title: Early detection of Toxoplasma gondii-infected cats by interferon-gamma release assay.
abstract: Felines, the only definitive hosts that shed the environmentally-durable oocysts, are the key in the transmission of Toxoplasma gondii to all warm-blooded animals. They seroconvert as late as the third week and begin to shed oocysts as early as 3-8 days after being fed tissue cysts. Early detection of Toxoplasma-infected cats is crucial to evaluate Toxoplasma-contaminated environment and potential risks to public health. Moreover, it is fundamental for Toxoplasma infection control. Interferon-gamma release assay (IGRA) is a blood-based test assessing the presence of IFN-γ released by the T-lymphocytes directed against specific antigens, which is an ideal assay for early detection of Toxoplasma-infected cats. Here, cats were orally infected with the tissue cysts and blood was collected for toxoplasmic antigen stimulation, and the released IFN-γ was measured by ELISA. Results showed that Toxoplasma-infection was detected by IGRA as early as 4 days post-infection (dpi); while serum Toxoplasma IgM and IgG were detected by ELISA at 10 dpi and 14 dpi, respectively. Our findings demonstrated that IGRA-positive and ELISA-negative samples revealed an early Toxoplasma infection in cats, indicating a new strategy for the early diagnosis of Toxoplasma infection by combining IGRA and ELISA. Therefore, IGRA could emerge as a reliable diagnostic tool for the exploration of cat toxoplasmosis prevalence and its potential risks to public health.
authors: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China. Electronic address: Engine2010@163.com.
authors: Qing
authors: Q
authors: Yin
authors: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Faculty of Science, Kafr El-Sheikh University, Kafr El-Sheikh, Egypt. Electronic address: saeed_elashram@yahoo.com.
authors: Saeed
authors: S
authors: El-Ashram
authors: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China. Electronic address: jiutouliao1981@163.com.
authors: Xian-Yong
authors: XY
authors: Liu
authors: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, Beijing 100193, China. Electronic address: suoxun@cau.edu.cn.
authors: Xun
authors: X
authors: Suo
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000097:blood / Q000175:diagnosis* / Q000469:parasitology; D002415:Cats; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D005260:Female; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000097:blood / Q000235:genetics; D007371:Interferon-gamma / Q000097:blood* / Q000235:genetics; D059425:Interferon-gamma Release Tests / Q000662:veterinary*; D008297:Male; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D014124:Toxoplasmosis, Animal / Q000097:blood / Q000175:diagnosis*
chemical_list: D007371:Interferon-gamma; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
keywords: Cat; Early detection; Interferon-gamma release assay; Toxoplasma gondii