Resistant reptiles: How do tuatara shake off Salmonella infection?
Dr Danielle Middleton from Manaaki Whenua Landcare Research hopes to solve the mystery of the tuatara’s remarkable Salmonella resistance – what can we learn from this at-risk relic to protect humans and other animals from disease?
Published on 7 Whiringa-ā-rangi November 2024
As the sole survivors of an ancient line of reptiles, tuatara are one of Aotearoa New Zealand’s most unique taonga and a biological rarity. Dr Middleton and her colleagues have recently discovered that, unlike most reptiles, amphibians, birds and mammals, tuatara are also remarkably resistant to the highly contagious bacterium Salmonella. The team found Salmonella bacteria in tuatara burrows and infecting nearby lizards, but have never observed a single infected tuatara. What makes this species’ immune system so unique?
Dr Middleton and her team have received a Marsden Fund Standard grant to characterise the immune system of tuatara and identify the pathways that protect it from Salmonella infection. They will compare tuatara and other reptile genomes to see if tuatara possess unique immunity genes, and test how blood samples of tuatara respond to infections using innovative immunological experiments. The team suspects that whatever makes the tuatara resistant to Salmonella may protect them from other infectious agents too. All work will be carried out with involvement and consultation from Ngāti Koata and Ngātiwai, who maintain a kaitiaki role over tuatara and the tuatara genome used for this research.
Salmonella is a widespread pathogen that infects nearly all vertebrate animals, and can cause serious illness in humans. By unlocking the secrets of our taonga, this research will broaden our understanding of the evolution of animal immunity, and may reveal new immune pathways or molecules that could be harnessed to improve animal and human health.
Dr Middleton collecting a blood sample from a tuatara (photo supplied)