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Biomedical subjects

D Bratthall

Publications and source records attributed to D Bratthall.

At least 91 records · Page 5Linked to original sources
PubMed1979

Practical method to facilitate estimation of Streptococcus mutans levels in saliva.

A method was developed to facilitate the estimation of Streptococcus mutans levels in saliva. Saliva-contaminated wodden spatulas were pressed directly against an elevated agar plate containing a selective medium. The results were compared with the number of S. mutans per 1 ml of paraffin-stimulated saliva. It was shown that the spatula method gave a good estimation of the level of S. mutans infection. The incubation was also made in expired air instead of 95% N2-5% CO2. The outgrowth was in good agreement with that after conventional incubation. The method is useful in epidemiological studies or in selecting persons at a high caries risk, and when ordinary saliva sampling cannot be done, for example in small children. Compared with conventional saliva sampling, this method requires less time and material at sampling as well as at the laboratory.

Adult↗
PubMed1979

Examination of parotid saliva for antibodies reacting with Streptococcus mutans, lipoteichoic acid and peptidoglycan by the enzyme-linked immunosorbent assay.

Human parotid saliva was investigated for the presence of IgA antibodies reacting with Streptococcus mutans, lipotechoic acid (LTA) and peptidoglycan. By using an enzyme-linked immunosorbent assay, ELISA, it was shown that the salivas of 12 subjects contained antibodies reacting with S. mutans serotype c and d and with LTA. Six salivas were tested against peptidoglycan but these tests indicated only low levels of antibodies. Absorption of saliva with whole cells of S. mutans inhibited the homologous reaction by up to 87% and the reaction with LTA by up to 52%. Also prior treatment of saliva with LTA caused a decrease in the salivary IgA reaction with LTA and with whole cells of S. mutans. Addition of peptidoglycan to saliva did not markedly affect the salivary IgA reaction with S. mutans. The data show that LTA may be responsible for part of the salivary IgA reaction with whole cells of S. mutans. The significance of LTA in this reaction may vary between different subjects and for different serotypes of S. mutans.

Adolescent↗
PubMed1978

Daucus carrota (carrot)--a selective bacteriosorbent.

1) An extract of D. carrota induces agglutination of most serotypes of S. mutans but not of S. salivarius or S. mitis. 2) If added to a suspension of mixed bacteria, a piece of D. carrota may selectively sorb S. mutans while S. salivarius and S. mitis only are affected to a minor degree. 3) A saliva coat on the bacteria may reduce the uptake of S. mutans to D. carota but does not totally prevent it.

Humans↗
PubMed1978

Antibodies reacting with Streptococcus mutans in secretions from minor salivary glands in humans.

1) Antibodies reacting with S. mutans in secretions from minor salivary glands in humans were determined by a modified Enzyme Linked Immunosorbent Assay. 2) IgA antibodies reacting with S. mutans serotype c were found in all samples examined. 3) The antibody level in the secretions of the minor salivary glands varied considerably between different subjects and was considerably higher than that of parotid saliva. 4) A variation in antibody concentration over time was observed in some individuals. 5) Topical application of a streptococcal vaccine consisting of formalin killed cells increased the level of antibodies in the secretions of one person. In two persons no effect was observed.

Antibodies, Bacterial↗
PubMed1978

Intrafamilial levels of Streptococcus mutans and some aspects of the bacterial transmission.

The number of S. mutans (S.m.) in saliva of parents and their children was studied. Thirty-six children, 4 1/2-5 years old, and their parents participated. A quantitative correlation was found between the number of S.m. in the mothers and their children. The degree of infection also seemed to reflect the caries experience of the child. When adults with different levels of S.m. in saliva contaminated metal spoons with saliva, a correlation between the salivary count of S.m. and the number of microorganisms transferred to the spoon was found. The survival of S.m. on saliva-contaminated test-plates was tested. After 7 h the number of viable S.m. had decreased considerably but a few cells could be found after 24-48 h. To study the presence of S.m. on objects in the city often touched by hands, MSB-containing agar dishes were pressed against several objects such as doorhandles. Only four out of 24 objects were found to be contaminated by S.m.

Adult↗
PubMed1978

Salivary agglutinin and secretory IgA reactions with oral streptococci.

S. mutans, S. salivarius, S. mitis and S. sanguis strains were isolated from three subjects of blood groups A, B and O. Parotid saliva samples obtained from the same subjects induced aggregation of some of the bacteria, the S. sanguis and the S. mutans strains in particular. While parotid saliva from the three subjects gave almost identical reactions, slight interindividual differences were observed for a few strains with the submandibular sublingual salivas. In parotid saliva, secretory antibodies reacting with all strains were present. The antibody levels differed between the three subjects but no specific pattern was observed when homologous strains were compared with heterologous strains.

Adult↗
PubMed1976

Serological and genetic examination of some nontypical Streptococcus mutans strains.

Thirty-four strains of Streptococcus mutans whose antigenic or genetic positions were unclear or unknown with respect to the serological scheme of Bratthall (1970) and Perch et al. (1974), or the genetic (deoxyribonucleic acid base sequence homology) scheme of Coykendall were analyzed to clarify their relationship to previously well-characterized strains. Strain OMZ175 of the "new" serotype f was genetically homologous with strains of S. mutans subsp. mutans. Strains of the "new" serotype g were homologous with serotype d strains (S. mutans subsp. sobrinus). Strains isolated from wild rats constituted a new genetic group but carried the c antigen. Thus, strains within a "genospecies" (subspecies) of S. mutans may not always carry a unique or characteristic antigen. We suggest that the existence of multiple serotypes within subspecies represents antigenic variation and adaptations to hosts.

Animals↗
PubMed1976

Growth of Streptococcus mutans on various selective media.

The ability of Streptococcus mutans to grow on mitis-salivarius (MS) agar, MC agar, mitis-sucrose-bacitracin (MSB), BCY agar, and MM10 sucrose agar was studied. Batch cultures of S. mutans serotype a demonstrated no growth on MSB agar. Certain serotype d and g strains did not grow on MC agar. The yield for most strains of other serotypes on these selective media was lower compared with that on MS agar. The number of total colony-forming units on BCY and MM10 sucrose agar was similar to the blood agar results. Similar data were obtained when fermenter-grown strains, harvested in the middle or the end of the logarithmic growth phase, were used for inoculation of the various media. Enumeration of S. mutans from plaque samples plated on MC and MSB agar yielded about 75% of the counts obtained on MS or the nonselective medium. When the proportions of S. mutans were expressed as a percentage of the total cultivable flora, the selective media (MC and MSB agar) showed approximately 10% lower values than the MS, BCY, and MM10 sucrose agar.

Agar↗
PubMed1976

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.

Adolescent↗
PubMed1975

Changing agglutination activities of salivary immunoglobulin A preparations against oral streptococci.

Immunoglobulin A (IgA) was prepared from samples of parotid saliva collected from two individuals over a 150-day period. Standardized solutions of the IgA were tested for agglutinating antibody activity against strains of streptococcus salivarius, S. sanguis, S. mitis, and S. mutans that had been isolated from a homologous individual on day 30 and preserved in the lyophilized state. The agglutinating activity of the standardized IgA preparations against these strains was found to change over time, whereas the agglutination patterns of IgA prepared from saliva samples collected 3 days apart were generally similar. Differences in agglutination titers were also observed between IgA samples prepared from saliva collected on day 0 and day 150. The data indicate that the oral cavity may harbor streptococci of different antigenic composition representing the same species at a given time and that parotid IgA agglutinating antibody against these serotypes changes over time.

Adult↗
PubMed1975

Antigenic variation of Streptococcus mutans colonizing gnotobiotic rats.

Strains of Streptococcus mutans representative of serotypes b and d exhibited antigenic variation in both the oral cavity and in the intestinal canal of gnotobiotic rats. Laboratory-maintained cultures did not vary. The antigenic alterations observed were: (i) loss of detectable levels of both weakly reacting "strain" antigens and the type antigen; (ii) decreased production of the type antigen; (ii) production of altered type antigen; and (iv) production of an antigen not possessed by the parent strain. Immunization of animals before monoinfection with S. mutans strain Bob-1 (serotype d) appeared to increase the rate of emergence of antigenically altered mutants in the intestinal canal, and more diversely altered isolates were obtained. Antigenic variation may account in part for the variation noted by several investigators in attempting to immunize animals against S. mutans-induced dental caries.

Animals↗