Douglas Bratthall

Streptococcus mutans in saliva: intraindividual variations and relation to the number of colonized sites

Analysis of the salivary levels of Streptococcus mutans may contribute to the evaluation of the caries risk. It is therefore important to identify factors that might influence the outcome of such analyses. This investigation consisted of three parts. The first aim was to evaluate the short-term variation of S. mutans concentration in saliva. Furthermore, we estimated the effect of discontinued oral hygiene on salivary S. mutans. We also analyzed the relation between salivary levels of S. mutans and the number of colonized approximal and occlusal sites. Tongue samples were also included in the comparison. Systematic short-term variation could not be demonstrated. A 95% confidence interval for an observed S. mutans value was obtained by multiplying and dividing the observed value by a factor of 5 (for S. mutans samples less than 10(6) or 2.3 (S. mutans greater than 10(6). One week of discontinued oral hygiene did not significantly change the level of S. mutans in saliva. Saliva samples correlated significantly with tongue samples and with the number of colonized approximal sites. The results of these studies confirm the stability of the S. mutans colonization level.

The More Streptococcus mutans, the More Caries on Approximal Surfaces

The relationship between the presence of Streptococcus mutans and caries on approximal tooth surfaces was studied in a group of 28 children who were 13 years old at baseline. 700 surfaces in the pre-molar and molar region were studied. Sampling of S. mutans was performed with a toothpick method at the beginning of the study and after one and two years. From bite-wing radiographs, the approximal surfaces were recorded as caries-free, decayed, or restored. Progression of lesions during the two years was also studied. More new caries lesions and progression caries lesions were found on surfaces positive for S. mutans than on surfaces without, and the more S. mutans, the more lesions, 52% of the surfaces with positive S. mutans findings at all three sampling occasions became carious or had caries in a progressive form. Among the surfaces with no detectable S. mutans, the corresponding figure was 8%. 80 out of the 530 surfaces diagnosed as intact at the start of the study became carious over the two-year period. 69 of these were S. mutans-positive at the first and/or second sampling.

Mutans Streptococci, Oral Hygiene, and Caries in an Adult Swedish Population

The objective of the present study was to describe the distribution of salivary mutans streptococci in a randomly selected adult population and to relate the distribution to the prevalence of caries. The aim was also to study the association between caries and different levels of oral hygiene (OH). The results were based on the assessment of caries, dental plaque, and concentration of salivary mutans streptococci in 914 subjects who represented 95% of an age- and gender-stratified population sample of 967 individuals, randomly selected from the total adult population living in Alvsborg County, Sweden. The results showed that the distribution of mutans streptococci among dentate adults not wearing any kind of removable denture(s) was similar to that previously reported from studies on Swedish schoolchildren, while a comparably higher proportion of subjects with high levels of mutans streptococci was found among the dentate individuals wearing some kind of removable denture(s). Even higher proportions were found among edentulous individuals with complete denture(s). There was a correlation between mutans streptococci concentration in saliva and caries. The subjects with lower concentrations showed a significantly lower mean number of decayed surfaces, compared with the individuals with higher concentrations of mutans streptococci in their saliva. The median OH standard was lower in the older age groups, and there was a higher ratio of decayed surfaces per remaining tooth in those age groups, in comparison with the younger groups. However, for individuals without mutans streptococci, no relation between OH standard and caries could be found and, regardless of OH standard, higher numbers of decayed surfaces were found with an increasing concentration of mutans streptococci in saliva.

Effect of a Professional Tooth Cleaning Program on Interdentally Localized Streptococcus mutans

The effect of a professionally performed tooth cleaning program on Streptococcus mutans in interproximal sites was studied. 35 children participated. In study 1, the program was per

Streptococcus mutans serotypes: some aspects of their identification, distribution, antigenic shifts, and relationship to caries.

For an immunologic point of view, several facts are worth consideration. S mutans can be separated into at least seven serotypes. Five of the types are based on antigens that may be specific for S mutans. One type, e, is related to the Lancefield group E streptocci, and one type, f, may lack an antigen that shows serological specificity. Analyses of plaque samples from individuals with a high caries activity have, in most instances, shown the presence of c, d, and possibly the g types. This does not necessarily mean that they are per se more cariogenic than the other types, but if all the serotypes cannot be combatted simultaneously, the c, d, and g types are an obvious first choice. S mutans strains do have antigens other than those used for serological identification, and it is not known which antigens can evoke antibodies with the highest protective capacity in humans. The phenomenon of antigenic shifts may make it possible for the bacteria to elude antibodies. However, the number of possible changes may be restricted. If certain antigens are of importance for the cariogenicity of S mutans, a change in their structure might result in a less cariogenic flora.

Mutans Streptococci in a Thai Population: Relation to Caries and Changes in Prevalence after Application of Fissure Sealants

The aims of this study were to evaluate the level of mutans streptococci in two groups of Thai (Bangkok) children; to relate the findings to caries prevalence and to the caries increment over 2 years, and to study whether different sealant and fluoride programmes affected levels of mutans streptococci over a 2-year period. The baseline survey comprised 1,114 children aged 12 years. For the sealant project, a minimum of three caries-free permanent molars was required; 752 children aged 12-13 and 512 children aged 7-8 years were distributed into five groups: control group, Delton fissure sealant group, glass ionomer fissure sealant applied by dentist (GIC-dentist group) or by school teachers given a 3-day course (GIC-teacher group), and an HF group (0.5% HF solution applied 3 times). The WHO standard criteria were used to record caries. Prevalence of mutans streptococci was estimated using the Strip mutans test. Mean DMFT (n = 1,114) of 12-years-olds was 2.96; 17% had Strip mutans class 0 (low level), 32% class 1, 33% class 2 and 18% class 3 (the corresponding mean DFT +/- SD for each mutans streptococci class was 1.84 +/- 2.33, 2.23 +/- 2.14, 3.18 +/- 2.75, and 3.59 +/- 3.01 respectively). For the 7- to 8-year-olds (n = 512), mean df teeth at baseline was 5.36 (d = 5.19; f = 0.17); 5% had Strip mutans class 0, 17% class 1, 33% class 2 and 45% class 3 (the corresponding mean df teeth was 3.19 +/- 2.5, 4.13 +/- 2.84, 4.89 +/- 2.94 and 6.39 +/- 3.16 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Association between bacterial agglutinins and immunoglobulin A in human saliva

Two distinct peaks were obtained when human parotid saliva was separated on a Sepharose 2B column. The bacterial agglutinating activity was concentrated to the void volume fractions whereas the IgA was found in the beginning of the second, large peak. Unfractionated saliva as well as the pooled agglutinin fractions, or a mixture of agglutinin and IgA, all induced the aggregation of KPSK2, a Streptococcus mutans serotype c strain. By adding anti-human-IgA antiserum to the whole saliva or to the mixture of agglutinin and IgA, the aggregation reaction could be eliminated. In order to achieve this effect the agglutinin and IgA had to be mixed prior to the addition of anti-IgA. Addition of anti-IgA antiserum to the agglutinin fraction only did not impair the aggregation of bacteria. The homologous reactions with anti-IgG antiserum did not give any inhibition effect. However, when human IgG was added to the saliva, or to the agglutinin, before the addition of anti-IgG, the aggregation of KPSK2 was again impaired. The data in this paper indicate that the agglutinins and the IgA antibodies in saliva may be normally associated with each other.

Histologic and sialochemical findings indicating sicca syndrome in patients with systemic lupus erythematosus.

Twenty unselected patients with systemic lupus erythematosus (SLE) were investigated with respect to symptoms and signs of salivary gland involvement. Eight of them complained of xerostomia. Whole salivary flow was measured, parotid saliva was analyzed chemically, and palatal biopsy was performed to assess the degree of inflammatory infiltration in minor salivary glands. All but one of the patients showed signs of involvement on at least one of the tests and, as a group, the patients with SLE had significantly reduced values for salivary flow and increased concentrations of sodium, protein, and carbohydrates as compared to matched healthy controls.

Secretory and serum antibodies against Streptococcus lactis, Streptococcus thermophilus, and Lactobacillus bulgaricus in relation to ingestion of fermented milk products.

Serum, saliva, and urine were analyzed for the presence of IgA, IgG, and IgM antibodies reactive with the yoghurt bacteria Streptococcus thermophilus and Lactobacillus bulgaricus. A comparison was made between four subjects who frequently ate yoghurt and four subjects who never ate yoghurt. Salivary IgA and serum IgG activity against the milk-fermenting bacterium S. lactis was studied in five other subjects before, during, and after a period of ingestion of a fermented milk product, filmjölk. All analyses were carried out by an enzyme-linked immunosorbent assay method. Antibody activity against the yoghurt bacteria was found in saliva, serum, and urine. No difference in antibody activity between yoghurt eaters and non-yoghurt eaters was measured for salivary IgA, but for serum IgG a lower activity against S. thermophilus was present among the yoghurt eaters. Antibody activity against S. lactis was present already before the ingestion of filmjölk began, and the activity was not altered during the period of ingestion. It is concluded that in adult subjects, the ingestion of milk-fermenting bacteria does not result in a significant change in the antibody activity against these bacteria.

Detection of Antigens in Enzymic Lysates of Cell Wall from Streptococcus mutans Strains

Lysis of cell wall preparations from strains representing serotypes a - g of Streptococcus mutans has provided a convenient and efficient means of obtaining the typing antigens in a soluble undegraded form, and has demonstrated that, in each case, the antigen is a cell wall component in the strict sense of a component joined covalently to peptidoglycan. This influences the choice of extraction procedures.