An interdisciplinary team from the UK and Brazil have been awarded a grant worth over half a million pounds to help determine how disease caused by one of the most common parasitic infections in the world progresses in warm blooded animals, and how it is transmitted in food.
Toxoplasma gondii (T. gondii)
is a parasite that can infect all warm-blooded animals, with up to one third of humanity potentially having been exposed. In particular, it can cause severe disease in pregnant women and those who are immune-compromised, and in sheep it is a major cause of abortion. People and animals can become infected through ingestion of parasite eggs (oocysts) from cat faeces, ingestion of undercooked meat containing parasite cysts or from mother to foetus during pregnancy. Toxoplasmosis is now recognised as one of the most important foodborne diseases worldwide.
The joint three-year grant from the Biotechnology and Biological Sciences Research Council and the Fundação de Amparo à Pesquisa do Estado de São Paulo (BBSRC-FAPESP) will greatly improve understanding of foodborne transmission and the infectious nature of T. gondii, and will aid related future research in vaccine design and drug discovery.
There is huge variation between different strains of the parasite regarding disease severity and T. gondii strains from South America are known to cause serious disease compared to strains found in other parts of the world. The reasons why some T. gondii strains cause more severe disease than others are not known and it is vital to develop new laboratory models to improve our understanding of the infection process and the critical factors in involved in determining virulence.
The project, led by the Moredun Research Institute working in collaboration with colleagues at University of São Paulo in Brazil, Newcastle University and Biomathematics and Statistics Scotland will use cells and 3D “mini-guts” (fully functioning, lab-grown gut tissue) from different host species to develop a more relevant, host-specific system for determining the severity of infection by T. gondii and predicting how the disease will progress. The project will also assess the prevalence of T. gondii in a large study of retail meat samples in São Paulo, and the level of infectiousness of any parasites isolated from meat products can be assessed using the mini-guts to help determine the risk to public health.
Dr Clare Hamilton, Moredun Research Institute and Project lead said “This exciting, collaborative project will not only improve our understanding of Toxoplasma virulence in different hosts which could help aid future vaccine development and control strategies, it also has the potential to develop new culture-based systems to assess infectivity and virulence of different parasite strains. I am delighted to be working with all of our partners and look forward to seeing the results of the next 3 years.”
Dr Hilda Fátima de Jesus Pena, University of São Paulo, Brazil, said “Brazil is considered a hotspot for T. gondii genetic diversity. This diversity is linked with a high occurrence of ocular toxoplasmosis in some regions of the country and severe cases of congenital toxoplasmosis. In general, seroprevalence to the parasite is high all over the country both in human and animal populations. This project will be a great opportunity to investigate T. gondii strains and their viability in different types of meat consumed by the population of São Paulo, the largest city of South America in terms of its population and economy.”