Opportunistic respiratory pathogens in the oral cavity of the elderly

Association between removable prosthesis-wearing and pneumonia: a systematic review and meta-analysis

BACKGROUND

A high burden of respiratory pathogens colonizing removable prosthesis surfaces suggests the potential of association between removable prosthesis-wearing and respiratory infections. Therefore, this systematic review and meta-analysis aimed to evaluate the evidence from clinical studies concerning the association between removable prosthesis-wearing and respiratory infections.

METHODS

Clinical studies that reported respiratory infections associated with adult patients wearing removable prostheses in any centers (hospitals and nursing homes) or communities were included. Literature was searched across five electronic databases (MEDLINE, Cochrane Library, EMBASE, Web of Science, and Scopus) to 28 May 2024. An additional search was performed for unpublished trials and references cited in related studies. The Newcastle-Ottawa Scale was employed for the quality assessment. The certainty assessment was established using GRADE. The results were pooled using a frequentist random-effects meta-analysis and the odds ratios generated.

RESULTS

A total of 1143 articles were identified. Thirteen articles had full-text articles screening and an additional two articles were added through reference linkage. Ultimately, six non-randomized clinical studies reporting various types of pneumonia contributed to this review. Overall odds of having pneumonia among prosthesis wearers were 1.43 (95% CI: 0.76 to 2.69) and 1.27 (95% CI: 1.11 to 1.46) using the random- and fixed-effects models, respectively. The heterogeneity in the meta-analysis was substantial. In subgroup analysis according to the study design, the heterogeneity within prospective studies was much reduced, I2 = 0% (p = 0.355). The certainty of the evidence evaluated using the GRADE approach was low to very low evidence for prosthesis wearers developing pneumonia based on studies.

CONCLUSIONS

There was no conclusive evidence from the non-randomized clinical studies supporting whether prosthesis-wearing is a risk factor for pneumonia based on outcomes from this review.

Prevalence of respiratory pathogens colonizing on removable dental prostheses in healthy older adults: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to investigate the prevalence of opportunistic respiratory pathogens colonizing removable dental prostheses in older adults without respiratory diseases.

METHODS

This review was registered with PROSPERO and conducted in accordance with the principles formed by the working group of the Joanna Briggs Institute (JBI) to evaluate systematic reviews of prevalence data. Literature searches were conducted across five electronic databases. Quality assessments were determined according to a revised JBI critical appraisal checklist across nine criteria. Comparison between fixed- and random-effects meta-analyses were performed for sensitivity analysis. Prediction intervals were also presented when three or more studies were included in the meta-analysis.

RESULTS

Across the databases, 1091 articles were identified, and 591 articles remained after the removal of duplicates. Twenty "potentially effective" studies were identified. Ultimately eight studies informed this review and meta-analyses were performed for 13 known respiratory pathogens. The meta-analyses identified the top three common respiratory pathogens residing on the removable prostheses were, in descending order: Staphylococcus aureus: 31.81% (95% CI: 13.34%-48.24%); Staphylococcus epidermidis: 14.07% (95% CI: 7.88%-21.48%); Klebsiella pneumoniae: 10.50% (95% CI: 2.55%-22.30%). The heterogeneity scores for nine respiratory pathogen analyses were classified as "unimportant inconsistency", I2 = 0% (p > 0.1). For sensitivity analysis, there was no difference between the random- and fixed-effects models.

CONCLUSION

The existing evidence demonstrated a high burden of certain opportunistic respiratory pathogens, which may be considered a major potential cause of respiratory infections in older adults wearing removable prostheses.

A comparison of the prevalence of respiratory pathogens and opportunistic respiratory pathogenic profile of 'clean' and 'unclean' removable dental prostheses

OBJECTIVES

To determine and compare the opportunistic respiratory pathogenic index (ORPI) and prevalence of respiratory pathogens between clean and unclean removable prostheses.

METHODS

A cross-sectional study was conducted among 97 removable prosthesis wearers at a teaching dental hospital. Participants' prosthesis hygiene was grouped into clean and unclean. After prosthesis plaque samples were sequenced using the Type IIB Restriction-site Associated DNA Sequencing for Microbiome method, the prevalence was assessed for the presence of respiratory pathogens on each sample. The ORPIs for clean and unclean prostheses were quantified based on the sum of the relative abundance of respiratory pathogenic bacteria in a microbiome using a reference database that contains opportunistic respiratory pathogens and disease-associated information.

RESULTS

A total of 30 opportunistic respiratory pathogens were identified on the removable prostheses. Eighty-one (83.5 %) removable prostheses harboured respiratory pathogenic bacteria. Stenotrophomonas maltophilia (34.0 %), Pseudomonas aeruginosa (27.8 %), and Streptococcus agalactiae (27.8 %) were the top three prevalent respiratory pathogens detected in plaque samples. There was a significantly higher prevalence of respiratory pathogens residing on unclean than clean prostheses (P = 0.046). However, the ORPIs in both groups showed no statistically significant difference (P = 0.516).

CONCLUSIONS

The ORPIs for both clean and unclean prostheses demonstrated a similar abundance of respiratory pathogens. However, the high prevalence of respiratory pathogens residing on unclean prostheses should not be underestimated. Therefore, maintaining good prosthesis hygiene is still important for overall oral and systemic health, even though the direct link between prosthesis cleanliness and reduced abundance of respiratory pathogens has not been established.

CLINICAL SIGNIFICANCE

The association between the prevalence of respiratory pathogens and unclean removable prostheses has been demonstrated and might increase the theoretical risk of respiratory disease development.

Acinetobacter baumannii as an oro-dental pathogen: a red alert!!

OBJECTIVES

This review highlights the existence and association of Acinetobacter baumannii with the oro-dental diseases, transforming this systemic pathogen into an oral pathogen. The review also hypothesizes possible reasons for the categorization of this pathogen as code blue due to its stealthy entry into the oral cavity.

METHODOLOGY

Study data were retrieved from various search engines reporting specifically on the association of A. baumannii in dental diseases and tray set-ups. Articles were also examined regarding obtained outcomes on A. baumannii biofilm formation, iron acquisitions, magnitude of antimicrobial resistance, and its role in the oral cancers.

RESULTS

A. baumannii is associated with the oro-dental diseases and various virulence factors attribute for the establishment and progression of oro-mucosal infections. Its presence in the oral cavity is frequent in oral microbiomes, conditions of impaired host immunity, age related illnesses, and hospitalized individuals. Many sources also contribute for its prevalence in the dental health care environment and the presence of drug resistant traits is also observed. Its association with oral cancers and oral squamous cell carcinoma is also evident.

CONCLUSIONS

The review calls for awareness on the emergence of A. baumannii in dental clinics and for the need for educational programs to monitor and control the sudden outbreaks of such virulent and resistant traits in the dental health care settings.

Nasopharyngeal metatranscriptomics reveals host-pathogen signatures of pediatric sinusitis

Acute sinusitis (AS) is the fifth leading cause of antibiotic prescriptions in children. Distinguishing bacterial AS from common viral upper respiratory infections in children is crucial to prevent unnecessary antibiotic use but is challenging with current diagnostic methods. Despite its speed and cost, untargeted RNA sequencing of clinical samples from children with suspected AS has the potential to overcome several limitations of other methods. However, the utility of sequencing-based approaches in analysis of AS has not been fully explored. Here, we performed RNA-seq of nasopharyngeal samples from 221 children with clinically diagnosed AS to characterize their pathogen and host-response profiles. Results from RNA-seq were compared with those obtained using culture for three common bacterial pathogens and qRT-PCR for 12 respiratory viruses. Metatranscriptomic pathogen detection showed high concordance with culture or qRT-PCR, showing 87%/81% sensitivity (sens) / specificity (spec) for detecting bacteria, and 86%/92% (sens/spec) for viruses, respectively. We also detected an additional 22 pathogens not tested for in the clinical panel, and identified plausible pathogens in 11/19 (58%) of cases where no organism was detected by culture or qRT-PCR. We assembled genomes of 205 viruses across the samples including novel strains of coronaviruses, respiratory syncytial virus (RSV), and enterovirus D68. By analyzing host gene expression, we identified host-response signatures that distinguished bacterial and viral infections and correlated with pathogen abundance. Ultimately, our study demonstrates the potential of untargeted metatranscriptomics for in depth analysis of the etiology of AS, comprehensive host-response profiling, and using these together to work towards optimized patient care.

Bacteria in the oral cavity of individuals consuming intoxicating substances

Food habits and oral hygiene are critical attributes for physiochemical environment of the oral cavity. Consumption of intoxicating substances such as betel nut ('Tamul'), alcohol, smoking and chewing tobacco may strongly influence the oral ecosystem including commensal microbes. Therefore, a comparative assessment of microbes in the oral cavity between individuals consuming intoxicating substances and non-consumers may indicate the influence of these substances. Oral swabs were collected from consumers of intoxicating substances and non- consumers of Assam, India, microbes were isolated by culturing on Nutrient agar and identified by phylogenetic analysis of their 16S rRNA gene sequences. The risks of consumption of intoxicating substance on occurrence of microbes and health conditions were estimated using binary logistic regression. Mostly pathogens and opportunistic pathogens were found in the oral cavity of consumers and oral cancer patients which included Pseudomonas aeruginosa, Serratia marcescens, Rhodococcus antrifimi, Paenibacillus dendritiformis, Bacillus cereus, Staphylococcus carnosus, Klebsiella michiganensis and Pseudomonas cedrina. Enterobacter hormaechei was found in the oral cavity of cancer patients but not in other cases. Pseudomonas sp. were found to be widely distributed. The risk of occurrence of these organisms were found in between 0.01 and 2.963 odds and health conditions between 0.088 and 10.148 odds on exposure to different intoxicating substances. When exposed to microbes, the risk of varying health conditions ranged between 0.108 and 2.306 odds. Chewing tobacco showed a higher risk for oral cancer (10.148 odds). Prolonged exposure to intoxicating substances conduce a favorable environment for the pathogens and opportunistic pathogens to colonize in the oral cavity of individuals consuming intoxicating substances.

Positive feedback loop between dietary nitrate intake and oral health

Nitrate was once thought to be an inert end-product of endothelial-derived nitric oxide (NO) heme oxidation; however, this view has been radically revised over the past few decades. Following the clarification of the nitrate-nitrite-NO pathway, accumulated evidence has shown that nitrate derived from the diet is a supplementary source of endogenous NO generation, playing important roles in a variety of pathological and physiological conditions. However, the beneficial effects of nitrate are closely related with oral health, and oral dysfunction has an adverse effect on nitrate metabolism and further impacts overall systemic health. Moreover, an interesting positive feedback loop has been identified between dietary nitrate intake and oral health. Dietary nitrate's beneficial effect on oral health may further improve its bioavailability and promote overall systemic well-being. This review aims to provide a detailed description of the functions of dietary nitrate, with an emphasis on the key role oral health plays in nitrate bioavailability. This review also provides recommendations for a new paradigm that includes nitrate therapy in the treatment of oral diseases.

Candidiasis and Other Bacterial Infections among Patients Diagnosed with Burning Mouth Syndrome

Background and Objectives: Burning mouth syndrome (BMS) is a state in which a patient experiences intraoral burning or a dysesthetic sensation without clinically evident causative lesions in the oropharyngeal area. The disorder is linked to a variety of conditions, including dry mouth, Candida, and bacterial infections. The aim of this study was to determine the incidence of oral Candida and/or bacterial infections among patients with BMS and whether they have an effect on pain/burning and salivary flow levels. Objectives: (1) Gather patient data regarding the presence of oral infections, dry mouth, and pain levels in the morning, afternoon, and evening periods; (2) data analysis and assessment to determine medians, means, frequencies, correlations, and statistically significant differences between patient groups. Materials and Methods: Overall, 173 patients (23 males and 150 females) with BMS and 13 controls (five males and eight females) took part in the study. We measured pain/burning levels, unstimulated and stimulated salivary flow, the percentage of patients infected with Candida species and/or bacterial species, and the said species growth in Petri dishes. Results: Candida albicans was the most commonly found infection among patients with BMS (n = 28, 16.2%). Overall, 21.4% patients with BMS were diagnosed with either C. albicans or another Candida species. Enterobacter had the richest growth among patients with BMS (7.5% out of the infected 10.4% BMS patients). No statistical significance could be noted between the existence of either Candida species or bacterial species infections and changes in pain/burning and salivary flow levels. Negative correlations were noted between age and unstimulated and stimulated salivary flow, and positive correlations were noted between age and Candida andspecific bacteria species’ growth levels. Conclusions: Although patients with present bacterial or Candida infections showed a marginal increase in pain/burning levels, no direct statistically significant associations could be made between the presence of Candida species or other bacteria and the symptoms among patients with BMS.

The Impact of Human Microbiotas in Hematopoietic Stem Cell and Organ Transplantation

The human microbiota heavily influences most vital aspects of human physiology including organ transplantation outcomes and transplant rejection risk. A variety of organ transplantation scenarios such as lung and heart transplantation as well as hematopoietic stem cell transplantation is heavily influenced by the human microbiotas. The human microbiota refers to a rich, diverse, and complex ecosystem of bacteria, fungi, archaea, helminths, protozoans, parasites, and viruses. Research accumulating over the past decade has established the existence of complex cross-species, cross-kingdom interactions between the residents of the various human microbiotas and the human body. Since the gut microbiota is the densest, most popular, and most studied human microbiota, the impact of other human microbiotas such as the oral, lung, urinary, and genital microbiotas is often overshadowed. However, these microbiotas also provide critical and unique insights pertaining to transplantation success, rejection risk, and overall host health, across multiple different transplantation scenarios. Organ transplantation as well as the pre-, peri-, and post-transplant pharmacological regimens patients undergo is known to adversely impact the microbiotas, thereby increasing the risk of adverse patient outcomes. Over the past decade, holistic approaches to post-transplant patient care such as the administration of clinical and dietary interventions aiming at restoring deranged microbiota community structures have been gaining momentum. Examples of these include prebiotic and probiotic administration, fecal microbial transplantation, and bacteriophage-mediated multidrug-resistant bacterial decolonization. This review will discuss these perspectives and explore the role of different human microbiotas in the context of various transplantation scenarios.

Relationships Between Oral Microecosystem and Respiratory Diseases

Oral microecosystem is a very complicated ecosystem that is located in the mouth and comprises oral microbiome, diverse anatomic structures of oral cavity, saliva and interactions between oral microbiota and between oral microbiota and the host. More and more evidence from studies of epidemiology, microbiology and molecular biology is establishing a significant link between oral microecosystem and respiratory diseases. Microbiota settling down in oral microecosystem is known as the main source of lung microbiome and has been associated with the occurrence and development of respiratory diseases like pneumonia, chronic obstructive pulmonary disease, lung cancer, cystic fibrosis lung disease and asthma. In fact, it is not only indigenous oral microbes promote or directly cause respiratory infection and inflammation when inhaled into the lower respiratory tract, but also internal environment of oral microecosystem serves as a reservoir for opportunistic respiratory pathogens. Moreover, poor oral health and oral diseases caused by oral microecological dysbiosis (especially periodontal disease) are related with risk of multiple respiratory diseases. Here, we review the research status on the respiratory diseases related with oral microecosystem. Potential mechanisms on how respiratory pathogens colonize oral microecosystem and the role of indigenous oral microbes in pathogenesis of respiratory diseases are also summarized and analyzed. Given the importance of oral plaque control and oral health interventions in controlling or preventing respiratory infection and diseases, we also summarize the oral health management measures and attentions, not only for populations susceptible to respiratory infection like the elderly and hospitalized patients, but also for dentist or oral hygienists who undertake oral health care. In conclusion, the relationship between respiratory diseases and oral microecosystem has been established and supported by growing body of literature. However, etiological evidence on the role of oral microecosystem in the development of respiratory diseases is still insufficient. Further detailed studies focusing on specific mechanisms on how oral microecosystem participate in the pathogenesis of respiratory diseases could be helpful to prevent and treat respiratory diseases.

Volatiles Composition and Antimicrobial Activities of Areca Nut Extracts Obtained by Simultaneous Distillation-Extraction and Headspace Solid-Phase Microextraction

The volatile components of areca nuts were isolated by headspace solid-phase microextraction (HS-SPME, DVB/CAR/PDMS fiber extraction) and simultaneous hydrodistillation-extraction (SHDE) and analyzed by gas chromatography/mass spectrometry. Furthermore, all SHDE fractions were tested for antimicrobial activity using the disk diffusion method on nine Gram-negative and Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus canis, Streptococcus pyogenes, and Candida albicans). In total, 98 compounds (mainly alcohols, carbonyl compounds, fatty acids, esters, terpenes, terpenoids, and aliphatic hydrocarbons) were identified in SHDE fractions and by using SPME extraction Fatty acids were the main group of volatile constituents detected in all types of extracts. The microorganism most sensitive to the extract of the areca nut was Streptococcus canis. The results can provide essential information for the application of different treatments of areca nuts in the canning industry or as natural antibiotics.

Inorganic nitrate: A potential prebiotic for oral microbiota dysbiosis associated with type 2 diabetes

Oral microbiota dysbiosis, concomitant with decreased abundance of nitrate (NO₃^-)-reducing bacteria, oral net nitrite (NO₂^-) production, and reduced nitric oxide (·NO) bioactivity, is associated with the development of cardiometabolic disorders. Therefore, restoring the oral microbiome to a health-associated state is suggested as a therapeutic approach to potentiate the NO₃^--NO₂^--·NO pathway and provide a backup resource for insufficient NO production in conditions including cardiovascular disease and type 2 diabetes mellitus (T2DM). The current review discusses how inorganic NO₃^- can improve the oral microbial community in patients with T2DM and act as a prebiotic. Both animal and human experiments indicated that inorganic NO₃^- modulates the oral microbiome by increasing the abundance of health-associated NO₃^--reducing bacteria (e.g., Neisseria and Rothia) and decreasing the plenty of species Prevotella and Veillonella, leading to oral NO₂^- accumulation and improved systemic ·NO availability. Supplementation with NO₃^- reduces caries- and periodontitis-associated bacteria and the pathogenic genus related to insulin resistance and glucose intolerance. In addition, inorganic NO₃^- may provide a more optimal environment for NO₃^- reductase activity in the oral cavity, as it increases salivary flow rate and prevents decreased pH by inhibiting acid-producing bacteria.

Pathogenic oral bacteria in hospitalised patients with dysphagia: The silent epidemic

Background

Aspiration pneumonia is a serious and fatal complication of dysphagia, secondary to the ingestion of bacteria-laden secretions. However, no studies have documented the oral hygiene features present in patients who present with dysphagia.

Objectives

The purpose of this study was to describe the oral hygiene problems of adults admitted to a sub-acute rehabilitation hospital and who presented with dysphagia.

Methods

A descriptive, cross-sectional survey was conducted, during which 40 participants – 57.5% (n = 23) male and 42.5% (n = 17) female – underwent a clinical swallow evaluation using the Mann Assessment of Swallowing Ability (MASA) augmented with cervical auscultation (CA) and pulse oximetry (PO), an oral hygiene assessment using an adapted version of the Oral Health Assessment Tool (OHAT), followed by microbiology laboratory analysis of buccal swab samples to detect bacteria not considered part of the normal oral flora.

Results

Results indicated that poor oral hygiene status was a common feature amongst all participants who presented with dysphagia. The most prevalent oral hygiene issues were related to abnormalities concerning saliva (60%), oral cleanliness (82.5%), the tongue (80%) and the use of dentures (71.4%). A high prevalence, 62.5% (n = 25), of opportunistic bacteria was found. The most commonly occurring bacteria groups were: (1) Candida albicans (47.5%) and (2) respiratory pathogens (37.5%) such as Klebsiella pneumoniae and Staphylococcus aureus.

Conclusion

Persons with dysphagia have poor oral hygiene which creates favourable environments for bacteria to flourish and increases the prevalence of pathogenic oral bacteria associated with the development of aspiration pneumonia. The management of oral health issues for persons with dysphagia should receive greater attention during hospitalisation.

Presence of non-oral bacteria in the oral cavity

A homeostatic balance exists between the resident microbiota in the oral cavity and the host. Perturbations of the oral microbiota under particular conditions can contribute to the growth of non-oral pathogens that are hard to kill because of their higher resistance to antimicrobials, raising the probability of treatment failure and reinfection. The presence of these bacteria in the oral cavity has been proven to be associated with several oral diseases such as periodontitis, caries, and gingivitis, and systemic diseases of importance in clinical medicine such as cystic fibrosis, HIV, and rheumatoid arthritis. However, it is still controversial whether these species are merely transient members or unique to the oral cavity. Mutualistic and antagonistic interactions between the oral microbiota and non-oral pathogens can also occur, though the mechanisms used by these bacteria are not clear. Therefore, this review presents an overview of the current knowledge about the presence of non-oral bacteria in the oral cavity, their relationship with systemic and oral diseases, and their interactions with oral bacteria.

Trypsin-Like Activity in Oral Cavity Is Associated with Risk of Fever Onset in Older Residents of Nursing Homes: An 8-Month Longitudinal Prospective Cohort Pilot Study

This study aimed to evaluate the association between trypsin-like activity in the oral cavity and the onset of fever in independent older residents of nursing homes. Independent older residents aged ≥ 65 years in 10 nursing homes were included in this study, which was conducted in Kitakyushu, Japan. For 8 months, follow-up dates on which the body temperatures of participants were more than 37.2 °C were noted. Trypsin-like activity in the oral cavity was detected by ADCHECK® with five-grade evaluation at baseline. Data from 53 independent participants with median age 89.0 (67–102) years were available for analysis. ADCHECK® scores were associated with fever days (r = 0.312, p = 0.029). The average periods until the onset of fever in participants with ADCHECK® Scores 1 and 2, Score 3, and Scores 4 and 5 were 6.6 ± 0.5, 5.0 ± 0.7, and 4.1 ± 1.0 months, respectively. ADCHECK® Scores 4 and 5 signified a higher risk of fever compared to ADCHECK® Scores 1 and 2 (hazards ratio 5.9, 95% confidence interval 1.4–23.9, p = 0.013), adjusted for possible confounders. We concluded that trypsin-like activity in the oral cavity was associated with the risk of fever in independent older residents of nursing homes.

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 care quality-Do humanity aspects matter? Nursing staff's and older people's perceptions

AIM

(a) To describe and compare perceptions of humanity aspects of oral care quality in relation to nursing staff in short-term care units and intensive care units and older people in short-term care units and their person-related conditions; and (b) to compare humanity aspects of oral care quality perceptions between nursing staff and older people in short-term care units.

DESIGN

Cross-sectional study. Self-reported questionnaire and clinical assessments.

METHODS

Nursing staff (N = 417) and older people (N = 74) completed the modified Quality of Care from a Patient Perspective instrument and person-related items. Older people's oral health status was clinically assessed using the Revised Oral Assessment Guide. Data were analysed using descriptive and analytic statistics. The data were collected from 2013-2016.

RESULTS

Nursing staff's perceptions of humanity aspects of oral care quality were related to gender, work role and care environment. Older people's perceptions of humanity aspects of oral care quality were related to self-reported physical health. Nursing staff in short-term care units perceived the subjective importance of humanity aspects of oral care quality higher compared with older people in short-term care units.

Exploring the putative interactions between chronic kidney disease and chronic periodontitis

Chronic kidney disease (CKD) and chronic periodontitis (CP) are both common diseases, which are found disproportionately comorbid with each other and have been reported to have a detrimental effect on the progression of each respective disease. They have an overlap in risk factors and both are a source of systemic inflammation along with a wide selection of immunological and non-specific effects that can affect the body over the lifespan of the conditions. Previous studies have investigated the directionality of the relationship between these two diseases; however, there is a lack of literature that has examined how these diseases may be interacting at the localized and systemic level. This review discusses how oral microorganisms have the ability to translocate and have distal effects and provides evidence for microbial involvement in a systemic disease. Furthermore, it summarizes the reported local and systemic effects of CKD and CP and discusses how the interaction of these effects may be responsible for directionality associations reported.

Non-oral, aerobic, Gram-negative bacilli in the oral cavity of Thai HIV-positive patients on Highly-active anti-retrovirus therapy medication

In the present study, we identified and evaluated the antibiotic susceptibility of 96 independent, aerobic, Gram-negative bacillus isolates from 255 Thai HIV-positive adults who were on Highly-active anti-retrovirus therapy (HAART) medication. Another 46 isolates from HIV non-HAART individuals, vertically transmitted HIV-positive individuals, and non-HIV controls were included for comparison. A total of 103 strains were tested for antibiotic susceptibility using disc diffusion for screening and E-test for minimal inhibitory concentration determination, with special attention on extended-spectrum beta-lactamase (ESBL) isolates. Pseudomonas aeruginosa, Pseudomonas luteola, Burkholderia cepacia, Aeromonas hydrophila, Klebsiella, and Enterobacter species were the most common bacteria. All strains were resistant against penicillin, amoxicillin, clindamycin, and metronidazole. No ESBL isolates were found.

Effect of oral hygiene programmes on oral opportunistic pathogens during stroke rehabilitation

OBJECTIVES

This study was to assess the effectiveness of a conventional oral hygiene care programme (COHCP) and an advanced oral hygiene care programme (AOHCP) on prevalence and viable counts of oral opportunistic pathogens among patients undergoing stroke rehabilitation.

METHODS

A total of 94 patients were randomized to two groups. Subjects were block randomized to either (a) COHCP: manual toothbrushing with oral hygiene instruction (OHI); or (b) AOHCP: powered toothbrushing, mouthrinsing with chlorhexidine and OHI. Prevalence and viable counts of oral opportunistic pathogens including yeasts, aerobic and facultative anaerobic gram-negative bacilli, Staphylococcus aureus, were assessed at baseline, the end of 3 and 6 months.

RESULTS

No significant difference was observed in the prevalence of oral opportunistic pathogens within each group over the clinical trial period. A significant decrease in the viable counts of S. aureus was found over the clinical trial period within AOHCP group (p < 0.05), while the viable counts of yeasts and anaerobic gram-negative bacillus (AGNB) remained stable within each group. Regression analysis failed to detect an association between intervention and the prevalence/viable counts of oral opportunistic pathogens.

CONCLUSIONS

Neither oral healthcare programme significantly affects AGNB, yeast or S. aureus over the study period in terms of prevalence and viable counts.

Effect of A Minimal-Massive Intervention in Hospitalized Older Patients with Oropharyngeal Dysphagia: A Proof of Concept Study

BACKGROUND

Oropharyngeal dysphagia (OD) is a newly defined geriatric syndrome that causes nutritional and respiratory complications in older hospitalized patients. Following hospital discharge, OD also causes hospital readmission and mortality in this population.

OBJECTIVE

Our aim was to assess the effect of a minimal-massive intervention (MMI) in reducing nutritional and respiratory complications in older hospitalized patients with OD.

DESIGN AND PARTICIPANTS

An open label trial was performed on 186 hospitalized older patients (>70y) with OD; 62 of these patients with OD were treated with the MMI and paired by sex, age, functionality, comorbidities and body mass index with two controls.

INTERVENTION

The MMI consisted of: a) fluid thickening and texture-modified foods, b) caloric and protein supplementation; and c) oral health and hygiene recommendations during hospitalization and following discharge. The control group followed the standard clinical practice without MMI.

MEASUREMENTS

Main study outcomes were hospital readmissions, respiratory infections, nutritional status and survival after 6 months follow up.

RESULTS

Both groups had similar advanced age (84.87±6.02MMI and 84.42±5.31 years), poor functionality (Barthel 59.51±26.76 MMI and 58.84±26.87), and high comorbidities (Charlson 3.00±1.60 MMI and 3.06±1.45). Main results showed that MMI improved nutritional status (MNA 9.84±2.05 pre-MMI vs. 11.31±2.21 post-MMI; p=0.0038) and functionality (Barthel 62.34±25.43 pre-MMI vs. 73.44±25.19 post-MMI; p=0.007). In addition MMI decreased hospital readmissions (68.8 readmissions/100 persons-year (28.1-109.38) MMI vs. 190.8 (156.0-225.7); p=0.001), respiratory infections (12.50 readmissions/100 persons-year (0-29.82) MMI vs. 74.68 (52.86-96.50); p=0.002), and increased 6-month survival (84.13% MMI vs. 70.96%; p=0.044).

CONCLUSIONS

Our results suggest that a MMI in hospitalized older patients with OD improves nutritional status and functionality and reduces hospital readmissions, respiratory infections and mortality. MMI might become a new simple and cost-effective strategy to avoid OD complications in the geriatric population admitted with an acute disease to a general hospital.

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.

High prevalence of colonization of oral cavity by respiratory pathogens in frail older patients with oropharyngeal dysphagia

BACKGROUND

Aspiration pneumonia (AP) is caused by dysfunctional swallowing resulting in aspiration of material colonized by respiratory pathogens. The aim of this study was to assess and compare the swallowing physiology, health status, oral health status, and oral/nasal microbiota in frail older patients (FOP) with oropharyngeal dysphagia (OD) and a control group.

METHODS

We studied 47 FOP (>70 year) with OD by videofluoroscopy (17 with acute pneumonia -APN-, 15 with prior pneumonia-PNP- and 15 without) and 14 older controls without OD (H). Oral/nasal colonization by five respiratory pathogens was evaluated by qPCR, whereas commensal microbiota composition was assessed by pyrosequencing.

KEY RESULTS

(i) Frail older patients with OD presented similar comorbidities, poor functionality, polymedication, and prevalent videofluoroscopic signs of impaired safety of swallow (33.3-61.5%). However, patients with OD-APN also presented malnutrition, delayed laryngeal vestibule closure (409.23 ± 115.6 ms; p < 0.05), and silent aspirations (15.6%). (ii) Oral health was poor in all groups, 90% presented periodontitis and 72%, caries. (iii) Total bacterial load was similar in all groups, but higher in the oropharynx (>10(8) CFU/mL) than in the nose (<10(6) CFU/mL) (p < 0.0001). Colonization by respiratory pathogens was very high: 93% in OD patients (p < 0.05 vs H); 93% in OD-PNP (p < 0.05 vs H); 88% in OD-APN (p = 0.07 vs H), and lower in controls (67%).

CONCLUSIONS & INFERENCES

Frail older patients with OD had impaired health status, poor oral health, high oral bacterial load, and prevalence of oral colonization by respiratory pathogens and VFS signs of impaired safety of swallow, and were therefore at risk for contracting AP.

Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus

Objective

The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers.

Materials and methods

A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins) and sea, seb, sec, tst, eta, etb, pvl (toxins). MIC₉₀ and MIC₅₀ were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin.

Results

While the hemolytic phenotype was significantly (p<0.001) more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL) genotype was found in 73–100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA) strains were identified, two from oral infections and one from a Thai HIV patient.

Conclusions

S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral infections and complaints and the antibiotic susceptibility (including MRSA) should regularly be checked. The frequent presence of S. aureus, although in low numbers among students and staff, emphasizes the importance of standard infection control precautions and of using diagnostic test in the dental clinic.

Effects of professional oral health care on elderly: randomized trial

OBJECTIVE

To better understand the role of the professional oral health care for elderly in improving geriatric oral health, the effects of short-term professional oral health care (once per week for 1 month) on oral microbiological parameters were assessed.

METHODS

Parallel, open-labelled, randomize-controlled trial was undertaken in a nursing home for elderly in Shizuoka, Japan. Thirty-four dentate elderly over 74 years were randomly assigned from ID number to the intervention (17/34) and control (17/34) groups. The outcomes were changes in oral microbiological parameters (number of bacteria in unstimulated saliva; whole bacteria, Streptococcus, Fusobacterium and Prevotella: opportunistic pathogens detection: and index of oral hygiene evaluation [Dental Plaque Index, DPI]) within the intervention period. Each parameter was evaluated at before and after intervention period. Four elderly were lost from mortality (1), bone fracture (1), refused to participate (1) and multi-antibiotics usage (1). Finally, 30 elderly were analysed (14/intervention and 16/control).

RESULTS

At baseline, no difference was found between the control and intervention groups. After the intervention period, the percentage of Streptococcus species increased significantly in the intervention group (Intervention, 86% [12/14]; Control, 50% [8/16]: Fisher's, right-tailed, P < 0.05). Moreover, DPI significantly improved in the intervention group (Intervention, 57% [8/14]; Control, 13% [2/16]: Fisher's, two-tailed, P < 0.05). The improvement in DPI extended for 3 months after intervention. None of side effects were reported.

CONCLUSION

The short-term professional oral health care can improve oral conditions in the elderly.

Oral health in older patients with oropharyngeal dysphagia

BACKGROUND

oropharyngeal dysphagia (OD), aspiration and poor oral health status are potential risk factors in elderly patients with aspiration pneumonia (AP).

AIM

to assess the oral hygiene status and the prevalence of periodontal disease and dental caries in elderly patients with OD.

PATIENTS AND METHODS

fifty elderly patients (79.7 ± 6.64 years) with OD associated with ageing or neurological diseases and 15 elderly patients without OD (77.01 ± 4.51 years) were enrolled in this observational-transversal study. OD and aspiration were evaluated by videofluoroscopy (VFS). Oral health was assessed by: (i) the Simplified Oral Hygiene Index (OHI-S); (ii) a complete periodontal examination, assessing the periodontal pocket depth, clinical attachment loss and bleeding on probing to study periodontal diseases (periodontitis, gingivitis); and (iii) the presence of dental caries.

RESULTS

8/50 elderly patients with OD presented VFS signs of aspiration, half of them silent; 40/50, signs of penetration into laryngeal vestibule and 16/50, oropharyngeal residue. Prevalence of edentulism and caries was higher in patients with OD. Dentate older patients with OD (30/50) presented the following complications (i) poor oral hygiene in 18 patients (OHI-S 3.1-6), (ii) gingivitis in 2 and periodontitis in 28 and (iii) caries in 16.

CONCLUSIONS

older patients with OD presented polymorbidity and impaired health status, high prevalence of VFS signs of impaired safety of swallow and poor oral health status with high prevalence of periodontal diseases and caries. These patients are at great risk of developing AP. We recommend a policy of systematic oral health assessment in elderly patients with OD.

Quantitative detection of Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa in human oral epithelial cells from subjects with periodontitis and periodontal health

Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33% of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15% of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6% of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57% and 50% of patients, respectively, with probing depth and clinical attachment level ≥6 mm, no correlation was found with age, sex, bleeding on probing or the presence of supragingival biofilm. The prevalence of these pathogens in epithelial cells is correlated with the state of periodontal disease.

Transplantation-associated long-term immunosuppression promotes oral colonization by potentially opportunistic pathogens without impacting other members of the salivary bacteriome

Solid-organ transplant recipients rely on pharmacological immunosuppression to prevent allograft rejection. The effect of such chronic immunosuppression on the microflora at mucosal surfaces is not known. We evaluated the salivary bacterial microbiome of 20 transplant recipients and 19 nonimmunosuppressed controls via 454 pyrosequencing of 16S rRNA gene amplicons. Alpha-diversity and global community structure did not differ between transplant and control subjects. However, principal coordinate analysis showed differences in community membership. Taxa more prevalent in transplant subjects included operational taxonomic units (OTUs) of potentially opportunistic Gammaproteobacteria such as Klebsiella pneumoniae, Pseudomonas fluorescens, Acinetobacter species, Vibrio species, Enterobacteriaceae species, and the genera Acinetobacter and Klebsiella. Transplant subjects also had increased proportions of Pseudomonas aeruginosa, Acinetobacter species, Enterobacteriaceae species, and Enterococcus faecalis, among other OTUs, while genera with increased proportions included Klebsiella, Acinetobacter, Staphylococcus, and Enterococcus. Furthermore, in transplant subjects, the dose of the immunosuppressant prednisone positively correlated with bacterial richness, while prednisone and mycophenolate mofetil doses positively correlated with the prevalence and proportions of transplant-associated taxa. Correlation network analysis of OTU relative abundance revealed a cluster containing potentially opportunistic pathogens as transplant associated. This cluster positively correlated with serum levels of C-reactive protein, suggesting a link between the resident flora at mucosal compartments and systemic inflammation. Network connectivity analysis revealed opportunistic pathogens as highly connected to each other and to common oral commensals, pointing to bacterial interactions that may influence colonization. This work demonstrates that immunosuppression aimed at limiting T-cell-mediated responses creates a more permissive oral environment for potentially opportunistic pathogens without affecting other members of the salivary bacteriome.

Host defense proteins derived from human saliva bind to Staphylococcus aureus

Proteins in human saliva are thought to modulate bacterial colonization of the oral cavity. Yet, information is sparse on how salivary proteins interact with systemic pathogens that transiently or permanently colonize the oral environment. Staphylococcus aureus is a pathogen that frequently colonizes the oral cavity and can cause respiratory disease in hospitalized patients at risk. Here, we investigated salivary protein binding to this organism upon exposure to saliva as a first step toward understanding the mechanism by which the organism can colonize the oral cavity of vulnerable patients. By using fluorescently labeled saliva and proteomic techniques, we demonstrated selective binding of major salivary components by S. aureus to include DMBT1(gp-340), mucin-7, secretory component, immunoglobulin A, immunoglobulin G, S100-A9, and lysozyme C. Biofilm-grown S. aureus strains bound fewer salivary components than in the planctonic state, particularly less salivary immunoglobulins. A corresponding adhesive component on the S. aureus surface responsible for binding salivary immunoglobulins was identified as staphylococcal protein A (SpA). However, SpA did not mediate binding of nonimmunoglobulin components, including mucin-7, indicating the involvement of additional bacterial surface adhesive components. These findings demonstrate that a limited number of salivary proteins, many of which are associated with various aspects of host defense, selectively bind to S. aureus and lead us to propose a possible role of saliva in colonization of the human mouth by this pathogen.

Identification of oral bacteria by 16S rRNA gene analysis in elderly persons requiring nursing care

After incubation of saliva from 58 semi-bedridden elderly persons, the cultures were identified based on the 16S rRNA gene base sequence to compare the identification by the conventional culture method. As a result, the 16S rRNA gene base sequence of 198 strains identified by the culture method showed 98.5% or more homology in some of the Human Oral Microbiome database, and the identification of bacterial species and genus was possible. When an organism identified by the 16S rRNA gene sequencing method was compared with that by the culture method, the concordance rates were 54.5% at the genus level and 35.9% at the species level. Streptococcus mitis strains most frequently isolated from saliva that were identified by the culture method were identified as the same species by the 16S rRNA gene sequencing method (32/35), and all the 11 Streptococcus salivarius strains identified by the culture method were identified as the same species by the 16S rRNA gene sequencing method. All the strains identified as Streptococcus anginosus group by the culture method and 8 of the 9 strains identified as Prevotella species by the culture method were identified as the same group and genus by the 16S rRNA gene sequencing method. When an oral microbial flora test with saliva samples from elderly persons is performed, the 16S rRNA gene sequence identification enables us to identify major indigenous bacteria and pathogenic bacteria and is considered useful as a means of supplementing the conventional culture method.