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At least 541 records · Page 30Linked to original sources
PubMed1999

Microbiotica associated with refractory periodontis. Prevalence and antibiotic susceptibility.

BACKGROUND: The aim of the present study was to analyze the composition of subgingival microflora in patients with refractory periodontitis and to evaluate the antimicrobial sensitivity of isolated periodontopathic microorganisms to different antibiotics. METHODS: Eleven subjects with a mean age of 46.4 years were selected for the present study. All had been treated for periodontal disease in the past. After further disease progression patients were included in this study. Eight subgingival plaque samples per patients were collected for cultural analysis. RESULTS: "Black pigmenting anaerobic bacilli" were the pathogenic microorganisms more frequently isolated. The findings from antibiotic susceptibility test showed that high number of bacteria associated with refractory periodontitis resulted resistant to erythromycin, metronidazole and tetracycline. The most effective antibiotics were ciprofloxacin, amoxicillin-metronidazole and amoxicillin-clavulanic acid. CONCLUSIONS: Microbiological analysis and antibiotic susceptibility test should be considered important tools in the management of patients with poor clinical response to conventional periodontal treatment.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Ex-vivo study of the capacity of bacteria of the genus Capnocytophaga to adhere to human buccal epithelial cells].

The bacteria of the genre Capnocytophaga are part of the subdominant flora of the oral cavity. For diverse microorganisms it has been proved that the adhesion constitutes the first step of the colonization of a place leading to the eventual pathology. The adhesion capacity to human epithelial cells (keratinised and non) of eight strains of genus Capnocytophaga has been studied. All strains appear to have a very weak capacity of adhesion. This diministe can be originated from the fact that the host cells have been harvested from healthy subjects.

Bacterial Adhesion↗
PubMed1996

Purification of NADH: hypothiocyanite oxidoreductase in Streptococcus sanguis.

NADH: hypothiocyanite oxidoreductase (NHOR) activity, found in some oral Streptococci, is postulated to protect these microorganisms against salivary peroxidase-produced hypothiocyanite. NHOR, however, has not been purified so far. The purification of NHOR from crude extracts of Streptococcus sanguis NCTC 7863 strain (by ultrafiltration and anion-exchange chromatography) revealed one fraction of 125 +/- kDa. However, SDS-PAGE electrophoresis provided a single protein of 21.1 +/- 1.2 kDa. This last discovery suggests that NHOR enzyme is a hexameric complex having six subunits.

Chromatography, Gel↗
PubMed1990

[The bacteriology of normal wound healing following tooth extraction with special reference to anaerobic microorganism diagnosis].

In 10 patients with indication to tooth extraction swaps from the microbiotopes "sulcus/gingival pocket", "root canal", "socket" and "extraction wound 2 and 7 days after extraction" were investigated bacteriologically. The anaerobic-aerobic mixed flora with predominance of anaerobes verified in the microbiotopes "sulcus/gingival pocket", "socket" and "extraction wound 2 days after extraction" was identically. The flora of the root canal was distinguished by a smaller amount of microbes with predominance of aerobes. In the 7 days old extraction wound only single aerobes could be verified whereas anaerobes were missed totally.

Alveolar Process↗
PubMed1978

[Metabolism of the sugar substitute xylite by microorganisms of the human oral cavity].

With the help of thin layer chromatography, human saliva was examined after varying lengths of incubation time of radioactively labelled xylitol to determine whether bacteria of the human oral cavity are able to use this sugar substitute. This showed that different activities occur in saliva which either complete the breakdown within a few hours or require more than 24 hours incubation. Induction of the enzymes for xylitol and sorbitol breakdown was observed during incubation, which led to a speeding up of metabolism. A comparison with sorbitol revealed that xylitol is metabolised considerably more slowly than sorbitol.

Bacteria↗
PubMed1996

Caries-related salivary microorganisms and salivary flow rate in bone marrow recipients.

Cancer treatments often induce oral complications. In this study we investigate longitudinally the salivary gland function, the salivary caries-related microorganisms, and buffer capacity in bone marrow recipients. Stimulated saliva samples were taken midmorning. The salivary factors were studied in 42 patients from before transplant until 4 months after transplant. A dramatic reduction (66%) of salivary flow rate is noticed in all patients at 1 month after transplant, and only a partial recovery (42% reduction) is seen after 4 months. A clear shift toward a lower buffer capacity and a higher amount of cariogenic microorganisms is seen posttransplant. This shift is more pronounced when total body irradiation was included in the pretransplant conditioning therapy. These findings indicate that the studied parameters in transplant recipients can contribute to a higher caries risk and oral complications during the early posttransplant period.

Adolescent↗
PubMed1998

[Benign maxillofacial mucormycosis. Report of a case and review of the literature].

Mucormycosis is a rare and often lethal infection caused by an opportunistic fungus of the Phycomycetes class. This microorganism is a saprophytic aerobial fungus common in nature and in oral mucosae, nose, paranasal sinus and throat. Mucormycosis has been described in various clinical forms: rhinocerebral, pulmonary, systemic, cerebral and cutaneous, always in immunodepressed patients, with rapid evolution and high rate of mortality. However, rare cases involving maxillofacial area are described in healthy patients with benign evolution and good prognosis as in a case observed at the Department of Maxillofacial Surgery of the University of Naples "Federico II".

Adult↗
PubMed1992

Effect of 4 days of mouth rinsing with delmopinol or chlorhexidine on the vitality of plaque bacteria.

Delmopinol is a new surface active anti-plaque agent that has demonstrated a low antimicrobial effect in vitro. By use of a vitality staining technique, the antimicrobial effect on bacteria in plaque samples was tested after rinsing with delmopinol or chlorhexidine. 6 healthy male subjects volunteered to rinse for 4 days using a double-blind cross-over study design with a wash-out period between the rinsing regimens. No oral hygiene measures were allowed during the test periods and each test period started with a professional tooth cleaning procedure 2 days before the start of rinsing to allow for plaque formation. Rinsing was performed with 0.2% delmopinol hydrochloride or 0.2% chlorhexidine digluconate 2 x a day. Small samples of plaque were collected from the buccal surfaces of premolars and 1st molars before the first rinse on day 1 and then before and 1, 2, 4, 7, and 24 h after the last rinse on the 4th day. The plaque samples were immediately stained with propidium iodide and fluorescein diacetate to visualize dead and vital microorganisms respectively. The vitality of the microflora was evaluated using a fluorescence microscope. The baseline vitality values were 91% for chlorhexidine and 86% for delmopinol. At day 4, the plaque vitality for chlorhexidine was approximately 40% up to 4 h and 50% at 7 h and 60% at 24 h after the last rinse. Corresponding values for plaque vitality after delmopinol rinsing were between 70 and 80% on all sampling occasions.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗
PubMed1999

Adhesion and surface-aggregation of Candida albicans from saliva on acrylic surfaces with adhering bacteria as studied in a parallel plate flow chamber.

Adhesive interactions between Candida albicans and oral bacteria are generally thought to play a crucial role in the microbial colonization of denture acrylic, which may lead to denture stomatitis. This study investigated the influence of saliva on the adhesive interactions between C. albicans and Streptococcus sanguis or Actinomyces naeslundii on denture acrylic. First, bacteria were allowed to adhere to the acrylic surface from a flowing suspension, and subsequently yeasts were flowed over the acrylic surface. The organisms were assayed in the presence or absence of human whole saliva. All experiments were carried out in a parallel plate flow chamber and enumeration was done in situ with an image analysis system. In the absence of adhering bacteria, adhesion of C. albicans from buffer was more extensive than from saliva. However, in the presence of adhering bacteria, yeast adhesion from saliva was increased with respect to adhesion of yeasts from buffer, indicating that specific salivary components constitute a bridge between bacteria and yeasts. In all cases, yeast aggregates consisting of 3 to 5 yeast cells were observed adhering to the surface. A surface physico-chemical analysis of the microbial cell surfaces prior to and after bathing the microorganisms in saliva, suggests that this bridging is mediated by acid-base interactions since all strains show a major increase in electron-donating surface free energy parameters upon bathing in saliva, with no change in their zeta potentials. The surface physico-chemical analysis furthermore suggests that S. sanguis and A. naeslundii may use a different mechanism for adhesive interactions with C. albicans in saliva.

Acrylic Resins↗
PubMed1996

[Primary tuberculosis of the oral cavity].

Primary tuberculosis in the oral cavity is a rare entity. Usually, the microorganisms need a disruption of the oral mucosa to become pathogenic. In this article the authors describe a clinical case of primary oral tuberculosis, on a female of 52 years-old who suffered an exodontia 20 days before. The bacteria identificated was Mycobacterium tuberculosis hominis. The microbiologic identification is essential to assure the efficacy of the treatment.

Antibiotics, Antitubercular↗
PubMed2003

Antibiotic resistance.

Through billions of years of evolution, microbes have developed myriad defense mechanisms designed to ensure their survival. This protection is readily transferred to their fellow life forms via transposable elements. Despite very early warnings, humans have chosen to abuse the gift of antibiotics and have created a situation where all microorganisms are resistant to some antibiotics and some microorganisms are resistant to all antibiotics. When antibiotics are used, six events may occur with only one being beneficial: when the antibiotic aids the host defenses to gain control and eliminate the infection. Alternatively, the antibiotic may cause toxicity or allergy, initiate a superinfection with resistant bacteria, promote microbial chromosomal mutations to resistance, encourage resistance gene transfer to susceptible species, or promote the expression of dormant resistance genes.

Anti-Bacterial Agents↗
PubMed2000

Determination of the salivary retention of hexetidine in-vivo by high-performance liquid chromatography.

The non-antibiotic antimicrobial agent hexetidine is widely used at a concentration of 0.1% w/v as an oral rinse to reduce the number of viable microorganisms within the oral cavity. However, following use, the available concentration of hexetidine in the oral cavity declines with time, thus compromising the resultant antimicrobial activity. It is, therefore, desirable to determine the persistence of the agent in the oral cavity by quantification of the drug concentration in saliva, thus enabling prediction of its antimicrobial activity in the oral environment. A rapid reverse-phase HPLC method was therefore developed and validated for hexetidine in aqueous solution (Oraldene) and in saliva samples collected from volunteers post-rinsing with 15 mL of hexetidine oral rinse for 30s. The HPLC assay was sufficiently sensitive to accurately detect hexetidine in saliva up to 25 min after in-vivo use of a commercial oral rinse. Furthermore, it was possible to detect hexetidine below the published minimum inhibitory concentrations (MICs) for a selection of microorganisms. From these data a first-order elimination rate constant of hexetidine from the oral cavity was determined post-rinsing in each of six volunteers. The validated HPLC assay method presented is useful for the assay of hexetidine in the oral cavity both at and below MICs. The first-order elimination rate constant shows significant variation between volunteers.

Adult↗
PubMed1997

Oral scurvy and periodontal disease.

Although gingival bleeding is a manifestation of both scurvy and inflammatory periodontal disease, the two conditions are distinctly separate entities. The defective collagen synthesis associated with scurvy also manifests many of the same symptoms as deficient vitamin C physiology, but neither condition is associated with periodontal disease. Unlike scurvy, the various periodontal diseases are caused by oral plaque microorganisms. The body's reaction to these microorganisms is strongly influenced by the compromised functioning of leucocytes and monocytes. Although certain infections and systemic diseases cause gingival bleeding, avitaminosis-C does not cause commonly encountered periodontitis. Vitamin C should not be used for the prophylaxis or cure of periodontal disease in otherwise healthy, well-nourished individuals. A patient with bleeding gingivae warrants referral to a periodontist, oral medicine specialist, or appropriately qualified dentist for examination and treatment.

Ascorbic Acid↗
PubMed1981

Fluoride accumulation by oral microorganisms.

Ten laboratory strains of oral microorganisms and 17 recent clinical isolates were examined for their ability to concentrate fluoride from a 1 ppm (0.05 mM NaF( fluoride solution. The laboratory strains concentrated the ion from two- to six-fold over the surrounding media. Clinical isolates of Actinomyces concentrated the ion to similar levels to the laboratory strains of this organism; however, clinical isolates of Streptococcus mutans and S. sanguis concentrated the fluoride significantly less than any of the laboratory strains examined.

Actinomyces↗
PubMed2006

[The role of the oral flora in the pathogenesis of aspiration pneumonia].

The bacterial pneumonia is one of the most frequent complications leading to death among hospitalized patients. The morbidity and mortality of pneumonia is extremely high in the intensive care units and in chronic nursing stations, especially in institutes dealing with old patients. The most common form of lung infection is the aspiration pneumonia. Periodontal diseases play an evident role in the etiology of aspiration pneumonia due to their effect to alter the oral bacterial flora. Authors review the significance of pathogen microorganisms originating from the oral cavity in the development of bacterial pneumonia. The extent of the affected population is discussed and the importance of their oral hygiene and bacterial flora is also specified. The bacterial, enzymatic and molecular pathomechanisms leading to aspiration pneumonia are described, and high risk populations and treatment types are determined. The possibilities of prevention methods for aspiration pneumonia are fully explained and recent directions of actual researches and proposals to minimize the incidence of this disease are summarized.

Humans↗
PubMed1996

Adherence of oral microorganisms to human parotid salivary proteins.

Bacterial colonisation of oral surfaces by microorganisms may be dependent on their interaction with specific host receptor molecules. Primary oral colonisers are known to remove specific proteins from parotid saliva. The aim of this study was to determine whether these interactions facilitate microbial attachment to a surface and hence identify specific salivary components as putative host receptor molecules. Parotid saliva was resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and then electroblotted onto nitrocellulose membranes. Suspensions of fluorescently labelled microorganisms were incubated with the blots and salivary components with adherent bacteria identified as fluorescent bands under ultraviolet (UV) transillumination. Species of streptococci known to be early colonisers of the clean tooth surface were found to adhere specifically to certain salivary proteins, especially to basic proline-rich proteins (PRPs). Polymorphic variations in these patterns could form the basis of differences in oral microflora, susceptibility to oral infections and consequent disease.

Bacterial Adhesion↗
PubMed1993

Porphyromonas gingivalis invades oral epithelial cells in vitro.

The aim of the present study was to analyze the adhesive and invasive potential of a number of P. gingivalis strains, in an in vitro system utilizing cultures of human oral epithelial cells (KB cell line, ATCC CCL 17). P. gingivalis strains W50 and FDC 381 (laboratory strains) and OMGS 1738, 1743 and 1439 (clinical isolates) as well as E. coli strain HB 101 (non-adhering, non-invasive control) were used. Adherence was assessed by means of scintillation counting and light microscopy, after incubation of radiolabelled bacteria with epithelial cells. In the invasion assay, monolayers were infected with the P. gingivalis and E. coli strains and further incubated with an antibiotic mixture (metronidazole 0.1 mg/ml and gentamicin 0.5 mg/ml). Invasion was evaluated by (i) assessing presence of bacteria surviving the antibiotic treatment, and (ii) electron microscopy. All P. gingivalis strains adhered to and entered into the oral epithelial cells. After 3 hours of incubation, bacteria were frequently identified intracellularly by means of electron microscopy. The cellular membranes, encapsulating the microorganisms in early stages of the invasive process, appeared later to disintegrate. The presence of coated pits on the epithelial cell surfaces suggested that internalization of P. gingivalis was associated with receptor-mediated endocytosis (RME). Formation of outer membrane vesicles (blebs) by intracellular bacteria indicated that internalized P. gingivalis was able to retain its viability. E. coli strain HB 101 neither adhered to nor invaded epithelial cells.

Bacterial Adhesion↗
PubMed1990

Determination of free progesterone in an ultrafiltrate of saliva collected in situ.

We have investigated the utility of an ultrafiltrate of saliva for measuring progesterone as an indicator of luteal function during the menstrual cycle of women. A filtrate of saliva is collected in the mouth by means of an osmotic pump that accumulates medium containing only molecules less than 12,000 Da. We analyzed the nonextracted ultrafiltrate by a solid-phase immunoassay for progesterone and monitored the mid-luteal surge of lutropin in urine with a liquid-phase radioimmunoassay. Progesterone concentrations in the ultrafiltrate are significantly lower during the follicular phase and increase after the release of lutropin. The concentration of progesterone in the ultrafiltrate correlates closely with total progesterone in matched blood samples (r = 0.84, cycle 1; and r = 0.89, cycle 2). Likewise, we found a good correlation between the results in whole saliva and in the ultrafiltrate (r = 0.95). The described method of obtaining a pre-processed specimen noninvasively simplifies the self-collection of samples by patients (including collection at home); excludes potential interference from microorganisms, desquamated cells, and salivary components; and simplifies the processing of the biological fluid in the laboratory.

Adult↗