Staphylococcus lugdunensis Bacteremia with an Infected Aortic Thrombus in a Preterm Infant.

Staphylococcus lugdunensis is a rare cause of late-onset sepsis in preterm infants. To our best knowledge, we report the fourth case of a male preterm infant who developed fulminant late-onset sepsis due to Staphylococcus lugdunensis with persistent bacteremia secondary to an infected aortic thrombus confirmed with two positive blood cultures. Our patient was an extremely low birth weight growth-restricted infant born at 27 weeks gestation and initially required an umbilical arterial catheter for blood pressure and blood gas monitoring. The course of this neonate was complicated by severe respiratory distress syndrome that evolved into chronic lung disease along with multiple episodes of tracheitis. Hemodynamically, the infant had a significant patent ductus arteriosus, and an episode of medical necrotizing enterocolitis followed by Staphylococcus lugdunensis septicemia. He was diagnosed with an infected aortic thrombus, probably the occult focus responsible for the persistent bacteremia. After a 6-week course of intravenous antibiotics and 4-week course of anticoagulant therapy, the infant responded and recovered without complications.