Microbial profiling of dental plaque from mechanically ventilated patients

Development and validation of a nomogram for oral mucosal membrane pressure injuries in ICU patients: A prospective cohort study

AIMS

Establishing a nomogram to estimate the probability of oral mucosal membrane pressure injury of endotracheal tube-intubated hospitalized patients in intensive care unit.

DESIGN

Multicentre prospective cohort study.

METHODS

Using Lasso regression and COX regression, variable selection was performed on demographic, clinical and laboratory data of 1037 ICU endotracheal tube-intubated hospitalized patients from West China Hospital, to construct a nomogram. External validation was conducted on 484 ICU endotracheal tube-intubated patients from People's Hospital of Zhongjiang County.

RESULTS

Among 38 potential predictors, five variables emerged as independent predictors, integrated into the nomogram: administration of antibiotics, nutritional therapy duration, agitation, hypotension and albumin levels.

CONCLUSIONS

We established a nomogram based on the hospital characteristics of ICU endotracheal tube-intubated patients, aiding in the prediction of the occurrence of oral mucosal membrane pressure injury.

REPORTING METHOD

The study followed TRIPOD guidelines.

RELEVANCE TO CLINICAL PRACTICE

The nomogram we developed can assist clinical worker in better identifying at-risk patients and risk factors. It enables the implementation of evidence-based nursing interventions in care to prevent the development of oral mucosal membrane pressure injury.

TRIAL REGISTRATION

The study has been registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn) under registration number ChiCTR2200056615.

In vitro investigation of relationship between quorum-sensing system genes, biofilm forming ability, and drug resistance in clinical isolates of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is an opportunistic pathogen in the health-care systems and one of the primary causative agents with high mortality in hospitalized patients, particularly immunocompromised. The limitation of effective antibiotic administration in multidrug-resistant and extensively drug-resistant P. aeruginosa isolates leads to the development of nosocomial infections and health problems. Quorum sensing system contributes to biofilm formation, expression of bacterial virulence factors, and development of drug resistance, causing prolonged patient infections. Therefore, due to the significance of the quorum sensing system in increasing the pathogenicity of P. aeruginosa, the primary objective of our study was to investigate the frequency of quorum sensing genes, as well as the biofilm formation and antibiotic resistance pattern among P. aeruginosa strains.

METHODS

A total of 120 P. aeruginosa isolates were collected from different clinical specimens. The disk diffusion method was applied to detect the antibiotic resistance pattern of P. aeruginosa strains. Also, the microtiter plate method was carried out to evaluate the biofilm-forming ability of isolates. Finally, the frequency of rhlI, rhlR, lasI, and lasR genes was examined by the polymerase chain reaction method.

RESULTS

In total, 88.3% P. aeruginosa isolates were found to be multidrug-resistant, of which 30.1% had extensively drug-resistant pattern. The highest and lowest resistance rates were found against ceftazidime (75.0%) and ciprofloxacin (46.6%), respectively. Also, 95.8% of isolates were able to produce biofilm, of which 42.5%, 33.3%, and 20.0% had strong, moderate, and weak biofilm patterns, respectively. The frequency of quorum sensing genes among all examined strains was as follows: rhlI (81.6%), rhlR (90.8%), lasI (89.1%), and lasR (78.3%). The most common type of quorum sensing genes among multidrug-resistant isolates were related to rhlR and lasI genes with 94.3%. Furthermore, rhlI, rhlR, and lasI genes were positive for all extensively drug-resistant isolates. However, the lasR gene had the lowest frequency among both multidrug-resistant (83.0%) and extensively drug-resistant (90.6%) isolates. Moreover, rhlR (94.7%) and lasR (81.7%) genes had the highest and lowest prevalence among biofilm-forming isolates, respectively.

CONCLUSION

Our findings disclosed the significantly high prevalence of drug resistance among P. aeruginosa isolates. Also, the quorum sensing system had a significant correlation with biofilm formation and drug resistance, indicating the essential role of this system in the emergence of nosocomial infections caused by P. aeruginosa.

Efficacy of Ceragenins in Controlling the Growth of Oral Microorganisms: Implications for Oral Hygiene Management

Ensuring proper dental hygiene is of paramount importance for individuals' general well-being, particularly for patients receiving medical care. There is a prevailing utilization of conventional oral hygiene items, including toothbrushes and mouthwashes, which have gained widespread acceptance; nevertheless, their limitations encourage investigating novel options in this domain. Our study indicates that ceragenins (CSAs) being lipid analogs of host defense peptides, well-recognized for their wide-ranging antimicrobial properties, may be a potentially efficacious means to augment oral hygiene in hospitalized individuals. We demonstrate that ceragenins CSA-13, CSA-44, and CSA-131 as well as undescribed to date CSA-255 display potent antimicrobial activities against isolates of fungi, aerobic, and anaerobic bacteria from Candida, Streptococcus, Enterococcus, and Bacteroides species, which are well-recognized representatives of microbes found in the oral cavity. These effects were further confirmed against mono- and dual-species fungal and bacterial biofilms. While the ceragenins showed similar or slightly diminished efficacy compared to commercially available mouthwashes, they demonstrated a highly favorable toxicity profile toward host cells, that may translate into better maintenance of host mucosal membrane stability. This suggests that incorporating ceragenins into oral hygiene products could be a valuable strategy for reducing the risk of both oral cavity-localized and secondary systemic infections and for improving the overall health outcomes of individuals receiving medical treatment.

The gut microbiota composition is linked to subsequent occurrence of ventilator-associated pneumonia in critically ill patients

Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in critically ill-ventilated patients. Oropharyngeal and lung microbiota have been demonstrated to be associated with VAP occurrence, but the involvement of gut microbiota has not been investigated so far. Therefore, the aim of this study is to compare the composition of the gut microbiota between patients who subsequently develop VAP and those who do not. A rectal swab was performed at admission of every consecutive patient into the intensive care unit (ICU) from October 2019 to March 2020. After DNA extraction, V3-V4 and internal transcribed spacer 2 regions deep-sequencing was performed on MiSeq sequencer (Illumina) and data were analyzed using Divisive Amplicon Denoising Algorithm 2 (DADA2) pipeline. Among 255 patients screened, 42 (16%) patients with invasive mechanical ventilation for more than 48 h were included, 18 (43%) with definite VAP and 24 without (57%). Patients who later developed VAP had similar gut bacteriobiota and mycobiota α-diversities compared to those who did not develop VAP. However, gut mycobiota was dissimilar (β-diversity) between these two groups. The presence of Megasphaera massiliensis was associated with the absence of VAP occurrence, whereas the presence of the fungal genus Alternaria sp. was associated with the occurrence of VAP. The composition of the gut microbiota, but not α-diversity, differs between critically ill patients who subsequently develop VAP and those who do not. This study encourages large multicenter cohort studies investigating the role of gut-lung axis and oropharyngeal colonization in the development of VAP in ICU patients. Trial registration number: NCT04131569, date of registration: 18 October 2019. IMPORTANCE The composition of the gut microbiota, but not α-diversity, differs between critically ill patients who subsequently develop ventilator-associated pneumonia (VAP) and those who do not. Investigating gut microbiota composition could help to tailor probiotics to provide protection against VAP.

Quantitative oral health assessments in mechanically ventilated patients: A scoping review

BACKGROUND

Oral health is a key contributor to a person's overall health. Previous studies indicate that oral health deteriorates throughout ventilation and may contribute to the development of ventilator-associated pneumonia (VAP). Oral health at the time of initial ventilation may impact on this deterioration.

AIMS

To determine the quantitative clinical assessment methods used to measure oral health and what is currently known regarding the oral health of patients at the time of initial ventilation.

STUDY DESIGN

A systematic literature search using electronic bibliographic databases MEDLINE/PubMed, Embase, CINAHL, and the Cochrane Library was undertaken for this scoping review. Studies were included if patients were >18 years old and mechanically ventilated for <48 h at the time of the first oral assessment.

RESULTS

In total, 12 studies were included. The review demonstrates a limited understanding of clinical oral health at the time of initial ventilation. Significant variation in both assessment methods and reporting of oral health makes comparison of results difficult resulting in a poor overall understanding of oral health at the time of intubation.

CONCLUSION

Standardized assessment and reporting methods may improve clinical application of findings and help direct future research. We suggest developing a core outcome set to ensure consistent use of assessment tools as well as standardized reporting of results.

RELEVANCE TO CLINICAL PRACTICE

It is essential that a good understanding of oral health at the time of initial ventilation is gained so that patients receive more targeted oral hygiene intervention in ICU, potentially leading to improved patient outcomes.

Prevalence of oral complications in the course of severe SARS-CoV-2 infection under mechanical non-invasive ventilation

BACKGROUND

The management of oral health during severe symptoms of Covid-19 is still a challenge, especially in intensive care units under invasive/noninvasive ventilation in hospital. Understanding the cause-and-effect relationships may allow for individual adjustment of oral care recommendations during Covid-19 disease. The study's objective was to assess Covid-19 patients' oral health status under hospital treatment due to pulmonary adverse Covid-19 outcomes.

MATERIAL AND METHODS

Covid-19 patients (mean age 74.4 ± 15.4; n = 120, male n = 50/female n = 70) were admitted to hospital in the acute phase of Covid-19 between January and March 2022 who required oxygen therapy due to pneumonia, rapid respiratory failure, low saturation. Blood and radiological tests were taken according to National Health Fund guidelines. The condition of teeth (Decayed, Missing, Filled teeth as DMFT index), dental hygiene (Plaque Control Record as PCR index), periodontal status (probing depth PD, clinical attachment CAL, bleeding on probing BOP) and oral mucosa (BRUSHED and Beck scores) were examined.

RESULTS

Charateristics of the teeth (dental caries 35.2%, DMFT Median 22), plaque retention (83.4%), advanced periodontitis (48.3%), xerostomia (74.2%), oral mucosa inflammation (80.8%), angular cheilitis (53.3%), hemorrhagic (21.7%) showed a high incidence of harmful oral conditions. BRUSHED model and Beck score indicated moderate oral dysfunction and need for oral care every 8 h. Spearman's analysis revealed a significant positive correlation between pneumonia and neutrophile, interleukin-6 IL-6, C-reactive protein CRP (p = 0.01, p < 0.001, p < 0.001), negative to lymphocyte count (p < 0.001). Multiple and logistic regressions selected the following risk predictors for pneumonia as IL-6, CRP, obesity and for severe COVID-19 symptoms D-dimer level and a lack of targeted vaccination (p < 0.001). Among oral predictors, the PCR index and Beck score were significant for both outcomes (respectively p < 0.001, p < 0.012). Patients who received oxygen therapy with face masks had more often angular heilitis and debris (p = 0.025, p = 0.035).

CONCLUSIONS

COVID-19 hospitalised patients with severe symptoms crossing with poor oral health-related conditions. This may exacerbate a response for COVID infection, and play a role in cytokine storm. For Covid-19 management, to inhibit extraoral/intraoral complications, it is recommended to adjust oral hygiene procedures, including antibacterial, protective, moisturising agents after individual oral health assessment.

Simultaneous Analysis of Bacterial and Fungal Communities in Oral Samples from Intubated Patients in Intensive Care Unit

Intubated patients in intensive care units (ICUs) too frequently contract ventilator-associated pneumonia or Candida infections. Oropharyngeal microbes are believed to play an important etiologic role. This study was undertaken to determine whether next-generation sequencing (NGS) can be used to simultaneously analyze bacterial and fungal communities. Buccal samples were collected from intubated ICU patients. Primers targeting the V1-V2 region of bacterial 16S rRNA and the internal transcribed spacer 2 (ITS2) region of fungal 18S rRNA were used. V1-V2, ITS2, or mixed V1-V2/ITS2 primers were used to prepare an NGS library. Bacterial and fungal relative abundances were comparable for V1-V2, ITS2, or mixed V1-V2/ITS2 primers, respectively. A standard microbial community was used to adjust the relative abundances to theoretical abundance, and NGS and RT-PCR-adjusted relative abundances showed a high correlation. Using mixed V1-V2/ITS2 primers, bacterial and fungal abundances were simultaneously determined. The constructed microbiome network revealed novel interkingdom and intrakingdom interactions, and the simultaneous detection of bacterial and fungal communities using mixed V1-V2/ITS2 primers enabled analysis across two kingdoms. This study provides a novel approach to simultaneously determining bacterial and fungal communities using mixed V1-V2/ITS2 primers.

Sodium Fluoride Exposure Leads to ATP Depletion and Altered RNA Decay in Escherichia coli under Anaerobic Conditions

Although fluoride-containing compounds are widely used to inhibit bacterial growth, the reprogramming of gene expression underlying cellular responses to fluoride, especially under anaerobic conditions, is still poorly understood. Here, we compare the genome-wide transcriptomic profiles of E. coli grown in the absence (control) or presence (20 and 70 mM) of sodium fluoride (NaF) under anaerobic conditions and assess the impact of fluoride-dependent ATP depletion on RNA turnover. Tiling array analysis revealed transcripts displaying altered abundance in response to NaF treatments. Quantile-based K-means clustering uncovered a subset of genes that were highly upregulated and then downregulated in response to increased and subsequently decreased fluoride concentrations, many of which (~40%) contained repetitive extragenic palindromic (REP) sequences. Northern blot analysis of some of these highly upregulated REP-containing transcripts (i.e., osmC, proP, efeO and yghA) confirmed their considerably enhanced abundance in response to NaF treatment. An mRNA stability analysis of osmC and yghA transcripts demonstrated that fluoride treatment slows down RNA degradation, thereby enhancing RNA stability and steady-state mRNA levels. Moreover, we demonstrate that turnover of these transcripts depends on RNase E activity and RNA degradosome. Thus, we show that NaF exerts significant effects at the whole-transcriptome level under hypoxic growth (i.e., mimicking the host environment), and fluoride can impact gene expression posttranscriptionally by slowing down ATP-dependent degradation of structured RNAs. IMPORTANCE Gram-negative Escherichia coli is a rod-shaped facultative anaerobic bacterium commonly found in microaerobic/anaerobic environments, including the dental plaques of warm-blooded organisms. These latter can be treated efficiently with fluoride-rich compounds that act as anticaries agents to prevent tooth decay. Although fluoride inhibits microbial growth by affecting metabolic pathways, the molecular mechanisms underlying its activity under anaerobic conditions remain poorly defined. Here, using genome-wide transcriptomics, we explore the impact of fluoride treatments on E. coli gene expression under anaerobic conditions. We reveal key gene clusters associated with cellular responses to fluoride and define its ATP-dependent stabilizing effects on transcripts containing repetitive extragenic palindromic sequences. We demonstrate the mechanisms controlling the RNA stability of these REP-containing mRNAs. Thus, fluoride can affect gene expression posttranscriptionally by stabilizing structured RNAs.

Impact of tooth brushing on oral bacteriota and health care-associated infections among ventilated COVID-19 patients: an intervention study

BACKGROUND

Up to 48% of ventilated coronavirus disease 2019 (COVID-19) patients develop ventilator-associated pneumonia (VAP) during hospitalization in an ICU. Dysbiotic oral microbiota can colonize the lower respiratory tract and lead to VAP. It is recommended to introduce oral care strategies in the ICU to prevent VAP. In this study, we observed the impact of an oral hygienic protocol with tooth brushing on cultivable oral bacteriota, the incidence of HAI and patient safety among mechanically ventilated COVID-19 patients in an ICU setting.

METHODS

In this prospective cohort study, we recruited 56 adult COVID-19 patients who qualified for mechanical ventilation. Patients were divided into 2 groups depending on the oral care procedure: standard and extended oral procedures with tooth brushing. Oral bacteriota samples were taken first within 36 h and after 7 days of intubation. Microorganisms were identified by MALDI/TOF mass spectrometry. bacterial health care-associated infection (HAI) cases were retrospectively analyzed by etiology. A PFGE study was performed for Klebsiella pneumoniae to check for clonal spreading of strains from oral bacteriota samples and HAI cases.

RESULTS

We observed significant dysbiosis and a decrease in cultivable oral bacteriota diversity, with a high frequency of potentially pathogenic species, including Acinetobacter baumannii and K. pneumoniae. The HAI incidence rate was high (55.2/1000 patient-days), most commonly of K. pneumoniae and A. baumannii etiologies, which correlated with the presence of A. baumannii and K. pneumoniae in the oral samples. Strains isolated from VAP cases were the same as oral isolates in 8 cases. The procedure with tooth brushing led to less frequent identification of A. baumannii in oral samples (55.6% vs. 5.3%, p = 0.001); however, it did not decrease the incidence of HAIs.

CONCLUSIONS

Dysbiotic oral bacteriota is an important source of respiratory pathogens. The introduction of tooth brushing in oral hygiene protocols in an ICU setting was effective in decreasing the extent of oral bacteriota dysbiosis; however, it did not reduce the risk of HAIs or mortality.

TRIAL REGISTRATION

1072.6120.333.2020.

Bioactivation of an orthodontic wire using multifunctional nanomaterials to prevent plaque accumulation

Controlling the growth of biofilm on orthodontic material has become a difficult challenge in modern dentistry. The antibacterial efficacy of currently used orthodontic material becomes limited due to the higher affinity of oral microbial flora for plaque formation on the material surface. Thus it is crutial to device an efficient strategy to prevent plaque buildup caused by pathogenic microbiota. In this work, we have fabricated a bioactive orthodontic wire using titanium nanoparticles (TiO₂NPs) and silver nanoparticles (AgNPs). AgNPs were synthesized from the extracts of Ocimum sanctum, Ocimum tenuiflorum, Solanum surattense, and Syzygium aromaticum, while the TiO₂NPs were synthesized by the Sol-Gel method. The nanoparticles were characterized by various biophysical techniques. The surface of the dental wire was molded by functionalizing these AgNPs followed by an additional coating of TiO₂NPs. Functionalized dental wires were found to counteract the formation of tenacious intraoral biofilm, and showed an enhanced anti-bacterial effect against Multi-Drug Resistant (MDR) bacteria isolated from patients with various dental ailments. Data revealed that such surface coating counteracts the bacterial pathogens by inducing the leakage of Ag ions which eventually disrupts the cell membrane as confirmed from TEM micrographs. The results offer a significant opportunity for innovations in developing nanoparticle-based formulations to modify or fabricate an effective orthodontic material.

Time-dependent microbial shifts during crayfish decomposition in freshwater and sediment under different environmental conditions

Fossilization processes and especially the role of bacterial activity during the preservation of organic material has not yet been well understood. Here, we report the results of controlled taphonomic experiments with crayfish in freshwater and sediment. 16S rRNA amplicon analyzes showed that the development of the bacterial community composition over time was correlated with different stages of decay and preservation. Three dominating genera, Aeromonas, Clostridium and Acetobacteroides were identified as the main drivers in the decomposition of crayfish in freshwater. Using micro-computed tomography (µ-CT), scanning electron microscopy (SEM) and confocal Raman spectroscopy (CRS), calcite clusters were detected after 3-4 days inside crayfish carcasses during their decomposition in freshwater at 24 °C. The precipitation of calcite clusters during the decomposition process was increased in the presence of the bacterial genus Proteocatella. Consequently, Proteocatella might be one of the bacterial genera responsible for fossilization.

Identifying oral disease variables associated with pneumonia emergence by application of machine learning to integrated medical and dental big data to inform eHealth approaches

Background

The objective of this study was to build models that define variables contributing to pneumonia risk by applying supervised Machine Learning-(ML) to medical and oral disease data to define key risk variables contributing to pneumonia emergence for any pneumonia/pneumonia subtypes.

Methods

Retrospective medical and dental data were retrieved from Marshfield Clinic Health System's data warehouse and integrated electronic medical-dental health records (iEHR). Retrieved data were pre-processed prior to conducting analyses and included matching of cases to controls by (a) race/ethnicity and (b) 1:1 Case: Control ratio. Variables with >30% missing data were excluded from analysis. Datasets were divided into four subsets: (1) All Pneumonia (all cases and controls); (2) community (CAP)/healthcare associated (HCAP) pneumonias; (3) ventilator-associated (VAP)/hospital-acquired (HAP) pneumonias and (4) aspiration pneumonia (AP). Performance of five algorithms were compared across the four subsets: Naïve Bayes, Logistic Regression, Support Vector Machine (SVM), Multi-Layer Perceptron (MLP) and Random Forests. Feature (input variables) selection and ten-fold cross validation was performed on all the datasets. An evaluation set (10%) was extracted from the subsets for further validation. Model performance was evaluated in terms of total accuracy, sensitivity, specificity, F-measure, Mathews-correlation-coefficient and area under receiver operating characteristic curve (AUC).

Results

In total, 6,034 records (cases and controls) met eligibility for inclusion in the main dataset. After feature selection, the variables retained in the subsets were: All Pneumonia (n = 29 variables), CAP-HCAP (n = 26 variables); VAP-HAP (n = 40 variables) and AP (n = 37 variables), respectively. Variables retained (n = 22) were common across all four pneumonia subsets. Of these, the number of missing teeth, periodontal status, periodontal pocket depth more than 5 mm and number of restored teeth contributed to all the subsets and were retained in the model. MLP outperformed other predictive models for All Pneumonia, CAP-HCAP and AP subsets, while SVM outperformed other models in VAP-HAP subset.

Conclusion

This study validates previously described associations between poor oral health and pneumonia. Benefits of an integrated medical-dental record and care delivery environment for modeling pneumonia risk are highlighted. Based on findings, risk score development could inform referrals and follow-up in integrated healthcare delivery environment and coordinated patient management.

Incidence of Postoperative Pneumonia and Oral Microbiome for Patients with Cancer Operation

Postoperative pneumonia is a serious problem for patients and medical staff. In Japan, many hospitals introduced perioperative oral care management for the efficient use of medical resources. However, a high percentage of postoperative pneumonia still developed. Therefore, there is a need to identify the specific respiratory pathogens to predict the incidence of pneumonia The purpose of this study was to find out the candidate of bacterial species for the postoperative pneumonia. This study applied case-control study design for the patients who had a cancer operation with or without postoperative pneumonia. A total of 10 patients undergoing a cancer operation under general anesthesia participated in this study. The day before a cancer operation, preoperative oral care management was applied. Using the next generation sequence, oral microbiome of these patients was analyzed at the time of their first visit, the day before and after a cancer operation. Porphyromonas gingivalis and Fusobacterium nucleatum group can be a high risk at first visit. Atopobium parvulum and Enterococcus faecalis before a cancer operation can be a high risk. Poor oral hygiene increased the risk of incidence of postoperative pneumonia. Increased periodontal pathogens can be a high risk of the incidence of postoperative pneumonia. In addition, increased intestinal bacteria after oral care management can also be a high risk for the incidence of postoperative pneumonia.

Occurrence of plasmid-mediated quinolone resistance genes in Pseudomonas aeruginosa strains isolated from clinical specimens in southwest Iran: a multicentral study

This study aimed to assess the presence of qnrA, qnrB, qnrC, qnrD, qnrS, qepA, and aac(6′)-Ib-cr determinants as well as quinolone resistance pattern of clinical isolates of P. aeruginosa in Ahvaz, southwest Iran. A total of 185 clinical isolates of P. aeruginosa were collected from 5 university-affiliated hospitals in Ahvaz, southwest Iran. The disk diffusion method was applied to assess the quinolone resistance pattern. The presence of qnrA, qnrB, qnrC, qnrD, qnrS, qepA, and aac(6′)-Ib-cr genes was investigated by the polymerase chain reaction (PCR) method. Overall, 120 (64.9%) isolates were non-susceptible to quinolones. The most and the less quinolone resistance rates were observed against ciprofloxacin (59.4%) and ofloxacin (45.9%), respectively. The prevalence rates of qnr genes were as follows: qnrA (25.8%), qnrB (29.2%), and qnrS (20.8%). The qnrB gene was the most common type of qnr genes. The qnr genes were occurred in 37.5% (n = 45/120) of quinolne-resistant isolates, simultaneously. The qnrC, qnrD, qepA, and aac(6′)-Ib-cr genes were not recognized in any isolates. In conclusion, the ofloxacin was the most effective quinolone. This study was the first to shed light on the prevalence of PMQR genes among P. aeruginosa isolates in southwest Iran.

Oral health care for the critically ill: a narrative review

Background

The link between oral bacteria and respiratory infections is well documented. Dental plaque has the potential to be colonized by respiratory pathogens and this, together with microaspiration of oral bacteria, can lead to pneumonia particularly in the elderly and critically ill. The provision of adequate oral care is therefore essential for the maintenance of good oral health and the prevention of respiratory complications.

Main body

Numerous oral care practices are utilised for intubated patients, with a clear lack of consensus on the best approach for oral care. This narrative review aims to explore the oral-lung connection and discuss in detail current oral care practices to identify shortcomings and offer suggestions for future research. The importance of adequate oral care has been recognised in guideline interventions for the prevention of pneumonia, but practices differ and controversy exists particularly regarding the use of chlorhexidine. The oral health assessment is also an important but often overlooked element of oral care that needs to be considered. Oral care plans should ideally be implemented on the basis of an individual oral health assessment. An oral health assessment prior to provision of oral care should identify patient needs and facilitate targeted oral care interventions.

Conclusion

Oral health is an important consideration in the management of the critically ill. Studies have suggested benefit in the reduction of respiratory complication such as Ventilator Associated Pneumonia associated with effective oral health care practices. However, at present there is no consensus as to the best way of providing optimal oral health care in the critically ill. Further research is needed to standardise oral health assessment and care practices to enable development of evidenced based personalised oral care for the critically ill.

Combination of toothbrushing and chlorhexidine compared with exclusive use of chlorhexidine to reduce the risk of ventilator-associated pneumonia: A systematic review with meta-analysis

This study aimed to compare the effectiveness of 0.12% chlorhexidine alone and 0.12% chlorhexidine in combination with toothbrushing to prevent ventilator-associated pneumonia (VAP) in mechanically ventilated patients. The Embase, Latin American and Caribbean Health Science Literature, PubMed, Scientific Electronic Library Online, Scopus, LIVIVO, Web of Science, Cochrane Library, OpenThesis, and Open Access Thesis and Dissertations databases were used. Only randomized controlled trials without restrictions on the year or language of publication were included. Two reviewers assessed the risk of bias using the Joanna Briggs Institute Critical Appraisal Tool. A meta-analysis using a random-effects model estimated the combined relative risk (RR). The Grading of Recommendations, Assessment, Development and Evaluations approach was used to assess the certainty of the evidence. Initially, 2,337 studies were identified, of which 4 were considered in the systematic review and 3 in the meta-analysis (total sample: 796 patients). The studies were published between 2009 and 2017. All eligible studies had a low risk of bias. The meta-analysis revealed that the risk of VAP was 24% lower in patients receiving chlorhexidine combined with toothbrushing than in those receiving chlorhexidine alone (RR: 0.76; 95% confidence interval: 0.55-1.06), with moderate certainty of evidence and without statistical significance. In conclusion, considering the limitations of this study, a standard protocol for the prevention of VAP is not yet recommended. More studies with larger sample sizes are needed to draw strong conclusions. However, considering that toothbrushing is a simple intervention, it should be a common practice in mechanically ventilated patients, especially among patients with coronavirus disease.

Oral hygiene care for critically ill patients to prevent ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is defined as pneumonia developing in people who have received mechanical ventilation for at least 48 hours. VAP is a potentially serious complication in these patients who are already critically ill. Oral hygiene care (OHC), using either a mouthrinse, gel, swab, toothbrush, or combination, together with suction of secretions, may reduce the risk of VAP in these patients.

OBJECTIVES

To assess the effects of oral hygiene care (OHC) on incidence of ventilator-associated pneumonia in critically ill patients receiving mechanical ventilation in hospital intensive care units (ICUs).

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 February 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2020, Issue 1), MEDLINE Ovid (1946 to 25 February 2020), Embase Ovid (1980 to 25 February 2020), LILACS BIREME Virtual Health Library (1982 to 25 February 2020) and CINAHL EBSCO (1937 to 25 February 2020). We also searched the VIP Database (January 2012 to 8 March 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effects of OHC (mouthrinse, gel, swab, toothbrush or combination) in critically ill patients receiving mechanical ventilation for at least 48 hours.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed search results, extracted data and assessed risk of bias in included studies. We contacted study authors for additional information. We reported risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, using the random-effects model of meta-analysis when data from four or more trials were combined.

MAIN RESULTS

We included 40 RCTs (5675 participants), which were conducted in various countries including China, USA, Brazil and Iran. We categorised these RCTs into five main comparisons: chlorhexidine (CHX) mouthrinse or gel versus placebo/usual care; CHX mouthrinse versus other oral care agents; toothbrushing (± antiseptics) versus no toothbrushing (± antiseptics); powered versus manual toothbrushing; and comparisons of other oral care agents used in OHC (other oral care agents versus placebo/usual care, or head-to-head comparisons between other oral care agents). We assessed the overall risk of bias as high in 31 trials and low in two, with the rest being unclear. Moderate-certainty evidence from 13 RCTs (1206 participants, 92% adults) shows that CHX mouthrinse or gel, as part of OHC, probably reduces the incidence of VAP compared to placebo or usual care from 26% to about 18% (RR 0.67, 95% confidence intervals (CI) 0.47 to 0.97; P = 0.03; I2 = 66%). This is equivalent to a number needed to treat for an additional beneficial outcome (NNTB) of 12 (95% CI 7 to 128), i.e. providing OHC including CHX for 12 ventilated patients in intensive care would prevent one patient developing VAP. There was no evidence of a difference between interventions for the outcomes of mortality (RR 1.03, 95% CI 0.80 to 1.33; P = 0.86, I2 = 0%; 9 RCTs, 944 participants; moderate-certainty evidence), duration of mechanical ventilation (MD -1.10 days, 95% CI -3.20 to 1.00 days; P = 0.30, I2 = 74%; 4 RCTs, 594 participants; very low-certainty evidence) or duration of intensive care unit (ICU) stay (MD -0.89 days, 95% CI -3.59 to 1.82 days; P = 0.52, I2 = 69%; 5 RCTs, 627 participants; low-certainty evidence). Most studies did not mention adverse effects. One study reported adverse effects, which were mild, with similar frequency in CHX and control groups and one study reported there were no adverse effects. Toothbrushing (± antiseptics) may reduce the incidence of VAP (RR 0.61, 95% CI 0.41 to 0.91; P = 0.01, I2 = 40%; 5 RCTs, 910 participants; low-certainty evidence) compared to OHC without toothbrushing (± antiseptics). There is also some evidence that toothbrushing may reduce the duration of ICU stay (MD -1.89 days, 95% CI -3.52 to -0.27 days; P = 0.02, I2 = 0%; 3 RCTs, 749 participants), but this is very low certainty. Low-certainty evidence did not show a reduction in mortality (RR 0.84, 95% CI 0.67 to 1.05; P = 0.12, I2 = 0%; 5 RCTs, 910 participants) or duration of mechanical ventilation (MD -0.43, 95% CI -1.17 to 0.30; P = 0.25, I2 = 46%; 4 RCTs, 810 participants).

AUTHORS' CONCLUSIONS

Chlorhexidine mouthwash or gel, as part of OHC, probably reduces the incidence of developing ventilator-associated pneumonia (VAP) in critically ill patients from 26% to about 18%, when compared to placebo or usual care. We did not find a difference in mortality, duration of mechanical ventilation or duration of stay in the intensive care unit, although the evidence was low certainty. OHC including both antiseptics and toothbrushing may be more effective than OHC with antiseptics alone to reduce the incidence of VAP and the length of ICU stay, but, again, the evidence is low certainty. There is insufficient evidence to determine whether any of the interventions evaluated in the studies are associated with adverse effects.

Preventing Ventilator-Associated Pneumonia in Intensive Care Unit by improved Oral Care: a Review of Randomized Control Trials

To assess the effects of various oral care methods on the incidence of VAP in patients receiving mechanical ventilation in intensive care units, an exhaustive literature search was undertaken using MEDLINE as well as a manual review of the relevant literature and citations. Eight publications were selected for this review. The primary endpoint was the incidence of VAP. Different oral care methods for preventing VAP were the subject of this review. Two studies that were reviewed in this article showed significant statistical difference between the intervention group and the control group regarding different oral care for lowering the incidence of VAP. The rest of the studies showed no significant statistical difference between the intervention group and the control group, but showed the importance of meticulous oral hygiene in those patients. Mechanically ventilated patients who suffer from poor oral hygiene are exposed to the harmful accumulation of oral plaque and the initiation of VAP. Proper oral care by qualified care givers can reduce the incidence of VAP. Proper oral care needs to be considered part of the medical treatment plan when a patient is admitted to the ICU to lower the incidence rates of VAP. Oral care treatment of ventilated patients in the intensive care units, for prevention of ventilator-associated pneumonia, is with high clinical relevance, decreasing morbidity and mortality in the ICU. We recommend that ICU medical teams will plan a protocol of oral care treatment, based on our article results, and implement it as part of the daily routine.

Non-ventilator health care-associated pneumonia (NV-HAP): Pathogenesis and microbiology of NV-HAP

Studies demonstrate that those at risk for developing nonventilator associated pneumonia (NV-HAP) include the very young and the very old, as well as persons with compromised immune systems cardiovascular and/or pulmonary disease. This section includes a review of the pathogenesis and microbiology of NV-HAP, including bacterial as well as viral and fungal pathogens. Etiology, modes of transmission, and specific prevention strategies associated with various causative microorganisms are highlighted.

Biogeography of the Oral Microbiome: The Site-Specialist Hypothesis

Microbial communities are complex and dynamic, composed of hundreds of taxa interacting across multiple spatial scales. Advances in sequencing and imaging technology have led to great strides in understanding both the composition and the spatial organization of these complex communities. In the human mouth, sequencing results indicate that distinct sites host microbial communities that not only are distinguishable but to a meaningful degree are composed of entirely different microbes. Imaging suggests that the spatial organization of these communities is also distinct. Together, the literature supports the idea that most oral microbes are site specialists. A clear understanding of microbiota structure at different sites in the mouth enables mechanistic studies, informs the generation of hypotheses, and strengthens the position of oral microbiology as a model system for microbial ecology in general.

Biofilm and methods of its eradication

Microorganisms occur in the natural environment in the form of planktonic or create biofilms, i.e. communities of cells surrounded by the extracellular matrix. This is possible due to the phenomenon of quorum sensing, i.e. the ability of microorganisms to estimate their own density and change the expression of genes in response to them. Within such a structure, microorganisms are protected against harmful environmental conditions, their metabolic profile and the level of expression of individual genes are also changed, which leads to an increase in the pathogenicity of organisms associated in the form of biofilms. They pose a huge threat to hospital patients because they are capable of residing abiotic surfaces, such as catheters and endoprostheses, and can cause infection. The current methods of combating microbes with antibiotics and fungicides lose their effectiveness, both due to the increasing drug resistance of clinically relevant strains, but also to the very properties of biofilms. This determines the need to search for new and effective methods (physical, chemical and biological) to eradicate biofilms

Oral microbiomes in children with asthma and dental caries

OBJECTIVE

Recently, a significant association between dental caries and the severity of bronchial asthma in children has been revealed. This finding indicates a possible relationship between the oral microbiome and the pathogenesis of asthma. The purpose of our study was to estimate differences in the dental plaque microbiota of asthmatic children with and without dental caries by 16S rDNA sequencing.

MATERIAL AND METHODS

Dental plaque samples were obtained with a spoon excavator from the occlusal surface of one deciduous tooth (the second mandibular left molar in caries-free children and the most affected tooth in caries-affected children). Total DNA was extracted from dental plaque. DNA libraries were analysed by 16S rRNA gene sequencing on the MiSeq (Illumina) platform.

RESULTS

There were no significant differences in the composition of bacterial communities from both caries-affected and caries-free children with asthma. The "caries-enriched" genus was Veillonella (Veillonellaceae, Selenomonadales, Negativicutes). Relative abundance of Neisseria was significantly higher in caries-free children with asthma (p < 0.05).

CONCLUSIONS

The most significant difference in compared bacterial communities was a higher relative abundance of Veillonella in caries-affected plaques that suggests its involvement in pathogenesis of caries. Potential respiratory pathogens are present in oral cavity of both caries-affected and caries-free asthmatic children.

Bacterial-Host Interactions: Physiology and Pathophysiology of Respiratory Infection

It has long been thought that respiratory infections are the direct result of acquisition of pathogenic viruses or bacteria, followed by their overgrowth, dissemination, and in some instances tissue invasion. In the last decades, it has become apparent that in contrast to this classical view, the majority of microorganisms associated with respiratory infections and inflammation are actually common members of the respiratory ecosystem and only in rare circumstances do they cause disease. This suggests that a complex interplay between host, environment, and properties of colonizing microorganisms together determines disease development and its severity. To understand the pathophysiological processes that underlie respiratory infectious diseases, it is therefore necessary to understand the host-bacterial interactions occurring at mucosal surfaces, along with the microbes inhabiting them, during symbiosis. Current knowledge regarding host-bacterial interactions during asymptomatic colonization will be discussed, including a plausible role for the human microbiome in maintaining a healthy state. With this as a starting point, we will discuss possible disruptive factors contributing to dysbiosis, which is likely to be a key trigger for pathobionts in the development and pathophysiology of respiratory diseases. Finally, from this renewed perspective, we will reflect on current and potential new approaches for treatment in the future.

Clinical validation and assessment of a modular fluorescent imaging system and algorithm for rapid detection and quantification of dental plaque

Background

Significant numbers of adults and children have untreated plaque due to poor oral hygiene and consequently suffer from associate dental and systemic diseases.

Methods

A handheld device equipped with 405 nm light-emitting diodes was constructed to examine the prevalence of red fluorescence signatures associated with dental plaque. This device was used for in vivo imaging of all four incisors and all four canines of twenty-eight consenting human subjects. The same areas were further imaged under white light illumination with a commercial image-processing based plaque-imaging device, and evaluated by a hygienist and dentist. A custom computer vision algorithm using pixel information was developed to calculate plaque coverage ratios ranging from 0 (no plaque) to 1 (complete plaque coverage) for images captured by both devices.

Results

The algorithm calculated red fluorescence-based plaque coverage ratios ranging from 0.011 to 0.211 for the subjects imaged. Clinical assessment and statistical analyses of associated plaque ratios of the 405 nm device images indicated high sensitivity and specificity in detecting dental plaque by the experimental device compared to the commercial reference device.

Conclusions

The low-cost and open source 405 nm device and the associated computer vision algorithm successfully captured red fluorescence signatures associated with dental plaque and demonstrated comparable performance to a commercially available device. Therefore, a proof of concept validation was provided for the construction and application of a sensitive cost-effective plaque-detecting device. A miniaturized mobile adaptable version of the device was also provided, together with and a step-by-step guide for device assembly and webhost the associated software, to facilitate open-source access to a cost-effective at-home, in-clinic oral care technology.

Trial registration

ClinicalTrials.gov NCT03379337, December 19 2017. Retrospectively registered.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12903-017-0472-4) contains supplementary material, which is available to authorized users.

Association between oral health and upper respiratory tract infection among children

BACKGROUND

The oral cavity is a potential reservoir for respiratory pathogens. This longitudinal study investigated the association between upper respiratory tract infection (URI) and oral health among children.

METHODS

A total of 288 children aged 4 years were recruited. Their dental caries and oral hygiene status were clinically determined, using the dmft (decayed, missing and filled teeth) index and the Silness-Löe plaque index. Questionnaires were completed by parents to collect information on the child's socio-demographic background and URI episodes and symptoms in the following 12 months. Standard or zero-inflated negative binomial regressions were used to analyse the association between URI and both oral health indicators (dmft and plaque score).

RESULTS

Some 138 (47.9%) children had URI in 12 months, including 63 (21.9%) and 75 (26.0%) children with 1-2 episodes and ≥3 episodes, respectively. The reported URI episodes fell into two peaks, coinciding with the two influenza peaks in Hong Kong. Significantly a higher dmft was found among children without URI compared with children who had ≥3 URI episodes (1.32 vs. 0.49; P = 0.043). The number of URI episodes was inversely associated with dmft (IRR = 0.851; 95% CI: 0.766-0.945; P = 0.003). There was no significant association between the plaque score and URI (P > 0.05).

CONCLUSIONS

The children's caries experience was associated with reduced episodes of URI. Whether this inverse association is attributed to the immune response induced by dental caries is yet to be investigated.

Community analysis of dental plaque and endotracheal tube biofilms from mechanically ventilated patients

PURPOSE

Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations.

MATERIAL AND METHODS

Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed.

RESULTS

No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance.

CONCLUSION

The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group.

Respiratory pathogen colonization of dental plaque, the lower airways, and endotracheal tube biofilms during mechanical ventilation

PURPOSE

In mechanically ventilated patients, the endotracheal tube is an essential interface between the patient and ventilator, but inadvertently, it also facilitates the development of ventilator-associated pneumonia (VAP) by subverting pulmonary host defenses. A number of investigations suggest that bacteria colonizing the oral cavity may be important in the etiology of VAP. The present study evaluated microbial changes that occurred in dental plaque and lower airways of 107 critically ill mechanically ventilated patients.

MATERIALS AND METHODS

Dental plaque and lower airways fluid was collected during the course of mechanical ventilation, with additional samples of dental plaque obtained during the entirety of patients' hospital stay.

RESULTS

A "microbial shift" occurred in dental plaque, with colonization by potential VAP pathogens, namely, Staphylococcus aureus and Pseudomonas aeruginosa in 35 patients. Post-extubation analyses revealed that 70% and 55% of patients whose dental plaque included S aureus and P aeruginosa, respectively, reverted back to having a predominantly normal oral microbiota. Respiratory pathogens were also isolated from the lower airways and within the endotracheal tube biofilms.

CONCLUSIONS

To the best of our knowledge, this is the largest study to date exploring oral microbial changes during both mechanical ventilation and after recovery from critical illness. Based on these findings, it was apparent that during mechanical ventilation, dental plaque represents a source of potential VAP pathogens.