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At least 397 records · Page 22Linked to original sources
PubMed1998

Retention of oral microorganisms on cobalt-chromium alloy and dental acrylic resin with different surface finishes.

STATEMENT OF PROBLEM: The effect of surface finish of dental materials on the subsequent contamination by microorganisms. PURPOSE: This study compared the retention of Streptococcus oralis, Actinomyces viscosus, and Candida albicans on polished, sandblasted (fine and coarse) and electrobrightened cobalt-chromium alloy and dental acrylic resin to assess in vitro the effect of such techniques on prosthesis contamination. MATERIAL AND METHODS: Standardized cell suspensions were incubated with test materials for 1 hour at 37 degrees C, after which retained cells were counted by using image analysis (percentage area of a microscopic field covered by cells). RESULTS: Retention of bacterial cells was substantial (S oralis 12% to 20% and A viscosus 9% to 16%) irrespective of surface finish. Maximal retention was observed on cobalt-chromium alloy that had undergone fine sandblasting and electrobrightening (P < .01). For C albicans, an increase in surface roughness (0.15 to 3.53 microns) resulted in an increase in retention (3% to 9%). CONCLUSION: Cell size and the type of roughening significantly affected the retention of microorganisms on surfaces. Electrobrightening of cobalt-chromium alloy did not reduce the surface roughness or subsequent cell attachment.

Acrylic Resins↗
PubMed1982

A comparative study of enzymes involved in glucose phosphorylation in oral streptococci.

The properties of two enzymes involved in the phosphorylation of glucose were studied in three oral streptococci species. The glucokinase of Streptococcus mutans had a lower affinity for glucose and ATP than did those from S. salivarius and S. sanguis. The enzyme had an identical pH optimum (pH 8.0) in all three bacteria. However, the result from the phosphoenolpyruvate phosphotransferase system showed a different pattern when its activity was measured using 2-deoxyglucose with toluenized cells. Uptake studies of 2-deoxyglucose also revealed that the three microorganisms had different affinities for this compound. This glucose analogue strongly inhibited the acid production of S. salivarius, but did not affect the glycolysis of the other two bacteria.

Glucokinase↗
PubMed1991

Alterations in oral microflora and pathogenesis of acute oral infections during remission-induction therapy in patients with acute myeloid leukaemia.

To investigate changes in the aerobic and facultatively anaerobic oral microflora during remission-induction chemotherapy in patients with acute myeloid leukaemia, 10 consecutive patients were studied during a period of 28 days. During antineoplastic treatment, the concentration of microorganisms in saliva doubled from day 0 to day 2, presumably as a result of a concurrent 64% decrease in the salivary flow rate. No changes in the relative proportion of individual microorganisms or acquisition of new microorganisms occurred during antineoplastic treatment. During antibacterial treatment, which was subsequently initiated in all patients, a 100-fold decline occurred in the median salivary concentration of microorganisms within the first 7 days. During this period, members of the normal flora became undetectable in 5 patients, and Enterobacteriaceae, Enterococcus faecalis or Candida spp. became parts of the quantitatively predominant oral microflora in 7 patients. Apart from Candida spp., these potentially pathogenic microorganisms were acquired only after the initiation of the antibacterial treatment. After termination of the antibacterial treatment, the median concentration of microorganisms increased again to the original level and normal flora became reestablished within a period of 8 days. Clinically, 10/20 acute oral infections emerged before day 8, i.e. within the period with increased concentrations of microorganisms in saliva. Specifically, the clinical diagnosis of acute oral candidiasis was associated with a rise in the concentration of Candida spp. above a critical value of 1,000 CFU/ml. Herpes simplex virus (HSV) type 1 was detected in 4/9 HSV-seropositive patients on days 14 and 21, and HSV-1 was in all 4 cases isolated simultaneously with the emergence of an intraoral ulcer. The results suggest that chemotherapy-induced xerostomia plays a significant role in the pathogenesis of acute oral infections and transmission of potentially pathogenic microorganisms is of importance mainly after initiated antibiotic treatment in these patients.

Aclarubicin↗
PubMed1999

Relationships between activity of daily living, and oral cavity care and the number of oral cavity microorganisms in patients with cerebrovascular diseases.

We examined the relationships among the activity of daily living (ADL), oral cavity care, and the number of oral cavity microorganisms in 40 patients with cerebrovascular diseases (CVD). The CVD patients were classified into 4 groups, I, II, III and IV based on their ADL and the method used for oral cavity care. The ADL was highest in group I and lowest in group III. Only the patients of only group III could not eat by themselves and were receiving naso-esophageal feeding. Oral cavity care was performed by the patients themselves in groups I and IV, but was performed by caregivers in groups II and III. The group IV patients had no teeth, but could eat by themselves using full dentures. The numbers of microorganisms in the pharyngeal swabs from the 4 groups were measured and expressed as colony-forming units (cfu). The numbers of both Staphylococci spp. and Candida spp. were significantly higher in group III than in the other groups. Moreover, Pseudomonas aeruginosa was isolated only from patients of group III (in about 66%). The oral cavity care by caregivers was almost the same in groups II and III, but the numbers of oral cavity microorganisms were significantly higher in group III than in group II. These results indicated that microorganisms grow more easily in the oral cavities of CVD patients with low ADL compared with CVD patients with higher ADL, and that eating is thought to be important for the prevention of an increase of microorganisms in the oral cavity.

Activities of Daily Living↗
PubMed2005

Archwire ligation techniques, microbial colonization, and periodontal status in orthodontically treated patients.

Fixed or removable orthodontic appliances impede the maintenance of oral hygiene and result in plaque accumulation. Plaque retention surrounding orthodontic appliances leads to enamel demineralization caused by organic acids produced by bacteria in the dental plaque. Many studies have evaluated the effects of fixed orthodontic appliances on microbial flora and periodontal status, but only a few have evaluated the method of ligation as an additional factor. The aim of this study was to determine the changes in microbial flora and periodontal status after orthodontic bonding and to determine whether two different archwire ligation techniques affect these changes. A total of 21 orthodontic patients scheduled for fixed orthodontic treatment were selected for this split-mouth study. Two commonly used auxiliaries (elastomeric rings and ligature wires) for tying archwires were tested. Microbial and periodontal records were obtained before bonding (T0), one week later (T1), and five weeks after bonding (T2). Paired t-test and Wilcoxon signed rank test were used to compare the groups statistically. Although, teeth ligated with elastomeric rings exhibited slightly greater numbers of microorganisms than teeth ligated with steel ligature wires, the differences were not statistically significant and could be ignored. The two archwire ligation techniques showed no significant differences in the gingival index, bonded bracket plaque index, or pocket depths of the bonded teeth. However, teeth ligated with elastomeric rings were more prone to bleeding. Therefore, elastomeric ring use is not recommended in patients with poor oral hygiene.

Adolescent↗
PubMed1989

A review of interstitial pneumonia in cattle.

Interstitial pneumonias comprise a significant proportion of cattle respiratory diseases. Known by different names, such as acute bovine pulmonary emphysema and edema (ABPE), fog fever, atypical interstitial pneumonia (AIP) and cow asthma, the condition seems to occur predominantly in late summer or fall. However, depending on the etiology, cases have occurred throughout the year. Interstitial pneumonia often begins with acute respiratory distress in animals that were clinically normal 12 hr earlier. Animals are observed breathing very rapid and shallow with their mouths open. If disturbed, death may occur rapidly from hypoxia. Causes of interstitial pneumonia are quite varied ranging from parasitic, viral and bacterial to toxic. Toxic agents constitute the most economically important cause of this condition in cattle. The primary toxin is the amino acid L-tryptophan in lush pasture grasses, a compound which is converted to 3-methylindole by rumen microorganisms. Other leading toxic causes of interstitial pneumonia are perilla mint and moldy sweet potatoes. Although treatments are mainly symptomatic and ineffective, preventive measures will reduce the occurrence of interstitial pneumonia. Prevention consists of denying animals exposure to know pneumotoxic agents, eliminating certain rumen microflora that break down the toxic compounds to reactive metabolites, and supplying ample good forage so that cattle will not as likely consume toxic plants.

Animals↗
PubMed1982

The normal human anaerobic microflora.

Anaerobic bacteria are prevalent among the bacterial populations of the human body, particularly on mucous membrane surfaces. The major sites with a rich anaerobic normal microflora are the mouth, the gastrointestinal tract and the female genital tract. The oral cavity harbours more than 300 different bacterial species. The concentrations of bacteria in saliva are 10(8) to 10(9) colony forming units/ml and anaerobic bacteria outnumber aerobic bacteria by 10:1. On the tooth surfaces, the concentrations of bacteria are 10(10) to 10(11) cfu/ml with a predominance of anaerobes. Bacterial concentrations in gingival scrapings are 10(11) to 10(12) cfu/ml with anaerobic bacteria outnumbering aerobic bacteria by 1000:1. In the saliva and on the tongue surface, the predominant anaerobic bacteria are cocci, while in the gingival crevice large concentrations of gram-negative rods are recovered. Microorganisms found in the upper intestinal tract are different from those in the lower intestinal tract. In the stomach and the proximal small bowel, the microorganisms found as normal flora are a reflection of the oral flora. Bacterial concentrations in this region are 10(2)-10(5) cfu/ml intestinal content. In the colon, bacterial concentrations of 10(11)-10(12) cfu/g faeces are found. About 500 different bacterial species are recovered in the lower intestine. The most common anaerobic microorganisms are bifidobacteria, lactobacilli and bacteroides. Recent studies have used quantitative techniques for analyses of the vaginal flora and it has been found that anaerobic bacteria outnumber aerobic bacteria in the vagina by approximately 10:1. The most prevalent bacteria are peptococci, present in counts of 10(7)-10(8) cfu/ml. Lactobacilli, corynebacteria, eubacteria and bacteroides are also isolated.

Anaerobiosis↗
PubMed1995

Presence of Helicobacter pylori in the oral cavity, oesophagus, stomach and faeces of patients with gastritis.

The presence of Helicobacter pylori in the oral cavity (6 sites), oesophagus, stomach and bowel of 20 dyspeptic patients was investigated. Samples were cultured on three selective media and analyzed by 16S rDNA polymerase chain reaction (PCR) and southern hybridization. Helicobacter pylori DNA was detected by PCR from oral-cavity samples of three (20%) and from faeces samples of only one (7%) of the patients whose stomach biopsies were positive for Helicobacter pylori. When culture was used, the microorganism's rate of recovery from the oral cavity and faeces was 13% and 7%, respectively. One patient had a Helicobacter pylori-like organism in samples collected from the tongue and palate. Both strains were urease, catalase and oxidase positive and grew microaerophilically but were negative on PCR analysis. This demonstrates the possibility of false identification of Helicobacter pylori by use of routine enzyme reactions. Interestingly, specimens collected from the cheeks of three patients were positive for Helicobacter pylori by PCR analysis. This is the first instance of detection of this microorganism in the cheek.

Adult↗
PubMed1992

Gram-negative enteric bacteria in the oral cavity of leukemia patients.

We examined changes in the bacterial flora in hospitalized patients with leukemia. This study placed special emphasis on enteric microorganisms and their relation to the general status of the patient. One hundred thirty bacterial cultures from 16 leukemia patients and 16 control subjects, were obtained. The organisms were isolated on MacConkey agar and identified by the API-20E system. Enteric microorganisms were isolated from 62.2% of the leukemia patients as compared with 28% from the control group (p < 0.001). The enteric positive cultures were identified as Klebsiella (42.7%), Enterobacter (18.8%), and Pseudomonas (15.6%). In contrast to the negative cultures (1342), enteric microorganisms were cultured from 2948 specimens (p < 0.005).

Adult↗
PubMed2004

Efficacy of three surface disinfectants for dental radiographic films and gloves.

Contaminated radiographic films and gloves may transmit infectious diseases. Objective. To determine whether Pre Sept (NaDC), a sodium dichloroisocyanurate based disinfectant; Bronocide SP (AIP) an alcohol-phenol-iodine disinfectant and polyvinyl pyrrolidine iodine (PVPI) can be used to disinfect radiographic films and gloves. Study design. Radiographic films were contaminated with Candida albicans, Streptococcus mutans, Lactobacilli or saliva and placed in either 0.1, 0.25 or 0.5 NaDC for 1, 2 or 5 min; PVPI for 5 min or sprayed with AIP. Gloves contaminated with C. albicans, S. mutans or Lactobacilli were sprayed with AIP. After treatment the films and gloves were tested for viable microorganisms. Results. A 0.5% solution of NaDC killed all microorganisms after one-minute exposure. PVPI killed 99.8% and AIP spray between 95.8 and 99% of microorganisms. Conclusions. NaDC was the most successful disinfectant in the laboratory and clinical setting followed by PVPI and AIP.

Benzyl Alcohols↗
PubMed1989

Eikenella corrodens in the human oral cavity.

The prevalence and distribution of the putative periodontal pathogen Eikenella corrodens in the human oral cavity was examined. A total of 508 oral bacterial samples were taken from 10 periodontally healthy adults (PH), 11 adult periodontitis patients (AP), and 6 localized juvenile periodontitis patients (LJP). From each subject, samples of supra- and subgingival plaque were obtained from six to eight teeth as well as samples from buccal mucosa, lateral and dorsal surfaces of tongue, tonsil, and saliva. E. corrodens was cultured from 70% of healthy subjects and 100% of periodontitis patients. Dental plaque appears to be the main oral ecological niche of E. corrodens in PH subjects since it was found in, respectively, 26% and 31% of supra- and subgingival plaque samples and rarely found in other oral sites in these subjects. It was found in 59% of both supra- and subgingival plaque samples from AP subjects, as well as 48% and 64% of supra- and subgingival plaque samples of LJP subjects. In contrast to healthy subjects, E. corrodens was found on the buccal mucosa, tongue, tonsil and in the saliva of patients with periodontitis. The microorganism constituted, on average, 1% to 2% of the total cultivable bacteria in supra- and subgingival plaque samples. The prevalence of E. corrodens in plaque samples was higher in AP and LJP subjects and was significantly different from PH subjects. Within the AP group, the prevalence of E. corrodens in subgingival plaque is significantly higher from sites with GI greater than or equal to 2. These data suggest that E. corrodens is an indigenous oral microorganism which may be an opportunistic pathogen associated with gingival inflammation.

Adolescent↗
PubMedDate not supplied

[Characterization of relationships between pro- and eukaryotic cells under the conditions of intracellular symbiosis of Staphylococcus aureus in the mucosa cells of the respiratory and digestive systems organs in terms of ecology and morphology].

The ecological and morphological analysis of reorganization processes in the cell and tissue structures of the mucous membranes of the respiratory and digestive systems in rats under the conditions of their prolonged symbiotic interactions with staphylococci (in the body of rats as a whole, as well as on the model of organotypic cultures in diffusion chambers in vivo) was carried out with the use of light and electron microscopy, radioautography and morphometry. The morphological equivalents of phenotypic reactions in the cell elements of the mucous membranes of the respiratory and digestive systems (epitheliocytes, leimyocytes, endotheliocytes, macrophages and fibroblasts) under the conditions of staphylococcus persistence were revealed. Adaptive and reactive shifts in eukaryotic cells were manifested by an increased volume of nuclei and greater proportion of euchromatin and a decreased DNA-synthetic and proliferative activity. Microorganisms located inside the cells underwent ultrastructural reorganization.

Adaptation, Physiological↗
PubMed1980

Genital flora during pregnancy and colonization of the newborn.

A longitudinal study of the cervical and vaginal microflora of 131 pregnant women showed a similar range of organisms at first visit (up to 16 weeks), at 28 weeks and at 36 weeks of pregnancy. Twenty different groups or genera of microorganisms were recovered, predominantly lactobacilli. There was a fall in the isolation rate of organisms in the mothers 6 to 8 weeks after delivery. Lactobacilli and yeasts including Candida albicans were recovered less frequently whereas the incidence of Escherichia coli and group B streptococci increased.Infants born to these mothers were swabbed within 24 hours of delivery and yielded organisms from the umbilicus, ear and mouth in 24%, 33% and 38% of cases respectively. Alpha haemolytic streptococci and Staphylococcus aureus were the predominant organisms. Sixteen different groups or genera were isolated.The isolation rates in non-pregnant women attending a `well-women' clinic were similar to those in the postnatal mothers; few women of 60 years or more were colonized.

Adult↗
PubMedDate not supplied

[Opportunistic microorganisms in respiratory tract diseases in patients of the Moscow Province region].

The respiratory tract microflora in patients with inflammatory processes of the upper and lower respiratory tracts in the Moscow Province region has been studied. Changes in the microflora were found to occur in patients with pyoinflammatory diseases (PID) of the upper and lower respiratory tracts have been found to occur. Gram-positive cocci, mainly staphylococci and streptococci, were shown to play the leading etiological role in the development of PID. As revealed in this study, the microorganisms detected in the inflammations of the upper and lower respiratory tracts are coagulase-negative staphylococci, mainly S. epidermidis, as well as enterococci and streptococci belonging to the group viridans.

Bacteria↗
PubMed1991

[The effect of magnetic retainers used in dental prostheses on the pathogenic microorganisms in the oral flora].

Patents for magnetic denture retainers in dental prosthesis, have issued since 1930, but recent developments rekindled interest. There have been many studies reporting the effects of magnetic fields on humans, animals, insects, tissue cultures, micro-organisms and enzymes. In some of these reports, damaging tissue effects were observed. In our study, the effect of these magnets to the growth of pathogen microorganisms found in oral flora were investigated with 2 different microbiological methods. In either of these methods, it was determined that the magnetic field didn't affect the colonization of bacteria.

Bacteria↗
PubMed1990

[Role of Actinobacillus actinomycetemcomitans in human infection].

Actinobacillus actinomycetemcomitans (AA), is a cocobacillus thin and small, non motile, uncapsulate and capnophilic. AA, is: one of the species encountered in the mouth's comensal flora being able to be isolated in gingival crevices culture and oral mucosa in a 20% of the healthy population. An important number of pathogenic factors make it well equipped, to protect itself from host's defense mechanisms, and to destroy the periodontal tissue. Between the most important we find lipopolisacarides and leucotoxines which promote tisular invasion and destructive qualities of this microorganism. Since 1912, there are numerous reports of infectious process associated to it, between which we find: endocarditis in native and prothesic valve, soft tissues abscess, pneumonia, brain's abscess, urethritis, vertebral osteomielitis, thyroid's abscess, pericarditis and periodontal juvenile illness, being this one in which its isolation is more frequent. In vitro, AA is very susceptible to tetracicline. This antibiotic reaches high concentrations in gingival crevices, has significant affinity to the alveolar bone and contributes to protect the collagen. These special feature make them the election drug in periodontal disease produced by this microorganism.

Actinobacillus↗
PubMed2000

Presence of microorganisms on the fitting denture complete surface: study 'in vivo'.

It was the intention to study if glazing the fitting surface of maxillary dentures with a light-curing acrylic resin would diminish the bacterial counts. The study included the application of a photopolymerizing glaze to one half of the fitting denture surface; after 15 days microbial plaque was collected from a 1 cm2 area of the glazed and the untreated resin, respectively. At the same time bacteria were collected from a 1 cm2 area of the corresponding sites on the palatal mucosa. The application of the glaze had modified the number of bacteria cultured from the glazed surface versus the untreated surface. Denture surface: total aerobic bacteria, 1:4; aerobic streptococci, 1:4; aerobic staphylococci, 1:5; anaerobic bacteria, 1:3.5; mucosal surface aerobic bacteria, 1:4; streptococcal, 1:4. The differences were statistically significant at P<0.002. However, from a quantitative and qualitative point of view these differences were minor compared with the actual concentrations of the microorganisms of 104-106/cm2 observed on the fitting denture surface and the palatal mucosa.

Acrylic Resins↗