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At least 127 records · Page 7Linked to original sources
PubMed1998

Microbiological findings in prepubertal periodontitis. A case report.

Generalized pre-pubertal periodontitis (GPP) is a rare entity that usually affects children with severe systemic diseases. We report the case of a 7-year-old male patient diagnosed with GPP, with no apparent systemic condition, who lost all his primary teeth to periodontal disease. Before extractions, while he was still in mixed dentition the subgingival plaque was collected and analyzed using DNA probes to 40 different microorganisms. Putative periodontopathogens such as Prevotella intermedia, Selenomonas noxia, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans could be identified throughout the mouth. More intriguing was the colonization of the sulcus of some secondary teeth by potentially harmful microorganisms found in pockets of diseased adjacent primary teeth.

Aggregatibacter actinomycetemcomitans↗
PubMed2007

A gene family of putative immune recognition molecules in the hydroid Hydractinia.

Animal taxa display a wide array of immune-type receptors that differ in their specificities, diversity, and mode of evolution. These molecules ensure effective recognition of potential pathogens for subsequent neutralization and clearance. We have characterized a family of putative immune recognition molecules in the colonial hydroid Hydractinia symbiolongicarpus. A complementary DNA fragment with high similarity to the sea urchin L: -rhamnose-binding lectin was isolated and used to screen 9.5 genome equivalents of a H. symbiolongicarpus bacterial artificial chromosome library. One of the resulting 19 positive clones was sequenced and revealed the presence of a 5,111-bp gene organized in 13 exons and 12 introns. The gene was predicted to encode a 726-amino acid secreted modular protein composed of a signal peptide, an anonymous serine-rich domain, eight thrombospondin type 1 repeats, and a L: -rhamnose-binding lectin domain. The molecule was thus termed Rhamnospondin (Rsp). Southern hybridization and sequence analyses indicated the presence of a second Rsp gene. The cDNA from both Rsp genes was sequenced in 18 individuals, revealing high levels of genetic polymorphism. Nucleotide substitutions were distributed throughout the molecule and showed a significantly higher number of synonymous substitutions per synonymous sites than its nonsynonymous counterparts. Whole-mount in situ hybridization and semi-quantitative reverse transcription polymerase chain reaction of microorganism-challenged colonies indicated that Rsp molecules were specifically and constitutively expressed in the hypostome of gastrozooids' mouth. Thus, the combination of (1) comparative analysis on domain composition and function, (2) polymorphism, and (3) expression patterns, suggest that Rsp genes encode a family of putative immune recognition receptors, which may act by binding microorganisms invading the colony through the polyp's mouth.

Amino Acid Sequence↗
PubMed1993

Pigmented Prevotella species in the periodontally healthy oral cavity.

Pigmented Prevotella spp. have been connected with oral infections as well as being part of the healthy gingival flora. The aim of this study was to determine the presence of pigmented Prevotella spp. in saliva and gingival crevice samples from periodontally healthy adults. Twelve Caucasian female subjects (mean age 28 years, range 21-36 years) with no pockets > or = 4 mm, nor bleeding after probing were selected for this study. Paraffin-stimulated saliva was collected first; then, a pooled subgingival bacterial sample was taken with a sterile curette from mesiobuccal surfaces of all first molars. The samples were inoculated on to non-selective and selective media and incubated anaerobically. The most frequent species isolated were Pr. melaninogenica, Pr. intermedia and Pr. loescheü, found in 11, ten and nine subjects, respectively. The mean percentage of the total cultivable anaerobic microflora in salivary/subgingival samples were 14.7/0.6 for Pr. melaninogenica, 3.1/5.3 for Pr. intermedia and 2.6/1.2 for Pr. loescheii. Pr. denticola was found in one saliva sample and Pr. corporis, in two subgingival samples only. The number of different pigmented Prevotella spp. in the same mouth was 2-4 (mean 2.75). In conclusion, Pr. melaninogenica, Pr. intermedia and Pr. loescheii seem to be common microorganisms in the periodontally healthy oral cavity.

Adult↗
PubMed1984

Contamination of dental unit cooling water with oral microorganisms and its prevention.

Each time the handpiece turbine is stopped while the bur is still in the patient's mouth, almost 1 ml of microbe-laden oral fluids may be aspirated into the average dental unit water line by the retraction valve present in the dental unit. This fluid may contain an average in excess of 54,000 microorganisms per milliliter, including both facultative and obligate anaerobic bacteria of medium to high virulence. Other infectious agents including hepatitis, herpes, influenza, and other upper respiratory viruses may also be present. This germ-laden water may then be sprayed into the mouth of the next patient, possibly initiating an oral or upper respiratory tract infection. Sterilizing the handpiece between appointments, although of great significance in the prevention of disease transmission, will not totally eliminate the problem discussed here as almost 95% of the oral fluid aspirated into the dental unit went past the handpiece and into the handpiece cooling water line. Complete elimination of the retraction valve in the unit is the most effective means of solving this problem, but, with present dental unit designs, this may result in water dripping onto the patient. A viable alternative is the installation of a check valve (anti-retraction valve) downstream from the retraction valve. Installation of a check valve resulted in an almost 4,000-fold decrease in this contamination. The attachment of a check valve will have no effect on normal less virulent bacteria already present in tap water. These bacteria colonize the water lines of the dental unit and are then continually shed into the water in numbers often as high as 1,000,000 CFU/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2002

Influence of a single gamma-irradiation on rat microflora.

Changes in leukocyte counts and in the gut microflora of laboratory rats irradiated with single whole-body dose of gamma rays (5.0 Gy) were determined. The number of leukocytes was lower especially 1 and 2 weeks after irradiation. A significant decrease in lymphocytes was observed 1 week and in monocytes 1 and 2 weeks after irradiation. In parallel with these changes, an increase in common microflora was observed; some microorganisms, which normally are not present in duodenum, liver and mouth cavity, were detected in these organs.

Animals↗
PubMed2001

The use of chemotherapeutic agents in localized periodontal pockets.

Gingival diseases are the most widely dispersed diseases in the United States. In some patients, periodontal disease appears in a generalized form, but more often it appears in localized areas. Furthermore, after treatment with scaling and root planing in generalized cases, the disease is often reduced to a few local areas in the patient's mouth. Because periodontitis is a bacterial infection with known pathogenic microorganisms, the local delivery of antimicrobial agents has been considered to be a possible solution for treating and controlling localized forms of periodontal disease. Three local chemotherapeutic agents are reviewed in this paper: tetracycline fiber, doxycycline gel, and chlorhexidine chip. With the advancement of local drug delivery systems, restorative dentists, periodontists, and their patients have new alternatives for the treatment of periodontal disease. Local chemotherapeutic agents offer an additional mode of therapy and should be used on a case-by-case basis, not necessarily as an initial treatment.

Anti-Bacterial Agents↗
PubMedDate not supplied

Local chemotherapeutics as an adjunct to scaling and root planing.

Gingival diseases are the most widely held diseases in America. In some patients, periodontal disease appears in a generalized form, but more often it appears in localized areas. Furthermore, after treatment with scaling and root planing (SRP) in generalized cases, the disease is often reduced to a few local areas in the patient's mouth. Since periodontitis is a bacterial infection with known pathogenic microorganisms, the local delivery of antimicrobials has been considered to be a possible solution for treating and controlling localized forms of periodontal disease. Three current local chemotherapeutic agents are reviewed in this paper: doxycycline gel, chlorhexidine chip and minocycline microspheres. With the advancement of local drug delivery systems, clinicians and their patients have new alternatives for treatment of periodontal disease.

Chlorhexidine↗
PubMed1993

Microbial carriage, sepsis, infection and acute GVHD in the first 25 BMT at the Royal Liverpool Children's Hospital.

The first 25 BMTs at the Royal Liverpool Children's Hospital (Alder Hey) were performed between April 1987 and July 1991. The aim of this report is to evaluate selective decontamination of the digestive tract (SDD) during the first post-BMT month in this series of 14 allografts and 11 autografts. SDD is a method used to abolish carriage of potentially pathogenic microorganisms including yeasts, Staphylococcus aureus and Gram-negative bacilli (GNB). Chlorhexidine mouth wash was used to decontaminate the oropharynx, and neomycin, colistin (polymyxin E) and nystatin (NEOCON) were given to eradicate gut carriage. Oropharyngeal decontamination was successful in 48% of patients, gut carriage was abolished in 60%, and eradication of the carrier state at both sites was achieved in 33%. A septic response was seen in 76% of children and 36% developed septicaemia (indigenous Gram-positive cocci only). A low carriage index for the target microorganisms during the study manoeuvre of SDD was associated with negative blood cultures (p < 0.01). Acute GVHD occurred in 28% of allografts, but was seen in none of the successfully decontaminated children (p < 0.05). It is concluded that septicaemia from yeasts and GNB, but not the septic response, were successfully prevented by SDD.

Adolescent↗
PubMed1977

Oral infection in immunosuppressed renal transplant patients.

The most common cause of death in patients taking immunosuppressive (IS) drugs is infection. Many of the microorganisms which infect these IS patients may be found in the mouth, but the mouth has not been investigated as a potential source of lethal infection. In view of this, we studied twenty-seven IS patients taking Imuran and prednisone for 6 to 61 weeks and eighteen normal controls. The patients were followed monthly, and the incidence of oral and systemic complications was recorded. There were no deaths due to infection during the 10-month study period. Oral infection occurred as frequently as pneumonia or urinary tract infection. Systemic factors which were related to the development of dental infection were lymphocyte count and length of time on immunosuppressive drug therapy.

Adult↗
PubMed1991

Processes for water reclamation.

Water treatments fall into two broad classes; those that remove or destroy specific classes of pollutants, i.e. color, metal ions, hardness, sediment, bacteria, etc., and those that remove water from nearly all of the pollutants. The first class includes sedimentation, biological treatment by microbes, chemical precipitation, adsorption on active carbon or ion exchange resins, and disinfection. The second class includes distillation, freezing and reverse osmosis (RO). The first class are the least expensive in terms of energy and have a long history of successful use on a large scale to reclaim water containing sewage. Most of the second group are energy intensive and have been used primarily on a moderate scale. All processes, except disinfection, leave a residual sludge or brine that contains a substantial quantity of water. Many of the problems of treating waste water for reuse on Earth stem from the fact that waste water carries pathogenic organisms from one location to another and may spread disease over long distances. In a closed group, such as in a Space Station, there are so many other routes for transfer of microorganisms, i.e. in the air, on surfaces, by hand-to-mouth, that undue emphasis on disinfection of water is inappropriate. Successful examples of water reuse on Earth are reviewed in terms of their possible application in space.

Carbon↗
PubMed1982

The effect of short-term administration of minocycline HCl on gingival inflammation and subgingival microflora.

The purpose of this investigation was to determine the efficacy of minocycline hydrochloride in the management of subgingival microorganisms and periodontal disease. In a double-blind, split-mouth study, minocycline or placebo was administered systemically for 7 days to 26 adults with moderate-to-serve periodontitis. Four study groups were examined: (i) minocycline-scaled, (ii) minocycline-unscaled, (iii) placebo-scaled, and (iv) placebo-unscaled. The minocycline-scaled group responded most favorably, with improved gingival health for at least 49 days and with marked reductions in total bacterial counts and proportions of spirochetes for at least 70 days (termination of the study). Minocycline administration with no periodontal scaling and root planing also resulted major, long-lasting shifts in the subgingival microflora. Scaling alone was least effective in changing the microflora. The data indicated that minocycline may be a useful adjunct in the treatment of periodontal disease. Further studies are needed, however, to determine the long-term effect of minocycline therapy on the periodontal attachment level.

Adult↗
PubMed1990

[Plaque accumulation on various veneering resins--a clinical study].

Initial plaque accumulation on five veneering resins was investigated to determine differences in vitality and adhesion of microorganisms. After 24 hours of exposure of the specimens in the mouth, the vitality of the bacteria was reduced. The vitality and the adhesion increased only a little until the fourth day. The high plaque accumulation observed in vivo on resin veneers seems to depend primarily on the degeneration and mechanical lesions of the surface after a certain time in mouth.

Bacterial Adhesion↗
PubMedDate not supplied

[The classification and the monitoring of the state of mouth riverine and lacustrine ecosystems in lake Baikal based on the composition of local microbiocenoses and their activity].

The paper presents the results of the long-term investigation of microbial communities in the technogenically vulnerable mouth riverine and lacustrine ecosystems of Lake Baikal. The structural and functional parameters of the microbial communities were analyzed from the standpoint of developing destructive processes. The analysis showed that the total number of microorganisms (TNM), the number of saprophytic bacteria (NSB), and bacterial production (BP) were greater in the river-mouth water than in the near-mouth lake water. In the offshore direction, TNM and NSB decreased by a factor of 1.5 to 2, and BP decreased by a factor of 4 to 7. Based on TNM, NSB, and BP data, we classified the Lake Baikal rivers with respect to the degree of the impact of human activities on them. The degrading capability of the riverine microbial communities was found to be such that they degrade daily from tenths of a percent to 3.5% of the total amount of organic compounds polluted the river waters.

Bacteria↗
PubMed2005

[Microbiological investigations and studies of phagocytic activities of peripheral neutrophils during the treatment of parodontitis by Unimag].

During the treatment by Unimag (UN), quantity of microbes in the mouth cavity of patients with periodontitis (PD), significantly decreases in comparison with the patients treated by traditional scheme. That is due to direct and indirect influence of UN on the pathogenic microorganisms. During the treatment of patients with PD by UN, quantity of Gram-negative microbes gradually decreases and their substitution by Gram-positive microbes, typical for mouth cavity, takes place. On the background of the treatment by UN, phagocytic activity (PA) of polynuclear cells (PC) increases. In comparison with the patients treated by traditional scheme, increases both phagocytic number and number of active neutrophils. On 14-15 days after beginning of treatment of patients with PD by traditional scheme, PA of PC does not change significantly. Reduction of the microbial number in the mouth cavity and the active substitution of Gram-negative microbes by Gram-positive microorganisms during the treatment of patients with PD by UN, have prognostic importance and together with the reinforcement of PA of PC indicate to the improvement of the therapeutic effect and shortening of the duration of the treatment.

Adult↗
PubMedDate not supplied

Study on the occurrence of microorganisms on the post-surgical maxillary prostheses with obturators and in the post-surgical cavities of maxilla.

The bacterial environment of the mouth cavity may be subjected to change under influence of various factors, such as surgical removal of neoplasm tumors and in consequence the wearing of post-surgical prostheses with obturators. The purpose of the paper was to study the conceivable differences in occurrence of particular types of microorganisms found on the margin of post-surgical cavities and on the prosthetic obturators. The performed microbiologic examinations revealed that more pathologic bacterial flora was found on the obturators than in the post-surgical cavities. The authors conclude that the post-surgical patients should pay more attention to the very accurate hygiene of their prostheses and the mouth cavity as well.

Adult↗
PubMed2006

Psychological determinants of reactions to food risk messages.

In recent years, European countries have witnessed a number of food crises such as dioxin-contaminated chicken, foot-and-mouth disease, and BSE. In such cases, food might be contaminated by microorganisms or chemicals that could pose a risk to the consumer. These cases attract media attention and might instigate the consumer to reduce the consumption of the allegedly contaminated products. Although a decline in consumption of (potentially) contaminated products has been observed, it is not yet clear what determines the individual's reaction to food risk messages. To study the psychological determinants of the reaction to food risk messages, a survey was conducted in the Netherlands (n= 280). Subjects had to imagine two situations involving chicken contamination and report how they would react behaviorally if this situation occurred. Risk perception, affective response, perceived susceptibility to foodborne disease, self-efficacy, outcome expectation, trust, experience with foodborne disease, and need for information were also assessed. It was found that 60% of the subjects would allegedly avoid the risks by not consuming chicken for a while and approximately 60% would seek additional information. Risk avoidance was significantly related to information seeking and the psychological determinants, especially risk perception, affective response, need for information, perceived susceptibility to foodborne disease, and trust. Seeking information was also significantly related to risk perception, affective response, need for information, susceptibility to foodborne disease, and trust, but to a lesser degree. A model describing the relationships between the variables was tested using AMOS. Results are presented and implications are discussed.

Adult↗