Corticosteroids and oral candidosis.
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Administration, Oral↗
Biomedical subjects
D Beighton
Publications and source records attributed to D Beighton.
Detecting mannosidase activities using ribonuclease B and matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
Ribonuclease (RNase) B incubated with purified enzymes, whole bacterial cultures, or their separated components-cells and supernates-have been directly analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF) to detect exomannosidases and to evaluate their specificities and location. Enzymatic cleavage was monitored by observing changes in RNase B glycoform population. Thus a nonspecific alpha-(1 --> 2)-mannosidase activity converts the glycoprotein to its Man(5) form, identifiable by its mass of 14,899 [M + H](+); this species subsequently is converted, by the actions of alpha-(1 --> 3) and alpha-(1 --> 6)-mannosidases, to the Man(1) form via Man(4), Man(3), and Man(2). The Man(1) glycoform (which is readily isolated) has then similarly been used for identifying beta-(1 --> 4)-mannosidase and the derived Man(0) form has served in turn as a natural substrate for beta-(1 --> 4) N-acetylglucosaminidase producing a species possessing a single asparagine-linked GlcNAc residue (mass 13,886). Mannose liberated from the actions of mannosidases can, if desired, be quantified by, for example, chromatography. The actions and specificities of endoglycosidases such as a peptide-N-glycosidase F (PNGase F) and of endo-N-acetlyglucosaminidases (e.g., endo-F and endo-H), which respectively cleave between the GlcNAc&bond;Asn and GlcNAc&bond;GlcNAc bonds of N-linked glycoproteins, are also demonstrable by MALDI-ToF analysis of RNase B (and derived products). From these digests the completely deglycosylated polypeptide corresponding to RNase A in which Asn has been converted to Asp (mass 13,684) and a species corresponding to RNase A + GlcNAc (mass 13,886) are produced, together with their corresponding free oligosaccharides which are amenable to analysis by both MALDI-ToF and by HPLC.
Amidohydrolases↗
An evaluation of an oral health training programme for carers of the elderly in residential homes.
OBJECTIVE: The objectives of this study were: to evaluate carers' knowledge of oral health; to provide a high quality, consistent, oral health training programme for carers in residential homes; to evaluate the quality of this programme by examining both carers' changes in knowledge and any changes in carers' behaviour as reported by residents and to assess any changes in the oral health of the elderly residents after one year. DESIGN: A cross-sectional, multi-centre study using a carer training programme, evaluated by both a questionnaire conducted with carers and residents and oral examination of residents. SETTING: In August 1996, 20 (20%) of the residential/nursing homes, in West Hertfordshire were chosen at random and all managers contacted and offered an oral examination for all their residents. Ten (10%) of the homes were also offered an oral health training programme for their carers. Eighteen homes accepted the oral examination for all consenting residents and 7 of the 10 homes offered accepted the carer training. SUBJECTS: Thirty-nine carers from 7 of the residential homes attended an oral health training course and 213 elderly residents in the 18 homes were examined both at baseline and after 12 months. RESULTS: Carers' baseline knowledge about oral health was poor; the oral health training programme was enjoyed and their knowledge gain after one week was high. However, the elderly residents perceived no change in the oral care given by carers either after one week or after one year and there was no measurable improvement in the oral health of residents after carer training, except for an increase in filled coronal surfaces. Few of the carers originally trained were still working in the same residential homes after one year. CONCLUSION: Although the carer training programme was well received, no changes in oral health practice resulted. Barriers to practice of oral care by carers remained and training, even when including practical skills, evaluation by peers and a high knowledge gain, failed to reduce these barriers.
Aged↗
Caries-associated micro-organisms in infants from different socio-economic backgrounds in Scotland.
OBJECTIVES: The aims of this study were: (1) to compare the frequency of isolation of mutans streptococci, (Streptococcus mutans, Steptococcus sobrinus), lactobacilli and yeasts (caries-associated micro-organisms) in the saliva of 1-year-old infants with and without dental caries; and (2) to determine if socio-economic background influenced the frequency isolation of bacteria and caries status. METHODS: 1393 1-year-old consented infants, who comprised 70. 3% of children born in Dundee during a 1year period, had saliva samples taken (tongue-loop method) for microbiological culture and were examined for dental caries (d(1)-threshold: enamel and dentine diagnostic threshold). Thirty-nine infants were diagnosed with caries and the frequencies of isolation of caries-associated micro-organisms (and absolute microbial counts) were compared with infants who were caries-free. In addition, associations were sought between the infants' socio-economic background, the frequency of isolation of caries-associated micro-organisms and caries status. RESULTS: Streptococcus mutans, lactobacilli and yeasts were isolated more frequently from those infants with caries compared to those who were caries-free (S. mutans: 29.7 vs 9.8%, P=0.0008; lactobacilli: 15.4 vs 4.3%, P=0.0073; yeasts: 23.7 vs 10.4%, P=0.0016-Fisher's exact test). There were no significant differences between the isolation frequencies of S. sobrinus (2.7 vs 1.3%, P=0.39) from those with and without caries. Significantly, more infants living in areas of high deprivation had caries compared to those from more affluent areas (DEPCAT 6 and 7 vs 1-5: 3.6 vs 1.9%, P=0.049), but, apart from yeasts, socio-economic background was not significantly associated with the isolation frequencies of any of the caries-associated micro-organisms. CONCLUSIONS: In infants as young as 1year of age, salivary S. mutans, lactobacilli and yeasts but not S. sobrinus were isolated significantly more frequently from those with caries compared to those who were caries-free. Apart from yeasts, socio-economic background did not influence the frequency of isolation of caries-associated micro-organisms. However, infants living in areas of highest deprivation had significantly higher frequencies of caries compared to those from more affluent areas.
Colony Count, Microbial↗
Composition of the oral streptococcal flora in healthy children.
OBJECTIVES: To identify the predominant streptococcal species in the mouths of healthy children and to investigate the composition of the oral streptococcal flora over a period of 4 months. PATIENTS AND METHODS: The subjects were 33 fit, healthy schoolchildren aged between 5 and 16 years. These children were part of a large study and were the matched controls for a group of subjects undergoing bone marrow transplantation. The oral flora was sampled using an oral rinse technique on two separate occasions 4 months apart. The outcome measures were the number of each streptococcal species per millilitre of oral rinse; the isolation frequency of each species; the proportion of each species as a percentage of both the total streptococcal count and the total anaerobic count. RESULTS: The predominant species were Streptococcus salivarius, S. oralis and S. mitis. There was no significant variation in the composition of the oral streptococcal flora over the 4 month period. CONCLUSIONS: The oral rinse technique provides a reliable method of sampling the streptococcal flora of children.
Adolescent↗
The oral microbiota of children undergoing liver transplantation.
This study investigated the oral microbiota of children undergoing liver transplantation. Oral swabs were taken using a standardized procedure from 27 children before liver transplantation and at 3 and 100 days post-transplantation and from 27 healthy controls at baseline and 90 days. Viridans streptococci, yeasts, staphylococci, enterococci and Enterobacteriaceae were enumerated and identified using conventional techniques. The oral microbiota of the patients changed significantly immediately post-transplantation, but by the final examination, it had returned to baseline levels. The oral microbiota of the controls did not change significantly. The numbers and proportions of Streptococcus salivarius, Streptococcus sanguis and Streptococcus gordonii as percentages of the total streptococcal counts and of the total anaerobic counts decreased significantly 3 days post-transplantation (P < or = 0.006). There were no significant changes in the numbers and proportions of Streptococcus oralis and Streptococcus mitis isolated pre- and post-transplantation. The isolation frequencies and numbers of yeasts were significantly higher in patients than controls. Staphylococci were isolated in low numbers from all children. Enterococci and Enterobacteriaceae were isolated infrequently from patients.
Adolescent↗
Oral health in children undergoing liver transplantation.
AIMS: To determine the prevalence of dental caries in children undergoing liver transplantation and to compare the plaque, gingivitis, and gingival overgrowth indices and oral mucosal lesions in children before and after liver transplantation. PATIENTS AND METHODS: Patients undergoing liver transplantation at King's College Hospital were examined before transplantation, at 3 and 106 days post-transplantation. Healthy children from the Greenwich Health District, south-east London, were matched to the liver transplant patients by age, gender, socio-economic factors and the presence or absence of active dental caries. RESULTS: Twenty-seven liver transplant patients (mean age: 7 years and 10 months; SD 3 years and 5 months) and 27 controls (mean age: 8 years and 6 months; SD 3 years and 7 months) were examined. The mean dmft and DMFT scores were 2.3 (SD 4.1) and 0.8 (SD 1.4), respectively, in the liver transplant patients, and 1.2 (SD 2.2) and 0.9 (SD 1.5), respectively, in the controls. There were no significant differences between either the mean plaque or gingivitis indices for the primary and permanent teeth in patients before and after transplantation. There were no significant differences between the liver transplant patients and the controls for either mean plaque or gingivitis indices at each examination time. Gingival overgrowth was present in 41% of liver recipients receiving cyclosporin with or without nifedipine, but not in the majority receiving tacrolimus at the final examination. Oral mucosal lesions were absent in both the patients and controls at each examination time. CONCLUSIONS: The oral health of the children undergoing liver transplantation was inadequate. Funding and implementation of an oral health care programme must become a priority for all children before and after liver transplantation.
Adolescent↗
Isolation and characterisation of sialidase from a strain of Streptococcus oralis.
Streptococcus oralis, the most virulent of the viridans streptococci, produces a sialidase and this exo-glycosidase has been implicated in the disease process of a number of pathogens. The sialidase of S. oralis strain AR3 was purified in order to understand the characteristics of this putative virulence determinant. The enzyme isolated as a high mol. wt aggregate (c. 325 kDa) was purified 4520-fold from late exponential phase cultures by a combination of ultrafiltration, ammonium sulphate precipitation, ion-exchange and gel filtration chromatography. The sialidase component had a mol.wt of 144 kDa as determined by SDS-PAGE analysis. The purified sialidase released N-acetylneuraminic acid from a range of sialoglycoconjugates including human alpha1-acid glycoprotein, bovine submaxillary mucin, colominic acid and sialyl-alpha2,3- and sialyl-alpha2,6-lactose. Also, N-glycolylneuraminic acid was cleaved from bovine submaxillary mucin. The sialidase had a Km of 11.8 microM for alpha1-acid glycoprotein, was active over a broad pH range with a pH optimum of 6.0 and cleaved alpha2,3-, alpha2,6- and alpha2-8-sialyl glycosidic linkages with a marked preference for alpha2,3-linkages. The enzyme was competitively inhibited by the sialic acid derivative, 2,3-dehydro-N-acetylneuraminic acid, with a K(IC) of 1.2 microM. The characteristics of the purified sialidase would support a nutritional role for this enzyme that may be significant in the proliferation of this organism in the oral cavity and at extra-oral sites in association with life-threatening infections.
Chromatography, Gel↗
Mechanisms of resistance to quinupristin-dalfopristin among isolates of Enterococcus faecium from animals, raw meat, and hospital patients in Western Europe.
Twenty-eight quinupristin-dalfopristin-resistant isolates of Enterococcus faecium from hospital patients and nonhuman sources in European countries were studied. High-level resistance (MICs, >/=32 microg/ml) was associated with the presence of vat(E) (satG) (14 isolates ¿50%) or vat(D) (satA) (6 isolates ¿21%). These genes were not detected in eight (29%) isolates with lower levels of quinupristin-dalfopristin resistance (MICs, 4 to 16 microg/ml). This suggests the presence of further mechanisms of resistance to quinupristin-dalfopristin in E. faecium.
Acetyltransferases↗
Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque.
The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.
Dental Plaque↗
Production of an endo-beta-N-acetylglucosaminidase activity mediates growth of Enterococcus faecalis on a high-mannose-type glycoprotein.
Enterococcus faecalis is associated with a high proportion of nosocomial infections; however, little is known of the ability of this organism to proliferate in vivo. The ability of RNase B, a model glycoprotein with a single N-glycosylation site occupied by a family of high-mannose-type glycans (Man(5)- to Man(9)-GlcNAc(2)), to support growth of E. faecalis was investigated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of RNase B demonstrated a reduction in the molecular mass of this glycoprotein during bacterial growth. Further analysis by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry revealed that this mass shift was due to the degradation of all high-mannose-type glycoforms to a single N-linked N-acetylglucosamine residue. High-pH anion-exchange chromatography analysis during exponential growth demonstrated the presence of RNase B-derived glycans in the culture supernatant, indicating the presence of an endoglycosidase activity. The free glycans were eluted with the same retention times as those generated by the action of Streptomyces plicatus endo-beta-N-acetylglucosaminidase H on RNase B. The cleavage specificity was confirmed by MALDI-TOF analysis of the free glycans, which showed glycan species containing only one N-acetylglucosamine residue. No free glycans were detectable after 5 h of bacterial growth, and we have subsequently demonstrated the presence of mannosidase activity in E. faecalis, which releases free mannose from RNase B-derived glycans. We propose that this deglycosylation of glycoproteins containing high-mannose-type glycans and the subsequent degradation of the released glycans by E. faecalis may play a role in the survival and persistence of this nosocomial pathogen in vivo.
Carbohydrate Sequence↗
Attitudes of carers and the elderly occupants of residential homes to antimicrobial chewing gum as an aid to oral health.
OBJECTIVE: The aim of this study was to investigate the attitudes of elderly residents to using an antimicrobial chewing gum as an aid to oral health, and the opinion of their carers on such a procedure. DESIGN: A cross-sectional, multi-centre survey using a structured interview/questionnaire conducted with elderly residents and their carers. SETTING: In January 1998, 9 residential/nursing homes were chosen at random from all the homes in West Hertfordshire, 207 residents were asked to chew two pieces of gum twice daily for 7 days. SUBJECTS: The participants, 148 women and 59 men, were aged between 53-100 years (mean age 82.23 +/- 9.62 years). 47 carers, all female, were involved in distributing and collecting the gum. RESULTS: 122 residents (58.9%) were edentulous and 85 (41%) of the participants were partially dentate. Of those with teeth 23 (27%) had 21 teeth or more. 73 (35.2%) residents found that chewing the gum was difficult with 37 (17.9%) of this group being unable to chew (P < 0.0001 for those residents with no teeth/dentures or dentures unopposed by teeth or other dentures). 32 (18.6%) subjects disliked the flavour of the gum. Of the 170 residents who chewed the gum 99 (57.2%) found it reduced oral dryness and 78 (45.1%) reported it made their mouth feel healthy. 34 (53.6%) of the dentate and 47 (40.9%) of the edentate residents wished to keep using the gum (P < 0.05). 35 (74.5%) of the carers found it easy to distribute the gum and 29 (61.7%) thought that chewing gum was an acceptable method of maintaining oral health for residents. CONCLUSION: The antimicrobial gum investigated in this study was acceptable to many elderly occupants and their carers, significantly improving perceived oral health and oral dryness of residents.
Aged↗
Oral health of elderly occupants in residential homes.
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Aged↗
The effect of xylitol and chlorhexidine acetate/xylitol chewing gums on plaque accumulation and gingival inflammation.
Chewing gums may be suitable vehicles for the delivery of xylitol (X) and chlorhexidine acetate (CHX), both of which can aid oral health. The aim of this study was to determine the clinical effectiveness of chewing gums containing X or a combination of X and CHX in a double-blind, randomised, cross over, 5-day clinical trial, with a 9-day washout period in a group of participants over 40 years old. After professional tooth cleaning, 8 subjects (mean age 51.3+/-10.4 years) used in a random order 2 pieces of ACHX (a liquorice flavoured CHX/X) gum, 2 pieces of BCHX (a chocolate mint flavoured CHX/X), 2 pieces of X (a liquorice flavoured X gum) and 1 piece of ACHX. Gums were chewed 2x daily for 15 min and volunteers refrained from all other oral hygiene procedures. Data were analysed using Friedman nonparametric analysis of variance. Plaque indices for chewing 2 pieces of ACHX gum (0.78+/-0.15) and BCHX gum (0.52+/-0.15) were significantly lower (p<0.0006) than for X gum (1.57+/-0.08). The gingival index was significantly greater (p<0.05) for X containing gum than for the other chewing regimes. The subjects' attitudes to the gums were also assessed by structured questionnaires which showed that all gums were easy to chew, did not adhere to dentures, teeth or restorations and that the subjects preferred to chew 2 pellets rather than 1.
Analysis of Variance↗
The pattern of change in salivary immunoglobulins and antibodies to S. mitis and S. oralis in children undergoing bone marrow transplantation: use of an indirect method of assessment.
The objective of this study was to assess the pattern of change in salivary immunoglobulins and antibodies to S. mitis and S. oralis in 23 children following allogeneic bone marrow transplantation and their matched controls. To overcome the difficulty of obtaining a sufficient quantity of whole saliva from very young, sick children saliva was collected in a 5-ml oral rinse of sterile normal saline. It was not possible to measure the volume of whole saliva in each rinse and the concentration of the salivary immunoglobulins and bacterial antibodies were estimated from 1 ml of oral rinse. Despite these shortcomings a pattern of change in the mean concentrations of total salivary IgA, secretory IgA, antibodies to S. mitis and S. oralis and total IgG at specific event- related times during the transplantation period has been demonstrated. There was a significant increase in the concentration of salivary IgG 7 days post-transplantation, followed by significant decreases in total salivary IgA, secretory IgA and antibodies to S. mitis after recovery of the peripheral neutrophil count above 0.5 x 10(9). The concentrations of total IgA and antibodies to S. oralis was significantly greater in the transplant group 119 days post-transplantation.
Antibodies, Bacterial↗
Sequential deglycosylation and utilization of the N-linked, complex-type glycans of human alpha1-acid glycoprotein mediates growth of Streptococcus oralis.
Streptococcus oralis is the agent of a large number of infections in immunocompromised patients, but little is known regarding the mechanisms by which this fermentative organism proliferates in vivo. Glycoproteins are widespread within the circulation and host tissues, and could provide a source of fermentable carbohydrate for the growth of those pathogenic organisms with the capacity to release monosaccharides from glycans via the production of specific glycosidases. The ability of acute phase serum alpha1-acid glycoprotein to support growth of S.oralis in vitro has been examined as a model for growth of this organism on N-linked glycoproteins. Growth was accompanied by the production of a range of glycosidases (sialidase, N-acetyl-beta-D-glucosaminidase, and beta-D-galactosidase) as measured using the 4-methylumbelliferone-linked substrates. The residual glycoprotein glycans remaining during growth of this organism were released by treatment with hydrazine and their analysis by HPAEC-PAD and MALDI demonstrated extensive degradation of all glycan chains with only terminal N-acetylglucosamine residues attached to asparagines of the protein backbone remaining when growth was complete. Monosaccharides were released sequentially from the glycans by S.oralis glycosidases in the order sialic acid, galactose, fucose, nonterminal N-acetylglucosamine, and mannose due to the actions of exo-glycosidic activities, including mannosidases which have not previously been reported for S.oralis. All released monosaccharides were metabolized during growth with the exception of fucose which remained free in culture supernatants. Direct release of oligosaccharides was not observed, indicating the absence of endo-glycosidases in S.oralis. We propose that this mechanism of deglycosylation of host glycoproteins and the subsequent utilization of released monosaccharides is important in the survival and persistence of this and other pathogenic bacteria in vivo.
Carbohydrate Sequence↗
A study of small-colony, beta-haemolytic, Lancefield group C streptococci within the anginosus group: description of Streptococcus constellatus subsp. pharyngis subsp. nov., associated with the human throat and pharyngitis.
beta-Haemolytic, Lancefield group C streptococci within the anginosus-species group were shown by genetic and phenotypic criteria to be heterogeneous and to constitute two distinct taxa related at subspecies level to Streptococcus constellatus and Streptococcus anginosus, respectively. The first group, referred to here as DNA group 1, comprised six strains with 86-100% intragroup overall genomic DNA relatedness; five of the strains were originally isolated from the human throat and one was from an abdominal mass. They shared 61-77% DNA relatedness (delta Tm values = 1.2-1.5 degrees C) with reference strains of S. constellatus and were clearly differentiated from S. constellatus (now named Streptococcus constellatus subsp. constellatus) by the ability to produce beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, beta-D-fucosidase, beta-D-galactosidase and beta-D-glucosidase. The name S. constellatus subsp. pharyngis is proposed for these strains on the grounds that they are genetically and phenotypically distinct and exhibit a predeliction for the human throat, being isolated also from cases of pharyngitis. The DNA G + C content is 35-37 mol%. The type strain is MM9889aT (= NCTC 13122T). The second group (DNA group 2) was formed by five beta-haemolytic, Lancefield group C strains originally isolated from various human infections. DNA group 2 strains (81-100% intragroup DNA relatedness) shared 60-72% DNA relatedness (delta Tm values = 2.1-4.1 degrees C) with S. anginosus strains NCTC 10713T and MAS 283 but were not clearly differentiated phenotypically from S. anginosus, showed no clear pattern of clinical association, and therefore are not formally proposed as a new subspecies here.
Bacterial Typing Techniques↗
N-acetylneuraminic acid transport by Streptococcus oralis strain AR3.
Streptococcus oralis has emerged as one of the most important organisms of the viridans streptococcus group in terms of infections and is recognised as an agent of infective endocarditis and, in immunocompromised patients, septicaemia. The mechanisms by which this organism proliferates in vivo are unknown. However, host-derived sialic acids -- including N-acetylneuraminic acid (NeuNAc) which is present in serum and cell-associated glycoproteins -- are a potential source of fermentable carbohydrate for bacterial proliferation, especially for sialidase-producing bacteria, including S. oralis. To further elucidate the role of NeuNAc in supporting growth, this study determined the ability of S. oralis strain AR3 (isolated from a patient with infective endocarditis) to transport NeuNAc and characterised the transport system. The transport of [14C]-labelled NeuNAc into S. oralis was monitored and this transport system was induced by growth of the bacteria in the presence of the N-acetylated sugars NeuNAc, N-acetylglucosamine and N-acetylmannosamine. The transport system followed typical Michaelis-Menten kinetics, with a Km of 21.0 microM and a Vmax of 2.65 nmoles of NeuNAc transported/min/mg of dry cell mass. NeuNAc transport was inhibited by the presence of exogenous N-glycolylneuraminic acid, a related sialic acid. Chlorhexidine, NaF and 2,4-dinitrophenol were potent inhibitors of the transport system, suggesting that the uptake of NeuNAc occurs via a proton motive force-dependent permease system. This is the first report of the mechanism by which NeuNAc transport occurs in pathogenic streptococci. This transport process may have relevance to the acquisition of a source of fermentable carbohydrate and thus bacterial proliferation in vivo.
2,4-Dinitrophenol↗