| 1. |
- Piwat, S, et al.
(författare)
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Lactobacillus species and genotypes associated with dental caries in Thai preschool children.
- 2010
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Ingår i: Molecular oral microbiology. - : Wiley. - 2041-1014 .- 2041-1006. ; 25:2, s. 157-64
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacilli have been associated with the presence and progression of dental caries. Nevertheless, the relation between certain species or genotypes of Lactobacillus and caries is unclear and there are no data available for the Thai population. This study aimed to examine the distribution of species and genotypes of oral Lactobacillus among children with rather high caries prevalence, and to investigate whether certain species or genotypes were more related to caries activity than others. One hundred and sixty-five children were examined for caries status. Saliva samples were collected and the numbers of lactobacilli were counted. A total of 357 Lactobacillus isolates from 59 children were identified to species level by 16S ribosomal RNA genes polymerase chain reaction (PCR) -restriction fragment length polymorphism and 16S ribosomal RNA gene sequencing. Furthermore, 304 isolates from 56 children were genotyped using arbitrarily primed PCR. Significant correlation was found between levels of lactobacilli and dental caries (P < 0.001). Among the 10 identified species of Lactobacillus, L. salivarius was more prevalent in children with moderate to high caries prevalence compared with children with low caries prevalence, while L. fermentum was the most predominant species in all study groups. Moreover, a genetic heterogeneity of Lactobacillus species was found among the children and those with high caries prevalence tended to be colonized with more than one clonal type. In summary, L. salivarius may be a putative caries pathogen among preschool Thai children.
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| 2. |
- Pahumunto, N., et al.
(författare)
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Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes in Thai adults with chronic periodontitis
- 2015
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Ingår i: Archives of Oral Biology. - : Elsevier BV. - 0003-9969 .- 1879-1506. ; 60:12, s. 1789-1796
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Tidskriftsartikel (refereegranskat)abstract
- © 2015 Elsevier Ltd. All rights reserved. Objective To investigate the distribution of Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes among isolates from Thai chronic periodontitis patients. Design Forty-four adult Thai periodontitis patients were assessed by a full mouth recording for CAL, PPD, and BOP. Seventy-nine strains of A. actinomycetemcomitans were isolated from deep pockets on selective TSBV agar and 17 strains were isolated from shallow pockets. The strains were serotyped using PCR and subtyped using DGGE. Results The prevalence of A. actinomycetemcomitans was 84.1%. Non-serotypeable A. actinomycetemcomitans strains occurred equally frequent as serotypeable (54.5%); serotype a 18.2%, serotype c 15.9%, serotype e 9.1%, and serotype f 11.4%. Serotype b and d were not detected. A JP2 like strain but serotyped as c was isolated from two patients, and another two strains showed an 886 bp insertion on the ltx promoter of their A. actinomycetemcomitans isolates. DGGE typing disclosed 16 different subtypes among the non-serotypeable strains. Two of them (NS1 and NS2) were more common (12.7 and 10.1%) among the strains than the other 14 subtypes (<5.1%). Most patients showed only one subtype (32.4%) but 29.7% had 2 and 3 different subtypes while 8.1% revealed 4 subtypes in one and the same deep pocket. Conclusion This study showed a greater subtype diversity of A. actinomycetemcomitans predominated by non-serotypeable strains than previously reported in an adult Thai population. It was also revealed for the first time that isolates with a 530 bp deletion or 886 bp insertion of the ltx promoter were serotyped as serotype c.
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| 3. |
- Piwat, S., et al.
(författare)
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Periodontal diseases in Thai schoolchildren. Clinical and microbiological observations
- 2023
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Ingår i: Odontology. - 1618-1247.
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of periodontitis among Thai schoolchildren is unknown. In a cross-sectional study, the prevalence and severity of periodontal diseases, in a group of Thai schoolchildren, along with the presence and numbers of bacterial species commonly associated with periodontitis were investigated. A consent form was sent out to 192 schoolchildren in one school (Chanachanupathom School) in Chana, Southern Thailand (in the age range of 12-18 years) and 119 attended for a clinical and microbiological examination. Clinical recordings included number of teeth present, DMFT, plaque index, bleeding index, clinical attachment loss (CAL), and probing pocket depth (PPD). Pooled plaque samples were analyzed with culture and qPCR against bacteria associated with periodontitis. The children had low caries experience (DMFT = 3.2 +/- 2.3), poor oral hygiene, high bleeding scores, and 67 (56.3%) had at least one interproximal site with CAL >= 1 mm. Thirty-seven (31.1%) of the children were diagnosed with periodontitis stage I, and sixteen (13.4%) were classified as periodontitis Stage II. Aggregatibacter actinomycetemcomitans was sparsely found in all but the healthy clinical groups (gingivitis, periodontitis Stage I and II), while the groups showed a high prevalence of Fusobacterium spp., Prevotella intermedia/nigrescens, and Campylobacter species as well as of the periodontitis-associated species Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. Thai schoolchildren have poor oral hygiene with abundant amounts of plaque and high presence of bleeding. Early onset periodontitis is common but mostly in its mild form and is not associated with the presence of A. actinomycetemcomitans.
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| 4. |
- Piwat, S, et al.
(författare)
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Site-specific dental plaque pH in 13-year-old Thai schoolchildren.
- 2015
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Ingår i: Clinical oral investigations. - : Springer Science and Business Media LLC. - 1436-3771 .- 1432-6981. ; 19:9, s. 2179-2186
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper was to study pH conditions between dental sites, taking account the presence of caries, calculus, and microbial composition and alkali production.
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