A female neonate born at 28 weeks gestation has meconium-stained amniotic fluid. Physical exam shows an erythematous rash with small, pale papules; tone is poor and apnea episodes have occurred. The organism most likely responsible for this neonate's infection is

A female neonate born at 28 weeks gestation has meconium-stained amniotic fluid. Physical exam shows an erythematous rash with small, pale papules; tone is poor and apnea episodes have occurred. The organism most likely responsible for this neonate's infection is

• A. Listeria
• B. Group B Streptococcus
• C. Staphylococcus aureus
• D. Escherichia coli

Answer: (A)

Disseminated neonatal infection with granulomatous skin lesions is a classic clue for Listeria monocytogenes. In newborns, Listeria can cross the placenta and cause early-onset sepsis with widespread microabscesses and granulomatous dermatitis, which can present as an erythematous rash with small pale papules. The combination of prematurity, meconium-stained amniotic fluid (a sign of fetal stress often linked to intrauterine infection), and repeated apnea with poor tone fits a disseminated infectious process in which the skin lesions reflect underlying granulomatous inflammation from Listeria. Group B Streptococcus is the most common cause of early-onset neonatal sepsis, but the rash described is more characteristic of disseminated granulomatous infection seen with Listeria rather than the typical presentation of GBS. Staphylococcus aureus would usually present with localized skin or soft-tissue involvement or a different pattern of bacteremia, and Escherichia coli is another common sepsis culprit but does not typically produce these pale papular skin lesions.

Disseminated neonatal infection with granulomatous skin lesions is a classic clue for Listeria monocytogenes. In newborns, Listeria can cross the placenta and cause early-onset sepsis with widespread microabscesses and granulomatous dermatitis, which can present as an erythematous rash with small pale papules. The combination of prematurity, meconium-stained amniotic fluid (a sign of fetal stress often linked to intrauterine infection), and repeated apnea with poor tone fits a disseminated infectious process in which the skin lesions reflect underlying granulomatous inflammation from Listeria.

Group B Streptococcus is the most common cause of early-onset neonatal sepsis, but the rash described is more characteristic of disseminated granulomatous infection seen with Listeria rather than the typical presentation of GBS. Staphylococcus aureus would usually present with localized skin or soft-tissue involvement or a different pattern of bacteremia, and Escherichia coli is another common sepsis culprit but does not typically produce these pale papular skin lesions.