Case of the Month - May 2021 A 66-year-old man was brought to the Emergency Room after being found on the floor of his apartment with abdominal pain and vomiting for several days. On physical exam, he was hypotensive and hypothermic, with slurred speech, abdominal tenderness and a firm, tender, non-reducible hernia. He underwent an emergent exploratory laparotomy with herniorrhaphy and resection of bowel. Postoperatively, he remained on mechanical ventilation and pressors, and required a second laparotomy two days later. His postoperative course was further complicated by acute hypoxic respiratory failure. Klebsiella pneumoniae grew from respiratory cultures. He remained in septic shock and respiratory failure, and several days later underwent a third surgical procedure for abdominal closure and creation of an ileostomy. Two days later, he developed fever and a new respiratory culture was ordered, which yielded Stenotrophomonas maltophilia. Its growth on chocolate agar is shown in Figure 1. A further review of the Gram stain showed the organism shown in Figures 2 and 3. Ova and parasite examination of the respiratory specimen and stool was diagnostic. What is the organism? Figure 1 – Bacterial growth in serpentine tracks outside the streaking patch on chocolate agar. Figure 2 – Gram stain, 100X magnification of a respiratory specimen. Organisms with one pointed end and one rounded end on a background of many white blood cells. Figure 3 – Gram stain, 500X magnification (oil immersion).