A Comparative Histopathology, Serology and Molecular Study, on Experimental Ocular Toxocariasis byToxocara catiin Mongolian Gerbils and Wistar Rats

Abstract

The aim of this study was to compare the performance of three in-house diagnostic tests, that is, histopathology, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR), for the diagnosis after experimental infection with Toxocara cati. Twenty Mongolian gerbils and Wistar rats were divided into ten groups (n = 2/group). Toxocara cati infections were established in Mongolian gerbils and Wistar rats by administering doses of 240 and 2500 embryonated Toxocara cati eggs by gavage, respectively. Tissue sections were stained with Haematoxylin and Eosin and observed under the light microscope. Sera and vitreous fluid collected from separate infected groups were tested against Toxocara cati antigens, for 92 days postinfection. Genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) blocks, and aqueous fluids belong to the animals. The histopathology test gave negative results among the groups of animals examined between 5 and 92 days postinfection. The ELISA results showed that anti-Toxocara antibodies have risen between 7 and 61 days postinfection in sera and vitreous fluid in the animals infected, respectively. Analysis of PCR products revealed positive band (660 bp) in the orbital tissue infected Mongolian gerbils at 5 days postinfection. Of the three evaluated methods, the PCR could be recommended for scientific and laboratory diagnoses of toxocariasis in experimentally infected animals.

Prevalence of Toxocara and Toxascaris infection among human and animals in Iran with meta-analysis approach

“…However, such examination is invasive and relies on the larval load and the infection phase [28]. Therefore, routine diagnosis of infection and/or exposure in human cases can be done by ELISA to detect specific antibody against TES antigens, which should be further validated by immunoblotting [37,38]. As previously mentioned, TES-based ELISA tests are mostly used for human seroprevalence studies.…”

Environmental soil contamination by <i>Toxocara</i> species eggs in public places of Ilam, Iran

“…Most infections do not have any clinical symptoms, athough Toxocara larvae are released within the different tissues and organs and may cause dangerous clinical syndromes, including weight loss, fever with a cough and shortness of breath, generalized lymphadenopathy and hepatomegaly [6][7][8]. The diagnosis of human toxocariasis is mainly based on clinical symptoms, epidemiological and laboratory data, which include imagining features, peripheral blood eosinophil, total IgE level, and serological findings using Enzyme-linked immunosorbentassay (ELISA) and Western blotting (WB) [9]. In big cities, the soils of the public places, such as green spaces, can become an important source of parasites contamination because domestic and stray dogs and cats have the highest mobility in these areas.…”

A new era of uveitis: impact of polymerase chain reaction in intraocular inflammatory diseases

“…Therefore, the serum antibody measurements of Toxocara larva should be interpreted with care, while the detection of the antibodies in intraocular fluids has greater diagnostic value [130]. Although the molecular diagnosis of Toxocara larva has been reported by using liver biopsy specimens [131], experimental animal models of ocular toxocariasis [132], or carnivore feces [133], PCR assays are less frequently used to diagnose ocular toxocariasis using results of the multiplex PCR using the aqueous humor of the eye were positive for Toxoplasma gondii DNA, and real-time PCR revealed 1.1 9 10 6 copies/ml. Reproduced from Sugita et al [13] with permission Fig.…”