muramidase has been researched along with thiocyanate* in 15 studies
2 trial(s) available for muramidase and thiocyanate
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The effects of glycopyrrolate on oral mucous host defenses in healthy volunteers.
We studied the effects of glycopyrrolate on oral mucous host defenses. Single IV doses of glycopyrrolate (4 microg/kg) or placebo were administered to 12 healthy volunteers in a randomized, double-blinded, cross-over study. Salivary flow rates and the concentrations/activities of total protein, amylase, and nonimmunologic (lysozyme, lactoferrin, myeloperoxidase, total salivary peroxidase, and thiocyanate) and immunologic (total immunoglobulin A, immunoglobulin G, and immunoglobulin M) mucous host defense factors were determined for paraffin-stimulated whole saliva before and 1, 3, 6, 12, 24, and 48 h after drug administration. Glycopyrrolate serum concentrations were determined before and 2, 4, 6, 10, 15, and 30 min and 1, 2, 3, 6, 12, and 24 h after IV drug injection. Salivary flow rates were decreased significantly for 12 h after glycopyrrolate injection, compared with saline injection. The concentrations of immunologic and nonimmunologic defense factors were increased in the glycopyrrolate group, and differences between the groups were found for all factors (P < 0.05-0.001) except lysozyme and total salivary peroxidase. In contrast, because of the reduced flow rate, the output of all defense factors into the saliva was decreased after glycopyrrolate injection, compared with saline injection. Glycopyrrolate thus decreases the output of salivary host defense factors into the oral cavity.. Glycopyrrolate induces long-lasting hyposalivation and decreases the secretion of salivary immunologic and nonimmunologic defense factors in healthy volunteers. Topics: Adjuvants, Anesthesia; Adult; Amylases; Cross-Over Studies; Double-Blind Method; Glycopyrrolate; Humans; Immunoglobulins; Injections, Intravenous; Lactoferrin; Male; Mouth Mucosa; Muramidase; Peroxidase; Saliva; Salivary Proteins and Peptides; Thiocyanates | 2000 |
Comparisons of various salivary parameters in smokers before and after the use of a nicotine-containing chewing gum.
This study was designed to compare various salivary parameters between smokers and non-smokers and to determine the influence of a nicotine-containing chewing gum (used to aid in quit-smoking efforts) upon these same parameters. At the baseline examination, subjects were assigned to one of three groups: non-smokers who did not utilize any gum, smokers provided a nicotine-containing gum, and smokers provided a placebo gum. Saliva was collected from all subjects and analyzed for acidogenicity and buffer pH as well as for levels of thiocyanate, lactoperoxidase, lysozyme, lactoferrin, and secretory IgA. After 15 weeks of gum usage, saliva was again collected from each subject and the identical analyses performed. Significant differences were observed between smokers and non-smokers with regard to three parameters: The saliva of smokers contained greater concentrations of thiocyanate and lower concentrations of lactoferrin, at the baseline examination and after the 15-week test period. In addition, the CO content of alveolar air was higher in smokers at both examination periods. In contrast, the use of the nicotine gum per se had no effect on any of the test parameters. Topics: Adult; Carbon Monoxide; Chewing Gum; Humans; Hydrogen-Ion Concentration; Immunoglobulin A, Secretory; Lactoferrin; Lactoperoxidase; Muramidase; Nicotine; Saliva; Smoking; Thiocyanates | 1985 |
13 other study(ies) available for muramidase and thiocyanate
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Sensitivity of Helicobacter pylori to an innate defence mechanism, the lactoperoxidase system, in buffer and in human whole saliva.
Helicobacter pylori has frequently been isolated from human dental plaque, and oral spread via saliva is thought to be one of its principal modes of transmission. Among other innate defence systems human saliva contains peroxidase enzymes and lysozyme. The sensitivity of H. pylori to physiological concentrations of lactoperoxidase and its salivary substrate thiocyanate, and different amounts of hydrogen peroxide (H(2)O(2)) was investigated in buffer and in human whole saliva. The effect of lysozyme was also studied in saliva. All tested H. pylori strains, ATCC 43504(T) and five clinical isolates, were efficiently inhibited by the peroxidase system with high concentrations of H(2)O(2) in buffer. The inhibition was stronger at lower pH. However, in human saliva these high concentrations of H(2)O(2) generated less hypothiocyanite, the antibacterial product of the peroxidase system and the effects of the peroxidase system were weaker. Physiological concentration of lysozyme was not bacteriocidal against H. pylori, nor did it enhance the effect of the peroxidase system in saliva. Thus, further studies are needed to enhance the efficacy of peroxidase systems in human saliva to make it more beneficial not only against dental but also against gastric pathogens. Topics: Buffers; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen Peroxide; Lactoperoxidase; Muramidase; Saliva; Thiocyanates | 2004 |
Salivary analyses and caries increment over 4 years: an approach by cluster analysis.
Caries as a multifactorial process is influenced by salivary defense. Cluster analyses should give additional information on the role of salivary variables in relation to caries increment.. Samples of unstimulated and stimulated whole saliva from 28 young adults (mean age 23.5+/-2.1 years) were analyzed for flow rate, pH and buffer variables, lysozyme, lactoferrin, peroxidase, thiocyanate, secretory immunoglobulin A, and total protein. The decayed, missing, and filled surfaces (DMFS) were recorded at baseline and after 4 years. Cluster analyses were executed on the basis of salivary data.. The mean caries increment (DeltaDMFS) over 4 years was 6.7+/-4.0 (range 1-16). In two-cluster processing, three out of four volunteers with low caries increments were grouped into one cluster. Only a few variables proved to be important for cluster characteristics.. The results suggest that over 4 years (1) the volunteers with very low caries increment (DeltaDMFS=1) are classified always together, (2) these volunteers do not form a separate cluster by themselves, (3) low caries increment was related to higher salivary flow rate and lower levels of lysozyme and lactoferrin for unstimulated saliva and (4) the partial pressure of CO(2) was of importance in stimulated saliva. Topics: Adult; Buffers; Carbon Dioxide; Cluster Analysis; Dental Caries; DMF Index; Female; Humans; Hydrogen-Ion Concentration; Immunoglobulin A, Secretory; Incidence; Lactoferrin; Longitudinal Studies; Male; Muramidase; Partial Pressure; Saliva; Salivary Proteins and Peptides; Secretory Rate; Thiocyanates | 2004 |
[Do lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-hydrogen peroxide-system cause negative microbiological results in mastitis secretions?].
Lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-peroxide-system are naturally occurring antimicrobial components of milk. The objective of this study was to examine, whether these components were responsible for negative results, when mastitis milk is cultured microbiologically. Quarter milk samples from 75 cows with clinical mastitis on a dairy farm in Brandenburg were submitted for microbiological culture and analysed for the content and the activities of the three components. Animals from all stages of lactation with clinical mastitis were included in the study. Animals were examined clinically and milk samples were collected prior to first treatment. Secretions from quarters with clinical mastitis were compared to those of neighbouring quarters without clinical mastitis. Secretions with positive cultural results were compared to those with negative results. The concentrations or activities of the three factors were significantly higher in the diseased quarters than in the quarters without clinical signs of mastitis. The concentration of lysozyme increased with severity of the clinical signs (local swelling and changes in secretion). The concentration of lactoferrin was significantly higher in quarters with slight alterations of glandular tissue than in quarters with medium or severe alterations (P < 0.05). LPS-activities did not correlate with the severity of clinical signs. No differences in the concentration of lactoferrin or LPS-activities were seen between mastitis with positive and negative culture results. The concentration of lysozyme was even higher in culturally positive samples than in negative samples (P < 0.05). Results from this study indicate that the three factors examined did not impair the results of microbiological culture of milk samples from quarters with clinical mastitis. Topics: Animals; Cattle; Female; Fermentation; Hydrogen Peroxide; Lactoferrin; Lactoperoxidase; Mastitis, Bovine; Milk; Muramidase; Thiocyanates | 2002 |
Longitudinal analysis of the association of human salivary antimicrobial agents with caries increment and cariogenic micro-organisms: a two-year cohort study.
Previous studies of the possible associations of salivary antimicrobial agents with dental caries have given controversial results, obviously mainly because almost all studies have been cross-sectional. Our aim was to find out, in a two-year longitudinal follow-up study, the associations among selected salivary non-immune and immune antimicrobial variables, cariogenic bacteria, and caries increment. The study population was comprised of 63 subjects, all of whom had their 13th birthday during the first study year. In addition to a comprehensive dental examination at baseline and after 2 yrs, paraffin-stimulated whole saliva samples were collected in a standardized way at six-month intervals. Saliva samples were analyzed for flow rate, buffer effect, lysozyme, lactoferrin, total peroxidase activity, hypothiocyanite, thiocyanate, agglutination rate, and total and specific anti-S. mutans IgA and IgG, as well as for numbers of total and mutans streptococci, lactobacilli, and total anaerobic bacteria. Cluster analysis and Spearman-Rank correlation coefficients were used to explore possible associations between and among the studied variables. During the two-year period, a statistically significant increase was observed in flow rate, thiocyanate, agglutination rate, anti-S. mutans IgA antibodies, lactobacilli, and total anaerobes, whereas lysozyme, lactoferrin, and total and anti-S. mutans IgG antibodies declined significantly. Based on various analyses, it can be concluded that, at baseline, total IgG and hypothiocyanite had an inverse relationship with subsequent two-year caries increment, anti-S. mutans IgG antibodies increased with caries development, and mutans streptococci and lactobacilli correlated positively with both baseline caries and caries increment. Total anaerobic microflora was consistently more abundant among caries-free individuals. In spite of the above associations, we conclude that none of the single antimicrobial agents as such has sufficiently strong power to have diagnostic significance in vivo with respect to future caries. Topics: Adolescent; Agglutination; Anti-Bacterial Agents; Antibodies, Bacterial; Bacteria, Anaerobic; Buffers; Child; Cluster Analysis; Cohort Studies; Colony Count, Microbial; Cross-Sectional Studies; Dental Caries; DMF Index; Female; Finland; Follow-Up Studies; Humans; Immunoglobulin A, Secretory; Immunoglobulin G; Lactobacillus; Lactoferrin; Longitudinal Studies; Male; Muramidase; Peroxidases; Saliva; Secretory Rate; Streptococcus mutans; Thiocyanates | 1998 |
Stimulated salivary flow rate and composition in asthmatic and non-asthmatic adults.
The number of decayed, missed and filled permanent teeth (DMFT), the degree of periodontal inflammation (Periodontal Status Index, PSI), stimulated salivary flow rate and the concentrations of total protein, lactoferrin, lysozyme, myeloperoxidase, salivary peroxidase, calcium, potassium, sodium and thiocyanate in whole saliva of 26 adult asthma patients were compared with those of 33 non-asthmatic controls. The saliva was also analysed for mutans streptococci, lactobacilli, total anaerobic flora and Candida spp. The mean PSI (p < 0.05; 95% confidence interval for the difference between means (95% CI) 2.47-25.30) was higher and the mean stimulated salivary flow rate (p < or = 0.05; 95% CI 0.57-0.55) was lower in the asthmatic group than in the control group. No differences were found between the groups in non-immune defense factors, except for myeloperoxidase. The myeloperoxidase concentrations were higher in asthmatics than in non-asthmatics (p < 0.05; 95% CI 4.4-134.0 ng/ml). No differences in microbial counts were found. It was concluded that stimulated salivary flow rates decrease while myeloperoxidase concentrations increase in adult asthmatic patients compared with non-asthmatic adults. The higher concentrations of myeloperoxidase are explained by a higher PSI in asthmatics. Topics: Adult; Asthma; Bacteria, Anaerobic; Calcium; Candida; Colony Count, Microbial; Confidence Intervals; DMF Index; Female; Humans; Lactobacillus; Lactoferrin; Male; Middle Aged; Muramidase; Periodontal Index; Periodontitis; Peroxidase; Peroxidases; Potassium; Saliva; Salivary Proteins and Peptides; Secretory Rate; Sodium; Streptococcus mutans; Thiocyanates | 1998 |
Properties of whole saliva and dental plaque in relation to 40-month consumption of chewing gums containing xylitol, sorbitol of sucrose.
Samples of whole saliva and dental plaque were collected from initially 10-year old subjects who participated in a 40-month cohort study investigating the effect of chewing gum usage on caries rates. The subjects represented nine cohorts of which one did not receive gum, while in eight cohorts the subjects received gum containing either xylitol, sorbitol, their mixtures, or sucrose as bulk sweeteners, the maximum sweetener consumption in the form of gums being up to 10.7 g/day, used in 3-5 daily chewing episodes. Gum usage had no significant effect on the levels of salivary protein, IgA, alpha-amylase, peroxidase, lysozyme, SCN and buffer capacity. At the endpoint, the group that received 100% xylitol pellet-shaped gum five times/day, had significantly lower levels of sucrase (p <0.05) and free sialic acid (p < 0.001) in whole saliva than at baseline. This group showed significantly (p <0.05) smaller plaque index scores at two cross-sectional measurements, and exhibited the lowest log(10) counts of salivary lactobacilli at endpoint than most other groups. The salivary levels of peptidase(s) (oligopeptidase B-like enzymes) hydrolyzing N-alpha-benzoyl-DL-arginyl-p-nitroaniline were significantly (p<0.05) or almost significantly lower in groups which received 100% xylitol pellet gums. All groups exhibited obviously an aging-related increase of salivary mutans streptococcus scores, except the above xylitol group in which the mean scores did not change. Topics: alpha-Amylases; Aniline Compounds; Buffers; Cariostatic Agents; Chewing Gum; Child; Cohort Studies; Colony Count, Microbial; Cross-Sectional Studies; Dental Caries; Dental Plaque; Dental Plaque Index; Humans; Immunoglobulin A, Secretory; Lactobacillus; Muramidase; Peptide Hydrolases; Peroxidases; Saliva; Salivary Proteins and Peptides; Sialic Acids; Sorbitol; Streptococcus mutans; Sucrase; Sucrose; Sweetening Agents; Thiocyanates; Xylitol | 1996 |
Saliva composition in children and young adults with Papillon-Lefèvre syndrome.
The aim of the present study was to evaluate the salivary secretion rate and composition in a group of 16 children and young adults (6-27 years) with Papillon-Lefèvre Syndrome (PLS), and to compare the findings with a group (n = 16) of healthy controls. Unstimulated and stimulated whole saliva was collected at least 2 h after meals and the secretion rate determined. The stimulated saliva was assessed for buffer capacity, total protein, peroxidase and hexosamine, while the unstimulated samples were evaluated for total protein, lysozyme, thiocyanate, lactoferrin and salivary IgA. Both the unstimulated (p < 0.01) and stimulated (p < 0.05) saliva secretion rates were significantly lower among the PLS patients compared with the controls. Furthermore salivary buffer capacity was significantly (p < 0.01) lower in the PLS patients. The total protein content in saliva was comparatively high in the study group, while the concentrations of immunoglobulins and non-immunoglobulins were within normal ranges. When calculating the output of the assessed antimicrobial factors, the mean peroxidase level in stimulated whole saliva was found to be significantly (p < 0.01) lower in the PLS patients than in the healthy controls. In conclusion, the present study indicates an impaired water secretion and a somewhat altered saliva gland function in children and young adults with PLS. Topics: Adolescent; Adult; Case-Control Studies; Child; Child, Preschool; Female; Hexosamines; Humans; Immunoglobulin A, Secretory; Lactoferrin; Male; Muramidase; Papillon-Lefevre Disease; Periodontitis; Peroxidase; Saliva; Salivary Glands; Salivary Proteins and Peptides; Secretory Rate; Statistics, Nonparametric; Thiocyanates; Water-Electrolyte Balance | 1996 |
Concentrations of thiocyanate, hypothiocyanite, 'free' and 'total' lysozyme, lactoferrin and secretory IgA in resting and stimulated whole saliva of children aged 12-14 years and the relationship with plaque accumulation and gingivitis.
Resting and stimulated whole saliva was collected from 94 children aged 12-14 years and analyzed for thiocyanate, hypothiocyanite, 'free' and 'total' lysozyme, lactoferrin and secretory IgA. Clinical assessments of the amounts of plaque and gingival inflammation were made, and plaque was collected for determination of dry weight. An inverse relationship was observed between salivary thiocyanate concentrations in both resting and stimulated saliva and the amounts of plaque and gingival inflammation in these subjects (p < 0.05). Lactoferrin concentration in stimulated saliva was directly related to the amounts of plaque and gingivitis (p < 0.05). 'Total' lysozyme concentration in stimulated saliva was directly related to the amount of plaque (p < 0.05), and the 'free' lysozyme concentration in the same saliva was directly related to the amount of gingivitis (p < 0.05). The direct relationship observed between clinical measurements and both lysozyme and lactoferrin concentrations in saliva may have been due to contributions from gingival crevicular fluid. Cluster analysis identified three groups of subjects with different profiles in resting whole saliva, and in particular with different levels of secretory IgA. A statistically significant difference was observed in the quantity of plaque collected from subjects in two of these groups (p < 0.05). These results from cluster analysis using resting whole saliva from children confirmed the findings of a previous study with young adults. Topics: Adolescent; Child; Cluster Analysis; Dental Plaque; Gingivitis; Humans; Immunoglobulin A, Secretory; Lactoferrin; Multivariate Analysis; Muramidase; Saliva; Salivary Proteins and Peptides; Secretory Rate; Thiocyanates | 1993 |
Viability of Streptococcus mutans and Streptococcus sobrinus in whole saliva with varying concentrations of indigenous antimicrobial agents.
We have studied the possible relationship between indigenous salivary antimicrobial agents, indigenous mutans streptococci and the capability of added mutans streptococci to grow in saliva. Stimulated whole saliva was collected from 19 healthy donors. Saliva samples were sterilized, supplemented with glucose and inoculated with Streptococcus mutans or Streptococcus sobrinus. The mixtures were incubated for 20 h followed by counting of viable cells. Saliva samples were analysed, both before and after sterilization, for indigenous antimicrobial agents and the bacterial flora. The subjects could be divided into two groups: those (n = 9) whose saliva promoted and those (n = 10) whose saliva inhibited the growth of the inoculated streptococci. A statistically significant correlation (+0.82, p < 0.001) was found between the numbers of viable cells of S. mutans and S. sobrinus after incubation in saliva. The sterilization procedure reduced the content of all antimicrobial proteins. Salivary antimicrobial factors, or levels of indigenous mutans streptococci, did not differ between the two groups. We conclude that none of the individual salivary antimicrobial factors alone can explain the large individual differences in growth-promoting or growth-inhibiting patterns of saliva on S. mutans and S. sobrinus. Inter-individually, saliva either supports or inhibits the growth of mutans streptococci, indicating a similar response of these two species in relation to the properties of saliva. Topics: Adult; Anti-Bacterial Agents; Antibodies, Bacterial; Female; Humans; Hydrogen-Ion Concentration; Immunoglobulin A, Secretory; Immunoglobulin G; Lactoferrin; Male; Muramidase; Peroxidase; Peroxidases; Saliva; Sterilization; Streptococcus mutans; Streptococcus sobrinus; Thiocyanates | 1992 |
Lysozyme enhances the inhibitory effects of the peroxidase system on glucose metabolism of Streptococcus mutans.
The combined effect of the salivary peroxidase system and lysozyme on the glucose uptake of Streptococcus mutans NCTC 10449 was investigated. The bacteria were grown to late-exponential phase, washed, re-suspended in buffer at pH6, and incubated with (1) 50 micrograms/mL lysozyme from human milk for 60 min; (2) 7-15 mumol/L hypothiocyanous acid/hypothiocyanite for 10 min; and (3) lysozyme for 60 min prior to addition of and incubation with hypothiocyanous acid/hypothiocyanite for 10 min. Glucose uptake was initiated by adding the bacterial suspensions to 10 mL of pre-warmed 50 mumol/L glucose containing 0.98 mumol/L D-(U-14C-)-glucose, and the mixture was incubated in a shaking water-bath at 37 degrees C. Samples were withdrawn at various time intervals, rapidly filtered through 0.45-microns membranes, washed with ice-chilled buffer, and the incorporated radioactivity determined. Lysozyme stimulated S. mutans glucose uptake slightly, but significantly inhibited S. rattus glucose metabolism. A 20-30% inhibition of radiolabeled glucose incorporation was observed with hypothiocyanous acid/hypothiocyanite alone. Incubation of the bacteria with lysozyme prior to addition of hypothiocyanous acid/hypothiocyanite containing peroxidase resulted in a total inhibition of the glucose uptake. In contrast, lysozyme in combination with hypothiocyanous acid/hypothiocyanite without peroxidase gave only a 30-50% inhibition. The addition of 5 mmol/L dithiothreitol after incubation with lysozyme and hypothiocyanous acid/hypothiocyanite eliminated the inhibition of the bacterial glucose uptake. The viability of S. mutans was not affected by treatment with any of the components used. Our results indicate that physiological concentrations of lysozyme and the salivary peroxidase system components have a synergistic effect which results in a significant inhibition of glucose metabolism by S. mutans. Topics: Animals; Anti-Bacterial Agents; Carbon Radioisotopes; Drug Synergism; Glucose; Hydrogen Peroxide; Muramidase; Oxidation-Reduction; Rats; Salivary Proteins and Peptides; Streptococcus; Streptococcus mutans; Thiocyanates; Time Factors | 1992 |
Effect of smokeless tobacco use in humans on mucosal immune factors.
To assess the effects of smokeless tobacco on the secretory immune system and dental caries, we examined users of smokeless tobacco and non-tobacco users. There were no significant differences in the prevalence of DMFS between users and non-users. There was significantly more salivary IgA, IgA2 and J-chain in users. Levels of salivary lysozyme and lactoferrin were significantly lower in users than controls. Because there was no difference in levels of secretory component in relation to the increased IgA levels of smokeless tobacco users, this suggests an effect of smokeless tobacco on secretory epithelial cells responsible for synthesis of secretory component, lysozyme and lactoferrin, and for the packaging of secretory component on IgA. There were only slight differences in salivary or serum antibody levels to Streptococcus mutans. These findings indicate that although smokeless tobacco has a significant influence on the synthesis of secretory IgA, the numbers of DMFS were similar between smokeless tobacco users and controls. Topics: Adolescent; Adult; Amylases; Antibodies, Bacterial; Blood; Glucosyltransferases; Humans; Immunoglobulin J-Chains; Immunoglobulins; Lactoferrin; Male; Muramidase; Plants, Toxic; Saliva; Salivary Proteins and Peptides; Secretory Component; Streptococcus mutans; Thiocyanates; Tobacco, Smokeless; Virulence | 1991 |
Antimicrobial proteins in human unstimulated whole saliva in relation to each other, and to measures of health status, dental plaque accumulation and composition.
Saliva antimicrobial proteins may interact in a common system to influence the oral ecology. Clinical studies of antimicrobial protein action thus may require a multiple-protein approach. Multivariate statistical methods have been used to describe possible patterns of interaction for lysozyme, lactoferrin, salivary peroxidase and secretory IgA in stimulated parotid saliva. However, oral microbes are most likely to encounter antimicrobial proteins in mixed resting saliva. Relationships among levels of lysozyme, lactoferrin, salivary peroxidase, and secretory IgA therefore were investigated in whole saliva from 216 subjects, and an attempt made to relate interperson variation in those proteins to differences in health and status, and dental plaque accumulation and composition. All proteins were significantly (alpha = 0.05) correlated with each other (r = 0.38-0.52, p less than 0.001). There was only one axis of common variation among proteins, and that axis was significantly correlated (p less than 0.001) with total protein (r = 0.84) and flow rate (r = -0.56). That pattern deviated from the previous finding that proteins of acinar origin tended to vary independently from proteins of ductal origin in stimulated parotid saliva. The difference between parotid and whole saliva may reflect constitutive secretion of all proteins at low levels of stimulation. Common variation of unstimulated saliva proteins suggests that antimicrobial actions can be compared in subjects at population extremes. There were no significant associations between antimicrobial proteins in whole saliva and measures of health status or plaque accumulation. However, the proportions of Streptococcus sanguis were significantly correlated with lysozyme (r = -0.26), lactoferrin (r = -0.34), peroxidase (r = -0.30), total protein (r = -0.37), flow rate (r = 0.24) and principal-components scores (r = -0.33) in a subset of subjects (n = 85) where commercial biochemical tests were used to supplement species identification by colony morphology. Those findings may indicate that saliva antimicrobial proteins can affect the composition of dental plaque. Topics: Adolescent; Adult; Bacteria; Bacterial Physiological Phenomena; Dental Plaque; Dental Plaque Index; Female; Health Status; Humans; Immunoglobulin A, Secretory; Lactoferrin; Male; Muramidase; Oral Health; Peroxidases; Saliva; Salivary Proteins and Peptides; Secretory Rate; Streptococcus; Streptococcus mutans; Streptococcus sanguis; Thiocyanates | 1991 |
Effects of lysozyme-thiocyanate combinations on the viability and lactic acid production of Streptococcus mutans and Streptococcus rattus.
Effects of human lysozyme (HLZ) combined with thiocyanate (SCN-) ions on mutans streptococci, both in physiologic salivary concentrations, were studied. The bacteria were incubated for 75 min either in HLZ-supplemented sterilized human whole saliva (pH 5 and 7) or in neutral buffer in the presence or absence of HLZ (30 mg/l)-SCN- (1-5 mM) combinations. HLZ had no inhibitory effect on the viability of Streptococcus mutans, serotype c, either in saliva or in buffer, not even at pH 5, in the presence of salivary bicarbonate or in higher (up to 240 mg/l) concentrations of HLZ. In contrast, HLZ significantly decreased the viability of S. rattus in both media. HLZ also effectively blocked the lactic acid production of S. rattus but not that of S. mutans. Thiocyanate ions, which have been proposed to enhance the antimicrobial activity of lysozyme, did not affect the antibacterial activity of HLZ or HLZ-HCO3- combinations. It is concluded that the in vivo levels of SCN- ions, which constitute an integral part of the peroxidase antimicrobial system in saliva, may not be high enough to trigger the lysis of S. mutans by lysozyme in human saliva. The very low prevalence of S. rattus compared with S. mutans in human populations may be associated with their different susceptibility to lysozyme-mediated inhibition in saliva. Topics: Buffers; Colony Count, Microbial; Humans; Hydrogen-Ion Concentration; Lactates; Lactic Acid; Muramidase; Saliva; Streptococcus; Streptococcus mutans; Thiocyanates | 1991 |