Pantoea piersonii (basionym kalamiella piersonii) as an emerging pathogen: clinical manifestations, diagnostic challenges, and resistance threats.

A bacterium, Kalamiella piersonii, first identified from the ISS, later reclassified as Pantoea piersonii has emerged as an opportunistic pathogen of global clinical relevance. It was initially predicted to be nonpathogenic; however, subsequent reports have shown it to be associated with human infections, capable causing bacteremia, and sepsis across different patient populations. The genome of P. piersonii encodes several virulence genes involved in adhesion, invasion, and colonization, enabling its successful infection in diverse body sites. Given its environmental resilience, metabolic adaptability, and pathogenic potential, P. piersonii represents an under-recognized but important emerging pathogen. The frequent misidentification of Pantoea species due to limitation in the existing routine clinical diagnostic methods may contribute to rise of AMR due to non-specific antibiotic use. This underscores the need to compile existing knowledge on this pathogen that can support the development of accurate identification tools. This will help in better surveillance to prevent its spread and mitigate the global AMR burden to achieve the sustainable developmental goal.