A Microbiologic and Clinical Description of Infant E. coli Isolates from 0 to 2 Months of Life

Abstract Corresponding Author: Mine Duzgol, MD, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone: (646)420- 9089 Sergio Lerma Narvaez, MD, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine Boston, MA 02118, USA, Sergio.Lerma [email protected], Phone: (857)294-5244 Molly Cuvellier, Pharm D1, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone: (603)702-2236 Neoreet Braha, MS 1, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone:(617)852-6666 Nhan Dinh, CRC 1, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone: (415)350-5916 Jeffrey Campbell, MD, MPH1, Section of Pediatric Infectious Diseases, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone: (617)414-5160, Sharon Vuppula, MD, Section of Pediatric Infectious Diseases, Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA, [email protected], Phone:(603) 557-2460 Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. No conflicts of interest Background Escherichia coli (E. coli) is a common cause of early-onset sepsis (EOS) in preterm infants and the second most common cause of EOS in term infants. E. coli also contributes to late-onset sepsis (LOS) and urinary tract infections (UTIs) (Shane et al., 2017; Puopolo et al., 2018; Stoll BJ, 2020). Maternal antibiotic exposure during the peripartum period may increase infant microbiome resistance. According to a large multi-site study conducted in the United States between 2009 and 2017, 10% of E. coli strains isolated in Neonatal Intensive Care Units (NICUs) were resistant to both ampicillin and gentamicin (Flannery et al 2021). Further analysis is necessary to describe the microbiological and maternal/infant demographics and antibiotic exposure during pregnancy about resistant infant E. coli isolates, which can aid in empiric antimicrobial management for infants with E. coli sepsis. Methods This study is a retrospective cross-sectional study of E. coli isolates collected at Boston Medical Center (BMC) from January 2019 to July 2023. Susceptibility patterns of E. coli isolates were determined using standard microbiologic approaches. Clinical information was retrieved from the chart review. E.coli isolates that did not have susceptibility patterns were excluded from the study. Maternal and infant clinical data points such as maternal GBS status, antenatal antibiotic exposure, and infant antibiotic exposure before positive culture were considered. Results Out of the 53 isolates, 13 (24.5%) were ampicillin and gentamicin susceptible, 27 (50%) were ampicillin non-susceptible and gentamicin susceptible, and 13 (24%) were ampicillin and gentamicin non-susceptible. Of the 42 mothers who had beta-lactam exposure during pregnancy, 21 (50%) infants had ampicillin-non-susceptible and gentamicin-susceptible isolates, and 13 (30%) had non-susceptible isolates to both ampicillin and gentamicin. Of the 18 infants with beta-lactam exposure before developing an E.coli infection, 9 (50%) had infants with ampicillin non-susceptible and gentamicin-susceptible isolates, and 8 (44%) had isolates that were non-susceptible to ampicillin and gentamicin. Of the 16 infants who had gentamicin exposure before a positive culture, 7(43%) had ampicillin non-susceptible and gentamicin susceptible isolates, and 8 (50%) had Ampicillin and Gentamicin non-susceptible isolates. Conclusion We identified relatively high rates of ampicillin and gentamicin non-susceptibility among E. coli isolated from neonates at our institution. Rates of non-susceptibility to ampicillin and gentamicin were particularly high when infant beta-lactam and gentamicin exposure occurred before a positive culture. A multicenter study that evaluates maternal and neonatal treatment prior to E. coli isolation would be valuable to guide antenatal and postnatal antibiotic stewardship initiatives. Figure 1: Neonatal B-lactam Antibiotic exposure prior to positive culture (n=18) Figure 2: Infant ampicillin and gentamicin susceptibility based on maternal antimicrobial exposure. AG: Aminoglycoside References 1. Shane AL, Sánchez PJ, Stoll BJ. Neonatal sepsis. Lancet. 2017 Oct 14;390(10104):1770-1780. doi: 10.1016/S0140-6736(17)31002-4. Epub 2017 Apr 20 2. Puopolo KM, Benitz WE, Zaoutis TE; Committee on Fetus and Newborn; Committee on Infectious Diseases. Management of neonates born at ≤34 6/7 weeks’ gestation with suspected or proven early-onset bacterial sepsis. Pediatrics. 2018;142(6) 3. Stoll BJ, Puopolo KM, Hansen NI, Sánchez PJ, Bell EF, Carlo WA, Cotten CM, D’Angio CT, Kazzi SNJ, Poindexter BB, Van Meurs KP, Hale EC, Collins MV, Das A, Baker CJ, Wyckoff MH, Yoder BA, Watterberg KL, Walsh MC, Devaskar U, Laptook AR, Sokol GM, Schrag SJ, Higgins RD; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Early-Onset Neonatal Sepsis 2015 to 2017, the Rise of Escherichia coli, and the Need for Novel Prevention Strategies. JAMA Pediatr. 2020 Jul 1;174(7) 4. Flannery D. D., Akinboyo I. C., Mukhopadhyay S., Tribble A. C., Song L., Chen F., et al. (2021). Antibiotic susceptibility of escherichia coli among infants admitted to neonatal intensive care units across the US from 2009 to 2017. JAMA Pediatr. 175, 168–175.