| 1. |
- Anderson, Maria, et al.
(författare)
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Oral microflora in preschool children attending a fluoride varnish program: a cross-sectional study.
- 2016
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Ingår i: BMC oral health. - : Springer Science and Business Media LLC. - 1472-6831. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- To compare the oral microflora in preschool children attending a fluoride varnish program with a reference group receiving a standard oral health program without fluoride varnish applications. A second aim was to relate the microbial composition to the caries prevalence.Five hundred seven 3-year-old children were enrolled from a cohort of 3403 preschool children taking part in a community based oral health project. Two hundred sixty-three of them had attended caries-preventive program with semi-annual applications of a fluoride varnish since the age of 1year (test group) while 237 had received standard preventive care (reference group). Oral samples were collected with a sterile swab and analysed with checkerboard DNA-DNA hybridization using 12 pre-determined bacterial probes. Caries and background data were collected from clinical examinations and questionnaires.Gram-positive streptococci (S. intermedius, S. salivarius, S. oralis) were most frequently detected and displayed the highest counts in both groups. There were no significant differences between the groups concerning prevalence of any of the selected bacterial strains except for S. oralis that occurred less frequently in the reference group. In children with caries, V. parvula were significantly more common (p<0.05) while strains of Lactobacillus, Bifidobacterium and Neisseria were more prevalent among the caries-free children (p<0.05).A 2-year community program with semi-annual fluoride varnish applications did not seem to significantly influence the oral microflora in preschool children.www.controlled-trials.com (ISRCTN35086887) 20131216 'retrospectively registered'.
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| 2. |
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| 3. |
- Arirachakaran, P., et al.
(författare)
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Non-oral, aerobic, Gram-negative bacilli in the oral cavity of Thai HIV-positive patients on Highly-active anti-retrovirus therapy medication
- 2019
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Ingår i: Journal of Investigative and Clinical Dentistry. - : Wiley. - 2041-1618 .- 2041-1626. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we identified and evaluated the antibiotic susceptibility of 96 independent, aerobic, Gram-negative bacillus isolates from 255 Thai HIV-positive adults who were on Highly-active anti-retrovirus therapy (HAART) medication. Another 46 isolates from HIV non-HAART individuals, vertically transmitted HIV-positive individuals, and non-HIV controls were included for comparison. A total of 103 strains were tested for antibiotic susceptibility using disc diffusion for screening and E-test for minimal inhibitory concentration determination, with special attention on extended-spectrum beta-lactamase (ESBL) isolates. Pseudomonas aeruginosa, Pseudomonas luteola, Burkholderia cepacia, Aeromonas hydrophila, Klebsiella, and Enterobacter species were the most common bacteria. All strains were resistant against penicillin, amoxicillin, clindamycin, and metronidazole. No ESBL isolates were found.
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| 4. |
- Basic, Amina, et al.
(författare)
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Estimation of bacterial hydrogen sulfide production in vitro.
- 2015
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Ingår i: Journal of oral microbiology. - : Informa UK Limited. - 2000-2297. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways.
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| 5. |
- Basic, Amina, et al.
(författare)
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H2S mediates increased interleukin (IL)-1β and IL-18 production in leukocytes from patients with periodontitis
- 2019
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Ingår i: Journal of Oral Microbiology. - : Informa UK Limited. - 2000-2297. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- - Background: The mechanisms involved in the interplay between the bacteria and the host cells in periodontitis are not fully understood. Aim: To investigate the effect of the bacterial metabolite H2S on the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 from periodontitis patients and healthy controls, and to evaluate the composition of the subgingival microbiota with its capacity to produce H2S. Methods: Subgingival bacterial samples from patients with periodontitis (N=32) and healthy controls (N=32) were investigated for H2S production and bacterial composition. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence/absence of 1mM H2S for 24h and cytokine concentrations were measured. Results: Subgingival plaque from periodontitis patients had more H2S producing bacteria and produced more H2S, than healthy controls. PBMCs exposed to H2S secreted significantly more IL-1ß and IL-18 (p<0.0001) than untreated control PBMCs from both groups. PBMCs from the periodontitis patients secreted higher levels of the cytokines, both spontaneously (IL-1ß p=0.0001; IL-18 p=0.09) and after exposure to H2S (IL-1ß p=0.03; IL-18 p=0.04), which is a new finding not previously reported. Conclusions: H2S, from the subgingival microbiota, can contribute to a host inflammatory response through secretion of the pro-inflammatory cytokines IL-1β and IL-18. Since this response differs between individuals, it may also reflect the susceptibility of the host to develop periodontitis. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 6. |
- Basic, Amina, et al.
(författare)
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Hydrogen sulfide exposure induces NLRP3 inflammasomedependent IL-1 beta and IL-18 secretion in human mononuclear leukocytes in vitro
- 2017
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Ingår i: Clinical and Experimental Dental Research. - : Wiley. - 2057-4347. ; 3:3, s. 115-120
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to investigate if hydrogen sulfide (H2S) induces the formation of the NLRP3 inflammasome and subsequent IL-1 beta and IL-18 secretion in human peripheral blood mononuclear cells (PBMCs) and in the human monocyte cell line THP1. Bacterial production of H2S has been suggested to participate in the inflammatory host response in periodontitis pathogenesis. H2S is a toxic gas with pro-inflammatory properties. It is produced by bacterial degradation of sulfur-containing amino acids, for example, cysteine. We hypothesize that H2S affects the inflammatory host response by inducing formation of the NLRP3 inflammasome and thereby causes the secretion of IL-1 beta and IL-18. PBMCs from eight healthy blood donors, the human monocyte cell line THP1 Null, and two variants of the THP1 cell line unable to form the NLRP3 inflammasome were cultured in the presence or absence of 1 mM sodium hydrosulfide (NaHS) in 24-well plates at 37 degrees C for 24 hr. Supernatants were collected and the IL-1 beta and IL-18 concentrations were measured with DuoSet ELISA Development kit. PBMCs exposed to NaHS produced more IL-1 beta and IL-18 than unexposed control cells (p = .023 and p = .008, respectively). An increase of extracellular potassium ions (K+) inhibited the secretion of IL-1 beta and IL-18 (p = .008). Further, NaHS triggered the secretion of IL-1 beta and IL-18 in human THP1-Null monocytes (p = .0006 and p = .002, respectively), while the NaHS-dependent secretion was reduced in the monocyte cell lines unable to form the NLRP3 inflammasome. Hence, the results suggest that NaHS induces the formation of the NLRP3 inflammasome and thus the secretion of IL-1 beta and IL-18. Enhanced NLRP3 inflammasome-dependent secretion of IL-1 beta and IL-18 in human mononuclear leukocytes exposed to NaHS in vitro is reported. This may be a mode for H2S to contribute to the inflammatory host response and pathogenesis of periodontal disease.
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| 7. |
- Basic, Amina, et al.
(författare)
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Hydrogen sulfide production from subgingival plaque samples.
- 2015
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Ingår i: Anaerobe. - : Elsevier BV. - 1095-8274 .- 1075-9964. ; 35:Part A, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95±6.6%). Fifty-six percent had moderate periodontal breakdown (CAL>3<7mm) and 35% had severe periodontal breakdown (CAL>7mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p=0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p=0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket.
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| 8. |
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| 9. |
- Basic, Amina, et al.
(författare)
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The proteins of Fusobacterium spp. involved in hydrogen sulfide production from L-cysteine
- 2017
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Ingår i: Bmc Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 17:61
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hydrogen sulfide (H2S) is a toxic foul-smelling gas produced by subgingival biofilms in patients with periodontal disease and is suggested to be part of the pathogenesis of the disease. We studied the H2S-producing protein expression of bacterial strains associated with periodontal disease. Further, we examined the effect of a cysteine-rich growth environment on the synthesis of intracellular enzymes in F. nucleatum polymorphum ATCC 10953. The proteins were subjected to one-dimensional (1DE) and two-dimensional (2DE) gel electrophoresis An in-gel activity assay was used to detect the H2S-producing enzymes; Sulfide from H2S, produced by the enzymes in the gel, reacted with bismuth forming bismuth sulfide, illustrated as brown bands (1D) or spots (2D) in the gel. The discovered proteins were identified with liquid chromatography - tandem mass spectrometry (LC-MS/MS). Results: Cysteine synthase and proteins involved in the production of the coenzyme pyridoxal 5'phosphate (that catalyzes the production of H2S) were frequently found among the discovered enzymes. Interestingly, a higher expression of H2S-producing enzymes was detected from bacteria incubated without cysteine prior to the experiment. Conclusions: Numerous enzymes, identified as cysteine synthase, were involved in the production of H2S from cysteine and the expression varied among Fusobacterium spp. and strains. No enzymes were detected with the in-gel activity assay among the other periodontitis-associated bacteria tested. The expression of the H2S-producing enzymes was dependent on environmental conditions such as cysteine concentration and pH but less dependent on the presence of serum and hemin.
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| 10. |
- Blomqvist, Susanne, 1953, et al.
(författare)
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Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus
- 2015
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Ingår i: Journal of Oral Microbiology. - : Informa UK Limited. - 2000-2297. ; 7:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. Materials and methods: A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins) and sea, seb, sec, tst, eta, etb, pvl (toxins). MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. Results: While the hemolytic phenotype was significantly (p<0.001) more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL) genotype was found in 73-100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIVpositives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillinresistant S. aureus (MRSA) strains were identified, two from oral infections and one from a Thai HIV patient. Conclusions: S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral infections and complaints and the antibiotic susceptibility (including MRSA) should regularly be checked. The frequent presence of S. aureus, although in low numbers among students and staff, emphasizes the importance of standard infection control precautions and of using diagnostic test in the dental clinic. © 2015 Susanne Blomqvist et al.
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