Antimicrobial Susceptibility Profiles Among Neonatal Early-onset Sepsis Pathogens.

TitleAntimicrobial Susceptibility Profiles Among Neonatal Early-onset Sepsis Pathogens.
Publication TypeJournal Article
Year of Publication2021
AuthorsFlannery DD, Puopolo KM, Hansen NI, Gerber JS, Sanchez PJ, Stoll BJ
Corporate AuthorsEunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network
JournalPediatr Infect Dis J
Date Published2021 Nov 30
ISSN1532-0987
Abstract

BACKGROUND: Empiric administration of ampicillin and gentamicin is recommended for newborns at risk of early-onset sepsis (EOS). There are limited data on antimicrobial susceptibility of all EOS pathogens.

METHODS: Retrospective review of antimicrobial susceptibility data from a prospective EOS surveillance study of infants born ≥22 weeks' gestation and cared for in Neonatal Research Network centers April 2015-March 2017. Nonsusceptible was defined as intermediate or resistant on final result.

RESULTS: We identified 239 pathogens (235 bacteria, 4 fungi) in 235 EOS cases among 217,480 live-born infants. Antimicrobial susceptibility data were available for 189/239 (79.1%) isolates. Among 81 Gram-positive isolates with ampicillin and gentamicin susceptibility data, all were susceptible in vitro to either ampicillin or gentamicin. Among Gram-negative isolates with ampicillin and gentamicin susceptibility data, 72/94 (76.6%) isolates were nonsusceptible to ampicillin, 8/94 (8.5%) were nonsusceptible to gentamicin, and 7/96 (7.3%) isolates were nonsusceptible to both. Five percent or less of tested Gram-negative isolates were nonsusceptible to each of third or fourth generation cephalosporins, piperacillin-tazobactam, and carbapenems. Overall, we estimated that 8% of EOS cases were caused by isolates nonsusceptible to both ampicillin and gentamicin; these were most likely to occur among preterm, very-low birth weight infants.

CONCLUSIONS: The vast majority of contemporary EOS pathogens are susceptible to the combination of ampicillin and gentamicin. Clinicians may consider the addition of broader-spectrum therapy among newborns at highest risk of EOS, but we caution that neither the substitution nor the addition of 1 single antimicrobial agent is likely to provide adequate empiric therapy in all cases.

DOI10.1097/INF.0000000000003380
Alternate JournalPediatr Infect Dis J
PubMed ID34862339