Prevalence of potential respiratory pathogens in the mouths of elderly patients and effects of professional oral care

The impact of oral diseases on respiratory health and the influence of respiratory infections on the oral microbiome

OBJECTIVE

The objective of this review is to examine the relationship between oral diseases and respiratory health, investigating how oral microbiome disruptions contribute to respiratory tract infections. Additionally, it aims to explore the impact of respiratory disease symptoms and treatments on the oral microbiome.

DATA SOURCES

The literature utilized in this review was sourced from studies focusing on the correlation between oral health and respiratory infections, spanning a period of 40 years. Various databases and scholarly sources were likely consulted to gather relevant research articles, reviews, and clinical studies.

STUDY SELECTION

This review summarizes four decades-long research, providing insights into the intricate relationship between oral and respiratory health. It delves into how oral diseases influence respiratory tract conditions and vice versa. The selection process likely involved identifying studies that addressed the interaction between oral microbiome disruptions and respiratory complications.

CONCLUSION

Oral diseases or poor oral habits have been known to increase the risk of getting respiratory infections. Modern techniques have demonstrated the relationship between oral disease and respiratory tract infections like influenza, chronic obstructive pulmonary diseases, asthma, and Pneumonia. Apart from that, the medications used to treat respiratory diseases affect oral physiological factors like the pH of saliva, and saliva flow rate, which can cause significant changes in the oral microbiome. This review provides regular oral hygiene and care that can prevent respiratory health and respiratory infections.

CLINICAL SIGNIFICANCE

Understanding the intricate relationship between oral health and respiratory infections is crucial for healthcare providers. Implementing preventive measures and promoting good oral hygiene habits can reduce respiratory tract infections and improve overall respiratory health outcomes.

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.

Evaluation of brushing efficiency in reducing oral microbiota in mechanically ventilated patients admitted to an intensive care unit

Background

Patients admitted to the Intensive Care Unit (ICU) are at greater risk of developing nosocomial infections due to their investigations, treatment and changes in the immune system. One of the most prevalent nosocomial infections is respiratory tract infection, such as hospital acquired pneumonia and ventilator-associated pneumonia (VAP). The bacteria commonly found in the oral cavity in the hospital environment are Streptococcus viridians, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus spp., and Klebsiella pneumoniae. There is a need to test and define appropriate standard protocols for oral hygiene in patients undergoing mechanical ventilation in ICUs through the intervention of a dental specialist, preventing the proliferation of microorganisms into the respiratory tract, thus reducing hospitalization time, the use of antibiotics, and increased morbidity/mortality. Objective: This study aimed to evaluate the effectiveness of dental brushing in the reduction of the pathogenic buccal microbiota associated with mechanical ventilation in patients admitted to the Evangelical Hospital from Londrina, Paraná, Brazil.

Methodology

The sample consisted of 90 patients (of both sexes), mean age of 65 years, under mechanical ventilation by orotracheal tube and tracheostomized patients, without suspected or confirmed diagnosis of pneumonia. Patients were randomized ∗∗∗.

Results

Results showed that oral hygiene using a toothbrush by suction, with chlorhexidine gel 0.12% (Group B), was more effective than conventional hygiene using gauze soaked with chlorhexidine 0.12% (Group A) in reducing pathogenic buccal microbiota.

Conclusions

There was a reduction of the pathogenic buccal microbiota in mechanically ventilated patients receiving oral hygiene using a toothbrush by suction with chlorhexidine gel 0.12% (Group B).

Pneumonia incidence and oral health management by dental hygienists in long-term care facilities: A 1-year prospective multicentre cohort study

OBJECTIVE

To investigate the association between oral health management (OHM) by dental hygienists and the occurrence of pneumonia, and determine the effectiveness of OHM in pneumonia prevention.

BACKGROUND

In long-term care facilities in Japan, the need for professional OHM is increasing with an increase in the number of severely debilitated residents.

MATERIALS AND METHODS

A 1-year prospective multicentre cohort study was conducted using data from 504 residents (63 men; mean age: 87.4 ± 7.8 years) in Japanese long-term care facilities. Basic information, medical history, willingness to engage in oral hygiene behaviour, need for OHM and oral conditions were investigated at baseline. In addition, information on the occurrence of pneumonia was collected using a follow-up survey after one year. A Poisson regression analysis with robust standard errors was conducted, with pneumonia as the dependent variable, and factors associated with OHM and pneumonia occurrence as explanatory variables.

RESULTS

Overall, 349 (69.2%) residents required OHM by dental hygienists during that year of follow-up. Of those, 238 (68.2%) were provided with OHM, and 18 (7.5%) developed pneumonia. Among the 111 patients (31.8%) who were not provided with OHM, 21 (18.9%) developed pneumonia. The OHM group had lower pneumonia rates than the non-OHM group (prevalence rate ratio: 0.374; 95% CI: 0.210-0.665).

CONCLUSION

Oral health management by dental hygienists was associated with a lower incidence of pneumonia among residents of long-term care facilities, underlining the importance of professional OHM for such individuals. It is recommended that OHM be practised routinely in long-term care facilities.

Distribution of Yeast Species and Risk Factors of Oral Colonization after Oral-Care Education among the Residents of Nursing Homes

Most yeasts causing infections in humans are part of commensal microflora and etiological agents of different infections when hosts become susceptible, usually due to becoming immunocompromised. The colonization of potentially pathogenic microbes in the oral cavity is increased by poor oral hygiene. This follow-up survey was conducted approximately two months after providing information on proper oral care at 10 nursing homes in Taiwan. Among the 117 of 165 residents colonized by yeasts, 67 were colonized by more than one yeast species. A total of 231 isolates comprising eight fungal genera and 25 species were identified. Candida albicans (44.6%) was the dominant species, followed by Candida glabrata (17.7%), Candida parapsilosis (8.7%), Candida tropicalis (7.8%), and Candida pararugosa (7.3%). Residents having a yeast colony-forming unit >10 (OR, 8.897; 95% CI 2.972−26.634; p < 0.001) or using a wheelchair (OR, 4.682; 95% CI 1.599−13.705; p = 0.005) were more likely to be colonized by multiple species. By comparing before and after oral-care education, dry mouth (OR, 3.199; 95% CI 1.448−7.068; p = 0.011) and having heart disease (OR, 2.681; 95% CI 1.068−6.732; p = 0.036) emerged as two independent risk factors for increased density of colonizing yeast.

Predictors of early postoperative pneumonia after oncologic surgery with the patients receiving professional oral health care: A prospective, multicentre, cohort study

This study was a prospective, multicentre, cohort study on 685 patients who had undergone oncologic surgery. The patients were divided into two groups according to the presence or absence of postoperative pneumonia. The two groups were compared with respect to their background, index operation, food eaten, oral condition, contents of oral care and dental treatment, laboratory data, and bacterial flora. All postoperative pneumonias occurred in six cases within four days postoperatively. The multivariable logistic regression analysis showed that preoperative serum C-reactive protein was the strongest predictor of postoperative pneumonia. In addition, decreased postoperative Candida albicans colonies was an effective predictor of postoperative pneumonia. For patients with predictors of postoperative pneumonia, perioperative strategies for its prevention should be considered in addition to professional oral health care. This study was approved by the National Hospital Organization's Central Ethics Review Board and was also approved by the directors of the participating institutions.

The effect of oral care intervention on pneumonia hospitalization, Staphylococcus aureus distribution, and salivary bacterial concentration in Taiwan nursing home residents: a pilot study

Background

Elevated Staphylococcus aureus and oral bacterial concentrations are known to correlate with pneumonia hospitalization in nursing home residents. However, the effects of a professional oral care intervention on these factors remain unclear. The aims of this quasi-experimental study were to compare bacterial concentrations in saliva and sputum, oral health status, distribution of Staphylococcus aureus, and pneumonia status before and after a professional oral care intervention.

Methods

A purposive sample of residents from two nursing homes was divided into an intervention group that received a weekly professional oral care intervention and a control group. Oral bacterial concentration was determined by real-time polymerase chain reaction. The Staphylococcus aureus distribution was determined by bacterial culture and matrix-assisted laser desorption/ionization–time of flight mass spectrometry. After data collection, a statistical analysis was performed to evaluate the effect of the intervention.

Results

Most residents were unconscious (80%), and most had a history of pneumonia (76%). Baseline demographic data did not significantly differ between the two groups. After the intervention, the intervention group had significant improvements in plaque index (1.66 ± 0.78 vs. 0.94 ± 0.64, p <  0.01), gingival index (2.36 ± 0.76 vs. 1.65 ± 0.83, p <  0.01), tongue coating index (0.96 ± 1.10 vs. 0.16 ± 0.47, p <  0.01), distribution of Staphylococcus aureus in salivary samples (11.11 ± 14.47% vs. 1.74 ± 3.75%, p = 0.02), and salivary bacterial concentration ([4.27 ± 3.65] × 10⁵ vs. [0.75 ± 1.20] × 10⁵, p <  0.01). Sputum bacterial concentration did not significantly differ. The intervention group also had a significantly lower annual prevalence of pneumonia hospitalization (1.24 ± 1.51 vs. 0.48 ± 0.59, p = 0.01), especially in residents whose salivary bacterial concentration exceeded the median. However, the duration of pneumonia hospitalization did not significantly differ between the two groups.

Conclusion

A professional oral care intervention in nursing home residents can improve oral health, reduce levels of salivary bacteria and Staphylococcus aureus, and decrease the annual prevalence of pneumonia hospitalization.

Trial registration

Trial registration: ClinicalTrials.gov, NCT03874962. Registered 12 March 2019 - Retrospectively registered.

Subgingival microbiome in Chinese patients with generalized aggressive periodontitis compared to healthy controls

OBJECTIVE

The aim of the study was to profile the subgingival microbiome of Chinese adults with generalized aggressive periodontitis (GAgP) using human oral microbe identification microarray (HOMIM), and to compare the results with matched periodontal healthy controls.

DESIGN

15 subjects with GAgP and 15 age- and gender- matched periodontal healthy controls were included. Subgingival plaque samples were collected from the deepest pockets of patients with GAgP and matched sites in controls and then analyzed by 16S rRNA-based microarrays. Student's paired t-test was used to compare clinical parameters and mean number of bacterial taxa detected between the two groups. Fisher's exact probability test and Wilcoxon Rank Sum were used to compare bacterial species between all samples. A multiple linear regression model was used for correlations among age, gender and bacterial with clinical parameters.

RESULTS

From a total sum of 379 strains tested, 171 bacterial strains were detected from subgingival plaques of the GAgP patients, more than the 157 strains detected in control group. Mean number of subgingival bacterial taxa detected in GAgP group was 68 (SD = 21.06) while in control group was 45 (SD = 21.60). 47 bacterial taxa were detected more frequently in GAgP group while 12 taxa were more prevalent in control group. The significantly more prevalent and abundant taxa of bacteria in GAgP group included Filifactor alocis, Desulfobulbus sp., Fretibacterium sp., Porphyromonas gingivalis, Tannerella forsythia, Porphyromon as endodontalis, Peptostreptococcaceae spp., Parvimonas micra, Eubacterium nodatum and Eubacterium saphenum. Meanwhile the more abundant taxa in control group were Streptococcus spp. and Pseudomonas aeruginosa.

CONCLUSIONS

There are more taxa of bacteria in subgingival plaques of Chinese patients with GAgP than in healthy controls. F. alocis, Desulfobulbus sp., Fretibacterium sp., P. gingivalis and T. forsythia are strongly associated with GAgP. High-throughout microbiological results may help dentists have a better understanding of subgingival microbiome of GAgP.

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.

Factors That Affect Oral Care Outcomes for Institutionalized Elderly

The aim of this study was to evaluate the effect of an oral care intervention program on the incidence of pneumonia and fever as a surrogate endpoint. In addition, we tried to determine the oral care risk factors for the incidence of fever. We provided an oral care program for the elderly at one private nursing home in July 2013. The maximum capacity of the nursing home was 60 residents. The body temperatures of all residents were measured twice a day and were summarized as the incidence of fever over a one-month period, which was used as the dependent variable. The residents' life conditions, number of teeth, and prescribed diet were used as independent variables. The factors that affected the incidence of fever were the number of remaining teeth, a prescribed diet of sliced food, the meal care level, and the oral Candida levels. These risk factors affected the incidence of fever independently or interactively with oral care. Some risk factors for the incidence of fever were enhanced by the oral care program. It is important to evaluate and control these factors before the implementation of an oral care program.

A new oral care gel to prevent aspiration during oral care

AIM

Although oral care is important in the prevention of aspiration pneumonia, the different institutions and practitioners employ various oral care methods, some of which are associated with the risk of aspiration. We have developed a new gel with the physical properties needed for waterless oral care. In the present study, we evaluated and investigated the properties and effectiveness of this gel.

METHODS

The physical properties of the trial gel and commercial moisturizing gels were compared using a VAS scale. The effects of plaque elimination were evaluated in healthy volunteers. Brushing was carried out by a dental hygienist using the gel and water. The number of throat suctions performed during brushing was also counted, and the difference was evaluated.

RESULTS

In the evaluation of physical characteristics, trial Gel B showed a significantly higher rating than the other gels. In plaque elimination, the rate of decrease in a modified PCR was significantly greater with the gel trial. Suctioning was also performed significantly fewer times with the trial gel.

CONCLUSIONS

Good results were obtained with the newly developed trial Gel B with regard to the physical properties and the sensory evaluations. Its effectiveness was also confirmed in plaque elimination and in the evaluated risk of aspiration. The use of Gel B may have the potential to decrease the risk of aspiration during oral care and reduce the occurrence of aspiration pneumonia.

Antibacterial activity on superhydrophobic titania nanotube arrays

Bacterial infections are a serious issue for many implanted medical devices. Infections occur when bacteria colonize the surface of an implant and form a biofilm, a barrier which protects the bacterial colony from antibiotic treatments. Further, the anti-bacterial treatments must also be tailored to the specific bacteria that is causing the infection. The inherent protection of bacteria in the biofilm, differences in bacteria species (gram-positive vs. gram-negative), and the rise of antibiotic-resistant strains of bacteria makes device-acquired infections difficult to treat. Recent research has focused on reducing biofilm formation on medical devices by modifying implant surfaces. Proposed methods have included antibacterial surface coatings, release of antibacterial drugs from surfaces, and materials which promote the adhesion of non-pathogenic bacteria. However, no approach has proven successful in repelling both gram-positive and gram-negative bacteria. In this study, we have evaluated the ability of superhydrophobic surfaces to reduce bacteria adhesion regardless of whether the bacteria are gram-positive or gram-negative. Although superhydrophobic surfaces did not repel bacteria completely, they had minimal bacteria attached after 24 h and more importantly no biofilm formation was observed.

Denture Stomatitis: Causes, Cures and Prevention

Removable dentures are worn by 20% of the UK population and two thirds of these individuals have denture stomatitis. Poor oral hygiene is commonplace among this group, as is smoking and xerostomia, which also contribute to the development of denture stomatitis. A complex polymicrobial biofilm is able to proliferate on the surface of denture materials and matures to form visible denture plaque. This denture plaque biofilm stimulates a local inflammatory process that is detectable clinically as erythema, and hyperplasia. Systemically, denture plaque represents a potential risk factor for systemic disease, in particular aspiration pneumonia. Respiratory pathogens have been detected in the denture plaque and overnight denture wear has been linked to an increased risk of aspiration pneumonia. There is a general lack of evidence on the adequate management of denture stomatitis and we present a protocol for use in the primary care setting.

Halitosis and associated factors in institutionalized elderly persons

Abstract Objective: to evaluate the prevalence of halitosis and associated factors in institutionalized elderly persons. Methods: a sectional study was performed with 268 elderly persons from 11 long-term care institutions in Natal in the northeast of Brazil. Data collection included an oral epidemiologic examination and questions about self-perception of oral health, as well as a consultation of medical records and the application of a questionnaire to the directors of the institutions. Halitosis was measured using the organoleptic test. The independent variables were oral, sociodemographic, institutional, general health and functional conditions. Bivariate analysis was performed using the Pearson chi-square test and Fisher's exact test, and the magnitude of effect was verified by the prevalence ratio for the independent variables in relation to the outcome, with a 95% confidence level. Results: the prevalence of halitosis was 26.1%, which was exhaled by the mouth in 98.57% of cases and by the nose in 10% of cases. Prevalence was 43% higher among non-white individuals (p=0.006); 65% higher among those living in non-profit institutions (p=0.039); 52% higher in elderly persons with oriented cognitive status (p=0.047); 41% higher in elderly persons with root caries (p=0.029); 62% higher in those who did not use dentures (p=0.046); 57% lower in edentulous persons (p<0.001); and 73% higher in elderly individuals with tongue biofilm (p=0.001). Conclusion: The occurrence of halitosis in institutionalized elderly persons was similar to other studies, but there was an expressive number of extrabuccal cases and an association with oral health problems, as well as sociodemographic, institutional and functional factors.

Fungal Biofilms and Polymicrobial Diseases

Biofilm formation is an important virulence factor for pathogenic fungi. Both yeasts and filamentous fungi can adhere to biotic and abiotic surfaces, developing into highly organized communities that are resistant to antimicrobials and environmental conditions. In recent years, new genera of fungi have been correlated with biofilm formation. However, Candida biofilms remain the most widely studied from the morphological and molecular perspectives. Biofilms formed by yeast and filamentous fungi present differences, and studies of polymicrobial communities have become increasingly important. A key feature of resistance is the extracellular matrix, which covers and protects biofilm cells from the surrounding environment. Furthermore, to achieve cell–cell communication, microorganisms secrete quorum-sensing molecules that control their biological activities and behaviors and play a role in fungal resistance and pathogenicity. Several in vitro techniques have been developed to study fungal biofilms, from colorimetric methods to omics approaches that aim to identify new therapeutic strategies by developing new compounds to combat these microbial communities as well as new diagnostic tools to identify these complex formations in vivo. In this review, recent advances related to pathogenic fungal biofilms are addressed.

Dynamics of biofilm formation and the interaction between Candida albicans and methicillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA)

Polymicrobial biofilms are an understudied and a clinically relevant problem. This study evaluates the interaction between C. albicans, and methicillin- susceptible (MSSA) and resistant (MRSA) S. aureus growing in single- and dual-species biofilms. Single and dual species adhesion (90 min) and biofilms (12, 24, and 48 h) were evaluated by complementary methods: counting colony-forming units (CFU mL-1), XTT-reduction, and crystal violet staining (CV). The secretion of hydrolytic enzymes by the 48 h biofilms was also evaluated using fluorimetric kits. Scanning electron microscopy (SEM) was used to assess biofilm structure. The results from quantification assays were compared using two-way ANOVAs with Tukey post-hoc tests, while data from enzymatic activities were analyzed by one-way Welch-ANOVA followed by Games-Howell post hoc test (α = 0.05). C. albicans, MSSA and MRSA were able to adhere and to form biofilm in both single or mixed cultures. In general, all microorganisms in both growth conditions showed a gradual increase in the number of cells and metabolic activity over time, reaching peak values between 12 h and 48 h (ρ<0.05). C. albicans single- and dual-biofilms had significantly higher total biomass values (ρ<0.05) than single biofilms of bacteria. Except for single MRSA biofilms, all microorganisms in both growth conditions secreted proteinase and phospholipase-C. SEM images revealed extensive adherence of bacteria to hyphal elements of C. albicans. C. albicans, MSSA, and MRSA can co-exist in biofilms without antagonism and in an apparent synergistic effect, with bacteria cells preferentially associated to C. albicans hyphal forms.

Evaluation of application possibility of water containing organic acids for chemical denture cleaning for older adults

AIM

The purpose of the present study was to evaluate the application possibility of water containing organic acids (WOA), made by some organic acids used as food additives, for chemical denture cleaning for older adults by microbial investigation.

METHODS

Using an in vitro biofilm study, we determined the effects of WOA on Streptococcus sanguinis, S. pneumoniae and Candida albicans attached to heat-cured acrylic resins. Specimens were divided into three groups as follows: control group (TW), commercial denture cleaner group (DC) and WOA group (WOA). Specimens were treated with each for 5 min, 30 min or 8 h, and the numbers of attached microbes were determined by counting colony-forming units or adenosine triphosphate analysis. Using an in vivo biofilm study, we studied the effects of these same solutions on 60 complete dentures. The dentures were divided randomly and blindness into three groups as described above, and treated for 10 min. The numbers of microbes attached to dentures before and after treatment were determined by counting colony-forming units.

RESULTS

For the in vitro biofilm study, there were significant differences in the numbers of microbes between WOA and TW, although there were no significant differences between WOA and DC except for C. albicans. For the in vivo biofilm study, there were significant differences between WOA, DC and TW, although there was no significant difference between WOA and DC.

CONCLUSION

We conclude that water containing organic acids exerts antimicrobial effects as strong as commercial denture cleaner, and it has an application possibility of use for safe chemical denture cleaning for older adults.

Risk of Methicillin-Resistant Staphylococcus aureus Transmission in the Dental Healthcare Setting: A Narrative Review

Objective.

Information on the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection transmission in dental healthcare settings was incomplete only few years ago; therefore, MRSA infection control guidelines were necessarily based on data extrapolated from other fields. Recently, publication of specific studies have made it possible to review such risk.

Methods.

Studies of MRSA infection in dentistry were searched for using EMBASE, MEDLINE, and Google and were allocated into the following sections: (1) direct evidence: documented cases of MRSA transmission in dentistry; (2) indirect evidence: carriage rates among dental healthcare providers (DHCPs) and patients (high carriage rates suggest that transmission is likely); (3) speculative evidence: MRSA occurrence in the dental environment (high environmental contamination probably increases the risk of infection); and (4) speculative evidence: MRSA carriage in human dental plaque and saliva (oral carriers may spread MRSA in the environment during dental therapy, with consequent environmental contamination and probable increased risk of infection).

Results.

Our findings were as follows. First, transmission has been ascertained during surgical interventions, particularly in surgical units and among head and neck cancer patients. Second, carriage rates among DHCPs were lower than those among other healthcare workers. Carriage rates among adult patients were low, whereas among pedodontic and special care patients rates were higher than those in the general population. Third, MRSA has been detected in the environment of emergency and surgical units and in dental hospitals. Some individuals in poor general condition were oral MRSA carriers.

Conclusions.

The occupational risk of MRSA infection among DHCPs is minimal. Among special patients (eg, special care, hospitalized and cancer patients) the risk of infection is high, whereas among the remaining patients undergoing conventional therapy such risk is probably low.

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with chronic periodontal infection

P. aeruginosa and Acinetobacter spp. are important pathogens associated with late nosocomial pneumonia in hospitalized and institutionalized individuals. The oral cavity may be a major source of these respiratory pathogens, particularly in the presence of poor oral hygiene and periodontal infection. This study investigated the prevalence of P. aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with periodontal disease or health. Samples were obtained from 55 periodontally healthy (PH) and 169 chronic periodontitis (CP) patients. DNA was obtained from the samples and detection of P. aeruginosa and Acinetobacter spp. was carried out by multiplex and nested PCR. P. aeruginosa and Acinetobacter spp. were detected in 40% and 45% of all samples, respectively. No significant differences in the distribution of these microorganisms between men and women, subgingival biofilm and saliva samples, patients ≤ 35 and > 35 years of age, and smokers and non-smokers were observed regardless periodontal status (p > 0.05). In contrast, the frequencies of P. aeruginosa and Acinetobacter spp. in saliva and biofilm samples were significantly greater in CP than PH patients (p < 0.01). Smokers presenting P. aeruginosa and high frequencies of supragingival plaque were more likely to present CP than PH. P. aeruginosa and Acinetobacter spp. are frequently detected in the oral microbiota of CP. Poor oral hygiene, smoking and the presence of P. aeruginosa are strongly associated with periodontitis.

Oral care may reduce pneumonia in the tube-fed elderly: a preliminary study

Pneumonia is one of the most important diseases in terms of mortality in the elderly. In particular, bedridden patients who are forbidden oral ingestion during enteral nutrition may have a poor outcome resulting from a respiratory infection. Oral hygiene can play a positive role in preventing aspiration pneumonia in the elderly. The aim of this study was to investigate the effectiveness of oral hygiene for bedridden and tube-fed patients at an increased risk of pneumonia. This retrospective study was conducted from July 2011 to June 2013 on a long-term-care hospital unit. The oral care protocol (OCP) intervention commenced in July 2012, during the study period. The subjects of this study were 63 elderly patients with a mean age of 81.7 years. Thirty-one patients were enrolled in the OCP intervention group, and the mean observation length was 130.4 days; the mean observation length for the 32 patients in the control group was 128.4 days. The incidence of pneumonia and the numbers of days with a recorded fever, antibiotics administration, blood tests, and radiological examinations were reduced from 1.20 to 0.45, 24.57 to 17.48, 25.52 to 10.12, 10.91 to 6.54, and 6.33 to 3.09 %, respectively. These reductions were significantly less in the OCP intervention group. In conclusion, the results of the present study suggest that daily oral care for tube-fed patients who do not receive nutrition by mouth reduced the incidence of pneumonia. In addition to patients consuming food by mouth, all tube-fed patients require dedicated oral care to maintain healthy oral conditions.

Antiseptic effect of slightly acidic electrolyzed water on dental unit water systems

Biofilm formation in dental unit water systems (DUWSs) can contaminate water from three-in-one syringes, air rotors, and low-speed handpieces. This may serve as a potential source of infection for dentists, dental staff, and patients, so these systems must be sterilized. Because slightly acidic electrolyzed water (SAEW) is often used as a disinfectant for food, the aim of this study was to investigate the possibility of using SAEW as a DUWS disinfectant. Slightly acidic electrolyzed water was injected into a dental unit and its effects evaluated. Chemical properties such as chlorine ion and potential hydrogen in the SAEW were measured. Detection of both ordinary and heterotrophic bacteria from the DUWS was performed by culture, and biofilm formation of the bacteria in the DUWS evaluated. Polymerase chain reaction (PCR) was used to detected contamination by nosocomial pathogens. Almost all the chlorine ions in the SAEW were exhausted during the two-day trials, and the pH value of the SAEW fell from 5 to 4. No viable cells were detected in the SAEW collected. Biofilm formation in the water from the DUWS with SAEW was almost at a baseline level, whereas that without SAEW was 4 times higher. The PCR analysis showed that no nosocomial infecting pathogens were detected in the SAEW. The present study demonstrated the antiseptic effect of SAEW in DUWS.

Upper aero-digestive contamination by Pseudomonas aeruginosa and implications in Cystic Fibrosis

BACKGROUND

Cystic Fibrosis (CF) is a severe genetic disorder that is common among the Caucasian population. Bacterial respiratory infections are the main cause of morbidity and mortality in CF patients. Pseudomonas aeruginosa is the main pathogen of lower airways (LAW) decline.

METHOD

To understand chronic broncho-pulmonary colonization, a systematic review is conducted. The aim of our article is to identify the pathways of contamination in the upper aero-digestive tract.

RESULTS

A large number of articles report that P. aeruginosa is established first at nasopharyngeal sites. The vast majority of authors agree that the upper aero-digestive tract is the first location of colonization by P. aeruginosa and its presence appears to be predictive of subsequent broncho-pulmonary colonization.

CONCLUSION

This review supports the possible involvement of the nasal and paranasal sinuses and oral cavity as means of contamination.

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.

Effect of an oral hygienic care program for stroke patients in the intensive care unit

PURPOSE

The effects of an oral hygienic care program (OHCP) have been reported in several diseases. However, no study exists investigating the influence of an OHCP on stroke patients or patients in the intensive care unit (ICU) has been reported, thus we sought to investigate the potential effect of an OHCP.

MATERIALS AND METHODS

Fifty-six consecutive stroke patients who were admitted to the ICU were randomly assigned to two groups: the intervention (29 patients) and control groups (27 patients). The OHCP included tooth brushing with an inter-dental brush and tongue cleaner and cleaning with chlorhexidine was administered to patients by one dentist once per day during admission in the ICU (mean, 2.2 weeks). The plague index, gingival index, clinical attachment loss, and colonization degree of candida albicans were assessed.

RESULTS

After OHCP, the plaque index, gingival index, and colonization degree of candida albicans in saliva showed a significant decrease in the intervention group compared to those of the control group (p<0.05). However, no significant difference was observed in clinical attachment loss and the colonization degree of candida albicans on the tongue (p>0.05).

CONCLUSION

Our OHCP was effective in improving the oral hygienic status and periodontal health of stroke patients during their stay in the ICU. Therefore, we recommend administration of the OHCP for stroke patients during their stay in the ICU.

Effectiveness of oral hygiene interventions against oral and oropharyngeal reservoirs of aerobic and facultatively anaerobic gram-negative bacilli

BACKGROUND

Aerobic and facultatively anaerobic gram-negative bacilli (AGNB) are opportunistic pathogens and continue to cause a large number of hospital-acquired infections. AGNB residing in the oral cavity and oropharynx have been linked to nosocomial pneumonia and septicemia. Although AGNB are not considered members of the normal oral and oropharyngeal flora, medically compromised patients have been demonstrated to be susceptible to AGNB colonization.

METHODS

A literature search was conducted to retrieve articles that evaluated the effectiveness of oral hygiene interventions in reducing the oral and oropharyngeal carriage of AGNB in medically compromised patients.

RESULTS

Few studies have documented the use of mechanical oral hygiene interventions alone against AGNB. Although a number of studies have employed oral hygiene interventions complemented by antiseptic agents such as chlorhexidine and povidone iodine, there appears to be a discrepancy between their in vitro and in vivo effectiveness.

CONCLUSION

With the recognition of the oral cavity and oropharynx as a reservoir of AGNB and the recent emergence of multidrug and pandrug resistance in hospital settings, there is a pressing need for additional high-quality randomized controlled trials to determine which oral hygiene interventions or combination of interventions are most effective in eliminating or reducing AGNB carriage.

An exploratory investigation using appreciative inquiry to promote nursing oral care

The purpose of this exploratory study was to determine the impact of an appreciative inquiry (AI) approach in a nursing knowledge translation initiative to facilitate oral care service delivery improvements. Comments made by nurse participants showed that they valued knowledge and strived for consistency in oral care provision. They felt that this could be obtained by implementing an oral health assessment tool, having access to an oral health expert, and enhancing interprofessional collaboration. Results also supported nurses' perceptions that organization-wide support and commitment is required in order to successfully implement and sustain improvements in oral care practice. AI was found to be a useful framework for generating dialogue regarding ways to improve oral care. This method generated positive momentum for practice change and empowered participants to become ambassadors for change, thereby effectively bridging the knowledge-to-action gap. Although AI is not a guaranteed solution for improving oral care in long-term care institutions, it should be considered as one part of a multi-interventional strategy.

Time-related increase of staphylococci, Enterobacteriaceae and yeasts in the oral cavities of comatose patients

BACKGROUND/PURPOSE

The composition of oral microbiota in comatose patients remains uncertain. Some pulmonary pathogens may be found in dental biofilms or as part of the saliva microbiota. It is supposed that some pneumopathogenic microorganisms may overgrow in the mouths of comatose patients and spread to their lungs.

METHODS

The oral colonization dynamics of staphylococci, Enterobacteriaceae and yeasts in nine comatose patients (group 1), and in 12 conscious patients that brushed their teeth at least twice a day (group 2) was evaluated. Both groups were followed up for 7 days after hospitalization. Daily samples of saliva were obtained, dispersed and plated on selective culture media and colony forming units of each microbial group were obtained.

RESULTS

For patients in group 1, the counts of total viable bacteria, staphylococci, Enterobacteriaceae and yeasts progressively increased in a time-dependant manner. For the conscious patients of group 2, there was no increase.

CONCLUSION

It would appear that concomitant consciousness and brushing teeth are determinants in controlling the selected pneumopathogen counts in resting saliva. The increase in microbial counts in comatose patients is understandable because these microorganisms could spread to the lungs.

Respiratory disease and the role of oral bacteria

The relationship between oral health and systemic conditions, including the association between poor oral hygiene, periodontal disease, and respiratory disease, has been increasingly debated over recent decades. A considerable number of hypotheses have sought to explain the possible role of oral bacteria in the pathogenesis of respiratory diseases, and some clinical and epidemiological studies have found results favoring such an association. This review discusses the effect of oral bacteria on respiratory disease, briefly introduces the putative biological mechanisms involved, and the main factors that could contribute to this relationship. It also describes the role of oral care for individuals who are vulnerable to respiratory infections.

Pneumonia in older people

The incidence of pneumonia is higher in older than younger people, due to both an increase in factors facilitating entry of infectious agents into the lungs, and attenuated functioning of the immune system. Classic features of presentation of pneumonia may be absent. The most common signs of pneumonia in old age are tachypnoea and tachycardia. Aetiology is established in only 50% of older patients. The empirical treatment of community-aquired pneumonia (CAP) should be aimed at its most common cause,Streptococcus pneumoniae. The empirical treatment of health care-associated pneumonia (HCAP) should be targeted at Gram-negative agents. Choice of antibiotic must include consideration of potential drug interactions.

Microbial interactions and differential protein expression in Staphylococcus aureus -Candida albicans dual-species biofilms

The fungal species Candida albicans and the bacterial species Staphylococcus aureus are responsible for a majority of hospital-acquired infections and often coinfect critically ill patients as complicating polymicrobial biofilms. To investigate biofilm structure during polymicrobial growth, dual-species biofilms were imaged with confocal scanning laser microscopy. Analyses revealed a unique biofilm architecture where S. aureus commonly associated with the hyphal elements of C. albicans. This physical interaction may provide staphylococci with an invasion strategy because candidal hyphae can penetrate through epithelial layers. To further understand the molecular mechanisms possibly responsible for previously demonstrated amplified virulence during coinfection, protein expression studies were undertaken. Differential in-gel electrophoresis identified a total of 27 proteins to be significantly differentially produced by these organisms during coculture biofilm growth. Among the upregulated staphylococcal proteins was l-lactate dehydrogenase 1, which confers resistance to host-derived oxidative stressors. Among the downregulated proteins was the global transcriptional repressor of virulence factors, CodY. These findings demonstrate that the hyphae-mediated enhanced pathogenesis of S. aureus may not only be due to physical interactions but can also be attributed to the differential regulation of specific virulence factors induced during polymicrobial growth. Further characterization of the intricate interaction between these pathogens at the molecular level is warranted, as it may aid in the design of novel therapeutic strategies aimed at combating fungal–bacterial polymicrobial infection.

Effects of mucosal care on oral pathogens in professional oral hygiene to the elderly

To elucidate the effects of mucosal care on colonization of mutans streptococci and infection of Candida species, we randomized 50 functionally dependent nursing home residents, mean age 76.1 (±7.8 years), 76% females, to receive oral professional care with or without mucosal care. During 12 months of follow-up, significant reduction in the numbers of mutans streptococci in saliva and dental plaque samples were observed in both treatment groups. However, there was no reduction in the numbers of mutans streptococci in tongue samples in the non-mucosal group (p=0.150). In the comparison between the treatment with and without mucosal care, the treatment with mucosal care showed a significant inhibition effects on numbers of nutans streptococci on the tongue surface at 6 months after the treatment as compared with the treatment without mucosal care (p=0.043). Mucosal care was not associated with any significant reduction in the rate of opportunistic infection with Candida species in any of the three sites. However, more subjects without mucosal care had Candida infection in dental plaque during the follow-up (p=0.046). Professional dental care with (versus without) mucosal care had no effect on mutans streptococci colonization in saliva or plaque. Lack of mucosal care seemed to be associated with higher rates opportunistic infections with Candida species.

Oral health care reduces the risk of postoperative surgical site infection in inpatients with oral squamous cell carcinoma

PURPOSE

Postoperative wound infection (WI) is a main complication after head and neck surgery. Poor oral health may be a risk factor for WI. We therefore assessed the contribution of oral health care in preventing postoperative WI in patients with oral squamous cell carcinoma (OSCC).

METHODS

A total of 66 consecutive inpatients with OSCC (mean age, 68 years) was divided into two groups that did or did not receive oral health care. There were no significant between group differences in gender, age, or T-, N-, or clinical stage. Patients in the care group were given oral health care plans by doctors of oral medicine, whereas patients in the control group were not. Twenty-three variables were recorded for each patient.

RESULTS

WI was observed in 14/66 patients (21%), three (3/33 = 9%) in the care group and 11 (11/33 = 33%) in the control group (p < 0.025). Univariate statistical analysis showed that 11 factors correlated with WI significantly: T-stage, clinical stage, wearing of dentures, tracheostomy, neck dissection, tissue transplantation, oral health care, preoperative radiation, blood transfusion, operation time, and blood loss. In multiple logistic regression analysis, only two factors were significant independent risk factors for WI: tissue transplantation (p = 0.01; odds ratio, 24.5) and lack of oral health care (p = 0.04; odds ratio, 6.0).

CONCLUSION

Oral health care may reduce the risk of postoperative WI in patients with OSCC.

Oral environmental factors affecting number of microbes in saliva of complete denture wearers

The purpose of this study was to clarify which oral environmental factors affected number of microbes in saliva in an edentulous environment. We enrolled 68 edentulous subjects in the study. Numbers of total anaerobic bacteria and Candida species in saliva were determined. Age, sex, un-stimulated salivary flow rate, pH and viscosity of saliva, histatin level in saliva, tongue coating status, tongue pressure, denture plaque status, material of denture base, duration of edentulism, frequency of self oral health care and number of cigarettes per day were also investigated as oral environmental factors. Correlation between number of total anaerobic bacteria or Candida species and each oral environmental factor was determined with the Spearman rank correlation coefficient. Stepwise logistic regression analysis was used to identify which factors were significantly associated with level of total anaerobic bacteria and Candida species. Correlation and stepwise logistic regression analyses revealed associations between un-stimulated salivary flow rate, tongue coating status, denture plaque status or frequency of self oral health care and number of total anaerobic bacteria. The correlation analysis showed a significant correlation between age and number of total anaerobic bacteria. Stepwise logistic analysis revealed associations between pH of saliva or viscosity of saliva and level of anaerobic bacteria; it also revealed associations between histatin level in saliva or un-stimulated salivary flow rate and level of Candida species. We conclude that salivary flow rate, in particular, affects number of salivary microbes in an edentulous environment.

[Swallowing disorders, pneumonia and respiratory tract infectious disease in the elderly]

Swallowing disorders (or dysphagia) are common in the elderly and their prevalence is often underestimated. They may result in serious complications including dehydration, malnutrition, airway obstruction, aspiration pneumonia (infectious process) or pneumonitis (chemical injury caused by the inhalation of sterile gastric contents). Moreover the repercussions of dysphagia are not only physical but also emotional and social, leading to depression, altered quality of life, and social isolation. While some changes in swallowing may be a natural result of aging, dysphagia in the elderly is mainly due to central nervous system diseases such as stroke, parkinsonism, dementia, medications, local oral and oesophageal factors. To be effective, management requires a multidisciplinary team approach and a careful assessment of the patient's oropharyngeal anatomy and physiology, medical and nutritional status, cognition, language and behaviour. Clinical evaluation can be completed by a videofluoroscopic study which enables observation of bolus movement and movements of the oral cavity, pharynx and larynx throughout the swallow. The treatment depends on the underlying cause, extent of dysphagia and prognosis. Various categories of treatment are available, including compensatory strategies (postural changes and dietary modification), direct or indirect therapy techniques (swallow manoeuvres, medication and surgical procedures).

Oral microbial and respiratory status of persons with mental retardation/intellectual and developmental disability: an observational cohort study

OBJECTIVE

The objective of this study was to determine the prevalence of select microorganisms in oral biofilms and to investigate relationships between oral and respiratory status in persons with mental retardation/intellectual and developmental disabilities (IDD).

STUDY DESIGN

We conducted a 6-month-long observational cohort study with 63 persons with IDD. Oral examinations, oral sampling, and medical record reviews were performed at baseline and then monthly. Polymerase chain reaction (PCR) was used to analyze all baseline oral samples for the presence of Streptococcus pneumoniae, Methicillin-resistant Staphylococcus aureus (MRSA), Prevotella melaninogenica, and Candida albicans. PCR analyses were also performed on participants' samples collected in the month before being diagnosed with a respiratory infection.

RESULTS

All subjects had P. melaninogenica detected by PCR in their oral samples. Fifty-five percent (35 of 63) of participants had S. pneumoniae, MRSA, and C. albicans in their oral samples at baseline. No dental decay was detected clinically, oral hygiene was fair, and dysphagia was common. During the 6 months of the study, there were 22 respiratory infections (35% of participants)-12 pneumonias, 7 sinusitis, 1 bronchitis, and 1 upper respiratory tract infection. Participants with microorganisms in their baseline samples were significantly more likely to develop any respiratory infection and those who had poor oral status were significantly more likely to develop pneumonia. Almost 60% of participants who developed respiratory infections had the same microorganism detected in the sample collected in the month before infection as had been detected in their baseline sample.

CONCLUSION

Potentially pathogenic microorganisms in the oral cavity and poor oral status significantly increased the risk of developing respiratory infections, including pneumonia, in persons with IDD. The results suggest that colonization with these microorganisms may persist despite routine tooth brushing. Meticulous comprehensive oral hygiene of the oral cavity may be needed to reduce oropharyngeal microbial load.

Role of pathogenic oral flora in postoperative pneumonia following brain surgery

BACKGROUND

Post-operative pulmonary infection often appears to result from aspiration of pathogens colonizing the oral cavity. It was hypothesized that impaired periodontal status and pathogenic oral bacteria significantly contribute to development of aspiration pneumonia following neurosurgical operations. Further, the prophylactic effects of a single dose preoperative cefazolin on the oral bacteria were investigated.

METHODS

A matched cohort of 18 patients without postoperative lung complications was compared to 5 patients who developed pneumonia within 48 hours after brain surgery. Patients waiting for elective operation of a single brain tumor underwent dental examination and saliva collection before surgery. Bacteria from saliva cultures were isolated and periodontal disease was scored according to type and severity. Patients received 15 mg/kg cefazolin intravenously at the beginning of surgery. Serum, saliva and bronchial secretion were collected promptly after the operation. The minimal inhibitory concentrations of cefazolin regarding the isolated bacteria were determined. The actual antibiotic concentrations in serum, saliva and bronchial secretion were measured by capillary electrophoresis upon completion of surgery. Bacteria were isolated again from the sputum of postoperative pneumonia patients.

RESULTS

The number and severity of coexisting periodontal diseases were significantly greater in patients with postoperative pneumonia in comparison to the control group (p = 0.031 and p = 0.002, respectively). The relative risk of developing postoperative pneumonia in high periodontal score patients was 3.5 greater than in patients who had low periodontal score (p < 0.0001). Cefazolin concentration in saliva and bronchial secretion remained below detectable levels in every patient.

CONCLUSION

Presence of multiple periodontal diseases and pathogenic bacteria in the saliva are important predisposing factors of postoperative aspiration pneumonia in patients after brain surgery. The low penetration rate of cefazolin into the saliva indicates that its prophylactic administration may not be sufficient to prevent postoperative aspiration pneumonia. Our study suggests that dental examination may be warranted in order to identify patients at high risk of developing postoperative respiratory infections.