Acinetobacter baumannii in an intensive care unit for burn patients].

The genetic structure of A. baumannii hospital isolates, formed in the course of 2002 - 2004 in an intensive care unit for burn patients (St. Petersburg) was studied. The prolonged circulation of only some clonal strains was shown, 35% of the isolates belonged to dominating strains. Phenotypically, all cultures were characterized by resistance to the preparations of the cephalosporin row and gentamicin. The presence of class 1 integron with variable segment sized 2.5 kbp was found in the genotype of four isolates with the use the polymerase chain reaction. The restriction analysis revealed its similarity with integron, detected earlier (in 1989 - 2001 ) in A. baumannii in European hospitals abroad.

[The effect of silver sulfadiazine on Acinetobacter baumannii strains isolated in burn units].

The genotype structure and silver sulfadiazine (SDS) resistance of a number of Acinetobacter baumanii strains that circulated for a prolonged period of time in burn UCUs were studied. The most resistant strain (SDS MIC 50 mcg/ml) contained a class 1 integron with the gene of sulfonamides resistance (sul1) in its genome. Possible reasons for selection of the multiple resistance among Acinetobacter spp. in burn units are discussed.

[Mode of the rational use of Pseudomonas aeruginosa bacteriophages in therapeutic and epidemic control practice]. / Puti ratsional'nogo ispol'zovaniia sinegnoinykh bakteriofagov v lechebnoi i protivoépidemicheskoi praktike.

Ecological aspects of the circulation of P. aeruginosa and P. aeruginosa bacteriophages under hospital conditions were under study. The statement concerning the formation of triple parasitic systems was put forward. The influence of these systems on the formation of phage and antibiotic resistance in P. aeruginosa hospital strains was studied. Spontaneous circulation of faintly virulent phages taking part in the formation of triple parasitic systems was shown not to ensure the elimination of P. aeruginosa hospital strains in clinics. Construction of highly virulent phages adapted to local P. aeruginosa strains was the only way of ensuring the protection of patients. Theoretical and practical approaches to the use of highly active bacteriophages for controlling P. aeruginosa infection were substantiated. The realization of these approaches resulted in achieving not only a clinical, but also essential epidemic control effect in cases of purulent septic infections caused by P. aeruginosa (a decreased frequentcy of hospital infections from 40.8% to 8.93%).