Background: Streptococcus pasteurianus is a rare cause of neonatal infection, with only 3 cases reported in the USA and 18 cases reported in other countries within the past decade. Neonatal S. pasteurianus infection typically presents as meningitis. This case report describes the first neonatal case of S. pasteurianus endocarditis in the literature, in addition to a neonatal case of S. pasteurianus infection presenting as pneumonitis without meningitis. The S. pasteurianus infections in these two cases are unusual not only because of how rare this particular pathogen is, but also because of the atypical clinical manifestations.
Case presentation: The first patient is a full-term male infant admitted to NICU at 20 h of life due to respiratory distress. He was empirically started on ampicillin and gentamicin for presumed sepsis. Laboratory analysis of cerebral spinal fluid obtained after initiation of antibiotics was suggestive of partially treated meningitis. Blood cultures came back positive for S. pasteurianus. The neonate was transitioned from ampicillin to cefepime, while gentamicin was continued. Echocardiograph showed a possible tricuspid valve vegetation concerning for endocarditis. Due to the unusual complication of endocarditis, the patient remained on IV cefepime for 28 days rather than the more conventional duration of 14-21 days reported in the literature. The baby clinically improved with no evidence of thrombi or vegetations on repeat cardiac echo. The second patient is a full-term male infant who required intubation at birth for respiratory distress. Chest X-ray findings were concerning for meconium aspiration with pneumonitis. The baby went into septic shock and was empirically started on ampicillin and gentamicin. Blood cultures came back positive for S. pasteurianus, while cerebral spinal fluid and urine cultures were negative. Ampicillin and gentamicin were discontinued after 3 days and the baby was started on cefepime and clindamycin for a total 14-day course. The baby clinically recovered and was discharged from NICU without any sequelae.
Conclusions: These two cases highlight the importance of recognizing S. pasteurianus as a potential cause of neonatal sepsis and the importance of recognizing endocarditis and pneumonitis as possible clinical manifestations of this infection.
Keywords: Endocarditis; Meconium; Meningitis; Pneumonitis; Sepsis; Streptococcus pasteurianus.