Journal of Poultry Sciences and Avian Diseases
Volume:1 Issue: 1, Winter 2023

This study describes the development of a cross-protective vaccine candidate against avian influenza virus, which was designed using M2e, a highly preserved antigen. The consensus sequence of M2e was obtained using 31 sequences of avian influenza virus subtypes (H5N8, H5N1, H9N2, and H7N9) isolated from seven avian species in five Asian countries. An adjuvant, a partial sequence of flagellin, was also considered. Two chimeric antigens were designed and virtually cloned and expressed using the PYD1 vector and EBY100 yeast strain. Molecular dynamic simulations were used to assess the stability and conformational features of these antigens. The likelihood of detection by a specific monoclonal antibody, MAb148, was estimated for the designed peptides using docking studies. The second chimeric antigen was more compact and stable than the first design, but it was less detectable by MAb148. In the first design, two of the four desired epitopes ("SLLTEVETP") were exposed, while only a partial sequence of this epitope was detectable in the second design. In contrast to the second chimeric antigen, electrostatic, and binding energies related to the interaction of the first antigen and MAb148 were significantly closer to the positive control. This suggests that epitopes of the first chimeric antigen could be correctly located in the specific paratope of MAb148. In conclusion, the first chimeric antigen exhibits favorable conformational features and epitope-paratope interactions, highlighting its potential as a promising cross-protective vaccine candidate against a range of avian influenza virus subtypes.

Accurate estimation of genetic parameters is essential for setting selection plans in breeding programs. Over the past years, various studies reported the genetic parameters for different growth, reproduction, and egg quality traits in Iranian native fowls. These assessments were obtained using a variety of methods and from studies of different populations of native fowls, leading to significant variation in genetic parameter estimates. This study aimed to perform a meta-analysis based on a random-effects model to overcome the diversity of reported genetic parameters for economically important traits of Iranian native fowls. To summarize these results, a data set of information related to different growth, reproduction, and egg quality traits including 68 estimates of the proportion of maternal environmental variance to phenotypic variance (c2) and 38 genetic correlation estimates between direct and maternal genetic effects from articles published between 2007 and 2019 were used. Mean estimate of the proportion of maternal environmental variance to phenotypic variance for the studied traits showed that the highest estimate was related to body weight at hatch (0.273) and the lowest was for egg weight at the first day of laying (0.021). Estimation of proportion of maternal environmental variance to phenotypic variance was not significant for EN (P>0.05), but for other traits were significant (P<0.05). The genetic parameter estimates reported in this meta-analysis study are exploitable in breeding schemes when reliable estimates are not accessible for economically important traits in Iranian native fowls.

Escherichia coli (E. coli) is a very important indicator bacteria that could be used for tracking the evolution of antibiotic resistance in both humans and animals. Shiga toxin-producing E. coli (STEC) strains are responsible for the worldwide development of human intestinal disease and potentially fatal hemorrhagic colitis or hemolytic uremic syndrome which could be transferred to humans from companion animals including pet birds.A total of 200 fecal samples were collected from birds with different situations of health status, age, and sex which have been referred to the University of Tehran’s Veterinary Hospital. 26 isolates of E. coli (13%) were found from different species of birds. 9 Attaching-effacing (AEEC) isolates (34.6%) were found in this study and all of them (9 out of 9 isolates; 100%) were STEC isolates. Phylogroup analysis revealed that 4 isolates belonged to B2 and 3 isolates belonged to D phylogroup, also 2 of the isolates were un-typable. The results of the disk diffusion method showed that 7 out of 9 STEC isolates (77.7%) were considered to be multi-drug resistance (MDR). 9 out of 9 (100%) isolates were resistant to penicillin and erythromycin, and sensitive to fosfomycin and lincospectin. In B2 phylogroup, almost all the isolates were sensitive to fluoroquinolones (96.9% sensitive). In the D phylogroup, the results were different, and the isolates were 87.5% resistant or they were developing resistance against fluoroquinolones.The results of this study revealed that different species of birds which are being kept as common pets in Iran, can be affected with STEC strains and also, they could be identified as multi-drug resistant E. coli, which doubles the importance of these findings, especially for public health.

The African grey parrot (Psittacus erithacus) is among the world's most well-known seed-eating cage birds. A grain-eating diet has been reported to cause liver lipidosis in parrots. Fatty liver syndrome occurs when the liver cannot metabolize and re-secrete processed fatty acids due to excessive dietary fatty acids or lipolysis. The present study involves a 42-year-old African grey parrot with extensive feather pecking in the neck, legs, and chest areas, red color changes in the feathers on the legs, and lethargy. The patient's medical history includes the consumption of sugar, chocolate, and whole grains, which is the main reason for metabolic disorders. A comprehensive evaluation of serum biochemistry, total protein levels, aspartate aminotransferase (AST), creatine kinase (CK), triglycerides, and uric acid was conducted on the first visit. Following two weeks of treatment, the bird was again referred to the clinic for clinical pathological evaluation and diagnostic imaging. Different liver medicines, such as herbal antioxidants, vitamins, and amino acid supplements, are prescribed during the treatment process. In addition, the bird's diet was modified. Following the diet and treatment, the blood parameters reached normal limits. The echogenicity of liver tissue was close to normal after the initial observation of feathers regrowing in some areas, as well as blood sample evaluation. A paraclinical test was taken on the bird again after two months of treatment to ensure the disease did not recur. Diligent care, nutritional support, veterinary monitoring, and appropriate medications can improve hepatic lipidosis, but permanent damage may occur. Therefore, it is very critical to quickly diagnose and prevent the recurrence of the illness

Marek's disease (MD) is a significant concern in the poultry industry, causing neoplastic disease and substantial economic losses. MDV-1, MDV-2, and MDV-3 are the three serotypes of the herpesvirus that cause MD, each with unique traits and interactions with the host. Vaccination is the primary preventive measure, but some vaccinated flocks still experience losses, often due to suboptimal vaccine dosages. Accurate quantification of the virus is crucial for understanding its dynamics, evaluating vaccine efficacy, and ensuring the health and productivity of poultry populations. Virus quantification methods fall into two main categories: infectivity assays and chemical/physical assays. Infectivity assays detect active, infectious virions, such as plaque, focus formation, and endpoint dilution. Chemical/physical assays, including the hemagglutination assay, transmission electron microscopy, flow cytometry, and qPCR, target specific components of the virion. However, these methods cannot distinguish between infectious and inactivated virions, potentially leading to overestimating viable viral populations. Marek's disease viruses (MDVs) can be quantified using in vitro plaque assays in susceptible cell cultures. The viral plaque assay determines the number of plaque-forming units (pfu) in a virus sample. Titration procedures for vaccine strains are similar to those for pathogenic variants. It is crucial to assess the dose of reconstituted MD vaccine (in PFU per chicken) to identify potential vaccine inefficacies and prevent outbreaks in the field. Accurate virus quantification is pivotal in understanding viral kinetics, optimizing therapeutic interventions, evaluating vaccine effectiveness, and preventing Marek's disease outbreaks in poultry.

The goal of poultry industry worldwide is the production of safe food products, via efficient and goal-oriented health care to prevent the development of disease conditions in poultry. However, a several number of poultry diseases can negatively affects the breeding values and have the potential to be zoonotic and transmit the infections to humans such as campylobacteriosis. C. jejuni is highly prevalent in commercial poultry farms and act as major reservoirs of the infection. Horizontal transmission from the environment is considered to be the primary source of bacterial foodborne worldwide. The high prevalence of Campylobacter spp. in poultry meat is a result of several contamination and cross-contamination sources in the entire production chain. Recent investigations demonstrated that various stages of food processing in slaughterhouse and consumption of raw or undercooked poultry meat is considered the significant risk factor for human campylobacteriosis worldwide. Furthermore, survival factors such as biofilm formation and antimicrobial resistance, enable its persistence during food processing. On the other hand, the increase of multiple and multidrug-resistant Campylobacter worldwide is not only related to the over-consumption of antibiotics in human medicine, but also in poultry production chain as growth promotors and/or to treat and prevent bacterial infections.  Antibiotic resistant Campylobacter presents an obvious and impending challenge to One Health. In the future, the consumer expectations for high standards quality of poultry products will strongly influence the production methods. This means that farmers, stockholders’, veterinarians, and all other partners involved in the production chain, will have to share more responsibilities and the cooperation should be intensified. This review represents an updated overview of the global epidemiology, the correlation of official control, the disease associated with food handler and the importance of food safety with respect to Campylobacteriosis.