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- 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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| 2. |
- Pahumunto, N., et al.
(författare)
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Evaluation of Potential Probiotic Properties of Lactobacillus and Bacillus Strains Derived from Various Sources for Their Potential Use in Swine Feeding
- 2023
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Ingår i: Probiotics and Antimicrobial Proteins. - : Springer Science and Business Media LLC. - 1867-1306 .- 1867-1314. ; 15:3, s. 479-490
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Tidskriftsartikel (refereegranskat)abstract
- Beneficial effects of probiotics are relevant to the various potential properties of individual strains, and they may also relate to the original sources of the probiotic strains. This study aimed to characterize the potential probiotic properties of the strains originating from various sources for probiotics use in swine feeding. A total of 9 potential probiotic strains, seven lactobacilli and 2 bacilli, were examined for antimicrobial production against swine pathogens, adhesion and anti-adhesion of potential probiotic strains to IPEC-J2 cells, aggregation ability, host defense peptide expression, and hemolytic assay. The results highlight that all strains derived from different sources could exhibit probiotic properties, although different abilities were observed. L. rhamnosus SD11 exhibited the highest inhibitory effect against all pathogens compared to other strains. Bacillus licheniformis KMP-9, B. subtilis KMP-N004, and L. fermentum SD7 gave the highest internalization and that related to high abilities of exclusion, competition, and displacement inhibition to pathogens. Such strains also gave a higher co-aggregation to all pathogens compared to other potential probiotic strains. L. rhamnosus GG, L. fermentum SD7, L. rhamnosus SD4, and B. subtilis KMP-N004 had significantly higher pBD-2 mRNA expression than other strains. None of potential probiotic strains showed hemolytic activity. In conclusion, the strains derived from either humans or animals possessed desirable probiotic properties including inhibition against porcine pathogens, adhesion capacity to porcine enterocytes, anti-adhesion pathogens to porcine enterocytes, and modulated innate immunity. Results indicate that these probiotic strains may be good candidates for use in swine feeding to reduce the risk of infection.
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| 3. |
- Pahumunto, N., et al.
(författare)
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Oral Lactobacillus strains reduce cytotoxicity and cytokine release from peripheral blood mononuclear cells exposed to Aggregatibacter actinomycetemcomitans subtypes in vitro
- 2020
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Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background This study evaluated the effect of oral lactobacilli on the cytotoxicity and cytokine release from peripheral blood mononuclear cells (PBMCs) when exposed toAggregatibacter actinomycetemcomitanssubtypes in vitro.The supernatants and cell wall extracts (CWEs) of eightA. actinomycetemcomitansstrains, representing different subtypes, and threeLactobacillusstrains were used. The PBMCs from six blood donors were exposed to supernatants and CWEs ofA. actinomycetemcomitansorLactobacillusstrains alone or combinations and untreated cells as control. The cytotoxicity was determined by trypan blue exclusion method and IL-1 beta secretion by ELISA. TNF-alpha, IL-6, and IL-8 secretions were measured using Bioplex Multiplex Immunoassay. Results Supernatants or CWEs from all bacterial strains showed cytotoxicity and IL-1 beta secretion and the subtypes ofA. actinomycetemcomitansshowed generally a significantly higher effect on PBMCs than that of theLactobacillusstrains. Two highly toxicA. actinomycetemcomitansstrains (JP2 and JP2-like) induced a higher response than all other strains. When combined,Lactobacillussignificantly reduced the toxicity and the IL-1 beta secretion induced byA. acinomycetemcomitans. The effect varied between the subtypes and the reduction was highest for the JP2 and JP2-like strains. TheLactobacillus paracaseistrain SD1 had a higher reducing effect than the otherLactobacillusstrains. This strain had a consistent reducing effect on all subtypes ofA. actinomycetemcomitanscytotoxicity, and release of IL-1 beta, IL-6, IL-8, and TNF-alpha from PBMCs of the blood donors. A strong and significant variation in cytokine release between the six blood donors was noticed. Conclusions Lactobacillusspp. andL. paracaseiSD1 in particular, showed a limited but statistically significant reducing interaction withA. actinomycetemcomitanstoxicity and release of cytokines in vitro.
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| 4. |
- Pahumunto, N., et al.
(författare)
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Pro-inflammatory cytokine responses in human gingival epithelial cells after stimulation with cell wall extract of Aggregatibacter actinomycetemcomitans subtypes
- 2017
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Ingår i: Anaerobe. - : Elsevier BV. - 1075-9964. ; 48, s. 103-109
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Tidskriftsartikel (refereegranskat)abstract
- Varying cytokine responses of human gingival epithelial cells (HGECs) by Aggregatibacter actinomycetemcomitans subtypes have been found. Most studies have used reference strains, whereas a few has evaluated the cytokine expression in response to clinical subtypes of this bacterial species. This study aimed to examine whether there was any difference in cytokine responses of HGECs stimulated with cell wall extract (CWE) from A. actinomycetemcomitans subtypes included clinical strains from Thai adult periodontitis, various serotypes and non-serotypeable strains, strains from deep or shallow pockets, and reference serotype strains. Totally 50 clinical strains and 7 reference strains of A. actinomycetemcomitans were analyzed for the expression of IL-1β, IL-6, IL-8, and TNF-α mRNAs in HGECs by real time-PCR, and the IL-8 concentrations in cell-free supernatant measured using ELISA. An in vitro effect of released IL-8 on neutrophil migration was examined using transwell chambers. Result showed that among four cytokines studied, IL-8 mRNA was highly up-regulated by both clinical and reference strains. Serotype f revealed the highest expression compared to other serotypes. The JP2-like leukotoxin promoter gene and non-serotypeable (NS1 and NS2) demonstrated lower IL-8 responses compared to serotypeable strains, and IL-8 responses upon stimulation with clinical strains from deep pockets were also significantly lower than those isolated from shallow pockets (P < 0.01). Our findings suggest that the clinical isolates of A. actinomycetemcomitans associating with deep pockets, JP2-like leukotoxin promoter gene, NS1, and NS2 may interfere neutrophil function via minimal and immunosuppressing IL-8 responses, which may enhance their survival and virulence. © 2017 Elsevier Ltd
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| 5. |
- 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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