Denys Muzyka

Wild waterfowl and shorebirds are the primary reservoir of influenza A viruses in nature. The role of wild birds from other taxonomic groups remains insufficiently studied or is a subject of debate. This applies in particular to Passeriformes, the most diverse avian order, accounting for approximately 60% of the global bird population, where the role in circulation of influenza A viruses is underexplored. We used serological, virological, and PCR-based methods to survey avian influenza viruses in Passeriformes birds (65 species, 20 families) in Ukraine over a 20-year period, 2004–2025. Antibodies to influenza viruses were detected in serum and egg yolk of seven passerine species, with average seroprevalence 1.24% in sera and 8.94% in yolk samples. Seroprevalence varied across species, ranging from 1.96 to 27.2%. Virological screening resulted in the isolation of two viruses from Fieldfares ( Turdus pilaris ) of the subtypes H1N1 and H7N1. The overall infection rate based on virus isolation was 0.15%, while local infection rate in Fieldfares reached 11.1%. According to PCR results, 41 positive samples were detected, representing 3.61% of all tested birds (ranging from 1.42–9.1%), and by location ranged from 6.25–9.1%. Sequencing and phylogenetic analyses of H1N1 (Fieldfare), H7N1 (Fieldfare), H3N8 (Great Tit Parus major ) influenza viruses confirmed them as Eurasian lineage low pathogenic avian influenza viruses and with close relatedness to viruses of the same subtypes circulating among wild waterfowl.

Avian influenza viruses are predominantly associated with waterfowl and shorebirds, and are rarely detected in other avian hosts in nature. In 2021, an H1N1 virus was isolated from a Fieldfare Turdus pilaris in Zaporizhzhia Oblast, Ukraine. A phylogenetic analysis revealed that all eight gene segments belonged to the Eurasian low-pathogenic avian influenza lineages. The highest nucleotide identity of the HA gene was observed with viruses detected in Georgia, Sweden, and Ukraine (99.11%), while the NA gene showed the greatest identity to viruses from Western Europe (99.14–99.57%). Genetic analysis of the HA cleavage site showed a sequence (PSIQSR↓GLF) that contained a single basic amino acid. No deletions were detected in the stalk region of NA gene, and no specific mutations in PB2 protein were found. However, several amino acid substitutions were identified in the HA gene (D204E, S207T, and D239G) that may affect the binding affinity to specific antibodies. The occurrence of this virus in a wild, seemingly healthy thrush indicate that additional surveillance in poorly studied ecological groups such as Passeriformes is warranted.

Myotis alcathoe is one of the iconic species among cryptic European bats, described only 20 years ago. Despite research efforts, there is still limited knowledge about its distribution and ecology, leading to its Data Deficient status on the IUCN Red List. Ukraine lies on the eastern border of the species' range, with only a few known records. Here, we document a new genetically confirmed record of M. alcathoe from the Central-Western part of Ukraine (Rivne Region, in “Dermansko-Ostrozkyi” National Nature Park). Eight individuals were mist-netted in late April 2023 near a mine entrance, alongside a few Myotis nattereri and Myotis bechsteinii. This record extends the known range of M. alcathoe 30–40 km to the northeast, marking the second genetically confirmed record of this species in Ukraine. The woodlands of the National Park area, characterized by wet old-growth oak and hornbeam forests, seem to be suitable summer habitats for this species. Continued bat surveys during the breeding season are necessary in the area to better understand its habitat preferences and distribution.

The publication combines the results of ornithological observations of the greater white-fronted goose, Anser albifrons (Scopoli, 1769) during migration and wintering in the south-western part of Odesa Region of Ukraine (Bilhorod-Dnistrovskyi, Izmail, and Bolhrad districts) and the results of laboratory tests of biological samples of this species for the presence of the influenza A pathogen. The study was conducted in 2017–2019. A total of 1,591 samples of biological material (feces) of the greater white-fronted goose, collected in 48 locations in Odesa Region, were examined using polymerase chain reaction (PCR). The influenza A virus genome was detected in 23 samples. The total annual prevalence was 1.44%, in winter — 1.44%, in spring — 1.81%. During the fall migration, no influenza A virus was detected in the genome samples, which determines the wintering period as the most important stage of integration of the greater white-fronted goose in maintaining the natural circulation of influenza A in the study area. By year, the prevalence was distributed as follows: in 2017 — 1.75%, in 2018 — 1.97%, in 2019 — 0.78%. All cases of detection of influenza A virus genome in fecal samples of the greater white-fronted geese concerned areas near large bodies of water in the coastal part of the Black Sea (Sasyk Lagoon and Tuzly Lagoons). Among the factors that may determine the high involvement of the greater white-fronted goose in the circulation of influenza A in these areas are the presence of other sources of infection: numerous dense multi-species aggregations of birds in the wetland complex and favorable conditions for pathogen transfer

West Nile fever is a very dangerous zoonotic viral disease of animals and humans. It is a naturally occurring focal disease, the natural cycle of which involves a natural reservoir of pathogens, such as wild birds, and vectors, such as mosquitoes, ticks, etc. Today, the problem of West Nile fever is becoming increasingly relevant from an epidemiological point of view. Natural foci of this disease pathogen have been present in Ukraine for a long time in the southern and eastern regions, but now, due to climate change, there are changes in the ecology of both natural carriers and vectors, which significantly changes the epidemiological risks to humans. Over the past few years, in particular, in 2024, an increase in human cases, including fatalities, has been recorded in Ukraine. At the same time, there is a lack of up-to-date information on the circulation of West Nile virus and other flaviviruses (Usutu virus, etc.) in the natural reservoir and among vectors in Ukraine. Our research aimed to conduct serological monitoring in Ukraine among wild forest birds, which are one of the main natural reservoirs of the West Nile virus. During 2023-2024, 268 blood samples and 9 egg yolks of wild Passeriformes (families buntings, finches, true sparrows, tits, bushtits, shrikes, wagtails, Hirundinidae) and Piciformes were collected in Kharkiv, Kyiv, Poltava, Odesa, and Khmelnytsky regions. Blood serum and egg yolks were tested in the ELISA ID.Vet - ID Screen West Nile. It was found that antibodies to WN virus were present in blood samples from Great Tits (seroprevalence from 20% to 100% depending on the region), Song Thrush (60–100%), Blackbird (93%-100%), Chaffinch (100%), Goldfinch (100%), House Sparrow (100%), Greenfinch (10% and 100%), hawfinch (100%), Jays (50%), Field Sparrow (20% and 25%), and Great Reed warbler (40%), reed warbler (33.3%), Сommon whitethroat (25%), Robin (100%), Yellowhammer (100%), Blackcap (100%), Spotted flycatcher (100%), Pied flycatcher (100%), Thrush nightingale(100%). No antibodies to the WN virus were detected in the barn Swallow, Sedge Warbler, Paddyfield Warbler, Collared Flycatcher, Reed Bunting, Spanish Sparrow, Common Woodpecker, Goldfinch, Red-backed Shrike. Seropositivity was found in wild birds from all regions studied. The highest percentage of seropositive birds was found in Poltava (86%, 58%) and Khmelnytsky (67%) regions, and the lowest in Kyiv (9%) and Odesa (17.1%) regions. We also found a difference in seropositivity in different years. Thus, in 2023 it was 27.4%, and in 2024 it was 50.5%

The article provides a brief historical background of equine influenza, the spread of this disease worldwide, and the current epizootic situation. The results of serological monitoring by ELISA of wild and domestic ungulates from different farms and regions of Ukraine for the presence of antibodies to influenza A viruses are presented. Blood serum samples from 372 domestic horses and 32 wild ungulates were tested. Samples from animals collected in 2023 and 2024 and archival blood serum samples from 2021 were used and tested according to the manufacturer’s instructions using ELISA test systems manufactured by IDEXX, INGEZIM, and IDVet. The data obtained indicate a fairly active circulation of influenza A viruses in populations of unvaccinated domestic horses. The circulation was established not only in recent years (2023–2024, seroprevalence from 10% to 100%), but was observed earlier, as evidenced by the detection of 60.9% of positive samples in samples collected in 2021. In addition, two out of three positive samples were found in wild horses from Kherson Region, which indicates the circulation of influenza A virus among wild animals and requires further investigation. The results correlate with the worsening of the epidemiological situation regarding influenza in animals in Europe. The subsequent phase of the research is serotyping, which involves determining the presence of antibodies to specific virus subtypes by hemagglutinin

Feather mites (Acariformes, Astigmata) are a large group of species in which mites of the genus Proctophyllodes Robin, 1868. Analgoidea are among the most common parasites of passerines. These mites are permanent obligate ectoparasites localized on the flight feathers, greater wing coverts, and on the tail. Most species of feather mites are characterized by high host specificity. The taxonomy and fauna of feather mites of the genus Proctophyllodes, and their morphological identification characters in different countries of the world are still a matter of research. The aim of our work was to describe the morphological features and metric parameters of feather mites of the species P. musicus Vitzthum, 1922, isolated from the common blackbird Turdus merula Linnaeus, 1758 in Ukraine. 32 parameters are determined in males and females of P. musicus mites, which characterize both their general structure of the body and sexual dimorphism. The structure and sizes of the body, gnathosoma, idiosoma, prodorsal and hysteronotal shields, epimerites I, setae cp and c3, and the distance between setae of the scapula se–se and si–si are described. In males, the sizes of adanal sucker discs, epigastric shields, genital arch, setae ps2, h3, h2, the distance between setae 4a–4a, g–g, ps3–ps3, ps1–ps1 are additionally described and determined. Lamellae in males are wide, tongue-shaped, do not overlap. The aedeagus is short, slightly extending beyond the posterior margin of the genital arch. In female mites, the dimensions of the lobar shield, terminal appendages, and terminal recess are additionally described and determined, taking into account the location of setae ps1, h2, the dimensions of setae cp, c3, h3, h2, the distance between setae h1–h1, the distance between hysteronotal and lobar shields. The mite eggs were measured in the body of the female and on the feathers of the birds. The scientific data obtained in this study expand the already existing data on morphological and metric characters of feather mites of the species P. musicus (Proctophyllodidae) isolated from the common blackbird.

Background: Antibiotic resistance is becoming an increasingly urgent problem for human and animal health due to the widespread use of antibiotics in medicine, veterinary medicine, and agriculture. At the same time, the natural reservoirs of antibiotic-resistant pathogens remain unclear. Wild birds may play a role in this due to their biology. Escherichia coli is a representative indicator pathogen for antibiotic resistance studies. Materials and Methods: In 2020–2021, sampling of feces and cloacal swabs from six species of wild waterfowl (Eurasian wigeon Anas penelope, Eurasian teal Anas crecca, white-fronted goose Anser albifrons, red-breasted goose Rufibrenta ruficollis, graylag goose Anser anser, shelduck Tadorna tadorna) and from two species of domestic waterfowl (ducks and geese) was conducted in the Kherson, Zaporizhzhia, Odesa, Kharkiv, and Cherkasy regions of Ukraine. Biological material was collected, stored, and transported in cryotubes with transport medium (brain heart infusion broth [BHIB] with the addition of 15% glycerol) in liquid nitrogen. Bacteriological studies were carried out according to standard methods for the isolation and identification of microorganisms. Drug resistance of E. coli was carried out by a standard disk diffusion method. Results: Bacteria representing six families (Enterobacteriaceae, Yersiniaceae, Morganellaceae, Bacillaceae, Pseudomonadaceae, Staphylococcaceae) were isolated from clinically healthy wild birds (wigeon, Eurasian teal, white-fronted goose, red-breasted goose, mallard, graylag goose, shelduck) in the southern regions of Ukraine with isolation rates ranging from 26.7% to 100%. A total of 19 E. coli isolates were cultured from 111 samples from wild birds, and 30 isolates of E. coli were cultured from 32 poultry samples. E. coli was isolated from birds of all species. The prevalence of E. coli ranged from 5.0% to 33.3% in wild waterfowl and from 90.9% to 100% in domestic waterfowl. The prevalence of multidrug-resistant (MDR) E. coli ranged from 10.0% to 31.8% in wild and domestic waterfowl: 3 of 15 (20%) specimens from wild mallard were MDR in the Kherson region, as well as 7 of 22 domestic ducks (31.8%) and 1 of 10 geese (10%) in the Kharkiv and Cherkasy regions. Isolates from wild birds were the most resistant to ampicillin (AMP), amoxiclav (AMC), amoxicillin (AMX), doxycycline (DO), and chloramphenicol (C). Isolates from poultry were resistant to ampicillin, amoxiclav, doxycycline, amoxicillin, chloramphenicol, and enrofloxacin (EX). Most of the other E. coli isolates from wild waterfowl were classified as non-multidrug-resistant (non-MDR) forms. Analysis of antibiotic sensitivity phenotypes showed that only four antibiotic-resistant phenotypes were detected among non-MDR bacteria, whereas among the MDR bacteria, two antibiotic-resistant phenotypes were detected in mallards and six in domestic waterfowl. Conclusion: The results of this study showed that wild waterfowl in Ukraine, which live in natural conditions and do not receive any antimicrobial drugs, are carriers of E. coli that are resistant to a number of antibiotics that are actively used in industrial poultry.

Veterinary Medicine, Inter-departmental Subject Scientific Collection, NSC

The article provides a brief review of the literature on influenza viruses, including their prevalence, classification, pathogenicity, ability to mutate and reassort, and some peculiarities of their biological properties. Special attention is given to swine influenza, since interspecies transmission of influenza viruses between pigs and humans can have serious consequences for both human and veterinary medicine. The results of pilot studies conducted at the NSC ‘IECVM’ prove the circulation of influenza A viruses among pigs in Ukraine — 324 samples of blood sera from pigs of different age groups from different regions of Ukraine were tested using an ELISA test system, 48 (14.8%) positive samples were found. Seroprevalence reached 100% in some farms and antibodies were detected in animals aged 24–73 days. The prospect of further work is to conduct surveillance studies (serological, molecular biological, virological) of pigs in both large breeding complexes and private households to detect antibodies to influenza A and, based on the results obtained, to draw conclusions about the circulation of influenza A viruses in Ukraine