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At least 649 records · Page 36Linked to original sources
PubMed1998

Adherence of Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans to human buccal epithelial cells, from healthy persons and HIV carriers, under the influence of Broncho Vaxom in vitro and ascorbic acid in vivo.

We examined the in vitro effect of Broncho Vaxom (BV) (an immunobiotherapeutic preparation containing a lysate made from bacteria often involved in respiratory tract infections) on adherence of Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans to human buccal epithelial cells (BEC) of healthy volunteers and HIV carriers. We also examined the ex vivo effect of ascorbic acid on the adherence of the same microorganisms to BEC of HIV carriers. The study reached the following conclusions: The presence of BV in vitro significantly reduces the adherence of the tested strains to BEC from healthy persons and HIV carriers. No significant difference was observed between healthy persons and HIV carriers regarding the adherence of the tested strains to BEC. Significant difference in the adherence of the tested strains to BEC was observed between HIV carriers who had been taking ascorbic acid over a 3-month period and those who had not. There was no further reduction in the adherence of the tested strains to BEC from HIV carriers who had been taking ascorbic acid in the presence of BV in vitro.

Adjuvants, Immunologic↗
PubMed1996

Antimicrobial treatment of periodontal diseases disturbs the human ecology: a review.

Periodontal diseases are associated with specific pathogenic microorganisms and therefore antimicrobial agents are often used in the treatment of patients with periodontitis refractory to conventional mechanical therapy. Perorally administered antimicrobial agents often lead to ecological disturbances in the normal oral and intestinal microflora with overgrowth of potentially pathogenic microorganisms, which may spread within the host or from patient to patient, causing infections. The use of antimicrobial agents also promotes the emergence of bacterial drug resistance, both in the periodontal pocket and in the normal oral and intestinal microflora. Topical administration of antimicrobial agents in the periodontal pockets causes restricted disturbances in the intestinal microflora, although there is a substantial risk of development of resistance at the site of application. A number of clinical studies imply that correct use of antimicrobial agents might be beneficial for a subset of patients with adult or juvenile periodontitis. The choice of antimicrobial agent should always be based on accurate microbial analyses of the subgingival microflora and in vitro antimicrobial susceptibility tests of the most important periodontal pathogens. Preferably, agents with low potential of causing ecological disturbances should be used.

Anti-Bacterial Agents↗
PubMed1998

Helicobacter pylori: the mouth, stomach, and gut axis.

The aim of this study was to identify the natural reservoir and route of transmission of Helicobacter pylori infection. Two hundred eight (208) dyspeptic patients (114 males, 94 females; peak age of cohort, 50-59.9) were recruited. Specimens were collected from saliva, supra- and subgingival dental plaque, tongue scrapings, and oropharyngeal swabs. At subsequent endoscopy, gastric antral biopsy was performed for the rapid urease test (RUT), microbiological culture, and, in some patients, histology. Gastric juice samples were aspirated, and in 50 patients duodenal aspirate was collected. Polymerase chain reaction (PCR) with primers targeted to the 16S rRNA sequence of H. pylori was also employed for each of the specimens. In those patients where H. pylori was detected from multiple sites (dental plaque, gastric juice, gastric biopsy, and duodenal aspirate), restriction endonuclease digestion with Hae III was performed to determine if they were epidemiologically linked. The results indicated that 15/208 patients (7%) tested positively for H. pylori by PCR in dental plaque; only 2 samples were positive by culture. In none of the other oral sites sampled was H. pylori detected by any test used in the study. Gastric juice and gastric biopsy specimens from 36/ 208 patients (17%) and 114/208 patients (55%), respectively, were positive by PCR. Duodenal aspirate from 6/50 patients (12%) also tested positively by PCR. All specimens tested by restriction endonuclease digestion with Hae III (15/15 patients) were positive in both antral biopsy and gastric juice specimens, as well as 5 specimens from the duodenal aspirate. Four of the dental plaque strains had restriction patterns similar to those of the stomach and duodenal sites, providing evidence that these sites were infected with the same strain of H. pylori. In conclusion, the results suggest that H. pylori selects the gastric mucosa as its preferred site. The detection in dental plaque could indicate that the oral cavity may act as a reservoir or sanctuary for the organism. Whether H. pylori is a resident or transient oral microorganism is still unclear, although it is more likely to be transient in nature.

Bacterial Typing Techniques↗
PubMed1989

A comparison of fibronectinolytic activities from several oral bacteria.

Fibronectinolytic activity from two Gram-positive microorganisms (Streptococcus mutans and Bacterionema matruchotii), and from three Gram-negative oral bacteria (Bacteroides intermedius, Bacteroides gingivalis and Haemophilus actinomycetemcomitans) were compared. 125I-labelled human plasma fibronectin (FN) was incubated either either with bacterial extracts or with concentrated culture medium samples and the patterns of FN-degradation products were determined by SDS-PAGE. Results to date have shown that Streptococcus mutans, Bacterionema matruchotii and Haemophilus actinomycetemcomitans were unable to degrade FN. On the other hand the Gram-negative Bacteroides intermedius and Bacteroides gingivalis were shown to contain Fn-degrading activity. The highest activity was found in the bacterial extracts of Bacteroides gingivalis. Inhibition assays demonstrated that fibronectinolytic activity of Bacteroides gingivalis occurred predominantly by cysteine proteinase(s) while that of Bacteroides intermedius by a common action of serine and cysteine proteinases.

Actinomycetaceae↗
PubMed2000

In vitro antimicrobial activity of propolis and Arnica montana against oral pathogens.

Arnica and propolis have been used for thousands of years in folk medicine for several purposes. They possess several biological activities such as anti-inflammatory, antifungal, antiviral and tissue regenerative, among others. Although the antibacterial activity of propolis has already been demonstrated, very few studies have been done on bacteria of clinical relevance in dentistry. Also, the antimicrobial activity of Arnica has not been extensively investigated. Therefore the aim here was to evaluate in vitro the antimicrobial activity, inhibition of adherence of mutans streptococci and inhibition of formation of water-insoluble glucan by Arnica and propolis extracts. Arnica montana (10%, w/v) and propolis (10%, w/v) extracts from Minas Gerais State were compared with controls. Fifteen microorganisms were used as follows: Candida albicans--NTCC 3736, F72; Staphylococcus aureus--ATCC 25923; Enterococcus faecalis--ATCC 29212; Streptococcus sobrinus 6715; Strep. sanguis--ATCC 10556; Strep. cricetus--HS-6; Strep. mutans--Ingbritt 1600; Strep. mutans--OMZ 175; Actinomyces naeslundii--ATCC 12104, W 1053; Act. viscosus OMZ 105; Porphyromonas gingivalis; Porph. endodontalis and Prevotella denticola (the last three were clinical isolates). Antimicrobial activity was determined by the agar diffusion method and the zones of growth inhibition were measured. To assess cell adherence to a glass surface, the organisms were grown for 18 h at 37 degrees C in test-tubes at a 30 degree angle. To assay water-insoluble glucan formation, a mixture of crude glucosyltransferase and 0.125 M sucrose was incubated for 18 h at 37 degrees C in test-tubes at a 30 degree angle. Arnica and propolis extracts (20 microl) were added to these tubes to evaluate the % of inhibition of cell adherence and water-insoluble glucan formation. The propolis extract significantly inhibited all the microorganisms tested (p < 0.05), showing the largest inhibitory zone for Actinomyces spp. The Arnica extract did not demonstrate significant antimicrobial activity. Cell adherence and water-insoluble glucan formation were almost completely inhibited by the propolis extract at a final concentration of 400 microg/ml and 500 microg/ml, respectively. The Arnica extract showed slight inhibition of the adherence of the growing cells (19% for Strep. mutans and 15% for Strep. sobrinus) and of water-insoluble glucan formation (29%) at these same concentrations. Thus, the propolis extract showed in vitro antibacterial activity, inhibition of cell adherence and inhibition of water-insoluble glucan formation, while the Arnica extract was only slightly active in those three conditions.

Actinomyces↗
PubMed2005

[Bactericidal effects of human oral and urinary system epithelial cells against different Escherichia coli strains].

The functions of epithelial cells are more than a physical selective barrier for protection from mucosal pathogens. The epithelial response regulated by host-microorganism interaction may change due to histological and physiological differences between sterile and nonsterile sites. In this study we examined the presence of a difference between bactericidal capacities of urinary and oral epithelial cells against different strains of Escherichia coli. Oral epithelial cells were collected from unstimulated saliva and uroepithelial cells were collected from urine of eight healthy volunteers. E. coli K12 and O75 strains and epithelial cells were prepared for the experiment, added to microplates and incubated for one hour. The growth of bacteria was detected by the quantitative colony counting method. Antibacterial effects of the oral and urinary epithelial cells against E. coli K12 and O75 strains were 49.8%, 34.7%, 45.7% and 29.2%, respectively. As a result, it was detected that the antibacterial activity of oral epithelial cells to E. coli K12 and O75 were higher than urinary epithelial cells.

Cells, Cultured↗
PubMed1995

The prevalence of Staphylococcus aureus, Enterobacteriaceae species, and Candida species and their relation to oral mucosal lesions in a group of 79-year-olds in Göteborg.

A subject sample comprising 100 persons (47 men and 53 women) 79 years of age and selected on a statistical basis (representing all persons of that age living in Göteborg) was the object of a general medical, clinical, and microbiologic study of the prevalence of microorganisms in the oral cavity known to cause opportunistic infections. A high prevalence of diseases and frequent medications were recorded among the participants. Staphylococcus aureus was present in five patients and Enterobacteriaceae species in only one individual. Candida albicans was not found in any samples from the palatal mucosa of the 25 individuals without dentures. Of 36 healthy denture wearers C. albicans was found in 9 (25%). In 39 persons with denture stomatitis C. albicans was obtained in 11 (28%) of the samples from the mucosa, 29 (74%) from the dentures, and 10 (26%) from the angulus oris. The prevalence of S. aureus, enteric rods, and C. albicans was low in the elderly population and, when present, correlated with the presence of dentures. No association with the patients' general health or drug use was obtained.

Aged↗
PubMed1998

[Peculiarities of cosmonauts fauces flora].

In the course of the work done the specific and quantitative composition of the streptococcal autoflora of the fauces of the cosmonauts and the members of backup drew was investigated. In populations of isolated microorganisms the non-pathogenic streptococci have dominated among which S. salivarius prevailed. The same species has constantly been isolated in all the cosmonauts, pre- and postflight. Observation of the microflora state of the fauces at different stages of their professional activity made it possible to reveal the peculiarities of an individual dynamics in the number of nonpathogenic streptococci isolated from tampon depending on the participation of the test-subjects in the previous space missions. This is evidently a reflection of the effect of psychoemotional tension on the state of colonization resistance (CR) of the fauces mucosa and, as result of this, on its microflora. In turn, the occurrence of the individual species of conditionally-pathogenic streptococci after the mission points to a decrease in the CR under effect of unfavourable factors of space mission.

Astronauts↗
PubMed1990

Evaluation of the activity of four antimicrobial agents using an in vitro rapid micromethod against oral streptococci and various bacterial strains implicated in periodontitis.

The activity of various antibacterial agents (amoxicillin, josamycin, doxycycline and metronidazole) was established in vitro using a rapid micromethod. The activity of these agents, which are widely used in oral medicine, was evaluated against microorganisms responsible for periodontitis and bucco-dental infections. Their action against alpha-hemolytic streptococci (including pneumococci) which make up the majority of the indigenous oral flora was also tested. Amoxicillin was found to be effective against all the strains tested. Doxycycline was active against periodontal bacteria, but not against 50% of the streptococcal flora. Josamycin was found to be effective against streptococci, but appeared without effect on Eikenella corrodens and Actinobacillus actinomycetemcomitans. Metronidazole, inactive against streptococci, displayed greater activity towards the strict anaerobes. The use of these antibiotics for the treatment of bucco-dental infections, especially periodontitis, is discussed. For periodontitis and periodontal suppurations, antimicrobial agents present a valuable adjunct to local treatments such as scaling or rootplaning. This may prevent more serious infections such as endocarditis that can develop after tooth extraction.

Actinobacillus↗
PubMed2002

Oro-dental bacteria in various atherosclerotic arteries.

Chlamydia pneumoniae DNA has been detected in at least 40% of all major arteries affected by atherosclerosis, but several other microorganisms have also been detected. In this study, diseased vessels were evaluated for the presence of the DNA of seven oro-dental bacteria and two nonoral bacteria. A polymerase chain reaction technique was employed using primer pairs based on 16S rRNA genes. Of 32 specimens tested, 10 (31.2%) were DNA positive: seven for Actinobacillus actinomycetemcomitans and three for Prevotella intermedia. The DNA was found in specimens from the aorta and the iliac, internal mammary and coronary arteries. Eleven (35.4%) of 31 specimens had been shown previously to be positive for Chlamydia pneumoniae DNA. A mixture of chlamydiae and oro-dental bacteria was found in three cases. These findings may have implications for antibiotic prophylaxis of coronary heart disease if directed solely at Chlamydia pneumoniae.

Aorta↗
PubMed2003

[Identification of chlamydia and (or) chlamydia-like microorganisms by light microscopy confirmed by electron microscopy and fluorescent in situ hybridization].

Using light microscopy, we have shown that chlamydia and/or chlamydia-like microorganisms are registered in 20-25% of the healthy part of human population, whereas in patients of the same age with gynecological problems these were found in 40-50%. Commonly, the infection was slightly manifested (less than 5% of cells are infected). These results were confirmed in four months but only in heavily infected patients. The light microscope data are confirmed by observations with electron microscopy, and by FISH hybridization of the total chlamydial DNA on cytological preparations with chlamydial inclusions. In some cases, microcolonies revealed by FISH hybridization occupied the majority of the cytoplasm volume. Occasionally, the DNA material was found on the nuclear surface. It seems likely that in heavily infected cells chlamydia are able to penetrate into the perinucular space.

Chlamydia↗
PubMedDate not supplied

Quantitative and functional neutrophil deficiencies.

Neutrophil is a cell involved in the maintenance of homeostasis of the organism. It plays an important role in the elimination and control of certain pathogenic microorganisms. Deficiency in function and quantity of neutrophils, either due to congenital or secondary etiological extrinsic factors, lead to recurrent infectious processes of variable severity. The most frequent oral complications in these patients are ulcers, periodontal disease and candidiasis. Due to their high susceptibility to infections and the risk implied in undergoing surgical procedures, actions leading to a higher degree of prophylaxis must be carried out on these patients (oral hygiene habits, fluoridation, dietary advise, etc.). The use of granulocyte colony-stimulating factors (G-CSF) allows, in some cases, the fullfillment of some, until recently considered controversial dental procedures. Its administration demands an adequate selection of patients and a close collaboration between physician and dental practitioner. Despite G-CSF effectiveness, dental treatment in severe neutropenic patients must be carried out in a hospital and, in some cases, regardless of adequate care, the progress of periodontal disease cannot be avoided.

Humans↗
PubMed2000

Influence of antimicrobial subinhibitory concentrations on hemolytic activity and bacteriocin-like substances in oral Fusobacterium nucleatum.

Fusobacterium nucleatum is considered for its role in colonization of initial and late microorganisms in dental plaque and for its coaggregation with other bacterial species. It is known that action of different antimicrobial substances may interfere with either virulence factors or with host-bacteria interaction. The goal of this study was to examine the influence of subinhibitory concentrations of chlorhexidine, triclosan, penicillin G and metronidazole on hemolytic activity and bacteriocin-like substance production of oral F. nucleatum. A high resistance to penicillin G was observed and 63% of the isolates were beta-lactamase positive. All the tested isolates were susceptible to metronidazole. F. nucleatum isolates grown with or without antimicrobials were alpha-hemolytics. Bacteriocin-like substance production was increased in isolates grown with penicillin G. Impaired production of hemolytic or antagonic substances can suggest a role in the regulation of oral microbiota.

Adult↗
PubMed1988

Efficacy of oral sucralfate suspension in prevention and treatment of chemotherapy-induced mucositis.

The efficacy of orally administered sucralfate suspension in preventing and treating chemotherapy-induced mucositis was evaluated in a double-blind trial. Forty-eight children and adolescents with newly diagnosed acute nonlymphocytic leukemia were randomized to receive suspensions of either sucralfate or placebo orally every 6 hours during the first 10 weeks of intensive remission-induction chemotherapy. Patients given sucralfate suspension were less likely than subjects receiving placebo to acquire colonization with potentially pathogenic microorganisms: 14 (58%) of 24 versus 22 (92%) of 24, respectively (p = 0.008). However, no effect on preexisting colonization was noted. Subjective reporting of discomfort, objective scoring of the severity of mucositis, and the maximal percent of body weight lost during therapy were similar; 58% of patients receiving sucralfate reported no oral pain compared with 25% receiving placebo (p = 0.06). Ten episodes of gastrointestinal bleeding, 25 documented infections, and 886 days with fever were also equally distributed between sucralfate and placebo groups. We conclude that sucralfate suspension is of limited, if any efficacy, in the prevention and treatment of chemotherapy-induced mucositis. Sucralfate administration can, however, reduce acquisition of alimentary colonization with potential pathogens, perhaps by interfering with adherence to mucosal membranes.

Administration, Oral↗
PubMed1990

The incidence of periodontopathic microorganisms in young children.

Thirty-six children in 4 cohorts of 0-1 week, 1-6 months, 1-2 years and 2-2 1/2 years of age were examined for the presence of black-pigmented Bacteroides species and some other bacteria suspected of being involved in the subsequent development of periodontal destruction. None of the sought-after bacteria were detected in the first week of life. Bacteroides intermedius and Bacteroides melaninogenicus were detected as early as 1 month after birth. Both of these bacteria were detected in 16-37% of children in the different cohorts. Bacteroides denticola was detected in one child. Other black-pigmented species including Bacteroides gingivalis and Bacteroides loescheii were not detected. Eikenella corrodens was detected in 62% of children under 6 months. Capnocytophaga spp. were detected in 12% and Fusobacterium nucleatum in 25% of children in this age group. With increasing age there was a trend towards an increase in the number of children with F. nucleatum but other bacteria were detected in similar numbers of children throughout the 3 older cohorts. Actinobacillus actinomycetemcomitans was not detected at any age.

Age Factors↗
PubMedDate not supplied

Prevention of bacterial leakage into and from prefabricated screw-retained crowns on implants in vitro.

Previous in vitro studies have shown that a mean gap of less than 4 microns between prefabricated crowns and implants of the Ha-Ti implant system is not a barrier to infiltration by Staphylococcus aureus. These studies confirmed earlier in vivo work showing that a multitude of oral microorganisms could colonize and infiltrate these gaps. In the present investigation, 30 Ha-Ti implant-crown assemblies were tested for bacterial leakage after the gaps were sealed with the chlorhexidine-containing varnish Cervitec. S. aureus leakage into the totally submerged test specimens was detected in 1 of 5 samples incubated for 4 weeks, while no leakage was detected in specimens incubated for 3, 5, 6, 7, and 8 weeks. When the sealed test specimens were partially submerged (that is, excluding the screw hole of the crown) and incubated for 3 to 11 weeks, none of the internal surfaces of the 30 test specimens manifested contamination. The clinical relevance of gap sealing in maintaining inflammation-free marginal mucosa and in achieving clinically successful treatment of peri-implantitis has yet to be determined.

Anti-Infective Agents, Local↗
PubMed1989

New trends in antibiotic prophylaxis of infective endocarditis in patients undergoing surgery in the oral cavity.

Viridans-streptococci, which normally reside in the oral cavity, are still the most common pathogens in infective endocarditis. During surgical procedures in the oral cavity, pharynx and respiratory tract, microorganisms may disseminate into the blood and cause infective endocarditis in predisposed patients. It is, therefore generally considered that these patients should be protected during surgery by an effective and simple antibiotic regimen. During recent years new recommendations for prevention of endocarditis have been presented in several countries. Single high dose amoxycillin or 2-dose phenoxymethylpenicillin are used in normal risk patients while 2-dose erythromycin or single high dose clindamycin may be used in patients allergic to penicillins. Parental agents are usually recommended in high risk patients with prosthetic heart valves, however, some countries prefer to administer peroral prophylaxis. Topical prophylaxis in the oral cavity is not included in any national recommendation, but may decrease the magnitude, as well as the frequency, of postsurgical bacteremia. Commonly used antiseptics such as chlorhexidine are not selective enough and causes overgrowth of some viridans-streptococci. More selectively acting agents, such as topical vancomycin, appear to be more suitable.

Anti-Bacterial Agents↗
PubMed1981

Risk factors for infections of the oropharynx and the respiratory tract in patients with acute leukemia.

The pathogenicity of microorganisms isolated by surveillance cultures, the neutrophil count in the peripheral blood, and the interaction of the two factors were analyzed as risk factors for infections of the oropharynx and the respiratory tract in patients with acute leukemia being treated in strict reverse isolation under antimicrobial modulation. A statistical method was developed for the identification of bacteria, the presence of which was correlated with an increased risk of infection. A significantly increased risk was found mainly for species of Klebsiella, Enterobacter, Proteus, and Pseudomonas. The degree of neutropenia was significantly correlated with the risk of infection, which was influenced by the microbiologic state of the oropharynx. Thus, patients with gram negative bacilli had significantly more days with infection at all levels of neutropenia than patients without gram-negative bacilli. These two risks factors were additive but did not potentiate each other.

Acute Disease↗