Immunomodulation to Prevent or Treat Neonatal Sepsis: Past, Present, and Future

DDIT4L regulates mitochondrial and innate immune activities in early life

Pattern recognition receptor responses are profoundly attenuated before the third trimester of gestation in the relatively low-oxygen human fetal environment. However, the mechanisms regulating these responses are uncharacterized. Herein, genome-wide transcription and functional metabolic experiments in primary neonatal monocytes linked the negative mTOR regulator DDIT4L to metabolic stress, cellular bioenergetics, and innate immune activity. Using genetically engineered monocytic U937 cells, we confirmed that DDIT4L overexpression altered mitochondrial dynamics, suppressing their activity, and blunted LPS-induced cytokine responses. We also showed that monocyte mitochondrial function is more restrictive in earlier gestation, resembling the phenotype of DDIT4L-overexpressing U937 cells. Gene expression analyses in neonatal granulocytes and lung macrophages in preterm infants confirmed upregulation of the DDIT4L gene in the early postnatal period and also suggested a potential protective role against inflammation-associated chronic neonatal lung disease. Taken together, these data show that DDIT4L regulates mitochondrial activity and provide what we believe to be the first direct evidence for its potential role supressing innate immune activity in myeloid cells during development.

Development of a new treatment for preterm birth complications using amniotic fluid stem cell therapy

This paper describes the current status of studies and clinical trials on the use of mesenchymal stem cells (MSCs) and amniotic fluid stem cells (AFSCs) for complications of preterm birth (PTB), an urgent issue in the perinatal field. PTB is a serious challenge in clinical medicine that is increasing globally, and effective control of its complications is necessary for newborns' subsequent long life. Classical treatments are inadequate, and many patients have PTB complications. A growing body of evidence provided by translational medicine and others indicates that MSCs, and among them, the readily available AFSCs, may be useful in treating PTB complications. AFSCs are the only MSCs available prenatally and are known to be highly anti-inflammatory and tissue-protective and do not form tumors when transplanted. Furthermore, because they are derived from the amniotic fluid, a medical waste product, no ethical issues are involved. AFSCs are an ideal cell resource for MSC therapy in neonates. This paper targets the brain, lungs, and intestines, which are the vital organs most likely to be damaged by PTB complications. The evidence to date and future prospects with MSCs and AFSCs for these organs are described.

Neutrophil extracellular trap inhibition improves survival in neonatal mouse infectious peritonitis

BACKGROUND

Treatment of neonatal peritonitis and sepsis is challenging. Following infection, neutrophils elaborate neutrophil extracellular traps (NETs)-extracellular lattices of decondensed chromatin decorated with antimicrobial proteins. NETs, however, can augment pathogenic inflammation causing collateral damage. We hypothesized that NET inhibition would improve survival in experimental neonatal infectious peritonitis.

METHODS

We induced peritonitis in 7 to 10-day-old mice by intraperitoneal injection with cecal slurry. We targeted NETs by treating mice with neonatal NET-Inhibitory Factor (nNIF), an endogenous NET-inhibitor; Cl-amidine, a PAD4 inhibitor; DNase I, a NET degrading enzyme, or meropenem (an antibiotic). We determined peritoneal NET and cytokine levels and circulating platelet-neutrophil aggregates. Survival from peritonitis was followed for 6 days.

RESULTS

nNIF, Cl-amidine, and DNase I decreased peritoneal NET formation and inflammatory cytokine levels at 24 h compared to controls. nNIF, Cl-amidine, and DNase I decreased circulating platelet-neutrophil aggregates, and NET-targeting treatments significantly increased survival from infectious peritonitis compared to controls. Finally, nNIF administration significantly improved survival in mice treated with sub-optimal doses of meropenem even when treatment was delayed until 2 h after peritonitis induction.

CONCLUSIONS

NET inhibition improves survival in experimental neonatal infectious peritonitis, suggesting that NETs participate pathogenically in neonatal peritonitis and sepsis.

IMPACT

1. Neutrophil extracellular trap formation participates pathogenically in experimental neonatal infectious peritonitis. 2. NET-targeting strategies improve outcomes in a translational model of neonatal infectious peritonitis. 3. NET inhibition represents a potential target for drug development in neonatal sepsis and infectious peritonitis.

Dual inhibition of complement C5 and CD14 attenuates inflammation in a cord blood model

BACKGROUND

Escherichia coli and Group B streptococci (GBS) are the main causes of neonatal early-onset sepsis (EOS). Despite antibiotic therapy, EOS is associated with high morbidity and mortality. Dual inhibition of complement C5 and the Toll-like receptor co-factor CD14 has in animal studies been a promising novel therapy for sepsis.

METHODS

Whole blood was collected from the umbilical cord after caesarean section (n = 30). Blood was anti-coagulated with lepirudin. C5 inhibitor (eculizumab) and anti-CD14 was added 8 min prior to, or 15 and 30 min after adding E. coli or GBS. Total bacterial incubation time was 120 min (n = 16) and 240 min (n = 14). Cytokines and the terminal complement complex (TCC) were measured using multiplex technology and ELISA.

RESULTS

Dual inhibition significantly attenuated TCC formation by 25-79% when adding inhibitors with up to 30 min delay in both E. coli- and GBS-induced inflammation. TNF, IL-6 and IL-8 plasma concentration were significantly reduced by 28-87% in E. coli-induced inflammation when adding inhibitors with up to 30 min delay. The dual inhibition did not significantly reduce TNF, IL-6 and IL-8 plasma concentration in GBS-induced inflammation.

CONCLUSION

Dual inhibition of C5 and CD14 holds promise as a potential future treatment for severe neonatal EOS.

IMPACT

Neonatal sepsis can cause severe host inflammation with high morbidity and mortality, but there are still no effective adjunctive immunologic interventions available. Adding CD14 and complement C5 inhibitors up to 30 min after incubation of E. coli or Group B streptococci in a human umbilical cord blood model significantly reduced complement activation and cytokine release. Dual inhibition of C5 and CD14 is a potential future therapy to modulate systemic inflammation in severe cases of neonatal sepsis.

Updates in Late-Onset Sepsis: Risk Assessment, Therapy, and Outcomes

Neonatal late-onset sepsis (LOS) continues to threaten morbidity and mortality in the NICU and poses ongoing diagnostic and therapeutic challenges. Early recognition of clinical signs, rapid evaluation, and prompt initiation of treatment are critical to prevent life-threatening deterioration. Preterm infants-born at ever-decreasing gestational ages-are at particularly high risk for life-long morbidities and death. This changing NICU population necessitates continual reassessments of diagnostic and preventive measures and evidence-based treatment for LOS. The clinical presentation of LOS is varied and nonspecific. Despite ongoing research, reliable, specific laboratory biomarkers facilitating early diagnosis are lacking. These limitations drive an ongoing practice of liberal initiation of empiric antibiotics among infants with suspected LOS. Subsequent promotion of multidrug-resistant microorganisms threatens the future of antimicrobial therapy and puts preterm and chronically ill infants at even higher risk of nosocomial infection. Efforts to identify adjunctive therapies counteracting sepsis-driven hyperinflammation and sepsis-related functional immunosuppression are ongoing. However, most approaches have either failed to improve LOS prognosis or are not yet ready for clinical application. This article provides an overview of the epidemiology, risk factors, diagnostic tools, and treatment options of LOS in the context of increasing numbers of extremely preterm infants. It addresses the question of whether LOS could be identified earlier and more precisely to allow for earlier and more targeted therapy and discusses rational approaches to antibiotic therapy to avoid overuse. Finally, this review elucidates the necessity of long-term follow-up of infants with a history of LOS.

Predictors of Death in Patients with Neonatal Sepsis in a Peruvian Hospital

Reducing neonatal mortality is a global challenge. This study’s objective was to determine the predictors of mortality in patients with neonatal sepsis. The study was a retrospective cohort study in a Peruvian hospital from January 2014 to April 2022. Neonates diagnosed with sepsis were included. To find predictors of mortality, we used Cox proportional regression models. We evaluated 288 neonates with sepsis; the median birth weight and hospitalization time were 3270 g and seven days, respectively. During follow-up, 18.4% did not survive, and the most common complications were jaundice (35.42%), respiratory distress syndrome (29.51%), and septic shock (12.5%). The most isolated bacteria were Klebsiella pneumoniae. The risk factors associated with higher mortality were prematurity (aHR = 13.92; 95% CI: 1.71−113.51), platelets <150,000 (aHR = 3.64; 1.22−10.88), creatinine greater than 1.10 (aHR = 3.03; 1.09−8.45), septic shock (aHR = 4.41; 2.23−8.74), and admission to IMV (aHR = 5.61; 1.86−16.88), On the other hand, breastfeeding was associated with a lower risk of death (aHR = 0.25; 0.13−0.48). In conclusion, we report a high incidence of death and identify clinical (prematurity, septic shock, admission to IMV) and laboratory characteristics (elevated creatinine and thrombocytopenia) associated with higher mortality in patients with neonatal sepsis. Breastfeeding was a factor associated with survival in these patients.

Neonatal Antibiotic Treatment Can Affect Stool Pattern and Oral Tolerance in Preterm Infants

Preterm neonates are at high risk of infectious and inflammatory diseases which require antibiotic treatment. Antibiotics influence neonatal gut microbiome development, and intestinal dysbiosis has been associated with delayed gastrointestinal transit. Neonates who take less time to pass meconium have a better tolerance to enteral feeding. We analyzed the effect of neonatal antibiotic treatment on the stool pattern and oral tolerance in 106 preterm infants < 33 weeks gestational age. Neonates were classified in 3 groups according to neonatal antibiotic (ABT) treatment days: no antibiotics, 3−7 d ABT, and ≥8 d ABT. Preterm infants from the ≥8 d ABT group took longer to pass meconium and to start green and yellow stools, took longer to reach 100 and 150 mL/kg/day, and reached reduced volumes in enteral feeds at day of life 14 and 28 than infants from no ABT and 3−7 d ABT groups. Multiple linear regression models showed that neonatal antibiotic treatment, birth weight, invasive mechanical ventilation, surfactant, enteral feeding start day, neonatal parenteral nutrition, and neonatal fasting days are associated with the stool pattern and oral tolerance in preterm infants.

Antimicrobial utilization in very-low-birth-weight infants: association with probiotic use

OBJECTIVE

To examine the association between probiotic use and antimicrobial utilization.

STUDY DESIGN

We retrospectively evaluated very-low-birth-weight (VLBW) infants admitted to tertiary neonatal intensive care units in Canada between 2014 and 2019. Our outcome was antimicrobial utilization rate (AUR) defined as number of days of antimicrobial exposure per 1000 patient-days.

RESULT

Of 16,223 eligible infants, 7279 (45%) received probiotics. Probiotic use rate increased from 10% in 2014 to 68% in 2019. The AUR was significantly lower in infants who received probiotics vs those who did not (107 vs 129 per 1000 patient-days, aRR = 0.89, 95% CI [0.81, 0.98]). Among 13,305 infants without culture-proven sepsis or necrotizing enterocolitis ≥Stage 2, 5931 (45%) received probiotics. Median AUR was significantly lower in the probiotic vs the no-probiotic group (78 vs 97 per 1000 patient-days, aRR = 0.85, 95% CI [0.74, 0.97]).

CONCLUSION

Probiotic use was associated with a significant reduction in AUR among VLBW infants.

Zinc Supplementation in Preterm Neonates with Late-Onset Sepsis: Is It Beneficial?

OBJECTIVE

Neonatal sepsis (NS) is a serious neonatal disease. The aim of this study was to detect the role of zinc (Zn) supplementation in preterm neonates with late-onset sepsis (LOS).

STUDY DESIGN

A prospective randomized clinical trial study which was done at Tanta University Hospital from August 2016 to March 2018 on 180 preterm neonates with LOS. The studied neonates were divided into two groups: group 1 (90 neonates), which received Zn and antibiotics, and group 2 (90 neonates), which received antibiotics and placebo. In group 1, the neonates received 1.4 mg elemental Zn/kg/d orally for 10 days. Sepsis score, C-reactive protein (CRP), and procalcitonin (PCT) were done for both groups.

RESULTS

As regards sepsis score, it showed that before beginning the treatment, there were 85 and 84 neonates who had high probable sepsis (HPS) in intervention and control groups, respectively, and this revealed nonstatistically significant difference (non-SSD) between both groups (p-value is 0.756) and after 10 days of treatment, there were 1 and 4 neonates who had HPS in intervention and control group, respectively, and this revealed SSD between both groups (p-value is 0.045*). As regards CRP and PCT, the results showed that before beginning the treatment, the mean ± standard deviation (SD) of CRP and PCT were 39.4 ± 10.1 mg/L and 5.2 + 1.8 ng/mL, respectively, in intervention group, while it was 39.6 + 9.9 mg/L and 5.1 + 1.9 ng/mL, respectively, in control group and this revealed non-SSD between both groups (p-value is 0.893 and 0.717, respectively) and after 10 days of treatment, the mean ± SD of CRP and PCT were 5.3 ± 1.8 mg/L and 0.39 ± 0.13 ng/mL, respectively, in intervention group and 6.1 + 2 mg/L and 0.61 + 0.22 ng/mL, respectively, in control group and this revealed SSD between both groups (p-value is 0.008* and 0.044*, respectively).

CONCLUSION

Zn supplementation in preterm neonates with LOS is beneficial in improving the clinical and laboratory finding.

RECOMMENDATION

Zn supplementation for preterm neonates with LOS.

KEY POINTS

· NS is a serious neonatal disease.. · Preterm neonates are more liable to infections.. · Zn supplementation in preterm neonates with LOS is beneficial in improving the condition..

Pharmacokinetics of Clavulanic Acid in the Pediatric Population: A Systematic Literature Review

Background and Objective

Clavulanic acid is a commonly used β-lactam inhibitor in pediatrics for a variety of infections. Clear insight into its mode of action is lacking, however, and a target has not been identified. The dosing of clavulanic acid is currently based on that of the partner drug (amoxicillin or ticarcillin). Still, proper dosing of the compound is needed because clavulanic acid has been associated with adverse effects. In this systematic review, we aim to describe the current literature on the pharmacokinetics of clavulanic acid in the pediatric population

Methods

We performed a systematic search in MEDLINE, Embase.com, Cochrane Central, Google Scholar, and Web of Science. We included all published studies reporting pharmacokinetic data on clavulanic acid in neonates and children 0–18 years of age.

Results

The search resulted in 18 original studies that met the inclusion criteria. In general, the variation in drug exposure was large, which can be partly explained by differences in disease state, route of administration, or age. Unfortunately, the studies’ limited background information hampered in-depth assessment of the observed variability.

Conclusion

The pharmacokinetics of clavulanic acid in pediatric patients is highly variable, similar to reports in adults, but more pronounced. Significant knowledge gaps remain with regard to the population-specific explanation for this variability. Model-based pharmacokinetic studies that address both maturational and disease-specific changes in the pediatric population are therefore needed. Furthermore, additional pharmacodynamic studies are needed to define a clear target. The combined outcomes will eventually lead to pharmacokinetic-pharmacodynamic modeling of clavulanic acid and targeted exposure.

Clinical Trial Registration

PROSPERO CRD42020137253.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-022-01116-3.

Look Who's Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis

Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.

Zinc Supplementation and the Prevention and Treatment of Sepsis in Young Infants: A Systematic Review and Meta-Analysis

BACKGROUND

Prematurity and low birth weight are major risk factors for neonatal sepsis. Zinc supplements have been previously shown to be beneficial in pregnancy and small for gestational age birth outcomes. There is sparse information, however, on the potential benefits of zinc supplementation to prevent or treat serious infections in this age group.

OBJECTIVE

The aim of this study was to assess the efficacy of preventive and therapeutic zinc supplementation in young infant (<4 months) sepsis.

METHODS

MEDLINE, Cochrane CENTRAL, and other databases were searched from inception until 18 June 2021. Studies assessing preventive and therapeutic zinc supplementation in young infants in relation to incidence and outcomes of suspected sepsis were included. Meta-analyses of pooled effects were calculated for sepsis-related outcomes.

RESULTS

Nine randomized controlled trials involving 2,553 infants were included. Six studies reported therapeutic efficacy, whereas 3 evaluated preventive benefits of zinc supplementation. Preventive studies suggest a protective effect of zinc supplementation on neonatal mortality rate (NMR) (risk ratio (RR) 0.28; 95% CI 0.12-0.67, LOW certainty), but with no effect on the incidence of sepsis, both in preterm neonates. Among young infants, therapeutic zinc was associated with significant reductions in treatment failure (RR 0.61; 95% CI 0.44-0.85; MODERATE certainty) and further subgroup analysis showing significant reduction in infant mortality rate with 3 mg/kg/twice a day dosage only (RR 0.49; 95% CI 0.27-0.87, LOW certainty). Therapeutic zinc supplementation in neonates did not show any effect on hospital stay or NMR.

CONCLUSION

Zinc supplementation could potentially reduce mortality and treatment failure in young infants but has no noteworthy influence on hospital stay and in the prevention of sepsis. Further studies with larger sample sizes are needed to confirm the direction and magnitude of effects if any.

Knowledge gaps in late-onset neonatal sepsis in preterm neonates: a roadmap for future research

Late-onset neonatal sepsis (LONS) remains an important threat to the health of preterm neonates in the neonatal intensive care unit. Strategies to optimize care for preterm neonates with LONS are likely to improve survival and long-term neurocognitive outcomes. However, many important questions on how to improve the prevention, early detection, and therapy for LONS in preterm neonates remain unanswered. This review identifies important knowledge gaps in the management of LONS and describe possible methods and technologies that can be used to resolve these knowledge gaps. The availability of computational medicine and hypothesis-free-omics approaches give way to building bedside feedback tools to guide clinicians in personalized management of LONS. Despite advances in technology, implementation in clinical practice is largely lacking although such tools would help clinicians to optimize many aspects of the management of LONS. We outline which steps are needed to get possible research findings implemented on the neonatal intensive care unit and provide a roadmap for future research initiatives. IMPACT: This review identifies knowledge gaps in prevention, early detection, antibiotic, and additional therapy of late-onset neonatal sepsis in preterm neonates and provides a roadmap for future research efforts. Research opportunities are addressed, which could provide the means to fill knowledge gaps and the steps that need to be made before possible clinical use. Methods to personalize medicine and technologies feasible for bedside clinical use are described.

Diversity of the T cell receptor β chain complementarity-determining region 3 in peripheral blood of neonates with sepsis: an analysis based on immune repertoire sequencing

OBJECTIVES

To investigate the diversity of peripheral blood T cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) based on immune repertoire sequencing in neonates with sepsis and the possible pathogenesis of neonatal sepsis.

METHODS

A total of 12 neonates with sepsis were enrolled as the case group, and 9 healthy full-term infants, matched for gestational age, birth weight, and age, were enrolled as the control group. Omega nucleic acid purification kit (SQ blood DNA Kit II) was used to extract DNA from peripheral blood samples, TCR β chain CDR3 was amplified by multiplex PCR, and then high-throughput sequencing was performed for the products to analyze the diversity of TCR β chain CDR3 and the difference in expression.

RESULTS

The length and type of TCR β chain CDR3 were similar between the case and control groups, and Gaussian distribution was observed in both groups. With D50 and Shannon-Wiener index as the evaluation indices for diversity, the case group had a significantly lower diversity of TCR β chain CDR3 than the control group (P<0.05). The frequency of 48 genes in TCR β chain V segment was compared, and the results showed that compared with the control group, the case group had significantly higher frequencies of TRBV10-3, TRBV2, and TRBV20-1 (P<0.05). The frequency of 13 genes in TCR β chain J segment were compared, and the results showed that compared with the control group, the case group had significantly higher frequencies of TRBJ2-3, TRBJ2-5, and TRBJ2-7 (P<0.05).

CONCLUSIONS

There is a significant change in the diversity of TCR β chain CDR3 in the peripheral blood of neonates with sepsis, suggesting that it might be associated with the immune pathogenesis of neonatal sepsis.

The possible effect of pentoxifylline on development and severity of retinopathy of prematurity

BACKGROUND AND AIM

Retinopathy of prematurity (ROP) is the major ocular problem of preterm infants that occurs with abnormal proliferation of immature retinal vessels. Although pentoxifylline (PTX) was reported to inhibit vasculogenesis and neovascularization in experimental studies, there is no clinical data about the effects of PTX treatment on the development and severity of ROP. This clinical study aimed to investigate the possible effects of PTX on the development of ROP.

MATERIALS AND METHODS

A single-centre retrospective study was conducted including preterm infants who were hospitalised in the neonatal intensive care unit between 2015-2017 years. Infants were divided into two groups in terms of PTX administration for adjuvant therapy, as PTX and non-PTX groups.

RESULTS

A total of 211 infants were included in the study [gestational age 29 (27-31) weeks, birth weight 1140 (960-1340) g]. From these, 97 infants (46%) were given PTX treatment. The two groups were similar in terms of demographic data and baseline clinical characteristics. Any stage of ROP was detected in 47.4% of infants in the PTX group, which was significantly higher than those in the non-PTX group (27.2%) (p = 0.002). The incidence of advanced-stage ROP in the PTX group (10.3%) was also higher than in the non-PTX group (2.6%) (p = 0.021). Repeated usage of PTX was not found to be related to the development of ROP (p = 0.059). The time of PTX administration was similar between the ROP and no-ROP groups (median; one vs one week, p = 0.825). Surfactant therapy, duration of hospital stay, and PTX treatment were found as significant risk factors for ROP in the logistic regression analysis.

CONCLUSIONS

In contrast to the experimental studies and also promising results of PTX treatment in some neonatal morbidities, it may be associated with increased incidence and stage of ROP.

The potential for Lactoferrin to reduce SARS-CoV-2 induced cytokine storm

The COVID-19 pandemic is a serious global health threat caused by severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2). Symptoms of COVID-19 are highly variable with common hyperactivity of immune responses known as a "cytokine storm". In fact, this massive release of inflammatory cytokines into in the pulmonary alveolar structure is a main cause of mortality during COVID-19 infection. Current management of COVID-19 is supportive and there is no common clinical protocol applied to suppress this pathological state. Lactoferrin (LF), an iron binding protein, is a first line defense protein that is present in neutrophils and excretory fluids of all mammals, and is well recognized for its role in maturation and regulation of immune system function. Also, due to its ability to sequester free iron, LF is known to protect against insult-induced oxidative stress and subsequent "cytokine storm" that results in dramatic necrosis within the affected tissue. Review of the literature strongly suggests utility of LF to silence the "cytokine storm", giving credence to both prophylactic and therapeutic approaches towards combating COVID-19 infection.

Detailed nursing intervention on neonatal septicemia can improve the clinical symptoms of children and reduce the inflammatory reaction

OBJECTIVE

To explore the application effect of detailed nursing intervention in neonatal septicemia.

METHODS

Altogether 60 neonates of neonatal septicemia admitted to our hospital from November 2019 to October 2020 were selected as the research participants, and all the children have received routine treatment, among which 30 neonates received routine nursing intervention as the regular group, and the remaining 30 received detailed nursing intervention as the detail group. The clinical effects, improvement of clinical symptoms, length of stay, and guardian satisfaction were compared, and the levels of serum inflammatory factors (TNF-α, IL-6 and IL-17) and immune function indicators (CD4+, CD8+) before and after nursing intervention were detected.

RESULTS

The total effective rate in the detail group was higher than that in the regular group (P < 0.05). Compared with the regular group, the temperature stabilization time, blood culture turning negative time, improvement time of milk rejection and hospital stay in the detail group were significantly shortened (P < 0.05). The guardian satisfaction score in the detail group was higher than that in the regular group (P < 0.05). After nursing, the levels of TNF-α, IL-6 and IL-17 decreased in both groups, and the levels of these three in the detail group were lower than those in the regular group (P < 0.05). After nursing, CD4+/CD8+ of children in both groups increased, and CD4+/CD8+ in the detail group and regular group were higher than those in the regular group (P < 0.05).

CONCLUSION

The adoption of detailed nursing modes in the treatment of neonatal septicemia can further improve the treatment effect, shorten the hospital stay and the improvement time of clinical symptoms, reduce the incidence of complications, improve the nursing satisfaction of guardians, reduce the inflammation of the body and improve the immune function of the body.

Bioactive proteins in bovine colostrum and effects of heating, drying and irradiation

Bovine colostrum (BC) contains bioactive proteins, such as immunoglobulin G (IgG), lactoferrin (LF) and lactoperoxidase (LP). BC was subjected to low-temperature, long-time pasteurization (LTLT, 63 °C, 30 min) or high-temperature, short-time pasteurization (HTST, 72 °C, 15 s) and spray-drying (SD), with or without γ-irradiation (GI, ∼14 kGy) to remove microbial contamination. Relative to unpasteurized liquid BC, SD plus GI increased protein denaturation by 6 and 11%, respectively, increasing to 19 and 27% after LTLT and to 48% after HTST, with no further effects after GI (all P < 0.05). LTLT, without or with GI, resulted in 15 or 29% denaturation of IgG, compared with non-pasteurized BC, and 34 or 58% for HTST treatment (all P < 0.05, except LTLT without GI). For IgG, only GI, not SD or LTLT, increased denaturation (30-38%, P < 0.05) but HTST increased denaturation to 40%, with further increases after GI (60%, P < 0.05). LTLT and HTST reduced LP levels (56 and 81% respectively) and LTLT reduced LF levels (21%), especially together with GI (47%, P < 0.05). Denaturation of BSA, β-LgA, β-LgB and α-La were similar to IgG. Methionine, a protective amino acid against free oxygen radicals, was oxidised by LTLT + GI (P < 0.05) while LTLT and HTST had no effect. Many anti-inflammatory proteins, including serpin anti-proteinases were highly sensitive to HTST and GI but preserved after LTLT pasteurization. LTLT, followed by SD is an optimal processing technique preserving bioactive proteins when powdered BC is used as a diet supplement for sensitive patients.

Detection of Volatile Organic Compounds as Potential Novel Biomarkers for Chorioamnionitis - Proof of Experimental Models

Background: Histologic chorioamnionitis is only diagnosed postnatally which prevents interventions. We hypothesized that volatile organic compounds (VOCs) in the amniotic fluid might be useful biomarkers for chorioamnionitis and that VOC profiles differ between amnionitis of different origins. Methods: Time-mated ewes received intra-amniotic injections of media or saline (controls), or live Ureaplasma parvum serovar 3 (Up) 14, 7 or 3d prior to c-section at day 124 gestational age (GA). 100 μg recombinant ovine IL-1α was instilled at 7, 3 or 1d prior to delivery. Headspace VOC profiles were measured from amniotic fluids at birth using ion mobility spectrometer coupled with multi-capillary columns. Results: 127 VOC peaks were identified. 27 VOCs differed between samples from controls and Up- or IL-1α induced amnionitis. The best discrimination between amnionitis by Up vs. IL-1α was reached by 2-methylpentane, with a sensitivity/specificity of 96/95% and a positive predictive value/negative predictive values of 96 and 95%. The concentration of 2-methylpentane in VOCs peaked 7d after intra-amniotic instillation of Up. Discussion: We established a novel method to study headspace VOC profiles of amniotic fluids. VOC profiles may be a useful tool to detect and to assess the duration of amnionitis induced by Up. 2-methylpentane was previously described in the exhalate of women with pre-eclampsia and might be a volatile biomarker for amnionitis. Amniotic fluids analyzed by ion mobility spectrometry coupled with multi-capillary columns may provide bedside diagnosis of amnionitis and understanding inflammatory mechanisms during pregnancy.

Stratified Management for Bacterial Infections in Late Preterm and Term Neonates: Current Strategies and Future Opportunities Toward Precision Medicine

Bacterial infections remain a major cause of morbidity and mortality in the neonatal period. Therefore, many neonates, including late preterm and term neonates, are exposed to antibiotics in the first weeks of life. Data on the importance of inter-individual differences and disease signatures are accumulating. Differences that may potentially influence treatment requirement and success rate. However, currently, many neonates are treated following a "one size fits all" approach, based on general protocols and standard antibiotic treatment regimens. Precision medicine has emerged in the last years and is perceived as a new, holistic, way of stratifying patients based on large-scale data including patient characteristics and disease specific features. Specific to sepsis, differences in disease susceptibility, disease severity, immune response and pharmacokinetics and -dynamics can be used for the development of treatment algorithms helping clinicians decide when and how to treat a specific patient or a specific subpopulation. In this review, we highlight the current and future developments that could allow transition to a more precise manner of antibiotic treatment in late preterm and term neonates, and propose a research agenda toward precision medicine for neonatal bacterial infections.

A Neonatal Murine Escherichia coli Sepsis Model Demonstrates That Adjunctive Pentoxifylline Enhances the Ratio of Anti- vs. Pro-inflammatory Cytokines in Blood and Organ Tissues

Introduction: Neonatal sepsis triggers an inflammatory response that contributes to mortality and multiple organ injury. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses pro-inflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that administration of PTX in addition to antibiotics decreases live bacteria-induced pro-inflammatory and/or enhances anti-inflammatory cytokine production in septic neonatal mice without augmenting bacterial growth.

Methods: Newborn C57BL/6J mice (< 24 h old) were injected intravenously with 10⁵ colony forming units (CFUs)/g weight of a bioluminescent derivative of the encapsulated clinical isolate Escherichia coli O18:K1. Adequacy of intravenous injections was validated using in vivo bioluminescence imaging and Evans blue. Pups were treated with gentamicin (GENT), PTX, (GENT + PTX) or saline at 0, 1.5, or 4 h after sepsis initiation, and euthanized after an additional 4 h. CFUs and cytokines were measured from blood and homogenized organ tissues.

Results: GENT alone inhibited bacterial growth, IL-1β, and IL-6 production in blood and organs. Addition of PTX to GENT profoundly inhibited E. coli-induced TNF and enhanced IL-10 in blood of newborn mice at all timepoints, whereas it primarily upregulated IL-10 production in peripheral organs (lung, spleen, brain). PTX, whether alone or adjunctive to GENT, did not increase microbial colony counts in blood and organs.

Conclusion: Addition of PTX to antibiotics in murine neonatal E. coli sepsis promoted an anti-inflammatory milieu through inhibition of plasma TNF and enhancement of IL-10 production in plasma and organs without increasing bacterial growth, supporting its utility as a potential adjunctive agent for newborn sepsis.

Intravenous pentoxifylline is well tolerated in critically ill preterm infants with sepsis or necrotizing enterocolitis

Pentoxifylline (PTX) is a candidate adjuvant medication for the treatment of sepsis and necrotizing enterocolitis in preterm infants. There is only limited data on safety and compatibility with other commonly used intravenous medications. This retrospective single-center study of 198 preterm infants (September 2012-September 2018) was performed at a level IV neonatal intensive care unit. Electronic data of all preterm infants who received pentoxifylline for sepsis or necrotizing were extracted from routine databases. We analyzed a total of 1081 PTX treatment days from 217 treatment episodes in 198 preterm infants (mean gestational age 27 weeks; mean birth weight 1060 g). At a mean daily dose of 28 mg/kg, no clinically relevant side effects were observed. PTX therapy was not associated with clinically significant changes of blood biochemistry and hematology parameters. Concomitant infusion of PTX with other common NICU medications was well tolerated, and there was no evidence of incompatibility.Conclusion: Intravenous PTX is compatible with standard NICU drugs and well tolerated in critically ill preterm infants. What is Know: •Currently, there are no evidence-based adjuvant medications available that target the harmful inflammatory host response in neonatal sepsis or necrotizing enterocolitis. •Pentoxifylline (PTX) is a candidate adjuvant medication for the treatment of sepsis and necrotizing enterocolitis in preterm infants; however, safety data are rare and PTX is currently used off-label. What is New: •Here we report on our experience in the pragmatic routine use of PTX as adjuvant therapy in 198 preterm infants with sepsis or NEC. •Concomitant infusion of PTX with other common NICU medications was well tolerated, and there was no evidence of incompatibility. No clinically relevant side effects were observed.

The fetal inflammatory response syndrome: the origins of a concept, pathophysiology, diagnosis, and obstetrical implications

The fetus can deploy a local or systemic inflammatory response when exposed to microorganisms or, alternatively, to non-infection-related stimuli (e.g., danger signals or alarmins). The term "Fetal Inflammatory Response Syndrome" (FIRS) was coined to describe a condition characterized by evidence of a systemic inflammatory response, frequently a result of the activation of the innate limb of the immune response. FIRS can be diagnosed by an increased concentration of umbilical cord plasma or serum acute phase reactants such as C-reactive protein or cytokines (e.g., interleukin-6). Pathologic evidence of a systemic fetal inflammatory response indicates the presence of funisitis or chorionic vasculitis. FIRS was first described in patients at risk for intraamniotic infection who presented preterm labor with intact membranes or preterm prelabor rupture of the membranes. However, FIRS can also be observed in patients with sterile intra-amniotic inflammation, alloimmunization (e.g., Rh disease), and active autoimmune disorders. Neonates born with FIRS have a higher rate of complications, such as early-onset neonatal sepsis, intraventricular hemorrhage, periventricular leukomalacia, and death, than those born without FIRS. Survivors are at risk for long-term sequelae that may include bronchopulmonary dysplasia, neurodevelopmental disorders, such as cerebral palsy, retinopathy of prematurity, and sensorineuronal hearing loss. Experimental FIRS can be induced by intra-amniotic administration of bacteria, microbial products (such as endotoxin), or inflammatory cytokines (such as interleukin-1), and animal models have provided important insights about the mechanisms responsible for multiple organ involvement and dysfunction. A systemic fetal inflammatory response is thought to be adaptive, but, on occasion, may become dysregulated whereby a fetal cytokine storm ensues and can lead to multiple organ dysfunction and even fetal death if delivery does not occur ("rescued by birth"). Thus, the onset of preterm labor in this context can be considered to have survival value. The evidence so far suggests that FIRS may compound the effects of immaturity and neonatal inflammation, thus increasing the risk of neonatal complications and long-term morbidity. Modulation of a dysregulated fetal inflammatory response by the administration of antimicrobial agents, anti-inflammatory agents, or cell-based therapy holds promise to reduce infant morbidity and mortality.

Prophylactic therapy with human amniotic fluid stem cells improved survival in a rat model of lipopolysaccharide-induced neonatal sepsis through immunomodulation via aggregates with peritoneal macrophages

Background

Despite recent advances in neonatal care, sepsis remains a leading cause of mortality in neonates. Mesenchymal stem cells derived from various tissues, such as bone marrow, umbilical cord, and adipose tissue, have beneficial effects on adult sepsis. Although human amniotic fluid stem cells (hAFSCs) have mesenchymal stem cell properties, the efficacy of hAFSCs on neonatal sepsis is yet to be elucidated. This study aimed to investigate the therapeutic potential of hAFSCs on neonatal sepsis using a rat model of lipopolysaccharide (LPS)-induced sepsis.

Methods

hAFSCs were isolated as CD117-positive cells from human amniotic fluid. Three-day-old rat pups were intraperitoneally treated with LPS to mimic neonatal sepsis. hAFSCs were administered either 3 h before or at 0, 3, or 24 h after LPS exposure. Serum inflammatory cytokine levels, gene expression profiles from spleens, and multiple organ damage were analyzed. hAFSC localization was determined in vivo. In vitro LPS stimulation tests were performed using neonatal rat peritoneal macrophages co-cultured with hAFSCs in a cell-cell contact-dependent/independent manner. Immunoregulation in the spleen was determined using a DNA microarray analysis.

Results

Prophylactic therapy with hAFSCs improved survival in the LPS-treated rats while the hAFSCs transplantation after LPS exposure did not elicit a therapeutic response. Therefore, hAFSC pretreatment was used for all subsequent studies. Inflammatory cytokine levels were elevated after LPS injection, which was attenuated by hAFSC pretreatment. Subsequently, inflammation-induced damages in the brain, lungs, and liver were ameliorated. hAFSCs aggregated with peritoneal macrophages and/or transiently accumulated in the liver, mesentery, and peritoneum. Paracrine factors released by hAFSCs induced M1-M2 macrophage polarization in a cell-cell contact-independent manner. Direct contact between hAFSCs and peritoneal macrophages further enhanced the polarization. Microarray analysis of the spleen showed that hAFSC pretreatment reduced the expression of genes involved in apoptosis and inflammation and subsequently suppressed toll-like receptor 4 signaling pathways.

Conclusions

Prophylactic therapy with hAFSCs improved survival in a rat model of LPS-induced neonatal sepsis. These effects might be mediated by a phenotypic switch from M1 to M2 in peritoneal macrophages, triggered by hAFSCs in a cell-cell contact-dependent/independent manner and the subsequent immunomodulation of the spleen.

Association of Histological and Clinical Chorioamnionitis With Neonatal Sepsis Among Preterm Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

Chorioamnionitis (CA) is considered a key risk factor for very preterm birth and for developing early onset sepsis (EOS) in preterm infants, but recent data suggest that CA might be protective against late onset sepsis (LOS). We performed a systematic review and meta-analysis of studies exploring the association between CA and sepsis. A comprehensive literature search was performed in PubMed/MEDLINE and EMBASE, from their inception to December 1, 2018. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Sources of heterogeneity were analyzed by subgroup and meta-regression analyses. The following categories of sepsis were analyzed: EOS, LOS, unspecified onset sepsis (UOS), culture-proven, and clinical sepsis. CA was subdivided into clinical and histological chorioamnionitis. Funisitis was also analyzed. We found 3,768 potentially relevant studies, of which 107 met the inclusion criteria (387,321 infants; 44,414 cases of CA). Meta-analysis showed an association between any CA and any EOS (OR 4.29, CI 3.63-5.06), any LOS (OR 1.29, CI 1.11-1.54), and any UOS (OR 1.59, CI 1.11-1.54). Subgroup analysis showed that CA was associated with culture-proven EOS (OR 4.69, CI 3.91-5.56), clinical EOS (OR 3.58, CI 1.90-6.76), and culture-proven LOS (OR 1.31, CI 1.12-1.53), but not with clinical LOS (OR 1.52, CI 0.78-2.96). The presence of funisitis did not increase the risk of either EOS or LOS when compared with CA without funisitis. CA-exposed infants had lower gestational age (-1.11 weeks, CI -1.37 to -0.84) than the infants not exposed to CA. Meta-regression analysis showed that the lower gestational age of the CA group correlated with the association between CA and LOS but not with the association between CA and EOS. In conclusion, our data suggest that the positive association between chorioamnionitis and LOS may be modulated by the effect of chorioamnionitis on gestational age.

The pattern of neonatal admissions and mortality at a regional and district hospital in the Upper West Region of Ghana; a cross sectional study

Background

High global neonatal deaths have triggered efforts to improve facility-based care. However, the outcomes achievable at different levels of care are unclear. This study compared morbidity and mortality patterns of newborns admitted to a regional and a district hospital in Ghana to determine outcome, risk and modifiable factors associated with mortality.

Objective

This study compared morbidity and mortality patterns of newborns admitted to a regional and a district hospital in Ghana to determine outcome, risk and modifiable factors associated with mortality

Methods

A cross-sectional study involving a records-review over one year at the Upper West Regional Hospital, and three years at St Joseph’s District Hospital, Jirapa was carried out. Age, sex, gestational age, weight, duration of admission, diagnosis, among others were examined. The data were analysed and statistical inference made.

Results

Altogether, 2004 newborns were examined, comprising 1,241(62%) from St Joseph’s District Hospital and 763(38%) from Upper West Regional Hospital. The proportion of neonatal deaths was similar, 8.94% (St Joseph’s District Hospital) and 8.91% (Upper West Regional Hospital). Prematurity, neonatal sepsis, birth asphyxia, low birth weight, neonatal jaundice and pneumonia contributed the most to mortality and suspected infections including malaria accounted for almost half (45.5%). Mortality was significantly associated with duration of stay of 48 hours, being premature, and being younger than 3 days.

Conclusion

Majority of the mortality among the neonates admitted was due to preventable causes. Better stabilization and further studies on the epidemiology of sepsis, prematurity, low birth weight, including the contribution of malaria to these and outcome of transferred neonates are needed.

Maternal activation of the EGFR prevents translocation of gut-residing pathogenic Escherichia coli in a model of late-onset neonatal sepsis

Late-onset sepsis (LOS) is a highly consequential complication of preterm birth and is defined by a positive blood culture obtained after 72 h of age. The causative bacteria can be found in patients' intestinal tracts days before dissemination, and cohort studies suggest reduced LOS risk in breastfed preterm infants through unknown mechanisms. Reduced concentrations of epidermal growth factor (EGF) of maternal origin within the intestinal tract of mice correlated to the translocation of a gut-resident human pathogen Escherichia coli, which spreads systemically and caused a rapid, fatal disease in pups. Translocation of Escherichia coli was associated with the formation of colonic goblet cell-associated antigen passages (GAPs), which translocate enteric bacteria across the intestinal epithelium. Thus, maternally derived EGF, and potentially other EGFR ligands, prevents dissemination of a gut-resident pathogen by inhibiting goblet cell-mediated bacterial translocation. Through manipulation of maternally derived EGF and alteration of the earliest gut defenses, we have developed an animal model of pathogen dissemination which recapitulates gut-origin neonatal LOS.

Vancomycin Is Protective in a Neonatal Mouse Model of Staphylococcus epidermidis-Potentiated Hypoxic-Ischemic Brain Injury

Infection is correlated with increased risk of neurodevelopmental sequelae in preterm infants. In modeling neonatal brain injury, Toll-like receptor agonists have often been used to mimic infections and induce inflammation. Using the most common cause of bacteremia in preterm infants, Staphylococcus epidermidis, we present a more clinically relevant neonatal mouse model that addresses the combined effects of bacterial infection together with subsequent hypoxic-ischemic brain insult. Currently, there is no neuroprotective treatment for the preterm population. Hence, we tested the neuroprotective effects of vancomycin with and without adjunct therapy using the anti-inflammatory agent pentoxifylline. We characterized the effects of S. epidermidis infection on the inflammatory response in the periphery and the brain, as well as the physiological changes in the central nervous system that might affect neurodevelopmental outcomes. Intraperitoneal injection of postnatal day 4 mice with a live clinical isolate of S. epidermidis led to bacteremia and induction of proinflammatory cytokines in the blood, as well as transient elevations of neutrophil and monocyte chemotactic cytokines and caspase 3 activity in the brain. When hypoxia-ischemia was induced postinfection, more severe brain damage was observed in infected animals than in saline-injected controls. This infection-induced inflammation and potentiated brain injury was inoculum dose dependent and was alleviated by the antibiotic vancomycin. Pentoxifylline did not provide any additional neuroprotective effect. Thus, we show for the first time that live S. epidermidis potentiates hypoxic-ischemic preterm brain injury and that peripheral inhibition of inflammation with antibiotics, such as vancomycin, reduces the extent of brain injury.

Effects of inflammation on the developing respiratory system: Focus on hypoglossal (XII) neuron morphology, brainstem neurochemistry, and control of breathing

Breathing is fundamental to life and any adverse change in respiratory function can endanger the health of an organism or even be fatal. Perinatal inflammation is known to adversely affect breathing in preterm babies, but lung infection/inflammation impacts all stages of life from birth to death. Little is known about the role of inflammation in respiratory control, neuronal morphology, or neural function during development. Animal models of inflammation can provide understanding and insight into respiratory development and how inflammatory processes alter developmental phenotype in addition to providing insight into new treatment modalities. In this review, we focus on recent work concerning the development of neurons, models of perinatal inflammation with an emphasis on two common LPS-based models, inflammation and its impact on development, and current and potential treatments for inflammation within the respiratory control circuitry of the mammalian brainstem. We have also discussed models of inflammation in adults and have specifically focused on hypoglossal motoneurons (XII) and neurons of the nucleus tractus solitarii (nTS) as these nuclei have been studied more extensively than other brainstem nuclei participating in breathing and airway control. Understanding the impact of inflammation on the developmental aspects of respiratory control and breathing pattern is critical to addressing problems of cardiorespiratory dysregulation in disease and this overview points out many gaps in our current knowledge.

Early-Onset Neonatal Sepsis

Despite the great progress made in neonatal and perinatal medicine over the last couple of decades, sepsis remains one of the main causes of morbidity and mortality. Sepsis in pediatric population was defined at the Pediatric Sepsis Consensus Conference in 2005. There is still no consensus on the definition of neonatal sepsis. Neonatal sepsis is a sepsis that occurs in the neonatal period. According to the time of occurrence, neonatal sepsis can be of early onset, when it occurs within the first 72 hours of birth and results from vertical transmission, and of late onset, in which the source of infection is found most often in the environment and occurs after the third day of life. The most common causes of early-onset sepsis are Group B Streptococcus (GBS) and E. coli. Risk factors can be mother-related and newborn-related. Clinical symptoms and signs of sepsis are quite unspecific. The dysfunction of different organs may imitate sepsis. On the other hand, infectious and non-infectious factors may exist simultaneously. The start of the antimicrobial therapy in any newborn with suspected sepsis should not be delayed. Pentoxifylline may have potential benefits in preterm newborns with sepsis. The only proven intervention that has been shown to reduce the risk of early-onset neonatal sepsis is intrapartum intravenous antibiotic administration to prevent GBS infection. It is still a great challenge to discontinue antibiotic treatment in non-infected newborns as soon as possible, because any extended antibiotic use may later be associated with other pathological conditions.

Acute Funisitis Correlates With the Risk of Early-Onset Sepsis in Term Newborns Assessed Using the Kaiser Sepsis Calculator

BACKGROUND

The risk of neonatal early-onset sepsis (EOS) is traditionally assessed on maternal signs of clinical chorioamnionitis. Recently, an online EOS risk calculator was developed by Kaiser Permanente using maternal and neonatal clinical parameters. We were interested in whether an increased Kaiser sepsis risk score correlates with histologic acute chorioamnionitis or acute funisitis.

DESIGN

Included in this retrospective review are 119 chorioamnionitis-exposed term neonates from January 1, 2015 and December 31, 2016. Clinical charts from mother-baby pairs were reviewed. An EOS risk score was obtained using the online Kaiser Sepsis Calculator. The presence and severity of acute chorioamnionitis and acute funisitis were recorded. A SPSS software was used for statistical analysis (IBM, New Jersey, USA).

RESULTS

The Kaiser Sepsis Calculator could identify 97 of 119 (81.5%) neonates without increased risk for sepsis. Histologic acute chorioamnionitis was present in 100 of 119 cases (84%), in which 44 cases (44%) show severe acute chorioamnionitis. Acute funisitis was recognized in 87 of 119 (73.1%) cases, all of which had concurrent acute chorioamnionitis. Severe funisitis was seen in 38 of the 87 cases (43.7%). The Kaiser Sepsis risk score correlates with the presence and severity of acute funisitis (P = .037 and P = .044, respectively) but not with the presence or the severity of acute chorioamnionitis (P = .105 and P = .672, respectively).

CONCLUSION

Our study provides histological evidence to support that the Kaiser Sepsis Calculator may help to effectively reduce unwarranted blood culture, antibiotics exposure, and neonatal intensive care unit admission in term neonates.

The Impact of Lactoferrin on the Growth of Intestinal Inhabitant Bacteria

Lactoferrin (Lf) is an iron-binding milk glycoprotein that promotes the growth of selected probiotic strains. The effect of Lf on the growth and diversification of intestinal microbiota may have an impact on several issues, including (i) strengthening the permeability of the epithelial cell monolayer, (ii) favoring the microbial antagonism that discourages the colonization and proliferation of enteric pathogens, (iii) enhancing the growth and maturation of cell-monolayer components and gut nerve fibers, and (iv) providing signals to balance the anti- and pro-inflammatory responses resulting in gut homeostasis. Given the beneficial role of probiotics, this contribution aims to review the current properties of bovine and human Lf and their derivatives in in vitro probiotic growth and Lf interplay with microbiota described in the piglet model. By using Lf as a component in pharmacological products, we may enable novel strategies that promote probiotic growth while conferring antimicrobial activity against multidrug-resistant microorganisms that cause life-threatening diseases, especially in neonates.

Practice variations and rates of late onset sepsis and necrotizing enterocolitis in very preterm born infants, a review

The burden of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) remains high for newborns in low- and high-income countries. Very preterm born infants born below 32 weeks gestation are at highest risk because their immune system is not yet adapted to ex-utero life, providing intensive care frequently compromises their skin or mucosa and they require a long duration of hospital stay. An epidemiological overview is difficult to provide because there is no mutually accepted definition available for either LOS or NEC. LOS incidence proportions are generally reported based on identified blood culture pathogens. However, discordance in minimum day of onset and whether coagulase negative staphylococci or fungi should be included into the reported proportions lead to variation in reported incidences. Complicating the comparison are the absence of biomarkers, ancillary lab tests or prediction models with sufficiently high positive and/or negative predictive values. The only high negative predictive values result from negative blood culture results with negative lab results allowing to discontinue antibiotic treatment. Similar difficulties exist in reporting and diagnosing NEC. Although most publications base their proportions on a modified version of Bell's stage 2 or 3, comparisons are made difficult by the multifactorial nature of the disease reflecting several pathways to intestinal necrosis, the absence of a reliable biomarker and the unclear differentiation from spontaneous intestinal perforations. Comparable reports in very low birthweight infants range between 5% and 30% for LOS and 1.6% to 7.1% for NEC. Evidence based guidelines to support treatment are missing. Treatment for LOS remains largely empirical and focused mainly on antibiotics. In the absence of a clear diagnosis, even unspecific early warning signals need to be met with antibiotic treatment. Cessation after negative blood culture is difficult unless the child was asymptomatic from the beginning. As a result, antibiotics are the most commonly prescribed medications, but unnecessary exposure may result in increased risk for mortality, NEC, further infections and childhood obesity or asthma. Finding ways to limit antibiotic use are thus important and have shown a large potential for improvement of care and limitation of cost. Over recent decades, none of the attempts to establish novel therapies have succeeded. LOS and NEC proportions remained mostly stable. During the past 10 years however, publications emerged reporting a reduction, sometimes by almost 50%. Most concern units participating in a surveillance system using quality improvement strategies to prevent LOS or NEC (e.g., hand hygiene, evidence based "bundles", feeding onset, providing own mother's milk). We conclude that these approaches display a potential for wider spread reduction of LOS and NEC and for a subsequently more successful development of novel therapies as these often address the same pathways as the prevention strategies.

Vascular Endothelium in Neonatal Sepsis: Basic Mechanisms and Translational Opportunities

Neonatal sepsis remains a major health issue worldwide, especially for low-birth weight and premature infants, with a high risk of death and devastating sequelae. Apart from antibiotics and supportive care, there is an unmet need for adjunctive treatments to improve the outcomes of neonatal sepsis. Strong and long-standing research on adult patients has shown that vascular endothelium is a key player in the pathophysiology of sepsis and sepsis-associated organ failure, through a direct interaction with pathogens, leukocytes, platelets, and the effect of soluble circulating mediators, in part produced by endothelial cells themselves. Despite abundant evidence that the neonatal immune response to sepsis is distinct from that of adults, comparable knowledge on neonatal vascular endothelium is much more limited. Neonatal endothelial cells express lower amounts of adhesion molecules compared to adult ones, and present a reduced capacity to neutralize reactive oxygen species. Conversely, available evidence on biomarkers of endothelial damage in neonates is not as robust as in adult patients, and endothelium-targeted therapeutic opportunities for neonatal sepsis are almost unexplored. Here, we summarize current knowledge on the structure of neonatal vascular endothelium, its interactions with neonatal immune system and possible endothelium-targeted diagnostic and therapeutic tools for neonatal sepsis. Furthermore, we outline areas of basic and translational research worthy of further study, to shed light on the role of vascular endothelium in the context of neonatal sepsis.

Cellular metabolism constrains innate immune responses in early human ontogeny

Pathogen immune responses are profoundly attenuated in fetuses and premature infants, yet the mechanisms underlying this developmental immaturity remain unclear. Here we show transcriptomic, metabolic and polysome profiling and find that monocytes isolated from infants born early in gestation display perturbations in PPAR-γ-regulated metabolic pathways, limited glycolytic capacity and reduced ribosomal activity. These metabolic changes are linked to a lack of translation of most cytokines and of MALT1 signalosome genes essential to respond to the neonatal pathogen Candida. In contrast, they have little impact on house-keeping phagocytosis functions. Transcriptome analyses further indicate a role for mTOR and its putative negative regulator DNA Damage Inducible Transcript 4-Like in regulating these metabolic constraints. Our results provide a molecular basis for the broad susceptibility to multiple pathogens in these infants, and suggest that the fetal immune system is metabolically programmed to avoid energetically costly, dispensable and potentially harmful immune responses during ontogeny.

Little is known about developmental set points of immune responses, especially in humans. Here the authors show that the metabolic state of monocytes isolated from prematurely born infants underlies attenuated responsiveness to fungal infection via selective control of protein translation.

Filling the Gaps: Current Research Directions for a Rational Use of Probiotics in Preterm Infants

The use of probiotics among very low-birth-weight infants is constantly increasing, as probiotics are believed to reduce the incidence of severe diseases such as necrotizing enterocolitis and late-onset sepsis and to improve feeding tolerance. However, despite the enthusiasm towards these products in neonatal medicine, theoretical knowledge and clinical applications still need to be improved. The purpose of this review is to give an overview of the most important gaps in the current literature about potential uses of probiotics in preterm infants, highlighting promising directions for future research. Specifically, further well-designed studies should aim at clarifying the impact of the type of feeding (mother's milk, donor milk, and formula) on the relationship between probiotic supplementation and clinical outcome. Moreover, future research is needed to provide solid evidence about the potential greater efficacy of multi-strain probiotics compared to single-strain products. Safety issues should also be addressed properly, by exploring the potential of paraprobiotics and risks connected to antibiotic resistance in preterm infants. Last, in light of increasing commercial and public interests, the long-term effect of routine consumption of probiotics in such a vulnerable population should be also evaluated.