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PubMed2003

Oral mucositis and selective elimination of oral flora in head and neck cancer patients receiving radiotherapy: a double-blind randomised clinical trial.

Mucositis is an acute inflammation of the oral mucosa because of radiotherapy and/or chemotherapy. All patients receiving radiotherapy in the head and neck region develop oral mucositis. The aim of this study was to analyse the effects of selective oral flora elimination on radiotherapy-induced oral mucositis, in a double-blind, randomised, placebo-controlled trial. Sixty-five patients with a malignant tumour in the head and neck regions to be treated with primary curative or postoperative radiotherapy participated in this study. The patients received either the active lozenges of 1 g containing polymyxin E 2 mg, tobramycin 1.8 mg and amphotericin B 10 mg (PTA) (33 patients) or the placebo lozenges (32 patients), four times daily during the full course of radiotherapy. Mucositis, changes in the oral flora, quality of feeding and changes of total body weight were assessed. Mucositis score did not differ between the groups during the first 5 weeks of radiotherapy. Nasogastric tube feeding was needed in six patients (19%) of the placebo group and two patients (6%) of the PTA group (P=0.08). Mean weight loss after 5 weeks of radiation was less in the PTA group (1.3 kg) (s.d.: 3.0) than in the placebo group (2.8 kg) (s.d.: 2.9) (P=0.05). Colonisation index of Candida species and Gram-negative bacilli was reduced in the PTA group and not in the placebo group (P<0.05). No effect on other microorganisms was detected. In conclusion, selective oral flora elimination in head and neck irradiation patients does not prevent the development of severe mucositis.

Adult↗
PubMed1992

The predominant microflora of the palatal mucosa in an elderly island population.

The prevalence and microbiology of macrophotographically documented denture stomatitis were studied in denture wearers participating in an interdisciplinary health-monitoring project (Koster Health Project) on the Koster islands, Sweden. Upper dentures were used by 26.6% of the adult population, and 59.2% of the denture wearers had stomatitis. Denture stomatitis type I was identified as sialadenitis. The more severe forms of denture stomatitis (types II and III) demonstrated increased recovery of microorganisms in the palatal mucosa in addition to sialadenitis. Only one proband showed increased growth of fungi. Hemophilus spp. and Bacteroides spp. were the predominating microorganisms in stomatitis types II and III. Shifts in the normal oral flora are suggested to be an important factor for the development of denture stomatitis. It is concluded that bacterial colonization on the palatal mucosa may play an important role in denture stomatitis in this relatively healthy population.

Aged↗
PubMed1992

Evaluation of new anti-infective drugs for the treatment of respiratory tract infections. Infectious Diseases Society of America and the Food and Drug Administration.

These guidelines deal with the evaluation of anti-infective drugs for the treatment of respiratory tract infections. Five clinical entities are described: streptococcal pharyngitis and tonsillitis, otitis media, sinusitis, bronchitis, and pneumonia. A wide variety of microorganisms are potentially pathogenetic in these diseases; these guidelines focus on the bacterial infections. Inclusion of a patient in a trial of a new drug is based on the clinical entity, with the requirement that a reasonable attempt will be made to establish a specific microbial etiology. Microbiologic evaluation of efficacy requires isolation of the pathogen and testing for in vitro susceptibility. Alternatively, surrogate markers may be used to identify the etiologic agent. The efficacy of new drugs is evaluated with reference to anticipated response rates. Establishment of the microbial etiology of respiratory tract infections is hampered by the presence of "normal flora" of the nose, mouth, and pharynx, which may include asymptomatic carriage of potential pathogens. This issue is addressed for each category of infection described. For example, it is suggested that for initial phase 2 trials of acute otitis media and acute sinusitis tympanocentesis or direct sinus puncture be used to collect exudate for culture. Acute exacerbations of chronic bronchitis also present difficulties in the establishment of microbial etiology. These guidelines suggest that clinical trials employ an active control drug but leave open the possibility of a placebo-controlled trial. For pneumonia, the guidelines suggest the identification and enrollment of patients by the clinical type of pneumonia, e.g., atypical pneumonia or acute bacterial pneumonia, rather than by etiologic organism or according to whether it was community or hospital acquired. For each respiratory infection, the clinical response is judged as cure, failure, or indeterminate. Clinical improvement is not acceptable unless quantitative response measures can be applied.

Anti-Bacterial Agents↗
PubMed1984

Permeability of the thermometer sheath when taking oral temperatures.

Oral mercury-in-glass thermometers are contaminated with each use and must be decontaminated prior to reuse. It has been shown that the application of a thermometer sheath prevents contamination of the rectal thermometer. The purpose of the present study is to evaluate sheathed thermometers for contamination after oral use on dentulous patients. One hundred sterile sheathed thermometers were distributed into four groups and subjected to in vitro and in vivo conditions. After clinical use 80% of the sheathed thermometers became contaminated, while not one of those exposed to microorganisms in vitro was contaminated. The cause for contamination was shown to be perforation of the sheath by the dentition. Thus the thermometer sheath is ineffective in preventing contamination of the mercury-in-glass thermometer when used for obtaining oral temperatures from dentulous patients. Sheathed mercury-in-glass thermometers should be decontaminated after each oral use.

Bacteria↗
PubMed1994

An investigation of diterpenes from the leaves of Rabdosia trichocarpa and their antibacterial activity against oral microorganisms.

The ethanolic extract of Rabdosia trichocarpa leaves showed antibacterial activity against cariogenic mutans streptococci and periodontopathic Porphyromonas gingivalis. Chromatographic separation and purification of the extract afforded ten diterpenes, including one novel ent-kauren type compound named trichoranin. Some of these compounds possess potent antibacterial activity against these oral micro-organisms, indicating that these diterpenes may be useful natural substances for the maintenance of oral health.

Anti-Bacterial Agents↗
PubMed2005

Effects of non-surgical mechanical therapy on the subgingival microbiota of Brazilians with untreated chronic periodontitis: 9-month results.

BACKGROUND: Mechanical periodontal therapy is the most common treatment of periodontal infections. It is directed primarily towards removing biofilm and calculus from the root surfaces, leading to ecological changes in the subgingival environment. Thus, the purpose of this study was to evaluate the effects of scaling and root planing (SRP) on the subgingival microbiota of Brazilian subjects with untreated chronic periodontitis over a 9-month period. METHODS: Twenty-five untreated chronic periodontitis patients (mean age 43 +/- 5 years; 20% smokers; 45% males) were selected from a Brazilian population. At baseline, probing depth (PD), clinical attachment level (CAL), visible supragingival biofilm (SB), bleeding on probing (BOP), and suppuration (SUP) were measured at six sites/tooth. Subgingival plaque samples were obtained from 10 sites with the deepest PD (> or =5 mm) of each subject and tested for the presence of 25 oral species by DNA probes and the checkerboard technique. Patients received full mouth SRP and oral hygiene instructions. Clinical and microbiological assessments were repeated at 3, 6, and 9 months after therapy. During this period, all patients received maintenance therapy, including supragingival prophylaxis and reinforcement in home care procedures. The clinical and microbiological parameters examined were computed for each subject and at each visit. Differences over time were sought using the Friedman test. RESULTS: Significant reductions in mean CAL and PD (P <0.01), percent of sites with SB (P <0.01), BOP and SUP (P <0.05) were observed during the course of the study. In general, microbial changes were more pronounced for the mean counts than for the frequency of the microorganisms, particularly at 3 months post-therapy. Significant reductions in prevalence and levels were observed for certain periodontal pathogens including P. gingivalis (P <0.05; P <0.01), T. forsythensis (P <0.01), C. rectus (P <0.01), and A. actinomycetemcomitans (P <0.01; P <0.05). Nevertheless, the frequency of A. actinomycetemcomitans increased to baseline values at 9 months after therapy. Treponema ssp. and Prevotella spp. showed a modest decrease in prevalence, whereas marked reductions in their levels were observed. In contrast, the frequency and counts of the suspected pathogens P. micros and F. nucleatum increased after treatment. Species considered beneficial including Actinomyces spp., some oral streptococci, and V. parvula increased in prevalence, although these two last species tended to return to baseline levels at 9 months. CONCLUSION: In Brazilians with untreated chronic periodontitis, SRP led to clinical improvement associated with a decrease of certain periodontal pathogens, and an increase of beneficial species for up to 9 months after therapy.

Adult↗
PubMed2005

Microbial analysis of the autogenous bone collected by bone filter during oral surgery: a clinical study.

PURPOSE: The purposes of the study presented are to identify the microbial content of the collected bone debris and to determine the antibacterial efficiency of chlorhexidine mouth rinse in reducing the microbial content of the collected bone debris. PATIENTS AND METHODS: Twenty-five patients who had asymptomatic fully impacted mandibular third molars bilaterally underwent surgical removal for prophylactic and orthodontic considerations. Immediately before surgery all patients rinsed with 10 mL of their assigned solution (chlorhexidine or sterile saline) for 2 minutes. Before surgical removal of the teeth, bone debris was collected with a stringent aspiration protocol from the ramus by bone filter. The microbial content of the bone debris was assessed and the bacterial levels between the 2 groups were compared statistically. RESULTS: All samples from both groups (chlorhexidine or sterile saline) yielded viable microorganisms. There was no significant difference between the mean/median colony-forming units (CFU)/g values of both group samples, for aerobes (Streptococcus salivarius) and anaerobes (Bacteroides, Peptococcus, Peptostreptococcus, and Veillonella species). With regard to total microorganisms, the mean CFU/g derived from the chlorhexidine group samples were 1.5 x 10(8) CFU/g per bone sample compared with 1.5 x 10(9) CFU/g for the sterile saline control group (P < .05). CONCLUSION: Although chlorhexidine rinsing immediately before surgery reduced the levels of total microorganisms when compared with stringent aspiration protocol alone, it has not been found effective on aerobic Streptococcus salivarius and, importantly, on anaerobes. The reduced bacterial levels may still carry high infectious risk and may lead to failure in autogenous grafting procedures in oral surgery.

Adolescent↗
PubMed1998

Antibacterial effects of a bioactive glass paste on oral microorganisms.

Bioactive glasses contain oxides of calcium, sodium, phosphorus, and silicon in a proportion that provides the material with surface activity and concomitantly with the property of forming a strong bond with bone. Bioactive glasses have been tested as bone substitutes in different clinical situations. In an aqueous environment, Ca2+, Na+, PO4(3-) , and Si4+ are released from the glass, resulting in a rise in pH and in osmotic pressure in its vicinity. Since these are factors that potentially influence the viability of oral microorganisms at the dentogingival margin, we studied the effects of bioactive glass S53P4 on the oral microorganisms Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Actinomyces naeslundii, Streptococcus mutans, and Streptococcus sanguis. This was done by incubating each microbe in a suspension, in the presence of bioactive glass S53P4 in powder form. A. naeslundii was found to lose its viability within 10 min under the experimental conditions. A. actinomycetemcomitans, P. gingivalis, and S. mutans lost their viability within 60 min. Also for S. sanguis a significant loss of viability was seen within 60 min, but it was the only microbe that had any viable cells left after 60 min. Thus, in aqueous solutions the powdered bioactive glass S53P4 appears to have a broad antimicrobial effect on microorganisms of both supra- and subgingival plaque. Consequently, it could be useful as an ingredient in tooth-care products that may have beneficial effects on oral health both from a cariologic and a periodontal point of view.

Actinomyces↗
PubMed2004

Real-time TaqMan PCR for quantifying oral bacteria during biofilm formation.

A TaqMan PCR was developed for quantifying early colonizer microorganisms in dental biofilms. To design species-specific primers and TaqMan probes, genomic subtractive hybridization was used. This quantitative assay in combination with subtractive hybridization may be of value in the study of microbial ecosystems consisting of related species that are involved in the formation and etiology of biofilms.

Actinomyces↗
PubMed2006

The antimicrobial effect of a triclosan/copolymer dentifrice on oral microorganisms in vivo.

BACKGROUND: The authors compared the in vivo antimicrobial effects on microorganisms from dental plaque, saliva and the tongue in subjects who used a triclosan/copolymer dentifrice and a fluoride dentifrice (control). METHODS: The authors assigned 15 subjects randomly to the control dentifrice or the triclosan/copolymer dentifrice for twice-daily use for one week. They collected samples of plaque, saliva and tongue scrapings six and 12 hours after the final brushing. They analyzed colony-forming units of Veillonella species, Fusobacteria species, total cultivable anaerobes and hydrogen sulfide (H(2)S)-producing bacteria. A one-week washout followed. The authors repeated the protocol with the second dentifrice. RESULTS: The results showed no differences at baseline. Significant reductions (88 to 96 percent) in oral anaerobic bacteria were observed in the triclosan/copolymer group six and 12 hours after brushing compared with the control group (P = .001). Fusobacteria decreased by 77 to 92 percent and Veillonella decreased by 84 to 89 percent six and 12 hours after brushing in the triclosan/copolymer group versus the control group. The triclosan/copolymer group also demonstrated a significant decrease in H(2)S-producing bacteria six and 12 hours after brushing (74 to 85 percent) (P = .001). CONCLUSIONS: Brushing with the triclosan/copolymer dentifrice resulted in significant reductions in microorganisms from the three sites compared with the control dentifrice. CLINICAL IMPLICATIONS: The triclosan/copolymer dentifrice produced sustained effects on oral bacteria for 12 hours.

Adult↗
PubMedDate not supplied

Comparative study of the effects of two bleaching agents on oral microbiota.

This study evaluated the in vivo effects of bleaching agents containing 10% carbamide peroxide (Platinum/Colgate) or 7.5% hydrogen peroxide (Day White 2Z/Discus Dental) on mutans Streptococcus during dental bleaching. The products were applied on 30 volunteers who needed dental bleaching. In each volunteer, one of the two bleaching agents was used on both dental arches one hour a day for three weeks. Analysis of the bacterial counts was made by collecting saliva before (baseline values), during (7 and 21 days) bleaching treatments and 14 days posttreatment. The Friedman non-parametric analysis (alpha=0.05) found no differences in microorganism counts at different times for each group for both agents (p>0.05). The Mann Whitney nonparametric test (alpha=0.05) showed no differences in micro-organism counts for both agents (p>0.05). Different bleaching agents did not change the oral cavity mutans Streptococcus counts.

Adolescent↗
PubMed2005

The microbiological status of patients with periodontitis in southern Estonia after non-surgical periodontal therapy.

Our objective was to investigate the presence of periodontal pathogens in comparison with the total degree of microorganisms after non-surgical periodontal therapy. The study material consisted of microbiological samples from periodontal pockets originating from 140 consecutive patients with chronic generalized severe periodontitis. The subgingival samples from periodontal pockets were obtained by a sterile curette, placed into 2 ml of the VMGA III medium, homogenized and serially diluted in the Brucella broth. 100 microl aliquots from the dilutions were inoculated onto the Brucella and the TSBV agar. The plates were incubated in an anaerobic chamber and under microaerobic conditions. The isolates were identified according to colonial and cellular morphology, the potency disk pattern, and the biochemical profiles. After instrumentation, no periodontal pathogens were isolated in 46 (33%) patients, while 94 patients (67%) were infected with one to five different periodontal pathogens. However, higher degree of the total microflora was positively correlated with number of isolated pathogens, a putative indicator of their presence. Therefore, due to the occurrence of residual microorganisms after non-surgical mechanical treatment, information about the pattern of these pathogens is needed for application of antimicrobial therapy. The level of microbial load in gingival pockets, including both pathogenic and non-pathogenic species, is one of the determinants of presence of residual pathogens after non-surgical periodontal therapy.

Bacteria, Aerobic↗
PubMed2000

Surface properties of lactobacilli isolated from healthy subjects.

OBJECTIVE: Lactobacilli are considered cariogenic micro-organisms. As oral species of lactobacilli have not been thoroughly described, the aim of this work was to isolated and identify these organisms from teeth, tongue, saliva and gum of healthy patients and to describe some of their surface properties. SUBJECTS: Forty-four subjects from Tucumán, Argentina, with D, d and M, m indices equal to 0. MATERIALS AND METHODS: Samples were obtained from different areas of the oral cavity. Microorganisms were cultured in lactobacilli selected media (LBS) and identified morphologically and biochemically. Hydrophobicity was analysed by partition in organic solvents, acidity by affinity with chloroform and basicity with ethyl acetate (MATH method), aggregation and coaggregation in presence of (NH4)2SO4, and haemagglutination with ABO erythrocytes in microplates. RESULTS: Eighty-five lactobacilli were isolated; 29.4% were homofermenter, 44.7% facultative heterofermenter and 25.9% obligate heterofermenter. Predominant species were L. fermentum, L. plantarum, L. salivarius, and L. rhamnosus. Most of the strains showed moderate to high hydrophobicity and demonstrated high acid and basic surface charges with almost 40% showing salt aggregation. Few strains haemagglutinated. CONCLUSIONS: A variety of Lactobacillus species were isolated from healthy mouths, some of whom showed adhesion-related properties such as high hydrophobicity and charged surfaces. Probable mechanisms related to the ecological behaviour of lactobacilli in the oral cavity are discussed.

Acetates↗
PubMed1995

Surveillance of oral cultures for Enterobacteriaceae during bone marrow transplantation.

Bone marrow-transplanted patients can suffer from severe life-threatening infections. Oral bacterial cultures were collected from a group of 40 patients prior to and following bone marrow transplantation every 3 days, following initial preparation and eradication of oral infections. The samples were grown on the Titertek-Enterobac kit specific for Enterobacteriaceae. In 426 oral cultures 30.5% grew gram-negative bacteria, 76.6% of them were Enterobacteriaceae. young male patients had 8.3% positive cultures at the study start, a percentage which constantly increased during later periods. Older patients did not follow the same pattern. Also, the allogeneic transplantation group had a higher percentage of Enterobacteriaceae than the autologous group (49.0 versus 19.5%). In blood cultures 18 out of the 94 positive ones showed the presence of Enterobacteriaceae. The most commonly found microorganisms in oral cultures were Klebsiella oxytoca (23%), Enterobacter cloacae (18%) and Klebsiella pneumoniae (15%). The decrease in the positive oral cultures from 35.0% during the pretransplantation period to 5.4% close to the transplantation, demonstrates that the preparatory protocol used for the prevention of oral infections was highly effective.

Adolescent↗
PubMed1984

Isolation of a Streptococcus mutans strain producing a novel bacteriocin.

A strain of Streptococcus mutans has been isolated that produces a bacteriocin with novel properties. Its antibiotic spectrum includes 123 of 124 strains of S. mutans tested and a variety of other gram-positive microorganisms. Experiments with dialysis membranes indicate that the molecular weight of the bacteriocin is less than 1,000. Mutants of the producer strain were obtained that are deficient in bacteriocin production or produce twofold elevated amounts. The ability of these strains to superinfect or preemptively colonize the oral cavities of rats correlated with the amount of bacteriocin they produced.

Animals↗
PubMedDate not supplied

[Endocytosymbiosis of microorganisms in mammal eukaryotic cells and factors of its regulation].

Morphofunctional equivalents of the process of long-term intracellular prokaryotes--eukaryotes interaction were studied by light and electron microscopy. The mechanisms for adaptation, elaborated in the course of evolution of bacteria-host interaction, were analysed on the ultrastructural level. A concept on the role of hypothalamic nonapeptides, as factors of regulation of intracellular persistence and symbiosis of prokaryotes, is discussed.

Animals↗
PubMed1976

Observations on the feeding mechanism, diet and digestive physiology of Histriobdella homari Van Beneden 1858: an aberrant polychaete symbiotic with North American and European lobsters.

1. The aberrant annelid Histriobdella homari (Polychaeta:Eunicida) lives in the branchial chambers of the marine lobsters Homarus americanus and H. vulgaris where it feeds on the rich microflora of bacteria, blue-green algae and related organisms which grow on the inner surface of the branchial chamber, the setae fringing the edges of the carapace, the gill filaments and, especially, the surfaces and setae of the epipodite plates between the gills. H. homari, therefore, is to be regarded as an epizoic microphagous cleaning symbiote of the lobsters. 2. The alimentary canal consists of mouth, buccal cavity, oesophagus, proventriculus, stomach, intestine and anus. The much-modified proboscis lies ventrally below the oesophagus and proventriculus, with its anterior portions protruding into the rear of the buccal cavity. 3. The proboscis consists of two fixed parallel mandibles, a transverse carrier which slides upon the mandibles and to which is attached, posteriorly, a median flexible dorsal rod and, anteriorly, four pairs of movable articulated maxillae, paired external and internal retractor muscles and various tensor, flexor and extensor muscles. 4. Contraction of the retractor muscles withdraws the carrier and maxillae posteriorly, causing bowing of the dorsal rod which is fixed at its posterior end. Relaxation of the muscles allows the rod to straighten and, thus, causes protraction of the carrier and protraction and lateral expansion of the maxillae. Contraction and relaxation of the relaxation of the retractor muscles are supplemented by appropriate changes in the other muscular components of the proboscis. 5. During feeding the serrated anterior ends of the mandibles are applied to the food, the maxillae are fully expanded and then dawn ventro-posteriorly toward the mid-line by contraction of the retractor muscles in the effective movement of the feeding mechanism. This draws the food organisms across the anterior ends of the mandibles, detaching them from the substratum and allowing their ingestion by ciliary action. The first pair of maxillae are also capable of independent action and can be used while the remainder of the proboscis apparatus is held in the protracted position. 6. Detached microorganisms are entangled in a sticky mucous secretion from the salivary glands; other salivary secretions provide a transport medium for the clumped particles and a third set contain C-esterases which initiate digestion. 7. Ingested food is held briefly in the proventriculus, then passed to the stomach where gland cells secrete A- and C-esterases which continue and extend the digestion initiated by the salivary C-esterases. 8. Some soluble products of gastric digestion are taken up by absorptive cells in the stomach wall and their digestion is completed intracellularly by enzymes which include beta-glucuronidase. Others pass into the intestine for absorption and completion of digestion by cells similar to the gastric absorptive cells but which lack beta-glucuronidase...

Animals↗
PubMed1983

Oral manifestations of tumor and opportunistic infections in the acquired immunodeficiency syndrome (AIDS): findings in 53 homosexual men with Kaposi's sarcoma.

Fifty-three homosexual men with Kaposi's sarcoma (KS) were studied. Twenty-seven had biopsy-proved oral KS, the palate being the most common site. Past or present infections with cytomegalovirus, hepatitis, venereal diseases, and gastrointestinal microorganisms occurred in more than 70%. Oral candidiasis was confirmed in 57%. Heavy marijuana smoking was the most common habit. Transmission of AIDS is thought to be by a viral agent. Precautions involving the use of gloves, eyeglasses, and masks, similar to those recommended for the management of patients with hepatitis B, are urged.

Acquired Immunodeficiency Syndrome↗