Coronavirus Infections in Animals: Risks of Direct and Reverse Zoonoses.

The publications on animal coronavirus infections that have the greatest emerging potential, as well as official data from the World Organization for Animal Health (OIE) on cases of animal infection with COVID-19, are analyzed. Like most infectious diseases common to humans, coronavirus infections were first discovered in animals. Due to the increased rate of replication and recombination activity compared to other viruses, mutations occur more often in the genome of coronaviruses, which contribute to the acquisition of new qualities in order to consolidate in the host organism. Examples of cross-species transmission are not only SARS-CoV, MERS-CoV, and SARS-CoV-2, which are dangerous to humans, but also coronaviruses of agricultural and domestic animals, between which there is a genetic relationship. There are several known cases of zoo, wild, domestic, and farm animals displaying symptoms characteristic of COVID-19 and identification of the genome of the SARS-CoV-2 virus in them. The issue of cross-species transmission of coronavirus infections, in particular the reverse zoonosis of SARS-CoV-2 from animals to humans, is widely discussed. According to the conclusions of many researchers, including OIE experts, there is no direct evidence base for infection of humans with COVID-19 from animals. However, people with suspected COVID-19 and with a confirmed diagnosis are still advised to isolate not only from people but also from animals. A number of methods for specific prevention, diagnosis, and immunization against a wide range of coronavirus infections are being developed at the All-Russia Research Institute for Animal Protection.

Genetic characteristics of spring viraemia of carp virus strains Kirov/08 and Orenburg/14.

The paper presents the genetic characteristics of two strains of spring viraemia of carp virus (SVCV), Kirov/08 and Orenburg/14, isolated in the Kirov and Orenburg oblasts of the Russian Federation, respectively. Nucleotide sequence analysis of a 516-bp fragment of the G genes of Kirov/08 and Orenburg/14 showed 9.5% divergence. Phylogenetic analysis demonstrated a close relationship of these strains to SVCV isolates recovered in Russia, Ukraine, and the Republic of Moldova.

Genetic analysis of genotype G57 H9N2 avian influenza virus isolate A/chicken/Tajikistan/2379/2018 recovered in Central Asia.

This paper presents genetic data on the full genome analysis of A/chicken/Tajikistan/2379/2018 H9N2 influenza virus isolated in September 2018 from chicken pathological material received from poultry farms of the Republic of Tajikistan and subtyped as H9N2 by serological and molecular methods. According to the results of hemagglutinin gene sequencing, the amino acid sequence of the cleavage site was RSSR/GLF, which is typical for low-virulent avian influenza virus. Phylogenetic analysis of the nucleotide sequence of a hemagglutinin gene fragment (nt 1-1539 of the open reading frame) showed that the A/chicken/Tajikistan/2379/2018 H9N2 isolate belongs to the Y280 genetic group of low-virulent A/H9 influenza virus, which is widespread in Southeast Asia. The complete nucleotide sequence of the viral genome was determined. Comparative analysis of all genomic segments revealed that the A/chicken/Tajikistan/2379/2018 H9N2 virus is closely related to an A/H9 influenza virus isolated in the Far East of the Russian Federation in 2018. Genetic similarity (97.1-99% identity in four out of eight viral genes) was found to isolates of an H7N9 subtype virus recovered in the Inner Mongolia and Hebei regions of China in 2017. According to the analysis of the predicted amino acid sequence of the studied isolate, the positions of some molecular markers indicate possible adaptation of the virus to mammals. Further genetic analysis showed that this virus belongs to genotype G57.

Genetic features of highly pathogenic avian influenza viruses A(H5N8), isolated from the European part of the Russian Federation.

Highly pathogenic avian influenza viruses (HPAIV) A(H5N8) of group B (Gochang1-like) have emerged in the Tyva Republic of eastern Russia in May 2016. Since November 2016, HPAIV A(H5N8) has spread throughout the European part of Russia. Thirty-one outbreaks were reported in domestic, wild and zoo birds in 2017. The present study aimed to perform a comparative analysis of new HPAIV A(H5N8) strains. Phylogenetic analysis revealed four genetically distinct subgroups in HPAIV A(H5N8) from the 2016-2017 season. Russian strains consisted of three subgroups with differences between isolates from Tyva, Siberia (Chany Lake), and the European part of Russia. Strains from the European part of Russia showed the beginnings of divergent evolution. Slight differences of the Voronezh strains were suggested by sensitivity to antiviral compounds. Testing for host-specific mutations in sequenced strains revealed the absence of mutations associated with possible increased tropism/virulence in mammalian species, including humans. Only one residue of polymerase basic-1, 13P, is discussed, because the L13P mutation increased complementary RNA synthesis in mammalian cells. We concluded that the evolution of HPAIV A(H5N8) is continuous. Surveillance in Russia revealed new cases of HPAIV A(H5N8) and led to the elaboration of prevention strategies, which should be implemented.

Immunization with live nonpathogenic H5N3 duck influenza virus protects chickens against highly pathogenic H5N1 virus.

Development of an effective, broadly-active and safe vaccine for protection of poultry from H5N1 highly pathogenic avian influenza viruses (HPAIVs) remains an important practical goal. In this study we used a low pathogenic wild aquatic bird virus isolate А/duck/Moscow/4182/2010 (H5N3) (dk/4182) as a live candidate vaccine. We compared this virus with four live 1:7 reassortant anti-H5N1 candidate vaccine viruses with modified hemagglutinin from either A/Vietnam/1203/04 (H5N1) or A/Kurgan/3/05 (H5N1) and the rest of the genes from either H2N2 cold-adapted master strain A/Leningrad/134/17/57 (rVN-Len and rKu-Len) or H6N2 virus A/gull/Moscow/3100/2006 (rVN-gull and rKu-gull). The viruses were tested in parallel for pathogenicity, immunogenicity and protective effectiveness in chickens using aerosol, intranasal and oral routes of immunization. All five viruses showed zero pathogenicity indexes in chickens. Viruses rVN-gull and rKu-gull were immunogenic and protective, but they were insufficiently attenuated and caused significant mortality of 1-day-old chickens. The viruses with cold-adapted backbones (rVN-Len and rKu-Len) were completely nonpathogenic, but they were significantly less immunogenic and provided lower protection against lethal challenge with HPAIV A/Chicken/Kurgan/3/05 (H5N1) as compared with three other vaccine candidates. Unlike other four viruses, dk/4182 was both safe and highly immunogenic in chickens of any age regardless of inoculation route. Single administration of 106 TCID50 of dk/4182 virus via drinking water provided complete protection of 30-days-old chickens from 100 LD50 of the challenge virus. Our results suggest that low pathogenic viruses of wild aquatic birds can be used as safe and effective live poultry vaccines against highly pathogenic avian viruses.

[Testing of apathogenic influenza virus H5N3 as a poultry live vaccine].

Four H5N2 experimental vaccine strains and the apathogenic wild duck H5N3 influenza virus A/duck/ Moscow/4182/2010 (dk/4182) were tested as a live poultry vaccine. Experimental strains had the hemagglutinin of the A/Vietnam/1203/04 strain lacking the polybasic HA cleavage site or the hemagglutinin from attenuated virus (Ku/ at) that was derived from the highly pathogenic influenza virus A/chicken/Kurgan/3/2005 (H5N1). The hemagglutinin of the Ku-at has the amino acid substitutions Asp54/Asn and Lys222/Thr in HA1 and Val48/Ile and Lys131/Thr in HA2, while maintaining the polybasic HA cleavage site at an invariable level. The other genes of these experimental strains were from the H2N2 cold-adapted master strain A/Leningrad/134/17/57 (VN-Len and Ku-Len) or from the apathogenic H6N2 virus A/gull/Moscow/3100/2006 (VN-Gull and Ku-Gull). A single immunization of mice with all tested strains elicited a high level of serum antibodies and provided complete protection against the challenge with the lethal dose of A/chicken/Kurgan/3/05. The pathogenicity indexes of the Ku-at and the other strains for chicken were virtually zero, whereas the index of the parent H5N1 virus A/chicken/Kurgan/3/2005 was 2.98. Intravenous, intranasal, and aerosol routes of vaccination were compared. It was shown that the strain dk/4182 was totally apathogenic for one-day-old chicken and provided complete protection against the highly pathogenic H5N1 virus.

Characteristics of pigeon paramyxovirus serotype-1 isolates (PPMV-1) from the Russian Federation from 2001 to 2009.

Monitoring programs for highly dangerous avian diseases in the Russian Federation from 2001 to 2009 detected 77 samples that were PCR positive for avian paramyxovirus serotype-1 (APMV-1) from sick or dead feral and domestic pigeons. Nucleotide sequences of the fusion (F) gene, including a nucleotide sequence encoding the F protein cleavage site, were determined for these isolates. All of the studied isolates possessed virulent F0 protein cleavage sites (112KRKKRF117, 112RRQKRF117, or 112KRQKRF117). Intracerebral pathogenicity index (ICPI) values determined for seven of the isolates exceeded the value of 0.7 (the range from 0.8 to 1.41). Based on partial genome sequencing and phylogenetic analysis, the isolates were assigned to two individual sublineages within class II genotype VIb. It was determined that most of these Newcastle disease virus isolates (70/77) recovered from the pigeons belonged to a relatively poorly studied sublineage VIb/2. The complete nucleotide sequence of the genome for the Pigeon/Russia/Vladimir/687/05 isolate of sublineage VIb/2 was determined.