A 37-week-old infant was delivered by cesarean section and discharged from a Connecticut hospital when he was 10 days old. Two days later he was lethargic and had a fever. When he was readmitted to the hospital, he had multiple brain abscesses caused by Citrobacterdiversus. After a prolonged illness, the baby died. A second infant with a normal pregnancy and delivery died of C. diversus meningitis after a short illness. Nine infants in the hospital nursery had umbilical cord colonization by C. diversus. Environmental cultures were negative for hospital equipment.
a. What is the normal habitat of this gram-negative, facultatively anaerobic, non-endospore-forming, lactose-positive rod?
b. Provide a plan for identifying the source of infection and preventing further infection.