Biomedical subjects

Nobuko Maeda

Publications and source records attributed to Nobuko Maeda.

7 recordsLinked to original sources

PubMed2007

Distribution of salivary Lactobacillus and Bifidobacterium species in periodontal health and disease.

We surveyed the distribution of salivary Lactobacillus and Bifidobacterium species in periodontitis patients and healthy subjects. Approximately 700 lactobacilli and 300 bifidobacterial isolates were obtained from 16 young, orally healthy subjects (mean age +/- standard deviation: 21.0+/-2.0 y), 16 periodontitis patients (51.6+/-13.8 y), and 14 well-maintained former periodontitis patients (60.2+/-9.6 y). Among eleven Lactobacillus species detected in saliva, L. salivarius, L. gasseri, and L. fermentum were prevalent, but no species was specifically associated with periodontal health. In contrast, of four Bifidobacterium species, B. adolescentis was specifically (P<0.05) prevalent in young healthy subjects compared with the other two groups. Furthermore, the bifidobacterial count of the well-maintained subjects was the highest (P<0.05) among the groups. These results suggest that bifidobacterial count and species might be associated with periodontal health status and/or age.

Adult↗

PubMed2006

The carriage of Candida species on the dorsal surface of the tongue: the correlation with the dental, periodontal and prosthetic status in elderly subjects.

OBJECTIVES: To screen the carriage status of Candida species, especially Candida albicans and its genotype in an epidemiological survey and to investigate its correlation with the dental, periodontal and prosthetic status of healthy elderly subjects. MATERIALS AND METHODS: Microbiological samples were collected from the dorsum of the tongue of 366 subjects, aged 75, and cultured on CHROMagar medium. The carriage status of Candida spp. and the distribution of C. albicans genotypes by a polymerase chain reaction (PCR) method were analysed and compared with the dental, periodontal and prosthetic status of the subjects. RESULTS: A high carriage rate (68.6%) of Candida spp. and the predominant species of C. albicans (72.1%) were found in this study. The prevalence, density and multi-species of Candida spp. were significantly related to the presence of a dental prosthesis. In C. albicans, genotype A predominated (56.4%) and genotype D showed a higher prevalence (12.5%) than previous reports. When comparing Candida spp. carriage with the oral status, significant positive correlations were found with the presence of any dental prosthesis, missing teeth, the number of retained roots and the percentage of sites showing bleeding on probing (BOP), while significant negative correlations were found with the number of teeth present, sound and filled teeth. CONCLUSIONS: Candida carriage on the dorsum of the tongue in healthy elderly is significantly associated with the dental, periodontal and prosthetic status, especially the presence of a dental prosthesis. As the complexity of the prosthesis being worn increased, the relative risk of Candida carriage and the numbers and multi-species of Candida increased accordingly.

Aged↗

PubMed2005

Relationship between oral Candida species and risk factors with reference to drugs with xerostomic side effects among institutionalised elderly in Aichi Pref., Japan.

OBJECTIVE: To clarify the relationship between Candida carriage and drugs which have reported xerostomic side effects in the elderly. DESIGN: Cross-sectional study. Setting Two long-term care facilities in Aichi Pref., Japan. PARTICIPANTS: Eight men and 63 women with a mean age of 86 years (range 62 to 95 years) with at least some of their natural teeth. METHOD: Oral examination by dentists, microbiological test by microbiologists, questionnaire interviews, and data obtained from medical files. The Candida species (CFU) was adopted as an objective variable with risk indicators being age, number of teeth, saliva flow rate, denture wearing, xerostomic drugs, activities of daily living (ADL), frequency of brushing and type of meals. RESULTS: Bivariate analysis confirmed that participants with a higher number of Candida species (CFU) fell into the following categories: denture wearing (p < 0.05), older age (p < 0.05), xerostomic drugs (p < 0.10), more teeth, poor ADL, soft/liquid meals, and brushing once a day. This was in contrast to the categories of no denture wearing, younger age, no xerostomic drugs, fewer teeth, good ADL, normal meals, and brushing two or more times a day, in that order of significant probability on an ascending scale. A multiple logistics regression model confirmed that the variables of older age (80 years and over) and more teeth (six or more) had statistically significant (p < 0.05) effects on the number of Candida species present (CFU). Xerostomic drugs and the other variables had no significant effect. CONCLUSION: Older age and more teeth had a significant effect on the number of oral Candida species in the elderly. The results of this study did not support a role of those drugs as a risk indicator for oral Candida carriage. Larger trials are needed to assess the effect of drugs on the presence of oral Candida.

Age Factors↗

PubMed2005

Differentiation of Candida albicans and Candida dubliniensis using a single-enzyme PCR-RFLP method.

Candida dubliniensis is a novel Candida spp. that is similar to Candida albicans with respect to several phenotypic characteristics. However, they differ from each other with respect to epidemiology, pathogenesis, and the rapid development of resistance to fluconazole. In the present study, we used a single-enzyme PCR-restriction fragment length polymorphism (RFLP) technique to differentiate C. dubliniensis from C. albicans. The amplified ITS region of C. dubliniensis was digested once using the enzyme B1nI, whereas that of C. albicans remained intact. All standard strains tested were identified successfully by this method. None of 140 clinical isolates identified morphologically as C. albicans were recognized as C. dubliniensis based on their PCR-RFLP pattern. Our PCR-RFLP method easily differentiated C. dubliniensis from C. albicans, and this result was also demonstrated with standard strains.

Adult↗

PubMed2004

Identification of the anginosus group within the genus Streptococcus using polymerase chain reaction.

The aim of this study was to establish an identification method for the anginosus group within the genus Streptococcus by polymerase chain reaction (PCR). Using a primer pair based on the group-specific sequences of penicillin-binding protein 2B (pbp2b) gene, a 275-bp fragment was amplified from each species in the group but no size-matched products were obtained in other streptococci. Further identification in the species or subspecies level was possible by a multiplex PCR with primers for the 16S ribosomal RNA gene of Streptococcus anginosus, the hyaluronate lyase genes both of Streptococcus intermedius and Streptococcus constellatus subsp. constellatus, and the intermedilysin (ily) gene of S. intermedius. In the case ofStreptococcus constellatus subsp. pharyngis, the amplified fragment from the S. intermedius-type hyaluronate lyase gene was obtained, while that from the ily gene was not. These results also indicate that two different hyaluronate lyase genes are distributed among the anginosus group.

Aminoacyltransferases↗

PubMed2004

Detection of penicillin-binding protein 2b gene alteration in Streptococcus mitis by polymerase chain reaction.

Three isolates of beta-lactam-resistant streptococci from the saliva of healthy adults were identified as Streptococcus mitis. Minimum inhibitory concentrations (MICs) were 2 to 4 micro g/ml for ampicillin (ABPC) and 64 to more than 128 micro g/ml for cefaclor (CCL). To determine the position of base alterations of the penicillin-binding protein 2b ( pbp2b) gene, upstream primers containing possible mutation points were designed, and used for polymerase chain reaction (PCR), together with a downstream primer. Alterations adjacent to the conserved motifs of the pbp2b gene were apparent. DNA sequencing data indicated replacements in deduced amino acid sequences in all resistant isolates: from threonine to alanine just after the serine-serine-asparagine (SSN) motif, and from alanine to glycine two residues downstream of the lysine-threonine-glycine (KTG) motif. These changes were the same as those in penicillin-resistant Streptococcus pneumoniae (PRSP), suggesting importance for the enzymatic activity of the protein. Thus, Beta-lactam susceptibility of S. mitis may be partially predicted by PCR using our primer set for pbp2b.

Aminoacyltransferases↗

PubMed2003

[Phenotypic variation in Actinobacillus actinomycetemcomitans].

OBJECTIVE: To investigate the colony variation in Actinobacillus actinomycetemcomitans (Aa) from rough to smooth and recognize its different morphology during laboratory translations. METHODS: Primary strains isolated from subgingival plaque of two juvenile periodontitis patients were repeatedly subcultured on agar plates and broth; for broth culture, every generation was translated in broth and on solid medium separately to observe the corresponding morphologies of Aa grow in broth. RESULTS: Three smooth strains of Aa from the broth culture were obtained. The process was about 7-8 generations: colonies changed from a small and adherence phenotype to a bigger and sediment ones and finally the culture supernatant became turbid; the corresponding morphologies grow on agar exhibiting an adherent, small rough colony phenotype which had a star-shaped internal structure converted gradually to a kind of bigger, opaque, nonadherent, smooth phenotype, then the colony extended out from the margin of the colony and finally converted to a flat, almost parent morphology and the same time the star-like inner structure converted to a simpler and smaller type and finally disappeared. We could not get completely smooth variants of Aa from agar. CONCLUSIONS: The variation in colony morphology of Aa from rough to smooth is a process, in which the colony was gradually wetter and bigger and at the same time gradually lost the inner structure. During this process three colony morphologies at least can be seen, including rough, opaque smooth and almost translucent smooth.

Aggregatibacter actinomycetemcomitans↗