Janice had been experiencing mild flu-like symptoms before going into premature labor at seven months. The premature baby boy developed complications immediately after birth, running a fever and demonstrating neurologic abnormalities. A cerebrospinal fluid specimen was collected and a gram stain of the specimen showed short Gram-positive bacilli. The CSF culture grew small beta hemolytic colonies that were catalase positive. A CAMP test was positive on this isolate. The same organism grew from blood cultures done on the baby. What is the most likely identification