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At least 631 records · Page 35Linked to original sources
PubMed2006

Oral decontamination with chlorhexidine reduces the incidence of ventilator-associated pneumonia.

RATIONALE: Ventilator-associated pneumonia (VAP) is the most frequently occurring nosocomial infection associated with increased morbidity and mortality. Although oral decontamination with antibiotics reduces incidences of VAP, it is not recommended because of potential selection of antibiotic-resistant pathogens. We hypothesized that oral decontamination with either chlorhexidine (CHX, 2%) or CHX/colistin (CHX/COL, 2%/2%) would reduce and postpone development of VAP, and oral and endotracheal colonization. OBJECTIVES: To determine the effect of oral decontamination with CHX or CHX/COL on VAP incidence and time to development of VAP. METHODS: Consecutive patients needing mechanical ventilation for 48 h or more were enrolled in a randomized, double-blind, placebo-controlled trial with three arms: CHX, CHX/COL, and placebo (PLAC). Trial medication was applied every 6 h into the buccal cavity. Oropharyngeal swabs were obtained daily and quantitatively analyzed for gram-positive and gram-negative microorganisms. Endotracheal colonization was monitored twice weekly. RESULTS: Of 385 patients included, 130 received PLAC, 127 CHX and 128 CHX/COL. Baseline characteristics were comparable. The daily risk of VAP was reduced in both treatment groups compared with PLAC: 65% (hazard ratio [HR]=0.352; 95% confidence interval [CI], 0.160, 0. 791; p=0.012) for CHX and 55% (HR=0.454; 95% CI, 0.224, 0. 925; p=0.030) for CHX/COL. CHX/COL provided significant reduction in oropharyngeal colonization with both gram-negative and gram-positive microorganisms, whereas CHX mostly affected gram-positive microorganisms. Endotracheal colonization was reduced for CHX/COL patients and to a lesser extent for CHX patients. No differences in duration of mechanical ventilation, intensive care unit stay, or intensive care unit survival could be demonstrated. CONCLUSIONS: Topical oral decontamination with CHX or CHX/COL reduces the incidence of VAP.

Administration, Topical↗
PubMed2001

Persistent presence of Bacteroides forsythus as a risk factor for attachment loss in a population with low prevalence and severity of adult periodontitis.

BACKGROUND: Previous longitudinal studies investigating the role of microorganisms in periodontitis have focused on subjects with a high prevalence and severity of disease. The complex profile of microbial species in severe cases of periodontitis might not allow us to differentiate which bacterial species initiate disease or which species simply proliferate after disease progression. This prospective longitudinal study followed a group of 205 subjects who showed a low prevalence and severity of adult periodontitis, and thus allowed us to monitor early microbiological changes in the development of periodontitis. METHODS: Subgingival plaque was collected from proximal surfaces of a posterior sextant at 6-month intervals for 2 years. During the monitoring period, 44 subjects had either attachment loss or attachment gain. Using multiplex polymerase chain reaction (PCR), all plaque samples from those 44 subjects were analyzed for the presence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Porphyromonas gingivalis. RESULTS: Both subjects with attachment loss and those with attachment gain had a high prevalence of these 3 periodontal pathogens. The mere presence of any of the 3 species at a site could not predict future attachment loss at that specific site. However, subjects with a persistent presence of B. forsythus at any site across all visits had 5.3 times higher odds of having at least one site in their mouth losing attachment compared to subjects with occasional or no presence of B. forsythus. CONCLUSIONS: The persistence of B. forsythus identified subjects at higher risk, but not which specific sites in those subjects would lose attachment.

Actinobacillus Infections↗
PubMed1989

The oral cavity as a port of entry for early infections in patients treated with bone marrow transplantation.

Before treatment of 181 patients with bone marrow transplantation (BMT) for leukemia, severe aplastic anemia, or metabolic disorders, the oral condition was examined clinically and roentgenologically. Fifty-three patients (29%) had chronic dental infections (osteitis) that needed treatment before BMT. In 10 of 181 cases (6%), BMT was postponed because of oral infections. Septicemia during the neutropenic phase was caused by oral microorganisms (alpha streptococci) in 24 of 59 (41%) patients with microbiologically proven septicemia. Septicemia with alpha streptococci was associated with graft-versus-host disease prophylaxis with methotrexate and subsequent increased frequency of oral ulcerations. No difference was observed in the frequency of reactivation of latent herpes simplex virus infection between different graft-versus-host disease prophylaxis regimens. Reactivation was more frequent in patients conditioned with total body irradiation than in patients conditioned without total body irradiation. Antiviral prophylaxis, with subsequent decreased frequency of oral herpes simplex reactivation, appeared to contribute to a low frequency of septicemia with alpha streptococci.

Adolescent↗
PubMed1981

Adherence of Acinetobacter calcoaceticus RAG-1 to human epithelial cells and to hexadecane.

The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investigated and compared with its ability to adhere to a test hydrocarbon (hexadecane). RAG-1, a microorganism originally isolated for growth on hydrocarbon, adhered to epithelial cells when grown under conditions which promote its adherence to hexadecane; similarly, RAG-1 cells adhered poorly to epithelial cells when grown under conditions which cause the cells to possess low affinity towards hexadecane. A mutant derived from RAG-1, MR-481, deficient in its ability to adhere to hydrocarbon, was similarly unable to adhere to epithelial cells. RAG-1 adherence to epithelial cells was not blocked by a number of sugars tested. Streptococcus pyogenes, whose adherence to epithelial cells has been previously attributed to hydrophobic interactions, was also able to adhere to hexadecane. Results suggest that hydrophobic interactions mediate adherence of the strains studied to both epithelial cells and hydrocarbon.

Acinetobacter↗
PubMed1999

The influence of luting cements on the fermentation of sucrose by oral microorganisms.

OBJECTIVES: Three luting cements based on zinc oxide phosphate, glass ionomer or composite resin were compared with respect to their influence on the anaerobic fermentation of sucrose by human oral bacteria. METHODS: Fifteen standardized samples of each of the three luting cements were prepared according to the manufacturer's instructions and stored for 72 h at 37 degrees C in distilled water, which was also used as elution medium. After removing the samples solutions were incubated with human fasting saliva, sucrose and a bicarbonate buffer in a Warburg apparatus. Intermediary organic acids resulting from anaerobic fermentation of sucrose were quantified indirectly by manometric measurement of CO2, released from the buffer. RESULTS: The materials did not indicate either an accelerating or an inhibiting effect on the formation of organic acids from sucrose. CONCLUSION: In the case of bacterial microleakage along the interface between cavity and luting cement, an inhibition of acid induced dentin or enamel demineralisation--using the materials investigated--cannot be expected.

Analysis of Variance↗
PubMed1998

Toxicological aspects on the release and systemic uptake of mercury from dental amalgam.

This paper summarizes some recent reports on mercury release from amalgam fillings and resulting concentrations in biological fluids, development of antibiotic resistance, and kidney function. In a series of studies of subjects with amalgam fillings, mercury (Hg) levels were followed in saliva, feces, blood, plasma, and urine before and until 60 d after removal of all of the fillings. The Hg concentrations in saliva remained elevated for at least 1 wk, suggesting that dissolved Hg vapor is not the major source of mercury in mixed saliva. An absorption phase of Hg was seen in plasma during 24 h after amalgam removal. After 60 d the plasma Hg concentration was reduced to 40%, of the baseline level. The decrease per amalgam surface was 0.11 nmol/l (range 0.02 0.40). The Hg level in feces increased two orders of magnitude two days after amalgam removal. At day 60, the median Hg concentration was still slightly higher than the median value of the amalgam free control group. The resistance patterns of the oral and intestinal microflora in these subjects were also studied. In the intestinal microflora, the relative amount of intestinal microorganisms resistant to 50 microM HgCl2 peaked 7 d after removal of the amalgam fillings, with a median value per sample of 6.1%, compared to 1.3% in samples collected prior to the Hg exposure. However, no statistical differences in the resistance pattern of the oral microflora were detected between the control and the experimental groups. A number of sensitive kidney function parameters were measured 1 wk before and 1, 2, and 60 d after amalgam removal. No effects on the various kidney parameters studied were recorded. According to the conclusions of independent evaluations from different state health agencies, the release of mercury from dental amalgam does not present any non-acceptable risk to the general population.

Absorption↗
PubMed1990

Anterior open bite and gingival recession in children and adolescents.

Gingival recession is a manifestation of periodontal breakdown. Plaque microorganisms are the primary aetiological factor, but other secondary conditions are also associated with its presence. This study examined the hypothesis that localized gingival recession is more prevalent in open-bite cases. The study included 26 children with untreated anterior open bite and a matched control group. Clinical crown length, recession depth, oral habits and periodontal indices were recorded for each individual. Although the plaque index was not significantly different between the two groups, the open-bite group showed significantly greater clinical crown length and gingival inflammation. This may be attributed to increased virulence of dehydrated plaque and it is suggested that open bite may predispose to the development of localized gingival recession in the anterior segments of young individuals.

Adolescent↗
PubMed1992

Recurrent vaginal candidiasis. Results of a cohort study of sexual transmission and intestinal reservoir.

Yeast cultures from the oral cavity, vagina and rectum were obtained from 125 women experiencing an acute episode of recurrent candidal vaginitis. To investigate the role of sexual transmission, oral, penile and ejaculate cultures were also prepared from all the male sexual partners. The rates of oral and rectal Candida species colonization in the women were 36% (45/125) and 44.8% (56/125), respectively. The male partners' oral cavities were positive in 23.2% (29/125) and the penile coronal sulcus and seminal fluid in 16% (20/125) and 14.4% (18/125), respectively. The susceptibility of the isolated species to the main antimycotic drugs was ascertained with the agar diffusion method. Therapy in the women and the colonized sexual partners was carried out, eliminating the microorganism from every positive site. Control cultures were obtained two weeks after the completion of therapy, and follow-up was continued for one year. The overall clinical and microbiologic cure rate in the study group was 72% (95/125). The rate of relapse was not influenced by the treatment of Candida colonization of the female intestinal tract. The recurrence rate after treatment in the couples in which the man harbored yeast (oral cavity, penile coronal sulcus, seminal fluid) was lower (15.8% vs. 44.8%, P = .0019) than that recorded in the couples without sexual partner involvement. The identification and treatment of the male sexual partner's Candida colonization seems important in the prevention of recurrent vulvovaginitis.

Antifungal Agents↗
PubMed2002

Influence of combined intravenous and topical antibiotic prophylaxis on the incidence of infections, organ dysfunctions, and mortality in critically ill surgical patients: a prospective, stratified, randomized, double-blind, placebo-controlled clinical trial.

We prospectively studied the impact of an antibiotic prophylaxis regimen on the incidence of infections, organ dysfunctions, and mortality in a predominantly surgical and trauma intensive care unit (ICU) population. A total of 546 patients were enrolled and stratified according to Acute Physiology and Chronic Health Evaluation (APACHE)-II scores. They were then randomized to receive either 2 x 400 mg of intravenous ciprofloxacin for 4 days, together with a mixture of topical gentamicin and polymyxin applied to the nostrils, mouth, and stomach throughout their ICU stay or to receive intravenous and topical placebo. When receiving prophylaxis, significantly fewer patients acquired infections (p = 0.001, risk ratio [RR], 0.477; 95% confidence interval [CI], 0.367-0.620), especially pneumonias (6 versus 29, p = 0.007), other lower respiratory tract infections (39 versus 70, p = 0.007), bloodstream infections (14 versus 36, p = 0.007), or urinary tract infections (36 versus 60, p = 0.042). Also, significantly fewer patients acquired severe organ dysfunctions (63 versus 96 patients, p = 0.0051; RR, 0.636; 95% CI, 0.463-0.874), especially renal dysfunctions (17 versus 38; p = 0.018). Within 5 days after admission, 24 patients died in each group, whereas 28 patients receiving prophylaxis and 51 receiving placebo died in the ICU thereafter (p = 0.0589; RR, 0.640; 95% CI, 0.402-1.017). The overall ICU mortality was not statistically different (52 versus 75 fatalities), but the mortality was significantly reduced for 237 patients of the midrange stratum with APACHE-II scores of 20-29 on admission (20 versus 38 fatalities, p = 0.0147; RR, 0.508; 95% CI, 0.295-0.875); there was still a favorable trend after 1 year (51 versus 60 fatalities; p = 0.0844; RR, 0.720; 95% CI, 0.496-1.046). Surveillance cultures from tracheobronchial, oropharyngeal, and gastric secretions and from rectal swabs did not show any evidence for the selection of resistant microorganisms in the patients receiving prophylaxis.

APACHE↗
PubMed2006

Microbiological diagnostics in oral diseases.

Most infections of the oral cavity, including the major dental diseases caries and periodontitis, are opportunistic in nature. They are caused or maintained by microorganisms of the resident or transient flora normally present in low numbers and not pathogenic, but in certain circumstances develop infections. Mucosal infections have some degree of specificity [e.g. Candida spp., Staphylococcus aureus, and enterics] and a microbiological test can be interpreted accurately for clinical diagnosis and choice of treatment. Subepithelial or deep infections, however, include a number of species from the resident flora, mainly anaerobes whose role in the infections is difficult to interpret. However, microbiological tests and the presence of certain bacterial species could be used for treatment control, risk-evaluation and even for patient motivation in the prevention of these diseases. Microbiological diagnosis can be used in general practice for several purposes and in various situations that can be of great value for the dental patient.

Bacteria↗
PubMed2000

Capacity of denture plaque/biofilm removal and antimicrobial action of a new denture paste.

The efficacy of a paste for complete dentures was analyzed in terms of denture plaque/biofilm removal and antimicrobial action against specific microorganisms by determination of colony forming units of mutans group streptococci and yeast from 120 full denture wearers with a healthy palatine mucosa. The patients were given a questionnaire to evaluate the experimental product in terms of important characteristics. The paste was widely accepted by the patients, and effective in denture plaque removal and antimicrobial action. The species of yeasts most frequently isolated were C. albicans, C. tropicalis and C. glabrata. We conclude that it is possible for complete denture wearers to keep their dentures clean with the regular use of a paste-like hygienic product.

Aged↗
PubMed1983

[Microorganisms in home-care inhalation devices].

Contamination of inhalation equipment used at home, cleaning procedures, and the occurrence of potentially pathogenic micro-organisms in mouthwash water was studied in 55 patients. Fungi in the oropharyngeal space were found in 58%, Staphylococcus aureus in 29%, Enterobacteriaceae in 47% and Pseudomonas aeruginosa in 11%. Contamination with potentially pathogenic micro-organisms occurred in 64% of inhalation equipment and inhalation solutions. In a total of 151 samples from the equipment Klebsiella was present in 14%, Enterobacter in 10%, Serratia and Acinetobacter in 11% each, Pseudomonas in 5% and Staphylococcus aureus in 4.5%. In three cases the same serotype of Ps. aeruginosa was present in the oropharyngeal cavity and inhalation equipment. In most cases the cleansing of the inhalation equipment had been inadequate. Only 36% of those questioned cleaned the equipment immediately before use, only 4 of 20 stated that they washed their hands before use. Subjective assessment of the value of inhalation treatment was either "very good" or "good" in 80%.

Aerosols↗
PubMedDate not supplied

Pediatric bone marrow transplantation: oral complications and recommendations for care.

Bone marrow transplantation (BMT) has become an increasingly common treatment option for those patients who have a disease that affects the bone marrow (BM) directly or indirectly. Because of the level of immunosuppression achieved in BMT, any problems the pediatric patient presents in the oral cavity can become life-threatening and increase the length of hospital stay, the patient's discomfort, and the treatment costs. The oral cavity is a reservoir for microorganisms thus by reducing their number through optimal care, immunosuppressed patients may decrease their chance of a life-threatening systemic infection from an oral source. Many BMT teams believe that toothbrushing increases the risk of bacteremia and bleeding; however, problems are more likely to arise when patients are not compliant with good oral hygiene habits. It is vital to educate the caretaker and the child about the importance of oral care in order to minimize discomfort and maximize the chances for a successful transplant. This paper discusses the important and unique role that pediatric dentistry has in the multiprofessional BMT team to help bring about a successful outcome through the prevention and treatment of the acute oral complications often seen in these patients.

Bacteremia↗
PubMed2002

Survey of dental hygienists and healthcare workers for microorganisms in the oral cavity.

Over 350 bacterial species are known to form communities on tooth surfaces in the oral cavity, and opportunistic pathogens are frequently isolated from samples taken from the oral cavities of immunocompromised hosts, as well as elderly people with poor oral hygiene. To confirm the correlation between the prevalence of opportunistic pathogens in the oral cavity and oral hygiene, dental plaque and saliva samples from 15 dental hygienists and 15 healthcare workers were investigated. No opportunistic pathogens were found in the samples from dental hygienists, however, they were isolated from 10 of the 15 healthcare workers (66.7%). The total amounts of Streptococcus sp. and Lactobacillus sp. were also significantly higher in the healthcare workers. The amount of Streptococcus mutans was also higher, although the difference was not significant. From our results, we concluded that the prevalence of opportunistic pathogens and cariogenic bacteria in the oral cavity may be reduced by proper oral hygiene measures.

Adult↗
PubMed2002

Buccoadhesive erodible disk for treatment of oro-dental infections: design and characterisation.

Buccoadhesive erodible disks of cetylpyridinium chloride were prepared using different bioadhesive polymers along with excipients like mannitol. The purpose of designing the erodible disk was to obviate the need for removal of exhausted device. The optimized disk containing 5.0 mg of cetylpyridinium chloride, 2.0 mg of magnesium stearate and 6.0 mg of mannitol along with sodium carboxy methyl cellulose DVP and hydroxypropylmethylcellulose K4M in the ratio of 1:3 was found to release the drug for a period of over 6.0 h without getting dislodged. Maximum in vitro drug release was found to be 94.78% in 6.0-h study. In situ release characteristics were evaluated using a 'flow-through assembly', which simulated the conditions of the human buccal cavity. The drug concentrations in the in situ samples were found to be above minimum inhibitory concentration (MIC) of the drug. The bioadhesive performance and the surface pH of the disks were satisfactory. Cetylpyridinium chloride disks were tested against microorganisms commonly found in oro-dental infections namely Candida albicans, Staphylococcus aureus, Escherichia coli and Streptococcus mutans. The disk as well as the in situ samples showed inhibition of growth of microorganisms. Approval was taken from Jamia Hamdard Review Board (Ethical Board) to perform in vivo studies in healthy human volunteers. In vivo evaluation of buccoadhesive disks revealed adequate comfort, taste, and non-irritation and none of the volunteers reported severe dry mouth/severe salivation or heaviness at the place of attachment. Salivary concentrations were maintained above MIC for 8.0 h. Correlation was found between the drug concentration in situ and concentration of drug in saliva collected in healthy human volunteers. The correlation was found to be positive with a correlation coefficient of 0.9596. It was found to be statistically significant at 5% confidence level (P<0.05).

Adhesives↗
PubMed2005

Antimicrobial activity of Croton cajucara Benth linalool-rich essential oil on artificial biofilms and planktonic microorganisms.

We have previously demonstrated that a linalool-rich essential oil from Croton cajucara Benth presents leishmanicidal activity. In the present study, we demonstrate that this essential oil inhibits the growth of reference samples of Candida albicans, Lactobacillus casei, Staphylococcus aureus, Streptococcus sobrinus, Porphyromonas gingivalis and Streptococcus mutans cell suspensions, all of them associated with oral cavity disease. The purified linalool fraction was only inhibitory for C. albicans. Microbes of saliva specimens from human individuals with fixed orthodontic appliances, as well as the reference strains, were used to construct an artificial biofilm which was exposed to linalool or to the essential oil. As in microbial suspensions, the essential oil was toxic for all the microorganisms, while the purified linalool fraction mainly inhibited the growth of C. albicans. The compounds of the essential oil were separated by thin layer chromatography and exposed to the above-cited microorganisms. In this analysis, the proliferation of the bacterial cells was inhibited by still uncharacterized molecules, and linalool was confirmed as the antifungal component of the essential oil. The effects of linalool on the cell biology of C. albicans were evaluated by electron microscopy, which showed that linalool induced a reduction in cell size and abnormal germination. Neither the crude essential oil nor the purified linalool fraction is toxic to mammalian cells, which suggests that the essential oil or its purified components may be useful to control the microbial population in patients with fixed orthodontic appliances.

Acyclic Monoterpenes↗
PubMed1992

Inhibition of microbial adherence by sphinganine.

Sphingosines (precursors and degeneration products of complex sphingolipids) are mediators in membrane second-messenger cascades and in a wide variety of functions in eukaryotic cells. Sphingosines are also lethal for gram-positive microorganisms. In addition to its direct effect, sphinganine is here reported to affect the adherence of Streptococcus mitis to buccal epithelial cells and of Staphylococcus aureus to nasal mucosal cells after incubation for 90 min at 37 degrees C. When the bacteria were pretreated with 8.1, 16.2, 32.5, or (for Strep. mitis) 65 microM sphinganine for 60 min at 37 degrees C, adherence counts were reduced for Staph. aureus by 27, 37, and 60% and for Strep. mitis by 19, 44, 54, and 73%, respectively (p < 0.001). In contrast, pretreatment of buccal cells with 81.2 microM lipid increased adherence by 14% (p < 0.01), but no change occurred at either 16.2 or 325 microM lipid. These results further demonstrate the double-edged ability of sphingosines to regulate cellular activities and their potential as multifunctional therapeutic agents for infectious diseases.

Bacterial Adhesion↗
PubMed1995

The biochemical milieu of the host in the selection of anaerobic species in the oral cavity.

The periodontal pocket provides a unique structural site for studies on host/bacterial interactions. The pocket is colonized by a complex but characteristic anaerobic bacterial flora. Many new taxa have been described that have now been supported by comparative rRNA sequence analysis. Within recent years, several molecular approaches have been used to describe both cultivable and noncultivable species, and new genotypes have been reported. Microbial activity rather than the mere presence of a microorganism at a site must be a major factor in the process of disease development. Information on metabolic activities of species and identification of substrates are therefore essential to elucidate the complex interactions that are likely to occur in vivo. We have been using a variety of analytical procedures such as 13C substrate-enrichment nuclear magnetic resonance, 14C isotopic labeling experiments, enzyme assays, impedance measurements, and various chromatographic and electrophoretic procedures to study key species of this predominantly asaccharolytic flora. Results have so far indicated a major role for cationic and anionic acids as sources of energy, but the mechanisms of substrate processing may differ significantly between species. In this ecosystem, crevicular fluid is the likely source of nutrients for species. Components of this fluid appear to have a role in the selection of species in subgingival sites.

Amino Acids↗