Pathological and molecular findings of avian avulavirus type 1 outbreak in pigeons (Columba livia) of southern Brazil

Abstract

The Newcastle disease, caused by avian avulavirus type 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Several outbreaks have been reported over the last 30 years in Columbiformes in different parts of the world, caused by a adapted variant strain of AAvV-1, called pigeon paramyxovirus type 1 (PPMV-1). A high mortality associated with an outbreak was analyzed in free-living pigeons (Columba livia) in a public square in Porto Alegre in Southern Brazil. A total of 24 pigeons moribund or freshly dead, within five weeks interval were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), and RT-PCR followed by sequencing of the amplification products analysis. They presented neurological signs, non-suppurative encephalitis and encephalomyelitis, and mononuclear inflammatory infiltrate in different organs. Immunohistochemical analysis in nine pigeons tissue showed that anti-Newcastle was expressed in brain, kidney, liver and pancreas. The RT-PCR test for the M protein of Newcastle disease virus was positive in six pigeons. The differential diagnosis of Influenza, West Nile, Mycoplasma gallisepticum and Mycoplasma synoviae in all pigeons presented negative results. The sequence of amino acids in the cleavage site region of the F protein was 112RRQKRF117 classifying the strain as virulent. The phylogenetic analysis classified this virus strain into Class II and VI genotype.

Detection of Avian Orthoavulavirus-1 genotypes VI.2.1 and VII.1.1 with neuro-viscerotropic tropism in some backyard pigeons (Columbidae) in Eastern Saudi Arabia

“…Natural infection of pigeons and doves with viruses of genotype VI.2.1 (nucleotide identity of >95%) was reported to induce Additionally, comparable nervous signs and mortality rates were observed on birds from which similar VI.2.1 sequences (> 95%) were recovered ( 56 , 63 , 64 ). Likewise, similar nervous signs were reported in pigeons infected with less similar isolates of genotype VI.2.1 ( 54 , 65 ) and genotype VI.2.2.2.2 ( 66 ). Inconsistent clinical signs were reported after the experimental infection of pigeons with viruses of genotype VI.…”

“…RT-PCR, followed by sequencing of the F gene, has been widely used to detect virulence and to connect AOAVs recovered from different outbreaks ( 65 ). The present study's genotyping RT-PCR failed to detect AOAV1 in samples from 2 out of the eight pigeon flocks.…”

Identification of a Virulent Newcastle Disease Virus Strain Isolated from Pigeons (Columbia livia) in Northeastern Brazil Using Next-Generation Genome Sequencing

“…Our phylogenetic analysis, using 62 complete NDV genome sequences available at GenBank, revealed that the NDV/pigeon/PE-Brazil/MP003/2018 belongs to genotype VI.2.1.2. This virus was closely related to other viruses isolated from pigeons in Argentina, Rio Grande do Sul (southern Brazil) and São Paulo in 2019 (southeastern Brazil) [ 32 , 33 , 35 ]. Since the genotype VI of NDV is frequently found in pigeons, this strain is commonly named Pigeon Paramyxovirus 1 (PPMV-1) [ 27 ].…”

“…The pigeons in this study presented neurological signs and lesions commonly observed in other Columbiformes infected by NDV [ 32 , 33 , 34 , 35 ]. The gross findings were nonspecific, which is consistent with previous reports from the literature.…”

“…However, in Brazil NDV outbreaks in free-living pigeons were registered in different periods and regions of the country. The first NDV outbreak, identified in an urban area, occurred in feral pigeons from a public square in Porto Alegre, Southern Brazil in 2014 [ 35 ]. The phylogenetic analysis of this first report classified the virus as an NDV Class II genotype VI.…”