SUMMARY Toxocara canis and T. cati are highly prevalent nematode infections of the intestines of dogs and cats. In paratenic hosts, larvae do not mature in the intestine but instead migrate through the somatic tissues and organs of the body. The presence of these migrating larvae can contribute to pathology. Toxocara larvae can invade the brains of humans, and while case descriptions of cerebral toxocariasis are historically rare, improved diagnosis and greater awareness have contributed to increaseddetection.Despitethis,cerebralorneurologicaltoxocariasis (NT) remains a poorly understood phenomenon. Furthermore, our understanding of cognitive deficits due to toxocariasis in human populations remains particularly deficient. Recent data describe an enhanced expression of biomarkers associated with brain injury, such as GFAP, APP, transforming growth factor 1 (TGF-1), NF-L, S100B, tTG, and p-tau, in mice receiving even low doses of Toxocara ova. Finally, this review outlines a hypothesis to explore the relationship between the presence of T. canislarvaeinthebrainandtheprogressionofAlzheimer’sdisease

Cerebral Toxocariasis: Silent Progression to Neurodegenerative Disorders?

Factors affecting disease manifestation of toxocarosis in humans: Genetics and environment

Beginning in 1931, an inbred rabbit colony was developed at the Phipps Institute for the Study, Treatment and Prevention of Tuberculosis at the University of Pennsylvania. This colony was used to study natural resistance to infection with tuberculosis (Robertson et al., 1966). Other inbred colonies or well-defined breeding colonies were also developed at the University of Illinois College of Medicine Center for Genetics, the Laboratories of the International Health Division of The Rockefeller Foundation, the University of Utrecht in the Netherlands, and Jackson Laboratories. These colonies were moved or closed in the years to follow. Since 1973, the U.S. Department of Agriculture has reported the total number of certain species of animals used by registered research facilities (1997). In 1973, 447,570 rabbits were used in research. There has been an overall decrease in numbers of rabbits used. This decreasing trend started in the mid-1990s. In 2010, 210,172 rabbits were used in research. Despite the overall drop in the number used in research, the rabbit is still a valuable model and tool for many disciplines.

Biology and Diseases of Rabbits

Fishborne zoonotic heterophyid infections: An update.

In the present study, the incidence and prevalence of coccidian infection among domestic rabbits in Egypt were investigated. Severe overall prevalence reaching 70% (70/100) was recorded. Eight species of Eimeria were detected. Mixed infection with three different species occurred most frequently. Eimeria intestinalis and Eimeria coecicola were generally the most predominant species. The complete life cycle of E. intestinalis was investigated. This study is the first to report coccidia in domestic rabbits in Egypt. Six species of Eimeria were reported for the first time.

Coccidiosis of domestic rabbit (Oryctolagus cuniculus) in Egypt: light microscopic study.

Fecal occult blood manifestation of intestinal Eimeria spp. infection in rabbit.

Freshly defecated unsporulated oocysts of Eimeria piriformis from rabbit were treated with various concentrations (1%, 2.5%, 5%, and 10%) of chromium compounds, potassium dichromate, potassium chromate, chromium oxide and chromium nitrate, to examine their effect on sporulation. The sporulation time of oocysts treated with 1 to 10% K(2)Cr(2)O(7) was 28 h. However, much longer sporulation times of about 60 h were required for oocysts treated with 2.5% CrO(3) and Cr(NO(3))(3). Moreover, for oocysts treated with distilled water, 1% K(2)CrO(4) and 10% K(2)CrO(4), the sporulation times required were 216, 156 and 96 h, respectively. Thus, potassium dichromate was found to have higher catalytic activity for the sporulation of E. piriformis oocysts than other chromium compounds.

Effect of chromium compounds on sporulation of Eimeria piriformis oocysts.

The small intestine is the initial organ which Toxocara canis larvae invade. Information on intestinal pathological changes associated with transforming growth factor-β1 (TGF-β1) and secretory granules (SG) in Paneth cells (PCs) caused by T. canis is unclear. Mice orally inoculated with 250 T. canis infective eggs were evaluated by pathological and immunohistochemical assessments with a 294-day investigation. Pathologically, the inflammatory reactions with or without trapped larvae in the submucosa were observed only within the first 28 days post-infection (DPI), with inflammatory injury ranging from severe during 2 DPI to mild between 7 and 28 DPI. The crypts of Leiberkuhn were major larval penetration sites. Enhanced expression of SG in PCs appeared earlier than those of TGF-β1 in infiltrating cells. The significance of both effectors might be related to the host’s defense against larval invasion in the intestinal phase of toxocaral infection.

Enhanced expression of transforming growth factor-β1 in inflammatory cells and secretory granules in Paneth cells in the small intestine of mice infected with Toxocara canis

Ming-Hsien Li

Papers

Fecal occult blood manifestation of intestinal Eimeria spp. infection in rabbit.

Effect of chromium compounds on sporulation of Eimeria piriformis oocysts.

Enhanced expression of transforming growth factor-β1 in inflammatory cells and secretory granules in Paneth cells in the small intestine of mice infected with Toxocara canis

Infectivity and development of Metagonimus yokogawai in experimentally infected domestic ducks (Cairina moschata).