Ovine toxoplasmosis: Indirect immunofluorescence for milk samples as a diagnostic toolby Aleksandro S. Da Silva, Alexandre A. Tonin, Giovana Camillo, Augusto Weber, Leandro S. Lopes, Chrystian J. Cazarotto, Alexandre Balzan, Anderson E. Bianchi, Lenita M. Stefani, Sonia T.A. Lopes, Fernanda F. Vogel

Small Ruminant Research


Food Animals / Animal Science and Zoology


Please cite as a diagn

ARTICLE IN PRESSG ModelRUMIN-4709; No. of Pages 4

Small Ruminant Research xxx (2014) xxx–xxx

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Augusto Weber , Leandro S. Lopes , Chrystian J. Cazarotto ,

Alexandre Balzana, Anderson E. Bianchic, Lenita M. Stefania,d,

Sonia T.A. Lopesb, Fernanda F. Vogelb a Department of Animal Science, Universidade do Estado de Santa Catarina, Chapecó, SC, Brazil b Department o c Graduate Pro d Graduate Pro a r t i c l

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E-mail add http://dx.doi.o 0921-4488/© this article in press as: Da Silva, A.S., et al., Ovine toxoplasmosis: Indirect immunofluorescence for milk samples ostic tool. Small Ruminant Res. (2014), http://dx.doi.org/10.1016/j.smallrumres.2014.03.013 f Preventive Veterinary Medicine, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil gram in Animal Science, Universidade Tecnológica Federal do Paraná, Dois Vizinhos, PR, Brazil gram in Animal Science, Universidade do Estado de Santa Catarina, Lages, SC, Brazil e i n f o ecember 2013 vised form 21 March 2014 arch 2014 e xxx ndii a b s t r a c t

Toxoplasmosis in sheep causes severe economic losses to farmers and it is a major public health problem. Consumption of ovine products, like milk, is growing worldwide and techniques that allow a snapshot on possibly infected herds are important. Indirect immunofluorescence assay (IFA) is a simple, safe, inexpensive, and sensitive test commonly used to diagnose toxoplasmosis. Tachyzoites of Toxoplasma gondii have been detected in milk of several intermediate hosts, including sheep. Thus, the aim of this study was to develop and to standardize an indirect immunofluorescence assay for milk samples (individually collected or from bulk tanks) of sheep naturally infected by T. gondii. Our experimental design was composed of 40 dairy sheep divided in 4 groups (A–D) with 10 animals each. Blood and milk samples were collected individually (40 samples). Milk samples were pooled by group and another milk sample was collected from the bulk tank. The search for anti-T. gondii in sera samples and milk was performed through IFA. We found 18 blood samples positives (45%) for T. gondii with titers ranging from 1:16 to 1:128, while only 10 (25%) milk samples were positives for toxoplasmosis, both using the IFA test. IFA test was able to detect positive samples for Toxoplasmosis either when pooled or bulk tank milk samples were used. Thus, we concluded that IFA technique can be used to quickly identify

T. gondii infected herds and it presents a good correlation among results from blood and milk samples when the assay was performed individually. © 2014 Elsevier B.V. All rights reserved. ction smosis is one of the most globally widespread sease with considerable health and economic ognized as an emerging food-borne parasitic ding author. Tel.: +55 49 3330 9432. ress: aleksandro ss@yahoo.com.br (A.S. Da Silva). disease (Dorny et al., 2009). It is caused by the obligate intracellular apicomplexan parasite protozoan Toxoplasma gondii (Weiss and Dubey, 2009). Worldwide toxoplasmosis seroprevalence in sheep ranges from 4 to 95% (Tenter et al., 2000; Dubey, 2009). This disease leads to great economic losses in sheep and goats due to embryonic death and reabsorption, fetal death and mummification, abortion, stillbirth, neonatal death, infertility, and reduced herd milk production (West, 2002; Williams et al., 2005; Buxton and rg/10.1016/j.smallrumres.2014.03.013 2014 Elsevier B.V. All rights reserved.oxoplasmosis: Indirect immunoflu s as a diagnostic tool ro S. Da Silvaa,∗, Alexandre A. Toninb, Giova b ascence for milk amillob, a

Please cite osis: Indirect immunofluorescence for milk samples as a diagn 0.1016/j.smallrumres.2014.03.013

ARTICLE IN PRESSG ModelRUMIN-4709; No. of Pages 4 2 A.S. Da Silva et al. / Small Ruminant Research xxx (2014) xxx–xxx

Lesson, 2007). The Brazilian sheep herd is estimated around 17.38 million heads and the main states with sheep production are in the South and Northeast regions, representing 28.1% and 56.7% of the total population, respectively (IBGE, 2012).

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Tenter, 200 also been hosts, inclu

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Therefore, standardize samples of 2. Materials 2.1. Animals

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T. gondii. 2.2. Sampling

Blood (n = for serological sterile test tub obtain milk se was obtained the bulk tank

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The search and milk serum tachyzoites of

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Table 1

Indirect immunofluorescence assay (IFA) in the blood (serum) and milk of sheep for Toxoplasma gondii: standardization of the IFA test.

Sheep samples – indirect immunofluorescence assay (IFA) for antibodies a ps 10) positive ve resul es positi n milk, w ered po onsider tatistical analysis sults were subjected to nonparametric test (chi-square) for comn between samples in order to validate the technique for IFA for milk. sults e results of IFA for T. gondii in sera and milk samples own in Table 1. From the 40 blood samples analyzed, ere serologically positives for T. gondii with titers ranfrom 1:16 to 1:128. However, only 10 out 40 milk les were positives for toxoplasmosis. Animals with tive results in the blood were also negative when milk les were tested. Therefore, in this study we observed