Research of Viral Agent in Free-living Pigeon Feces (Columba livia) in the City of São Paulo, SP, Brazil, for Transmission Electron Microscopy

Abstract

SUMMARY:The pigeon feces are vehicle of diseases both for humans and other animal species. In these birds, the most important viral diseases of the digestive tract are transmitted by the paramyxovirus, adenovirus and coronavirus. Avian paramyxoviruses have been isolated from a variety of species of free living and domestic birds worldwide, with several symptoms and clinical signs and economic losses. Paramyxoviruses belong to the Paramyxoviridae family and Avulovirus genus that includes nine serotypes (APMV 1 to 9). Avian adenoviruses belong to the Adenoviridae family and Aviadenovirus genus. In pigeons, cause classical adenovirosis and necrotizing hepatitis. The respiratory and enteric tracts are common targets of coronavirus. They belong to the Coronaviridae family and to 3a and 3c groups. In this study, we described the presence of viral agents in free-living pigeon feces (Columba livia) from the city of São Paulo, Brazil. The feces were processed by negative staining technique (rapid preparation) for transmission electron microscopy. In this technique paramyxoviruses particles, pleomorphic, roughly spherical or filamentous, measuring 100 to 500 nm of diameter containing an envelope covered by spikes, with characteristic helical herring-bone-like nucleocapsid, measuring 15 to 20 nm in diameter, were visualized in 45 (79%) out of 57 feces samples. In 2 (3.5%) samples, paramyxovirus and adenovirus particles were simultaneously visualized. Adenovirus particles were isometric, spherical, characterized as "complete "or" empty ", measuring between 70 and 90 nm in diameter. Paramyxovirus and coronavirus particles were detected in 3 (5.2%) samples. Coronaviruses were pleomorphic with a diameter of 75-160 nm containing a solar corona-shaped envelope, with projections of approximately 20 nm of diameter. Seven (12.3%) samples were negative for viral particles.

Avian Paramyxoviruses: Detection by Transmission Electron Microscopy Techniques

“…Several authors using the same technique, described the presence of particles with morphological characteristics similar in other avian species, as budgerigar (Nerome et al), dove (Alexander et al, 1981;Catroxo et al, 2011), ringedteal (Gough & Alexander), parrot and parakeet (Steffens, 1998, Grund et al), yacinth macaw, rusty collared seedeater, red cowled cardinal, curl crested and peach fronted parakeet (Catroxo et al, 2000), duck (Chang et al, 2001), cockatiel (Clavijo et al), goose (Jinding et al, 2005), gouldian finch (Zhang et al), owl (Catroxo et al, 2010) and penguin (Miller et al; Fornells et al).…”

Necrotizing Hepatitis in a Domestic Pigeon (Columba livia)

“…The structure, size, and lattice formation by these viral particles support the diagnosis of an adenoviral infection. 1,7,10,11 Diagnosis Based on the histologic lesions observed by light microscopy and further characterization of the intranuclear inclusion bodies by TEM, the diagnosis was necrotizing hepatitis with intranuclear adenoviral inclusion bodies.…”

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

“…These panzootic strains belong to genotype VI, which presents 9 subgenotypes (Dimitrov et al 2016), and has been previously described in high mortality outbreaks worldwide in different species of birds (Alexander et al 1985(Alexander et al , 1997. Pigeons must be considered seriously as a potential source of NDV infection and disease for commercial poultry flocks (Kommers et al 2002), and may be subclinically infected, spreading the virus for a considerable period of time without clinical signs (Carrasco et al 2008, Catroxo et al 2011. These may consist of apathy, anorexia, weight loss, prostration, diarrhea, polyuria, conjunctivitis, periocular edema, ruffled feathers, sneezing, dyspnea, incoordination, lack of balance, tremors, dehydration, proventricular dilatation, crop emptying problems, leukopenia and death.…”