Molecular Characterization of Chicken Anaemia Virus Circulating in Commercial Poultry Flocks in Egypt during 2020

Chicken Anemia Virus (CAV) is an extremely contagious immunosuppressive disease causing high economic losses in poultry production. In the present study, tissue samples (bone marrow, thymus, and spleen) were collected from 86 different broiler chicken farms located in fourteen governorates in Egypt during 2020. They suffered from retard growth, weakness, and a drop in egg production with an observed mortality rate ranged 5-15%. A total of 26 samples were positive for CAV using PCR in six governorates in Lower Egypt with a 30% incidence rate, especially in Sharkia (78%), Ismailia (62.5%), and Alexandria (60%). The viral protein1 (VP1) gene of CAV was genetically characterized by sequencing of 10 selected viruses in six governorates. revealing that all Egyptian strains were clustered into two groups (A, B) that was distinct from vaccine strains (Del-Ros, Cux-1, and 26PA) which were clustered in group C. The seven Egyptian viruses in this study (A-Egypt-AN1-2020 to A-Egypt-AN7-2020) were clustered with the viruses from Japan, Argentina, and Malaysia in group A, and the other three viruses (A-Egypt-AN8-2020, A-Egypt-AN9-2020, A-Egypt-AN10-2020) were clustered with the viruses from Nigeria, and India in group B. The Egyptian viruses in the current study acquired new specific mutations clustering them into new subgroups (2A, 2B). By mutation analysis comparing with Del-Rose reference strains, V75I, M97L, and K139Q, E144Q were recorded in all viruses in the group A and B. All Egyptian viruses in the current study had specific new mutations at Y13N, H22N. Moreover, mutation at G74E in Egyptian viruses recorded in the current study was related to sub group 2A, I83V in three strains (A/Egypt/AN1/2020, A/Egypt/AN2/2020, A/Egypt/AN4/2020), and S140A in the hypervariable region was found in four strains (A/Egypt/AN1/2020, A/Egypt/AN2/2020, A/Egypt/AN4/2020 and A/Egypt/AN5/2020) in subgroup 2A. Furthermore, Q139 and Q144 amino acid substitutions, which are important in viral replication, were observed in all viruses. The field viruses in the study were distinct from the vaccinal strains by phylogenetic analysis and A.A. identity. In conclusion, the CAV was continuously circulating in Egypt from different genotypes. It acquired new specific mutations clustering them in a new subgroup, and it was distinct from vaccinal strains. Therefore, it is important to conduct continuous monitoring on the genetic evolution of CAV and further studies on the pathogenicity of the virus and the vaccine efficacy.

Experimental Control of a Reaction Occurring during the Interaction between Chicken Anemia Virus (CAV) and Its Corresponding Antibodies

In our ongoing investigations, we have studied a specific interaction between electromagnetic fields and matter – the so-called Electromagnetic echo effect (EMEE). It enables rapid and contactless investigations of gases, liquids and solids to be performed, since the signal generated as a result of the effect is quite sensitive to all kinds of changes occurring within the studied samples. The effect can be considered universal for all matter and provides analysis in real time. We use this phenomenon to demonstrate the practical possibility to control reactions, occurring between Chicken anemia virus (CAV) and the corresponding antibodies. This methodology can be used for simple but reliable control of similar, otherwise hard to detect, antigen-antibody reactions, in order to confirm the presence of a certain viral species. The approach offers a high level of safety, since it enables measurements to be taken remotely, thus limiting exposure to contagion. We further discuss the possibility to register the presence of SARS-nCoV-2 in an attempt to address current global pandemic.

Apoptosis Triggered by ORF3 Proteins of the Circoviridae Family

Apoptosis, a form of the programmed cell death, is an indispensable defense mechanism regulating cellular homeostasis and is triggered by multiple stimuli. Because of the regulation of apoptosis in cellular homeostasis, viral proteins with apoptotic activity are particular foci of on antitumor therapy. One representative viral protein is the open reading frame 3 (ORF3) protein, also named as apoptin in the Circoviridae chicken anemia virus (CAV), and has the ability to induce tumor-specific apoptosis. Proteins encoded by ORF3 in other circovirus species, such as porcine circovirus (PCV) and duck circovirus (DuCV), have also been reported to induce apoptosis, with subtle differences in apoptotic activity based on cell types. This article is aimed at reviewing the latest research advancements in understanding ORF3 protein-mediated apoptosis mechanisms of Circoviridae from three perspectives: subcellular localization, interactions with host proteins, and participation in multiple apoptotic signaling pathways, providing a scientific basis for circovirus pathogenesis and a reference on its potential anticancer function.

Establishment of an In Vitro Model of Persistent Chicken Anemia Virus Infection

Persistent infection of chicken anemia virus (CAV) in chickens has been suspected to result in immunosuppression and exogenous virus contamination within vaccine production. However, no direct evidence for persistent CAV infection has thus far been obtained. In this study, we aimed to establish an in vitro model of persistent CAV infection. CAV-infected MDCC-MSB1 (MSB1) cells, a Marek’s disease virus-transformed continuous cell line, were cultured in the presence of both CAV and CAV neutralizing antibody (NA). Cell viability, expression of viral antigens, viral DNA, and recovery of CAV were examined by acridine orange/propidium iodide staining, immunofluorescence measurement, real-time PCR, and viral isolation, respectively. The results indicated that CAV was maintained and possibly replicated in CAV-infected cells cultured in the presence of NA, without affecting host cell viability. It was also shown that persistently infectious CAV induced cell death again after removing NA. The persistent infection of CAV in MSB1 cells was not related to viral gene mutation. In summary, we have herein established a novel model of persistent CAV infection in MSB1 cells cultured in the presence of NA.

Clinico-Pathological and Hemato-Biochemical Assessment of Field Originated Chicken Anemia Virus in Experimentally Challenged Broiler Chicken

One hundred broiler chicks were divided into two groups A and B. The chicks in group A were control group and group B was challenged with field originated chicken infectious anemia virus (CIAV) at 7th day of age. The samples were collected on 7th, 14th, 21st, 28th and 35th day of post infection for hematological, biochemical, immunohistochemical and histopathological examination. The hematological analysis showed significantly (P Less than 0.05) low level of hemoglobin, decreased packed cell volume, leukocytopenia and thrombocytopenia in infected group as compared to control group. In immunohistochemical assay, CIAV was detected in portal zone of liver, epicardium and myocardium, lymphoid follicles of bursa of Fabricius, thymic lobules and mainly white pulp of spleen. Histopathological changes were observed in both lymphoid and non-lymphoid organs. Concerning the serum biochemical profile, hypoproteinemia, hypoalbuminemia, increased concentration of liver enzymes, creatinine and urea were observed in infected birds. Our results showed that field originated stra in is pathogenic for broilers which induce significant changes in hematology, serum biochemical profile and histopathology of lymphoid and non-lymphoid organs.