Neonatal sepsis-induced cardiovascular dysfunction includes impaired myocardial function (which may be systolic and/or diastolic) and vasoregulatory failure (which may lead to vasodilation or vasoconstriction). The haemodynamic response in neonatal sepsis may therefore be hyperdynamic or hypodynamic, and the underlying pathophysiological mechanisms are heterogenous. The assessment of the neonate with sepsis and cardiovascular dysfunction is critical for targeted pathophysiology-based management. However, this assessment is challenging; it may include clinical features, echocardiography, electrocardiography and heart rate variability monitoring, non-invasive cardiac output monitoring (NICOM), near-infrared spectroscopy (NIRS) and biomarkers. Neonatologist performed echocardiography (NPE), in particular, can aid in the evaluation of the pathophysiological mechanism of cardiovascular dysfunction specific to each patient and further guide individualised management. IMPACT: WHAT DOES THIS ARTICLE ADD TO THE EXISTING LITERATURE?: This review provides an integrative overview of current methods for assessing cardiovascular dysfunction in neonatal sepsis, combining clinical evaluation with echocardiographic, electrocardiographic, non-invasive hemodynamic (NICOM, NIRS), and biomarker-based approaches to support early recognition and management.

The nitroimidazole antibiotic, metronidazole, is frequently prescribed to infants with serious intra-abdominal infections, and multiple dosing recommendations exist. We sought to evaluate the extent to which metronidazole doses and associated exposures achieved desired efficacy and safety in infants enrolled in the Antibiotic Safety in Infants with Complicated Intra-abdominal Infections (SCAMP) trial (NCT01994993). SCAMP participants received intravenous metronidazole as part of multimodal antimicrobial therapy. Participants received a 15 mg/kg loading dose and a 7.5 mg/kg maintenance dose at 24 h. A subsequent 7.5 mg/kg maintenance dose was administered every 12 h for participants of postmenstrual age (PMA) 23 to <34 weeks; 8 h for PMA 34-40 weeks; and 6 h for PMA >40 weeks. We evaluated associations between simulated metronidazole exposures and pre-specified surrogate pharmacodynamic targets and clinical outcomes of efficacy and safety. Nearly 100% of pharmacodynamic targets were met. Infants with therapeutic success (a composite efficacy outcome, defined as the absence of death, negative bacterial blood cultures, and presumptive clinical cure at 30 days) had higher Cmin,ss, Cmax,ss, AUC00-24,ss, and AUCcum compared with infants without therapeutic success. However, the relationships between these exposure measures and therapeutic success were not significant in logistic regression analysis adjusting for gestational age. Despite generally high simulated exposures, no relationships were observed between exposures and prespecified safety events (necrotizing enterocolitis, intestinal strictures, intestinal perforation, positive blood culture, seizures, death, and intraventricular hemorrhage). Findings support metronidazole dosing as administered in term and preterm infants in the SCAMP trial.

BACKGROUND:Early-life antibiotic exposure is disproportionately high compared to the burden of culture-proven early-onset sepsis (CP-EOS). We assessed the contribution of culture-negative cases to the overall antibiotic exposure in the first postnatal week. METHODS:We conducted a retrospective analysis across eleven countries in Europe, North America, and Australia. All late-preterm and term infants born between 2014 and 2018 who received intravenous antibiotics during the first postnatal week were classified as culture-negative cases treated for ≥5 days (CN ≥ 5d), culture-negative cases treated for <5 days (CN < 5d), or CP-EOS cases. RESULTS:Out of 757,979 infants, 21,703 (2.9%) received intravenous antibiotics. The number of infants classified as CN ≥ 5d, CN < 5d, and CP-EOS was 7996 (37%), 13,330 (61%), and 375 (1.7%). The incidence of CN ≥ 5d, CN < 5d, and CP-EOS was 10.6 (95% CI 10.3-10.8), 17.6 (95% CI 17.3-17.9), and 0.49 (95% CI 0.44-0.54) cases per 1000 livebirths. The median (IQR) number of antibiotic days administered for CN ≥ 5d, CN < 5d, and CP-EOS was 77 (77-78), 53 (52-53), and 5 (5-5) per 1000 livebirths. CONCLUSIONS:CN ≥ 5d substantially contributed to the overall antibiotic exposure, and was 21-fold more frequent than CP-EOS. Antimicrobial stewardship programs should focus on shortening antibiotic treatment for culture-negative cases. IMPACT:In a study of 757,979 infants born in high-income countries, we report a presumed culture-negative early-onset sepsis incidence of 10.6/1000 livebirths with an associated antibiotic exposure of 77 antibiotic days per 1000 livebirths. This study sheds light on the major contribution of presumed culture-negative early-onset sepsis to early-life antibiotic exposure. Given the diagnostic uncertainty surrounding culture-negative early-onset sepsis, the low mortality rate, and the disproportionate antibiotic exposure associated with this condition, our study emphasizes the importance of targeting culture-negative early-onset sepsis in antimicrobial stewardship programs.

Antibiotic exposure at the beginning of life can lead to increased antimicrobial resistance and perturbations of the developing microbiome. Early-life microbiome disruption increases the risks of developing chronic diseases later in life. Fear of missing evolving neonatal sepsis is the key driver for antibiotic overtreatment early in life. Bias (a systemic deviation towards overtreatment) and noise (a random scatter) affect the decision-making process. In this perspective, we advocate for a factual approach quantifying the burden of treatment in relation to the burden of disease balancing antimicrobial stewardship and effective sepsis management.

Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD.

Background The lack of a consensus definition of neonatal sepsis and a core outcome set (COS) proves a substantial impediment to research that influences policy and practice relevant to key stakeholders, patients and parents. Methods A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In the included studies, the described outcomes were extracted in accordance with the provisions of the Core Outcome Measures in Effectiveness Trials (COMET) handbook and registered. Results Among 884 abstracts identified, 90 randomised controlled trials (RCTs) were included in this review. Only 30 manuscripts explicitly stated the primary and/or secondary outcomes. A total of 88 distinct outcomes were recorded across all 90 studies included. These were then assigned to seven different domains in line with the taxonomy for classification proposed by the COMET initiative. The most frequently reported outcome was survival with 74% ( n = 67) of the studies reporting an outcome within this domain. Conclusions This systematic review constitutes one of the initial phases in the protocol for developing a COS in neonatal sepsis. The paucity of standardised outcome reporting in neonatal sepsis hinders comparison and synthesis of data. The final phase will involve a Delphi Survey to generate a COS in neonatal sepsis by consensus recommendation. Impact This systematic review identified a wide variation of outcomes reported among published RCTs on the management of neonatal sepsis. The paucity of standardised outcome reporting hinders comparison and synthesis of data and future meta-analyses with conclusive recommendations on the management of neonatal sepsis are unlikely. The final phase will involve a Delphi Survey to determine a COS by consensus recommendation with input from all relevant stakeholders.

Compared to term infants, the microbiota of preterm infants is less diverse and often enriched for potential pathogens (e.g., members of the family Enterobacteriaceae). Additionally, antibiotics are frequently given to preterm infants, further destabilizing the microbiota and increasing the risk of fungal infections. In a previous communication, our group showed that supplementation of the premature infant diet with medium-chain triglyceride (MCT) oil reduced the fungal burden of Candida spp. in the gastrointestinal tract. The objective of this study was to determine whether MCT supplementation impacts the bacterial component of the microbiome. Pre-term infants (n = 17) receiving enteral feedings of either infant formula (n = 12) or human milk (n = 5) were randomized to MCT supplementation (n = 9) or no supplementation (n = 8). Fecal samples were taken at randomization and prior to MCT supplementation (Week 0), on days 5–7 (Week 1) and day 21 (Week 3). After DNA extraction from samples, the QIIME2 pipeline was utilized to measure community diversity and composition (genera and phyla). Our findings show that MCT supplementation did not significantly alter microbiota diversity or composition in the gastrointestinal tract. Importantly, there were no significant changes in the family Enterobacteriaceae, suggesting that MCT supplementation did not enrich for potential pathogens. MCT holds promise as a therapeutic intervention for reducing fungal colonization without significant impact on the bacterial composition of the host gastrointestinal tract.

Antimicrobials are among the most frequently prescribed drugs in the neonatal intensive care unit (NICU), although most neonates exposed lack a bacterial infection. Overuse of antimicrobials carries risk to the patient and fosters the development of resistant organisms. Strategic and systematic processes hold promise to limit the unnecessary use of these drugs in this population. This study reports a quality improvement initiative in which 2 antimicrobial stewardship strategies were implemented in a large, regional NICU setting: an automatic stop order and an antimicrobial time-out. Antimicrobial use was compared before and after implementation. These 2 simple strategies were associated with a nearly 30% reduction in antibiotic use (31 days per 1000 patient days).

IMPORTANCE Appropriate use of antibiotics is life-saving in neonatal early-onset sepsis (EOS), but overuse of antibiotics is associated with antimicrobial resistance and long-term adverse outcomes. Large international studies quantifying early-life antibiotic exposure along with EOS incidence are needed to provide a basis for future interventions aimed at safely reducing neonatal antibiotic exposure. OBJECTIVE To compare early postnatal exposure to antibiotics, incidence of EOS, and mortality among different networks in high-income countries. DESIGN, SETTING, AND PARTICIPANTS This is a retrospective, cross-sectional study of late preterm and full-term neonates born between January 1, 2014, and December 31, 2018, in 13 hospital-based or population-based networks from 11 countries in Europe and North America and Australia. The study included all infants born alive at a gestational age greater than or equal to 34 weeks in the participating networks. Data were analyzed from October 2021 to March 2022. EXPOSURES Exposure to antibiotics started in the first postnatal week. MAIN OUTCOMES AND MEASURES The main outcomes were the proportion of late-preterm and full-term neonates receiving intravenous antibiotics, the duration of antibiotic treatment, the incidence of culture-proven EOS, and all-cause and EOS-associated mortality. RESULTS A total of 757 979 late-preterm and full-term neonates were born in the participating networks during the study period; 21703 neonates (2.86%; 95% CI, 2.83%-2.90%), including 12 886 boys (59.4%) with a median (IQR) gestational age of 39 (36-40) weeks and median (IQR) birth weight of 3250 (2750-3750) g, received i ntra venous antibiotics during the first postnatal week. The proportion of neonates started on antibiotics ranged from 1.18% to 12.45% among networks. The median (IQR) duration of treatment was 9 (7-14) days for neonates with EOS and 4(3-6)days for those without EOS. This led to an antibiotic exposure of 135 days per 1000 live births (range across networks, 54-491 days per 1000 live births). The incidence of EOS was 0.49 cases per 1000 live births (range, 0.18-1.45 cases per 1000 live births). EOS-associated mortality was 3.20% (12 of 375 neonates; range, 0.00%-12.00%). For each case of EOS, 58 neonates were started on antibiotics and 273 antibiotic days were administered. CONCLUSIONS AND RELEVANCE The findings of this study suggest that antibiotic exposure during the first postnatal week is disproportionate compared with the burden of EOS and that there are wide (up to 9-fold) variations internationally. This study defined a set of indicators reporting on both dimensions to facilitate benchmarking and future interventions aimed at safely reducing antibiotic exposure in early life.

Objective To evaluate the effect of a nutrition care bundle in improving growth in premature infants during neonatal hospitalization. Study design This study was a retrospective analysis of prospectively collected data for 584 surviving infants with birth weight <= 1000 g and gestational age 24-29 weeks admitted to a single-center neonatal intensive care unit between July 3, 2005, and June 6, 2016. Participants were divided into 3 discrete epochs based on evolving nutrition practices during the study period: epoch 1, baseline, open-bay setting; epoch 2, improved lactation staffing, introduction of high-protein formula, single-family roomsetting; epoch 3, complete nutrition care bundle. Infants in each epoch were evaluated for the primary outcome of change in weight z-score between postnatal day 7 and 36 weeks postmenstrual age (PMA) or discharge if sooner. Univariate and multivariable regression analyses were conducted to evaluate the effect of clinical variables on outcome. Results Significant increases in weight z-score between day of life 7 and 36 weeks PMA were observed across the 3 epochs, which accounted for 31% (P <.0001) of the variance. Variables that were positive predictors of weight z-score change included birth weight z-score, cesarean delivery, and later epochs of nutritional support. Variables that were negative predictors of weight change included gestational age, postnatal steroids, and days on parenteral nutrition. Conclusions Implementation of a nutrition care bundle was associated with improved weight gain in extremely low birth weight infants.

C. parapsilosis (Cp) is an emerging cause of bloodstream infections in certain populations. The Candida clade, including Cp, is increasingly developing resistance to the first and the second line of antifungals. Cp is frequently isolated from hands and skin surfaces, as well as the GI tract. Colonization by Candida predisposes individuals to invasive bloodstream infections. To successfully colonize or invade the host, yeast must be able to rapidly adhere to the body surfaces to prevent elimination by host defense mechanisms. Here we describe a method to measure adhesion of Cp to immobilized proteins under physiologic fluid shear, using an end-point adhesion assay in a commercially available multichannel microfluidic device. This method is optimized to improve reproducibility, minimize subjectivity, and allow for the fluorescent quantification of individual isolates. We also demonstrate that some clinical isolates of Cp show increased adhesion when grown in conditions mimicking a mammalian host, whereas a frequently used lab strain, CDC317, is non-adhesive under fluid shear.

Background: In premature infants, complicated intraabdominal infections (cIAIs) are a leading cause of morbidity and mortality. Although universally prescribed, the safety and effectiveness of commonly used antibiotic regimens have not been established in this population. Methods: Infants ≤33 weeks gestational age and <121 days postnatal age with cIAI were randomized to ≤10 days of ampicillin, gentamicin, and metronidazole (group 1); ampicillin, gentamicin, and clindamycin (group 2); or piperacillin-tazobactam and gentamicin (group 3) at doses stratified by postmenstrual age. Due to slow enrollment, a protocol amendment allowed eligible infants already receiving study regimens to enroll without randomization. The primary outcome was mortality within 30 days of study drug completion. Secondary outcomes included adverse events, outcomes of special interest, and therapeutic success (absence of death, negative cultures, and clinical cure score >4) 30 days after study drug completion. Results: One hundred eighty infants [128 randomized (R), 52 nonrandomized (NR)] were enrolled: 63 in group 1 (45 R, 18 NR), 47 in group 2 (41 R, 6 NR), and 70 in group 3 (42 R, 28 NR). Thirty-day mortality was 8%, 7%, and 9% in groups 1, 2, and 3, respectively. There were no differences in safety outcomes between antibiotic regimens. After adjusting for treatment group and gestational age, mortality rates through end of follow-up were 4.22 [95% confidence interval (CI): 1.39–12.13], 4.53 (95% CI: 1.21–15.50), and 4.07 (95% CI: 1.22–12.70) for groups 1, 2, and 3, respectively. Conclusions: Each of the antibiotic regimens are safe in premature infants with cIAI. Clinical Trial Registration: NCT0199499

Invasive Candida infections are frequent complications of the immunocompromised and are associated with substantive morbidity and mortality. Although C. albicans is the best-studied species, emerging infections by non- albicans Candida species have led to increased efforts to understand aspects of their pathogenesis that are unique from C. albicans . C. parapsilosis is a frequent cause of invasive infections, particularly among premature infants.

Pathogenic fungi represent a small subset of a markedly diverse kingdom of organisms [...]

INTRODUCTION:Recent reports suggest SARS-CoV-2, the virus causing COVID-19, may be transmittable from pregnant mother to placenta and fetus, albeit rarely. The efficacy of vertical transmission of SARS-CoV-2 critically depends on the availability of its receptor, ACE2, in the placenta. In the present study, we tested the hypothesis that placental ACE2 expression is oxygenation-dependent by studying the expression of ACE2 and associated cell entry regulators in the monochorionic twin anemia-polycythemia (TAPS) placenta, a model of discordant placental oxygenation. METHODS:We performed a retrospective comparative immunohistochemical, immunofluorescence and Western blot analysis of ACE2, TMPRSS2 and Cathepsin B expression in anemic and polycythemic territories of TAPS placentas (N = 14). RESULTS:ACE2 protein levels were significantly higher in the anemic twin territories than in the corresponding polycythemic territories, associated with upregulation of the key ACE2-related cell entry regulators, TMPRSS2 and Cathepsin B, immunolocalized to villous trophoblastic and stromal cells. Cellular colocalization of ACE2 and TMPRSS2, suggestive of functionality of this cell entry axis, was demonstrated by double immunofluorescence studies. DISCUSSION:Placental hypoxia is associated with upregulation of ACE2 expression, concomitant with increased expression of its key cell entry proteases. ACE2-regulated placental functions, both infection- and non-infection related, may be highly oxygenation-dependent.

Introduction Neonatal sepsis is a leading cause of infant mortality worldwide with non-specific and varied presentation. We aimed to catalogue the current definitions of neonatal sepsis in published randomised controlled trials (RCTs). Method A systematic search of the Embase and Cochrane databases was performed for RCTs which explicitly stated a definition for neonatal sepsis. Definitions were sub-divided into five primary criteria for infection (culture, laboratory findings, clinical signs, radiological evidence and risk factors) and stratified by qualifiers (early/late-onset and likelihood of sepsis). Results Of 668 papers screened, 80 RCTs were included and 128 individual definitions identified. The single most common definition was neonatal sepsis defined by blood culture alone (n = 35), followed by culture and clinical signs (n = 29), and then laboratory tests/clinical signs (n = 25). Blood culture featured in 83 definitions, laboratory testing featured in 48 definitions while clinical signs and radiology featured in 80 and 8 definitions, respectively. Discussion A diverse range of definitions of neonatal sepsis are used and based on microbiological culture, laboratory tests and clinical signs in contrast to adult and paediatric sepsis which use organ dysfunction. An international consensus-based definition of neonatal sepsis could allow meta-analysis and translate results to improve outcomes.

Sepsis remains a leading cause of morbidity and mortality in the neonatal population, and at present, there is no unified definition of neonatal sepsis. Existing consensus sepsis definitions within paediatrics are not suited for use in the NICU and do not address sepsis in the premature population. Many neonatal research and surveillance networks have criteria for the definition of sepsis within their publications though these vary greatly and there is typically a heavy emphasis on microbiological culture. The concept of organ dysfunction as a diagnostic criterion for sepsis is rarely considered in neonatal literature, and it remains unclear how to most accurately screen neonates for organ dysfunction. Accurately defining and screening for sepsis is important for clinical management, health service design and future research. The progress made by the Sepsis-3 group provides a roadmap of how definitions and screening criteria may be developed. Similar initiatives in neonatology are likely to be more challenging and would need to account for the unique presentation of sepsis in term and premature neonates. The outputs of similar consensus work within neonatology should be twofold: a validated definition of neonatal sepsis and screening criteria to identify at-risk patients earlier in their clinical course. Impact There is currently no consensus definition of neonatal sepsis and the definitions that are currently in use are varied. A consensus definition of neonatal sepsis would benefit clinicians, patients and researchers. Recent progress in adults with publication of Sepsis-3 provides guidance on how a consensus definition and screening criteria for sepsis could be produced in neonatology. We discuss common themes and potential shortcomings in sepsis definitions within neonatology. We highlight the need for a consensus definition of neonatal sepsis and the challenges that this task poses.