Toxoplasma gondii and Neospora caninum Infections in Stray Cats and Dogs in the Qinghai–Tibetan Plateau Area, China

Abstract

Toxoplasma gondii and Neospora caninum belong to the Apicomplexan protozoa which is an obligate intracellular parasite, causing toxoplasmosis and neosporosis throughout the world. Cats and dogs are the definitive hosts of these two parasites. However, information on the epidemiology of toxoplasmosis and neosporosis in stray cats and dogs in the Qinghai–Tibetan Plateau Area (QTPA) is limited, and little is known about the diversity of the diseases. Therefore, the aim of this study was to perform indirect ELISA tests based on recombinant TgSAG1, TgGRA1, NcSAG1 and NcGRA7 proteins to establish a detailed record of the seroprevalence of T. gondii and N. caninum-specific IgG and IgM antibodies in serum samples and to develop qPCR amplification based on TgB1 and NcNc5 genes to conduct molecular epidemiology in feces from stray cats and dogs in the QTPA. In the current study, a total of 128 cat serum samples were analyzed through serological tests in which 53 (41.4%) and 57 (44.5%) samples were found positive for T. gondii specific-IgG and IgM antibodies, and 2 (1.6%) and 74 (57.8%) samples were confirmed positive for N. caninum specific-IgG and IgM antibodies, respectively. Out of 224 stray dog sera, 59.8% and 58.9% were recorded as positive against anti-Toxoplasma IgG and IgM antibodies, 17.9% and 64.7% were detected positive against Neospora IgG and IgM. On the other hand, 1 of 18 cat fecal samples was successfully amplified within the Ct value of 10 to 30 while no cat was positive for neosporosis. Moreover, a higher prevalence of toxoplasmosis in stray dogs (14.5%, 16/110) than of neosporosis (5.5%, 6/110) with different parasite numbers were found. Further analysis showed that no significant sex differences were found nor between the overall infection rates of T. gondii and N. caninum in this study. This study suggests that stray cats and dogs play key roles in the transmission and prevalence of T. gondii and N. caninum in the plateau area.

Seroepidemiological Survey of Anti-Toxoplasma gondii and Anti-Neospora caninum Antibodies in Domestic Cats (Felis catus) in Rolim de Moura, State of Rondônia, North Brazil

“…Cats are more resistant and less exposed to N. caninum, with a very low or absent prevalence of antibodies being observed [40,41]. There is still little information on the pathogenesis of neosporosis in cats [10].…”

“…Cats are intermediate hosts, in which the close contact with dogs can promote high seropositivity rates of IgM anti-N. caninum. However, it has been observed that only a small number of cats previously infected with N. caninum persisted with antibodies for a long time [10].…”

Seroepidemiology of Neosporosis in Various Animals in the Qinghai-Tibetan Plateau

“…Intermediate hosts probably become infected with N. caninum mainly through ingestion of foods or drinking water contaminated by sporulated N. caninum oocysts ( 1 – 3 ). Most of the pig samples in this study were collected from Xining and Haidong cities, and the sampling areas seem to present a large number of important risk factors such as stray dogs for N. caninum infection ( 28 ). Moreover, the current pig farms in the Qinghai-Tibet Plateau are non-intensive farming, which means more convenient conditions for N. caninum oocysts seeded by the dogs are exposed to pigs.…”

Application of Toxoplasma gondii-specific SAG1, GRA7 and BAG1 proteins in serodiagnosis of animal toxoplasmosis

“…Moreover, the chicken’s habit of pecking the soil may lead to greater exposure to the threat of oocysts ( Wang et al., 2015 ). Certainly, in areas with the prevalence of toxoplasmosis, the definitive-host cats, especially stray cats, play a key role in frequently exposing other animals to the infectious source and causing T. gondii infections in the Qinghai-Tibetan Plateau ( Xia et al., 2022 ; Yang et al., 2022 ).…”