Fighting Antimicrobial Resistance in Neonatal Intensive Care Units: Rational Use of Antibiotics in Neonatal Sepsis

Associations between maternal bacteremia during the peripartum period and early-onset neonatal sepsis: a retrospective cohort study

INTRODUCTION

Early-onset neonatal sepsis (EONS) significantly impacts neonatal morbidity and mortality, with maternal bacteremia during the peripartum period being a potential risk factor. This study aims to explore the association between peripartum maternal bacteremia and EONS.

METHODS

A retrospective cohort study at the Women's Wellness and Research Center in Doha, Qatar (2015-2019) compared women with and without bacteremia, based on blood cultures taken from up to seven days before to 48 h after delivery, examining the association with EONS.

RESULTS

Among the 536 maternal blood cultures analyzed, 102 (19.0%) were positive. The most prevalent organisms were Group B streptococcus (GBS) (39.2%), followed by Escherichia coli (14.7%) and anaerobes (10.8%). Neonates from bacteremic mothers had lower birth weights (2913 ± 86 g vs. 3140 ± 745 g; MD 227.63 g; 95% CI 61.72 - 393.55; p = 0.007), required more resuscitation (27.5% vs. 13.2%; OR 2.48; 95% CI 1.48 - 4.17; p < 0.001), and received antibiotics for ≥ 7 days more frequently (41.2% vs. 16.6%; OR 3.51; 95% CI 2.20 - 5.62; p < 0.001) compared to those from non-bacteremic mothers. Maternal Gram-positive (GP) organisms were more commonly isolated in term gestation (67.9%) compared to Gram-negative (GN) (22.2%) and anaerobic bacteremias (9.9%). During intrapartum, GP bacteremia was predominant (67.1%) vs. GN (21.4%) and Anaerobes (11.4%), with GN bacteremia being more common in postpartum samples. Culture-proven EONS occurred in 0.75% of the cohort, affecting 3.9% of infants from bacteremic mothers vs. none in controls (OR 2.34; 95% CI 1.27 - 4.31; p < 0.001). Culture-negative EONS appeared in 14.7% of infants from bacteremic mothers vs. 7.8% in controls (OR 2.02; 95% CI, 1.05 - 3.88; p = 0.03). Among 40 cases of maternal GBS bacteremia, culture-proven GBS EONS occurred in 3 neonates (7.5%), all from mothers with negative GBS screening, compared to none in the control group. A strong association was found between EONS and maternal bacteremia due to any organism (aOR 2.34; 95% CI, 1.24 - 4.41; p = 0.009), GP bacteremia (aOR 3.66; 95% CI, 1.82 - 7.34; p < 0.001), or GBS (aOR 5.74; 95% CI, 2.57 - 12.81; p < 0.001). Bacteremia due to GN and Anaerobic organisms were not associated with EONS. Chorioamnionitis and antepartum fever were independent predictors for EONS associated with significant bacterial isolates.

CONCLUSION

This study underscores the significant impact of maternal GP bacteremia, particularly from GBS, on EONS. The strong association highlights the need for vigilant monitoring and interventions in pregnancies complicated by bacteremia to reduce adverse neonatal outcomes.

Efficacy of Antibiotic Regimens for Meningitis in Young Infants Aged 0-59 Days: A Systematic Review

CONTEXT

Meningitis is associated with high mortality risk in young infants, yet the optimal treatment regimen is unclear.

OBJECTIVES

To systematically evaluate the efficacy of antibiotic regimens to treat meningitis in young infants aged 0 to 59 days on critical clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, WHO Global Index Medicus, and Cochrane Central Registry of Trials.

STUDY SELECTION

We included randomized controlled trials (RCTs) of young infants with meningitis (population) comparing the efficacy of antibiotic regimens (interventions) with alternate regimens (control) on clinical outcomes.

DATA EXTRACTION

We extracted data on study characteristics and assessed risk of bias in duplicate. Grading of Recommendations Assessment, Development, and Evaluation was used to assess certainty of evidence.

RESULTS

Of 1088 studies screened, only 2 RCTs were identified. They included 168 infants from 5 countries and were conducted between 1976 and 2015. Neither study compared current World Health Organization-recommended regimens. One multisite trial from 4 countries compared intrathecal gentamicin plus systemic ampicillin/gentamicin to systemic ampicillin/gentamicin and found no difference in mortality (relative risk, 0.88; 95% confidence interval, 0.41-1.53; 1 trial, n = 98, very low certainty of evidence) or adverse events (no events in either trial arm). Another trial in India compared a 10-day versus 14-day course of antibiotics and found no difference in mortality (relative risk, 0.88; 95% confidence interval, 0.41-1.53; 1 trial, n = 98, very low certainty of evidence) or other outcomes.

CONCLUSIONS

Trial data on the efficacy of antibiotic regimens in young infant meningitis are scarce. Rigorous RCTs are needed to inform recommendations for optimal antibiotic regimens for meningitis treatment in this vulnerable population, particularly within the context of changing epidemiology and increasing antimicrobial resistance.

External Evaluation of Population Pharmacokinetic Models of Piperacillin in Preterm and Term Patients from Neonatal Intensive Care

BACKGROUND AND OBJECTIVES

Piperacillin/tazobactam is extensively used off-label to treat late-onset neonatal sepsis, but safety and pharmacokinetic data in this population are limited. Additionally, the organic immaturity of the newborns contributes to a high piperacillin pharmacokinetic variability. This affects the clinical efficacy of the antibiotic treatment and increases the probability of developing drug resistance. This study aimed to evaluate the predictive performance of reported piperacillin population pharmacokinetic models for their application in a model-informed precision dosing strategy in preterm and term Mexican neonatal intensive care patients.

METHODS

Published population pharmacokinetic models for piperacillin which included neonates in their study population were identified. From the reference models, structured models, population pharmacokinetic parameters, and interindividual and residual variability data were extracted to be replicated in pharmacokinetic software (NONMEM® version 7.4). For the clinical study, a sampling schedule was designed, and 2-3 blood samples of 250 µL were taken from neonates who met the inclusion criteria. Piperacillin plasma concentrations were determined by liquid chromatography/tandem mass spectrometry. The clinical treatment data were collected, and piperacillin plasma concentrations were estimated using reference pharmacokinetic models for an a priori or Bayesian approach. Statistical methods were used in terms of bias and precision to evaluate the differences between observed and estimated neonatal piperacillin plasma concentrations with the different approaches and to identify the pharmacokinetic model that best fits the neonatal data.

RESULTS

A total of 70 plasma samples were collected from 25 neonatal patients, of which 15 were preterm neonates. The overall median value (range) postnatal age, gestational age, body weight, and serum creatinine at the sampling collecting day were 12 (3-26) days, 34.2 (26-41.1) weeks, 1.78 (0.08-3.90) Kg, 0.47 (0.20-0.90) mg/dL, respectively. Three population pharmacokinetic models for piperacillin in infants up to 2 months were identified, and their predictive performance in neonatal data was evaluated. No pharmacokinetic model was suitable for our population using an a priori approach. The model published by Cohen-Wolkowiez et al. in 2014 with a Bayesian approach showed the best performance of the pharmacokinetic models evaluated in our neonatal data. The procedure requires two blood samples (predose and postdose), and, when applied, it predicted 66.6% of the observations with a relative median absolute predicted error of less than 30%.

CONCLUSIONS

The population pharmacokinetic model developed by Cohen-Wolkowiez et al. in 2014 demonstrated superior performance in predicting the plasma concentration of piperacillin in preterm and term Mexican neonatal intensive care patients. The Bayesian approach, including two different piperacillin plasma concentrations, was clinically acceptable regarding bias and precision. Its application for model-informed precision dosing can be an option to optimize the piperacillin dosage in our population.

Neonatal Sepsis Due to Multidrug-resistant Bacteria at a Tertiary Teaching Hospital in Ethiopia

BACKGROUND

The burden of multidrug-resistant bacterial infections in low-income countries is alarming. This study aimed to identify the bacterial etiologies and antibiotic resistance patterns among neonates in Jimma, Ethiopia.

METHODS

An observational longitudinal study was conducted among 238 presumptive neonatal sepsis cases tested with blood and/or cerebrospinal fluid culture. The bacterial etiologies were confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The antibiotic resistance patterns were determined using the automated disc diffusion method (Bio-Rad) and the results were interpreted based on the European Committee on Antimicrobial Susceptibility Testing 2021 breakpoints. Extended-spectrum β-lactamases were detected using a double disc synergy test and confirmed by Mast discs (Mast Diagnostica GmbH).

RESULTS

A total of 152 pathogens were identified. Of these, Staphylococcus aureus (18.4%) was the predominant isolate followed by Klebsiella pneumoniae (15.1%) and Escherichia coli (10.5%). All the isolates exhibited a high rate of resistance to first- and second-line antibiotics ranging from 73.3% for gentamicin to 93.3% for ampicillin. Furthermore, 74.4% of the Gram-negative isolates were extended-spectrum β-lactamase producers and 57.1% of S. aureus strains were methicillin resistant. The case fatality rate was 10.1% and 66.7% of the deaths were attributable to infections by multidrug-resistant pathogens.

CONCLUSIONS

The study revealed a high rate of infections with multidrug-resistant pathogens. This poses a significant challenge to the current global and national target to reduce neonatal mortality rates. To address these challenges, it is important to employ robust infection prevention practices and continuous antibiotic resistance testing to allow targeted therapy.

Machine Learning: A Potential Therapeutic Tool to Facilitate Neonatal Therapeutic Decision Making

Bacterial infection is one of the major causes of neonatal morbidity and mortality worldwide. Finding rapid and reliable methods for early recognition and diagnosis of bacterial infections and early individualization of antibacterial drug administration are essential to eradicate these infections and prevent serious complications. However, this is often difficult to perform due to non-specific clinical presentations, low accuracy of current diagnostic methods, and limited knowledge of neonatal pharmacokinetics. Although neonatal medicine has been relatively late to embrace the benefits of machine learning (ML), there have been some initial applications of ML for the early prediction of neonatal sepsis and individualization of antibiotics. This article provides a brief introduction to ML and discusses the current state of the art in diagnosing and treating neonatal bacterial infections, gaps, potential uses of ML, and future directions to address the limitations of current studies. Neonatal bacterial infections involve a combination of physiologic development, disease expression, and treatment response outcomes. To address this complex relationship, future models could consider appropriate ML algorithms to capture time series features while integrating influences from the host, microbes, and drugs to optimize antimicrobial drug use in neonates. All models require prospective clinical trials to validate their clinical utility before clinical use.

High prevalence of multidrug-resistant Enterobacterales carrying extended-spectrum beta-lactamase and AmpC genes isolated from neonatal sepsis in Ahvaz, Iran

OBJECTIVES

In the recent years, multidrug resistant (MDR) neonatal septicemia-causing Enterobacterales has been dramatically increased due to the extended-spectrum beta-lactamases (ESBLs) and AmpC enzymes. This study aimed to assess the antibiotic resistance pattern, prevalence of ESBLs/AmpC beta-lactamase genes, and Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) fingerprints in Enterobacterales isolated from neonatal sepsis.

RESULTS

In total, 59 Enterobacterales isolates including 41 (69.5%) Enterobacter species, 15 (25.4%) Klebsiella pneumoniae and 3 (5.1%) Escherichia coli were isolated respectively. Resistance to ceftazidime and cefotaxime was seen in all of isolates. Furthermore, all of them were multidrug-resistant (resistant to three different antibiotic categories). The phenotypic tests showed that 100% of isolates were ESBL-positive. Moreover, AmpC production was observed in 84.7% (n = 50/59) of isolates. Among 59 ESBL-positive isolates, the highest percentage belonged to blaCTX-M-15 gene (66.1%) followed by blaCTX-M (45.8%), blaCTX-M-14 (30.5%), blaSHV (28.8%), and blaTEM (13.6%). The frequency of blaDHA, blaEBC, blaMOX and blaCIT genes were 24%, 24%, 4%, and 2% respectively. ERIC-PCR analysis revealed that Enterobacterales isolates were genetically diverse. The remarkable prevalence of MDR Enterobacterales isolates carrying ESBL and AmpC beta-lactamase genes emphasizes that efficient surveillance measures are essential to avoid the more expansion of drug resistance amongst isolates.

Umbilical cord blood culture for early onset sepsis in preterm infants

BACKGROUND

Umbilical cord blood culture (UCBC) may have a diagnostic utility for early onset sepsis (EOS) detection in preterm infants. It may prevent sampling the newborn and collect a higher volume of blood for pathogenic identification.

METHODS

Retrospective analysis at a tertiary care center in Canada of preterm infants ≤ 34 0/7 weeks' gestation with UCBC taken at birth.

RESULTS

Of 505 admitted infants, 195 had UCBC. 170 UCBCs were negative; 44 of these had also negative neonatal blood culture (NBC). No infants with negative UCBC showed EOS symptoms in the first week of life. 25 UCBCs were positive: 18 were contaminants (all with negative NBC) and 7 were confirmed as EOS. 18 infants with UCBC contaminants remained asymptomatic. 7 EOS cases were identified, with varying bacteriological profiles; 5 displayed sepsis symptoms while 2 were asymptomatic. Risk of EOS increased with prolonged rupture of membranes.

CONCLUSIONS

UCBC effectively detected EOS establishing it as a method with possibly better diagnostic performance than NBC in high-risk neonates. Further studies are needed to improve UCBC technique and lower contamination rates.

IMPACT

Umbilical cord blood culture has a higher bacterial identification rate than peripheral venous blood culture for the early identification of early-onset sepsis in preterm infants. Umbilical cord blood cultures that showed no growth were reliable predictors of not developing early onset sepsis. Umbilical cord blood culture should be considered as part of the evaluation for early onset sepsis in the preterm infants.

Risk factors of multidrug-resistant organisms neonatal sepsis in Surabaya tertiary referral hospital: a single-center study

BACKGROUND

Bacterial organisms causing neonatal sepsis have developed increased resistance to commonly used antibiotics. Antimicrobial resistance is a major global health problem. The spread of Multidrug-Resistant Organisms (MDROs) is associated with higher morbidity and mortality rates. This study aimed to determine the risk factors for developing MDRO neonatal sepsis in the Neonatal Intensive Care Unit (NICU), dr. Ramelan Navy Central Hospital, in 2020-2022.

METHODS

A cross-sectional study was performed on 113 eligible neonates. Patients whose blood cultures were positive for bacterial growth and diagnosed with sepsis were selected as the study sample. Univariate and multivariate analysis with multiple logistic regression were performed to find the associated risk factors for developing multidrug-resistant organism neonatal sepsis. A p-value of < 0.05 was considered significant.

RESULTS

Multidrug-resistant organisms were the predominant aetiology of neonatal sepsis (91/113, 80.5%). The significant risk factors for developing MDRO neonatal sepsis were lower birth weight (OR: 1.607, 95% CI: 1.003 - 2.576, p-value: 0.049), history of premature rupture of the membrane (ProM) ≥ 18 (OR: 3.333, 95% CI: 2.047 - 5.428, p-value < 0.001), meconium-stained amniotic fluid (OR: 2.37, 95% CI: 1.512 - 3.717, p-value < 0.001), longer hospital stays (OR: 5.067, 95% CI: 2.912 - 8.815, p-value < 0.001), lower Apgar scores (OR: 2.25, 95% CI: 1.442 - 3.512, p-value < 0.001), and the use of respiratory support devices, such as invasive ventilation (OR: 2.687, 95% CI: 1.514 - 4.771, p-value < 0.001), and non-invasive ventilation (OR: 2, 95% CI: 1.097 - 3.645, p-value: 0.024).

CONCLUSIONS

Our study determined various risk factors for multidrug-resistance organism neonatal sepsis and underscored the need to improve infection control practices to reduce the existing burden of drug-resistant sepsis. Low-birth-weight, a maternal history of premature rupture of the membrane lasting more than 18 hours, meconium-stained amniotic fluid, longer hospital stays, a low Apgar score, and the use of ventilators were the risk factors for developing drug-resistant neonatal sepsis.

Pharmacokinetic and Pharmacodynamic Considerations of Antibiotic Use in Neonates

The selection of an appropriate dose of a given antibiotic for a neonate not only requires knowledge of the drug's basic pharmacokinetic (PK) and pharmacodynamic (PD) properties but also the profound effects that organ development might have on the volume of distribution and clearance, both of which may affect the PK/PD of a drug. Interest has grown in alternative antibiotic dosing strategies that are better aligned with the antibiotic's PK and PD properties. These strategies should be used in conjunction with minimum inhibitory concentration measurements and therapeutic drug monitoring to measure their potential success. They can also guide the clinician in tailoring the delivery of antibiotics to suit an individual patient's needs. Model-informed precision dosing, such as Bayesian forecasting dosing software (which incorporates PK/PD population models), may be utilized to optimize antibiotic exposure in neonatal populations. Consequently, optimizing the antibiotic dose and exposure in each newborn requires expertise in different fields. It drives the collaboration of physicians together with lab technicians and quantitative clinical pharmacologists.

Duration of Neonatal Antibiotic Exposure in Preterm Infants in Association with Health and Developmental Outcomes in Early Childhood

Over 90% of preterm neonates are, often empirically, exposed to antibiotics as a potentially life-saving measure against sepsis. Long-term outcome in association with antibiotic exposure (NABE) has insufficiently been studied after preterm birth. We investigated the association of NABE-duration with early-childhood developmental and health outcomes in preterm-born children and additionally assessed the impact of GA on outcomes. Preterm children (GA < 30 weeks) participating in a multicenter cohort study were approached for follow-up. General expert-reviewed health questionnaires on respiratory, atopic and gastrointestinal symptoms were sent to parents of children > 24 months' corrected age (CA). Growth and developmental assessments (Bayley Scales of Infant and Toddler Development (BSID) III) were part of standard care assessment at 24 months' CA. Uni- and multivariate regressions were performed with NABE (per 5 days) and GA (per week) as independent variables. Odds ratios (OR) for health outcomes were adjusted (aOR) for confounders, where appropriate. Of 1079 infants whose parents were approached, 347 (32%) responded at a mean age of 4.6 years (SD 0.9). In children with NABE (97%), NABE duration decreased by 1.6 days (p < 0.001) per week of gestation. Below-average gross-motor development (BSID-III gross-motor score < 8) was associated with duration of NABE (aOR = 1.28; p = 0.04). The aOR for constipation was 0.81 (p = 0.04) per gestational week. Growth was inversely correlated with GA. Respiratory and atopic symptoms were not associated with NABE, nor GA. We observed that prolonged NABE after preterm birth was associated with below-average gross-motor development at 24 months' CA, while a low GA was associated with lower weight and stature Z-scores and higher odds for constipation.