Resilience and stability of the CF- intestinal and respiratory microbiome during nutritional and exercise intervention.

BACKGROUND: Impaired respiratory and intestinal microbiome composition is linked to cystic fibrosis lung disease severity. In people with cystic fibrosis (pwCF), regular exercise is recommended to delay disease progression and preserve a stable lung function. An optimal nutritional status is vital for best clinical outcomes. Our study investigated whether regular and monitored exercise and nutritional support promotes CF microbiome health. METHODS: A personalized nutrition and exercise program promoted nutritional intake and physical fitness in 18 pwCF for 12 months. Throughout the study, patients performed strength and endurance training monitored by a sports scientist via an internet platform. After three months, food supplementation with Lactobacillus rhamnosus LGG was introduced. Nutritional status and physical fitness were assessed before the study started, after three and nine months. Sputum and stool were collected, and microbial composition was analyzed by 16S rRNA gene sequencing. RESULTS: Sputum and stool microbiome composition remained stable and highly specific to each patient during the study period. Disease-associated pathogens dominated sputum composition. Lung disease severity and recent antibiotic treatment had the highest impact on taxonomic composition in stool and sputum microbiome. Strikingly, the long-term antibiotic treatment burden had only a minor influence. CONCLUSION: Despite the exercise and nutritional intervention, respiratory and intestinal microbiomes proved to be resilient. Dominant pathogens drove the composition and functionality of the microbiome. Further studies are required to understand which therapy could destabilize the dominant disease-associated microbial composition of pwCF.

Meconium Microbiome of Very Preterm Infants across Germany.

Meconium constitutes infants' first bowel movements postnatally. The consistency and microbial load of meconium are different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with negative health outcomes, but its composition is not well described, especially in preterm infants. Here, we characterized the meconium microbiomes from 330 very preterm infants (gestational ages 28 to 32 weeks) from 15 hospitals in Germany and in fecal samples from a subset of their mothers (N = 217). Microbiome profiles were compiled using 16S rRNA gene sequencing with negative and positive controls. The meconium microbiome was dominated by Bifidobacterium, Staphylococcus, and Enterococcus spp. and was associated with gestational age at birth and age at sample collection. Bifidobacterial abundance was negatively correlated with potentially pathogenic genera. The amount of bacterial DNA in meconium samples varied greatly across samples and was associated with the time since birth but not with gestational age or hospital site. In samples with low bacterial load, human mitochondrial sequences were highly amplified using commonly used, bacterial-targeted 16S rRNA primers. Only half of the meconium samples contained sufficient bacterial material to study the microbiome using a standard approach. To facilitate future meconium studies, we present a five-level scoring system ("MecBac") that predicts the success of 16S rRNA bacterial sequencing for meconium samples. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies. IMPORTANCE Meconium is present in the intestines of infants before and after birth and constitutes their first bowel movements postnatally. The consistency, composition and microbial load of meconium is largely different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with short-term and long-term negative health outcomes, but its composition is not yet well described, especially in preterm infants. We provide a characterization of the microbiome structure and composition of infant meconium and maternal feces from a large study cohort and propose a method to evaluate meconium samples for bacterial sequencing suitability. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies.

Containment of a Large SARS-CoV-2 Outbreak Among Healthcare Workers in a Pediatric Intensive Care Unit.

OBJECTIVE: Healthcare workers (HCWs) are particularly exposed SARS-CoV-2 because they are critical in preventing viral transmission and treating COVID-19 patients. Within HCWs, personnel of intensive care units (ICUs) are at the forefront of treating patients with a severe course of COVID-19 infection and therefore represent an extremely vulnerable group. Thus, our objective is to contribute to establish means of infection control protecting HCWs in the frontline of the current pandemic. DESIGN: An outbreak of SARS-CoV-2 was detected and contained in a pediatric ICU (PICU). The first positive case was identified with a point-of-care diagnostic system on site. Real-time PCR-based testing systems from self-collected nasopharyngeal samples swabs were used to test for viral RNA of SARS-CoV-2 in the follow-up. SETTING: PICU within a tertiary university hospital in Germany. PARTICIPANTS: Healthcare workers of the PICU. INTERVENTIONS: Positive HCWs were sent into quarantine. Containment measures were implemented including wearing of surgical-masks, physical distancing and systematic testing. RESULTS: Among 432 HCWs, 91 (25%) were tested. Forty-five percent reported symptoms corresponding to characteristics of COVID-19. Of those, only 19,5% (8 HCWs) were tested positive for SARS-CoV-2. No infection occurred outside the PICU. After the implementation of containment measures, viral transmission was stopped. CONCLUSIONS: In the present study, a large outbreak within a team of healthcare workers of a PICU, affecting almost one fifth of the entire personnel is documented, along with detailed insights about how the outbreak was contained and how operability of the unit was maintained.