Fatima Chegdani | PubMed Health

PubMed2025

First surveillance study of avian orthoavulavirus type 1 in wild birds in Morocco: Insights and implications for future monitoring.

BACKGROUND: Wild birds, particularly migratory species, can act as natural reservoirs and vectors of avian orthoavulavirus type 1 (AOAV-1) or Newcastle disease virus (NDV), contributing to its spread across regions and potentially threatening domestic poultry populations. AOAV-1, also known as NDV, is a major pathogen affecting avian species and poses a global threat to poultry production. It belongs to the Paramyxoviridae family and is an RNA virus encoding six key proteins, including the fusion (F) protein, which determines pathogenicity. AOAV-1 is classified into three pathotypes based on virulence: velogenic (highly pathogenic), mesogenic (moderately pathogenic), and lentogenic (mild or asymptomatic). In Morocco, AOAV-1 is endemic in poultry production systems, as evidenced by recent studies reporting a 52.1% seroprevalence and active viral RNA detection in backyard chickens in the Khemisset and Skhirat-Temara provinces; however, effective vaccination strategies have contributed to controlling the clinical signs and widespread dissemination of the virus. AIM: The main objective of this study was to investigate the presence of AOAV-1 in wild bird populations across Morocco, providing insights into possible transmission of infection affecting domestic poultry. METHODS: From November 2016 to April 2022, a total of 1984 samples were collected from 840 individual birds, encompassing 79 species, 25 families, and 12 orders. The majority of the samples belonged to Charadriiformes, Anseriformes, Pelecaniformes, and Passeriformes. Sampling was conducted at 17 wetlands and six additional locations throughout Morocco. Viral detection was performed using real-time reverse transcriptase PCR (RT-qPCR) targeting Matrix (M) and RNA polymerase (L) genes to confirm the presence of AOAV-1. RESULTS: Although the study spanned 6 years and included a large number of samples from bird orders considered primary AOAV-1 reservoirs, all samples tested negative for NDV RNA using both M and L gene targets. CONCLUSION: This study represents the first effort in Morocco to monitor wild birds for AOAV-1. The samples analyzed were initially collected for avian influenza surveillance, which shares epidemiological similarities with Newcastle's disease. However, to improve future surveillance efforts, sample collection should be optimized to target scenarios with the highest probability of virus detection.

Animals↗

PubMed2024

Mitochondrial DNA control-region and coding-region data highlight geographically structured diversity and post-domestication population dynamics in worldwide donkeys.

Donkeys (Equus asinus) have been used extensively in agriculture and transportations since their domestication, ca. 5000-7000 years ago, but the increased mechanization of the last century has largely spoiled their role as burden animals, particularly in developed countries. Consequently, donkey breeds and population sizes have been declining for decades, and the diversity contributed by autochthonous gene pools has been eroded. Here, we examined coding-region data extracted from 164 complete mitogenomes and 1392 donkey mitochondrial DNA (mtDNA) control-region sequences to (i) assess worldwide diversity, (ii) evaluate geographical patterns of variation, and (iii) provide a new nomenclature of mtDNA haplogroups. The topology of the Maximum Parsimony tree confirmed the two previously identified major clades, i.e. Clades 1 and 2, but also highlighted the occurrence of a deep-diverging lineage within Clade 2 that left a marginal trace in modern donkeys. Thanks to the identification of stable and highly diagnostic coding-region mutational motifs, the two lineages were renamed as haplogroup A and haplogroup B, respectively, to harmonize clade nomenclature with the standard currently adopted for other livestock species. Control-region diversity and population expansion metrics varied considerably between geographical areas but confirmed North-eastern Africa as the likely domestication center. The patterns of geographical distribution of variation analyzed through phylogenetic networks and AMOVA confirmed the co-occurrence of both haplogroups in all sampled populations, while differences at the regional level point to the joint effects of demography, past human migrations and trade following the spread of donkeys out of the domestication center. Despite the strong decline that donkey populations have undergone for decades in many areas of the world, the sizeable mtDNA variability we scored, and the possible identification of a new early radiating lineage further stress the need for an extensive and large-scale characterization of donkey nuclear genome diversity to identify hotspots of variation and aid the conservation of local breeds worldwide.

Animals↗