Neonates colonized with pathogenic bacteria in the airways have a low-grade systemic inflammation

Aptamer-functionalized graphene quantum dots combined with artificial intelligence detect bacteria for urinary tract infections

Objectives

Urinary tract infection is one of the most prevalent forms of bacterial infection, and prompt and efficient identification of pathogenic bacteria plays a pivotal role in the management of urinary tract infections. In this study, we propose a novel approach utilizing aptamer-functionalized graphene quantum dots integrated with an artificial intelligence detection system (AG-AI detection system) for rapid and highly sensitive detection of Escherichia coli (E. coli).

Methods

Firstly, graphene quantum dots were modified with the aptamer that can specifically recognize and bind to E. coli. Therefore, the fluorescence intensity of graphene quantum dots was positively correlated with the concentration of E. coli. Finally, the fluorescence images were processed by artificial intelligence system to obtain the result of bacterial concentration.

Results

The AG-AI detection system, with wide linearity (103-109 CFU/mL) and a low detection limit (3.38×102 CFU/mL), can effectively differentiate between E. coli and other urinary tract infection bacteria. And the result of detection system is in good agreement with MALDI-TOF MS.

Conclusions

The detection system is an accurate and effective way to detect bacteria in urinary tract infections.

Early life acute infections and risk for cow's milk protein allergy or atopic dermatitis at 6 months of age in high risk for allergy infants

Background

Early life infections (ELIs), encompassing both viral and bacterial types, occur within the first six months of life. Influenced by genetic host factors and environmental conditions, the relationship between ELIs and subsequent allergic manifestations, particularly cow's milk protein allergy (CMPA) and atopic dermatitis (AD), is complex and not fully understood.

Objective

The aim of the current study was to examine the potential interplay between nutrition, infections, and allergic manifestations in the first six months of life in infants with a family history of allergies, who were either exclusively breastfed (EBF) or fed a combination of breast milk and standard (SF) or partially hydrolyzed infant formula (pHF).

Methods

The Allergy Reduction Trial (ART) is a multicenter, randomized controlled trial involving 551 participants. From birth, these participants were divided into three groups: Exclusive Breastfeeding (EBF), Partially Hydrolyzed Formula (pHF), and Standard Formula (SF). ELIs, defined as viral and bacterial infections occurring during the first 6 months, and outcomes (AD, CMPA) were recorded through questionnaires (i.e., SCORAD and CоMiSS) and clinical assessments.

Results

The relative risk (RR) for CMPA in infants with ELIs was 0.20 (95% CI: 0.07-0.58), highlighting a protective effect of ELIs against CMPA development. Notably, the incidence of CMPA was significantly lower in infants who experienced ELIs compared to those without (3% vs. 13.4%, p = 0.001), with no cases of CMPA observed at 6 months in exclusively breastfed (EBF) infants with ELIs. For AD, a trend was observed where the incidence was lower in infants with ELIs who were fed with pHF at 6.5%, compared to those fed with SF at 18.2% (p = 0.092), suggesting a potential protective effect of ELIs in the pHF group against AD development.

Conclusion

The study highlights a potential protective role of ELIs in reducing the risk of CMPA, particularly in EBF infants. Furthermore, it suggests a trend towards lower AD incidence in infants fed with pHF, highlighting the complex interplay between early microbial exposures, feeding practices, and immune development. Further research is warranted to unravel this challenging relationship and appropriately inform early life allergy prevention strategies.

Salivary polyreactive antibodies and Haemophilus influenzae are associated with respiratory infection severity in young children with recurrent respiratory infections

BACKGROUND

Recurrent respiratory tract infections (rRTIs) are a common reason for immunodiagnostic testing in children, which relies on serum antibody level measurements. However, because RTIs predominantly affect the respiratory mucosa, serum antibodies may inaccurately reflect local immune defences. We investigated antibody responses in saliva and their interplay with the respiratory microbiota in relation to RTI severity and burden in young children with rRTIs.

METHODS

We conducted a prospective cohort study including 100 children aged <10 years with rRTIs, their family members and healthy healthcare professionals. Total and polyreactive antibody concentrations were determined in serum and saliva (ELISA); respiratory microbiota composition (16S rRNA sequencing) and respiratory viruses (quantitative PCR) were characterised in nasopharyngeal swabs. Proteomic analysis (Olink) was performed on saliva and serum samples. RTI symptoms were monitored with a daily mobile phone application and assessed using latent class analysis and negative binomial mixed models.

RESULTS

Serum antibody levels were not associated with RTI severity. Strikingly, 28% of salivary antibodies and only 2% of serum antibodies displayed polyreactivity (p<0.001). Salivary polyreactive IgA was negatively associated with recurrent lower RTIs (adjusted OR 0.80, 95% CI 0.67-0.94) and detection of multiple respiratory viruses (adjusted OR 0.76, 95% CI 0.61-0.96). Haemophilus influenzae abundance was positively associated with RTI symptom burden (regression coefficient 0.05, 95% CI 0.02-0.08).

CONCLUSION

These results highlight the importance of mucosal immunity in RTI severity and burden, and suggest that the level of salivary polyreactive IgA and H. influenzae abundance may serve as indicators of infection severity and burden in young children with rRTIs.

Genetic predisposition to high BMI increases risk of early life respiratory infections and episodes of severe wheeze and asthma

BACKGROUND

High body mass index (BMI) is an established risk factor for asthma, but the underlying mechanisms remain unclear.

OBJECTIVE

To increase understanding of the BMI-asthma relationship by studying the association between genetic predisposition to higher BMI and asthma, infections and other asthma traits during childhood.

METHODS

Data were obtained from the two ongoing Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts. Polygenic risk scores for adult BMI were calculated for each child. Replication was done in the large-scale register-based Integrative Psychiatric Research (iPSYCH) cohort using data on hospitalisation for asthma and infections.

RESULTS

In the COPSAC cohorts (n=974), the adult BMI polygenic risk score was significantly associated with lower respiratory tract infections (incidence rate ratio (IRR) 1.20, 95% CI 1.08-1.33, false discovery rate p-value (pFDR)=0.005) at age 0-3 years and episodes of severe wheeze (IRR 1.30, 95% CI 1.06-1.60, pFDR=0.04) at age 0-6 years. Lower respiratory tract infections partly mediated the association between the adult BMI polygenic risk score and severe wheeze (proportion mediated: 0.59, 95% CI 0.28-2.24, p-value associated with the average causal mediation effect (pACME)=2e-16). In contrast, these associations were not mediated through the child's current BMI and the polygenic risk score was not associated with an asthma diagnosis or reduced lung function up to age 18 years. The associations were replicated in iPSYCH (n=114 283), where the adult BMI polygenic risk score significantly increased the risk of hospitalisations for lower respiratory tract infections and wheeze or asthma throughout childhood to age 18 years.

CONCLUSION

Children with genetic predisposition to higher BMI had increased risk of lower respiratory tract infections and severe wheeze, independent of the child's current BMI. These results shed further light on the complex relationship between body mass BMI and asthma.

Mechanisms underlying the effects, and clinical applications, of oral microbiota in lung cancer: current challenges and prospects

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

A Chemical Structure and Machine Learning Approach to Assess the Potential Bioactivity of Endogenous Metabolites and Their Association with Early Childhood Systemic Inflammation

Metabolomics has gained much attention due to its potential to reveal molecular disease mechanisms and present viable biomarkers. This work uses a panel of untargeted serum metabolomes from 602 children from the COPSAC2010 mother-child cohort. The annotated part of the metabolome consists of 517 chemical compounds curated using automated procedures. We created a filtering method for the quantified metabolites using predicted quantitative structure-bioactivity relationships for the Tox21 database on nuclear receptors and stress response in cell lines. The metabolites measured in the children's serums are predicted to affect specific targeted models, known for their significance in inflammation, immune function, and health outcomes. The targets from Tox21 have been used as targets with quantitative structure-activity relationships (QSARs). They were trained for ~7000 structures, saved as models, and then applied to the annotated metabolites to predict their potential bioactivities. The models were selected based on strict accuracy criteria surpassing random effects. After application, 52 metabolites showed potential bioactivity based on structural similarity with known active compounds from the Tox21 set. The filtered compounds were subsequently used and weighted by their bioactive potential to show an association with early childhood hs-CRP levels at six months in a linear model supporting a physiological adverse effect on systemic low-grade inflammation.

Bacterial colonisation of the airway in neonates and risk of asthma and allergy until age 18 years

BACKGROUND

We previously showed an association between neonatal bacterial airway colonisation and increased risk of persistent wheeze/asthma until age 5 years. Here, we study the association with persistent wheeze/asthma and allergy-related traits until age 18 years.

METHODS

We investigated the association between airway colonisation with Streptococcus pneumoniae, Moraxella catarrhalis and/or Haemophilus influenzae in 1-month-old neonates from the COPSAC2000 mother-child cohort and the development of persistent wheeze/asthma and allergy-related traits longitudinally until age 18 years using generalised estimating equations. Replication was sought in the similarly designed COPSAC2010 cohort of 700 children.

RESULTS

Neonatal airway colonisation was present in 66 (21%) out of 319 children and was associated with a 4-fold increased risk of persistent wheeze/asthma (adjusted OR 4.01 (95% CI 1.76-9.12); p<0.001) until age 7 years, but not from age 7 to 18 years. Replication in the COPSAC2010 cohort showed similar results using 16S data. Colonisation was associated with an increased number of exacerbations (adjusted incidence rate ratio 3.20 (95% CI 1.38-7.44); p<0.01) until age 7 years, but not from age 7 to 18 years. Colonisation was associated with increased levels of blood eosinophils (adjusted geometric mean ratio 1.24 (95% CI 1.06-1.44); p<0.01) and tumour necrosis factor (TNF)-α (adjusted geometric mean ratio 1.09 (95% CI 1.02-1.16); p=0.01) until age 12 years. There were no associations with lung function, bronchial reactivity, fractional exhaled nitric oxide, allergic sensitisation, total IgE or atopic dermatitis up to age 18 years.

CONCLUSIONS

Neonatal airway colonisation was associated with early-onset persistent wheeze/asthma, exacerbations, elevated blood eosinophils and elevated TNF-α in blood, most prominent in early childhood, thereafter diminishing and no longer evident by age 18 years.

25 Years of translational research in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC)

The Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts have provided a foundation of 25 years of research on the origins, prevention, and natural history of childhood asthma and related disorders. COPSAC's approach is characterized by clinical translational research with longitudinal deep phenotyping and exposure assessments from pregnancy, in combination with multi-omic data layers and embedded randomized controlled trials. One trial showed that fish oil supplementation during pregnancy prevented childhood asthma and identified pregnant women with the highest benefits from supplementation, thereby creating the potential for personalized prevention. COPSAC revealed that airway colonization with pathogenic bacteria in early life is associated with an increased risk of asthma. Further, airway bacteria were shown to be a trigger of acute asthma-like symptoms, with benefit from antibiotic treatment. COPSAC identified an immature gut microbiome in early life as a risk factor for asthma and allergy and further demonstrated that asthma can be predicted by infant lung function. At a molecular level, COPSAC has identified novel susceptibility genes, early immune deviations, and metabolomic alterations associated with childhood asthma. Thus, the COPSAC research program has enhanced our understanding of the processes causing childhood asthma and has suggested means of personalized prevention and treatment.

Vertical Transfer of Metabolites Detectable from Newborn's Dried Blood Spot Samples Using UPLC-MS: A Chemometric Study

The pregnancy period and first days of a newborn's life is an important time window to ensure a healthy development of the baby. This is also the time when the mother and her baby are exposed to the same environmental conditions and intake of nutrients, which can be determined by assessing the blood metabolome. For this purpose, dried blood spots (DBS) of newborns are a valuable sampling technique to characterize what happens during this important mother-child time window. We used metabolomics profiles from DBS of newborns (age 2-3 days) and maternal plasma samples at gestation week 24 and postpartum week 1 from n=664 mother-child pairs of the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010) cohort, to study the vertical mother-child transfer of metabolites. Further, we investigated how persistent the metabolites are from the newborn and up to 6 months, 18 months, and 6 years of age. Two hundred seventy two metabolites from UPLC-MS (Ultra Performance Liquid Chromatography-Mass Spectrometry) analysis of DBS and maternal plasma were analyzed using correlation analysis. A total of 11 metabolites exhibited evidence of transfer (R>0.3), including tryptophan betaine, ergothioneine, cotinine, theobromine, paraxanthine, and N6-methyllysine. Of these, 7 were also found to show persistence in their levels in the child from birth to age 6 years. In conclusion, this study documents vertical transfer of environmental and food-derived metabolites from mother to child and tracking of those metabolites through childhood, which may be of importance for the child's later health and disease.

Associations of 25 Hydroxyvitamin D and High Sensitivity C-reactive Protein Levels in Early Life

Vitamin D deficiency and elevated high sensitivity C-reactive protein (hs-CRP) have been associated with several health outcomes, but knowledge on early life trajectories and association between 25 hydroxyvitamin D (25(OH)D) and hs-CRP is lacking. We investigated the association between longitudinal measurements of 25(OH)D and hs-CRP, respectively, from pregnancy to childhood and throughout childhood in two Danish mother–child cohorts—the COPSAC₂₀₁₀ and COPSAC₂₀₀₀. In COPSAC₂₀₁₀, there was an association between 25(OH)D concentrations at week 24 in pregnancy and at age 6 months in childhood (n = 633): estimate (95% CI); 0.114 (0.041;0.187), p = 0.002, and between 25(OH)D at age 6 months and 6 years (n = 475): 0.155 (0.083;0.228), p < 0.001. This was also demonstrated in the COPSAC₂₀₀₀ cohort between 25(OH)D concentrations in cord blood and at age 4 years (n = 188): 0.294 (0.127;0.461), p < 0.001 and at age 6 months and 4 years (n = 264): 0.260 (0.133;0.388), p < 0.001. In COPSAC₂₀₀₀, we also found an association between hs-CRP at age 6 months and 12 years in childhood (n = 232): 0.183 (0.076;0.289), p < 0.001. Finally, we found a negative association between the cross-sectional measurements of 25(OH)D and hs-CRP at age 6 months (n = 613) in COPSAC₂₀₁₀: −0.004 (−0.008;−0.0004), p = 0.030, but this was not replicated in COPSAC₂₀₀₀. In this study, we found evidence of associations across timepoints of 25(OH)D concentrations from mid-pregnancy to infancy and through childhood and associations between hs-CRP levels during childhood, although with weak correlations. We also found a negative cross-sectional association between 25(OH)D and hs-CRP concentrations in COPSAC₂₀₁₀ proposing a role of vitamin D in systemic low-grade inflammation, though this association was not present in COPSAC₂₀₀₀.

Management Strategies to Reduce Exacerbations in non-T2 Asthma

There have been considerable advances in our understanding of asthmatic airway inflammation, resulting in a paradigm shift of classifying individuals on the basis of either the presence or the absence of type 2 (T2) inflammatory markers. Several novel monoclonal antibody therapies targeting T2 cytokines have demonstrated significant clinical effects including reductions in acute exacerbations and improvements in asthma-related quality of life and lung function for individuals with T2-high asthma. However, there have been fewer advancements in developing therapies for those without evidence of T2 airway inflammation (so-called non-T2 asthma). Here, we review the heterogeneity of molecular mechanisms responsible for initiation and regulation of non-T2 inflammation and discuss both current and potential future therapeutic options for individuals with non-T2 asthma.

Airway bacterial carriage and childhood respiratory health: A population-based prospective cohort study

BACKGROUND

Airway bacterial carriage might play a role in respiratory disease. We hypothesize that nasal carriage with Staphylococcus aureus or nasopharyngeal carriage with Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae predisposes individuals to adverse respiratory health.

OBJECTIVE

To examine the association of early-life airway bacterial carriage with respiratory tract infections and vice versa, and of early-life airway bacterial carriage with wheezing, lung function, and asthma in later childhood.

METHODS

We collected upper airway swabs for bacterial culturing for S aureus, H influenzae, M catarrhalis, and H influenzae at six timepoints between the ages of 6 weeks and 6 years among 945 children participating in a population-based prospective cohort study. Information on respiratory tract infections and wheezing until age 6 years, and asthma at age 10 years was obtained by questionnaires. Lung function at age 10 years was measured by spirometry. We tested possible bidirectional associations between airway bacterial carriage and respiratory tract infections by cross-lagged models, and associations of repeatedly measured airway bacterial carriage with wheezing, lung function, and asthma by generalized estimating equations models and regression models.

RESULTS

Cross-lagged modeling showed that early-life airway bacterial carriage was not consistently associated with upper and lower respiratory tract infections or vice versa. Nasopharyngeal carriage with any bacteria in infancy was associated with an increased risk of wheezing (OR [95% CI]: 1.66 [1.31, 2.10]). Airway bacterial carriage was not consistently associated with school-age lung function or asthma.

CONCLUSION

Nasopharyngeal carriage with any bacteria is associated with wheezing, but not respiratory tract infections, asthma, or lung function.

Cytokines and Chemokines as Biomarkers of Future Asthma

Antenatal and preschool factors are key in determining the progression to pre-school wheeze and eosinophilic school age asthma. The conventional view of eosinophilic asthma is that airway inflammation is the fundamental underlying abnormality, and airway inflammation and hyper-responsiveness are secondary; in fact, these three are parallel processes. Very early structural changes, independent of inflammation and infection, are associated with early airway hyper-responsiveness and later adverse respiratory outcomes. There is a bidirectional relationship between structural airway wall changes and airway inflammation, with airway contraction per se leading to the release of growth factors, and inflammatory pathways promoting airway remodeling. Early viral infection (and increasingly being appreciated, bacterial infection) is important in wheeze outcomes. There is evidence of abnormal immune function including cytokine release before the onset of viral infections. However, viral infections may also have prolonged effects on the host immune system, and the evidence for beneficial and adverse effects of viral infection is conflicting. In older children and adults, asthmatic epithelial cells show impaired interferon responses to viral infection, but only in the presence of uncontrolled type 2 inflammation, implying these are secondary phenomena. There are also compelling data relating the innate immune system to later asthma and atopy, and animal studies suggest that the effects of a high endotoxin, microbiologically diverse environment may be modulated via the epithelial alarmin IL-33. Whereas, previously only viral infection was thought to be important, early bacterial colonization of the upper airway is coming to the fore, associated with a mixed pattern of TH1/TH2/TH17 cytokine secretion, and adverse long term outcomes. Bacterial colonization is probably a marker of a subtle immune deficiency, rather than directly causal. The airway and gut microbiome critically impacts the development of Type 2 inflammatory responses. However, Type 2 inflammatory cytokines, which are critical both to progression from pre-school wheeze to eosinophilic asthma, and sustaining the eosinophilic asthmatic state, are not implicated in the very early development of the disease. Taken together, the evidence is that the earliest cytokine and chemokine signals will come from the study of bronchial epithelial cell function and their interactions with viruses and the microbiome.

Recent developments and highlights in mechanisms of allergic diseases: Microbiome

All body surfaces are exposed to a wide variety of microbes, which significantly influence immune reactivity within the host. This review provides an update on some of the critical novel findings that have been published on the influence of the microbiome on atopic dermatitis, food allergy and asthma. Microbial dysbiosis has consistently been observed in the skin, gut and lungs of patients with atopic dermatitis, food allergy and asthma, respectively, and the role of specific microbes in allergic disorders is being intensively investigated. However, many of these discoveries have yet to be translated into routine clinical practice.

Respiratory Bordetella bronchiseptica Carriage is Associated with Broad Phenotypic Alterations of Peripheral CD4⁺CD25⁺ T Cells and Differentially Affects Immune Responses to Secondary Non-Infectious and Infectious Stimuli in Mice

The respiratory tract is constantly exposed to the environment and displays a favorable niche for colonizing microorganisms. However, the effects of respiratory bacterial carriage on the immune system and its implications for secondary responses remain largely unclear. We have employed respiratory carriage with Bordetella bronchiseptica as the underlying model to comprehensively address effects on subsequent immune responses. Carriage was associated with the stimulation of Bordetella-specific CD4⁺, CD8⁺, and CD4⁺CD25⁺Foxp3⁺ T cell responses, and broad transcriptional activation was observed in CD4⁺CD25⁺ T cells. Importantly, transfer of leukocytes from carriers to acutely B. bronchiseptica infected mice, resulted in a significantly increased bacterial burden in the recipient's upper respiratory tract. In contrast, we found that respiratory B. bronchiseptica carriage resulted in a significant benefit for the host in systemic infection with Listeria monocytogenes. Adaptive responses to vaccination and influenza A virus infection, were unaffected by B. bronchiseptica carriage. These data showed that there were significant immune modulatory processes triggered by B. bronchiseptica carriage, that differentially affect subsequent immune responses. Therefore, our results demonstrated the complexity of immune regulation induced by respiratory bacterial carriage, which can be beneficial or detrimental to the host, depending on the pathogen and the considered compartment.