Kerstersia gyiorum Isolated and Identified From the External Auditory Meatus of an Immunocompromised Patient: A Case Report and Literature Review

<i>Kerstersia gyiorum</i>, a rare Gram-negative pathogen first identified in 2003, belongs to the <i>Alcaligenaceae</i> family. Although infrequently reported, it has been isolated from various clinical infections, including wounds, and respiratory tract infections. Our case report highlights an unusual presentation of <i>K. gyiorum</i> in a 13-year-old girl with a complex medical history, associated with external ear pressure ulcers. The unusual, uncommonly identified organism was isolated from an ear swab and identified using MicroScan and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The bacterium exhibited sensitivity to multiple antibiotics but showed notable resistance to aminoglycosides and several common agents, emphasizing the importance of tailored therapy.