Neonatal sepsis: an old problem with new insights

Role of the Microbiome in Neonatal Infection: Pathogenesis and Implications for Management

The human microbiome refers to the collective genome of microorganisms, including bacteria, fungi, and viruses residing on human body surfaces that are in contact with the environment. Together these communities protect against invasive infections. Conversely, when disrupted, the microbiome can be the source of pathogens causing invasive infection. Interventions to manipulate it via probiotics, antibiotics, and fecal transplantation are available. The risk benefit of these interventions remains unclear. In this review, the authors discuss evidence linking the gut microbiome to neonatal sepsis and also discuss the challenges for translating this knowledge into better clinical care.

Lipopolysaccharide induced systemic inflammation and heart rate variability in a term newborn piglet model

BACKGROUND

Early biomarkers are needed to improve diagnosis and support antibiotic stewardship in neonatal sepsis. Heart rate variability (HRV) is proposed as such a biomarker. However, there is a lack of studies in term newborns. Infusion of lipopolysaccharide (LPS) from Escherichia coli induces systemic inflammation comparable to sepsis in newborns. We aimed to study the effect of systemic LPS induced inflammation on HRV in term newborn piglets.

METHODS

Baseline HRV was recorded for 1 h. This control period was compared to the hourly HRV for each piglet (n = 9) during 4 h of LPS infusion. For comparison, we used a mixed-effects regression model.

RESULTS

Systemic inflammation induced by LPS was found to reduce HRV. Compared to baseline, most measures of HRV decreased to lower values compared to baseline at 2 h, 3 h, and 4 h after initiation of LPS infusion. Heart rate (HR) was increased at 2 h, 3 h, and 4 h. When adjusting for HR in the mixed-effects regression model all reductions in HRV were explained by the increase in HR.

CONCLUSIONS

Reduced HRV may be an early biomarker of neonatal sepsis. However, an increase in HR alone could be an already available, more accessible, and interpretable biomarker of sepsis in term neonates.

IMPACT

In a term newborn piglet model, systemic inflammation induced by lipopolysaccharide from Escherichia coli reduced heart rate variability measures and increased heart rate. All reductions in heart rate variability were mediated by heart rate. While heart rate variability may be a biomarker of sepsis in term newborns, changes in heart rate alone could be a more readily available biomarker.

Impact of neonatal sepsis on serum selenium levels: Evidence of decreased selenium in sepsis-affected neonates

Introduction

Essential trace elements and micronutrients are critical in eliciting an effective immune response to combat sepsis, with selenium being particularly noteworthy. The objective of this investigation is to analyze and the levels of serum selenium in neonates within sepsis and control groups.

Methodology

In 2023, a case-control study was carried out involving 66 hospitalized infants - 33 diagnosed with sepsis forming the case group and 33 free from sepsis constituting the control group - along with their mothers, at Children's and Shariati Hospitals in Bandar Abbas. The serum selenium concentrations (expressed in micrograms per deciliter) were quantified utilizing atomic absorption spectrometry. Subsequently, the data were processed and analyzed using IBM SPSS statistical software, version 22.

Results

The average serum selenium level in neonates with sepsis (42.06 ± 20.40 µg/dL) was notably lower compared to the control group (55.61 ± 20.33 µg/dL), a difference that was statistically significant (p-value = 0.009). The levels of serum selenium were comparable between neonates and mothers across both study groups.

Conclusion

The findings of this research indicate that selenium levels in the sepsis group were reduced compared to the control group, despite similar selenium levels in the mothers and neonates in both groups, suggesting that sepsis could be associated with a decrease in selenium levels.

Increased antibiotic resistance in preterm neonates under early antibiotic use

The standard use of antibiotics in newborns to empirically treat early-onset sepsis can adversely affect the neonatal gut microbiome, with potential long-term health impacts. Research into the escalating issue of antimicrobial resistance in preterm infants and antibiotic practices in neonatal intensive care units is limited. A deeper understanding of the effects of early antibiotic intervention on antibiotic resistance in preterm infants is crucial. This retrospective study employed metagenomic sequencing to evaluate antibiotic resistance genes (ARGs) in the meconium and subsequent stool samples of preterm infants enrolled in the Routine Early Antibiotic Use in Symptomatic Preterm Neonates study. Microbial metagenomics was conducted using a subset of fecal samples from 30 preterm infants for taxonomic profiling and ARG identification. All preterm infants exhibited ARGs, with 175 unique ARGs identified, predominantly associated with beta-lactam, tetracycline, and aminoglycoside resistance. Notably, 23% of ARGs was found in preterm infants without direct or intrapartum antibiotic exposure. Post-natal antibiotic exposure increases beta-lactam/tetracycline resistance while altering mechanisms that aid bacteria in withstanding antibiotic pressure. Microbial profiling revealed 774 bacterial species, with antibiotic-naive infants showing higher alpha diversity (P = 0.005) in their microbiota and resistome compared with treated infants, suggesting a more complex ecosystem. High ARG prevalence in preterm infants was observed irrespective of direct antibiotic exposure and intensifies with age. Prolonged membrane ruptures and maternal antibiotic use during gestation and delivery are linked to alterations in the preterm infant resistome and microbiome, which are pivotal in shaping the ARG profiles in the neonatal gut.This study is registered with ClinicalTrials.gov as NCT02784821.

IMPORTANCE

A high burden of antibiotic resistance in preterm infants poses significant challenges to neonatal health. The presence of antibiotic resistance genes, along with alterations in signaling, energy production, and metabolic mechanisms, complicates treatment strategies for preterm infants, heightening the risk of ineffective therapy and exacerbating outcomes for these vulnerable neonates. Despite not receiving direct antibiotic treatment, preterm infants exhibit a concerning prevalence of antibiotic-resistant bacteria. This underscores the complex interplay of broader influences, including maternal antibiotic exposure during and beyond pregnancy and gestational complications like prolonged membrane ruptures. Urgent action, including cautious antibiotic practices and enhanced antenatal care, is imperative to protect neonatal health and counter the escalating threat of antimicrobial resistance in this vulnerable population.

Understanding the Difficulties in Diagnosing Neonatal Sepsis: Assessing the Role of Sepsis Biomarkers

Background

Neonatal sepsis is a serious condition with high rates of morbidity and mortality, caused by the rapid growth of microorganisms that trigger a systemic reaction. Symptoms can range from mild to severe presentations. The causative microorganism is usually transmitted from mothers, especially from the urogenital tract, or can originate from the community or hospital.

Methods

Our retrospective study assessed 121 newborns, including both preterm and term infants, divided into three groups within the first 28 days of life: early-onset sepsis (35), late-onset sepsis (39), and a control group (47). Blood samples and cultures were obtained upon admission or at the onset of sepsis (at 24 and 72 hours). The study aimed to evaluate the limitations of commonly used biomarkers and new markers such as lactate dehydrogenase and ferritin in more accurately diagnosing neonatal sepsis.

Results

Our study revealed a significant difference between the initial and final measures of lactate dehydrogenase (LDH) and ferritin in the early-onset sepsis (EOS) and late-onset sepsis (LOS) groups.

Conclusion

Ferritin and LDH may serve as potential markers associated with systemic response and sepsis in cases of both early and late-onset sepsis. Monitoring these biomarkers can aid in the timely detection and management of sepsis, potentially improving patient outcomes.

Risk factors for necrotizing enterocolitis in small-for-gestational-age infants: a matched case-control study

Few studies have focused on the risk factors for necrotizing enterocolitis (NEC) in small for gestational age (SGA) infants. The aim of this study was to identify the risk factors for NEC in SGA newborns. This study included consecutive SGA neonates admitted to a tertiary hospital in Jiangxi Province, China from Jan 2008 to Dec 2022. Patients with NEC (Bell's stage ≥ II) were assigned to the NEC group. Gestational age- and birth weight-matched non-NEC infants born during the same period at the same hospital were assigned to the control group. The risk factors associated with NEC were analyzed with univariate and logistic regression models. During the study period, 2,912 SGA infants were enrolled, 150 (5.15%) of whom developed NEC. In total, 143 patients and 143 controls were included in the NEC and control groups, respectively. Logistic regression analysis revealed that sepsis (OR 2.399, 95% CI 1.271-4.527, P = 0.007) and anemia (OR 2.214, 95% CI 1.166-4.204, P = 0.015) might increase the incidence of NEC in SGA infants and that prophylactic administration of probiotics (OR 0.492, 95% CI 0.303-0.799, P = 0.004) was a protective factor against NEC. Therefore, sepsis, anemia and a lack of probiotic use are independent risk factors for NEC in SGA infants.

Role of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in diagnosing neonatal sepsis

Clinical manifestations of neonatal sepsis are often unspecified. Therefore, sepsis biomarkers could be used to support diagnosis while waiting for blood culture results, such as the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). The aim of this study was to evaluate the role of NLR and PLR as diagnostic markers in neonatal sepsis. A cross-sectional study was conducted at Haji Adam Malik General Hospital, Medan, Indonesia, from April to October 2019. This study included neonates aged less than 28 days, diagnosed with suspected sepsis, and had no previous history of antibiotics administration. Patients underwent clinical assessment, laboratory examination, and blood culture. Patients were grouped into sepsis and non-sepsis based on the blood culture results. The median hematological examination and the range of NLR and PLR in both the sepsis and non-sepsis groups were subjected to analysis using the Mann-Whitney U test to assess differences. NLR and PLR optimal cut-off values were determined using a receiver operator curve (ROC) with a confidence interval of 95%. A total of 137 neonates were enrolled, of which 49 were classified as sepsis and 89 as non-sepsis based on blood culture results. The optimal cutoff values for NLR and PLR were 2.75 and 11.73. Using those cutoff values, NLR and PLR could predict neonatal sepsis with sensitivities of 52.1% and 47.9%, specificities of 50.6% and 47.2%, area under the curve (AUC) of 0.46 and 0.47, with p=0.525 and p=0.662, respectively. Further investigation is warranted to refine the NLR and PLR utility and enhance diagnostic accuracy in clinical practices.

Predictors of gentamicin therapy failure in neonates with sepsis

Sepsis is a common disease with high morbidity and mortality among newborns in intensive care units world-wide. Gram-negative bacillary bacteria are the major source of infection in neonates. Gentamicin is the most widely used aminoglycoside antibiotic in empiric therapy against early-onset sepsis. However, therapy failure may result due to various factors. The purpose of this study was to identify predictors of gentamicin therapy failure in neonates with sepsis. This was a prospective cross-sectional study at the Neonatal Intensive Care Unit at Windhoek Central Hospital over a period of 5 months in 2019. Neonates received intravenous gentamicin 5 mg/kg/24 h in combination with either benzylpenicillin 100 000 IU/kg/12 h or ampicillin 50 mg/kg/8 h. Logistic regression modeling was performed to determine the predictors of treatment outcomes. 36% of the 50 neonates were classified as having gentamicin treatment failure. Increasing treatment duration by 1 day resulted in odds of treatment failure increasing from 1.0 to 2.41. Similarly, one unit increase in CRP increases odds of gentamicin treatment failure by 49%. The 1 kg increase in birthweight reduces the log odds of treatment failure by 6.848, resulting in 99.9% decrease in the odds of treatment failure. One unit increase in WBC reduces odds of gentamicin treatment failure by 27%. Estimates of significant predictors of treatment failure were precise, yielding odds ratios that were within 95% confidence interval. This study identified the following as predictors of gentamicin therapy failure in neonates: prolonged duration of treatment, elevated C-reactive protein, low birthweight, and low white blood cell count.

Fetal chronic hypoxia does not affect urinary presepsin levels in newborns at birth

OBJECTIVES

Early sepsis detection and diagnosis still constitutes an open issue since the accuracy of standard-of care parameters is biased by a series of perinatal factors including hypoxia. Therefore, we aimed at investigating the effect of fetal chronic hypoxia insult on urine levels of a promising new marker of sepsis, namely presepsin (P-SEP).

METHODS

We conducted a prospective case-control study in 22 cases of early-intrauterine growth restriction (E-IUGR) compared with 22 small-for-gestational-age (SGA) newborns and 66 healthy controls. P-SEP urine samples were collected over the first 72 h from birth. Blood culture and C-reactive protein (CRP) blood levels were measured in E-IUGR and SGA infants. Perinatal standard monitoring parameters and main outcomes were also recorded.

RESULTS

No significant urinary P-SEP differences (p>0.05, for all) were observed among studied groups. Moreover, no significant correlations (p>0.05, for both) between urinary P-SEP and blood CRP levels in both E-IUGR and SGA groups (R=0.08; R=0.07, respectively) were observed.

CONCLUSIONS

The present results showing the lack of influence of fetal chronic hypoxia on urinary P-SEP levels offer additional data to hypothesize the possible use of urinary P-SEP measurement in neonates in daily clinical practice. Further multicenter prospective data are needed, including infants with early-onset sepsis.

***ECD*** maternal C-reactive protein as a predictor of neonatal sepsis

Systemic bacterial infection in the newborn has a significant impact on neonatal mortality and morbidity. Non-invasive prenatal markers of risk could be useful in the prediction and prevention of neonatal sepsis. We evaluated the association of maternal third-trimester serum level of C-Reactive Protein (CRP) with neonatal sepsis in a sample of infants in the JAKids pregnancy and birth cohort study. A population-based nested case-control design was used to identify cases and controls of neonatal sepsis from the subset of infants in the JAKids study whose mothers had serum archived in the early third trimester and who were admitted to newborn intensive care. Cases were 25 neonates with neonatal sepsis identified from hospital records. Controls were a random sample of 62 sepsis-free neonates matched to cases within three gestational age strata - ≤32 weeks, 33-36 weeks, and ≥37 weeks.Mothers of neonatal sepsis cases ≥37 weeks had significantly higher mean levels of maternal CRP protein than mothers of controls (11.0 mg/dL ± 3.0 vs. 8.7 mg/dL ± 5.9; p < .05). Differences in maternal CRP were not found in sepsis cases born ≤32 weeks (9.5 mg/dL ± 4.2 vs 5.8 mg/dL ± 4.0, p = .23) nor in sepsis cases born at 33-36 weeks (9.0 mg/dL ± 3.6 vs 11.9 mg/dL ± 7.8, p = .34). Maternal third-trimester C-reactive protein levels were elevated in mothers of term-born neonates with sepsis, but not in the mothers of preterm neonates with sepsis.

Early procalcitonin assays may reduce antibiotic exposure in premature newborn infants

AIM

The diagnosis of early-onset neonatal sepsis (EOS) remains difficult. The main aim was to study the effect of a new algorithm for EOS, which includes the level of procalcitonin in umbilical cord blood, on the exposure to antibiotic therapy of premature newborn infants.

METHODS

This was a monocentric, observational and retrospective study with before-and-after design. The duration and dose of antibiotic therapy provided as well as the morbidity and mortality were compared in two groups, one included 01 May 2015-30 November 2015 when procalcitonin was not used, and one after the change 01 November 2016-30 May 2017 when procalcitonin was used in a hospital setting in Nice, France.

RESULTS

Sixty newborn infants were included in the before group and 54 in the after group. Antibiotic therapy was stopped after 24 h for 18 newborn infants in the after group and four in the before group, and after 48 h for 26 newborn infants in the after group and 10 in the before group.

CONCLUSION

The implementation of a new decision-making algorithm including early procalcitonin assay of premature newborn infants significantly reduced exposure to antibiotics without modifying mortality or morbidity.

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.

Application of Advanced Molecular Methods to Study Early-Onset Neonatal Sepsis

Early-onset sepsis (EOS) is a global health issue, considered one of the primary causes of neonatal mortality. Diagnosis of EOS is challenging because its clinical signs are nonspecific, and blood culture, which is the current gold-standard diagnostic tool, has low sensitivity. Commonly used biomarkers for sepsis diagnosis, including C-reactive protein, procalcitonin, and interleukin-6, lack specificity for infection. Due to the disadvantages of blood culture and other common biomarkers, ongoing efforts are directed towards identifying innovative molecular approaches to diagnose neonates at risk of sepsis. This review aims to gather knowledge and recent research on these emerging molecular methods. PCR-based techniques and unrestricted techniques based on 16S rRNA sequencing and 16S-23S rRNA gene interspace region sequencing offer several advantages. Despite their potential, these approaches are not able to replace blood cultures due to several limitations; however, they may prove valuable as complementary tests in neonatal sepsis diagnosis. Several microRNAs have been evaluated and have been proposed as diagnostic biomarkers in EOS. T2 magnetic resonance and bioinformatic analysis have proposed potential biomarkers of neonatal sepsis, though further studies are essential to validate these findings.

Investigating the Association between Serum and Hematological Biomarkers and Neonatal Sepsis in Newborns with Premature Rupture of Membranes: A Retrospective Study

(1) Background: Neonatal early-onset sepsis (EOS) is associated with important mortality and morbidity. The aims of this study were to evaluate the association between serum and hematological biomarkers with early onset neonatal sepsis in a cohort of patients with prolonged rupture of membranes (PROM) and to calculate their diagnostic accuracy. (2) Methods: A retrospective cohort study was conducted on 1355 newborns with PROM admitted between January 2017 and March 2020, who were divided into two groups: group A, with PROM ≥ 18 h, and group B, with ROM < 18 h. Both groups were further split into subgroups: proven sepsis, presumed sepsis, and no sepsis. Descriptive statistics, analysis of variance (ANOVA) and a Random Effects Generalized Least Squares (GLS) regression were used to evaluate the data. (3) Results: The statistically significant predictors of neonatal sepsis were the high white blood cell count from the first (p = 0.005) and third day (p = 0.028), and high C-reactive protein (CRP) values from the first day (p = 0.004). Procalcitonin (area under the curve-AUC = 0.78) and CRP (AUC = 0.76) measured on the first day had the best predictive performance for early-onset neonatal sepsis. (4) Conclusions: Our results outline the feasibility of using procalcitonin and CRP measured on the first day taken individually in order to increase the detection rate of early-onset neonatal sepsis, in the absence of positive blood culture.

Neonatal early-onset sepsis calculator: Impact on antibiotic use in a level II neonatal unit in Western Australia

BACKGROUND

Overuse of empirical intravenous antibiotics in neonates in high-income countries (HICs) is well documented. The Kaiser Permanente neonatal early-onset sepsis (EOS) calculator is an evidence-based sepsis risk assessment tool that has demonstrated potential to reduce antibiotic usage in this population. The incidence of early-onset sepsis in most HICs is 0.4-0.8 per 1000 live births. The objective was to evaluate the calculator's impact on antibiotic rates and length of stay in a regional level II Special Care Nursery.

METHODS

A single-centre retrospective cohort study compared antibiotic administration rates in the first 72 h in neonates ≥35 weeks gestation born during two 6-month periods in 2019 (pre-EOS calculator) and 2021 (post-EOS calculator). Electronic and paper case records were accessed to capture data. Continuous data were summarised using mean and standard deviation, and categorical data were summarized using frequency distributions. There were 951 (2019) and 1129 (2021) infants born during the study periods.

RESULTS

Following implementation of the calculator, antibiotic exposure decreased from 13.7% to 4.7% of all neonates without reported negative outcomes. Mean length of stay for neonates born across the two periods decreased from 2.38 to 2.13 days. Indications for antibiotic use shifted more towards clinical condition and away from obstetric risk factors. There were no culture-proven cases of sepsis or readmissions with EOS in either period.

CONCLUSION

Implementation of the EOS calculator significantly reduced exposure to antibiotics, without adverse outcomes.

Association Between Hypoglycemia and the Occurrence of Early Onset Sepsis in Premature Infants

BACKGROUND

We examined the association between hypoglycemia and the occurrence of early onset sepsis (EOS) in premature infants admitted to the neonatal intensive care unit (NICU).

METHODS

We included infants discharged from 358 NICUs between 1997 and 2020 with gestational age <34 weeks, ≥1 culture collected in the first 3 days of life, and ≥1 serum glucose value recorded on the day of or day prior to culture collection. We used multivariable logistic regression and inverse probability weighting (IPW) and constructed models for three definitions of hypoglycemia: American Academy of Pediatrics (AAP), Pediatric Endocrine Society, and a definition based on neurodevelopmental studies. We performed subgroup analysis in EOS episodes caused by Gram-negative and Gram-positive organisms.

RESULTS

Of the 62,178 infants and 64,559 cultures that met study inclusion criteria, 739 (1%) cultures were positive. The median (25th, 75th percentile) glucose value was 75 mg/dL (50, 106) on the day of or day prior to a positive culture versus 70 mg/dL (50, 95) on the day of or day prior to a negative culture. We found that hypoglycemia was not associated with the occurrence of EOS for all organisms and Gram-positive organisms, whereas there was a small but significant association between the lower AAP glucose cutoff value and EOS due to Gram-negative organisms (logistic regression: risk difference [RD] 0.24% [95% CI, 0.01-0.47]; IPW: RD 0.22% [95% CI, 0.00-0.43]).

CONCLUSIONS

Hypoglycemia may be an early marker of EOS, particularly in episodes caused by Gram-negative organisms and when using a stricter definition of hypoglycemia.

Advancement in biomarker based effective diagnosis of neonatal sepsis

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.

Diagnostic Accuracy of Multiplex Polymerase Chain Reaction in Early Onset Neonatal Sepsis

Early onset neonatal sepsis is a significant contributor to neonatal morbidity and mortality. Although blood cultures remain the diagnostic gold standard, they detect pathogens in only a minority of suspected cases. This study compared the accuracy of blood cultures with a rapid multiplex PCR test. Newborns at risk of neonatal sepsis were prospectively screened as recommended per national guidelines. Evaluations included laboratory parameters (CrP, IL6, differential blood count), blood culture, and a molecular multiplex PCR test (ROCHE LightCycler SeptiFast®) identifying 20 common microbial agents. Blood samples were taken simultaneously from umbilical cord or venous sources on the first day of life. Of 229 infants included, 69% were born preterm. Blood culture and multiplex PCR sensitivity were 7.4% and 14.8%, respectively. Specificity, negative and positive predictive values between methods showed no significant variance, although multiplex PCR had more false positives due to contamination. The limited sensitivity of blood cultures for early onset neonatal sepsis is concerning. Despite quicker results, multiplex PCR does not enhance diagnostic accuracy or antibiotic therapy guidance, thus it cannot be recommended for this indication.

Early Diagnostic Markers of Late-Onset Neonatal Sepsis

OBJECTIVE

Early diagnosis of nosocomial infections in newborns is a great challenge, because in the initial phase of systemic infection, clinical symptoms are often non-specific, and routinely used hematological markers are not sufficiently informative. The aim of this study was to determine the potential of early inflammatory markers to diagnose late-onset neonatal sepsis-procalcitonin (PCT), interleukin 6 (IL-6), interleukin 8 (IL-8) and endocan (ESM-1).

MATERIAL AND METHODS

A prospective clinical-epidemiological study was conducted in a third-level NICU in Pleven, Bulgaria. Patients with suspected late-onset sepsis and healthy controls were tested. A sandwich ELISA method was used to measure the serum concentrations of biomarkers.

RESULTS

Sixty newborns were included, of which 35% symptomatic and infected, 33.3% symptomatic but uninfected and 31.7% asymptomatic controls. The mean values of PCT, IL-6, I/T index and PLT differ significantly in the three groups. For ESM-1, IL-8 and CRP, the difference was statistically insignificant. The best sensitivity (78%) and negative predictive value (84%) was found for IL-6. The combinations of PCT + IL-6 and PCT + IL-6+ I/T+ PLT showed very good diagnostic potential.

CONCLUSION

The introduction into the routine practice of indicators such as PCT and IL-6 may provide an opportunity to promptly optimize the diagnostic and therapeutic approach to LOS.

Insight Into Neonatal Sepsis: An Overview

There are approximately 1.3 million cases of neonatal sepsis reported worldwide with deaths occurring more commonly in preterm and low-weight newborns. Neonatal sepsis is the third major cause of neonatal deaths resulting in 203,000 deaths per year. It is divided into two subtypes based on time of occurrence: early-onset neonatal sepsis (ENS), occurring within the first 72 hours of birth usually due to perinatal risk factors, and late-onset neonatal sepsis (LOS) usually occurring after the first week of life and up to 28th day of life. There are many complications associated with neonatal sepsis including septic shock, multiple organ failure, and death. It is vital for clinicians to know the signs and symptoms of neonatal sepsis in order to diagnose it early. Preventive measures, early diagnosis, appropriate antibiotic administration, timely supportive management, and the establishment of efficient management are vital in the prevention of severe complications or death. In this review, we aim to provide the most up-to-date information regarding risk factors, pathophysiology, signs and symptoms, diagnosis, and treatment of neonatal sepsis. We discuss the maternal and neonatal risk factors involved in the pathogenesis of neonatal sepsis and the signs and symptoms of early and late neonatal sepsis. We focus on the different pathogens involved and the markers used in the diagnosis and treatments available for each.

Potential of Molecular Culture in Early Onset Neonatal Sepsis Diagnosis: A Proof of Principle Study

Delay in the time-to-positivity of a peripheral blood culture (PBC), the gold standard for early onset neonatal sepsis (EOS) diagnosis, has resulted in excessive use of antibiotics. In this study, we evaluate the potential of the rapid Molecular Culture (MC) assay for quick EOS diagnosis. In the first part of this study, known positive and spiked blood samples were used to assess the performance of MC. In the in vivo clinical study, the second part of this study, all infants receiving antibiotics for suspicion of EOS were included. At initial EOS suspicion, a blood sample was collected for PBC and MC. MC was able to detect bacteria present in the spiked samples even when the bacterial load was low. In the clinical study, MC was positive in one infant with clinical EOS (Enterococcus faecalis) that was not detected by PBC. Additionally, MC was positive in two infants without clinical sepsis (Streptococcus mitis and multiple species), referred to as contamination. The other 37 samples were negative both by MC and PBC. MC seems to be able to detect bacteria even when the bacterial load is low. The majority of MC and PBC results were comparable and the risk for contamination and false positive MC results seems to be limited. Since MC can generate results within 4 h following sampling compared with 36-72 h in PBC, MC may have the potential to replace conventional PBC in EOS diagnostics in order to guide clinicians on when to discontinue antibiotic therapy several hours after birth.

Can Presepsin Be Valuable in Reducing Unnecessary Antibiotic Exposure after Birth?

Background: Due to a lack of rapid, accurate diagnostic tools for early-onset neonatal sepsis (EOS) at the initial suspicion, infants are often unnecessarily given antibiotics directly after birth. We aimed to determine the diagnostic accuracy of presepsin for EOS before antibiotic initiation and to investigate whether presepsin can be used to guide clinicians’ decisions on whether to start antibiotics. Methods: In this multicenter prospective observational cohort study, all infants who started on antibiotics for EOS suspicion were consecutively included. Presepsin concentrations were determined in blood samples collected at the initial EOS suspicion (t = 0). In addition to this, samples were collected at 3, 6, 12 and 24 h after the initial EOS suspicion and from the umbilical cord directly after birth. The diagnostic accuracy of presepsin was calculated. Results: A total of 333 infants were included, of whom 169 were born preterm. We included 65 term and 15 preterm EOS cases. At the initial EOS suspicion, the area under the curve (AUC) was 0.60 (95% confidence interval (CI) 0.50–0.70) in the term-born infants compared to 0.84 (95% CI 0.73–0.95) in the preterm infants. A cut-off value of 645 pg/mL resulted in a sensitivity of 100% and a specificity of 54% in the preterm infants. The presepsin concentrations in cord blood and at other time points did not differ significantly from the concentrations at the initial EOS suspicion. Conclusions: Presepsin is a biomarker with an acceptable diagnostic accuracy for EOS (culture-proven and clinical EOS) in preterm infants and might be of value in reducing antibiotic exposure after birth when appended to current EOS guidelines. However, the small number of EOS cases prevents us from drawing firm conclusions. Further research should be performed to evaluate whether appending a presepsin-guided step to current EOS guidelines leads to a safe decrease in antibiotic overtreatment and antibiotic-related morbidity.

Vaginal and neonatal microbiota in pregnant women with preterm premature rupture of membranes and consecutive early onset neonatal sepsis

BACKGROUND

Preterm premature rupture of membranes (PPROM), which is associated with vaginal dysbiosis, is responsible for up to one-third of all preterm births. Consecutive ascending colonization, infection, and inflammation may lead to relevant neonatal morbidity including early-onset neonatal sepsis (EONS). The present study aims to assess the vaginal microbial composition of PPROM patients and its development under standard antibiotic therapy and to evaluate the usefulness of the vaginal microbiota for the prediction of EONS. It moreover aims to decipher neonatal microbiota at birth as possible mirror of the in utero microbiota.

METHODS

As part of the PEONS prospective multicenter cohort study, 78 women with PPROM and their 89 neonates were recruited. Maternal vaginal and neonatal pharyngeal, rectal, umbilical cord blood, and meconium microbiota were analyzed by 16S rRNA gene sequencing. Significant differences between the sample groups were evaluated using permutational multivariate analysis of variance and differently distributed taxa by the Mann-Whitney test. Potential biomarkers for the prediction of EONS were analyzed using the MetaboAnalyst platform.

RESULTS

Vaginal microbiota at admission after PPROM were dominated by Lactobacillus spp. Standard antibiotic treatment triggers significant changes in microbial community (relative depletion of Lactobacillus spp. and relative enrichment of Ureaplasma parvum) accompanied by an increase in bacterial diversity, evenness and richness. The neonatal microbiota showed a heterogeneous microbial composition where meconium samples were characterized by specific taxa enriched in this niche. The vaginal microbiota at birth was shown to have the potential to predict EONS with Escherichia/Shigella and Facklamia as risk taxa and Anaerococcus obesiensis and Campylobacter ureolyticus as protective taxa. EONS cases could also be predicted at a reasonable rate from neonatal meconium communities with the protective taxa Bifidobacterium longum, Agathobacter rectale, and S. epidermidis as features.

CONCLUSIONS

Vaginal and neonatal microbiota analysis by 16S rRNA gene sequencing after PPROM may form the basis of individualized risk assessment for consecutive EONS. Further studies on extended cohorts are necessary to evaluate how far this technique may in future close a diagnostic gap to optimize and personalize the clinical management of PPROM patients.

TRIAL REGISTRATION

NCT03819192, ClinicalTrials.gov. Registered on January 28, 2019.

The Role of Coagulase-Negative Staphylococci Biofilms on Late-Onset Sepsis: Current Challenges and Emerging Diagnostics and Therapies

Infections are one of the most significant complications of neonates, especially those born preterm, with sepsis as one of the principal causes of mortality. Coagulase-negative staphylococci (CoNS), a group of staphylococcal species that naturally inhabit healthy human skin and mucosa, are the most common cause of late-onset sepsis, especially in preterms. One of the risk factors for the development of CoNS infections is the presence of implanted biomedical devices, which are frequently used for medications and/or nutrient delivery, as they serve as a scaffold for biofilm formation. The major concerns related to CoNS infections have to do with the increasing resistance to multiple antibiotics observed among this bacterial group and biofilm cells’ increased tolerance to antibiotics. As such, the treatment of CoNS biofilm-associated infections with antibiotics is increasingly challenging and considering that antibiotics remain the primary form of treatment, this issue will likely persist in upcoming years. For that reason, the development of innovative and efficient therapeutic measures is of utmost importance. This narrative review assesses the current challenges and emerging diagnostic tools and therapies for the treatment of CoNS biofilm-associated infections, with a special focus on late-onset sepsis.

Economic and Diagnostic Biomarker Tests of Neonatal Sepsis: A Prospective Study from a Tertiary Care Hospital in a Low-Income Country

Background. Neonatal sepsis is a leading cause of morbidity and mortality in low-and middle-income countries (LMICs). There are several sophisticated biomarkers; however, they are still insufficient in precision. In this perspective, our study aims to search for a pragmatic diagnostic biomarker in the age category. Methods. A cross-sectional study was conducted over six months(April-September 2018). All neonates with a diagnosis of probable sepsis were included. Logistic regression analysis of demographic variables was done to elucidate any association with confirmed sepsis cases. The median with interquartile range (IQR)] and mean with standard deviation (SD) were calculated, and then compared. The area under the receiver operating characteristic curve (AUROC) of the commonly opted biomarker tests [distribution width of red blood cells (RDW) and platelets(PDW), mean platelet volume(MPV), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)] was compared to the culture-confirmed case. Results. Of the 171 suspected sepsis subjects, we discovered a significant burden of newborn sepsis, with 18.7% of cases being culture-confirmed. 66 Early-onset sepsis(EOS) and 105 Late-onset sepsis(LOS) probable sepsis cases were enrolled. A higher incidence was revealed among male infants 24(14%) compared to females 8(4.7%). On logistic regression analysis, preterm birth [odds ratio (OR): 10.9, 95% confidence interval (CI): 4.5-26.9] and low birth weight (OR: 6.5, 95% CI: 2.4-17.9) were significantly associated. Coagulase-negative Staphylococcus aureus (CoNS) (n =6) among gram-positive, and Pseudomonas aeruginosa (n =6) was among gram-negative, were the leading etiologies. Escherichia coli (n =3) was the predominant bacteria in EOS subjects, while Pseudomonas aeruginosa (n =6) among LOS. Median interquartile range(IQR): platelet count 144.5(99-192), red cell distribution width 18(16.9-20), CRP 6(3-18.3); and mean ± SD: MPV (11.7 ± 1.7); PDW (15.2 ± 3.5) were attained, among confirmed cases. The AUROC, of biomarker tests was attained in the order: PDW(0.86) > MPV(0.81) > RDW(0.76) > CRP(0.67) > ESR(0.59); similarly, the cut-off order was >11.2, >10.4, >16.8, >2.9, >4.5, respectively. Conclusions. Our finding shows an increment in the width and volume of RBCand platelet: RDW, MPV, and PDW have a diagnostic role in neonatal sepsis.

Amino acids for the prevention of mortality and morbidity in preterm infants: a systematic review and network meta-analysis

To determine the effectiveness and safety of amino acids in preventing the mortality and morbidity among preterm infants. We conducted a systematic review and network meta-analysis. We searched MEDLINE, EMBASE, Web of Science, CINAHL, Scopus, Cochrane, and Google Scholar, and grey literature, from databases inception to January 2021. We included randomized trials that evaluated any amino acids on preterm or low-birth weight infants. We performed frequentist pairwise and network meta-analyses and used the GRADE methodology to assess the certainty of the evidence and provide a summary of the results.We included 18 trials (3702 infants). Low certainty evidence showed that there seems to be no benefit for arginine, glutamine, or N-acetylcysteine in reducing all-cause mortality. Oral arginine likely results in reduction of necrotizin enterocolitis (NEC) stage ≥ II (OR 0.48; 95% CI 0.26-0.90; moderate certainty). Oral glutamine may reduce the likelihood of developing late-onset sepsis (LOS) compared to placebo (OR 0.62; 95% CI 0.47-0.82; low certainty); and likely reduces time to reach full enteral feeding (MD = - 2.63 days; 95% CI - 4.99 to - 0.27; moderate certainty). Amino acids may have no effect on mortality. Oral arginine may reduce severe NEC, and oral glutamine may reduce LOS and the time to reach full feeding.Systematic review registration: PROSPERO registration number: CRD4201603873.

Knowledge of nurses on neonatal sepsis: a tertiary teaching hospital-based study

Neonatal sepsis is a significant cause of morbidity and mortality in hospitalized newborns and premature infants. Therefore, knowledge of essential newborn Care (ENC) is important for a newborn's survival, growth and development. The aim of this study was to assess the knowledge of nurses regarding essential newborn care in our Special Care Neonatal Unit (SCNU). Methods: A descriptive cross-sectional study was conducted between 1st September 2021 and 30th November 2021 among the nurses working in SNCU of Government Medical College and Hospital (GMC), Doda, Jammu and Kashmir, India. Data were was collected using a pre-tested questionnaire by purposive sample. Collected data were checked, and coding was done and analyzed using SPSS 20 software. Results: 72.0 % of nurses were of the age group of 21–30 years. The majority (74 %) were females, 78 % had completed B Sc Nursing, and 66 % had experience of 2 to 4 years. Most of the nurses had good knowledge about ENC, about basic equipment’s used in SNCU, and about advanced equipment’s or procedures had less knowledge. All nurses answered bacteria correctly as a causative organism of neonatal sepsis. Conclusions: Most of the nurses working in the SCNU of GMC Doda had good knowledge regarding ENC. The knowledge appeared irrespective of their age, gender, religion, educational status, working place and special courses/training in neonatology.

Clinical Utility of A Model-based Amoxicillin Dosage Regimen in Neonates with Early-Onset Sepsis

Early-onset sepsis (EOS) is one of the most significant causes of morbidity and mortality in neonates. Currently, amoxicillin is empirically used to treat neonates with EOS. However, data on its effectiveness in neonates with EOS are still limited. Therefore, we aimed to evaluate the pharmacodynamics (PD) target attainment and effectiveness of a model-based amoxicillin dosage regimen in these neonates. We used a previously developed model and collected additional clinical data from the EOS neonates who used the model-based dosage regimen (25 mg/kg q12h). The primary outcomes were PD target attainment (free drug concentration above MIC during 70% of the dosing interval) and treatment failure rate. The secondary endpoints were length of amoxicillin treatment, duration of hospitalization, etc. Seventy-five neonates (postmenstrual age 28.4-41.6 weeks) were enrolled. A total of 70 (93.3%) neonates reached their PD target using 1 mg/L as the MIC breakpoint. The treatment failure rate was 10.7%.

Umbilical cord blood culture in neonatal early-onset sepsis: a systematic review and meta-analysis

BACKGROUND

Peripheral blood culture (PBC) is considered the gold standard for diagnosis of neonatal early-onset sepsis (EOS), but its diagnostic value can be questioned. We aimed to systematically asses the diagnostic test accuracy (DTA) of umbilical cord blood culture (UCBC) for EOS.

METHODS

A systematic literature search was performed in PubMed, Embase, Web of Science, and the Cochrane Library. Studies performing UCBC for the diagnosis of EOS were included.

RESULTS

A total of 1908 articles were screened of which 17 were included. Incidences of positive PBC and UCBC were low in all studies. There was a large heterogeneity in the consistency between positive PBC and UCBC outcomes. PBC had a pooled sensitivity of 20.4% (95% CI 0.0-40.9) and specificity of 100.0% (95% CI 100.0-100.0) compared to 42.6% (95% CI 12.7-72.4%) and 97.8% (95% CI 93.1-100.0) of UCBC for clinical EOS, defined as clinical sepsis regardless of PBC outcomes.

CONCLUSIONS

This systematic review shows that, compared to PBC, UCBC has higher sensitivity and comparable specificity for clinical EOS and might be considered as diagnostic test for EOS. Due to the limited number of studies, low incidences of EOS cases, and the imperfect reference standards for EOS, results should be interpreted cautiously.

IMPACT

This is the first systematic review and meta-analysis investigating the diagnostic test accuracy of umbilical cord blood culture for neonatal early-onset sepsis. Peripheral blood culture is considered the gold standard for diagnosis of neonatal early-onset sepsis, but its value for this specific diagnosis can be questioned. Umbilical cord blood culture has higher sensitivity and comparable specificity for diagnosis of neonatal early-onset sepsis compared to peripheral blood culture, circumventing the risk for iatrogenic anemia and consequently might be used as a diagnostic tool for early-onset sepsis. Quality of evidence was regarded as low due to imperfect diagnostic methods of neonatal early-onset sepsis.

Time to recovery of neonatal sepsis and determinant factors among neonates admitted in Public Hospitals of Central Gondar Zone, Northwest Ethiopia, 2021

Background

Neonatal sepsis is a leading cause of neonatal morbidity and mortality, particularly in developing countries. Time to recovery is an indicator of the severity of sepsis, and risk factors varied significantly according to study population and settings. Moreover, published literature regarding the time to recovery of neonatal sepsis is scarce.

Objective

The aim of this study was to assess the time to recovery of neonatal sepsis and determinant factors among neonates admitted in the Public Hospitals of Central Gondar Zone, Northwest Ethiopia.

Methods

An institution-based prospective follow-up study design was conducted among 631 neonates with sepsis. A structured, pre-tested, interviewer-administered questionnaire was used. The median time to recovery, life-table, the Kaplan Meier curve, and the log-rank test were computed. Both bi-variable and multivariable Cox regression models were applied to analyze the data.

Results

Of all septic neonates, 511 successfully recovered. They were followed for a total of 4,740-neonate day’s observation and the median time to recovery was 7 days (IQR = 5–10 days). After adjusting for covariates, intrapartum fever (AHR = 0.69, 95%CI: 0.49, 0.99), induced onset of labor (AHR = 0.68, 95%CI: 0.49, 0.94), chest indrawing (AHR = 0.67, 95%CI: 0.46, 0.99), late onset sepsis (AHR = 0.55, 95%CI: 0.40, 0.75), non-oral enteral feeding (AHR = 0.38, 95%CI: 0.29, 0.50), assisted with bag and mask (AHR = 0.72, 95%CI: 0.56, 0.93), normal birth weight (AHR = 1.42, 95%CI: 1.03, 1.94), gestational age of 37–42 weeks (AHR = 1.93, 95%CI: 1.32, 2.84), septic shock (AHR = 0.08, 95%CI: 0.02, 0.39), infectious complications (AHR = 0.42, 95%CI: 0.29, 0.61), being in critical conditions (AHR = 0.68, 95%CI: 0.52, 0.89), and early recognition of illness (AHR = 1.83, 95%CI: 1.27, 2.63) were independently associated with the time to recovery of neonatal sepsis.

Conclusions and recommendations

The time to recovery of this study was moderately acceptable as compared to the previous studies. The above-mentioned factors could be used for the early identification of neonates with sepsis at risk for protracted illness and it could guide prompt referral to higher centers in primary health sectors. This also will provide prognostic information to clinicians and families as longer recovery time has economic and social implications in our country.

Predictive Scores for Late-Onset Neonatal Sepsis as an Early Diagnostic and Antimicrobial Stewardship Tool: What Have We Done So Far?

Background: Late-onset neonatal sepsis (LOS) represents a significant cause of morbidity and mortality worldwide, and early diagnosis remains a challenge. Various ‘sepsis scores’ have been developed to improve early identification. The aim of the current review is to summarize the current knowledge on the utility of predictive scores in LOS as a tool for early sepsis recognition, as well as an antimicrobial stewardship tool. Methods: The following research question was developed: Can we diagnose LOS with accuracy in neonates using a predictive score? A systematic search was performed in the PubMed database from 1982 (first predictive score published) to December 2021. Results: Some (1352) articles were identified—out of which, 16 were included in the review. Eight were original scores, five were validations of already existing scores and two were mixed. Predictive models were developed by combining a variety of clinical, laboratory and other variables. The majority were found to assist in early diagnosis, but almost all had a limited diagnostic accuracy. Conclusions: There is an increasing need worldwide for a simple and accurate score to promptly predict LOS. Combinations of the selected parameters may be helpful, but until now, a single score has not been proven to be comprehensive.

Admission Outcome and Antimicrobial Resistance Pattern of Bacterial Isolates among Neonates with Suspected Sepsis in Neonatal Intensive Care Unit at Dessie Comprehensive Specialized Hospital, Dessie, Northeastern Ethiopia

Background

Neonatal sepsis is a major cause of morbidity and mortality globally. The aim of this study was to assess admission outcome and antimicrobial susceptibility pattern of bacterial isolates among neonates with suspected sepsis at the Dessie Comprehensive specialized Hospital (DCSH), Northeastern Ethiopia.

Method

Cross-sectional study was conducted from August 2017 to March 2018. Two hundred forty-six neonates were recruited, and each patient's blood specimen was collected aseptically using bottle containing Brain Heart Infusion for blood culture. Both clinical and laboratory data such as bacterial culture growth and antimicrobial susceptibility pattern were collected from the neonate; clinical data from the mothers were also included. Antimicrobial susceptibility testing was performed using Kirby-Bauer disk diffusion method. The data were analyzed using SPSS version 20.

Results

Bacteria were identified from 67 (27.2%) blood cultures. The predominant pathogen was Escherichia coli (35.8%) followed by Staphylococcus aureus (26.8%), and Coagulase Negative Staphylococcus (CoNS) (19.4%). The isolated bacteria showed resistance to Ampicillin 55 (82%), third-generation Cephalosporins 21 (58.3%) and other tested antimicrobials. Overall, 68.6% bacterial isolates demonstrated Multidrug resistance (MDR) and total registered mortality rate was 12/246 (4.8%). Both neonatal factors such as neonatal temperature, septic umbilicus and utilization of indwelling medical device during delivery; and maternal factors such as age, antenatal urinary tract infection (UTI), mode of delivery and prolonged rupture of membrane (PROM) had shown statistically significant association with bacterial sepsis.

Conclusion

The rate of bacterial growth was found to be high; E. coli and S. aureus were the predominant organisms. Both maternal and neonatal related data were strong predictors for bacterial infection of the neonate. Therefore, improving infrastructures for screening of bacteremia as well as active surveillance in clinical setting needed to ensure proper empirical therapy.

External Validation of a Vancomycin Population Pharmacokinetic Model and Developing a New Dosage Regimen in Neonates

BACKGROUND AND OBJECTIVE

Vancomycin is the drug of choice in the treatment of MRSA infections. In a published vancomycin population pharmacokinetic study on neonates in Singapore healthcare institutions, it was found that vancomycin clearance was predicted by weight, postmenstrual age, and serum creatinine. The aim of this study was to externally validate the vancomycin population pharmacokinetic model to develop a new dosage regimen in neonates, and to compare this regimen with the existing institutional and NeoFax^® dosage regimens.

METHODS

A retrospective chart review of neonates who received vancomycin therapy and therapeutic drug monitoring was conducted. The median prediction error percentage was calculated to assess bias, while the median absolute prediction error percentage and the root mean squared error percentage were calculated to assess precision. The new dosage regimen was developed using Monte Carlo simulation.

RESULTS

A total of 20 neonates were included in the external validation dataset. Eighteen of them were premature, with a median gestational age of 27.7 (25.9-31.5) weeks and postmenstrual age of 30.5 (27.3-34.3) weeks at the point of vancomycin initiation. No apparent systematic bias was found in the predictions of the model. The external validation performed in the current study found the model to be generally unbiased. Our new vancomycin dosage regimen was able to achieve target trough concentrations and area under the curve (AUC₂₄) at a greater proportion as compared to existing institutional and NeoFax^® dosage regimens.

CONCLUSION

The pharmacokinetic model built in the previous study can be used to conduct reliable population simulations of our Asian neonatal population in Singapore. The new dosage regimen was able to achieve target trough concentrations and AUC₂₄ better than existing institutional and NeoFax^® dosage regimens.

Perinatal presepsin assessment: a new sepsis diagnostic tool?

Perinatal sepsis constitutes a medical emergency and is still one of the major causes of mortality and morbidity. The possibility of an early diagnosis of sepsis is still debated and controversial. In particular, clinical symptoms can be hidden by the association of sepsis with other perinatal diseases and/or by therapeutic strategies performed. In this context, there is evidence that the accuracy of standard of care diagnostic parameters (i.e. blood culture, C-reactive protein, procalcitonin) can be biased by additional confounding factors (gestational age, birth-weight, acute-chronic hypoxia). Therefore, the inclusion in clinical daily practice of new biomarkers of sepsis is of utmost importance. Of a panel of biomarkers, Presepsin (P-SEP) plays an important role in the development and response of the immune system and as an early marker of sepsis both in adult and pediatric patients. Therefore, in the present review we aim to offer an overview of the role of P-SEP in the early detection of perinatal sepsis as a trustworthy marker according to actual statements of official international institutions. Future perspectives regard the possibility of a longitudinal non-invasive biological fluids P-SEP assessment thus limiting the sample stress in high risk newborns.

Risk factors and predictive markers for early and late-onset neonatal bacteremic sepsis in preterm and term infants

BACKGROUND

The early detection and prediction of bacteremic sepsis in preterm and term neonates remains a challenging task because of their nonspecific clinical presentations. We aimed to investigate the risk factors associated with bacteremia and find the cutoff values of predictive markers to achieve accurate diagnosis of neonatal bacteremic sepsis.

METHODS

Not-doing-well preterm and term neonates with suspected sepsis were retrospectively enrolled between January 2015 and December 2017 in Taipei Veterans General Hospital. Blood culture, hemogram, serum procalcitonin (PCT), and C-reactive protein (CRP) were drawn at the onset of clinical signs and symptoms. All cases were divided to either early-onset or late-onset groups according to postpartum age. Nonparametric statistic, logistic regression, and receiver operating characteristic analysis were performed to evaluate the risk factors and cutoff values for predicting bacteremia.

RESULTS

A total of 169 suspected sepsis episodes were analyzed, 68.0% of which had cardiopulmonary dysfunction and 19.5% had perinatal stress. The early-onset group had 123 (72.8%) patients, 4 of which had bacteremia and 119 had nonbacteremia conditions. The late-onset group had 46 (27.2%) patients, 8 of which had bacteremia and 38 had nonbacteremia conditions. Gestational age, birth body weight, Apgar score at 5 minutes, serum PCT, CRP, and platelet (PLT) count in the early-onset group and white blood cell (WBC) count in the late-onset group were substantially different between the patients with bacteremia and nonbacteremia conditions. PCT greater than 27 µg/L (adjusted odd ratio [aOR], 21.6; 95% CI, 1.1-435.1) and thrombocytopenia less than 100 × 109/L (aOR, 38.6; 95% CI, 1.4-1030.3) were predictive markers for bacteremia in the early-onset group.

CONCLUSION

Early- and late-onset neonatal sepsis had different risk factors and predictive markers of bacteremia. PCT and PLT count in the early-onset group and WBC count in the late-onset group were accurate diagnostic serum markers for neonatal bacteremic sepsis.

Biomarkers of Neonatal Sepsis: From Being Mere Numbers to Becoming Guiding Diagnostics

Neonatal sepsis is a common cause of neonatal morbidity and mortality. The diagnosis of newborn sepsis is still difficult. Different early objective diagnostic tests or specific signs and symptoms, particularly in preterm infants, make it difficult to diagnose neonatal sepsis. This review article describes biomarkers and their role in the early diagnosis, treatment, and prognosis of neonatal sepsis. It also explores the possible advances and future prospects of these biomarkers. An ideal sepsis biomarker will not only help in the guidance of the use of antibiotics when not needed but also the duration of the course of antibiotics if sepsis is proven. It should also have high sensitivity, specificity, positive predictive value, and negative predictive value. These biomarkers hold a promising position in the management of neonatal sepsis and translate into use in clinical settings. Metabolomics, a diagnostic method based on detecting metabolites found in biological fluids, may open new possibilities in the management of critically ill newborns.

Exploring functional metabolites in preterm infants

AIM

Metabolomics is the study of small molecules that represent the functional end points of cellular reactions that can impact health. Necrotising enterocolitis (NEC) and late onset sepsis (LOS) are the main cause of death in preterm infants surviving the initial days of life.

METHODS

This review will explore and summarise the current literature exploring metabolomics in preterm infants.

RESULTS

There are a relatively limited number of studies investigating metabolomics in preterm infants with NEC and/or LOS and matched controls. Nonetheless, it is evident across longitudinally age-related metabolomic studies that there are significant changes in metabolite profiles post-partum and over the first year of life. Existing studies have reported associations between the metabolite profiles of serum, urine and stool in health and disease in preterm infants. Although some studies have found selected metabolites are associated with disease, the specific metabolites vary from study to study, and larger studies are required. Excitingly, recent work has also begun to untangle how microbially produced metabolites can impact immunoregulation of the infant.

CONCLUSION

Metabolic exploration is an emerging research area with huge potential for developing novel biomarkers and better understanding disease processes in preterm infants.

Investigation of salivary C-reactive protein and interleukin-18 for the diagnosis of neonatal sepsis

BACKGROUND

Neonatal sepsis is a leading cause of death in neonates worldwide. The investigation of biomarkers for the early diagnosis of neonatal sepsis is in progress with controversial outcomes. The current report aims to evaluate the values of salivary C-reactive protein (CRP) and interleukin-18 (IL-18) for the diagnosis of neonatal sepsis.

MATERIALS AND METHODS

In this cross-sectional study, 89 neonates, including 49 neonatal septic case and 40 healthy group admitted at the neonatal intensive care unit, were evaluated. The salivary samples of IL-18 and CRP were measured before the antibiotic therapy initiation, as soon as blood samplings. Sepsis diagnosis was confirmed by the positive blood culture. The diagnostic values of the biomarkers were determined using the receiver operating characteristic curve (ROC curve) analysis. Besides, the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic accuracy were measured.

RESULTS

Salivary CRP level was remarkably higher in septic case than healthy group (5.2 ± 4.61 vs. 3.5 ± 1.7; P = 0.02), while salivary IL-18 was not different between the groups (0.1 ± 0.29 vs. 0.04 ± 0.19; P = 0.25). The ROC curve for IL-18 showed insignificant values (P = 0.37). The ROC curve of salivary CRP showed area under the curve of 0.63 (95% confidence interval: 0.51-0.74; P = 0.03) with the sensitivity, specificity, PPV, NPV, LR+, LR - and diagnostic accuracy of 44.9% (31.8-58.7), 80% (65.2-89.5), 73.3% (55.5-85.82), 54.2% (41.6-66.3), 60.6% (50.29-70.18), 2.24 (1.57-3.2), and 0.68 (0.63-0.75) at the cutoff of 4.55 ng/L, respectively.

CONCLUSION

Based on the findings of the current study, salivary CRP can be considered a biomarker for the early diagnosis of neonatal sepsis, while no statistical values for salivary IL-18 were detected. Due to the significance of neonatal sepsis, further evaluations are strongly recommended.

Experience in the diagnosis of group B Streptococcus infections in pregnant women and newborns in a perinatal center

Serogroup B streptococci (Streptococcus agalactiae) are one of the main etiological agents responsible for the occurrence of severe perinatal infections in both postpartum women and newborns. The experience of microbiological diagnostics of infections caused by streptococcus serogroup B (GBS) according to the data of the microbiological laboratory of the perinatal center is generalized. In the study of biomaterial from patients, the proportion of positive cultures of Streptococcus agalactiae was 2.2% in cervical samples, 8.8% in vaginal contents, 6.6%; 2.8% and 0.7% in amniotic fluid, placenta and urine, respectively. In 57% of cases, GBS was released at a concentration of more than 5 lg / ml and in 73% of cases as part of polymicrobial associations with other opportunistic microorganisms. In the biomaterial from newborns, GBS was found in 2.5% of positive findings in blood samples, 4.6% in tracheobronchial lavages and 2.7% in detachable skin of the armpit when taking material immediately after childbirth and 1, 1% and 0.7%, respectively, during examination in the second stage of nursing. 5 cases of GBS isolation in newborns ended in early neonatal mortality with definitive diagnoses of congenital pneumonia and IUI of newborns, while there was only partial coincidence of the results of microbiological studies of the genital tract of the mother and biomaterials from the newborn. Relatively frequent findings of GBS in newborns of the high-risk group in intensive care unit indicate intrauterine infection with this pathogen. The examination of smears from the cervical canal is not informative in relation toGBS infection in comparison with the examination of the vaginal contents and recto-vaginal smears. The results of the introduction of microbiological screening and its effectiveness in real practice to prevent the development of early and late forms of GBS infections in newborns require further analysis.

A Prospective Study on Neonatal Sepsis in a Tertiary Hospital, Nepal

About 20 % of neonates develop sepsis and among them approximately 1% die due to sepsis-related causes. Bacterial pathogens are the commonest cause of neonatal sepsis which is either early-onset (<72 hours of age) or late-onset (>72 hours). Little is known about the epidemiology and antimicrobial susceptibility pattern of sepsis causing bacterial pathogens in Nepal. A prospective study was carried out among neonates suspected to have sepsis and admitted to Tribhuwan University Teaching Hospital from January to December 2016. Clinical suspicion of sepsis was made based on clinical findings and laboratory parameters, later confirmed by isolation of organisms in blood culture. Drug resistance pattern of Gram-positive and Gram-negative bacteria were studied by standard methods. Meropenem resistant Gram-negative bacteria were processed for the detection of β-lactamases and resistant genes were detected by X-pert Carba-R (Cepheid) Assays. Of 372 neonates with clinically suspected sepsis, 132 (35.4%) had blood culture positivity, with 47% early-onset and 53% late-onset sepsis. Coagulase-negative Staphylococcus aureus (CONS) was the most common (37.9%) etiological agent followed by Klebsiella pneumoniae (12.9%). Of all 132 isolates, 81 (61.3%) were Gram-positive of which 22 (27.2%) were multi-drug resistant (MDR), three (3.7%) were methicillin-resistant S. aureus (MRSA), and 14 (17.2%) were methicillin-resistant CoNS; and 50 (37.8%) were Gram-negative of which 26 (52%) were MDR and 29 (58%) were resistant to β-lactamases. The blaKPC gene was detected in four isolates of K. pneumoniae, two of E. coli, one ABC (Acinetobacter baumanii complex), and one Enterobacter aerogenes whereas blaNDM gene was detected in one isolate of K. pneumoniae, two of E. coli, two Pseudomonas aeruginosa, one Acinetobacter baumanii complex, and one Enterobacter aerogenes. Overall mortality due to sepsis-related causes was 7.6% (10 of 132). One-third of clinically suspected neonatal sepsis cases were culture positive. Late-onset sepsis was more common than early onset. CoNS was the predominant bacterial isolate followed by Klebsiella pneumoniae, with high rates of multi-drug resistance.

Clinical and immunological aspects of microRNAs in neonatal sepsis

Neonatal sepsis constitutes a highly relevant public health challenge and is the most common cause of infant morbidity and mortality worldwide. Recent studies have demonstrated that during infection epigenetic changes may occur leading to reprogramming of gene expression. Post-transcriptional regulation by short non-coding RNAs (e.g., microRNAs) have recently acquired special relevance because of their role in the regulation of the pathophysiology of sepsis and their potential clinical use as biomarkers. ~22-nucleotide of microRNAs are not only involved in regulating multiple relevant cellular and molecular functions, such as immune cell function and inflammatory response, but have also been proposed as good candidates as biomarkers in sepsis. Nevertheless, establishing clinical practice guidelines based on microRNA patterns as biomarkers for diagnosis and prognosis in neonatal sepsis has yet to be achieved. Given their differential expression across tissues in neonates, the release of specific microRNAs to blood and their expression pattern can differ compared to sepsis in adult patients. Further in-depth research is necessary to fully understand the biological relevance of microRNAs and assess their potential use in clinical settings. This review provides a general overview of microRNAs, their structure, function and biogenesis before exploring their potential clinical interest as diagnostic and prognostic biomarkers of neonatal sepsis. An important part of the review is focused on immune and inflammatory aspects of selected microRNAs that may become biomarkers for clinical use and therapeutic intervention.