Eco-epidemiology and genetic characterisation of Toxoplasma gondii in wildlife landscapes in the Greater Kruger, South Africa

Abstract

Toxoplasma gondii is a protozoan parasite that causes the zoonotic disease, toxoplasmosis. The definitive hosts are felids; however, this parasite infects a diverse range of homeothermic intermediate hosts. Despite its prevalence, there is limited knowledge about the seroprevalence and strain diversity of Toxoplasma in southern Africa. Thus, the first part of the study aimed to determine the seroprevalence of T. gondii in some wildlife in Kruger National Park (KNP, South Africa). We analysed the seroprevalence in retrospective (2015 – 2023) wildlife serum samples from the KNP using the modified agglutination test (MAT). The results highlighted that the highest seroprevalence was observed in lion (Panthera leo) (n = 136, 91.2%) and leopard (Panthera pardus) (n = 18, 88.9%), followed by spotted hyaena (Crocuta crocuta) (n = 88, 65.9%). The seroprevalence among herbivores and omnivores was as follows: hippopotamus (Hippopotamus amphibius) (n = 35, 51.4%), white rhinoceros (Ceratotherium simum) (n = 138, 29%), African elephant (Loxodonta africana) (n = 138, 21.7%), African buffalo (Syncerus caffer) (n = 137, 18.2%), black rhinoceros (Diceros bicornis) (n = 35, 17.1%) and warthog (Phacochoerus africanus) (n = 35, 14.3%). In short, the results showed that carnivores have a statistically higher seroprevalence compared with both herbivores and omnivores. This part of the study provides a better insight into the eco-epidemiology of Toxoplasma in the KNP, and the role of diet in potentially influencing the seroprevalence of Toxoplasma. The second part of the study aimed to identify and genetically characterise T. gondii in wildlife in the Greater Kruger region (South Africa). Toxoplasma DNA was identified using a qPCR and genotyped using 15 established microsatellite markers. Toxoplasma DNA was found in the brain and tongue of two impala (Timbavati Private Nature Reserve, South Africa) and was genotyped as Africa 4 strains. These results add to the existing knowledge of the specific T. gondii strains present in wildlife in the Greater Kruger region.