Case ReportAn Unusual Case of Pyogenic Liver Abscess Secondary to Achromobacter xylosoxidans A Case ReportSaeed, Hasham MD∗; Noori, Muhammad Atif Masood MD†; Jonbos, Maryam MD‡; Jesani, Shruti MD§; Jawed, Qirat MD∥; Salamera, Julius MD, FIDSA¶ Author Information From the Departments of ∗Internal Medicine †Internal Medicine, RWJBarnabas Health/Trinitas Regional Medical Center, Elizabeth, NJ ‡Medical Student, St. George's University–School of Medicine, West Indies, Grenada Departments of §Internal Medicine ∥Internal Medicine ¶Infectious disease, RWJBarnabas Health/Trinitas Regional Medical Center, Elizabeth, NJ. Correspondence to: Hasham Saeed, MD, Department of Internal Medicine, RWJBarnabas Health/Trinitas Regional Medical Center, 225 Williamson St., Elizabeth, NJ 07202. E-mail: [email protected]. The authors have no funding or conflicts of interest to disclose. Infectious Diseases in Clinical Practice 31(2):e1231, March 2023. | DOI: 10.1097/IPC.0000000000001231 Buy Metrics Abstract Achromobacter xylosoxidans is a catalase-positive, oxidase-positive, motile, gram-negative rod. When isolated, it is usually a cause of bacteremia in immunocompromised patients. Here we present a case of liver abscess caused by this rare organism in an immunocompetent host. A 57-year-old Colombian woman came to the emergency department with complaints of subacute onset of back pain, burning in urination, fever, nausea, and vomiting. She was febrile and tachycardic. Urinalysis was positive for leukocyte esterase, nitrite, and bacteria. The patient was started on empiric piperacillin tazobactam 3375 mg as intravenous piggyback every 8 hours. On day 3 of hospitalization, the patient continued to experience flank pain without improvement. Computed tomographic scan of the abdomen and pelvis with contrast revealed 2 thick-walled complex collections in the right hepatic lobe and the caudate lobe of the liver. Purulent aspirate grew A. xylosoxidans. In this report, we explore the characteristics of A. xylosoxidans and the associated infections it is known to cause as well as suggested treatments from previously reported cases. Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.