We developed a Colorimetric microtiter plate‐based assay for the detection and quantification of polymerase chain reaction‐amplified DNA fragment specific for Actinobacillus actinomycetemcomitans . We amplified the 396‐bp leukotoxin‐specific DNA fragment by using two oligonucleotide primers, one carrying a biotin group at the 5’end and another one with a digoxigenin at the 5’end. Following amplification, the biotinylated polymerase chain reaction products were applied to a microtiter well precoated with avidin. The Colorimetric detection and quantification were achieved by an enzyme‐linked immunosorbent assay using alkaline phosphatase‐conjugated anti‐digoxigenin antibody. The detection limit of the Colorimetric assay was found to be as little as 500 fg of purified A. actinomycetemcomitans DNA and as few as 50 A. actinomycetemcomitans cells. The absorbance values in the Colorimetric assays were log‐linear between 500 fg and 1 ng of purified DNA and between 50 and 10 5 cells of A. actinomycetemcomitans . Therefore, this Colorimetric assay was able to estimate the amount of A. actinomycetemcomitans in subgingival plaque samples. We concluded that the colorimetric assay of the PCR product is a very useful method not only to detect the presence of A. actinomycetemcomitans but also to quantify the amount of A. actinomycetemcomitans in large numbers of subgingival plaque samples.
Toothbrushes after use are contaminated by many microorganisms including bacteria, fungi and viruses. We are thinking of making an anti-bacterial toothbrush by including ceramics in the bristle. But if the ceramic-containing bristles are too hard for the tooth and gingiva, it cannot be used as a toothbrush. So, before examining the antibacterial properties, we evaluated the feeling by asking students of dental hygiene. In our preliminary experiment, we determined the most appropriate width and length of ceramic-containing bristles. The students used this toothbrush and answered the questions. Almost all the students were satisfied with the new toothbrush with ceramic-containing bristles. Moreover, the new toothbrush was found to be comparable with the world-wide sold toothbrush. We obtained data that the ceramic-containing bristles were acceptable. Further study to investigate the anti-bacterial properties and effective cleanliness are in progress.
The systemic injection of an aqueous suspension of cell wall or its peptidoglycan (PG)-rich sonicate derived from group A streptococcus and Lactobacillus casei induced acute joint lesions in BALB/c, DBA/1J, (BALB/c X DBA/1J)F1, and C3H/He mouse strains, but not in C57BL/6, DBA/2, and AKR strains. Cell walls and their enzymatically degraded PG fragments from other bacteria as well as the synthetic disaccharide dipeptide and Lactobacillus plantarum cell wall-derived disaccharide tripeptide produced similar acute inflammation in susceptible BALB/c mice. Acute swelling and erythema of the ankles and wrists were observed as early as 3 h, reached maximum severity by day 2, and generally subsided by days 4 to 6 after injection. Histological studies showed synovial proliferation, marked infiltration of many mononuclear cells and a few polymorphonuclear leukocytes in the soft tissues, and extensive deposition of fibrinous exudate in the joint space. Antibody response was detectable against the PG fraction. However, anti-PG antibody does not seem to be responsible for the pathogenesis of this disease. On the other hand, experiments on decomplementation by cobra venom factor suggest that complement components are involved in the early phase of this arthritic model.
Objective: A randomized, double-blind, placebo-controlled crossover comparative study was conducted in a healthy older population to assess the usefulness of Lactobacillus salivarius WB21 (WB21) ingestion for oral self-care. Methods: The study population included 33 healthy older individuals who were randomly divided into two groups (A and B). Group A consumed WB21 tablets during the first two months and placebo tablets during the following two months. Group B consumed placebo tablets during the first two months and WB21 tablets during the following two months. Before and after ingestion, oral examination, mouth odor test, and saliva collection were performed a total of four times. In addition, health conditions were obtained from a questionnaire survey at the study’s midpoint. Results: Two people in group A and one person in group B dropped out of the study. Thus, 15 people in group A and 15 people in group B were included in the analysis. Over two months of WB21 ingestion, salivary secretory IgA increased significantly (p = 0.047) and tongue coating score decreased significantly (p = 0.013). The plaque index, bleeding on probing, and mouth odor levels (H2S and CH3SH concentrations) did not change. During the 6-month study period, no caries, deterioration of periodontitis, or changes in oral health or systemic subjective symptoms were observed. Conclusion: Continuous ingestion of WB21-containing tablets may promote self-care of the teeth and mouths of healthy older adults. Trial registration: R000028335 (UMIN-CTR).
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