Catheter-Associated Soft Tissue Infection Caused by Pantoea piersonii in a Totally Implantable Venous Access Port: The First Report from China.

Pantoea piersonii (formerly Kalamiella piersonii) is a recently reclassified environmental Gram-negative bacterium belonging to the family Erwiniaceae. Human infections caused by this organism are extremely rare. Here, we report a rare case of implantable venous access port-associated soft tissue infection caused by P. piersonii in a 49-year-old immunocompromised woman with lung cancer. The pathogen was isolated from purulent discharge obtained from the port site and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Whole-genome sequencing confirmed species-level identification based on average nucleotide identity (ANI) analysis and phylogenomic reconstruction. The isolate exhibited broad antimicrobial susceptibility to the tested agents. Following complete device removal and empirical antimicrobial therapy, the patient recovered uneventfully. This study reports the first documented case of P. piersonii infection in China and provides a comprehensive clinical and genomic characterization of a newly isolated clinical strain.