Meet Mr. José Manuel Correia da Costa, the master of Toxoplasma gondii.

I am Principal Investigator at the National Institute of Health Dr Ricardo Jorge (INSA - Portuguese State Laboratory). I have done my undergraduate studies on Nutrition and Nutrition and Infection at the University of Porto; graduate studies, including PhD, on Public Health and Developing Countries (Parasitology – Pitié-Salpêtriére) at Pierre and Marie Curie University (Paris VI). In addition, from 2007 to 2009, I was the Director of the National Laboratory of Veterinary Research and member of the Executive Board of the National Institute of Biological Resources (Portuguese State Laboratory). Since 2003 to date, I am the Scientific Coordinator of the Centre for the Study of Animal Science (CECA/ICETA), University of Porto, 211 R&D Unit financed by the Portuguese Foundation for Science and Technology, Evaluation/2017: Excellent.(See more about the career of Mr. J.M. Correia da Costa in the end of the this interview).

The global prevalence of toxoplasmosis is estimated to be around 30% with 10 million clinical cases. Most infections in humans are asymptomatic. However, during my professional duties, I have experienced that severe complications may occur during congenital Toxoplasma infection, ocular toxoplasmosis, or encephalitis in immunosuppressed patients. Current opinion is that the majority of horizontal transmissions to humans occurs after ingestion of tissue cysts in infected meat, or through water, raw fruit and vegetables contaminated with sporulated oocysts. However, the relative importance of transmission via tissue cysts versus oocysts is still unclear. In addition, oocysts can remain viable for long periods in the environment and can resist chemical and physical treatment currently applied in water plants, including chlorination and ozone treatment. What can we do on this topic? When I was informed about SafeConsume project preparation, I have explained all precedent ideas in current laboratorial work. They were accepted and I was enrolled in the SafeConsume team, a fantastic thing.

So far, the detection of Toxoplasma oocysts in fruits, vegetables or water has been difficult, and no standardized methods were available. Moreover, findings outlined in the literature on this topic are scarce and/or controversial. In this scenario, a laboratory approach was designed based on the experience gained with Method 1623.1/EPA for Cryptosporidium oocyst and Giardia cyst detection. This approach involved: the concentration of oocysts from large volumes of washing water (fruit and vegetables), according to Method 1623.1/EPA; and a subsequent application of PCR for identification and quantification of T. gondii DNA. The lack of standardised methods probably sustains the exclusion of T. gondii from regular surveillance systems. Our findings indicate that consumption of raw fruit and vegetables may be a source of T. gondii infection in humans. They also emphasise the need of a procedure accepted with a consensus as the “gold standard” method for the recovery, detection and quantification of T. gondii oocysts and validated for use with fresh fruit and vegetables. Major improvements are still required for routine application at the industrial level or for food testing in laboratories for detection of T. gondii oocysts. In this context, we described a new recombinant TgOWP1 derived-fragment, rTgOWP1-f, as biomarker for environmental oocysts. The TgOWP1 selection was based on its presence in the oocyst wall protein, not detectable in tachyzoites, neither in tissue cysts. The selection of this specific TgOWP1 sequence/fragment was based on its structural homology with a C-terminal sequence of Plasmodium merozoite surface protein I-19 (MSP1–19) and, critically, high diversity comparing with TgOWP family proteins or in similar proteins from Cryptosporidium spp, Besnoitia spp, Hammondia hammondi and Neospora caninum.

Infection with Toxoplasma gondii is complex and its clinical evolution depends on interactions between the parasite and its host. Greater concerns are related to immunocompromised individuals, pregnant women or young females in reproductive age, fertile and seronegative.

Consumers should endogenize regular hygiene practices to minimize the risk of Toxoplasma infection. Vegetables and fruits, usually eaten raw, must be washed well under running water, even those that are purchased in the market with the reference of pre-washed. In the case of lettuce, arugula or other vegetables that make up a salad, it is advisable to remove the washing water in a spiner, before seasoning with oil and vinegar. This way, the risk of ingesting oocysts can be minimized. The consumption of vegetables in the form of soup? Clean and safe. Why not? Meat and animal by-products must be well cooked as a way of inactivating the cysts. Food hygiene from farm to the kitchen, good food preparation, individual hygiene, clean kitchen...

Promote good food choices, support, and encourage hygiene habits in the preparation of meals by consumers.

Hygiene, hygiene, hygiene…

Urogenital schistosomiasis was my first scientific job, in 1982, at the National Institute of Health Dr Ricardo Jorge in Porto, Portugal. In an attempt to ameliorate the diagnosis of the disease, ML Sampaio Silva and André Capron, mine former directors, designed a scientific program and I was a scientific worker among others at Pasteur Institute in Lille, France: production of monoclonal antibodies to characterize Schistosoma haematobium antigens. Why and how urogenital schistosomiasis is associated to bladder cancer. Why does infection with some helminths cause cancer? We have extended our interest to Opisthorchis felineus and O. viverrini associated with colangiocarcinoma integrating TOPIC (Tomsk Opisthorchiasis Consortium). The consortium includes Russia Federation University of Tomsk and University of Novosibirsk, the American George Washington University, Khon Kaen University in Thailand, and the Swiss TPH. Emergent and zoonotic diseases in the context of the One Health are relevant personal scientific topics presenting novel evidences with Safeconsume European Project. Highlights of these studies from our national and international research team include:

• Characterization of Schistosoma haematobium estrogens and the role of estradiol metabolism in urogenital schistosomiasis-induced bladder cancer (Gouveia et al., Cancer Letters, 2015).
• Postulate how the infection with Opisthorchis felineus induces intraepithelial neoplasia of the biliary tract in a rodent model, hypothesizing O. felineus as a type I biological carcinogen (Gouveia et al., Carcinogenesis, 2017; Pakharukova et al., 4Open, 2019).
• Innovative drug repurposing for schistosomiasis: combinations of drugs or biomolecules and elucidating how antioxidants resveratrol and N-acetylcysteine enhance anthelmintic activity of praziquantel and artesunate against Schistosoma mansoni (Gouveia et al., Pharmaceuticals, 2018; Parasite&Vectors, 2019)
• Innovative methods for the detection of environmental oocysts of Toxoplasma gondii (Claudia Marques et al., Parasite&Vectors 2020; Susana de Sousa, Scientific Reports 2020).
• Innovative tool for mobile-based analysis of Malaria-infected thin blood smears: automated species and life cycle stage determination (Rosado et al., Sensors, 2017).