In the summer of 2019, a 55-week-old broiler breeder flock in north Georgia exhibited an unusual case of swollen head syndrome. The patient's presenting concern was the noticeable swelling of the head, coupled with elevated mortality rates. Necropsy findings on the affected farm birds predominantly displayed symptoms of bacterial blood poisoning, with a few large scab lesions situated near the vent area. Despite the presence of multiple bacterial organisms in the cultures, Erysipelothrix rhusiopathiae, isolated from the diseased liver, lungs, sinuses, and one swollen wattle of a bird from the affected house, emerged as the main organism of interest. Through histopathologic analysis, gram-positive rod-shaped bacteria were observed in the spleen and liver, indicative of bacterial septicemia, a diagnosis further validated by the application of the Brown & Hopps Gram stain. These organisms displayed characteristics strongly indicative of E. rhusiopathiae; Infection of broiler breeder chickens with E. rhusiopathiae is a rare event and predominantly found in the context of turkey or swine production

The poultry industry can experience substantial financial strain due to sudden drops in commercial egg production, and precise identification of the cause often depends on the collaboration of producers, veterinarians, and pathologists. A significant drop in daily egg production, from 1700 to 1000 eggs, was observed in a 35-week-old commercial Pekin breeder duck flock located in Indiana during September 2019. This represented a substantial 41% decrease in output. In September 2021, three Pekin breeder duck flocks, aged 32, 58, and 62 weeks, respectively, all sourced from the same company, experienced a comparable decline in egg production. Simultaneously, there was a slight increase in weekly mortality, ranging from 10% to 25%. Birds from affected flocks were submitted for postmortem examination at Michigan State University's Veterinary Diagnostic Laboratory in 2019 and 2021. FDA-approved Drug Library Flaccid, shrunken, or atrophied ova (all hens), along with pododermatitis, airsacculitis, hepatomegaly, splenomegaly, ascites, and left ventricular pallor, were among the common gross examination findings. Upon histopathologic analysis of the cerebrum, cerebellum, and brainstem, mild lymphocytic perivascular cuffing, vasculitis, and gliosis were observed, suggesting the presence of viral encephalitis. In the heart's core, there was a mild multifocal pattern of cardiomyocyte necrosis, along with mineralization and infiltration by lymphocytes and macrophages. A PCR test was performed to identify the presence of Newcastle disease virus, avian influenza virus, eastern equine encephalitis virus, and West Nile virus (WNV). WNV was detected in both brain and heart tissue via PCR, and immunohistochemical staining indicated its presence in the cerebellum. The first report to demonstrate a connection between WNV infection and a decline in egg production in waterfowl, which act as significant reservoirs for this virus, and consequently, are typically asymptomatic.

The aim of this research was to pinpoint the diversity of Salmonella serotypes circulating amongst poultry flocks in northern India. Scrutiny of 101 poultry droppings originating from 30 farms in the Jammu and Kashmir union territory was undertaken. Nineteen Salmonella isolates were obtained, comprising four serotypes: Salmonella enterica enterica serotype Kentucky (n=3), Salmonella enterica enterica serotype Infantis (n=5), Salmonella enterica enterica serotype Agona (n=4), and Salmonella enterica enterica serotype Typhimurium (n=7). The study has shown the presence of Salmonella serotypes, which are infrequently recorded in Indian reports. The endemic human nontyphoidal salmonellosis cases in this region are often linked to isolated serotypes, according to reports. Further study is necessary to evaluate if this observation suggests a modification in the serotype pattern of poultry in the specified region. Despite this, the research definitively points to the threat of foodborne salmonellosis, linked to the consumption of tainted poultry and poultry products in the area.

The U.S. Department of Agriculture's Avian Disease and Oncology Laboratory, in the diagnosis and subtyping of field isolates associated with avian leukosis virus (ALV) outbreaks, currently depends on live birds of particular genetic backgrounds for generating chicken-embryo fibroblasts. To avoid the need for living animals for this task, we are now developing cell lines that can replicate the same result by eliminating the entry receptors used by ALV strains. FDA-approved Drug Library Within the DF-1 fibroblast cell line, CRISPR-Cas9 was utilized to disrupt the tva gene, responsible for the receptor's function in facilitating ALV-A viral entry. Seven DF-1 clones were finally found to exhibit biallelic and homozygous indels at the Cas9 target site, within exon 2 of the tva gene. In vitro testing of five clones harboring frameshift mutations within the Tva protein revealed their inability to facilitate ALV-A replication. This result serves as definitive proof that modified cell lines can form part of a battery of tests for determining ALV subtypes in isolate characterization, thus replacing the requirement for live birds.

Despite innate immunity being critical in dictating the result of avian viral infections, the precise functions of the individual components within the avian innate immune system remain poorly defined. The current study investigated the possible effects of avian toll-like receptor 3 (TLR3) and melanoma differentiation-associated gene 5 (MDA5), which are activated by double-stranded RNA (dsRNA), on the induction of the interferon pathway and avian orthoavulavirus 1 (AOAV-1) replication in chicken-origin DF-1 fibroblast cells. To create DF-1 cells lacking TLR3 and MDA5, we used an avian-specific CRISPR/Cas9 system, subsequently stimulating them with polyinosinic-polycytidylic acid (poly(IC)), a synthetic dsRNA ligand, or infecting them with AOAV-1 (formerly Newcastle disease virus). Poly(IC) treatment in cell culture media prompted a substantial upregulation of interferon (IFN), IFN, and Mx1 gene expression in wild-type (WT) DF-1 cells, but this effect was entirely absent in TLR3-MDA5 double knockout cells. Intriguingly, the application of poly(IC) elicited a rapid cellular disintegration in WT and MDA5 knockout cells, but not in TLR3 knockout or the combined TLR3/MDA5 knockout cells, thereby directly correlating poly(IC)-induced cell deterioration with TLR3-mediated host defense mechanisms. The double knockout cells demonstrated a considerably greater capacity to support the replication of AOAV-1 virus, contrasted with the WT cells. An absence of any link was found between the extent of viral replication and the type I interferon response. Our research indicates that the host's and pathogen's innate immune responses are specific, and a deeper examination is necessary to understand how dsRNA receptor-mediated immune processes influence viral replication and disease development in birds.

A syndrome evocative of liver disease, characterized by uneven occurrences, has been an informal subject of reports by poultry producers in Costa Rica for more than two decades. However, the infectious agent causing this syndrome, despite many efforts, remained unknown. As a result of the present understanding regarding spotty liver disease diagnosis, we appealed to veterinarians and poultry farmers to furnish samples for analysis at the diagnostic laboratories of the Veterinary Medicine School, Universidad Nacional, to pinpoint the infectious agent causing this syndrome. Aseptic collection of gallbladders and livers from poultry producers and veterinarians was mandated, with specimens needing to be sent for pathology examination and bacterial culture tests within 24 hours. Standard histopathologic studies were conducted on the samples, which were also cultured under aerobic, anaerobic, and microaerobic conditions. Biochemical and PCR analyses were used for isolating and determining the identity of the Campylobacter-like colonies. In Costa Rica, we are reporting, for the first time, the isolation, biochemical characterization, and molecular confirmation of Campylobacter hepaticus in laying hens and broiler breeders displaying spotty liver disease.

The emerging disease Clostridial dermatitis (CD), impacting turkeys economically, is a consequence of Clostridium septicum and Clostridium perfringens infections, and presents with both sudden mortality and necrotic dermatitis. Poorly understood immune responses are characteristic of CD-affected commercial turkeys. During a recent outbreak affecting commercial turkeys with CD, C. septicum was isolated, and samples of tissues (skin, muscle, and spleen) from affected birds, along with controls from healthy birds, were collected and analyzed for immune gene expression in the present study. A substantial increase in IL-1, IL-6, IFN, and iNOS transcript levels was observed in the skin, muscle, and spleen tissues of turkeys affected by CD, compared to the unaffected control group. In the skin and spleen tissues of affected turkeys, there was a substantial elevation in the expression of the toll-like receptor (TLR21) gene, implying a possible involvement of this receptor in the immune recognition process. FDA-approved Drug Library The expression of the IL-4 and IL-13 genes was demonstrably elevated in the spleen and muscle tissue of the affected birds. Further serological testing on additional birds from the afflicted and healthy farms showed that turkeys experiencing CD exhibited significantly elevated serum levels of IgM and IgY antibodies. C. septicum treatment of MQ-NCSU macrophages in a laboratory setting led to a significant increase in the transcriptional expression of the interleukin-1 and interferon genes, but a decrease in the expression of the interleukin-10 gene. Cellular activation was also observed in C. septicum-stimulated macrophages, characterized by a substantial elevation in MHC-II protein surface expression and nitric oxide production. Our collective findings indicate that CD-affected turkeys exhibit robust inflammatory responses coupled with an IL4/IL-13 cytokine-mediated response, potentially supporting antibody-mediated immunity.