Through sustained laboratory work and collaboration, researchers at PHF Science, working with colleagues at Queensland Health, have identified and formally described a new bacterial species: Yersinia fenwicki.
The organism has been isolated from human cases of acute gastroenteritis in both New Zealand and Australia. The findings, published in the International Journal of Systematic and Evolutionary Microbiology, add to the growing catalogue of bacteria which may be associated with gastrointestinal illness and help refine how such organisms are detected and understood.
From routine testing to a new species
The discovery did not come from a single defining moment, but from a line of inquiry evolving over decades. During routine testing of faecal samples in 2010, researchers at PHF Science’s Enteric Reference Laboratory noticed a small number of bacterial isolates not matching any known species, noting their resemblance to a rare variant of Yersinia enterocolitica first reported in New Zealand 1996.
While initial results were uncertain, the emergence of similar isolates in follow-up samples led researchers to investigate further. The adoption of more advanced genomic methods at PHF Science allowed the team to compare these organisms in greater detail, revealing consistent differences from recognised Yersinia species.
In 2023, laboratories at Queensland Health identified comparable isolates. This overlap prompted a trans-Tasman collaboration, bringing together data and expertise to confirm that the bacteria represented a previously unrecognised species.
Together, this careful observation, improved analytical tools, and cross-border collaboration led to the formal identification of Yersinia fenwicki.
Honouring a scientific legacy
The species was named Yersinia fenwicki in honour of Emeritus Professor Stanley Fenwick, whose work on Yersinia at New Zealand's Massey University helped lay the foundations for the discovery.
Fenwick called the recognition “an incredible honour”, adding that “good deeds have a long reach.” Now based in Bangkok, he works internationally on One Health and antimicrobial resistance, and remains closely connected to the field.
Why this discovery matters
Identifying a new bacterial species is not just an academic exercise. It improves our understanding of infectious diseases, helps refine diagnostic methods, and supports better public health responses. Knowing exactly which organism is causing illness allows scientists and clinicians to track its spread, study its behaviour, and respond more effectively.
It also highlights the importance of strong partnerships, within New Zealand and internationally. By sharing knowledge, data and expertise, scientists were able to achieve something no single team could have done alone. More than just the identification of a new species, this is an example of how science progresses: step by step, across years and generations, building on past work to create new understanding.
An important discovery, a lasting tribute and a powerful reminder of what collaboration can achieve.