Genetic characterization and distribution of the virus in chicken embryo tissues infected with Newcastle disease virus isolated from commercial and native chickens in Indonesia

Abstract

Background and Aim: Newcastle disease (ND) is a viral infectious disease that affects commercial and native chickens, resulting in economic losses to the poultry industry. This study aimed to examine the viral strains circulating in commercial and native chickens by genetic characterization and observe the distribution of Newcastle disease virus (NDV) in chicken embryonic tissue. Materials and Methods: ND was detected using a quantitative reverse transcription-polymerase chain reaction. Genetic characterization of the fusion (F) and hemagglutinin-neuraminidase (HN) genes from the eight NDVs was performed using specific primers. The sequence was compared with that of other NDVs from GenBank and analyzed using the MEGA-X software. The distribution of NDV in chicken embryos was analyzed based on lesions and the immunopositivity in immunohistochemistry staining. Results: Based on F gene characterization, velogenic NDV strains circulating in commercial and native chickens that showed varying clinical symptoms belonged to genotype VII.2. Lentogenic strains found in chickens without clinical symptoms were grouped into genotype II (unvaccinated native chickens) and genotype I (vaccinated commercial chickens). Amino acid variations in the HN gene, namely, the neutralization epitope and antigenic sites at positions 263 and 494, respectively, occurred in lentogenic strains. The NDV reaches the digestive and respiratory organs, but in lentogenic NDV does not cause significant damage, and hence embryo death does not occur. Conclusion: This study showed that velogenic and lentogenic NDV strains circulated in both commercial and native chickens with varying genotypes. The virus was distributed in almost all organs, especially digestive and respiratory. Organ damage in lentogenic infection is not as severe as in velogenic NDV. Further research is needed to observe the distribution of NDV with varying pathogenicity in chickens.

Characterization of Chicken-Derived Genotype VII Newcastle Disease Virus Isolates from Northwest China

“…The lentogenic NDV strains were distributed in almost all organs, especially the digestive and respiratory organs, in the virus-infected chicken embryo, whereas organ damage with lentogenic infection was not as severe as that with velogenic NDV (genotype VII.2). Dead embryos were observed to be hemorrhaging in almost all visceral organs after genotype VII.2 NDV infection ( Angeliya et al., 2022 ).…”

Newcastle Disease Polyclonal Antibodies as Candidate Reagents in Immunohistochemistry Diagnostic Test and Passive Immunization

“…The IHC method is used to identify proteins and other macromolecules in tissues and cells. The antibodies used to localize antigens in cells or tissues are widely used in many essential discoveries (Nakamura et al 2008;Burry 2011;Etriwati et al 2017;Angeliya et al 2022). Polyclonal antibodies can be produced quickly and at a lower cost than monoclonal antibodies (Lipman et al 2005;Putri et al 2018a;Putri et al 2022).…”

“…An important reagent used in the IHC test is the primary antibody. The primary antibody is used as a specificity control and ensures the primary antibody binds to the proper epitope on the antigen (Etriwati et al 2017;Angeliya et al 2022).…”

“…Newcastle Disease (ND) does not produce a pathognomonic sign, so often confused with other poultry diseases, such as Avian Influenza and Infectious Bronchitis. In determining the diagnosis of ND diagnosis, an immunodiagnostic test is needed, such as Immunohistochemistry (IHC), which is used as an essential tool in laboratory diagnosis (Nakamura et al 2008;Etriwati et al 2017;Angeliya et al 2022). The IHC method has been applied as a qualitative test that is effective, accurate, easy to implement, and inexpensive to detect the presence of ND antigens in tissues (Oldoni et al 2005;Wakamatsu et al 2006).…”

“…The IHC is a technique for identifying antigens based on antigen-antibody interactions (Etriwati et al 2017;Angeliya et al 2022). Antibodies in the IHC technique play a role in binding to homologous antigens present in infected tissue (Ramos-Vara and Miller 2014).…”