Less is more: Antibiotics at the beginning of life

Effect of β-lactam antibiotics on the gut microbiota of term neonates

β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns' gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery.

Neonatal bacterial sepsis

Neonatal sepsis remains one of the key challenges of neonatal medicine, and together with preterm birth, causes almost 50% of all deaths globally for children younger than 5 years. Compared with advances achieved for other serious neonatal and early childhood conditions globally, progress in reducing neonatal sepsis has been much slower, especially in low-resource settings that have the highest burden of neonatal sepsis morbidity and mortality. By contrast to sepsis in older patients, there is no universally accepted neonatal sepsis definition. This poses substantial challenges in clinical practice, research, and health-care management, and has direct practical implications, such as diagnostic inconsistency, heterogeneous data collection and surveillance, and inappropriate treatment, health-resource allocation, and education. As the clinical manifestation of neonatal sepsis is frequently non-specific and the current diagnostic standard blood culture has performance limitations, new improved diagnostic techniques are required to guide appropriate and warranted antimicrobial treatment. Although antimicrobial therapy and supportive care continue as principal components of neonatal sepsis therapy, refining basic neonatal care to prevent sepsis through education and quality improvement initiatives remains paramount.

An Infant With COVID-19 Presenting With a Bulging Fontanel: A Case Report and Literature Review

A bulging fontanel is a sign of elevated intracranial pressure, which can be caused by diseases with intracranial fluid retention or swelling of the cerebral parenchyma. We experienced a case of an infant with a typical course of mild coronavirus disease 2019 (COVID-19) but with a bulging fontanel as a finding at presentation. The patient, a three-month-old boy with no underlying conditions, presented to the emergency clinic with fever, vomiting, and loss of appetite. Due to the absence of crying and the bulging fontanel, he was referred to our hospital with suspected bacterial meningitis. The diameter of the anterior fontanel was 2.5 cm, as measured by the Popich and Smith method. He showed no signs of consciousness impairment and appeared to be as active as usual. Computed tomography revealed a bulging fontanel. Cerebrospinal fluid examination showed no elevated cell counts, and cultures were negative. Accordingly, bacterial meningitis was ruled out. The fever resolved on the day after admission, and the patient was discharged on the third day after admission in good general condition. When an infant diagnosed with COVID-19 presents with a bulging fontanel, it is important to be aware of its low specificity and excessive antibiotic treatment should be reconsidered.

Porous silicon-based sensing and delivery platforms for wound management applications

Wound management remains a great challenge for clinicians due to the complex physiological process of wound healing. Porous silicon (PSi) with controlled pore morphology, abundant surface chemistry, unique photonic properties, good biocompatibility, easy biodegradation and potential bioactivity represent an exciting class of materials for various biomedical applications. In this review, we focus on the recent progress of PSi in the design of advanced sensing and delivery systems for wound management applications. Firstly, we comprehensively introduce the common type, normal healing process, delaying factors and therapeutic drugs of wound healing. Subsequently, the typical fabrication, functionalization and key characteristics of PSi have been summarized because they provide the basis for further use as biosensing and delivery materials in wound management. Depending on these properties, the rise of PSi materials is evidenced by the examples in literature in recent years, which has emphasized the robust potential of PSi for wound monitoring, treatment and theranostics. Finally, challenges and opportunities for the future development of PSi-based sensors and delivery systems for wound management applications are proposed and summarized. We hope that this review will help readers to better understand current achievements and future prospects on PSi-based sensing and delivery systems for advanced wound management.

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

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

The microbiome in pregnancy and early life-Highlights from the 11th Maria Delivoria-Papadopoulos Perinatal Symposium

This review was based on a symposium that examined novel aspects of the microbiome during pregnancy and early life and explored papers published by the lecturers. For example, it showed that bacterial extracellular vesicles derived from the microbiome harboured in various maternal niches, carried bacterial deoxyribonucleic acid, were isolated from the placenta and may have confounded placental microbiome studies. Maternal diet was responsible for the composition and diversity of breast milk microbiota, and may have shaped the offspring's microbiome and influenced their immune components. Probiotics and antibiotics administered perinatally may have had beneficial but also long-lasting adverse effects on offspring.

Incidence of Antibiotic Exposure for Suspected and Proven Neonatal Early-Onset Sepsis between 2019 and 2021: A Retrospective, Multicentre Study

Management of suspected early-onset sepsis (EOS) is undergoing continuous evolution aiming to limit antibiotic overtreatment, yet current data on the level of overtreatment are only available for a select number of countries. This study aimed to determine antibiotic initiation and continuation rates for suspected EOS, along with the incidence of culture-proven EOS in The Netherlands. In this retrospective study from 2019 to 2021, data were collected from 15 Dutch hospitals, comprising 13 regional hospitals equipped with Level I-II facilities and 2 academic hospitals equipped with Level IV facilities. Data included birth rates, number of neonates started on antibiotics for suspected EOS, number of neonates that continued treatment beyond 48 h and number of neonates with culture-proven EOS. Additionally, blood culture results were documented. Data were analysed both collectively and separately for regional and academic hospitals. A total of 103,492 live-born neonates were included. In 4755 neonates (4.6%, 95% CI 4.5-4.7), antibiotic therapy was started for suspected EOS, and in 2399 neonates (2.3%, 95% CI 2.2-2.4), antibiotic treatment was continued beyond 48 h. Incidence of culture-proven EOS was 1.1 cases per 1000 live births (0.11%, 95% CI 0.09-0.14). Overall, for each culture-proven EOS case, 40.6 neonates were started on antibiotics and in 21.7 neonates therapy was continued. Large variations in treatment rates were observed across all hospitals, with the number of neonates initiated and continued on antibiotics per culture-proven EOS case varying from 4 to 90 and from 4 to 56, respectively. The high number of antibiotic prescriptions compared to the EOS incidence and wide variety in clinical practice among hospitals in The Netherlands underscore both the need and potential for a novel approach to the management of neonates with suspected EOS.

Baicalin restore intestinal damage after early-life antibiotic therapy: the role of the MAPK signaling pathway

Antibiotic related intestinal injury in early life affects subsequent health and susceptibility. Here, we employed weaned piglets as a model to investigate the protective effects of baicalin against early-life antibiotic exposure-induced microbial dysbiosis. Piglets exposed to lincomycin showed a marked reduction in body weight (p < 0.05) and deterioration of jejunum intestinal morphology, alongside an increase in antibiotic-resistant bacteria such as Staphylococcus, Dolosicoccus, Escherichia-Shigella, and Raoultella. In contrast, baicalin treatment resulted in body weights, intestinal morphology, and microbial profiles that closely resembled those of the control group (p > 0.05), with a significant increase in norank_f_Muribaculaceae and Prevotellaceae_NK3B31_group colonization compared with lincomycin group (p < 0.05). Further analysis through fecal microbial transplantation into mice revealed that lincomycin exposure led to significant alterations in intestinal morphology and microbial composition, notably increasing harmful microbes and decreasing beneficial ones such as norank_Muribaculaceae and Akkermansia (p < 0.05). This shift was associated with an increase in harmful metabolites and disruption of the calcium signaling pathway gene expression. Conversely, baicalin supplementation not only counteracted these effects but also enhanced beneficial metabolites and regulated genes within the MAPK signaling pathway (MAP3K11, MAP4K2, MAPK7, MAPK13) and calcium channel proteins (ORA13, CACNA1S, CACNA1F and CACNG8), suggesting a mechanism through which baicalin mitigates antibiotic-induced intestinal and microbial disturbances. These findings highlight baicalin's potential as a plant extract-based intervention for preventing antibiotic-related intestinal injury and offer new targets for therapeutic strategies.

Use of the "Sepsis Risk Calculator" in Belgian Newborns: A Retrospective Cohort Study

BACKGROUND

Prevention of early-onset neonatal sepsis (EONS) is a frequent reason why many newborns receive unnecessary antibiotics. The Sepsis Risk Calculator (SRC) was developed by the Kaiser Permanente Institute as a multivariate risk assessment of EONS, aiming to reduce laboratory testing and empiric neonatal antibiotic therapy. Our objective was to assess the potential of the SRC in reducing antibiotic use in our setting.

METHODS

Late preterm and term newborns who received antibiotics from 2019 to 2020 in a tertiary Belgian hospital were included. Newborn-specific data were collected and entered into the online SRC, retrospectively calculating a sepsis risk score and providing recommendations for antibiotic administration. False-positive indications for treatment by the SRC were estimated based on previously published data. Antibiotic therapy rates according to the SRC recommendations were compared to the actual rate of antibiotic therapy.

RESULTS

Of 5891 births, 414 newborns received antibiotics and were eligible for this study, representing a rate of 7.6% of newborns receiving antibiotics following our current guidelines. The SRC would have recommended antibiotic administration for 2.7%, reducing antibiotic therapy by 64.5%. Of 5 possible cases of EONS, 3 would have received antibiotics in the first 24 hours according to the SRC.

CONCLUSIONS

In this Belgian cohort, use of the SRC has the potential to significantly decrease by 64.5% the newborns that receive antibiotics. This reduction would primarily concern asymptomatic newborns. If use of the SRC was to be implemented in Belgian maternities, strict clinical surveillance practices should be ensured.

A decade of neonatal sepsis in Stockholm, Sweden: Gram-positive pathogens were four times as common as Gram-negatives

PURPOSE

To assess Gram-positive bacterial (GPB) bloodstream infection (BSI) in neonates, covering incidence, morbidity, mortality, antimicrobial resistance patterns and biomarkers in Region Stockholm, Sweden between 2006 and 2016.

METHODS

A population-based retrospective epidemiological study including infants with GPB-BSI, admitted to the neonatal units at Karolinska University Hospital (KUH). Data were collected from patient records, the Swedish Neonatal Quality Register, the microbiological laboratory at KUH and the Swedish Public Health Agency.

RESULTS

We identified 357 infants with GPB-BSI, representing an incidence of 1.47/1000 live births (LB). Group B streptococcus (GBS) was the most common pathogen causing BSI in full-term infants and early-onset sepsis (EOS) (0.20/1000 LB), while coagulase-negative staphylococci (CoNS) were predominant in infants born very preterm and in late-onset sepsis (LOS) (0.79/1000 LB). There were no fatal GBS BSI cases, but 10.2% developed meningitis. The GPB case fatality rate was 9.5% and the sepsis fatality rate 2.8%. In GPB-BSI, 1/10 did not have an elevated C-reactive protein level. Staphylococcus aureus (S. aureus) BSI increased during the study period, but no methicillin or vancomycin resistant strains were found. The antimicrobial resistance (AMR) rate was highest in CoNS isolates.

CONCLUSION

GPB-BSI was four times more common than Gram-negative BSI in neonates but resulted in lower mortality rate. GBS was the most common pathogen in full-term infants and in EOS. CoNS was the most common pathogen in LOS and infants born very preterm, and the AMR rate was high in these isolates. The increasing trend of S. aureus BSI indicates a need of further investigation.

Metal natural product complex Ru-procyanidins with quadruple enzymatic activity combat infections from drug-resistant bacteria

Bacterial infection hampers wound repair by impeding the healing process. Concurrently, inflammation at the wound site triggers the production of reactive oxygen species (ROS), causing oxidative stress and damage to proteins and cells. This can lead to chronic wounds, posing severe risks. Therefore, eliminating bacterial infection and reducing ROS levels are crucial for effective wound healing. Nanozymes, possessing enzyme-like catalytic activity, can convert endogenous substances into highly toxic substances, such as ROS, to combat bacteria and biofilms without inducing drug resistance. However, the current nanozyme model with single enzyme activity falls short of meeting the complex requirements of antimicrobial therapy. Thus, developing nanozymes with multiple enzymatic activities is essential. Herein, we engineered a novel metalloenzyme called Ru-procyanidin nanoparticles (Ru-PC NPs) with diverse enzymatic activities to aid wound healing and combat bacterial infections. Under acidic conditions, due to their glutathione (GSH) depletion and peroxidase (POD)-like activity, Ru-PC NPs combined with H2O2 exhibit excellent antibacterial effects. However, in a neutral environment, the Ru-PC NPs, with catalase (CAT) activity, decompose H2O2 to O2, alleviating hypoxia and ensuring a sufficient oxygen supply. Furthermore, Ru-PC NPs possess exceptional antioxidant capacity through their superior superoxide dismutase (SOD) enzyme activity, effectively scavenging excess ROS and reactive nitrogen species (RNS) in a neutral environment. This maintains the balance of the antioxidant system and prevents inflammation. Ru-PC NPs also promote the polarization of macrophages from M1 to M2, facilitating wound healing. More importantly, Ru-PC NPs show good biosafety with negligible toxicity. In vivo wound infection models have confirmed the efficacy of Ru-PC NPs in inhibiting bacterial infection and promoting wound healing. The focus of this work highlights the quadruple enzymatic activity of Ru-PC NPs and its potential to reduce inflammation and promote bacteria-infected wound healing.

Antibiotic use in infants at risk of early-onset sepsis: results from a unicentric retrospective cohort study

BACKGROUND

Antibiotic use for early-onset sepsis represents a high percentage of antibiotic consumption in the neonatal setting. Measures to assess infants at risk of early-onset sepsis are needed to optimize antibiotic use. Our primary objective was to assess the impact of a departmental guideline on antibiotic use among term infants with suspected EOS not confirmed, in our neonatal unit.

METHODS

Retrospective cohort study, to compare antibiotic use in term infants during a baseline period of January to December 2018, and a postintervention period from October 2019, to September 2020, respectively. The primary outcome was antibiotic use measured by days of therapy, the antibiotic spectrum index, the antibiotic use rate, and the length of therapy.

RESULTS

We included 71 infants in the baseline period and 66 infants in the postintervention period. Compared to those in the baseline period, there was a significant reduction in overall antibiotic measures in the postintervention period, (P < 0.001). The total days of therapy/1000 patient-days decreased from 63/1000 patient-days during the baseline period to 25.8/1000 patient-days in the postintervention period, representing a relative reduction of 59%. The antibiotic use rate decreased by more than half of the infants, from 3.2% during the baseline period to 1.3% in the postintervention period.

CONCLUSIONS

The use of a departmental guideline to assess infants at risk of early-onset sepsis based on their clinical condition and prompt discontinuation of antibiotics, is a simple and low-cost measure that contributed to an important decrease in antibiotic use.

Antibiotic Use in a Neonatal Intensive Care Unit Practicing Integrative Medicine-A Retrospective Analysis

Background: Antibiotic use in neonatal intensive care units (NICUs) remains high. Low antibiotic prescribing has been documented among physicians trained in complementary medicine. This study sought to identify if an NICU integrating complementary medicine has low antibiotic prescribing. Methods: We conducted a retrospective analysis at the level-2 NICU of the Filderklinik, an integrative medicine hospital in Southern Germany, to compare antibiotic use locally and internationally; to compare neonates with suspected infection, managed with and without antibiotics; and to describe use and safety of complementary medicinal products. Results: Among 7778 live births, 1086 neonates were hospitalized between 2014 and 2017. Two hundred forty-six were diagnosed with suspected or confirmed infection, their median gestational age was 40.3 weeks (range 29-42), 3.25% had a birthweight <2500 g, 176 were treated with antibiotics for a median duration of 4 days, 6 had culture-proven infection (0.77 per 1000 live births), and 2.26% of live births were started on antibiotics. A total of 866 antibiotic treatment days corresponded to 111 antibiotic days per 1000 live births and 8.8 antibiotic days per 100 hospital days. Neonates managed with antibiotics more often had fever and abnormal laboratory parameters than those managed without. Complementary medicinal products comprising 71 different natural substances were used, no side effect or adverse event were described. A subanalysis using the inclusion criteria of a recent analysis of 13 networks in Europe, North America, and Australia confirmed this cohort to be among the lowest prescribing networks. Conclusions: Antibiotic use was low in this NICU in both local and international comparison, while the disease burden was in the mid-range, confirming an association between integrative medicine practice and low antibiotic prescribing in newborns. Complementary medicinal products were widely used and well tolerated. Clinical Trial Registration number: NCT04893343.

Synergistic inhibition mechanism of quinazolinone and piperacillin on penicillin-binding protein 2a: a promising approach for combating methicillin-resistant Staphylococcus aureus

The production of penicillin-binding protein 2a (PBP2a), a cell wall synthesis protein, is primarily responsible for the high-level resistance observed in methicillin-resistant Staphylococcus aureus (MRSA). PBP2a exhibits a significantly reduced affinity for most β-lactam antibiotics owing to its tightly closed active site. Quinazolinones (QNE), a novel class of non-β-lactam antibiotics, could initiate the allosteric regulation of PBP2a, resulting in the opening of the initially closed active pocket. Based on our previous study, we have a basic understanding of the dual-site inhibitor ceftaroline (CFT) induced allosteric regulation of PBP2a. However, there are still limitations in the knowledge of how combining medicines, QNE and piperacillin (PIP), induce the allosteric response of PBP2a and inhibit its function. Herein, molecular dynamics (MD) simulations were performed to elucidate the intricate mechanisms underlying the combination mode of QNE and PIP. Our study successfully captured the opening process of the active pocket upon the binding of the QNE at the allosteric site, which alters the signaling pathways with a favorable transmission to the active site. Subsequent docking experiments with different conformational states of the active pocket indicated that all three inhibitors, PIP, QNE, and CFT, exhibited higher docking scores and more favorable docking poses to the open active pocket. These findings reveal the implied mechanism of QNE-mediated allostery underlying combination therapy and provide novel insights into developing innovative therapeutic modalities against MRSA.Communicated by Ramaswamy H. Sarma.

An Overview of Antibiotic Therapy for Early- and Late-Onset Neonatal Sepsis: Current Strategies and Future Prospects

Neonatal sepsis is a clinical syndrome mainly associated with a bacterial infection leading to severe clinical manifestations that could be associated with fatal sequalae. According to the time of onset, neonatal sepsis is categorized as early- (EOS) or late-onset sepsis (LOS). Despite blood culture being the gold standard for diagnosis, it has several limitations, and early diagnosis is not immediate. Consequently, most infants who start empirical antimicrobial therapy do not have an underlying infection. Despite stewardship programs partially reduced this negative trend, in neonatology, antibiotic overuse still persists, and it is associated with several relevant problems, the first of which is the increase in antimicrobial resistance (AMR). Starting with these considerations, we performed a narrative review to summarize the main findings and the future prospects regarding antibiotics use to treat neonatal sepsis. Because of the impact on morbidity and mortality that EOS and LOS entail, it is essential to start an effective and prompt treatment as soon as possible. The use of targeted antibiotics is peremptory as soon as the pathogen in the culture is detected. Although prompt therapy is essential, it should be better assessed whether, when and how to treat neonates with antibiotics, even those at higher risk. Considering that we are certainly in the worrying era defined as the "post-antibiotic era", it is still essential and urgent to define novel strategies for the development of antibacterial compounds with new targets or mechanisms of action. A future strategy could also be to perform well-designed studies to develop innovative algorithms for improving the etiological diagnosis of infection, allowing for more personalized use of the antibiotics to treat EOS and LOS.

Antibiotic Use in Late Preterm and Full-Term Newborns

Importance

Antibiotic treatment saves lives in newborns with early-onset sepsis (EOS), but unwarranted antibiotic use is associated with resistant bacteria and adverse outcomes later in life. Surveillance is needed to optimize treatment strategies.

Objective

To describe antibiotic use in association with the incidence and mortality from EOS among late-preterm and full-term newborns.

Design, Setting, and Participants

The Sweden Neonatal Antibiotic Use study was a nationwide observational study that included all late-preterm and full-term neonates born from January 1, 2012, to December 31, 2020, in neonatal units of all levels. All hospital live births from 34 weeks' gestation during the study period were included in the study. Data were collected from the Swedish Neonatal Quality Register and the Swedish Medical Birth Register. Data were analyzed from August 2022 to May 2023.

Exposure

Admission for neonatal intensive care during the first week of life.

Main Outcomes and Measures

The main outcomes were the usage of intravenous antibiotics during the first week of life, the duration of antibiotic therapy, the rate of culture-proven EOS, and mortality associated with EOS.

Results

A total of 1 025 515 newborns were included in the study; 19 286 neonates (1.88%; 7686 girls [39.9%]; median [IQR] gestational age, 40 [38-41] weeks; median [IQR] birth weight, 3610 [3140-4030] g) received antibiotics during the first week of life, of whom 647 (3.4%) had EOS. The median (IQR) duration of antibiotic treatment in newborns without EOS was 5 (3-7) days, and there were 113 antibiotic-days per 1000 live births. During the study period there was no significant change in the exposure to neonatal antibiotics or antibiotic-days per 1000 live births. The incidence of EOS was 0.63 per 1000 live births, with a significant decrease from 0.74 in 2012 to 0.34 in 2020. Mortality associated with EOS was 1.39% (9 of 647 newborns) and did not change significantly over time. For each newborn with EOS, antibiotic treatment was initiated in 29 newborns and 173 antibiotic-days were dispensed.

Conclusions and Relevance

This large nationwide study found that a relatively low exposure to antibiotics is not associated with an increased risk of EOS or associated mortality. Still, future efforts to reduce unwarranted neonatal antibiotic use are needed.

Variation in antibiotic consumption in very preterm infants-a 10 year population-based study

OBJECTIVES

Wide variations in antibiotic use in very preterm infants have been reported across centres despite similar rates of infection. We describe 10 year trends in use of antibiotics and regional variations among very preterm infants in Norway.

PATIENTS AND METHODS

All live-born very preterm infants (<32 weeks gestation) admitted to any neonatal unit in Norway during 2009-18 were included. Main outcomes were antibiotic consumption expressed as days of antibiotic therapy (DOT) per 1000 patient days (PD), regional variations in use across four health regions, rates of sepsis and sepsis-attributable mortality and trends of antibiotic use during the study period.

RESULTS

We included 5296 infants: 3646 (69%) were born at 28-31 weeks and 1650 (31%) were born before 28 weeks gestation with similar background characteristics across the four health regions. Overall, 80% of the very preterm infants received antibiotic therapy. The most commonly prescribed antibiotics were the combination of narrow-spectrum β-lactams and aminoglycosides, but between 2009 and 2018 we observed a marked reduction in their use from 100 to 40 DOT per 1000 PD (P < 0.001). In contrast, consumption of broad-spectrum β-lactams remained unchanged (P = 0.308). There were large variations in consumption of vancomycin, broad-spectrum β-lactams and first-generation cephalosporins, but no differences in sepsis-attributable mortality across regions.

CONCLUSIONS

The overall antibiotic consumption was reduced during the study period. Marked regional variations remained in consumption of broad-spectrum β-lactams and vancomycin, without association to sepsis-attributable mortality. Our results highlight the need for antibiotic stewardship strategies to reduce consumption of antibiotics that may enhance antibiotic resistance development.

Standardization of urinary tract infection diagnosis in the neonatal ICU: Experience at a tertiary care center

BACKGROUND

Urinary tract infections (UTIs) and antibiotic overexposure are common neonatal problems. Recently, evidence has emerged that a standardized approach to neonatal UTI can reduce unnecessary diagnosis without complications. This quality improvement project aimed to achieve those goals in our neonatal intensive care unit (NICU).

METHODS

A UTI diagnosis guideline was adapted from the literature with the goal of maximizing the proportion of diagnosed UTIs that conform to accepted diagnostic criteria: >10,000 CFU/mL of one organism with pyuria, or >50,000 CFU/mL of one organism regardless of pyuria. The guideline was implemented in a level III NICU. Adherence, results, and complications were monitored for 12 months.

RESULTS

Guideline adherence after implementation was favorable, as evidenced by increased adoption of urinalysis with microscopy. There was a non-significant increase in diagnostic adherence to criteria, 87% to 93%, and non-significant decrease in the rate of UTI diagnosis, 39% to 36%. Complications were not significantly changed. Most UTIs were due to gram-negative rods, especially E. coli; Enterococcus was a common contaminant.

CONCLUSIONS

A guideline for diagnosing UTIs can safely increase uniformity. In contrast to previously published results, no significant changes were seen in the rate of UTI or the proportion of diagnoses conforming to the criteria for UTI. It is likely that guideline effects depend on the established practices of NICU providers. Additionally, a consistent pattern was seen in which organisms were more likely to be judged the source of true UTIs or contaminated cultures, meriting further study.

Pharmacokinetic and Pharmacodynamic Considerations of Antibiotic Use in Neonates

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

Unraveling the mechanism of ceftaroline-induced allosteric regulation in penicillin-binding protein 2a: insights for novel antibiotic development against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) acquires high-level resistance against β-lactam antibiotics by expressing penicillin-binding protein 2a (PBP2a). PBP2a is a cell wall-synthesizing protein whose closed active site exhibits a reduced binding affinity toward β-lactam antibiotics. Ceftaroline (CFT), a fifth-generation cephalosporin, can effectively inhibit the PBP2a activity by binding to an allosteric site to trigger the active site opening, allowing a second CFT to access the active site. However, the essential mechanism behind the allosteric behavior of PBP2a remains unclear. Herein, computational simulations are employed to elucidate how CFT allosterically regulates the conformation and dynamics of the active site of PBP2a. While CFT stabilizes the allosteric domain surrounding it, it simultaneously enhances the dynamics of the catalytic domain. Specifically, the study successfully captured the opening process of the active pocket in the allosteric CFT-bound systems and discovered that CFT alters the potential signal-propagating pathways from the allosteric site to the active site. These findings reveal the implied mechanism of the CFT-mediated allostery in PBP2a and provide new insights into dual-site drug design or combination therapy against MRSA targeting PBP2a.

Antimicrobial Resistance Pattern and Empirical Antibiotic Treatments in Neonatal Sepsis: A Retrospective, Single-Center, 12-Year Study

Neonatal sepsis is an important cause of morbidity and mortality in neonatal intensive care units (NICUs). Continuous evaluation of antimicrobial resistance (AMR) profiles is advised to implement antimicrobial stewardship (AMS) programs and establish effective empiric antibiotic protocols. AMS may reduce AMR in NICUs and improve sepsis outcomes. In this retrospective observational study, we report data on culture-positive neonatal sepsis, assessing differences after the implementation of an AMS program (2011-2016 vs. 2017-2022). A total of 215 positive bacterial cultures from 169 infants were retrieved, with 79 early-onset (36.7%) and 136 late-onset (63.3%) sepsis episodes. Frequent causative agents for early-onset sepsis were S. agalactiae and E. coli, all susceptible to empiric treatment. Late-onset sepsis was mainly caused by Enterobacterales and S. aureus. Aminoglycosides, cefotaxime, and piperacillin-tazobactam resistance among Enterobacterales was substantially low; S. aureus was mostly susceptible to oxacillin and vancomycin. There were no differences in mortality and multidrug-resistant pathogens rates between the two study periods. There were five episodes of fungal late-onset sepsis, mostly due to C. albicans, of which one was fatal. The microbial distribution pattern and AMR profiles overlapped with other European studies. Because susceptibility patterns are rapidly changing worldwide, with the emerging threat of Methicillin-resistant S. aureus and extended-spectrum beta-lactamases producers, infection prevention and control practices and AMS strategies require continuous optimization to limit selection pressure and AMR escalation.

Microbial associations and transfers across the One Health Triad effects on human and animal adiposity and temperament: a protocol for an observational pilot study

Introduction

It is known that humans and pet dogs harbor microbial communities that are important regulators of health and disease. Pet dogs have been shown to promote microbial exchange between members of a household, a process that may have lasting health implications. Infancy marks a unique period of development as environmental exploration and introduction to complementary foods occur. This may lead to greater opportunities for microbial transfer between pet dogs and human infants due to a more confined shared environment, similar means of mobility, greater physical contact, and increased frequency of shared foods. This human-animal bond has led to extensive research in the areas of childhood allergies and behavioral health; however, there is a paucity in the available literature that has evaluated how this unique ecological relationship may impact both human and animal health.

Methods

Infants who reside in a household with a pet dog will be recruited from the greater Phoenix metropolitan area for this longitudinal, observational pilot study and followed through the complementary feeding period. Infant and pet dog fecal, salivary, and skin samples, as well as environmental samples from feeding areas/surfaces and main indoor play areas from both infants and pet dogs will be collected through in-home visits before (~5 mos), during (~9 mos), and after (~12 mos) the complementary feeding (CF) period. Anthropometrics, temperament, and dietary habits of both infants and pet dogs along with assessment of the home condition will also be collected. Microbial comparisons between infant and pet dog samples and evaluation of microbial changes during the CF period will be evaluated. Further, we will assess relationships between microbial composition and adiposity and temperament of both infants and pet dogs.

Discussion

The proposed observational pilot study will advance the available science by exploring how microbial communities are associated and change between infants and pet dogs before, during, and after the CF period, a unique period of human growth and development. Findings from this study will provide insights into the impact these ecological relationships have on each other and how transfer across the One Health Triad impacts human and animal health.

Lumbar Puncture and Meningitis in Infants with Proven Early- or Late-Onset Sepsis: An Italian Prospective Multicenter Observational Study

Background: To evaluate the rates of lumbar puncture (LP) in infants with culture-proven sepsis. Study design: We prospectively enrolled 400 infants with early- or late-onset sepsis due to Group B streptococcus (GBS) or Eschericha coli, diagnosed within 90 days of life. Rates of LP and potential variables associated with LP performance were evaluated. Moreover, cerebrospinal fluid (CSF) characteristics and results of the molecular analysis were investigated. Results: LP was performed in 228/400 (57.0%) infants; 123/228 LPs (53.9%) were performed after antibiotic initiation, hampering the ability to identify the pathogen in the CSF culture. However, polymerase chain reaction increased the probability of positive results of CSF analysis compared to microbiological culture (28/79, 35.4% vs. 14/79, 17.7%, p = 0.001). Severe clinical presentation and GBS infection were associated with higher LP rates. The rate of meningitis was 28.5% (65/228). Conclusions: Rates of LP are low in culture-proven neonatal sepsis and antibiotics are frequently given before LP is carried out. Thus meningitis may be underestimated, and the chances of giving an effective therapy to the newborn are reduced. LP should be performed before the start of antibiotics when there is a clinical suspicion of infection.