title: Investigation of infectivity of neonates and adults from different rat strains to Toxoplasma gondii Prugniaud shows both variation which correlates with iNOS and Arginase-1 activity and increased susceptibility of neonates to infection.
abstract: Mouse models differ considerably from humans with regard to clinical symptoms of toxoplasmosis caused by Toxoplasma gondii and, by comparison, the rat model is more representative of this disease in humans. In the present study, we found that different strains of adult and newborn rats (Lewis, Wistar, Sprague Dawley, Brown Norway and Fischer 344) exhibited remarkable variation in the number of brain cysts following inoculation with the T.gondii Prugniaud strain. In adult rats, large numbers of cysts (1231 ± 165.6) were observed in Fischer 344, but none in the other four. This situation was different in newborn rats aged from 5 to 20 days old. All Fischer 344 and Brown Norway newborns were cyst-positive while cyst-positive infection in Sprague Dawley neonates ranged from 54.5% to 60% depending on their age at infection. In Wistar and Lewis rat neonates, however, cyst-positivity rates of 0-42.9% and 0-25% were found respectively. To investigate whether rat strain differences in infectivity could be related to inherent strain and genetic differences in the host immune response, we correlated our data with previously reported strain differences in iNOS/Arginase ratio in adult rats and found them to be linked. These results show that interactions between host genetic background and age of rat influence T.gondii infection.
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Jiang-Mei
authors.initials: JM
authors.lastname: Gao
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Yi
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Ming-Shui
authors.initials: MS
authors.lastname: Wu
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Geng
authors.affiliation: The Anhui Provincial Laboratory of Pathogen Biology, Anhui Medical University, Hefei 230032, China.
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Shen
authors.affiliation: Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Fang-Li
authors.initials: FL
authors.lastname: Lu
authors.affiliation: Ecosystems and Environment Research Centre and Biomedical Research Centre, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK.
authors.forename: Geoff
authors.initials: G
authors.lastname: Hide
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address: laidehua@mail.sysu.edu.cn.
authors.forename: De-Hua
authors.initials: DH
authors.lastname: Lai
authors.affiliation: Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Disease Control of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510275, China; Ecosystems and Environment Research Centre and Biomedical Research Centre, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK. Electronic address: lsslzr@mail.sysu.edu.cn.
authors.forename: Zhao-Rong
authors.initials: ZR
authors.lastname: Lun
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001119:Arginase / Q000378:metabolism*; D001921:Brain / Q000469:parasitology; D016009:Chi-Square Distribution; D004195:Disease Models, Animal; D060467:Disease Resistance / Q000235:genetics; D004198:Disease Susceptibility; D005260:Female; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013045:Species Specificity; D014122:Toxoplasma / Q000254:growth & development* / Q000472:pathogenicity; D014124:Toxoplasmosis, Animal / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D016781:Toxoplasmosis, Cerebral / Q000235:genetics / Q000469:parasitology
chemical_list: D052247:Nitric Oxide Synthase Type II; D001119:Arginase; C542908:arginase I, rat
keywords: Arginase-1; Cyst; Host resistance; Neonate rats; Toxoplasma gondii Prugniaud strain; iNOS