Mutation Research 559 (2004) 169–176 Does toxoplasmosis cause DNA damage? An evaluation in isogenic mice under normal diet or dietary restriction D.A. Ribeiro a,∗ , P.C.M. Pereira b , J.M. Machado b , S.B. Silva c , A.W.P. Pessoa c , D.M.F. Salvadori a a Núcleo de Avaliação Toxicogenética e Cancer´ ıgena, TOXICAN, Departamento de Patologia, Faculdade de Medicina de Botucatu, UNESP, 18618-000Botucatu, SP, Brazil b Departamento de Doenças Tropicais e Diagnóstico por Imagem, Faculdade de Medicina de Botucatu, UNESP, 18618-000Botucatu, SP, Brazil c Departamento de Cl´ ınica Veterinária, Faculdade de Medicina Veterinária e Zootecnia, UNESP 18618-000, Botucatu, SP, Brazil Received 17 September 2003; received in revised form 30 December 2003; accepted 21 January 2004 Abstract Toxoplasmosis is an anthropozoonotic widespread disease, caused by the coccidian protozoan parasite Toxoplasma gondii. Since there are no data regarding the genotoxicity of the parasite in vivo, this study was designed to evaluate the genotoxic potential of the toxoplasmosis on isogenic mice with normal diet or under dietary restriction and submitted to a treatment with sulfonamide (375 g/kg per day). DNA damage was assessed in peripheral blood, liver and brain cells using the comet assay (tail moment). The results for leucocytes showed increases in the mean tail moment in mice under dietary restriction; in infected mice under normal diet; in infected, sulfonamide-treated mice under normal diet; in infected mice under dietary restriction and in infected sulfonamide-treated mice under dietary restriction. In liver and brain cells, no statistically significant difference was observed for the tail moment. These results indicated that dietary restriction and T. gondii were able to induce DNA damage in peripheral blood cells, as detected by the comet assay. © 2004 Elsevier B.V. All rights reserved. Keywords: Comet assay; Dietary restriction; Genotoxicity; Mouse; Sulfonamide; Toxoplasmosis 1. Introduction Toxoplasma gondii (T. gondii) is a coccidian pro- tozoan parasite that commonly produces subclinical infection (toxoplasmosis) or mild lymphadenopathy in adults, and severe opportunistic infections in in- fants, in utero, and in patients with AIDS [1–3]. Hu- mans may be infected by ingesting oocysts present in ∗ Corresponding author. Tel.: +55-14-388-28255; fax: +55-14-3815-2348. E-mail address: ak92@hotmail.com (D.A. Ribeiro). feces of cats [4] or in incompletely cooked lamb or pork meat [3–6]. Probably, domestic cats are the ma- jor source of contamination, since oocyst formation is higher in these animals [7]. Moreover, oocysts in sporulated forms survive for long periods under most ordinary environmental conditions, as for example in moist soil they can survive for months and even years [4]. Other disorders caused by T. gondii have been re- ported in organs, such as eyes, central nervous system, liver, etc. [8,9]. Nearly one-third of the world population has been exposed to this parasite, but the infection occurs 1383-5718/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.mrgentox.2004.01.007