Pantoea calida bacteremia in an adult with end-stage stomach cancer under inpatient care

Abstract Pantoea calida is a gram-negative bacillus that was first identified in 2010. Here, we describe the first known case of P. calida bacteremia in a 77-year-old woman with end-stage stomach cancer under inpatient care. The patient was admitted to our hospital for pain after receiving anti-cancer therapy at outpatient facility. Thirteen days after admission, her temperature rose to 39.6 °C. A blood culture was ordered for suspected bacterial infection, and the patient was treated empirically with ampicillin/sulbactam. Cultures showed white pitting colonies later identified as a Pantoea sp. by biochemical analysis. The isolate’s 16S rRNA sequence was identical to that of P. calida (100%), and showed 99.1% similarity with that of Pantoea gaviniae . Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) confirmed the species as P. calida with an average spectral score > 2.0. The primary isolate was ampicillin-resistant, but susceptible to other antibiotics and the bacteremia was cleared after three days of antibiotic therapy. Since P. calida infection is relatively rare, limited information exists on the pathogen’s portal of entry and bacterial characteristics; thus, further studies are necessary to establish the pathophysiological mechanisms P. calida infection.