Description:
<jats:title>Abstract</jats:title><jats:sec>
<jats:title>Background</jats:title>
<jats:p>Toxoplasmosis is a widespread zoonosis caused by the intracellular protozoan parasite <jats:italic>Toxoplasma gondii.</jats:italic> Limited epidemiological information is available about the prevalence of <jats:italic>T. gondii</jats:italic> in sheep in Romania, and a high incidence would have implications for both the economy and public health. To our knowledge, no studies are available about the <jats:italic>T. gondii</jats:italic> strains circulating in lambs. The objective of this study was to assess the prevalence of <jats:italic>T. gondii</jats:italic> in sheep (serology), lambs (serology, bioassay, PCR) and sheep abortions (PCR) in Romania. Moreover, the study aimed to perform the genetic characterization of <jats:italic>T. gondii</jats:italic> isolates from lambs.</jats:p>
</jats:sec><jats:sec>
<jats:title>Methods</jats:title>
<jats:p>Serum samples collected from 2650 sheep (2067 adults and 583 lambs) were tested for anti-<jats:italic>T. gondii</jats:italic> antibodies (IgG) using a commercial ELISA kit. Likewise, 328 pairs of diaphragmatic muscle-serum samples were collected from lambs aged between 2 and 4 months. Lamb serum samples were analyzed using MAT for anti-<jats:italic>T. gondii</jats:italic> antibody detection. The diaphragm tissue samples from MAT-positive lambs (at a dilution ≥ 1:25) were bioassayed in mice. The <jats:italic>T. gondii</jats:italic> strains were genotyped using 15 microsatellites markers. Additionally, brain and heart samples from 76 sheep abortions were analyzed for <jats:italic>T. gondii</jats:italic> DNA by polymerase chain reaction (PCR) targeting the 529-bp repeat region (REP529).</jats:p>
</jats:sec><jats:sec>
<jats:title>Results</jats:title>
<jats:p>The results showed that more than half of the tested sheep were <jats:italic>T. gondii</jats:italic> seropositive (53.5%). The seroprevalence was significantly higher in adults (61.1%) than in lambs (26.4%). The seroprevalence of <jats:italic>T. gondii</jats:italic> infection in slaughtered lambs, by MAT, was 37.5% (123/328). There were bioassayed in mice 56 diaphragmatic tissues from 123 seropositive lambs. <jats:italic>Toxoplasma gondii</jats:italic> strains were isolated from 18 (32.1%) lambs intended for human consumption. All <jats:italic>T. gondii</jats:italic> strains were confirmed by PCR. Six strains were genotyped using 15 microsatellite markers and belonged to genotype II. <jats:italic>Toxoplasma gondii</jats:italic> DNA was detected in 11.8% (9/76) of sheep abortions.</jats:p>
</jats:sec><jats:sec>
<jats:title>Conclusions</jats:title>
<jats:p>The present study showed the presence of <jats:italic>T. gondii</jats:italic> in sheep in all the regions considered in the study. The high prevalence of <jats:italic>T. gondii</jats:italic> infection in sheep and lambs, demonstrated by serology, molecular analysis and bioassay, highlighted that there is an important risk of human infection in consuming raw or undercooked sheep/lamb meat.</jats:p>
</jats:sec><jats:sec>
<jats:title>Graphical Abstract</jats:title>
</jats:sec>