Outbreak of group B Streptococcus in a neonatal care unit confirmed by whole-genome sequencing

AIM

Clusters of group B Streptococcus (GBS) infections in neonatal intensive care units (NICU) are poorly documented. We aimed to assess GBS cross-transmission during an outbreak of GBS sepsis.

METHODS

The study was carried out between October and November 2021 in a French University Hospital. Neonatal intensive care unit (NICU) patients with GBS sepsis were included. Clinical data were retrieved from electronic patient records. Group B Streptococcus isolates were characterized at the molecular level using capsular genotyping and whole-genome sequencing (WGS).

RESULTS

The outbreak of GBS sepsis affected three very preterm neonates with a gestational age of less than 26 weeks, including one recurrent male index case aged 26 days, and two female secondary cases aged 5 and 17 days. The microbiological investigation identified a GBS isolate of capsular type III and Sequence Type 17 as responsible for the four infectious episodes. Whole-genome sequencing confirmed the identity between the isolates. The outbreak and the results of the microbiological investigations led to an immediate reinforcement of hygiene measures.

CONCLUSION

Clustered cases of GBS infections in NICU and horizontal transmission of the hypervirulent GBS Sequence Type 17 are likely underestimated. Prospective investigation of all nosocomial cases using WGS should contribute to improving vigilance regarding GBS cross-transmission and infection prevention.

Nebulized curcumin protects neonatal lungs from antenatal insult in rats

Intrauterine growth restriction (IUGR) increases the risk of bronchopulmonary dysplasia (BPD), one of the major complications of prematurity. Antenatal low-protein diet (LPD) exposure in rats induces IUGR and mimics BPD-related alveolarization disorders. Peroxisome proliferator-activated receptor-γ (PPARγ) plays a key role in normal lung development and was found deregulated following LPD exposure. The objective of this article was to investigate the effects of nebulized curcumin, a natural PPARγ agonist, to prevent IUGR-related abnormal lung development. We studied rat pups antenatally exposed to an LPD or control diet (CTL) and treated with nebulized curcumin (50 mg/kg) or vehicle from postnatal (P) days 1 to 5. The primary readouts were lung morphometric analyses at P21. Immunohistochemistry (P21) and microarrays (P6 and P11) were compared within animals exposed to LPD versus controls, with and without curcumin treatment. Quantitative morphometric analyses revealed that LPD induced abnormal alveolarization as evidenced by a significant increase in mean linear intercept (MLI) observed in P21 LPD-exposed animals. Early curcumin treatment prevented this effect, and two-way ANOVA analysis demonstrated significant interaction between diet and curcumin both for MLI [F_(1,39) = 12.67, P = 0.001] and radial alveolar count at P21 [F_(1,40) = 6.065, P = 0.0182]. Immunohistochemistry for fatty acid binding protein 4 (FABP4), a major regulator of PPARγ pathway, showed a decreased FABP4⁺ alveolar cell density in LPD-exposed animals treated by curcumin. Transcriptomic analysis showed that early curcumin significantly prevented the activation of profibrotic pathways observed at P11 in LPD-exposed animals. Nebulized curcumin appears to be a promising strategy to prevent alveolarization disorders in IUGR rat pups, targeting pathways involved in lung development.

Glucocorticosteroids effects on brain development in the preterm infants: a role for microglia?

Prematurity, observed in 15 million births worldwide each year, is a clinical condition that is a major cause of neonatal mortality and morbidity in the short and long term. Preterm infants are at high risk of developing respiratory problems, sepsis, and other morbidities leading to neurodevelopmental impairment and neurobehavioral disorders. Perinatal glucocorticosteroids have been widely used for the prevention and treatment of adverse outcomes linked to prematurity. However, despite their short-term benefits due to their maturational properties, some clinical trials have shown an association between steroids exposure and abnormal brain development in infants born preterm. Neuroinflammation has emerged as a preeminent factor for brain injury in preterm infants, and the major role of microglia, the brain resident immune cells, has been recently highlighted. Considering the role of microglia in the modulation of brain development, the aim of this review is to summarize the effects of endogenous and exogenous glucocorticosteroids on brain development and discuss the possible role of microglia as the mediator of these effects.

Intravenous pulses of methylprednisolone for infants with severe bronchopulmonary dysplasia and respiratory support after 3 months of age

INTRODUCTION

There are few published data on the efficacy of systemic corticosteroids in preterm infants with very severe forms of bronchopulmonary dysplasia (BPD), requiring respiratory support after 3 months of age. The aim of this study was to report the use of pulses of methylprednisolone in this population and its consequences on the level of respiratory support.

METHODS

This retrospective monocentre study included infants over 3 months of age with severe BPD who received at least one pulse of methylprednisolone (300 mg/m² /day intravenous [IV] over 3 days). The primary outcome was the evolution of the pulmonary severity score (PSS) during the 3 months preceding and the 5 months following the first pulse. The evolution of the median PSS over time was analyzed using linear segmented regression for interrupted time series.

RESULTS

Ten infants were included. During the 3 months preceding the first pulse, a significant increase in the median PSS was observed (p = .01), followed by a progressive decrease during the 5 months after administration of the first pulse (p < .01). Greater effects were observed in more severe infants requiring mechanical or noninvasive ventilation than in those receiving supplemental oxygen through nasal cannula.

CONCLUSION

High-dose IV pulses of methylprednisolone were associated with a decrease in the level of respiratory support required by infants with very severe forms of BPD, with a greater effect in those on mechanical or noninvasive ventilation. Further studies are warranted to confirm these preliminary results and assess the long-term safety of this therapy.

Simulation Game Versus Multiple Choice Questionnaire to Assess the Clinical Competence of Medical Students: Prospective Sequential Trial

BACKGROUND

The use of simulation games (SG) to assess the clinical competence of medical students has been poorly studied.

OBJECTIVE

The objective of this study was to assess whether an SG better reflects the clinical competence of medical students than a multiple choice questionnaire (MCQ).

METHODS

Fifth-year medical students in Paris (France) were included and individually evaluated on a case of pediatric asthma exacerbation using three successive modalities: high-fidelity simulation (HFS), considered the gold standard for the evaluation of clinical competence, the SG Effic'Asthme, and an MCQ designed for the study. The primary endpoint was the median kappa coefficient evaluating the correlation of the actions performed by the students between the SG and HFS modalities and the MCQ and HFS modalities. Student satisfaction was also evaluated.

RESULTS

Forty-two students were included. The actions performed by the students were more reproducible between the SG and HFS modalities than between the MCQ and HFS modalities (P=.04). Students reported significantly higher satisfaction with the SG (P<.01) than with the MCQ modality.

CONCLUSIONS

The SG Effic'Asthme better reflected the actions performed by medical students during an HFS session than an MCQ on the same asthma exacerbation case. Because SGs allow the assessment of more dimensions of clinical competence than MCQs, they are particularly appropriate for the assessment of medical students on situations involving symptom recognition, prioritization of decisions, and technical skills.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03884114; https://clinicaltrials.gov/ct2/show/NCT03884114.