Partial (∼ 780 bp) mitochondrial cytochrome c oxidase subunit I (COI) and near complete nuclear 18S rDNA (∼ 1,780 bp) sequences were directly compared to assess their relative usefulness as markers for species identification and phylogenetic analysis of coccidian parasites (phylum Apicomplexa). Fifteen new COI partial sequences were obtained using two pairs of new primers from rigorously charac...

Toxoplasma gondii has evolved a number of strategies to evade immune responses in its many hosts. Previous genetic mapping of crosses between clonal type 1, 2, and 3 strains of T. gondii, which are prevalent in Europe and North America, identified two rhoptry proteins, ROP5 and ROP18, that function together to block innate immune mechanisms activated by interferon gamma (IFNg) in murine hosts. ...

Infection by Toxoplasma gondii affects around one-third of world population and the treatment for patients presenting toxoplasmosis clinically manifested disease is mainly based by a combination of sulfadiazine, pyrimethamine, and folinic acid. However, this therapeutic protocol is significantly toxic, causing relevant dose-related bone marrow damage. Thus, it is necessary to improve new approa...

UNLABELLED PURPOSE. This study was performed to characterize the clinical, serologic, histopathologic, and immunohistochemical features of an experimental model of ocular toxoplasmosis in cats. METHODS Seven specific pathogen-free cats were inoculated in the right carotid artery with 5 x 10(3) tachyzoites of the ME49 strain of Toxoplasma gondii. Control cats received heat-killed tachyzoites. ...

In their letter, McConkey et al. (1) suggest that differences in study design may have led to different results in our study compared with those of previous reports. In an effort to better understand these differences, we welcome the opportunity to provide more insight into the rationale for our study design and the reasoning behind the interpretations we reached. We stress at the outset that w...

Integrated databases resources are integral to the study of biology and of host-pathogen interactions. Tremendous strides in technology have permitted the generation of large, valuable data sets for many life cycle stages of numerous pathogens and/or their hosts. The Toxoplasma genome database (http://ToxoDB.org) currently hosts, and integrates, a wide array of diverse, large-scale data sets (1...

In their letter, McConkey et al. (1) suggest that differences in study design may have led to different results in our study compared with those of previous reports. In an effort to better understand these differences, we welcome the opportunity to provide more insight into the rationale for our study design and the reasoning behind the interpretations we reached. We stress at the outset that w...

Since there is a remarkable difference in susceptibility to peroral infection with Toxoplasma gondii among inbred strains of mice, we performed studies to examine the mechanism(s) of this difference in susceptibility. After peroral infection with the ME49 strain of T. gondii, C57BL/6 (B6) mice all died whereas BALB/c mice all survived. At day 7 of infection (when B6 mice began dying), massive n...

Mitochondria, the powerhouses of eukaryotic cells, regulate many pathways related to cell growth and division. They also participate in apoptotic cell death and survival pathways such as autophagy and in innate immune responses. As such, mitochondria are a tempting target for intracellular pathogens, which may seek to block or manipulate mitochondrial activity to meet their own needs. Sometimes...