Current and emerging treatments for neonatal sepsis

Association between maximum norepinephrine dosage and mortality risk in neonates with septic shock

The high-dose usage of norepinephrine is thought to cause high mortality in patients with septic shock. This study aims to explores the correlation between the maximum norepinephrine (NE) dosage (MND) and mortality in neonates with septic shock. This retrospective cohort study included neonates with evidence of septic shock and those who received NE infusion. The study included 123 neonates, with 106 in the survival group and 17 in the death group. The death group exhibited significantly lower birth weight (p = 0.022), 1-min Apgar score (p = 0.005), serum albumin (p < 0.001), and base excess (BE) (p = 0.001) levels, but higher lactate (LAC) levels (p = 0.009) compared to the survival group. MND demonstrated an ROC area under the curve of 0.775 (95% CI 0.63-0.92, p < 0.001) for predicting mortality, with an optimal threshold of 0.3 µg/(kg·min), a sensitivity of 82.4%, and a specificity of 75.5%. Multivariate logistic regression indicated that an MND > 0.3 µg/(kg·min) (OR, 12.08, 95% CI 2.28-64.01) was associated with a significantly higher mortality risk. Spearman rank correlation showed a positive correlation between MND and LAC (r = 0.252, p = 0.005), vasoactive-inotropic score (VIS) (r = 0.836, p < 0.001), and a negative correlation with BE (r = - 0.311, p = 0.001). MND > 0.3 µg/(kg min) is a useful predictive marker of mortality in neonatal septic shock.

Impacts of COVID-19 pandemic on culture-proven sepsis in neonates

Objective

To assess the effects of COVID-19 pandemic on the epidemiology of neonatal sepsis and the antibiotic resistance profiles of pathogens involved.

Methods

This retrospective cohort study analyzed infants diagnosed with culture-proven sepsis at the neonatal department of a tertiary children's hospital in East China from January 2016 to December 2022. We compared the clinical and microbiological characteristics of neonatal sepsis cases between the pre-pandemic Phase I (2016-2019) and during the COVID-19 pandemic Phase II (2020-2022).

Results

A total of 507 infants with 525 sepsis episodes were included, with 343 episodes in Phase I and 182 in Phase II. The incidence of early-onset sepsis (EOS) was significantly lower during Phase II (p < 0.05). Infants in Phase II had lower gestational ages and birth weights compared to Phase I. Clinical signs such as mottled skin, severe anemia, thrombocytopenia were more prevalent in Phase II, alongside a higher incidence of complications. Notably, necrotizing enterocolitis (NEC) (p < 0.05) and meningitis (p < 0.1) occurred more frequently during Phase II. Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) were the predominant pathogens isolated from infants of death and cases with complications. A significant decrease in the proportion of K. pneumoniae was observed in Phase II, alongside increased antibiotic resistance in both E. coli and K. pneumoniae. The period of the COVID-19 pandemic (Phase II) was identified as an independent risk factor for complications in infants with neonatal sepsis.

Conclusion

COVID-19 pandemic response measures correlated with a decrease in EOS and an increase in neonatal sepsis complications and antibiotic resistance.

Bifidobacterium: Host-Microbiome Interaction and Mechanism of Action in Preventing Common Gut-Microbiota-Associated Complications in Preterm Infants: A Narrative Review

The development and health of infants are intertwined with the protective and regulatory functions of different microorganisms in the gut known as the gut microbiota. Preterm infants born with an imbalanced gut microbiota are at substantial risk of several diseases including inflammatory intestinal diseases, necrotizing enterocolitis, late-onset sepsis, neurodevelopmental disorders, and allergies which can potentially persist throughout adulthood. In this review, we have evaluated the role of Bifidobacterium as commonly used probiotics in the development of gut microbiota and prevention of common diseases in preterm infants which is not fully understood yet. The application of Bifidobacterium as a therapeutical approach in the re-programming of the gut microbiota in preterm infants, the mechanisms of host-microbiome interaction, and the mechanism of action of this bacterium have also been investigated, aiming to provide new insights and opportunities in microbiome-targeted interventions in personalized medicine.

Clinical application value of serum neutrophil gelatinase-associated lipocalin in neonatal sepsis

BACKGROUND

To explore the value of serum neutrophil gelatinase-associated lipocalin (sNGAL) in the diagnosis and follow up of neonatal late-onset sepsis.

METHODS

A total of 69 infants were enrolled in this prospective study, including 49 infants of late-onset neonatal sepsis in the observation group, and 20 infants without infection serving as the control group. The sNGAL, C-reactive protein (CRP), and procalcitonin (PCT) concentrations were determined in both groups and compared at different time points. A receiver operating characteristic (ROC) curve was drawn to evaluate the values of the 3 parameters in the forecast of neonatal late-onset sepsis.

RESULTS

The levels of sNGAL, CRP, and PCT were all increased obviously (P<0.05) in the observation group on the first and second day following onset, compared to the control group. The sNGAL level was associated with the time of treatment. Surprisingly, the sNGAL level started to drop in the observation group with effective treatment on the 7th day following onset. A correlation was found between the concentration of sNGAL and inflammatory markers, such as CRP and PCT, on the first day. The area under the ROC curve (AUC) for sNGAL, CRP, and PCT was: 0.964, 0.925, and 0.94, respectively.

CONCLUSIONS

Increased sNGAL levels could reflect the inflammatory status in the acute stage of neonatal sepsis. When combined with other sepsis markers, such as CRP and PCT, the sNGAL is a useful marker in the rapid diagnosis and follow up of neonatal sepsis.

Pentaglobin (immunoglobulin M-enriched immunoglobulin) as adjuvant therapy for premature and very low-birth-weight neonates with sepsis

OBJECTIVES:

The purpose of this research was to determine the effectiveness of Pentaglobin® as adjuvant therapy in the treatment of sepsis in preterm newborns.

MATERIALS AND METHODS:

It was a prospective, observational, randomized study for 272 premature neonates and very low birth weight (VLBW) that were diagnosed with sepsis carried at neonatal intensive care units. The patients randomized into control group who received standard sepsis antibiotic treatments, and an intervention group who received Pentaglobin® 5 ml/kg daily for 3 consecutive days as an adjunct therapy to a standard sepsis antibiotic treatment.

RESULTS:

Multiple organisms that isolated from culture specimens were Gram-negative bacteria, Gram-positive, and candida (56.25%, 42.28%, and 1.47%, respectively). The disease duration was distinctively longer in patients who were treated by the standard antibiotic protocol (mean ± standard deviation [SD]: 30.76 ± 3.97, odds ratio [OR]: 30.76, 95% confidence interval [CI]: 30.051, 31.473) comparing to the patients who received Pentaglobin adjuvant therapy (mean ± SD: 26.48 ± 5.55, OR: 26.48, 95% CI: 25.489, 27.477) (P < 0.000). Patients treated by standard antibiotic protocol were associated to a substantially increased risk of death (11.76%, hazard ratio 4.400, 95% CI: 1.432, 13.529, P = 0.009).

CONCLUSION:

Neonatal sepsis is more common in premature and VLBW newborns, and Pentaglobin® management of newborn nosocomial sepsis might be used in addition to other therapies.

Early Gut Microbiota Colonisation of Premature Infants Fed with Breastmilk or Formula with or without Probiotics: A Cohort Study

Premature infants have a fragile ecology of the gut microbiota, which is associated with many health problems and may be influenced by formula versus breast feeding. The present study investigated differences in the process of gut microbiota colonisation in preterm infants fed with breastmilk or formula with or without probiotics before 12 weeks. This cohort study recruited 138 premature infants; 31 in the breastmilk (BM) group, 59 in the probiotics formula (PF) group and 48 in the non-probiotics formula (NPF) group, according to the feeding practice they received at birth. Gut bacterial composition was identified with 16S rRNA gene sequencing in faecal samples collected at 1 week, 6 weeks and 12 weeks after birth. The alpha diversity was higher in the PF group compared to the other groups at week 1 and 6 (both p < 0.01) but showed no difference at week 12. The beta diversity of the three groups showed a trend towards similarity at the first two stages (p < 0.001 and p = 0.009, respectively) and finally showed no difference at week 12. Canonical redundancy analysis showed that feeding type could explain the difference in gut microbiota composition at week one and six (both p < 0.01). At genus level, Bifidobacterium was enriched in the PF group, while the Enterococcus and Streptococcus was enriched in the NPF group. In summary, formula with probiotics feeding after birth can affect gut microbiota colonisation and lead to a bacterial community with less potential pathogens.

Leucine Reconstitutes Phagocytosis-Induced Cell Death in E. coli-Infected Neonatal Monocytes-Effects on Energy Metabolism and mTOR Signaling

MΦ differentiate from circulating monocytes (Mo). The reduced ability of neonatal Mo to undergo apoptosis after E. coli infection (phagocytosis-induced cell death (PICD)) could contribute to sustained inflammatory processes. The objective of our study was to investigate whether immune metabolism in Mo can be modified to gain access to pro-apoptotic signaling. To this end, we supplemented Mo from neonates and from adults with the branched amino acid leucine. In neonatal Mo, we observed increased energy production via oxidative phosphorylation (Oxphos) after E. coli infection via Seahorse assay. Leucine did not change phagocytic properties. In neonatal Mo, we detected temporal activation of the AKT and mTOR pathways, accompanied with subsequent activation of downstream targets S6 Kinase (S6K) and S6. FACS analyses showed that once mTOR activation was terminated, the level of anti-apoptotic BCL-2 family proteins (BCL-2; BCL-X_L) decreased. Release of cytochrome C and cleavage of caspase-3 indicated involvement of the intrinsic apoptotic pathway. Concomitantly, the PICD of neonatal Mo was initiated, as detected by hypodiploid DNA. This process was sensitive to rapamycin and metformin, suggesting a functional link between AKT, mTOR and the control of intrinsic apoptotic signaling. These features were unique to neonatal Mo and could not be observed in adult Mo. Supplementation with leucine therefore could be beneficial to reduce sustained inflammation in septic neonates.

Role of IgA in the early-life establishment of the gut microbiota and immunity: Implications for constructing a healthy start

Colonization and maturation of the gut microbiota (GM) during early life is a landmark event that fundamentally influences the (early) immunity and later-life health of various mammals. This is a delicate, systematic process that is biologically actively regulated by infants and their mothers, where (secretory) IgA, an important regulator of microbes found in breast milk and generated actively by infants, may play a key role. By binding to microbes, IgA can inhibit or enhance their colonization, influence their gene expression, and regulate immune responses. IgA dysfunction during early life is associated with disrupted GM maturation and various microbe-related diseases, such as necrotizing enterocolitis and diarrhea, which can also have a lasting effect on GM and host health. This review discusses the process of early GM maturation and its interaction with immunity and the role of IgA (focusing on milk secretory IgA) in regulating this process. The possible application of this knowledge in promoting normal GM maturation processes and immune education has also been highlighted.