The Coronaviridae family represents a broad group of RNA-containing viruses that infect humans and animals. This family belongs to the order Nidovirales and is divided into four main genera: α-CoV, β-CoV, γ-CoV and δ-CoV. It is particularly noteworthy that representatives of β-CoV have caused serious epidemics in humans, such as the outbreaks of SARS-CoV, MERS-CoV, and COVID-19 caused by SARS-CoV-2. Although the clinical manifestations of CoVs can range from mild cold-like symptoms to severe respiratory diseases, they share common features in their structure, modes of transmission, and natural reservoirs. Identifying natural reservoirs, as well as establishing intermediate hosts, is crucial for understanding the mechanisms of interspecies transmission of CoVs. These processes are often mediated by molecular interactions between viral spike (S) proteins and cellular receptors of different species, which contribute to zoonotic outbreaks. Thus, the interaction of various species and the study of these processes of viral spread, cross-species transmission, and pathogen evolution play a key role in ensuring global biological safety. Therefore, we conducted this review to summarize the data from existing studies focused on the taxonomy of CoVs, their main types, natural reservoirs, intermediate hosts, pathways of interspecies transmission, and the significance of the One Health concept as an interdisciplinary approach to monitoring, prevention and control of CoV infections at the intersection of human, animal, and environmental health. We examined databases such as PubMed, Science Direct, Web of Science, and Google Scholar to identify relevant scientific articles in English available for such a review. The aim of this work is to study the taxonomy and classification of coronaviruses, as well as to identify their natural reservoirs, intermediate hosts, and applicable control measures. A review of human and animal coronaviruses has revealed their evolutionary diversity, their main natural reservoirs, their intermediate hosts, and their interactions with cellular receptors. This information allows for a better understanding of the mechanisms by which the viruses are transmitted from animals to humans. The concept of One Health demonstrated the interconnections between human, animal and environmental factors.

Prompt determination of the etiological agent is important in an outbreak of pathogens with pandemic potential, particularly for dangerous infectious diseases. Molecular genetic methods allow for arriving at an accurate diagnosis, employing timely preventive measures, and controlling the spread of the disease-causing agent. In this study, whole-genome sequencing of three SARS-CoV-2 strains was performed using the Sanger method, which provides high accuracy in determining nucleotide sequences and avoids errors associated with multiple DNA amplification. Complete nucleotide sequences of samples, KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 were obtained, with sizes of 29.751 bp, 29.815 bp, and 29.840 bp, respectively. According to the COVID-19 Genome Annotator, 127 mutations were detected in the studied samples compared to the reference strain. The strain KAZ/Britain/2021 contained 3 deletions, 7 synonymous mutations, and 27 non-synonymous mutations, the second strain KAZ/B1.1/2021 contained 1 deletion, 5 synonymous mutations, and 31 non-synonymous mutations, and the third strain KAZ/Delta020/2021 contained 1 deletion, 5 synonymous mutations, and 37 non-synonymous mutations, respectively. The variations C241T, F106F, P314L, and D614G found in the 5′ UTR, ORF1ab, and S regions were common to all three studied samples, respectively. According to PROVEAN data, the loss-of-function mutations identified in strains KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 include 5 mutations (P218L, T716I, W149L, R52I, and Y73C), 2 mutations (S813I and Q992H), and 8 mutations (P77L, L452R, I82T, P45L, V82A, F120L, F120L, and R203M), respectively. Phylogenetic analysis showed that the strains studied (KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021) belong to different SARS-CoV-2 lineages, which are closely related to samples from Germany (OU141323.1 and OU365922.1), Mexico (OK432605.1), and again Germany (OV375251.1 and OU375174.1), respectively. The nucleotide sequences of the studied SARS-CoV-2 virus strains were registered in the Genbank database with the accession numbers: ON692539.1, OP684305, and OQ561548.1.

Вирус гриппа птиц (AIV) подтипа H5 остаѐтся одним из наиболее значимых факторов эпизоотической и биологической безопасности. В рамках данного исследования проведѐн молекулярно-генетический и филогенетический анализ изолятов вируса, выделенных от водоплавающих птиц Северо-Казахстанской области в 2024 году. Полные последовательности гена гемагглютинина (HA 1704 н.п.) были определены методом Сэнгера и использованы для построения филогенетического древа с моделью Tamura – Nei. Обнаруженный полибазичный сайт расщепления NVPQRETR↓GLF указывает на низкопатогенный характер вирусов, характерный для циркуляции среди диких птиц. Филогенетический анализ показал принадлежность изолятов к клади 2.3.4.4b и формирование отдельного кластера с высокой поддержкой (bootstrap 98%), близкого к азиатским штаммам из Китая, Монголии и Кореи. Ключевые позиции рецептор-связывающего участка (Gln-226, Gly-228) сохраняют птичий α2,3- сиалогликановый профиль, что свидетельствует об отсутствии адаптации к млекопитающим. Выявленные аминокислотные замены в антигенных сайтах Sa, Ca2 и Cb не нарушают общую антигенную структуру. Полученные результаты указывают на формирование локальной эволюционной линии H5-вирусов, устойчиво циркулирующей среди водоплавающих птиц региона. Работа подчѐркивает роль Северо-Казахстанской области как ключевого звена в миграционных путях и эпидемиологической сети Евразии и обосновывает необходимость дальнейшего молекулярного мониторинга и геномного секвенирования для раннего выявления потенциально патогенных вариантов.

Prompt determination of the etiological agent is important in an outbreak of pathogens with pandemic potential particularly dangerous infectious diseases. Molecular genetic methods allow for arriving at an accurate diagnosis, employing timely preventive measures and controlling the spread of the disease causing agent. In this study, whole-genome sequencing of three SARS-CoV-2 strains was performed using the Sanger method, which provides high accuracy in determining nucleotide sequences and avoids errors associated with multiple DNA amplification. Complete nucleotide sequences of samples KAZ/Britain/2021, KAZ/B1.1/2021 and KAZ/Delta020/2021 were obtained with sizes of 29.751 bp, 29.815 bp and 29.840 bp, respectively. According to the COVID-19 Genome Annotator, 127 mutations were detected in the studied samples compared to the reference strain. The strain KAZ/Britain/2021 contained 3 deletions, 7 synonymous mutations and 27 non-synonymous mutations, the second strain KAZ/B1.1/2021 contained 1 deletion, 5 synonymous mutations and 31 non-synonymous mutations and the third strain KAZ/Delta020/2021 contained 1 deletion, 5 synonymous mutations and 37 non-synonymous mutations, respectively. Variations C241T, F106F, P314L and D614G found in the 5' UTR, ORF1ab and S region were common to all three studied samples, respectively. According to PROVEAN data, the loss-of-function mutations identified in strains KAZ/Britain/2021, KAZ/B1.1/2021 and KAZ/Delta020/2021 include 5 mutations (P218L, T716I, W149L, R52I and Y73C), 2 mutations (S813I and Q992H) and 8 mutations (P77L, L452R, I82T, P45L, V82A, F120L, F120L and R203M), respectively. Phylogenetic analysis showed that the strains studied (KAZ/Britain/2021, KAZ/B1.1/2021 and KAZ/Delta020/2021) belong to different SARS-CoV-2 lineages, which are closely related to samples from Germany (OU141323.1 and OU365922.1), Mexico (OK432605.1) and again, Germany (OV375251.1 and OU375174.1), respectively. The nucleotide sequences of the studied SARS-CoV-2 virus strains were registered in the Genbank database with the accession numbers: ON692539.1, OP684305, and OQ561548.1.