Trichomonas Infection in a Community of Free-Ranging Domestic and Wild Columbiformes and Bonelli's Eagle (Aquila fasciata).

Nuno Santos,Kevin Morris Tyler,Ana Martinez Fernández,António Monteiro,Nuno Martins,Javier Garcia,Pedro J Esteves,Jorge Amaral,José Jambas,Tereza Almeida,Joana Abrantes

doi:10.3389/fvets.2019.00148

Abstract

Trichomonas gallinae is a pathogen of conservation relevance, whose main maintenance hosts are Columbiformes, but spillover to avian predators has been described. The goal of this study was to characterize the epidemiology of Trichomonas spp. in a community of free-ranging domestic and wild Columbiformes and an endangered predator, Bonelli's eagle Aquila fasciata. We surveyed 253 live-captured Rock doves, 16 nestling Bonelli's eagles and 41 hunted Columbiformes. Oro-esophageal swabs were incubated in culture media and Trichomonas spp. isolated from Bonelli's eagle (6.3%, CI95 1.1-28.3), Turtle dove Streptopelia turtur (56.3%, CI95 39.3–71.8), Wood pigeon Columba palumbus (83.3%, CI95 43.7–97.0) and Rock dove Columba livia (68.4%, CI95 62.4–73.8). Infected Rock doves showed significantly poorer body condition than uninfected ones (p = 0.022). From a subset of 32 isolates, 18S and ITS1/5.8S/ITS2 rRNA genes were sequenced and Maximum-Likelihood trees inferred. Four ribotypes of Trichomonas spp. were identified. In this study area Trichomonas spp. seem to persist in a multi-host system involving several species of Columbiformes. Conservation actions aimed at increasing the availability of trophic resources for Bonelli's eagles through Rock dove restocking should consider the risk of pathogen transmission and of introduction of alien strains.

Highlights

Trichomonosis is an avian disease of conservation relevance, caused by infection with Trichomonas gallinae [1,2,3]
Trichomonas gallinae ribotype 18S-VI, ITS-IV/B (n = 23) was distributed in Traditional pigeon lofts (TPL) throughout the study area, while T. gallinae ribotype 18S-IV, ITS-I/D (n = 3) was detected in 2 TPL recently restocked with Rock doves acquired from a mixed-species avian collection
This study reports the epidemiology of Trichomonas spp. infection in the community of maintenance hosts for this pathogen and apparent spillover to an endangered avian predator

Summary

Introduction

Trichomonosis is an avian disease of conservation relevance, caused by infection with Trichomonas gallinae [1,2,3]. Trichomonosis can be present as subclinical to subacute, depending on the host species, immune status and the pathogenicity of the strain [1, 2, 4,5,6,7,8]. Trichomonas gallinae is an important pathogen of Columbiformes, Falconiformes, and Passeriformes [3] It has been implicated in the decline of Band-tailed pigeons (Patagioenas fasciata) in western USA [2] and a highly pathogenic strain has recently emerged in North-Western Europe, causing population declines of finch species [3, 7, 12]. The Turtle dove (Streptopelia turtur) was shown to be heavily infected by Trichomonas gallinae [8, 15]. Raptors are considered spillover hosts, acquiring infection from infected prey [3, 17]

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