This study introduces a new approach to monitoring avian diversity and vocal behavior, as well as assessing their responses to environmental factors using IoT-based sensors. We utilized BirdNet, a deep learning model for identifying bird species by their vocalizations, to data from our MINTS-AI environmental sensors deployed across Dallas, Texas. The study investigates how ambient temperature, humidity, light intensity, and particulate matter concentrations affect bird behavior. The results show a positive correlation between bird diversity and temperature during winter, with a Pearson coefficients of 0.65 (2023) and 0.80 (2024), and R2 values of 0.43 and 0.64, respectively. In contrast, during summer, a negative correlation was found with Pearson coefficients of -0.63 (2023) and -0.34 (2024), with corresponding R2 values of 0.40 and 0.11. Machine learning models further highlighted species such as the Northern Mockingbird and Mississippi Kite as particularly sensitive to temperature changes. Humidity analysis revealed significant correlations of vocal activity for species like the Canada Goose and House Finch, indicating that vocal activity may depend on moisture levels. Light intensity also showed strong influences on species such as the Northern Mockingbird and Scissor-tailed Flycatcher, linking variations in light to vocal behavior. However, no significant relationship was found between particulate matter (PM2.5) concentrations and bird behavior. This methodology offers a new way to explore the effects of climate change on bird behavior over time, given adequate long-term data. These findings emphasize the important role of environmental changes in shaping bird populations and their ecological interactions.

High pathogenicity avian influenza (HPAI) H5N1 clade 2.3.4.4b continues to have a substantial impact on wildlife, globally. A recent study has described the putative detection of HPAI in clinically healthy penguins, and those which were fitted with satellite tags reportedly engaged in apparently normal foraging behaviour in the months following sample collection. Herein we investigate the diagnostic approach utilised, and reveal that while the authors likely did detect subtype H5 influenza A virus, the most parsimonious conclusion is that they detected low pathogenicity H5 rather than HPAI H5N1. In response, we have provided an overview key considerations when selecting a diagnostic and outline published diagnostic assays that should be considered for future studies.

In 2021/2022, the re-emergence of highly pathogenic avian influenza (HPAI) occurred in Europe. The outbreak was seeded from two sources, resident and reintroduced viruses, which is unprecedented in the recorded history of avian influenza. The dominating subtype was H5N1, representing a reversion to the original A/goose/Guangdong/1/1996-like subtype combination. In this study, we present a whole genome sequence and a phylogenetic analysis of 57 H5N1 HPAI and two low pathogenic avian influenza (LPAI) H5N1 strains collected in the Czech Republic during 2021/2022. Phylogenetic analysis revealed close relationships between H5N1 genomes from poultry and wild birds and secondary transmission in commercial geese. The genotyping showed considerable genetic heterogeneity among Czech H5N1 viruses with six different HPAI genotypes, three of which were apparently unique. In addition, second-order reassortment relationships were observed with the direct involvement of co-circulating H5N1 LPAI strains. The genetic distance between Czech H5N1 HPAI and the closest LPAI segments available in the database illustrates the profound gaps in our knowledge of circulating LPAI strains. The changing dynamics of HPAI in the wild may increase the likelihood of future HPAI outbreaks and present new challenges in poultry management, biosecurity, and surveillance.

In 2020-2021, the second massive dissemination of a highly-pathogenic avian influenza (HPAI) of H5Nx subtype occurred in Europe. During this period, the virus caused numerous outbreaks in poultry, including in the Czech Republic. In the present study, we provide an insight into the genetic variability of the Czech/2021 (CZE/2021) H5N8 viruses to determine the relationships between strains from wild and domestic poultry and to infer transmission routes between the affected flocks of commercial poultry. For this purpose, whole genome sequencing and phylogenetic analysis of 70 H5N8 HPAI genomes representing 79.7% of the cases were performed. All CZE/2021 H5N8 viruses belonged to the 2.3.4.4b H5 lineage and circulated without reassortment, retaining the A/chicken/Iraq/1/2020 H5N8-like genotype constellation. Phylogenetic analysis suggested frequent local transmission of H5N8 HPAI from wild birds to minor poultry and extensive farm-to-farm spread among commercial poultry farms. In addition, the analysis suggested one cross-border transmission event. Indirect transmission via contaminated materials was considered the most likely source of infection. Improved biosecurity and increased collaboration between the field veterinarians and the laboratory are essential to limit the local spread of the virus and to reveal and interrupt critical routes of infection.

Influenza A viruses (IAVs) evolve via point mutations and reassortment of viral gene segments. The patterns of reassortment in different host species differ considerably. We investigated the genetic diversity of IAVs in wild ducks and compared it with the viral diversity in gulls. The complete genomes of 38 IAVs of H1N1, H1N2, H3N1, H3N2, H3N6, H3N8, H4N6, H5N3, H6N2, H11N6 and H11N9 subtypes isolated from wild mallard duck and gull habitants of a pond in Moscow city, Russia were sequenced. The sequences were closely related to those of avian IAVs isolated in Sweden and the Netherlands. The analysis of phylogenetic trees showed that stable viral genotypes do not persist from year to year in ducks owing to frequent gene reassortment. For comparison, similar analyses were carried out using sequences of IAVs isolated in the same period from ducks and gulls in the Netherlands. Our results revealed a significant difference in diversity and rates of reassorment of IAVs in ducks and gulls.

We utilized camera traps to assess animal diversity, relative abundance, and anthropogenic activities in the Jhalana Reserve Forest (JRF), located amidst Jaipur, with a population of 3.9 million people. Between November 2017 and November 2019, camera traps were strategically deployed in both the tourist zone and peripheral areas, capturing 16,328 photos. This study represents the first comprehensive baseline assessment of animal diversity in JRF, documenting a total of 39 species, including 18 bird species, 14 mammals, and six domestic species, alongside human activity. Among the 14 mammal species, seven were carnivores. Notably, we identified 25 individual Indian leopards (Panthera pardus fusca) during 2017-2018, comprising 8 males and 17 females, highlighting the leopard as the apex predator in JRF. Concurrently, domestic animals accompanied by humans were observed within JRF. However, rigorous conservation efforts and patrols by the Rajasthan Forest Department resulted in a notable decline in human intrusion, reducing from 28.0% in 2017-18 to 3.9% in 2018-2019, with domestic animal activity reaching zero in the latter period. Consequently, the relative abundance of wildlife species increased during the study period of 2018-2019, underscoring the positive impact of conservation strategies implemented by authorities. Our findings affirm that camera traps effectively establish baseline data, assess animal diversity, and evaluate relative abundance in reserve forests situated within human-dominated landscapes. This study provides critical insights to inform the development and implementation of conservation strategies in similar protected areas.

Avian metapneumovirus subgroup C (aMPV/C) causes respiratory diseases and egg dropping in chickens and turkeys, resulting in severe economic losses to the poultry industry worldwide. Integrin β1 (ITGB1), a transmembrane cell adhesion molecule, is present in various cells and mediates numerous viral infections. Herein, we demonstrate that ITGB1 is essential for aMPV/C infection in cultured DF-1 cells, as evidenced by the inhibition of viral binding by EDTA blockade, Arg-Ser-Asp (RSD) peptide, monoclonal antibody against ITGB1, and ITGB1 short interfering (si) RNA knockdown in cultured DF-1 cells. Simulation of the binding process between the aMPV/C fusion (F) protein and avian-derived ITGB1 using molecular dynamics showed that ITGB1 may be a host-factor for benefiting aMPV/C attachment or internalization. Transient expression of avian ITGB1 rendered porcine and feline non-permissive cells (DQ cells and CRFK cells, respectively) susceptible to aMPV/C infection. Replication kinetic of aMPV/C in siRNA-knockdown cells revealed that ITGB1 plays an important role in aMPV/C infection at the early stage (attachment and internalization). aMPV/C was also able to infect efficiently human non-small cell lung cancer (A549) cells. This may be due to a consequence of the similar structures of both metapneumovirus F protein-specific motifs (RSD for aMPV/C and RGD for human metapneumovirus) recognized by ITGB1. Overexpression of avian-derived ITGB1 and human-derived ITGB1 in A549 cells enhanced aMPV/C infectivity. Taken together, this study demonstrated that ITGB1 acts as an essential receptor for aMPV/C attachment and internalization into host cells in which facilitates aMPV/C infection.

Competent authorities of many countries, including Belgium, impose control measures (preventing wild bird access to feeders and water facilities, indoor confinement of captive birds, or fencing off outdoor ranges with nets) to professional and non-professional keepers of birds to prevent the spread of avian influenza (AI). Flemish laying hen farmers (FAR, n = 33) and private keepers of captive birds (PRI, n = 263) were surveyed about their opinion on, and compliance with, AI-measures legally imposed during the most recent high-risk period before this survey in 2021. Participants answered questions on a 5-point Likert scale (1 = the worst, 3 = neutral, and 5 = the best). FAR indicated better compliance with the AI-measures compared to PRI, except for confinement with nets. PRI and FAR perceived the level of compliance with AI-measures by other private bird keepers to be lower compared to themselves. FAR regarded the AI-measures as more effective than PRI. To prevent the spread of AI more effectively, national authorities could focus on information campaigns explaining to private bird keepers, in particular, the need for the various control measures that they impose, implement alternative control measures that have broader support or implement stricter enforcement of the control measures.

Nanoparticle-assisted polymerase chain reaction (nanoPCR) is a novel method for rapid detection of pathogens. A sensitive and specific multiple nanoPCR assay was developed for simultaneous detection of three subgroups avian leucosis virus (ALV). In this study, three pairs of primers that were designed based on gp85 gene sequences of subgroup A, B and J, optimizations were carried out for better performance of the nanoPCR assay and remarkably improved the detection limit of the assay. The detection limit of the assay was 101copies/μl, which was 100-fold more sensitive than conventional PCR assays. The nanoPCR assay amplified the specific 336 bp, 625 bp and 167 bp fragments of ALV-A, -B and –J respectively and no cross-reactivity were found with the genomic DNA or cDNA of Newcastle disease virus, avian infectious laryngotracheitis virus, Marek's disease virus, infectious bronchitis vaccine, infectious bursal disease virus and avian encephalomyelitis Virus. To evaluate the detection ability of the assay, 186 clinical samples were detected by nanoPCR and the detection results were further confirmed by sequencing. The sequencing results were 100% in coincidence with the nanoPCR detection results, suggesting the possibility of clinical application of the newly developed nanoPCR assay. Taking all the results together, a highly specific and sensitive nanoPCR was successfully developed, which could be useful for rapid diagnosis of ALV in poultry farming.

The H7 subtype of avian influenza viruses (AIV) stands out among other AIV. The H7 viruses cir-culate in ducks, poultry, equine and have repeatedly caused outbreaks of disease in humans. In or-der to study the pathogenicity factors of H7N1 viruses, several variants were obtained, starting with laboratory strain, with a history of 12 passages through chicken embryos. This strain, A/chicken/Rostock/R0p/1934(H7N1) (R0p) had only 3 substitution in HA relatively A/Chicken/Rostock/45/34(H7N1), substitution Arg140Gly among them. 10 variants of this strain was obtained and studied to ascertain its biological property, genome stability and factors of patho-genicity. Strain R0p had decreased virulence for chicken, comparing with described in literature virulence of A/FPV Rostock/34 and A/chicken/Rostock/34 viruses. After 10 passages through the chicken lungs variant was obtained much more pathogenic than the starting R0p. The study of in-termediate passages through the chicken lungs showed that the jump in pathogenicity had occurred sharply between the fifth and sixth passage. By cloning these variants, a pair of strains (R5p and R6p) were obtained, and the complete genomes of these strains were sequenced. Single amino acid substitution was revealed, namely reversion Gly140Arg in HA1. This amino acid is located at the head part of the hemagglutinin, adjacent to the receptor-binding site. In addition to the increased pathogenicity for chicken and mice, R6p differs from R5p in the pattern of foci in cell culture and an increased affinity for a negatively charged receptor analogue, while maintaining a pattern of recep-tor binding specificity and the pH optimum of the HA conformational change.

The H7 subtype of avian influenza viruses (AIV) stands out among other AIV. H7 viruses circulate in ducks, poultry, equine and have repeatedly caused outbreaks of disease in humans. In order to study the pathogenicity factors of H7N1 viruses, several laboratory variants of the A/FPV/Rostock/34 (H7N1) strain were obtained by passages in the chicken lungs. After 10 such passages, a variant was obtained that differed from the parent virus by amino acid substitutions Val109Phe in PB2, Gln621Lys in PB1, Thr32Ala and Leu586Phe in PA Gly140Arg in HA1 and Ala101Thr in HA2 (numbering by H3), Ser82Arg in M2, Arg118Lys and Met124Arg in NS1. No differences were found in proteins NA, NP, M1 and NS2. The resulting variant was hundreds of times more pathogenic for chickens than the original laboratory variant of the virus. The study of intermediate passages showed that the jump in pathogenicity occurs sharply between the fifth and sixth passage through the chicken lungs. By cloning these variants, a pair of strains (R5p and R6p) were obtained, and the complete genomes of these strains were sequenced. Single amino acid substitution was revealed, namely Gly140Arg in HA1. It is important to emphasize that this substitution is a reversion, since Arg is located in position 140 HA1 of original the A/FPV/Rostock/34 (H7N1) virus (GenBank). This amino acid is located at the head part of the hemagglutinin, adjacent to the receptor-binding site. In addition to the increased pathogenicity, R6p differs from R5p by an increased affinity for a negatively charged receptor analogue, an increased affinity for MDCK cells, while maintaining a receptor specificity profile.

As exemplified by the global response to the SARS-CoV-2 pandemic, whole genome sequencing played an important role in monitoring the evolution of novel viral variants and provided guidance on potential antiviral treatments. The recent rapid and extensive introduction and spread of highly pathogenic avian influenza virus in Europe, North America and elsewhere raises the need for similarly rapid sequencing to aid in appropriate response and mitigation activities. To facilitate this objective, we investigated a next generation sequencing platform that uses a portable nanopore sequencing device to generate and present data in real time. This platform offers the potential to extend in-house sequencing capacities to laboratories that may otherwise lack resources to adopt sequencing technologies requiring large benchtop instruments. We evaluated this platform for routine use in a diagnostic laboratory. In this study we evaluated different primer sets for the whole genome amplification of influenza A virus and evaluated five different library preparation approaches for sequencing on the nanopore platform using the MinION flow-cell. A limited amplification procedure and a rapid procedure were found to be best among the approaches taken.

Following the detection of highly pathogenic avian influenza (HPAI) virus in countries bordering Kenya to the west, we conducted surveillance among domestic and wild birds along the shores of Lake Victoria. In addition, between 2018 and 2020, we conducted surveillance among poultry and poultry workers in live bird markets and among wild migratory birds in various lakes that are resting sites during migration to assess introduction and circulation of avian influenza viruses in these populations. We tested 7,464 specimens (oropharyngeal and cloacal swabs) from poultry and 6,531 fresh fecal specimens from wild birds for influenza A viruses by real-time RT-PCR. Influenza was detected in 3.9% (n=292) of specimens collected from poultry and 0.2% (n=10) of fecal specimens from wild birds. On hemagglutinin subtyping, most of the influenza A positives from poultry (274/292, 93.8%) were H9. Of 34 H9 specimens randomly selected for further subtyping, all were H9N2. On phylogenetic analysis, these viruses were genetically similar to other H9 viruses detected in East Africa. Only two of the ten influenza A positive specimens from the wild bird fecal specimens were successfully subtyped; sequencing analysis of one specimen collected in 2018 was identified as low pathogenicity avian influenza H5N2 virus of the Eurasian lineage and the second specimen, collected in 2020, was subtyped as H11. A total of 18 OP/NS swabs from poultry workers with ARI (12%) were collected; none were positive for influenza A virus. We observed significant circulation of H9N2 influenza viruses in poultry in live bird markets in Kenya. During the same period, low pathogenic H5N2 virus was detected in a fecal specimen collected in a site hosting a variety of migratory and resident birds. Although HPAI H5N8 was not detected in this survey, these results highlight the potential for introduction and establishment of highly pathogenic avian influenza viruses in poultry populations and the associated risk of spillover to human populations.

المستخلص تصنيع لقاح مكون من الحمض النووي الريبوزي الرسول الخاص بالبروتينات المسئولة عن انتاج البروتينات نيورامنيديز والهيم اجليوتونين لفيروسي الانفلونزا الخنازير والطيورمحاط بجزيئات دهنية بحجم النانوميتر عدوى انفلونزا الخنازير وانفلونزا الطيور مشكلة خطيرة تؤرق العالم كله هذه الايام خصوصا انها مميتة لكثير من اطفال العالم . بعد فترة التعافي من الاصابة تتكون المناعة المكتسبة ضدها لمدة عام تقريبا. هذه الانفلونزا تسبب تسمم فيروسي في الدم بالاضافة للالتهاب الرئوي وهذامن بين اكبرالاسباب للوفاة بين الاطفال قبل سن عامين عالميا بشكل مباشر. الهدف من الدراسة هو انتاج لقاح الحمض النووي الريبوزي الرسول من نوع الام بالنانوتكنولوجي لبروتينات الهيم اجليوتونين والنيورامنيديز الموجودة على سطح هذه الفيروسات التي تساعدتها في الاتصاق بالعائل الذي ستتكاثر داخل خلاياه بالجهاز التنفسي. هذه الدراسة دراسة استكشافية ومن خلالها استطاعنا تصميم هذا اللقاح باستعمال نظام توصيل للقاح بالنانوتكنولوجي حجم جزيئاته 70نانوميمتر. اللقاح الجديد اظهر فاعلية بنسبة 60% واظهر فاعلية حيوية مقاربة واثار جانبية اقل بالمقارنة باللقاحات المتوفرة حاليا بالسوق الدوائي ضد هذا النوع من الفيروسات الوبائية. ABSTRACT Background: Worldwide, Swine and Avian influenza, or the H1N1 and H5N1 serotypes of the Influenza A virus, is a highly contagious illness. In recent years, the global incidence of mortality rate has surpassed 284,000 fatalities. Aim of the study: The production of mRNA vaccine lipid nanoparticles (LNP) to combat the deadly strains of Avian and Swine influenza (H1N1 and H5N1 of the influenza A serotype). Methodology: Polymerase chain reaction (PCR) was used to clone genes of interest encoding Haemagglutinin (HA) and Neuraminidase (NA) of Influenza A virus strains (H5N1 and H1N1) known as Avian flu and Swine flu, respectively. The genes were then inserted using the EcoR1, BAM Hind II restriction endonuclease type II, and Ligase enzyme into the pET-21(+) transcription vector plasmid. On the other hand, the hybrid transcription vectors were mixed with T7 RNA polymerase and ribonucleotides within a test tube after being linearized using EcoR II. Following their purification via reversed-phase high-performance liquid chromatography (RP-HPLC), the mRNAs of the HA and NA were encased in 70 nm LNPs and subjected to reverse-phase high-performance liquid chromatography (RP-HPLC). Lastly, immunogenicity studies were performed in stages 1/2 of randomized human and preclinical clinical trials. Results: The bivalent vaccination had around 63% efficacy in preclinical studies and approximately 60% efficacy in randomized human clinical trials. As shown by the ELISA test, strong neutralizing antibodies against HA were prevalent. Conclusion: The current study is a promising effort because of the development of the novel LNP-mRNA vaccine, which could lower the incidence of Avian and Swine flu infectious disorders.

There are four types of influenza viruses: A, B, C, and D. Cattle are susceptible to influenza D infection and serve as a reservoir for this seven-segmented influenza virus. It is generally thought that bovines are not a host of other types of influenza viruses including type A. This long-standing viewpoint has been challenged by the recent highly pathogenic avian influenza (HPAI) H5N1 outbreaks in dairy cows in the United States. To date, HPAI H5N1 has spread into nine states affecting 49 dairy herds and causing clinical symptoms including reduced appetite, fever, and a sudden drop in milk production. This review article describes the current epidemiological landscape of HPAI H5N1 in U.S. dairy cows and the recent interspecies transmission events of HPAI H5N1 in other mammals reported in other countries. The review also discusses adaptation mutations of HPAI H5N1 to mammalian hosts and vaccination strategies. Finally, it summarizes some immediate questions that need to be addressed towards a better understanding of infection biology, transmission, and immune response of HPAI H5N1 in bovines.

Haemosporidians are a group of vector-borne parasites belonging to the order Haemosporida. They infect avian hosts and require blood-sucking insects (Diptera) for their transmission. The occurrence and diversity of haemosporidian parasites are shaped primarily by the specificity of the parasite and the susceptibility of the host/vector. In this study, the presence and distribution of haemosporidians in blood samples from birds in urbanized and natural habitats were estimated using microscopic and molecular approaches. Birds in urbanized habitats were infected with four different species of Plasmodium: Plasmodium relictum, P. vaughani, P. matutinum, P. circumflexum, two different species of Haemoproteus: Haemoproteus majoris, H. parabelopolskyi, and Leucocytozoon sp. The species, H. attenuatus, H. concavocentralis, H. minutus, H. pallidus, H. noctue and H. tartakovskyi were additionally identified in birds in natural habitats. Typically, juvenile birds are essential markers of parasite species transmitted in the study area. The juveniles in the urbanized habitats carried the P. relictum, P. vaughani, P. circumflexum, H. parabelopolskyi, H. majoris, and Leucocytozoon species. The most abundant parasite was H. parabelopolskyi, which was found in both types of habitats. The prevalence of the Haemoproteus/Plasmodium species by nested PCR in birds in natural habitats (in totally 43.80%; 53/121) was significantly higher than that in birds in urbanized habitats (in totally 21.94%; 43/196) (p < 0.05), even in spring. There was no statistically significant difference between habitat types in overall infection rate of Leucocytozoon sp. (p > 0.05; 10/121 vs. 19/196), neither overall nor in the spring.

We isolated two highly pathogenic avian influenza viruses (HPAIVs) of subtype H5N8 clade 2.3.4.4b from falcated duck (Anas falcata) feces and environmental water collected at an overwintering site in Japan. Our isolates were almost genetically identical to each other and showed high genetic similarity with H5N8 HPAIVs recently isolated in South Korea, a distant part of Japan, and European countries. These results suggest the potential role of falcated ducks in the dissemination of HPAIVs.

H9N2 avian influenza viruses have become globally widespread in poultry over the last two decades and represent a genuine threat both to the global poultry industry but also humans through their high rates of zoonotic infection and pandemic potential. H9N2 viruses are generally hyperendemic in effected countries and have been found in poultry in many new regions in recent years. In this review we examine the current global spread of H9N2 avian influenza viruses as well as their host range, tropism, transmission routes and the risk posed by these viruses to human health.

The GLUT members belong to a family of glucose transporter proteins that facilitate glucose transport across the cell membrane. The mammalian GLUT family consists of thirteen members (GLUTs 1-12 and HMIT). Humans have a recently duplicated GLUT member, GLUT14. Avians express the majority of GLUT members. The arrangement of multiple GLUTs across all somatic tissues signifies the important role of glucose across all organisms. Defects in glucose transport have been linked to metabolic disorders, insulin resistance and diabetes. Despite the essential importance of these transporters, our knowledge regarding GLUT members in avians is fragmented. It has been clear that there are no chicken orthologs of mammalian GLUT4 and GLUT7. Our examination of GLUT members in the chicken revealed that some chicken GLUT members do not have corresponding orthologs in mammals. We review the information regarding GLUT orthologs and their function and expression in mammals and birds, with emphasis on chickens and humans.

Avian Metapneumovirus (aMPV) is a significant poultry pathogen with a global presence, primarily causing respiratory issues in turkeys. It also affects chickens, although the severity of its impact is often lessened in this species. In Morocco, aMPV has been detected in broiler flocks, prompting the need to deeply analyze circulating strains to understand better the epidemiology and develop control measures accordingly. This research focuses on the sequencing and molecular characterization of aMPV in these flocks. Additionally, aMPV isolated from turkeys displaying Turkey Rhinotracheitis (TRT) signs, were included in the study to compare the findings. RNA extracted from positive swabs was subjected to nested PCR, targeting the attachment protein of the G gene, followed by gel electrophoresis. Amplicons were purified and sequenced using the Sanger method. Bioinformatics tools facilitated sequence analyses, including BLAST for similarity searches and Mega® for phylogenetic analysis using the maximum likelihood method with 1000 bootstrap replicates. The investigation unveiled the existence of three distinct clades of the same aMPV/B strain, two of which originated from used vaccines and one from field recombination, all circulating in broilers and turkeys and indicating potential virus transmission between both poultry species. This article presents the first-ever molecular characterization of aMPV isolated from Moroccan broilers and turkeys, encompassing comprehensive investigations on its presence and subtype, and genetic characterization.

Genetically diverse influenza A viruses (IAV) circulates in wild aquatic birds with relatively frequent spillover (cases of single infections) to other mammals, but only a small proportion of outbreaks. The spillover of IAV to marine mammals such as seals have been reported throughout the last 45 years. Majority of these viruses when reached seals population cased pneumonia and death of infected animals. Until 2016, all avian influenza viruses found in seals were of low pathotype (LP) IAV. The H5Nx clade 2.4.4.4b highly pathogenic avian influenza viruses (HPAIV) were found in seals for the first time in 2016/2017. Our review highlights 45 years of AIV history in seals population, showing interesting features of different AIV subtypes and emphasis on avian-to-mammals transmission. Furthermore, we also included phylogenetic characterisation of the representative seal isolates.

The evolution of the H5 highly pathogenic avian influenza (HPAI) viruses has led to the emergence of distinct groups with genetically similar clusters of hemagglutinin (HA) sequences. In this study, a consensus H5 HA sequence was cloned into the baculovirus expression system. The HA protein was expressed in baculovirus-infected insect cells and utilized as the antigen for the production of an oil emulsion-based H5 avian influenza vaccine (rBacH5Con5Mut). 21-day old SPF chickens were immunized with this vaccine and then challenged at 21 days post-vaccination (dpv) with clade 2.3.2.1, clade 2.3.4.4 and clade 7.2 of H5 HPAI virus, respectively. The chicken sera of vaccinated chickens exhibited high hemagglutination inhibition (HI) titers against the rBacH5 vaccine antigen, while lower HI titers were observed against the different challenge virus H5 hemagglutinins. Furthermore, the rBacH5Con5Mut vaccine provided 100% protection from mortality and clinical signs. Virus isolation results showed that oropharyngeal and cloacal shedding was prevented in 100% of the vaccinated chickens when challenged with clade 2.3.2.1 and clade 2.3.4.4 H5 viruses. When the rBacH5Con5Mut vaccine candidate was administrated at one day of age, 100% protection was demonstrated against challenge of clade 2.3.4.4 virus at 3 weeks of age, indicating the potential of this vaccine for hatchery vaccination. Overall, the rBacH5Con5Mut vaccine candidate with a consensus HA antigen and a single dose can protect chickens against different clades of H5 HPAI viruses throughout the rearing period of broiler chickens without a boost, thus fulfilling the criteria for an efficacious broad-spectrum H5 avian influenza vaccine.

In 2021, amidst the COVID-19 pandemic and global food insecurity, the Nigerian poultry sector was yet exposed to highly pathogenic avian influenza (HPAI) virus and its economic challenges. Between 2021 and 2022, HPAI caused 467 outbreaks reported in 31 of the 37 administrative regions in Nigeria. In this study, we characterized the genome of 97 influenza A viruses of the subtypes H5N1, H5N2 and H5N8 identified in different agro-ecological zones and farms during the 2021-2022 epidemic. The phylogenetic analysis of the HA genes showed widespread distribution of the H5Nx clade 2.3.4.4b and similarity with the HPAI H5Nx viruses detected in Europe since late 2020. Topology of the phylogenetic trees indicates the occurrence of several independent introductions of the virus into the country followed by a regional evolution of the virus most probably linked to its persistent circulation in West African territories. An additional evidence of the evolutionary potential of HPAI viruses circulating in this region is the identification in this study of a putative H5N1/H9N2 reassortant virus in a mixed-species commercial poultry farm. Our data confirm Nigeria as a crucial hotspot for HPAI virus introduction from the Eurasian territories and reveal a dynamic pattern of avian influenza virus evolution within the Nigerian poultry population.

The domestic ducks (Anas platyrhynchos domesticus) are resistant to most of the highly pathogenic avian influenza virus (HPAIV) infections. In this study, we characterized the lung proteome and phosphoproteome of ducks infected with HPAI H5N1 virus (A/duck/India/02CA10/2011/Agartala) at 12 hr, 48 hr and 5 days post infection condition. Total 2082 proteins were differentially expressed and 320 phosphorylation sites mapping to 199 phosphopeptides corresponding to 129 proteins were identified. Functional annotation of proteome data analysis reveals activation of RIG-I-like receptor and Jak-STAT signaling pathways, that lead to induction of interferon stimulated genes (ISGs) expression. The pathway analysis of phosphoproteome datasets also confirms the activation of RIG I, Jak-STAT signaling, NF-kappa B signaling and MAPK signaling pathways in the lung tissues. The induction of ISGs proteins (STAT1, STAT3, STAT5B, STAT6, IFIT5 and PKR) establishes protective antiviral immune response in duck lung tissue. Further, the protein-protein interaction network analysis identified proteins like AKT1, STAT3, JAK2, RAC1, STAT1, PTPN11, RPS27A, NFKB1 and MAPK1 as main hub proteins that might play important roles in disease progression in ducks. Together, functional annotation of proteome and phosphoproteome datasets reveals the molecular basis of the disease progression and disease resistance mechanism in ducks infected with HPAI H5N1 virus.

The basilar arterial endothelium mediates blood-vessel relaxation, partly through release of nitric oxide (NO). Apoptosis of cerebrovascular endothelial cells is linked to high mortality rate in chickens infected with highly pathogenic avian influenza virus, but interestingly ducks exhibit greater resistance to this virus. In this study, we examined the responsiveness of duck basilar arteries (BAs) to various vasoactive substances, including 5-hydroxytryptamine (5-HT), histamine (His), angiotensin (Ang) II, noradrenaline (NA), acetylcholine (ACh), and avian bradykinin ornithokinin (OK), aiming to characterize the receptor subtypes involved and the role of endothelial NO in vitro. Our findings suggest that arterial contraction is mediated by 5-HT1 and H1 receptors, while relaxation is induced by β3-adrenergic and M3 receptors. Additionally, OK elicited a biphasic response in duck BAs, and Ang II had no effect. Endothelial NO appears to be crucial in relaxation mediated by M3 and OK receptors, but not β3-adrenergic receptors, in the duck BA. The reduced endothelial NO involvement in the receptor-mediated relaxation response in duck BAs represents a clear difference from the corresponding response reported in chicken BAs. This physiological difference may explain differences in lethality between ducks and chickens when vascular endothelial cells are infected by the virus.

The role of chemical communication in social relationships of birds is receiving growing attention but our knowledge is still scarce compared to other taxa. Previous evidence suggests that chemical cues emitted by birds may carry information about their characteristics that may be useful in a sexual selection context. However, experimental studies are needed to investigate the role of bird chemical cues in signalling quality of potential partners. We performed an experimental study aimed to disentangle whether female zebra finches, Taeniopygia guttata, use chemical cues to assess the body condition and body size of potential partners. We offered focal females the scent of two males differing in body condition and body size. Our results show that females can assess the body condition of potential partners using olfaction. However, contrary to expected in a mate choice context, our results show that females avoided the scent of the male with greater body condition and body size. Our results therefore suggest that, despite performing the study during breeding period, social interactions may be mediating the avoidance of the scent of the conspecific of the opposite sex with better body condition and body size in this gregarious species.

The Lluta River is the northernmost coastal wetland in Chile, representing a unique ecosystem and an important source of water in the extremely arid Atacama Desert. During peak season, the wetland is home to more than 150 species of wild birds and is the first stopover point for many migratory species that arrive in the country along the Pacific migratory route, representing a priority site for avian influenza virus (AIV) surveillance in Chile. The aim of this study was to determine the prevalence of influenza A virus (IAV) in the Lluta River wetland, to identify subtype diversity and to evaluate ecological and environmental factors that drive the prevalence at the study site. The wetland was studied and sampled from September 2015 to October 2020. In each visit, fresh fecal environmental samples (n = 178) of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index - NDVI) and water body size were determined. A generalized linear mixed model (GLMM) was built to assess the association between AIV prevalence and explanatory variables. Influenza positive samples were sequenced, and the host species was determined by barcoding. Of the 4,349 samples screened during the study period, overall prevalence in the wetland was 2.07% (95% CI: 1.68 to 2.55) and monthly prevalence of AIV ranged widely from 0% to 8.6%. A great diversity of hemagglutinin (HA) and neuraminidase (NA) subtypes were identified, and 10 viruses were isolated and sequenced, including low pathogenic H5, H7 and H9 strains. In addition, several reservoir species were recognized (both migratory and resident birds), including the newly identified host Chilean flamingo (Phoenicopterus chilensis). Regarding environmental variables, prevalence of AIV was positively associated with NDVI (OR=3.65, p<0.05) and with the abundance of migratory birds (OR=3.57, p<0.05). These results emphasize the importance of the Lluta wetland as a gateway to Chile for viruses that come from the Northern Hemisphere and contribute to the understanding of AIV ecological drivers.

The tri-trophic interactions between plants, insects, and insect predators and parasitoids are often mediated by chemical cues. The attraction to Herbivore-Infested Plant Volatiles (HIPVs) has been well documented for arthropod predators and parasitoids, and more recently for insectivorous birds. The attraction to plant volatiles induced by the exogenous application of methyl jasmonate (MeJA), a phytohormone typically produced in response to an attack of chewing herbivores, have provided controversial results, both in arthropod and avian predators. In this study, we aimed to examine whether potential differences in the composition of bouquets of volatiles produced by Herbivore-infested and MeJA-treated Pyrenean oak trees (Quercus pyrenaica) were related to differential avian attraction, as results from a previous study suggested. Results showed that the overall emission of volatiles produced by MeJA-treated and Herbivore-infested trees did not differ, and were higher than emissions of Control trees, although MeJA treatment showed more significant reaction and released several specific compounds in contrast to Herbivore-induced trees. These slight differences in the volatile composition may explain why avian predators were not so attracted to MeJA-treated trees as observed in a previous study in this plant-herbivore system. Unfortunately, the lack of avian visits to the experimental trees in the current study does not allow us to confirm this result and points out the need to perform more robust predator studies.

In March 2013, a novel avian influenza A H7N9 virus was emerged in China, which cause rapidly progressive pneumonia and with a high fatality rate. Serologic studies to evaluate neutralizing antibodies of infected patients and birds are invaluable tools for immunogenicity research of H7N9 and epidemiological investigation. Conventional neutralization assays are laborious and time-consuming which also hampered by biosafety requirement. In this study, We construct and produce pseudovirus bearing the full-length hemagglutinin (HA) of H7N9 virus in the Env-defective, luciferase-expressing HIV-1 backbone. The production of lentiviral pseudovirus was analysed by HA gene specific real-time reverse-transcription PCR, transmission electron microscopy (TEM), and Western Blot assay to prove the nucleic acid replication, the morphology of virus, and the expression of HA protein in pseudovirus. After that pseudovirus based inhibition assay was established to detect neutralizing antibodies of a panel of serum samples. Our results demonstrated that H7N9 pseudovirus which had single-cycle infection was generated. By comparing the neutralization antibody titers, pseudovirus based neutralization test could be recognized as an alternative of conventional microneutralization (MN). Hence, we conclude that it is possible to use pseudovirus inhibition assay to screen sera samples, as well as evaluate vaccine-induced neutralizing antibodies against H7N9 virus.

Highly pathogenic (HP) avian influenza viruses (AIVs) are naturally restricted to H5 and H7 subtypes with a polybasic cleavage site (CS) in the hemagglutinin (HA) and any AIV with an intravenous pathogenicity index (IVPI) ≥1.2. Only few non-H5/H7 viruses fulfill the criteria of HPAIVs; nevertheless, it remains unknown why these viruses did not spread in domestic birds. In 2012, a unique H4N2 virus with a polybasic CS 322PEKRRTR/G329 was isolated from quails in California which, however, was avirulent in chickens. This is the only known non-H5/H7 virus with four basic amino acids in the HACS. Here, we investigated the virulence of this virus in chickens after expansion of the polybasic CS by substitution of T327R (322PEKRRRR/G329) or T327K (322PEKRRKR/G329) with or without reassortment with HPAIVs H5N1 and H7N7. The impact of single mutations or reassortment on virus fitness in vitro and in vivo was studied. Efficient cell culture replication of T327R/K carrying H4N2 viruses increased by trypsin, particularly in MDCK cells, and reassortment with HPAIV H5N1. Likewise, replication, virus excretion and bird-to-bird transmission of H4N2 was remarkably compromised by the CS mutations, but restored after reassortment with HPAIV H5N1, although not with HPAIV H7N7. Viruses carrying the H4-HA with or without R327 or K327 mutations and the other gene segments from HPAIV H5N1 exhibited high virulence and efficient transmission in chickens. Together, increasing the number of basic amino acids in the H4N2 HACS was detrimental for viral fitness particularly in vivo but compensated by reassortment with HPAIV H5N1. This may explain the absence of non-H5/H7 HPAIVs in poultry.

A novel utilization of passive samplers has emerged as a promising method for rapidly assessing the presence of Avian Influenza Virus (AIV), particularly H5N1, which is known for its shedding from infected birds. The passive torpedo sampler procedure for identifying presence of AIV, a carryover from the successful technology used to monitor COVID concentrations in wastewater, is demonstrated in application for detection of AIV. While the potential benefits of the application of this technology are significant, challenges remain that must be addressed to maximize its effectiveness. H5N1 poses a substantial risk due to its ability to survive in the environment for extended periods, with infected birds excreting the virus in feces and saliva for up to ten days. By leveraging this advanced sampling technique, the opportunity exists to enhance surveillance efforts and better understand the dynamics of this virus in avian populations. The torpedo approach for detection of AIV viruses has the potential to increase the surveillance coverage, is less expensive than current procedures, and provides the opportunity for improved accessibility and spatial coverage of areas near chicken barns.

An outbreak of esophagitis and ingluvitis caused by Salmonella Typhimurium in passerines seized from illegal wildlife trafficking is described. This illegal activity causes stress and leads to lowered immunity in the birds. Additionally, inadequate hygiene conditions predispose the birds to diseases such as salmonellosis. Few studies report the occurrence of Salmonella-induced lesions in the esophagus and crop of wild birds; thus, this study aimed to describe the disease in these species, investigate its presence in the environment, and determine the antimicrobial resistance profile. Three birds of the genus Sporophila were necropsied. In the esophagus and crop, yellowish plaques corresponding to necrosis with bacterial aggregates were observed. Salmonella spp. was isolated from these lesions, with genus confirmation via MALDI-TOF. Environmental samples were collected from the enclosures and cages where the animals were quarantined, and the same bacterium was isolated. In two birds, the serotype S. Typhimurium was identified. Antibiograms performed on the strains from the birds and the environment revealed resistance to antibiotics in the classes of Penicillins, Sulfonamides, Aminoglycosides, Monobactams, Tetracyclines, and first and third-generation Cephalosporins. To the authors' knowledge, this is the first report of this agent causing death in Sporophila due to esophagitis and ingluvitis. It is also the first report of salmonellosis in three species of passerines in Brazil. The study underscores the importance of understanding the pathogens circulating in wild animals, especially within the context of One Health.

Backyard chickens often suffer from foot pad dermatitis (FPD), a condition exacerbated by poor husbandry, nutritional deficiencies, and obesity. Pressure-relieving bandages, commonly used in treatment of FPD, are impractical for outdoor chickens as they quickly become wet and dirty, necessitating daily changes which are often unfeasible. This retrospective study explores the use of custom-fit silicone shoes, created via 3D-printed molds, as an alternative to traditional bandages. CT scans were used to design shoes, adapted from a design used for birds of prey. Over three years, 16 chickens with varying degrees of FPD were treated. The results demonstrated that sili-cone shoes were an effective treatment for FPD, allowing outdoor activity, and facilitated daily lesion care without frequent bandage changes. The median shoe-wearing period was 14 days, and most owners provided positive feedback. Despite some attachment issues, the occurrence of sec-ondary pressure marks and feather regrowth challenges, the silicone shoes offered better ventila-tion, reusability, and consistent pressure relief compared to traditional bandages. This study con-cludes that silicone shoes are a viable solution for managing FPD in backyard chickens, promoting faster healing and improved owner compliance.

We investigated the effect of C. psittaci and H9N2 coinfection on HD11 cells in vitro, expecting to find the potential pathogenesis of airsacculitis caused by co-infection of C. psittaci and H9N2. HD11 cells were infected with C. psittaci and/or H9N2 in a different order, and effects of the co-infection on iNOS expression and activity, NO synthesis, cell phagocytosis, and cytokines levels in HD11 cells were determined. Results showed that C. psittaci and H9N2 can significantly aggravate the mortality of HD11 cells compared to the effects of infection with one pathogen alone. In addition, infection with C. psittaci can increase the replication of H9N2 in HD11 cells, whereas decrease the iNOS level and enzyme activity as well as NO concentration of HD11 cells by H9N2 infection. We also found that C. psittaci infection alone can significantly decrease the phagocytosis of HD11 cells, compared to H9N2 infection alone. Furthermore, infection with C. psittaci can increase the mRNA expressions of type Th2 cytokines IL-6 and IL-10 of HD11 cells by H9N2 infection. All the above data indicated that primary C. psittaci infection is able to aggravate H9N2 invasion by down-regulating functions of HD11 cells

A pandemic happens when a novel influenza A virus is able to infect and transmit efficiently to a new, distinct host species. Although the exact timing of pandemics is uncertain, it is known that both viral and host factors play a role in their emergence. Species-specific interactions between the virus and the host cell determine the virus tropism. These include binding and entering cells, replicating the viral RNA genome within the host cell nucleus, assembling, maturing, and releasing the virus to neighbouring cells, tissues, or organs before transmitting it between individuals. Influenza has a vast and antigenically varied reservoir. In wild aquatic birds, the infection is typically asymptomatic. Avian influenza virus (AIV) can cross into new species, and occasionally, it can acquire the ability to transmit from human to human. A pandemic might occur if a new influenza virus acquires enough adaptive mutations to maintain transmission between people. This review highlights the key determinants AIV must achieve to initiate a human pandemic and describes how AIV mutates to establish tropism and stable human adaptation. Understanding the tropism of AIV may be crucial in preventing virus transmission in humans and may help design vaccines, antivirals and therapeutic agents against the virus.

Over the last decade, highly pathogenic avian influenza (HPAI) has severely affected poultry production systems across the globe. In particular, massive pre-emptive depopulation of all poultry within the certain distance has raised concerns regarding animal welfare and food security. Thus, alternative approaches to reducing unnecessary depopulation, such as risk-based depopulation, are highly demanded. This paper proposes a data-driven method to generate a rule table and risk score for each farm to identify preventive measures against HPAI. To evaluate the proposed method, 105 cases of HPAI occurring in a total of 381 farms in Jeollanam-do from 2014 to 2023 were evaluated. The accuracy of preventive measure identification was assessed for each case using both the conventional culling method and the proposed data-driven method. The evaluation showed that the proposed method achieved an accuracy of 84.19%, significantly surpassing the previous 10.37%. The result was attributed to the proposed method reducing the false-positive rate by 83.61% compared with the conventional method, thereby enhancing the reliability of identification. The proposed method is expected to be utilized in selecting farms for monitoring and management of HPAI.

The Influenza A virus (IAV) is a highly infectious virus that poses a significant threat to global public health and food supplies. The current subtype of avian influenza virus (AIV), H5N1, is being closely monitored worldwide due to its unprecedented spread from Europe to North America and now to Central and South America. This review summarizes recent updates on the evolution of the different IAV subtypes in birds and mammals including humans, in Chile. The distribution and spread of AIV H5N1 in Chile indicated a complex interplay between ecological and human factors in that it was negatively correlated with distance to the closest urban center and precipitation and temperature seasonality. It is evident that highly pathogenic avian influenza (HPAI) H5N1 in Chile was introduced from North America via the Atlantic migratory flyways as opposed to local transmission from other countries in South America. The presence of these viruses in Chile underscores the need for increased biosecurity on poultry farms and continuous genomic surveillance approaches to understand and control AIVs in both wild and domestic bird populations in Chile.

In contrast to previous incursions of highly pathogenic H5 viruses, H5N8 clade 2.3.4.4b caused numerous lethal infections in white-tailed sea eagles (Haliaeetus albicilla) in Germany during the winter 2016/2017. Until April 2017, 17 HPAIV H5N8-positive white-tailed sea eagles had been detected (three alive and 14 dead). Mainly young eagles died (before reaching the adult plumage at 5 years), often with severe neurological symptoms, where histopathology revealed mild to moderate, oligo- to multifocal necrotizing polioencephalitis. Lethal lead (Pb) concentrations, proven as main mortality factor of the sea eagles could be ruled out since values measured in liver or kidney tissue were all within background levels (< 1 ppm). Since the fall of 2016, the epizootic of HPAIV H5 clade 2.3.4.4b reportedly induced, for the first time, fatal disease in European white-tailed see eagles. The virus strain may become a new threat to a highly protected species across its distribution range in Eurasia. Positive cloacal swaps have proven that the eagles can spread the virus with their faeces.

The introduction of HPAI H5N1 clade 2.3.4.4b viruses to North America in late 2021 resulted in avian influenza outbreaks in poultry, mortality events in many wild bird species, and spillover into many mammalian species. Reassortment events with North American low pathogenic virus were identified as early as February 2022 and over 100 genotypes have been characterized. Such diversity increases the complexity and time required for monitoring virus evolution. Here, we performed ordination and clustering analyses on sequence data from H5N1 viruses identified in North America between January 2020 to December 2023 to visualize virus genotypic diversity in poultry and wildlife populations. Our results reveal that ordination and cluster-based approaches can complement traditional phylogenetic analyses specifically for the preliminary assignment of H5N1 viruses to genotypic groups or to identify novel genotypes. Our study expands current knowledge on genotype diversity of H5N1 viruses in North America and describes a rapid approach for early virus genotype assignment.

Pigeon paramyxovirus serotype 1 (PPMV-1), primarily originating from racing pigeons, has become a global panzootic, spreading to poultry and wild birds, thus posing a threat to the poultry industry. Egypt uses both inactivated pigeon paramyxovirus (PPMV-1) and conventional Newcastle disease virus (NDV) vaccines to protect pigeons. However, the impact of prevalent strains and the effectiveness of available vaccines in pigeons in Egypt are unclear. This study investigates the virulence of PPMV-1 isolated from vaccinated pigeons in Sharkia, Egypt (Pigeon/ Egypt/Sharkia-19/2015/KX580988). Ten-day-old specific-pathogen-free embryonated chicken eggs infected with this strain exhibited a mean death time (MDT) of 86.4±5.88 hours. The intracerebral pathogenicity index (ICPI) in day-old chicks was 0.8, while pigeons experienced an ICPI of 0.96 and an intravenous pathogenicity index (IVPI) of 2.11. These findings classify the strain as virulent and velogenic. Experimental infection with this PPMV-1 strain at 106 EID50/0.1 ml resulted in a 62.5% mortality rate in pigeons, displaying nervous and enteric distress. The virus caused extensive lesions in visceral organs, with strong immunohistochemistry signals in all examined organs, indicating the systemic spread of the virus concurrent to its neurotropic and viscerotropic tropism. Furthermore, vaccination using inactivated PPMV-1 and live NDV LaSota vaccine regimen protected 100% of pigeons against mortality, while a single NDV LaSota vaccine provided 62.5% protection. The PPMV alone or combined with NDV LaSota induced protective levels of hemagglutination inhibition antibody titers and reduced virus shedding from buccal and cloacal cavities. These findings suggest that using both inactivated PPMV-1 (G-VI) and live attenuated NDV (LaSota) vaccines is an effective prophylactic regimen for preventing and controlling PPMV-1 and NDV in pigeons, thereby reducing the risk of interspecies transmission.

Avian influenza viruses (AIVs) are highly contagious respiratory viruses of birds, lead-ing to significant morbidity and mortality globally and causing substantial economic losses to the poultry industry. Since their first isolation in 2013, the Asian-origin H5N1 highly pathogenic avian influenza viruses (HPAI) of clade 2.3.4.4b have undergone unprecedented evolution and re-assortment of internal gene segments and have spread to Asia, Europe, Africa, and America, caus-ing outbreaks in all the poultry categories. Novel epidemiological and pathobiological character-istics, distinct from other clades, are specific of clade 2.3.4.4b viruses. Wild waterfowl, the natu-ral reservoir of AIVs, are frequently found infected with clade 2.3.4.4b viruses, which can also cause high morbidity and mortality in these birds. The sustained clade 2.3.4.4b virus circulation in waterfowl has also led to virus infection in other wild bird species, with implications for the conservation of endangered species. Furthermore, clade 2.3.4.4b viruses have been isolated in var-ious wild and domestic mammals worldwide, and critical mutations related to virus adaptation to mammalian species have been identified, raising concerns about virus spillover to humans. The main clinical signs, and anatomopathological findings associated to clade 2.3.4.4b virus infection in birds and non-human mammals are hereby summarized.

Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid (BXA), a new class of inhibitors for the influenza virus cap-dependent endonuclease, has been confirmed in vitro, but it has not yet been fully characterized. Here, the efficacy of BXA against HPAIVs, including recent H5N8 variants, was assessed in vitro. The antiviral efficacy of baloxavir marboxil (BXM) in H5N1 virus-infected mice was also investigated. BXA exhibited similar in vitro activities against H5N1, H5N6, and H5N8 variants tested in comparison with seasonal and other zoonotic strains. Compared with oseltamivir phosphate (OSP), BXM monotherapy in mice infected with the H5N1 HPAIV clinical isolate, the A/Hong Kong/483/1997 strain, also caused a significant reduction in viral titers in the lungs, brains, and kidneys, thereby preventing acute lung inflammation and reducing mortality. Furthermore, compared with BXM or OSP monotherapy, combination treatments with BXM and OSP using a 48-hour delayed treatment model showed a more potent effect on viral replication in the organs, accompanied by improved survival. In conclusion, BXM has a potent antiviral efficacy against H5 HPAIV infections.

Environmental DNA (eDNA) is an increasingly used non-invasive molecular tool for detecting species presence and monitoring populations. In this article, we review the current state of non-avian reptile eDNA work in aquatic systems, as well as present a field experiment on detecting the presence of painted turtle (Chrysemys picta) eDNA. Thus far, turtle and snake eDNA studies have been successful mostly in detecting the presence of these animals in field conditions. However, some instances of low detection rates and non-detection occur for these non-avian reptiles, especially for squamates. We explored this matter by sampling lentic ponds with different densities (0 kg/ha, 6 kg/ha, 9 kg/ha, and 13 kg/ha) of painted turtles over three months, attempting to detect differences in eDNA accumulation using a qPCR assay. Only one sample of the highest density pond readily amplified eDNA. Yet, estimates of eDNA concentration from pond eDNA were rank-order correlated with turtle density. We present a “shedding hypothesis”–the possibility that animals with hard, keratinized integument do not shed as much DNA as mucus-covered organisms–as a potential challenge for turtle eDNA studies. Despite challenges with eDNA inhibition and availability in water samples, we remain hopeful that eDNA can be used to detect freshwater turtles in the field. We provide key recommendations for biologists wishing to use eDNA methods for detecting non-avian reptiles.

Avian Influenza viruses (AIVs) has posed a significant pandemic threat since their discovery. This review mainly focuses on the epidemiology, virology, and pathogenesis, and treatments of avian influenza viruses. We delve into the global spread, past pandemics, clinical symptoms, severity, and immune response related to AIVs. The review also discusses various control measures, including antiviral drugs, vaccines, and potential future directions in influenza treatment and prevention. Lastly, by summarizing the insights from the previous pandemic control, this review aims to direct effective strategies for managing future influenza pandemics.

In this study, we report the first outbreak of highly pathogenic avian influenza (HPAI) A H5N8, clade 2.3.4.4b in Kosovo on May 19, 2021. The outbreak consisted of three temporal phases: May–June 2021, September–November 2021, and January–May 2022. In total, 32 backyard and 10 commercial holdings tested positive for the virus, affecting 179,198 poultry. Interestingly, the third and last phase of the outbreak coincided with the massive H5N1 clade 2.3.4.4b epidemic in Europe. Phylogenetic analyses of 28 viral strains from Kosovo revealed that they were closely related to the H5N8 clade 2.3.4.4.b viruses that have been circulating in Albania, Bulgaria, Croatia, Hungary, and Russia in early 2021. Whole genome sequencing of the 25 and partial sequencing of 3 H5N8 viruses from Kosovo showed high nucleotide identity, forming a distinctive cluster and suggesting a single introduction. The results of the network analysis were in accordance with the three epidemic waves and suggested that the viral diffusion could have been caused by secondary spreads among farms and/or different introductions of the same virus from wild birds. The persistent circulation of the same virus over a one-year period highlights the potential risk of the virus becoming endemic, especially in settings with non-adequate biosecurity.

During autumn/winter in 2016 – 2017 and 2020 – 2021, highly pathogenic avian influenza viruses (HPAIV) caused severe outbreaks in Germany and Europe. Multiple clade 2.3.4.4b H5 HPAI subtypes were responsible for increased mortality in wild birds and high mortality and massive losses in the poultry sector. To clarify putative entry sources and delineate interconnections between outbreaks in poultry holdings and wild birds, we applied whole-genome sequencing and phylodynamic analyses combined with the results of epidemiological outbreak investigations. Varying outbreak dynamics of the distinct reassortants allowed for the identification of individual, putatively wild bird-mediated entries into backyard holdings, several clusters comprising poultry holdings, local virus circulation for several weeks, direct farm-to-farm transmission and potential reassortment within a turkey holding with subsequent spill-over of the novel reassorted virus into the wild bird population. Whole-genome sequencing allowed for allowed for a unique high-resolution molecular epidemiology analysis of HPAIV H5Nx outbreaks, recommended to be used as a standard tool. The presented detailed account of the genetic, temporal and geographical characteristics of the recent German HPAI H5Nx situation emphasizes the role of poultry holdings as an important source of novel genetic variants and reassortants.

Emerging RNA virus infections are a growing concern among domestic bird and poultry industries due to the severe impact it can have on the flock health and economic livelihoods. Avian paramyxoviruses (APMV) are pathogenic, negative sense RNA viruses that cause serious infections in the respiratory and central nervous system. APMV was detected in multiple avian species during the 2017 migration season in Ukraine, and studied using PCR, virus isolation, and sequencing. Of the 4090 wild bird samples, eleven swabs were isolated in chicken embryos and identified for APMV serotype by hemagglutinin inhibition test: APMV-1, APMV-4, APMV-6, APMV-7. At a variety of sites in Ukraine we characterized the virulence of the virus and further analyzed and predicted the potential risks of spillover to immunologically naïve populations. RNA was extracted and amplified using a multiplex-tiling primer approach to encompass full cDNA genomes. Full-length APMV-1 (n=5) and APMV-6 (n=2) genomes were sequenced on an Oxford Nanopore MinION device in Ukraine. All APMV-1 and APMV-6 fusion (F) proteins possessed a monobasic cleavage site, suggesting these APMV 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.

Pollution, urbanization and technological advancements have posed stress on the ecosystem and its matrices. Globally, pollutants are observed in all compartments of ecological communities which affect the integrity of the atmosphere, hydrosphere, lithosphere and biosphere. Xenobiotics bioaccumulate and biomagnify across trophic levels or webs. Heavy metals have been implicated in impacts towards biodiversity and environmental declination. In Nigeria, wastes issues are a cause of concern and landfilling or are waste disposal approaches that cause deleterious effects such as depauperation of diversity and species decline, prompting the non-invasive ecotoxicological hazard assessments. Feathers were used to assess concentration levels of 13 metals (Fe, Mn, Zn, Cu, Co, Cr, Cd, Pb, Ni, Al, B, Se and Hg) using fast atomic absorption spectrophotometer (FAAS), one-way ANOVA was used in comparing variations in mean concentrations across trophic levels, diversity indices and point count methods were used to estimate diversity and abundance. Four avian species were assessed Hirundo aethiopica (insectivore), Streptoptelia senegalensis (granivore), Turdus pelios (omnivore), and Anthus leucophrys. (insectivore). Observed concentrations of important metals like iron were high with the insectivores having the highest concentrations of iron (2.6985 ± 0.1975 ppm) and granivores having the lowest (2.0100 ± 0.3172 ppm). The insectivores had the highest concentrations for cadmium, cobalt and chromium (0.0005 ± 0.0005ppm), nickel (at 00.0012 ± 0.0017 ppm) and least was observed in the granivores (0.0003 ± 0.0006 ppm). Selenium concentrations were quite high in insectivores (0.0775 ± 0.0035 ppm) and lowest in granivores (0.0433 ± 0.0015 ppm) likewise mercury for insectivores (0.0280 ± 0.0010 ppm) and granivores (0.0213 ± 0.0015 ppm). From the study, it is apparent that landfills are sources of pollution and poor management of wastes can affect biota (causing effects such as asymmetry and bioaccumulation) and ecosystem balance. The observation of heavy metals in the feathers serve as good sentinels due to their trophic levels and could be signs for what could be yet to occur. The heavy metal concentrations were significantly different at p < 0.05.

A brief overview of the past and present trajectories made by the A(H5N1) avian influenza virus among domestic birds, avian and mammalian wildlife species and humans is presented here, thereby taking into special account the 2.3.4.4b clade of the virus recently emerged in several geographic areas of the globe.

Antimicrobial peptides provide a powerful toolkit for combating multidrug resistance. Combatting eukaryotic pathogens is complicated by the fact, the intracellular drug targets in the eukaryotic pathogen are frequently homologs of cellular structures of vital importance in the host organism. The entomopathogenic bacteria, (symbionts of entomopathogenic nematode species), release a series of non-ribosomal templated antimicrobial peptides, some may be potential drug candidates. The ability of an entomopathogenic nematode /entomopathogenic bacterium symbiotic complex to survive in a given polyxenic milieu is a coevolutionary product, explaining that those gene complexes which are responsible for the biosynthesis of different non-ribosomal templated antimicrobial protective peptides (including those which are potently capable to inactivate the protist mammalian -pathogen Leishmania and the gallinaceous bird pathogen Histomonas) are co-regulated. Our approach is based on comparative antimicrobial bioassays of the culture media of the wild-type and regulatory mutant strains. We concluded that Xenorhabdus budapestensis and X. szentirmaii are excellent sources of non-ribosomal templated antimicrobial peptides, that are efficient antagonists of the mentioned pathogens. Data on selective cytotoxicity of different cell-free culture media encourages us to forecast that the recently discovered “easy-PACId” research strategy is suitable for constructing EPB strains producing and releasing single, harmless, non-ribosomal templated antimicrobial peptides with considerable drug, (probiotic) -candidate potential.