Effects of Intrapartum Antibiotic Prophylaxis on Neonatal Acquisition of Group B Streptococci

Meiwa Toyofuku, Miyuki Morozumi, Mariko Hida, Yoshitake Satoh, Hiroshi Sakata, Hiroyuki Shiro, Kimiko Ubukata, Mitsuru Murata, Satoshi Iwata

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10 Citations (Scopus)


Objectives To assess the incidence of colonization with group B streptococci (GBS) among neonates as influenced by maternal GBS carriage and intrapartum antibiotic prophylaxis (IAP). Study design Between October 2014 and May 2015, nasopharyngeal and rectal swab samples were collected from 730 neonates at 1 week and 1 month after birth. GBS and capsular serotype were identified by real-time polymerase chain reaction and by culture. IAP at delivery was determined retrospectively from hospital records. Results Sixty-four neonates (8.8%) were GBS-positive by real-time polymerase chain reaction and culture. Among neonates born to mothers who were GBS carriers (n = 107), 94.4% (101/107) had maternal IAP; 19.6% nonetheless were GBS-positive, compared with 6.5% of neonates born to noncarrier mothers (P <.01). Among neonates born to mothers receiving IAP, more were positive only at 1 month of age than at both 1 week and 1 month. The frequency of GBS in neonates born to mothers receiving IAP was significantly lower than that in neonates born to mothers not receiving IAP (P <.05). Capsular serotypes V (25%) and III (23.4%) were common, followed by Ib (15.6%), Ia (14.1%), II (7.8%), IV (6.3%), nontypeable (4.7%), and VI and VIII (each 1.6%). Conclusions Delayed colonization with GBS occurs in infants born to GBS carrier mothers receiving IAP. GBS should be considered in all infants at 1 month after birth with signs of infection.

Original languageEnglish
Pages (from-to)169-173.e1
JournalJournal of Pediatrics
Publication statusPublished - 2017 Nov 1



  • capsular serotype
  • maternal colonization
  • real-time PCR
  • Streptococcus agalactiae
  • vertical transmission

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

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