Avian Disease Research Articles

SLC1A3 facilitates Newcastle disease virus replication by regulating glutamine catabolism

ABSTRACT As obligate intracellular parasites, viruses rely completely on host metabolic machinery and hijack host nutrients for viral replication. Newcastle disease virus (NDV) causes acute, highly contagious avian disease and functions as an oncolytic agent. NDV efficiently replicates in both chicken and tumour cells. However, how NDV reprograms host cellular metabolism for its efficient replication is still ill-defined. We previously identified a significantly upregulated glutamate transporter gene, solute carrier family 1 member 3 (SLC1A3), during NDV infection via transcriptome analysis. To investigate the potential role of SLC1A3 during NDV infection, we first confirmed the marked upregulation of SLC1A3 in NDV-infected DF-1 or A549 cells through p53 and NF-κB pathways. Knockdown of SLC1A3 inhibited NDV infection. Western blot analysis further confirmed that glutamine, but not glutamate, asparagine, or aspartate, was required for NDV replication. Metabolic flux data showed that NDV promotes the decomposition of glutamine into the tricarboxylic acid cycle. Importantly, the level of glutamate and glutaminolysis were reduced by SLC1A3 knockdown, indicating that SLC1A3 propelled glutaminolysis for glutamate utilization and NDV replication in host cells. Taken together, our data identify that SLC1A3 serves as an important regulator for glutamine metabolism and is hijacked by NDV for its efficient replication during NDV infection. These results improve our understanding of the interaction between NDV and host cellular metabolism and lay the foundation for further investigation of efficient vaccines.

Risk Factors Associated with Avian Influenza Subtype H9 Outbreaks in Poultry Farms of Central Lowland Nepal.

Low pathogenic avian influenza (LPAI) of subtype H9 outbreaks have been frequently occurring in major commercial hubs of Nepal including Chitwan, a central lowland area, causing substantial economic losses to the farmers. However, the risk factors associated with these outbreaks have been poorly understood, and hence, this case-control study was conducted in Chitwan, Nawalpur, and Makawanpur districts of Nepal from October 2019 to March 2020. A total of 102 farms were selected in which 51 were case farms, and 51 were controls. Case farms were avian influenza (AI)-subtype-H9-confirmed farms through polymerase chain reaction (PCR) assays on poultry samples. Control farms included farms that were AI-negative in the antigen test brought to the National Avian Disease Investigation Laboratory, Chitwan, for diagnosis during the study period. Each farm was visited to collect information using a semi-structured questionnaire. A total of 25 variables representing farm characteristics and biosecurity measures were considered as potential risk factors. The final multivariable model showed that distance of less than 0.5 km from the main road (OR = 4.04, 95% CI = 1.20–13.56, p = 0.023), distance of less than 1 km from a nearest infected farm (OR = 76.42, 95% CI = 7.17–814.06, p = 0.0003), and wild birds coming around the farm (OR = 6.12, 95% CI = 1.99–18.79, p = 0.0015) were risk factors for avian influenza type H9, whereas using apron or separate cloth inside the shed (OR = 0.109, 95% CI = 0.020–0.577, p = 0.0092) was shown to reduce the risk of farms being positive for AI subtype H9. These findings suggest that due consideration should be given to site selection while establishing the farms and the importance of implementing appropriate biosecurity measures, such as using separate cloth inside the shed and preventing the entry of wild birds inside the farm to reduce the potential risk of introduction of avian influenza type H9 to their poultry farms.

Alterations in bone marrow microRNA expression profiles on infection with avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is one of the most common avian bacterial diseases globally. The bone marrow is a reservoir of immature immune cells. To elucidate the role of bone marrow microRNAs (miRNAs) in regulating the host response to APEC infection, we performed miRNA-seq to investigate alterations in the expression of bone marrow miRNAs in three groups of specific pathogen-free chickens: non-challenged (NC) and challenged with APEC for 12 h (C12) and 24 h (C24). Twenty and 19 differentially expressed miRNAs (fold change >2, P < 0.01) were identified on comparing the NC and C12 and the NC and C24 groups, respectively. On functional annotation analysis of target genes of differentially expressed miRNAs, we found that the gene ontology term “immune system process” was significantly enriched at both 12 h and 24 h; moreover, several important signaling pathways were triggered in response to APEC infection, such as MAPK, cGMP-PKG, Notch, and cAMP pathways. In addition, we performed reverse transcription quantitative real-time PCR (qRT-PCR) to validate the differential expression of miRNAs. qRT-PCR data were similar to the sequencing data. On constructing an miRNA–target gene network, gga-miR-2127, gga-miR-6643-5p, and gga-miR-6567-3p were found to potentially play a vital role in the immune process. Overall, our findings provide deeper insights into miRNA transcriptome changes involved in the immune response of the chicken bone marrow to APEC infection.

Analysis of miRNA Expression Profiling of RIP2 Knockdown in Chicken HD11 Cells When Infected with Avian Pathogenic E. coli (APEC).

Colibacillosis is an acute and chronic avian disease caused by avian pathogenic E. coli (APEC). Previous studies have demonstrated that RIP2 plays a significant role in APEC infection. Moreover, increasing evidence indicates that microRNAs (miRNAs) are involved in host–pathogen interactions and the immune response. However, the role of miRNAs in the host against APEC infection remains unclear. Herein, we attempted to reveal new miRNAs potentially involved in the regulation of the immune and inflammatory response against APEC infection, with a particular focus on those possibly correlated with RIP2 expression, via miRNA-seq, RT-qPCR, Western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 93 and 148 differentially expressed (DE) miRNAs were identified in the knockdown of RIP2 cells following APEC infection (shRIP2+APEC) vs. knockdown of RIP2 cells (shRIP2) and shRIP2 vs. wild-type cells (WT), respectively. Among those identified DE miRNAs, the biological function of gga-miR-455-5p was investigated. It was found that gga-miR-455-5p regulated by RIP2 was involved in the immune and inflammatory response against APEC infection via targeting of IRF2 to modulate the expression of type I interferons. Additionally, RIP2 could directly regulate the production of the type I interferons. Altogether, these findings highlighted the crucial role of miRNAs, especially gga-miR-455-5p, in host defense against APEC infection.

Immunohistochemical and molecular detection of avian neoplastic disease viruses in layer chickens from poultry farms in Northwestern and Northcentral Nigeria

Immunohistochemical and molecular detection of avian neoplastic disease viruses in layer chickens from poultry farms in Northwestern and Northcentral Nigeria

Effects of urban sugar water feeding on bird body condition and avian diseases

Garden bird sugar water feeding is increasingly popular worldwide, but little is known about its effects on bird health and associated diseases. There is a concern that feeding stations can accumulate pathogens and facilitate pathogen transmission between individuals, resulting in adverse effects on body condition of visiting birds. We tested the effects of sugar water feeding in urban New Zealand backyards by sampling target species for multiple infections and comparing bird body condition. For this, we compared backyards with and without sugar water feeders and again compared existing sugar water feeders with various sugar concentrations in two cities and in two seasons. Birds caught in gardens with sugar water feeders had poorer body condition; however, birds had better body condition in the city with the warmer climate (Auckland), during summer, and in gardens with high (≥20%) sugar concentration in sugar water feeders in winter. All screening tests for Chlamydia psittaci and Salmonella spp. returned negative results. Avian poxvirus prevalence in tauhou ( Zosterops lateralis) was four times higher in the city with a warmer climate. The likelihood of lice infection in tauhou was lower in gardens with feeders, in the warmer city, in summer, and at feeders with higher sugar concentrations. In tūī ( Prosthemadera novaeseelandiae), the likelihood of lice infection decreased with an increase in sugar concentration. Coccidia infection was 4.25 times higher in tauhou in gardens with feeders. Despite the identified risks associated with sugar water feeding, there appear to be potential benefits for native nectarivorous birds, specifically in winter.

Rapid, Sensitive, and Species-Specific Detection of Conventional and Recombinant Herpesvirus of Turkeys Vaccines Using Loop-Mediated Isothermal Amplification Coupled With a Lateral Flow Device Readout.

Marek's disease, an economically important disease of chickens caused by virulent serotype 1 strains of the Mardivirus Marek's disease virus (MDV-1), is effectively controlled in the field by live attenuated vaccine viruses including herpesvirus of turkeys (HVT)—both conventional HVT (strain FC126) and, in recent years, recombinant HVT viruses carrying foreign genes from other avian viruses to protect against both Marek's disease and other avian viral diseases. Testing to monitor and confirm successful vaccination is important, but any such test must differentiate HVT from MDV-1 and MDV-2, as vaccination does not prevent infection with these serotypes. End-point and real-time PCR tests are widely used to detect and differentiate HVT, MDV-1 and MDV-2 but require expensive specialist laboratory equipment and trained operators. Here, we developed and validated two tube-based loop-mediated isothermal amplification tests coupled with detection by lateral flow device readout (LAMP-LFD): an HVT-specific test to detect both conventional and recombinant HVT strains, and a second test using novel LAMP primers to specifically detect the Vaxxitek® recombinant HVT. Specificity was confirmed using DNA extracted from virus-infected cultured cells, and limit of detection was determined using plasmid DNA carrying either the HVT or Vaxxitek® genome. The LAMP-LFD tests accurately detected all HVT vaccines, or Vaxxitek® only, in crude DNA as well as purified DNA extracted from field samples of organs, feathers, or poultry house dust that were confirmed positive for HVT by real-time PCR. These LAMP-LFD tests have potential for specific, rapid, simple, and inexpensive detection of HVT vaccines in the field.

Vaccines against Major Poultry Viral Diseases: Strategies to Improve the Breadth and Protective Efficacy.

The poultry industry is the largest source of meat and eggs for human consumption worldwide. However, viral outbreaks in farmed stock are a common occurrence and a major source of concern for the industry. Mortality and morbidity resulting from an outbreak can cause significant economic losses with subsequent detrimental impacts on the global food supply chain. Mass vaccination is one of the main strategies for controlling and preventing viral infection in poultry. The development of broadly protective vaccines against avian viral diseases will alleviate selection pressure on field virus strains and simplify vaccination regimens for commercial farms with overall savings in husbandry costs. With the increasing number of emerging and re-emerging viral infectious diseases in the poultry industry, there is an urgent need to understand the strategies for broadening the protective efficacy of the vaccines against distinct viral strains. The current review provides an overview of viral vaccines and vaccination regimens available for common avian viral infections, and strategies for developing safer and more efficacious viral vaccines for poultry.

Heterologous synthesis of N and M fragments of capsid protein VP2 of avian infectious bursal disease virus in yeast Pichia pastoris

BACKGROUND: Infectious bursal disease is one of the most common and economically important viral diseases of birds. Vaccination is currently the most effective way to control IBD. Subunit vaccines contain only the immunogenic protein of the pathogen or its fragments, but do not contain other proteins, lipopolysaccharides, toxins, which avoids vaccination side effects.&#x0D; AIM: The aim of the work was to obtain yeast Pichia pastoris strains that synthesize and secrete the fragments of major coat protein VP2 of the infectious bursal disease virus.&#x0D; MATERIALS AND METHODS: The DNA sequences encoding the N and M fragments of VP2 protein, were cloned under the control of the AOX1 gene promoter and integrated into the genome of P. pastoris strains X-33 (mut+) and GS115 (his4).&#x0D; RESULTS: The analysis of proteins secreted by the obtained strains revealed the presence of additional proteins with a molecular weights corresponding to the target proteins.&#x0D; CONCLUSIONS: Thus, the obtained strains of P. pastoris producers of N and M fragments of VP2 protein can be used for antigen production to create a subunit vaccine against avian IBD.

Human Wharton's Jelly Mesenchymal Stem Cells Secretome Inhibits Human SARS-CoV-2 and Avian Infectious Bronchitis Coronaviruses.

Human SARS-CoV-2 and avian infectious bronchitis virus (IBV) are highly contagious and deadly coronaviruses, causing devastating respiratory diseases in humans and chickens. The lack of effective therapeutics exacerbates the impact of outbreaks associated with SARS-CoV-2 and IBV infections. Thus, novel drugs or therapeutic agents are highly in demand for controlling viral transmission and disease progression. Mesenchymal stem cells (MSC) secreted factors (secretome) are safe and efficient alternatives to stem cells in MSC-based therapies. This study aimed to investigate the antiviral potentials of human Wharton’s jelly MSC secretome (hWJ-MSC-S) against SARS-CoV-2 and IBV infections in vitro and in ovo. The half-maximal inhibitory concentrations (IC50), cytotoxic concentration (CC50), and selective index (SI) values of hWJ-MSC-S were determined using Vero-E6 cells. The virucidal, anti-adsorption, and anti-replication antiviral mechanisms of hWJ-MSC-S were evaluated. The hWJ-MSC-S significantly inhibited infection of SARS-CoV-2 and IBV, without affecting the viability of cells and embryos. Interestingly, hWJ-MSC-S reduced viral infection by >90%, in vitro. The IC50 and SI of hWJ-MSC secretome against SARS-CoV-2 were 166.6 and 235.29 µg/mL, respectively, while for IBV, IC50 and SI were 439.9 and 89.11 µg/mL, respectively. The virucidal and anti-replication antiviral effects of hWJ-MSC-S were very prominent compared to the anti-adsorption effect. In the in ovo model, hWJ-MSC-S reduced IBV titer by >99%. Liquid chromatography-tandem mass spectrometry (LC/MS-MS) analysis of hWJ-MSC-S revealed a significant enrichment of immunomodulatory and antiviral proteins. Collectively, our results not only uncovered the antiviral potency of hWJ-MSC-S against SARS-CoV-2 and IBV, but also described the mechanism by which hWJ-MSC-S inhibits viral infection. These findings indicate that hWJ-MSC-S could be utilized in future pre-clinical and clinical studies to develop effective therapeutic approaches against human COVID-19 and avian IB respiratory diseases.

Increasing incidence of Enterococcus-associated diseases in poultry in France over the past 15 years

Enterococci are commensal intestinal bacteria and opportunistic pathogens in humans and animals. Enterococcus-associated diseases are an emerging health issue in poultry. The aim of this retrospective study was to assess the occurrence of enterococci in poultry in France with regard to the manifested diseases and the affected avian species. Our analysis is based on veterinary laboratory data collected by the French poultry epidemiological surveillance network (RNOEA) that monitors avian diseases in France based on the voluntary participation of its veterinarian members. Since the creation of the network in 1989, 12, 177 Enterococcus cases have been reported by veterinary laboratories (Enterococcus cecorum 53.1% and Enterococcus faecalis 24.3%), with emergence starting in 2006, year in which Enterococcus represented 0.4% of all reported pathogens, and incidence growing to 12.9% in 2020. The main diseases associated with these reports were locomotor disorders 35.2% (mainly involving E. cecorum 77.9%), septicaemia 34.9% (involving E. cecorum 53.4% and E. faecalis 23.8%), and omphalitis 14.4% (mainly involving E. faecalis 59.5%). Most of these Enterococcus-associated diseases (71.5%) were reported in broilers (particularly affected by the locomotor disorders and septicaemia involving E. cecorum), accounting for 9.1% of all the diseases reported in this production sector, with an increase from 1.4% in 2006 to 17.2% in 2020. This study highlights the emergence of enterococcal diseases in poultry in France over the past 15 years and the need to maintain a surveillance system.

Avian reproductive tract diseases and surgical resolutions

Reproductive tract disease is a commonplace in avian practice, particularly among female birds. Unique anatomy and physiologyof the avian reproductive tract results in a highly productive but poorly accessible organ system. Affected hens are commonly presentedwith nonspecific lethargy, coelomic swelling and sometimes laying abnormal eggs. Reproductive diseases are less commonin male birds; however, they are well described. Although many reproductive tract diseases can be managed medically, there isa definite need for surgical intervention in some cases. Because of internal location, various disease processes and even normalphysiologic processes can dramatically alter patient presentations. For this reason, a clear understanding of avian female anatomyand male reproductive tracts is vital to diagnose and treat disorders. This manuscript focuses on recognition and treatment(emphasizing surgical management) of avian reproductive tract diseases. Because of the unique avian reproductive anatomy andfrequent need for surgical correction of disorders, the organization of the manuscript starts with descriptions of coelom and basicsurgical principles.

Identification of Newcastle Disease case on Kampung Unggul Balitbangtan (KUB) and Sentul Terseleksi (SenSi) chicken in Ungaran Research and Assessment Installation for Agricultural Technology

Newcastle Disease (ND) is a common avian disease that attacks native chickens by causing respiratory problems, thereby leading to a high mortality rate of about 60% per year and economic losses in Indonesia. This study aims to determine the prevalence of ND in Kampung Unggul Balitbangtan (KUB) and Sentul Terseleksi (SenSi) chickens which was conducted from March to June 2021, on their cages at the Ungaran Research and Assessment Installation for Agricultural Technology. The total number of 20 serum KUB and SenSi chicken samples were collected, with 25% KUb A cages, 50% KUB B cages, and 25% SenSi cages. Each chicken’s serum was analyzed for inhibition of hemagglutination (HI) to determine antibody titers against ND. The average antibody titer is expressed as a log2 value. The HI test results indicated that the KUB A cage, KUB B cage, and SenSi cage all contained positive ND antibodies. In the KUB A, KUB B, and the SenSi cages, the average ND antibody titer are 2 log 2, 0.8 log 2, and 2 log 2 respectively. In conclusion, the prevalence of ND antibodies is 100% in KUB and SenSi hens. The ND infection was not described in all chicken cages because the prior vaccine provided a limited level of protection.

A novel inactivated bivalent vaccine for chickens against emerging hepatitis-hydropericardium syndrome and infectious bursal disease

The emerging hepatitis-hydropericardium syndrome (HHS) caused by the novel genotype of fowl adenovirus 4 (FAdV-4) and the infectious bursal disease (IBD) caused by the infectious bursal disease virus (IBDV) are important avian diseases, both cause huge economic losses to the poultry industry. Therefore, it is necessary to develop an efficient and convenient FAdV-4/IBDV bivalent vaccine to prevent the spread of FAdV-4 and IBDV infections. Given that VP2 is the main structural protein and protective antigen of IBDV, we constructed a recombinant FAdV-4 expressing IBDV VP2 in our previous study. In the current study, an inactivated bivalent FAdV-4/IBDV vaccine was developed from the recombinant strain. The inactivated bivalent vaccine elicited effective and specific neutralizing antibodies against both FAdV-4 and IBDV in specific-pathogen-free chickens. Furthermore, the novel vaccine not only protected chickens from death caused by FAdV-4 and the very virulent IBDV (vvIBDV) infection, but also ameliorated target organ damage and reduced viral load. The FAdV-4-vectored vaccine developed in this study provides new options for the development of avian polyvalent inactivated vaccines and is a powerful tool for the prevention of both emerging HHS and IBD.

Coccidiosis: Recent Progress in Host Immunity and Alternatives to Antibiotic Strategies.

Coccidiosis is an avian intestinal disease caused by several distinct species of Eimeria parasites that damage the host’s intestinal system, resulting in poor nutrition absorption, reduced growth, and often death. Increasing evidence from recent studies indicates that immune-based strategies such as the use of recombinant vaccines and various dietary immunomodulating feed additives can improve host defense against intracellular parasitism and reduce intestinal damage due to inflammatory responses induced by parasites. Therefore, a comprehensive understanding of the complex interactions between the host immune system, gut microbiota, enteroendocrine system, and parasites that contribute to the outcome of coccidiosis is necessary to develop logical strategies to control coccidiosis in the post-antibiotic era. Most important for vaccine development is the need to understand the protective role of the local intestinal immune response and the identification of various effector molecules which mediate anti-coccidial activity against intracellular parasites. This review summarizes the current understanding of the host immune response to coccidiosis in poultry and discusses various non-antibiotic strategies which are being developed for coccidiosis control. A better understanding of the basic immunobiology of pertinent host–parasite interactions in avian coccidiosis will facilitate the development of effective anti-Eimeria strategies to mitigate the negative effects of coccidiosis.

Three-Dimensional Avian Hematopoietic Stem Cell Cultures as a Model for Studying Disease Pathogenesis.

Three-dimensional (3D) cell culture is attracting increasing attention today because it can mimic tissue environments and provide more realistic results than do conventional cell cultures. On the other hand, very little attention has been given to using 3D cell cultures in the field of avian cell biology. Although mimicking the bone marrow niche is a classic challenge of mammalian stem cell research, experiments have never been conducted in poultry on preparing in vitro the bone marrow niche. It is well known, however, that all diseases cause immunosuppression and target immune cells and their development. Hematopoietic stem cells (HSC) reside in the bone marrow and constitute a source for immune cells of lymphoid and myeloid origins. Disease prevention and control in poultry are facing new challenges, such as greater use of alternative breeding systems and expanding production of eggs and chicken meat in developing countries. Moreover, the COVID-19 pandemic will draw greater attention to the importance of disease management in poultry because poultry constitutes a rich source of zoonotic diseases. For these reasons, and because they will lead to a better understanding of disease pathogenesis, in vivo HSC niches for studying disease pathogenesis can be valuable tools for developing more effective disease prevention, diagnosis, and control. The main goal of this review is to summarize knowledge about avian hematopoietic cells, HSC niches, avian immunosuppressive diseases, and isolation of HSC, and the main part of the review is dedicated to using 3D cell cultures and their possible use for studying disease pathogenesis with practical examples. Therefore, this review can serve as a practical guide to support further preparation of 3D avian HSC niches to study the pathogenesis of avian diseases.

Molecular Characterization of a Novel Budgerigar Fledgling Disease Virus Strain From Budgerigars in China.

Budgerigar fledgling disease virus (BFDV) is the causative polyomavirus of budgerigar fledgling disease, an important avian immunosuppressive disease in budgerigars (Melopsittacus undulatus). In the current study, we explored the etiological role and molecular characteristics of BFDV. We identified a novel BFDV strain, designated as SC-YB19, belonging to a unique cluster with three other domestic strains (WF-GM01, SD18, and APV-P) and closely related to Polish isolates based on complete sequences. Sequence analysis showed that SC-YB19 had an 18-nucleotide (nt) deletion in the enhancer region, corresponding to the sequence position 164–181 nt, which differed significantly from all other BFDV strains. Based on sequence alignment, three unique nucleotide substitutions were found in VP4 (position 821), VP1 (position 2,383), and T-antigen (position 3,517) of SC-YB19, compared with SD18, WF-GM01, QDJM01, HBYM02, APV7, and BFDV1. Phylogenetic analyses based on complete sequences suggested that SC-YB19, along with the domestic WF-GM01, SD18, and APV-P strains, formed a single branch and were closely related to Polish, Japanese, and American isolates. These results demonstrate that BFDV genotype variations are co-circulating in China, thus providing important insight into BFDV evolution.

Northeastern Conference on Avian Diseases from 1928-2021: 93 Years of Contributions to Organized Avian Medicine.

Bacillary white diarrhea in chickens was a major disease concern for the poultry industry during the early 1900s. Drs. L. F. Rettger and W. R. Hinshaw organized a meeting in 1928 to discuss methods for controlling this disease. In this meeting, representatives of five northeastern states discussed approaches to test for the presence of the etiological agent of bacillary white diarrhea, namely, Salmonella enterica subsp. enterica serovar Pullorum. Meeting attendees decided to have a yearly meeting of the Northeastern Conference of Laboratory Workers in Bacillary White Diarrhea. The next year, the name was changed to Conference of Laboratory Workers in Pullorum Disease Eradication, which was changed to Northeastern Conference on Avian Diseases (NECAD) in 1957. Not only has NECAD been important for the control of pullorum disease but also, starting with the fifth Annual Conference in 1932, other poultry diseases became an official part of the program. As such, NECAD served for a long time as the premier organization to present new information on avian diseases. The success of NECAD was based on the work of the many committees, which are described in detail in this review. For example, the antigen committee started officially in 1929 and remained active until at least 1987. The main task of this committee was to evaluate Salmonella Pullorum strains to be used by all participants in the pullorum antibody testing programs. NECAD started as a closed organization with participants from universities and government organizations but did not allow representatives from commercial groups until 1968 when all American Association of Avian Pathologists (AAAP) members in the Northeastern United States could participate. The journal Avian Diseases started with discussions by Dr. P. P. Levine with M. S. Cover, H. L. Chute, R. F. Gentry, E. Jungherr, and H. Van Roekel about the idea that NECAD would sponsor a journal dealing specifically with avian diseases. During the first few years of Avian Diseases publication, many articles including abstracts came from the NECAD Annual Conferences. The importance of NECAD as a precursor for other regional meetings and the AAAP and as a forum for graduate students to present their research are described. Several recipients of the award for the best paper presented by a graduate student have continued to work in avian disease research. The decline in the participation of scientists in the late 1990s and early 2000s was discussed extensively in 2006 and led to a merger of the NECAD meeting with the Pennsylvania Poultry Sales and Service Conference. Due to the COVID-19 pandemic, the 92nd Annual Conference was a virtual meeting in 2020. Fortunately, the 93rd Annual Conference in 2021 was an in-person meeting held in State College, PA.

Comparison of Chicken Immune Responses to Immunization with Vaccine La Sota or ZG1999HDS Strain of Newcastle Disease Virus.

Newcastle disease (ND) is a highly contagious avian disease. Global control of ND is mainly based on vaccination of poultry; however, reported outbreaks of ND in vaccinated flocks indicate a constant need to re-evaluate the existing vaccines and a development of the new ones. In this study, 4-week-old male chickens of the layer commercial hybrid were immunized oculonasally with a commercial NDV live La Sota vaccine (LS group), a suspension of lyophilized NDV strain ZG1999HDS (ZG group), or saline (Control (K) group). Antibody response was determined by haemagglutination inhibition (HI) assay. Cell-mediated immunity (CMI) was characterized by immunophenotyping of leukocyte’s and T-lymphocyte’s subpopulations (flow cytometry). Applied NDV strains did not cause any adverse reaction in treated chickens. Both strains induced the significantly higher HI antibody response in comparison to the control group, and overall antibody titer was higher in ZG group than in LS group. CMI, manifested as a higher proliferation of B- and T-helper cells, yielded better results in the ZG groups than in the LS group. Based on the obtained results, we conclude that the strain ZG1999HDS is immunogenic and is a suitable candidate for further research and development of poultry vaccines.

Surveillance of Multi Drug Resistant Bacteria Isolated from Virally Infected Broilers

One health call to ensure human, animal and environment safety put on a major responsibility on the animal health care sector starting with identifying the circulating pathogens and its multi drug resistant (MDR) patterns. This study was conducted on total 283 diseased broilers collected from small broilers flocks in Giza and El-Kalubia province, Egypt. The clinical signs and autopsy findings were highly suggestive for: Infectious Bronchitis (IB), Avian Influenza (AI), Newcastle Disease (ND), and Chicken Infectious Anemia (CIA). Trachea, lungs, and kidney were collected during the autopsy and examined using molecular tests (PCR &amp; RT-PCR) for rapid diagnosis of the viral pathogen revealing a high incidence of IB and CIA (71.4 and 61.3%, respectively). The 165 liver and intestine samples of the virally infected broilers were subjected to bacteriological examination and all were positive for Escherichia coli (E. coli) or salmonella or both representing an extra challenge facing the infected flocks. E. coli isolates were serotyped into O125, O158 and O111 while Salmonella were serogrouped into: S. entraitidis, S. gaille and S. altona. The MDR pattern was identified by disk diffusion method using 12 different antimicrobial discs: (nalidixic acid, neomycin, trimethoprim, streptomycin, norfloxacine, sulfamethazine, chloramphenicol, tetracycline, doxycycline, oxytetracycline, gentamycin, and fosfomycine). The results showed complete resistance to sulfamethazine, nalidixic acid and oxytetracycline. High resistance to chloramphenicol, trimethoprim, tetracycline, and streptomycin, low resistance to gentamycin, and all isolates were sensitive to fosfomycine. This study revealed MDR bacterial pathogens are highly prevalent among the small poultry flocks and greatly interacts with the viral avian diseases here in Egypt.