Circulation of Antibiotic-Resistant Escherichia coli in Wild and Domestic Waterfowl in Ukraine.

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.

Discovery of Avian Paramyxoviruses APMV-1 and APMV-6 in Shorebirds and Waterfowl in Southern Ukraine.

Emerging RNA virus infections are a growing concern among domestic poultry industries due to the severe impact they can have on flock health and economic livelihoods. Avian paramyxoviruses (APMV; avulaviruses, AaV) are pathogenic, negative-sense RNA viruses that cause serious infections in the respiratory and central nervous systems. APMV was detected in multiple avian species during the 2017 wild bird migration season in Ukraine and studied using PCR, virus isolation, and sequencing. Of 4090 wild bird samples collected, mostly from southern Ukraine, eleven isolates were grown in ovo and identified for APMV serotype by hemagglutinin inhibition test as: APMV-1, APMV-4, APMV-6, and APMV-7. To build One Health's capacity to characterize APMV virulence and analyze the potential risks of spillover to immunologically naïve populations, we sequenced virus genomes in veterinary research labs in Ukraine using a nanopore (MinION) platform. RNA was extracted and amplified using a multiplex tiling primer approach to specifically capture full-length APMV-1 (n = 5) and APMV-6 (n = 2) genomes at high read depth. All APMV-1 and APMV-6 fusion (F) proteins possessed a monobasic cleavage site, suggesting these APMVs were likely low virulence, annually circulating strains. Utilization of this low-cost method will identify gaps in viral evolution and circulation in this understudied but important critical region for Eurasia.

Genetic diversity of Newcastle disease viruses circulating in wild and synanthropic birds in Ukraine between 2006 and 2015.

Newcastle disease virus (NDV) infects a wide range of bird species worldwide and is of importance to the poultry industry. Although certain virus genotypes are clearly associated with wild bird species, the role of those species in the movement of viruses and the migratory routes they follow is still unclear. In this study, we performed a phylogenetic analysis of nineteen NDV sequences that were identified among 21,924 samples collected from wild and synanthropic birds from different regions of Ukraine from 2006 to 2015 and compared them with isolates from other continents. In synanthropic birds, NDV strains of genotype II, VI, VII, and XXI of class II were detected. The fusion gene sequences of these strains were similar to strains detected in birds from different geographical regions of Europe and Asia. However, it is noteworthy to mention the isolation of vaccine viruses from synanthropic birds, suggesting the possibility of their role in viral transmission from vaccinated poultry to wild birds, which may lead to the further spreading of vaccine viruses into other regions during wild bird migration. Moreover, here we present the first publicly available complete NDV F gene from a crow (genus Corvus). Additionally, our phylogenetic results indicated a possible connection of Ukrainian NDV isolates with genotype XXI strains circulating in Kazakhstan. Among strains from wild birds, NDVs of genotype 1 of class I and genotype I of class II were detected. The phylogenetic analysis highlighted the possible exchange of these NDV strains between wild waterfowl from the Azov-Black Sea region of Ukraine and waterfowl from different continents, including Europe, Asia, and Africa.