Meropenem-Resistant Achromobacter xylosoxidans, Subspecies Denitrificans Bacteremia in a Patient With Stage IV Adenocarcinoma of the Lung

Achromobacter xylosoxidans , subspecie s denitrificans is a rare Gram-negative bacillus that causes health care associated infections in immunocompromised hosts. Carbapenems and anti-pseudomonal penicillins are listed as suitable empiric therapy in the literature. Herein, we report a case of a 77-year-old male with stage IV adenocarcinoma of the lung who presented with and was improving from Salmonella javiana enterocolitis, only to subsequently develop A. xylosoxidans , subspecies denitrificans bacteremia that was resistant to both meropenem and piperacillin-tazobactam. With empiric antibiotic coverage falling short of microbial clearance, timely in vitro susceptibility testing and prompt infectious disease consultation are of the utmost importance for treatment.