Toxoplasma gondii: diagnosis of experimental and natural infection in pigeons (Columba livia) by serological, biological and molecular techniques

Fernanda Sartori Lima De Godoi,Hilda Fátima De Jesus Pena,Solange Maria Gennari,Sandra Mayumi Nishi

doi:10.1590/s1984-29612010000400009

Fernanda Sartori Lima De Godoi, Hilda Fátima De Jesus Pena + Show 2 more

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https://doi.org/10.1590/s1984-29612010000400009

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Abstract

This study aimed to diagnose experimental and natural Toxoplasma gondii infection in pigeons (Columba livia) by serological, biological and molecular techniques. Twelve pigeons, free of infection, were inoculated with 50 sporulated oocysts of T. gondii (VEG sample) and four remained uninfected controls. Four birds (three infected and one control) were euthanized at 15, 30, 45 and 60 days post-infection (dpi), and their tissues were used to perform a bioassay in mice and nested-PCR using B1 gene as target. Blood was obtained weekly and it was tested for the presence of anti-T. gondii antibodies by the indirect fluorescent antibody test (IFAT) and modified agglutination test (MAT). Seven (58.3%) out of 12 inoculated pigeons were positive by serological techniques and titers ranged between 1:40 and 1:5120 by MAT and between 1:512 and 1:4096 by IFAT. Complete agreement was seen between the results obtained by serological techniques and nested-PCR in seven positive birds. In the bioassay in mice, five (41.7%) out of 12 pigeons inoculated were positive to T. gondii. Only one pigeon died at 23 dpi due to toxoplasmosis. A second study with free-living pigeons was performed for detection of anti-T. gondii antibodies. Birds were captured in the municipalities of São Paulo, Ibiúna and Sorocaba, São Paulo State, Southeastern Brazil. All 126 free-living birds were negative to anti-T. gondii antibodies by MAT (titer < 1:5). Bioassays were performed in mice with tissues from all captured birds and T. gondii was not isolated in any pigeon.

Highlights

Toxoplasmosis is a zoonosis of worldwide distribution caused by Toxoplasma gondii, an obligate intracellular coccidian parasite that infects most warm-blooded animals including birds, humans, domestic and wild animals (DUBEY; BEATTIE, 1988).Routine diagnosis of T. gondii infection is commonly performed by serological tests for detection of specific antibodies
Blood was obtained weekly and it was tested for the presence of anti-T. gondii antibodies by the indirect fluorescent antibody test (IFAT) and modified agglutination test (MAT)
Seven (58.3%) out of 12 inoculated pigeons were positive by serological techniques and titers ranged between 1:40 and 1:5120 by MAT and between 1:512 and 1:4096 by IFAT

Summary

Introduction

Routine diagnosis of T. gondii infection is commonly performed by serological tests for detection of specific antibodies. In chickens, T. gondii has already been isolated in serologically negative birds (DUBEY et al, 2002, 2003a, b, 2005a, 2007). Pigeons (Columba livia) are widely distributed in all continents, except Antarctica (GIBBS et al, 2001), and they were introduced in Brazil in the sixteenth century as a domestic bird. These birds are very well adapted and proliferate without control in urban centers, attaining urban pest status (SÃO PAULO, 2010)

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