Article in Japanese

Pneumonia caused by Streptococcus agalactiae triggered from airway management in a preterm infant

Kota NAGAI^1）, Masahiro KINOSHITA^1）, Atsushi MIYAKE^{1, 2）}, Kazuaki TATARA^1）, Kiyohito OKUMIYA^1）, Kenji GOTOH^{1, 2）}

Decolonization of Streptococcus agalactiae in neonate remains a subject of controversy because of the reported instances of delayed invasive infections in preterm infants and horizontal transmission within neonatal intensive care units. Here, we report a case of delayed invasive pneumonia following airway management in a carrier of S. agalactiae. The patient was admitted to the hospital as a preterm, very-low-birth-weight infant at 27 weeks and 0 days of gestation, and initial culture tests conducted at birth yielded negative results. At 56 days of age, the patient underwent general anesthesia and tracheal intubation for an intraocular ranibizumab injection to address retinopathy of prematurity. However, the patient’s respiratory condition rapidly deteriorated on the subsequent day, and a strain of S. agalactiae was isolated from tracheal and blood cultures taken at that time, leading to diagnoses of pneumonia with sepsis. The effective administration of antimicrobial treatment resulted in the patient’s discharge without any subsequent neurological complications. A follow-up examination of the nasal surveillance culture conducted before the onset of pneumonia confirmed the patient’s carrier status for S. agalactiae, thus indicating that the tracheal intubation procedure led to the progression of pneumonia. The isolated strain was classified as serotype V and exhibited the genotype ST-19, which is frequently associated with carriers of S. agalactiae. In individuals carrying S. agalactiae, the prophylactic administration of antimicrobials before invasive procedures, such as airway management, may be considered beneficial.

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1） Department of Pediatrics and Child Health, Kurume University School of Medicine
2） Department of Infection Control and Prevention, Kurume University School of Medicine

Key words	Streptococcus agalactiae, neonatal intensive care unit, pneumonia, late-onset infections, carrier
Received	June 6, 2023
Accepted	September 16, 2023

35 (4)：357─363,2023