A Correlation Study of the Microbiota Between Oral Cavity and Tonsils in Children With Tonsillar Hypertrophy

Diagnostic Efficiency of Tongue-Coating Microbiome in Patients With SARS-CoV-2 Omicron Variant Infection and Recovery

SARS-CoV-2 variants still pose threats to human public health. However, there has been little research regarding alterations in the tongue-coating microbiome in patients infected with the Omicron variant (PIOVs). Herein, we collected 963 tongue-coating samples prospectively, including 349 samples from PIOVs, 242 samples from recovered PIOVs, 300 samples from healthy controls (HCs) and 72 samples from patients infected with the original strain (PIOSs). We randomly selected tongue-coating samples from PIOVs and HCs as the discovery cohort and validation cohort. Tongue-coating microbiota was analyzed using Miseq sequencing. Our results showed that the tongue-coating microbial diversity of PIOVs was increased. We found that in PIOVs, the abundance was increased in 20 genera, including Prevonella and Atopobium, while the abundance was decreased in 23 genera, including Neisseria and Haemophilus. The classifier based on six optimal microbial markers had high diagnostic efficiency in the discovery cohort (area under the curve of 97.73%) and the validation cohort (area under the curve of 93.06%) between the PIOV and HC groups. Importantly, compared with PIOSs, PIOVs showed an increase in Fusobacterium. Recovery of patients was associated with the restoration of the tongue-coating microbiota. In conclusion, this study is the first to characterize the tongue-coating microbiota in PIOVs and to construct noninvasive diagnostic models, providing new strategies for the prevention and control of coronavirus variants.

Epstein-Barr virus in tonsillar tissue of Iranian children with tonsillar hypertrophy: Quantitative measurement by real-time PCR

Background and Objectives

Epstein-Barr virus (EBV) infection is ubiquitous all around the world. Tonsils seem to be candidate replication sites for EBV, and these tissues can be infected acutely or chronically. Some studies reported an association between EBV infection and tonsillar hypertrophy. In this study, we aimed to evaluate the presence and copy number of the EBV genome in tonsil tissue specimens of patients with tonsillar hypertrophy.

Methods

A cross-sectional study was performed on 50 fresh tonsil tissue samples from children, who underwent tonsillectomy because of tonsillar hypertrophy. Patients' tonsil tissues were evaluated using real-time polymerase chain reaction for EBV genome and viral load. Finally, the results were analyzed using SPSS software.

Results

EBV genome was detected in 58% (29/50) of tonsillar tissues. The relationship between EBV genome detection rate and age groups was in the statistical significance range (P = 0.051). Among 29 positive cases, the average EBV viral load was (3.1 × 105) copy/g ± (0.5 × 105) copy/g. No significant difference was observed among different sex and age groups for EBV viral load.

Conclusion

Herein, EBV genome detection could support the colonization of EBV in the tonsils, which may have a direct or indirect association with the pathogenesis of tonsillar hypertrophy.

Differences in salivary microbiome among children with tonsillar hypertrophy and/or adenoid hypertrophy

Children diagnosed with severe tonsillar hypertrophy display discernible craniofacial features distinct from those with adenoid hypertrophy, prompting illuminating considerations regarding microbiota regulation in this non-inflammatory condition. The present study aimed to characterize the salivary microbial profile in children with tonsillar hypertrophy and explore the potential functionality therein. A total of 112 children, with a mean age of 7.79 ± 2.41 years, were enrolled and divided into the tonsillar hypertrophy (TH) group (n = 46, 8.4 ± 2.5 years old), adenoid hypertrophy (AH) group (n = 21, 7.6 ± 2.8 years old), adenotonsillar hypertrophy (ATH) group (n = 23, 7.2 ± 2.1 years old), and control group (n = 22, 8.6 ± 2.1 years old). Unstimulated saliva samples were collected, and microbial profiles were analyzed by 16S rRNA sequencing of V3-V4 regions. Diversity and composition of salivary microbiome and the correlation with parameters of overnight polysomnography and complete blood count were investigated. As a result, children with tonsillar hypertrophy had significantly higher α-diversity indices (P＜0.05). β-diversity based on Bray-Curtis distance revealed that the salivary microbiome of the tonsillar hypertrophy group had a slight separation from the other three groups (P＜0.05). The linear discriminant analysis effect size (LEfSe) analysis indicated that Gemella was most closely related to tonsillar hypertrophy, and higher abundance of Gemella, Parvimonas, Dialister, and Lactobacillus may reflect an active state of immune regulation. Meanwhile, children with different degrees of tonsillar hypertrophy shared similar salivary microbiome diversity. This study demonstrated that the salivary microbiome in pediatric tonsillar hypertrophy patients had different signatures, highlighting that the site of upper airway obstruction primarily influences the salivary microbiome rather than hypertrophy severity.IMPORTANCETonsillar hypertrophy is the most frequent cause of upper airway obstruction and one of the primary risk factors for pediatric obstructive sleep apnea (OSA). Studies have discovered that children with isolated tonsillar hypertrophy exhibit different craniofacial morphology features compared with those with isolated adenoid hypertrophy or adenotonsillar hypertrophy. Furthermore, characteristic salivary microbiota from children with OSA compared with healthy children has been identified in our previous research. However, few studies provided insight into the relationship between the different sites of upper airway obstruction resulting from the enlargement of pharyngeal lymphoid tissue at different sites and the alterations in the microbiome. Here, to investigate the differences in the salivary microbiome of children with tonsillar hypertrophy and/or adenoid hypertrophy, we conducted a cross-sectional study and depicted the unique microbiome profile of pediatric tonsillar hypertrophy, which was mainly characterized by a significantly higher abundance of genera belonging to phyla Firmicutes and certain bacteria involving in the immune response in tonsillar hypertrophy, offering novel perspectives for future related research.

Denture microbiome shift and changes of salivary inflammatory markers following insertion of 3D printed removable partial PMMA denture: a pilot study

BACKGROUND

The aim of this study was to investigate the microbiome shift of denture biofilm formation, the incidence of Candida and changes of salivary inflammatory markers following insertion of 3-dimensional printed PMMA denture.

METHODS

This was a pilot study of 6 patients provided with 3D printed (test group) or conventionally heat-cured (control group) removable partial acrylic dentures followed up for 6 weeks. 3 denture swabs were collected at week 1, 3 and 6; and saliva samples were collected at baseline, week 1, 3 and 6 following denture insertion. Microbial DNA was isolated, and the 16S rRNA gene was amplified and sequenced to assess the denture microbiota. The presence of Candida was determined using PCR assay. The levels of salivary biomarkers lactoferrin (LTF) and histatin (HTN) were determined using ELISA.

RESULTS

Denture microbiome of both groups exhibited similar microbial compositions at weeks 1, 3 and 6. However, the percentage of Streptococcus in the test group was significantly lower at week 1 (p < 0.05). Greater bacterial diversity was detected in the test group (p < 0.05; pairwise Wilcoxon) after 6 weeks. The presence of Candida was only detected in one sample of the 3D printed denture (test group) after 6 weeks. The level of LTF biomarkers increased in both groups after 6 weeks, however, the level of HTN increased only in the control group.

CONCLUSIONS

Denture microbiome of both groups demonstrated similar microbial compositions. After 6 weeks, 3D printed denture demonstrated higher diversity with delayed microbiome shift compared to conventional heat cure dentures. 3D printed denture may be a viable alternative to conventional denture and it has a potential to delay microbial dysbiosis.

CLINICAL RELEVANCE

Among wearers, 3D printed denture can potentially reduce the risk of denture stomatitis. A greater diversity may delay or slow the transition of denture microbiome to dysbiosis.

Interkingdom biofilm of Streptococcus pyogenes and Candida albicans: establishment of an in vitro model and dose-response validation of antimicrobials

Although Streptococcus pyogenes and Candida albicans may colonize tonsillar tissues, the interaction between them in mixed biofilms has been poorly explored. This study established an interkingdom biofilm model of S. pyogenes and C. albicans and verified the dose-response validation of antimicrobials. Biofilms were formed on microplates, in the presence or absence of a conditioning layer of human saliva, using Brain Heart Infusion (BHI) broth or artificial saliva (AS) as a culture medium, and with variations in the microorganism inoculation sequence. Biofilms grown in AS showed higher mass than those grown in BHI broth, and an opposite trend was observed for metabolism. The number of S. pyogenes colonies was lower in AS. Amoxicillin and nystatin showed dose-dependent effects. The inoculation of the two species at the same time, without prior exposure to saliva, and using BHI broth would be the model of choice for future studies assessing the effects of antimicrobials on dual S. pyogenes/C. albicans biofilms.

The prevalence of dental caries and its associated factors among preschool children in Huizhou, China: a cross-sectional study

Background

Dental caries among preschool children were prevalent worldwide and had a significant impact on children and their families. Understanding its prevalence and risk factors helps to optimize the delivery of oral health care to the target population and promote their oral health ultimately. This cross-sectional study aimed to examine the prevalence of dental caries and its associated factors among 3- to 5-year-old children in Huizhou, Guangdong Province, China.

Method

We recruited children from 21 kindergartens adopting multistage sampling method. Two examiners performed oral examination. They assessed children's dental caries experience following the World Health Organization criteria. Children's dental caries activity, malocclusion, tonsil size and pH value of saliva were evaluated. Parental questionnaires collected child's sociodemographic background and oral-health-related behaviors. Data were analyzed by univariate analysis and logistic regression using SPSS.

Results

This study invited 1,485 children and recruited 1,348 (53.2% boys) (response rate: 90.8%). Dental caries prevalence rate was 58.2% for 3-, 70.7% for 4-, 80.5% for 5-year-old and 72.9% for all recruited children. The mean dmft score (±SD) was 3.38 (±4.26) for 3-, 4.75 (±4.96) for 4-, 5.81 (±5.71) for 5-year-old and 4.99 (±5.02) for all children. Age, family status (singleton or not), monthly family income, mother and father's education level, tonsil grading score, spacing in dentition, Cariostat score (reflecting the caries activity), dental plaque index, duration of breastfeeding, dental visit experience, tooth brushing habits and sugary snacking before sleeping were statistically related to the prevalence of dental caries (p < 0.050) in univariate analysis. These factors were further analyzed in the regression model. The results of the final model indicated dental caries were associated with age (p < 0.001), Cariostat score (p < 0.001), spacing (p < 0.001), tonsil grading score (p = 0.013), singleton or not (p = 0.002), sugary snacking habit before bed (p < 0.001) and breast-feeding duration (p = 0.050).

Conclusion

Dental caries was prevalent among 3-to 5-year-old preschool children in Huizhou, China. Children's age, caries activity, tonsil size, malocclusion, family background, sugary snacking habit and breast-feeding habit were related to the prevalence of dental caries. More emphasis should be placed on prevention targeting the risk factors from early life.

Genetic evidence strengthens the connection between gut microbiota and gingivitis: a two-sample Mendelian randomization study

Introduction

The oral cavity and gut tract, being interconnected and rich in microbiota, may have a shared influence on gingivitis. However, the specific role of distinct gut microbiota taxa in gingivitis remains unexplored. Utilizing Mendelian Randomization (MR) as an ideal method for causal inference avoiding reverse causality and potential confounding factors, we conducted a comprehensive two-sample MR study to uncover the potential genetic causal impact of gut microbiota on gingivitis.

Methods

Instrumental variables were chosen from single nucleotide polymorphisms (SNPs) strongly associated with 418 gut microbiota taxa, involving 14,306 individuals. Gingivitis, with 4,120 cases and 195,395 controls, served as the outcome. Causal effects were assessed using random-effect inverse variance-weighted, weighted median, and MR-Egger methods. For replication and meta-analysis, gingivitis data from IEU OpenGWAS were employed. Sensitivity analyses included Cochran's Q tests, funnel plots, leave-one-out analyses, and MR-Egger intercept tests. This study aimed to assess the genetic correlation between the genetically predicted gut microbiota and gingivitis using linkage disequilibrium score regression (LDSC).

Results

Three gut microbiota taxa (class Actinobacteria id.419, family Defluviitaleaceae id.1924, genus Defluviitaleaceae UCG011 id.11287) are predicted to causally contribute to an increased risk of gingivitis (P< 0.05). Additionally, four gut microbiota taxa (class Actinobacteria id.419, genus Escherichia Shigella id.3504, genus Ruminococcaceae UCG002 id.11360) potentially exhibit inhibitory causal effects on the risk of gingivitis (P< 0.05). No significant evidence of heterogeneity or pleiotropy is detected. Our findings indicate a suggestive genetic correlation between class Actinobacteria id.419, class Bacteroidia id.912, family Defluviitaleaceae id.1924, genus Escherichia Shigella id.3504 and gingivitis.

Conclusion

Our study establishes the genetic causal effect of 418 gut microbiota taxa on gingivitis, offering insights for clinical interventions targeting gingivitis. Subsequent research endeavors are essential to corroborate the findings of our present study.

Host microbiome-pathogen interactions in pediatric infections

PURPOSE OF REVIEW

In this review, we discuss recent research that has furthered our understanding of microbiome development during childhood, the role of the microbiome in infections during this life stage, and emerging opportunities for microbiome-based therapies for infection prevention or treatment in children.

RECENT FINDINGS

The microbiome is highly dynamic during childhood and shaped by a variety of host and environmental factors. In turn, the microbiome influences risk and severity of a broad range of infections during childhood, with recent studies highlighting potential roles in respiratory, gastrointestinal, and systemic infections. The microbiome exerts this influence through both direct interactions with potential pathogens and indirectly through modulation of host immune responses. The elucidation of some of these mechanisms by recent studies and the development of effective microbiome-based therapies for adults with recurrent Clostridioides difficile infection highlight the enormous promise that targeting the microbiome has for reducing the burden of infectious diseases during childhood.

SUMMARY

The microbiome has emerged as a key modifier of infection susceptibility and severity among children. Further research is needed to define the roles of microbes other than bacteria and to elucidate the mechanisms underlying microbiome-host and microbiome-pathogen interactions of importance to infectious diseases in children.

Distribution of serum uric acid concentration and its association with lipid profiles: a single-center retrospective study in children aged 3 to 12 years with adenoid and tonsillar hypertrophy

BACKGROUND

Presently, there is no consensus regarding the optimal serum uric acid (SUA) concentration for pediatric patients. Adenoid and tonsillar hypertrophy is considered to be closely associated with pediatric metabolic syndrome and cardiovascular risk and is a common condition in children admitted to the hospital. Therefore, we aimed to evaluate the relationship between SUA and dyslipidemia and propose a reference range for SUA concentration that is associated with a healthy lipid profile in hospitalized children with adenoid and tonsillar hypertrophy.

METHODS

Preoperative data from 4922 children admitted for elective adenoidectomy and/or tonsillectomy surgery due to adenoid and tonsillar hypertrophy were collected. SUA concentrations were scaled to standard deviation (SD), and SUA deviations were expressed as SD from the mean SUA of children without dyslipidemia.

RESULTS

The mean SUA concentration of the participants was 4.27 ± 1.01 mg/dL, and the prevalence of hyperuricemia was 1.6% when it was defined using an SUA of ≥ 7.0 mg/dL. Participants with dyslipidemia (856, 17.4%) had a higher prevalence of hyperuricemia (3.4% vs. 1.2%, P < 0.001) and higher SUA concentrations (4.51 ± 1.15 vs. 4.22 ± 0.97 mg/dL, P < 0.001) than those with ortholiposis. The circulating lipid status of participants with SUAs < 1 SD below the mean value for the participants with ortholiposis (range 1.80-3.28 mg/dL) was more normal. Each 1-SD increase in SUA was associated with a 27% increase in the risk of dyslipidemia (OR = 1.270, 95% CI, 1.185-1.361). Adjustment for a number of potential confounders reduced the strength of the relationship, but this remained significant (OR = 1.125, 95% CI, 1.042-1.215). The higher risk of dyslipidemia was maintained for participants with SUAs > 1 SD above the mean value of the participants with ortholiposis.

CONCLUSIONS

SUA was independently associated with dyslipidemia in children with adenoid and tonsillar hypertrophy, and an SUA < 1 SD below the mean value for patients with ortholiposis was associated with a healthy lipid profile.

Isolation and Characterization of the Lytic Pseudoxanthomonas kaohsiungensi Phage PW916

The emergence of multidrug-resistant bacterial pathogens poses a serious global health threat. While patient infections by the opportunistic human pathogen Pseudoxanthomonas spp. have been increasingly reported worldwide, no phage associated with this bacterial genus has yet been isolated and reported. In this study, we isolated and characterized the novel phage PW916 to subsequently be used to lyse the multidrug-resistant Pseudoxanthomonas kaohsiungensi which was isolated from soil samples obtained from Chongqing, China. We studied the morphological features, thermal stability, pH stability, optimal multiplicity of infection, and genomic sequence of phage PW916. Transmission electron microscopy revealed the morphology of PW916 and indicated it to belong to the Siphoviridae family, with the morphological characteristics of a rounded head and a long noncontractile tail. The optimal multiplicity of infection of PW916 was 0.1. Moreover, PW916 was found to be stable under a wide range of temperatures (4–60 °C), pH (4–11) as well as treatment with 1% (v/w) chloroform. The genome of PW916 was determined to be a circular double-stranded structure with a length of 47,760 bp, containing 64 open reading frames that encoded functional and structural proteins, while no antibiotic resistance nor virulence factor genes were detected. The genomic sequencing and phylogenetic tree analysis showed that PW916 was a novel phage belonging to the Siphoviridae family that was closely related to the Stenotrophomonas phage. This is the first study to identify a novel phage infecting the multidrug-resistant P. kaohsiungensi and the findings provide insight into the potential application of PW916 in future phage therapies.