Rapid detection of the novel human pathogen Pantoea piersonii: advancements in methodology

Pantoea piersonii a novel bacterium isolated from the International Space Station (ISS) presents a unique challenge for microbial monitoring in spaceflight and more recently in clinical environments. Identification of the organism currently involves culture, followed by whole genome sequencing and analysis of generated sequences. Since the MALDI-TOF profile of this pathogen is absent from the database and 16S rRNA sequencing fails to resolve its identity to the nearest neighbour, a definitive genetic marker is required for unambiguous identification of the organism. Given the increase in the number of reported clinical cases, there exists a need for a rapid method for identification of the organism which could be utilised in a range of environments including the clinical setting. This study describes the design, development and validation of a specific and sensitive real-time PCR assay for the specific detection of P. piersonii. The assay targets a unique region of the malate dehydrogenase gene, confirmed through comparative genomic analysis. We demonstrate the performance of the assay in terms of analytical specificity, sensitivity, and robustness, ensuring its suitability for both space microbiology applications and clinical use.