Infections: Clinical Characteristics and Therapeutic Challenges of an Uncommon Pathogen.

is a rare opportunistic pathogen of the Enterobacteriaceae family, typically regarded as a gastrointestinal commensal. However, it has been implicated in serious infections, particularly in immunocompromised patients, posing diagnostic and therapeutic challenges. We present the case of a 70-year-old woman with a history of cryptogenic cirrhosis postliver transplant, complicated by sepsis and advanced pancreatic adenocarcinoma under palliative care. She developed a urinary tract infection caused by and , confirmed by cultures. Despite targeted antibiotic therapy with vancomycin and ciprofloxacin, her condition deteriorated, leading to death due to oncologic disease progression. This case underscores the pathogenic potential of , its role in polymicrobial infections, and the importance of antimicrobial susceptibility testing. Raising awareness of this under-recognized pathogen is crucial to improving outcomes in vulnerable populations.