A collaborative research project involving the University of the Free State (UFS) has earned international recognition after Laura Stein, a veterinary doctorate student in the Section of Veterinary Bacteriology at the University of Zurich, received the Young Scientist Award at the VPH Conference 2025.

Stein was recognised for her poster titled Evaluating the QuantiFERON-TB Gold Plus Immune Assay and EspC Peptides for Bovine Tuberculosis Detection, which focuses on improving diagnostic tools for bovine tuberculosis (bTB) – a disease with serious implications for livestock, wildlife, and human health worldwide.

International collaboration with strong UFS involvement

Stein’s research is closely linked to the UFS through Prof Wynand Goosen from the Department of Microbiology and Biochemistry in the Faculty of Natural and Agricultural Sciences. Prof Goosen serves as her co-supervisor and oversees all work involving the South African samples used in the study.

This collaboration builds on an established partnership between Prof Goosen and Stein’s primary supervisor, Dr Giovanni Ghielmetti, and continues through further joint research between the University of Zurich and the UFS.

Stein explains that she began her doctoral work in May 2025 – at a time when her supervisor was already collaborating closely with Prof Goosen on South African sample collections and analyses. This existing collaboration became the foundation for her involvement, with Prof Goosen now serving as her co-supervisor.

Reflecting on the partnership, Stein says: “This partnership is both personally rewarding, because I can work with and learn from experts, and professionally significant, as it allows my research to have direct relevance to real-world disease control challenges.”

Addressing limitations in current bTB diagnostics

Bovine tuberculosis, mainly caused by Mycobacterium bovis, is usually diagnosed using skin tests or blood-based assays that measure an animal’s immune response to bacterial proteins. Stein notes that current diagnostic methods still rely on purified protein derivatives (PPDs), which present significant limitations.

According to Stein, these tests cannot distinguish between infected and vaccinated cattle and are prone to cross-reactions with non-tuberculous mycobacteria. As a result, vaccination cannot be implemented because existing tests would misclassify vaccinated animals as infected, while cross-reactivity reduces diagnostic specificity, particularly in regions where environmental mycobacteria are common.

She explains that human medicine has already addressed these challenges through DIVA-compatible assays that use well-defined antigens to detect infection without interference from vaccination. One such example is the QuantiFERON®-TB Gold Plus (QFT-Plus) assay, which was designed to identify latent tuberculosis infection in humans while avoiding cross-reactivity with the BCG vaccine. Her research aims to transfer this principle to cattle by adapting the QFT-Plus assay for bovine use. In addition, she assessed EspC peptides as another promising set of defined antigens with the potential to further enhance sensitivity and specificity in a bovine DIVA context.

Testing under real-world conditions

To evaluate the diagnostic performance of these newer approaches, the study compares two cattle cohorts: 100 dairy cows in Switzerland, an officially bTB-free country, and 200 cattle from bTB-endemic areas in South Africa, where the true infection status is unknown.

Stein explains that Swiss cattle provide a reliable negative reference group for assessing specificity, while testing animals under endemic conditions in South Africa is essential for understanding real-world assay performance. She adds that Prof Goosen’s extensive experience in mycobacterial research and diagnostic evaluation added significant scientific value to the project.

South Africa’s epidemiological context presents unique challenges, including the presence of bovine tuberculosis in both cattle and wildlife, a higher prevalence of environmental mycobacteria, extensive wildlife–livestock interfaces, and practical constraints such as movement restrictions during foot-and-mouth disease outbreaks and limited traceability in communal farming systems. Together, these factors make South Africa a particularly valuable setting for testing diagnostic tools under real-world conditions.

Promising early results

Preliminary results from the Swiss cohort show that traditional PPD-based tests produced more false-positive results than the newer methods. Two cows tested positive using PPDs but were negative when assessed with both QFT-Plus and EspC peptides. QFT-Plus and EspC each identified one animal as positive.

Stein notes that this outcome aligned with expectations, as the antigens used in the newer assays are more specific than the broad PPD preparations used in conventional tests. Continuing work includes refining cut-off values and culturing nasal swabs and faecal samples from positive animals to assess whether environmental mycobacteria may be influencing test results.

Recognition with global relevance

Receiving the Young Scientist Award was an important milestone for Stein and helped raise the visibility of her work. Reflecting on the recognition, she says: “I am honoured to receive this award. It provides an important platform to highlight that bovine tuberculosis remains a significant global disease, even in countries that are officially free of it.”