Detection, Quantification and Molecular Characterization of Fowl Adenoviruses Circulating in Ecuadorian Chicken Flocks during 2019–2021

Abstract

Fowl adenoviruses are a group of pathogens that cause large economic losses worldwide in the poultry industry, in addition to producing a wide range of diseases, such as IBH, HHS, and enteric and respiratory diseases. The objective of this study was to quantify, identify, and molecularly characterize the types of FAdV circulating in commercial poultry farms (broilers, breeders, and layers) in Ecuador from 2019 to 2021. Molecular characterization was performed by PCR, quantification by qPCR, and subsequent sequencing for each positive sample. The results indicated that the FAdV genotypes circulating in our country are FAdV-2/D2, FAdV-6/E1, FAdV-8a/E2, and FAdV-11/D3; the samples were grouped into different groups that contain sequences that were obtained from countries in Africa, Asia, and America, and that are found in birds at different ages, since early age where can cause different clinical signs, such as diarrhea, ruffled feathers and dwarfism. Therefore, these results indicate that several genotypes of the virus are circulating in commercial poultry flocks, suggesting that biosecurity measures on farms should be improved, in addition to carrying out new or improved vaccination plans.

First Molecular Detection and Characterization of Fowl Aviadenovirus Serotype 11 from Broiler Chickens in Chile

“…Despite the variety of existing serotypes, only FAdV-C serotype 4 had been reported in Chile. However, other fowl aviadenovirus serotypes, e.g., the FAdV-D serotype 11, are not unexpected in Chile since the serotype has been reported in other South American countries, like Brazil [23] and recently, Ecuador [24]. These FAdVs could have been introduced via infected day-old imported broiler breeder chicks, though confirmation would require analysis of the broiler breeders or the breeders of origin.…”

“…The disease has also been reported in Germany, France, South Africa [20], and the USA [21]. In South America, IBH cases have been reported in Peru [22], Brazil [23], and Ecuador [24]. In Chile, an outbreak of inclusion body hepatitis/hydropericardium syndrome associated with FAdV-C serotype 4 was reported in 1999 using virus neutralization tests (VNTs) and restriction enzyme analysis of a DNA fragment.…”

Evolving Horizons: Adenovirus Vectors’ Timeless Influence on Cancer, Gene Therapy and Vaccines

“…More guidance and common understanding are required to establish a standard source of ARMs across multiple generations to normalize it across fields and species. To accurately quantify rAdV originating from multiple groups and animal origins, many studies have recently been completed using dPCR, ddPCR, or UHPLC-MS/MS [187][188][189][190][191]. We need an optimized and largely accepted rAdV quantification technique which would be easier to adapt from academia to industry to make it more versatile.…”

Prevalence, genomic characteristics, and pathogenicity of fowl adenovirus 2 in Southern China

“…Our previous study found out FAdV-2 can also cause HHS in chicks in both clinical and experimental cases ( Xie et al, 2022 ). Recently, Outbreaks of FAdV-2 has been frequently reported worldwide in chicken flocks, leading to significant economic losses in the poultry industry ( Li et al, 2022 ; Niu et al, 2022 ; Santander-Parra et al, 2023 ; Wang et al, 2023 ; Zhuang et al, 2023 ). FAdV-2 and FAdV-8b have been reported in South Africa ( Joubert et al, 2014 ; Maartens et al, 2014 ), while FAdV-2, -8a, -8b, and -11 were prevalent in Europe and North America ( Schade et al, 2013 ; Marek et al, 2016 ; Niczyporuk, 2016 ; Schachner et al, 2016 ; Niczyporuk and Kozdrun, 2022 ).…”