Kerstersia gyiorum is an uncommon opportunistic pathogen rarely isolated in human infection. Most reported cases have concerned patients with otitis media. We describe a case of a 73-year-old patient with type 2 diabetes who developed bilateral otorrhea following head trauma in Morocco. Cytobacteriological analysis of the purulent ear discharge revealed polymicrobial infection with the presence of Kerstersia gyiorum, Escherichia coli, and Achromobater xylosoxidans, which were identified using MALDI-TOF MS. Our study highlights the importance of using advanced identification techniques, such as MALDI-TOF MS, for the detection of uncommon and underrecognized pathogens.

Keywords: Kerstersia gyiorum; Rare pathogen; Purulent ear discharge; MALDI-TOF MS