Toxoplasma gondii in milk of naturally infected dairy ewes on west mesoregion of Santa Catarina state, Brazil

R.A. Ossani,L.C. Miletti,M. Federle,A.B. Moura,A.A. Sartor,H.A.T. Borges,A.P. Souza

doi:10.1590/1678-4162-9177

Abstract

ABSTRACT This study aimed to detect Toxoplasma gondii in the milk of dairy sheep in the Western mesorregion of state of Santa Catarina by bioassay (22 milk samples from eight ewes seropositive; IFA ≥256) and PCR [for the detection of agent in the brains of mice inoculated on bioassay and directly from milk (108 samples from 42 seropositive ewes (IFA, ≥64) in different lactation periods)]. T. gondii DNA was detected in mice brains inoculated with milk from eight sheep (a sample of the 45th day of lactation and seven in the collection of 90th day) and directly from the milk in samples of the second collection (90 days) in five animals. Taking into account both assays, from a total of 42 ewes in lactation and seropositive for T. gondii, 30.95% (13/42) of the animals presented evidences of T. gondii presence in milk. Positive PCR samples were sequenced and the results confirmed ≥97% identity with the membrane antigen P22 gene of T. gondii. The results showed that T. gondii is present in the milk of sheep, representing a possible source of infection to humans through the consumption of milk "in natura" and/or derivatives, besides the possibility of lactogenic transmission to lambs.

Highlights

Toxoplasma gondii is a protozoan that can infect warm-blooded animals including humans
Most cases of human toxoplasmosis are attributed to the consumption of raw meat or food and water infected with oocysts
Considering the results of both techniques, for 42 lactating ewes and positive for T. gondii, the parasite DNA was detected in milk of 30.95% (13/42) of the animals and in 12.04% (13/108) of the samples

Summary

Introduction

Toxoplasma gondii is a protozoan that can infect warm-blooded animals including humans. It is highly prevalent in many areas of the world, and important in human medicine and veterinary (Tenter et al, 2000). In Brazil, studies have reported wide distribution of sheep toxoplasmosis and occurrence of anti-T. gondii antibodies ranging between 7.7% and 52% (Silva and Langoni, 2001; Lopes et al 2010). Skinner et al (1990) emphasize that the consumption of contaminated milk can cause serious clinical disorders in immunocompromised children and pregnant women and Tenter et al (2000) reported seroconversion to T. gondii in children taking the goat milk regularly. The presence of T. gondii tachyzoites has been reported in the milk of sheep, goats, cattle and mice (Chiari and Neves, 1984; Vitor et al, 1991; Remington et al, 2004, Ragozo et al, 2009; Camossi et al, 2011)

Objectives

Methods

Results