Escherichia coli Is Overtaking Group B Streptococcus in Early-Onset Neonatal Sepsis

Predictive factors for perinatal bacterial transmission from colonized mothers to delivered very-low-birth-weight infants: a retrospective cohort study

This study investigated the predictive factors for perinatal bacterial transmission in very-low-birth-weight infants (VLBWIs) born to mothers with a history of intrapartum colonization. We retrospectively reviewed the medical records of 173 VLBWIs, wherein pathogens were confirmed in maternal cultures obtained from the blood, urine, and vagina during the intrapartum period from 2013 to 2020. Newborns were categorized based on microbiological tests, including gastric aspirates, endotracheal aspirates, blood, and skin/nasal swab cultures collected immediately after birth. Infants whose cultures matched their maternal pathogens were categorized into the "transmission group" (n = 45), while those who tested negative were assigned to the "control group" (n = 128). The predominant maternal-colonizing pathogen observed was Escherichia coli (30.6%), which also emerged as the primary colonizing pathogen in neonates (35.6%). Transmission group had higher incidences of maternal leukocytosis, chorioamnionitis, and cervical cerclage. Regarding neonatal characteristics, the transmission group demonstrated lower initial base excesses (- 6.3 ± 3.9 vs. - 9.2 ± 4.9, P < 0.05) and higher C-reactive protein levels (0.1 ± 0.3 vs. 0.4 ± 0.8, P < 0.05). Notably, regarding major neonatal outcomes, transmission group had higher mortality rates and incidences of severe intraventricular hemorrhage. These findings may be useful for making decisions when considering antibiotic treatment for infants with a history of maternal colonization.

High Incidence Rates of Early-onset Bacterial Sepsis in Infants Born in Two Brazilian Maternities: A 15-Year Retrospective Analysis

BACKGROUND

Data on the burden and etiology of neonatal early-onset bacterial sepsis (EOBS) in low-to-middle-income countries are scarce. Surveillance is critical for optimizing prevention and treatment strategies. We aimed to estimate the incidence of EOBS in 2 large Brazilian cohorts of neonates.

METHODS

Data were retrospectively obtained from 33,794 neonates born between 2009 and 2017 at low-risk (n = 17,981) and high-risk maternity centers (n = 15,813). Blood cultures were taken within 72 hours of life from neonates with perinatal risk factors for EOBS or suspected EOBS. A positive blood culture for a pathogenic microorganism and a compatible clinical evolution confirmed the diagnosis of EOBS.

RESULTS

One-third of the infants born from high-risk and 18.5% from low-risk maternities were investigated for EOBS. Overall, EOBS was more incident in neonates born in the high-risk facilities [66 cases or 4.2/1000 (95% CI: 3.2-5.3)] than in the low-risk facilities [24 cases or 1.3/1000 (95% CI: 0.9-2.0)]. The incidence rate of EOBS increased with decreasing gestational age (<32 weeks: 20.5/1000; 32-36 weeks: 5.6/1000; ≥37 weeks: 1.5/1000). Group B Streptococcus (GBS) was the agent more frequently identified in high-risk and low-risk maternities: 1.8/1000 (95% CI: 1.1-2.4) and 0.4/1000 (95% CI: 0.2-0.9), respectively. EOBS's overall case fatality rate was 17.8% for all the agents and 22% for GBS.

CONCLUSIONS

EOBS remains unacceptably high and is frequently fatal in preterm and term infants cared for in high- or low-risk maternities. Because GBS has emerged as the most frequent causative agent, preventive strategies are urgently needed.

Early-Onset Infection Caused by Escherichia coli Sequence Type 1193 in Late Preterm and Full-Term Neonates

Using whole-genome sequencing, we characterized Escherichia coli strains causing early-onset sepsis (EOS) in 32 neonatal cases from a 2019-2021 prospective multicenter study in France and compared them to E. coli strains collected from vaginal swab specimens from women in third-trimester gestation. We observed no major differences in phylogenetic groups or virulence profiles between the 2 collections. However, sequence type (ST) analysis showed the presence of 6/32 (19%) ST1193 strains causing EOS, the same frequency as in the highly virulent clonal group ST95. Three ST1193 strains caused meningitis, and 3 harbored extended-spectrum β-lactamase. No ST1193 strains were isolated from vaginal swab specimens. Emerging ST1193 appears to be highly prevalent, virulent, and antimicrobial resistant in neonates. However, the physiopathology of EOS caused by ST1193 has not yet been elucidated. Clinicians should be aware of the possible presence of E. coli ST1193 in prenatal and neonatal contexts and provide appropriate monitoring and treatment.

Epidemiologic Changes of Neonatal Early-onset Sepsis After the Implementation of Universal Maternal Screening for Group B Streptococcus in Hong Kong

BACKGROUND

The epidemiology of neonatal early-onset sepsis (EOS) has changed with time and with changes in prevention strategy. Population-representative contemporary data provide insights on how to further improve EOS prevention and triage strategies.

METHODS

Neonates born in public hospitals in Hong Kong from January 1, 2006, to December 31, 2017 were included. The epidemiological characteristics of EOS and the use of intrapartum antibiotic prophylaxis (IAP) were compared between the 2 epochs before (January 1, 2006 to December 31, 2011) and after (January 1, 2012 to December 31, 2017) the territory-wide implementation of universal maternal group B Streptococcus (GBS) screening.

RESULTS

EOS developed in 1.07‰ of live births (522/490,034). After the implementation of universal GBS screening, the EOS rate decreased in neonates born ≥34 weeks (1.17‰-0.56‰, P < 0.001) and remained similar in those born <34 weeks (7.8‰-10.9‰, P = 0.15), whereas the proportions of IAP coverage increased in both groups [7.6%-23.3% ( P < 0.001) and 28.5%-52.0% ( P < 0.001), respectively]. The major pathogen for EOS shifted from GBS to Escherichia coli , and for early-onset meningitis from GBS to Streptococcus bovis . IAP was associated with subsequent isolation of pathogens resistant to ampicillin [adjusted odds ratio (aOR) 2.3; 95% confidence interval (CI): 1.3-4.2], and second-generation [aOR 2.0; 95% CI: 1.02-4.3] and third-generation [aOR 2.2; 95% CI: 1.1-5.0] cephalosporins.

CONCLUSIONS

Pathogen profile of EOS changed with the implementation of universal GBS screening. S. bovis has emerged as a more common pathogen associated with the risk of meningitis. IAP may not be as effective in reducing EOS rate among infants born <34 weeks as compared with those ≥34 weeks, and newer strategies may be needed.

Lumbar Puncture and Meningitis in Infants with Proven Early- or Late-Onset Sepsis: An Italian Prospective Multicenter Observational Study

Background: To evaluate the rates of lumbar puncture (LP) in infants with culture-proven sepsis. Study design: We prospectively enrolled 400 infants with early- or late-onset sepsis due to Group B streptococcus (GBS) or Eschericha coli, diagnosed within 90 days of life. Rates of LP and potential variables associated with LP performance were evaluated. Moreover, cerebrospinal fluid (CSF) characteristics and results of the molecular analysis were investigated. Results: LP was performed in 228/400 (57.0%) infants; 123/228 LPs (53.9%) were performed after antibiotic initiation, hampering the ability to identify the pathogen in the CSF culture. However, polymerase chain reaction increased the probability of positive results of CSF analysis compared to microbiological culture (28/79, 35.4% vs. 14/79, 17.7%, p = 0.001). Severe clinical presentation and GBS infection were associated with higher LP rates. The rate of meningitis was 28.5% (65/228). Conclusions: Rates of LP are low in culture-proven neonatal sepsis and antibiotics are frequently given before LP is carried out. Thus meningitis may be underestimated, and the chances of giving an effective therapy to the newborn are reduced. LP should be performed before the start of antibiotics when there is a clinical suspicion of infection.

Timing of Symptoms of Early-Onset Sepsis after Intrapartum Antibiotic Prophylaxis: Can It Inform the Neonatal Management?

The effectiveness of "inadequate" intrapartum antibiotic prophylaxis (IAP administered < 4 h prior to delivery) in preventing early-onset sepsis (EOS) is debated. Italian prospective surveillance cohort data (2003-2022) were used to study the type and duration of IAP according to the timing of symptoms onset of group B streptococcus (GBS) and E. coli culture-confirmed EOS cases. IAP was defined "active" when the pathogen yielded in cultures was susceptible. We identified 263 EOS cases (GBS = 191; E. coli = 72). Among GBS EOS, 25% had received IAP (always active when beta-lactams were administered). Most IAP-exposed neonates with GBS were symptomatic at birth (67%) or remained asymptomatic (25%), regardless of IAP duration. Among E. coli EOS, 60% were IAP-exposed. However, IAP was active in only 8% of cases, and these newborns remained asymptomatic or presented with symptoms prior to 6 h of life. In contrast, most newborns exposed to an "inactive" IAP (52%) developed symptoms from 1 to >48 h of life. The key element to define IAP "adequate" seems the pathogen's antimicrobial susceptibility rather than its duration. Newborns exposed to an active antimicrobial (as frequently occurs with GBS infections), who remain asymptomatic in the first 6 h of life, are likely uninfected. Because E. coli isolates are often unsusceptible to beta-lactam antibiotics, IAP-exposed neonates frequently develop symptoms of EOS after birth, up to 48 h of life and beyond.