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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Nouveaux ciments acryliques inhibiteurs de l'adhérence bactérienne / New acrylic cements with bacterial adherence inhibition

Bauer, Thomas 24 March 2016 (has links)
La survenue d’une infection sur prothèse articulaire demeure une complication redoutable conduisant le plus souvent au changement de l’implant avec des risques de séquelles fonctionnelles et un impact socio-économique important. La lutte contre l’adhérence bactérienne au moment de la mise en place de l’implant représente une des voies de recherche pour la prévention de ces infections.L’objectif principal de cette étude était la mise au point de ciments acryliques modifiés par l’ajout de polymères et l’analyse in vitro de leur efficacité sur l’inhibition de l’adhérence bactérienne à leur surface.Les analyses d’adhérence bactérienne ont été réalisées avec du ciment acrylique commercialisé (CERAFIX® et CERAFIXGENTA® - société CERAVER – Roissy – France)associé à du polymère (polyNaSS) puis à des copolymères (MMA/NaSS) à différents dosages. La souche bactérienne testée était du Staphylococcus aureus en système purifié(fibrinogène seul) et en milieu plasmatique. L’ajout de polyNaSS, même en faible pourcentage, apporte au ciment un effet inhibiteur très important (entre 20 et 40% d’inhibition selon les mélanges). Les mélanges des ciments avec des copolymères MMA/ NaSS ont des propriétés d’inhibition de l’adhérence bactérienne plus faibles (environ 11%), avec un effet inhibiteur qui suit un modèle linaire d’inhibition dépendant de la quantité de copolymère dans le mélange. Ces mélanges sont biocompatibles et ne conduisent pas à des modifications de la morphologie des ostéoblastes.Les résultats obtenus permettent de montrer que le ciment CERAFIXGENTA® n’a pas un effet bactéricide immédiat et ne conduit pas à une inhibition de l’adhérence de bactéries sur les ciments. L’évaluation chimique a permis de préciser l’importance du relargage des polymères surtout dans les 24 premières heures indiquant un effet maximal immédiat et limité dans le temps sur l’adhérence bactérienne ce qui est l’objectif de cette prophylaxie. Ce relargage semble cependant entraîner des modifications architecturales du ciment avec augmentation de la porosité. Les observations en microscopie électronique des mélanges montrent des hétérogénéités de surfaces avec la présence des zones de porosité augmentée dues à la présence de copolymères. Ces observations semblent indiquer que bien que cette stratégie de prévention de l'infection des arthroplasties semble être très attrayante et fiable, les modifications mécaniques sur les surfaces d’implants pourraient conduire à l'échec précoce de l’arthroplastie avec descellement. L’étude biomécanique sur les différents mélanges de ciment et de polymères est nécessaire afin de préciser l’influence de la présence aussi bien du polyNaSS que des copolymères MMA/NaSS sur les qualités mécaniques du ciment. Ces85études permettront aussi de trouver le dosage optimal à obtenir pour maintenir les caractéristiques mécaniques du ciment tout en conservant les propriétés antiadhésives. / Résumé e anglais non fourni
2

Characterisation of lipoprotieins of Clostridium difficile and their role in virulence

Kovacs-Simon, Andrea January 2013 (has links)
Antibiotic-associated diarrhoea (AAD) and colitis, with the causative agent being the Gram-positive anaerobe, Clostridium difficile, are some of the most important hospital-acquired infections and significant burdens to healthcare services worldwide. Treatment of the infection is often ineffective and currently no vaccine is available against C. difficile infection (CDI). Research to identify novel virulence factors potentially leads to the development of new therapeutic and prophylactic drugs. As lipoproteins have been shown to play key roles in the virulence of several pathogens, the aim of this project was to investigate whether lipoproteins are involved in the virulence of C. difficile. Lipoproteins are anchored to the extracellular side of the cytoplasmic membrane in Gram-positive bacteria. Two enzymes are involved in the biosynthesis of lipoproteins: lipoprotein diacylglycerol transferase (Lgt) attaches lipoproteins to the membrane, and lipoprotein signal peptidase (Lsp) cleaves the signal peptide from the amino-terminus of lipoproteins. In order to study lipoprotein processing in C. difficile, lgt and lsp mutants of the C. difficie 630Δerm strain were generated using the ClosTron system. Antibody reactivity of 14 C. difficile lipoproteins was also investigated. It was shown in this study that lgt mutation caused changes in the lipoproteome of C. difficile. Therefore, inactivation of the lgt gene allowed investigation of the global contribution of lipoproteins to bacterial processes. The physiology and virulence of the lgt mutant was studied in vitro and in vivo. Surprisingly, many of the assayed phenotypes were not significantly affected by disruption of the lgt gene. Nevertheless, the ability of the lgt mutant to adhere to Caco-2 cells was markedly reduced. In addition, the phenotype of the lgt mutant observed in mice suggests that the faecal shedding of C. difficile is affected by Lgt inactivation. In further studies, the CD0873 lipoprotein as a potential adhesin of C. difficile was identified by in silico approach. Contribution of the CD0873 lipoprotein to the adherence of C. difficle was investigated by several different assays and the results strongly suggest that the CD0873 lipoprotein is directly involved in adhesion
3

Aderência bacteriana e formação de biofilme aos fios de dermossustentação facial / Bacterial adherence and biofilm formation on facial lifting threads

Leite, Bruna de Arruda 03 July 2008 (has links)
A flacidez e as rugas de expressão podem ser amenizadas com lifting facial ou implante no tecido subcutâneo da face de fios de poliuretano ou polipropileno. Sob determinadas condições microrganismos podem aderir sobre os fios e interagir com essas superfícies iniciando crescimento celular. O objetivo do presente estudo foi avaliar a aderência bacteriana aos fios de poliuretano e polipropileno por meio de microscopia eletrônica de varredura e métodos microbiológicos. Os fios foram seccionados em segmentos de 1,0 cm de comprimento e transferidos individualmente para tubos Falcon (50,0 mL) contendo caldo Mueller Hinton (15,0 mL), com 200 \'mü\'L da suspensão bacteriana (\'10 POT.8\' UFC/mL) preparada e, incubados por 1h e 30 minutos, 4, 24, 48, 72 e 120 horas. Após cada período de incubação, os corpos-de-prova foram lavados três vezes e introduzidos, separadamente, em 5,0 mL de solução salina esterilizada, sonicados a 40 kHZ por 8 minutos e homogeneizados em vortex por 10 segundos. Esta solução foi diluída (1/10 a 1/1000), da diluição 1/1000 uma alíquota de 0,1 mL foi plaqueada sobre Tryptic Soy Agar (TSA). As placas foram incubadas a 37 graus Celsius por 18 a 24 horas. Após o período de incubação, as células viáveis foram contadas e o resultado anotado em termos de unidades formadoras de colônia (UFC/mL). Os corpos-de-prova destinados à observação por microscópio eletrônico de varredura foram fixados em glutaraldeído, desidratados em séries de álcool, secos em centrífuga a vácuo metalizados com ouro. A avaliação quantitativa do crescimento de S. aureus sobre a superfície do poliuretano, após 1 hora e 30 minutos de contato, foi 4,0 \'+ OU -\' 0,0 log UFC/mL, S. epidermidis 4,07 \'+ OU -\' 0,10 log UFC/mL e P. aeruginosa 5,08 \'+ OU -\' 0,1410 log UFC/mL. Após 4-120 horas o número de células viáveis de S. aureus sobre a superfície do poliuretano foi 5,49 \'+ OU -\' 0,04 log UFC/mL, S. epidermidis 4,99 \'+ OU -\' 0,07 log UFC/mL e P. aeruginosa 6,52 \'+ OU -\' 0,03 log UFC/mL. A avaliação quantitativa do crescimento de S. aureus sobre a superfície do polipropileno, após 1 hora e 30 minutos de contato, foi 4,24 \'+ OU -\' 0,0 log UFC/mL, S. epidermidis 4,14 \'+ OU -\' 0,14 log UFC/mL e P. aeruginosa 5,77 \'+ OU -\' 0,05 log UFC/mL. Após 4 - 120 horas o número de células viáveis de S. aureus sobre a superfície do polipropileno o número de células viáveis de S. aureus foi de 5,96 \'+ OU -\' 0,07 log UFC/mL, S. epidermidis 4,96 \'+ OU -\' 0,06 log UFC/mL e P. aeruginosa 6,63 \'+ OU -\' 0,05 log UFC/mL. O número de células viáveis de S. aureus, S. epidermidis e P. aeruginosa sobre as superfícies de poliuretano e polipropileno foram significantemente diferentes (p<0,05). O biofilme foi observado sobre ambos fios (poliuretano e polipropileno) como demonstrado por meio de microscopia eletrônica de varredura. / Flabbiness and expression wrinkles can be helped by undergoing a face lifting or by implanting subcutaneous tissues of polyurethane or polypropylene threads. Under certain conditions microorganisms can attach themselves to the threads and interact with these surfaces initiating cellular growth. The goal of the present study was to evaluate bacterial attachment to polyurethane and polypropylene threads by means of scanning electron microscopy and microbiological method. The threads were sectioned into segments of 1.0 cm in length and inserted, one by one, into separated Falcon tubes (50 mL) containing Mueller Hinton broth (15 mL), with 200 \'mü\'L of the bacterial suspension (\'10 POT.8\' CFU/mL) prepared, and incubated for 1 hour and 30 minutes, at 4, 24, 48, 72 and 120 hour periods. After each incubation period, the coupons were rinsed three times and, inserted, one by one, into 5.0 mL of sterile physiological saline solution, sonicated at 40 kHz for 8 minutes and vortexed for 10 seconds. This solution was diluted three-fold (1/10 to 1/1000), from dilution the 1/1000 dilution an aliquot of 0.1 mL was plated onto Tryptic Soy agar (TSA). The plates were incubated at 37 Celsius degrees from 18 to 24 h. After the incubation periods, the viable bacteria were counted and the results noted in terms of colony forming units (CFU/mL). The coupons destined for scanning electron microscopy observations were fixed in glutaraldehyde, dehydrated in alcohol series, dried in vacuum centryfuge and metalized with gold. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polyurethane, after 1h and 30 minutes of contact, the results shown 4.0 \'+ OU -\' 0.0 CFU/mL, S. epidermidis 4.07 \'+ OU -\' 0.1 CFU/mL and P. aeruginosa 5.08 \'+ OU -\' 0.14 CFU/mL. After 4 - 120 h the number of viable cells of S. aureus on polyurethane surfaces were 5.49 \'+ OU -\' 0.04 CFU/mL, S. epidermidis 4.99 \'+ OU -\' 0.07 CFU/mL and P. aeruginosa 6.52 \'+ OU -\' 0.03 CFU/mL. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polypropylene after 1h and 30 minutes of contact, the results shown 4.24 \'+ OU -\' 0.20 CFU/mL, with S. epidermidis 4.14 \'+ OU -\' 0.1 CFU/mL and P. aeruginosa 5.77 \'+ OU -\' 0.05 CFU/mL. After 4 - 120 h the number of viable cells of S. aureus on polypropylene surfaces were 5.96 \'+ OU -\' 0.07 CFU/mL, S. epidermidis 4.96 \'+ OU -\' 0.07 CFU/mL and P. aeruginosa 6.63 \'+ OU -\' 0.05 CFU/mL. The number of viable cells of S. aureus, S. epidermidis, P. aeruginosa on polyurethane and polypropylene surfaces were significantly different (p<0.05). A biofilm was observed on both threads (polyurethane and polypropylene) as demonstrated by scanning electron microscopy.
4

Aderência bacteriana e formação de biofilme aos fios de dermossustentação facial / Bacterial adherence and biofilm formation on facial lifting threads

Bruna de Arruda Leite 03 July 2008 (has links)
A flacidez e as rugas de expressão podem ser amenizadas com lifting facial ou implante no tecido subcutâneo da face de fios de poliuretano ou polipropileno. Sob determinadas condições microrganismos podem aderir sobre os fios e interagir com essas superfícies iniciando crescimento celular. O objetivo do presente estudo foi avaliar a aderência bacteriana aos fios de poliuretano e polipropileno por meio de microscopia eletrônica de varredura e métodos microbiológicos. Os fios foram seccionados em segmentos de 1,0 cm de comprimento e transferidos individualmente para tubos Falcon (50,0 mL) contendo caldo Mueller Hinton (15,0 mL), com 200 \'mü\'L da suspensão bacteriana (\'10 POT.8\' UFC/mL) preparada e, incubados por 1h e 30 minutos, 4, 24, 48, 72 e 120 horas. Após cada período de incubação, os corpos-de-prova foram lavados três vezes e introduzidos, separadamente, em 5,0 mL de solução salina esterilizada, sonicados a 40 kHZ por 8 minutos e homogeneizados em vortex por 10 segundos. Esta solução foi diluída (1/10 a 1/1000), da diluição 1/1000 uma alíquota de 0,1 mL foi plaqueada sobre Tryptic Soy Agar (TSA). As placas foram incubadas a 37 graus Celsius por 18 a 24 horas. Após o período de incubação, as células viáveis foram contadas e o resultado anotado em termos de unidades formadoras de colônia (UFC/mL). Os corpos-de-prova destinados à observação por microscópio eletrônico de varredura foram fixados em glutaraldeído, desidratados em séries de álcool, secos em centrífuga a vácuo metalizados com ouro. A avaliação quantitativa do crescimento de S. aureus sobre a superfície do poliuretano, após 1 hora e 30 minutos de contato, foi 4,0 \'+ OU -\' 0,0 log UFC/mL, S. epidermidis 4,07 \'+ OU -\' 0,10 log UFC/mL e P. aeruginosa 5,08 \'+ OU -\' 0,1410 log UFC/mL. Após 4-120 horas o número de células viáveis de S. aureus sobre a superfície do poliuretano foi 5,49 \'+ OU -\' 0,04 log UFC/mL, S. epidermidis 4,99 \'+ OU -\' 0,07 log UFC/mL e P. aeruginosa 6,52 \'+ OU -\' 0,03 log UFC/mL. A avaliação quantitativa do crescimento de S. aureus sobre a superfície do polipropileno, após 1 hora e 30 minutos de contato, foi 4,24 \'+ OU -\' 0,0 log UFC/mL, S. epidermidis 4,14 \'+ OU -\' 0,14 log UFC/mL e P. aeruginosa 5,77 \'+ OU -\' 0,05 log UFC/mL. Após 4 - 120 horas o número de células viáveis de S. aureus sobre a superfície do polipropileno o número de células viáveis de S. aureus foi de 5,96 \'+ OU -\' 0,07 log UFC/mL, S. epidermidis 4,96 \'+ OU -\' 0,06 log UFC/mL e P. aeruginosa 6,63 \'+ OU -\' 0,05 log UFC/mL. O número de células viáveis de S. aureus, S. epidermidis e P. aeruginosa sobre as superfícies de poliuretano e polipropileno foram significantemente diferentes (p<0,05). O biofilme foi observado sobre ambos fios (poliuretano e polipropileno) como demonstrado por meio de microscopia eletrônica de varredura. / Flabbiness and expression wrinkles can be helped by undergoing a face lifting or by implanting subcutaneous tissues of polyurethane or polypropylene threads. Under certain conditions microorganisms can attach themselves to the threads and interact with these surfaces initiating cellular growth. The goal of the present study was to evaluate bacterial attachment to polyurethane and polypropylene threads by means of scanning electron microscopy and microbiological method. The threads were sectioned into segments of 1.0 cm in length and inserted, one by one, into separated Falcon tubes (50 mL) containing Mueller Hinton broth (15 mL), with 200 \'mü\'L of the bacterial suspension (\'10 POT.8\' CFU/mL) prepared, and incubated for 1 hour and 30 minutes, at 4, 24, 48, 72 and 120 hour periods. After each incubation period, the coupons were rinsed three times and, inserted, one by one, into 5.0 mL of sterile physiological saline solution, sonicated at 40 kHz for 8 minutes and vortexed for 10 seconds. This solution was diluted three-fold (1/10 to 1/1000), from dilution the 1/1000 dilution an aliquot of 0.1 mL was plated onto Tryptic Soy agar (TSA). The plates were incubated at 37 Celsius degrees from 18 to 24 h. After the incubation periods, the viable bacteria were counted and the results noted in terms of colony forming units (CFU/mL). The coupons destined for scanning electron microscopy observations were fixed in glutaraldehyde, dehydrated in alcohol series, dried in vacuum centryfuge and metalized with gold. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polyurethane, after 1h and 30 minutes of contact, the results shown 4.0 \'+ OU -\' 0.0 CFU/mL, S. epidermidis 4.07 \'+ OU -\' 0.1 CFU/mL and P. aeruginosa 5.08 \'+ OU -\' 0.14 CFU/mL. After 4 - 120 h the number of viable cells of S. aureus on polyurethane surfaces were 5.49 \'+ OU -\' 0.04 CFU/mL, S. epidermidis 4.99 \'+ OU -\' 0.07 CFU/mL and P. aeruginosa 6.52 \'+ OU -\' 0.03 CFU/mL. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polypropylene after 1h and 30 minutes of contact, the results shown 4.24 \'+ OU -\' 0.20 CFU/mL, with S. epidermidis 4.14 \'+ OU -\' 0.1 CFU/mL and P. aeruginosa 5.77 \'+ OU -\' 0.05 CFU/mL. After 4 - 120 h the number of viable cells of S. aureus on polypropylene surfaces were 5.96 \'+ OU -\' 0.07 CFU/mL, S. epidermidis 4.96 \'+ OU -\' 0.07 CFU/mL and P. aeruginosa 6.63 \'+ OU -\' 0.05 CFU/mL. The number of viable cells of S. aureus, S. epidermidis, P. aeruginosa on polyurethane and polypropylene surfaces were significantly different (p<0.05). A biofilm was observed on both threads (polyurethane and polypropylene) as demonstrated by scanning electron microscopy.
5

Type V Secretion System Exoproteins and their Roles in the Adherence of the Gram-Negative Bacterial Pathogens Moraxella catarrhalis, Burkholderia pseudomallei and Burkholderia mallei

Balder, Rachel 25 September 2007 (has links)
No description available.
6

Análise in vitro do efeito do monômero antibacteriano MDPB sobre a adesão bacteriana à resina composta / Influence of the MDPB monomer on the in vitro bacterial adherence to resin composite

Thomé, Thaís 02 June 2005 (has links)
Um novo monômero, brometo de metacriloiloxidodecilpiridínio (MDPB), com efeito antibacteriano e capacidade de co-polimerizar com outros monômeros, foi apresentado por Imazato, Torii e Tsuchitani (1993). Este estudo avaliou a adesão bacteriana, em 16, 40 e 64 horas, à resina composta contendo ou não o monômero antibacteriano MDPB. A adesão foi testada para Streptococcus sanguinis e Streptococcus sobrinus. Após as amostras terem sido submetidas à incubação, o biofilme foi coletado e a contagem de UFCs foi realizada. Os dados foram comparados pelo método ANOVA complementado por teste de Tukey. Os resultados demonstraram que, para o S. sanguinis, a adesão sobre o MDPB foi significativamente maior (p<0.05) quando comparado ao controle em 16 horas, mas diminuiu significativamente em 40 horas, não apresentando diferenças quando comparado ao controle neste tempo (p<0.01). Para o S. sobrinus, o controle apresentou aumento significativo da adesão bacteriana em 64 horas quando comparado com 16 horas (p<0.01), sendo significativamente maior que para o MDPB em 64 horas (p<0.05). Assim, o estudo mostrou que o MDPB é capaz de inibir a adesão de S. sobrinus sem interferir na adesão do S. sanguinis. Portanto, nas condições deste estudo os resultados sugerem que a incorporação do MDPB a resinas compostas pode ser de importância na prevenção de cáries secundárias favorecendo a adesão de bactérias comensais em detrimento de bactérias com potencial cariogênico. / A new antibacterial monomer, Methacryloyloxydodecylpyridinium bromide (MDPB), with antibacterial property and ability to co-polymerize with other monomers, was introduced by Imazato, Torii and Tsuchitani (1993). This study aimed to analyze the effect of MDPB on bacterial adherence to resin composites containing or not MDPB. Streptococcus sanguinis and Streptococcus sobrinus were used. The biofilms were collected from the samples and the colony forming units (CFUs) were counted after 16, 40 e 64 h of incubation. The data were compared by ANOVA complemented by the Tukey’s test. The results showed that the adhesion of S. sanguinis to MDPB-containing resin composite was significantly higher (p<0.05) than to control samples at 16 h, but significantly diminished at 40 h, reaching values similar to those of control samples (p<0.01). The adherence of S. sobrinus to control samples significantly increased throughout the experimental time (p<0.01) and was considerably higher than to MDPB at 64 h (p<0.05). Thus, the study showed that MDPB is capable of inhibit adhesion of S. sobrinus with no interference on the adhesion of S. sanguinis. Thus, at the conditions of this study we suggest that MDPB incorporated to resin composites could be of importance to prevent secondary caries favoring adhesion of commensal bacteria and impairing adhesion of cariogenic bacteria.
7

Diversity and adaptation in the adherence properties of Helicobacter pylori

Méndez, Melissa January 2014 (has links)
No description available.
8

Análise in vitro do efeito do monômero antibacteriano MDPB sobre a adesão bacteriana à resina composta / Influence of the MDPB monomer on the in vitro bacterial adherence to resin composite

Thaís Thomé 02 June 2005 (has links)
Um novo monômero, brometo de metacriloiloxidodecilpiridínio (MDPB), com efeito antibacteriano e capacidade de co-polimerizar com outros monômeros, foi apresentado por Imazato, Torii e Tsuchitani (1993). Este estudo avaliou a adesão bacteriana, em 16, 40 e 64 horas, à resina composta contendo ou não o monômero antibacteriano MDPB. A adesão foi testada para Streptococcus sanguinis e Streptococcus sobrinus. Após as amostras terem sido submetidas à incubação, o biofilme foi coletado e a contagem de UFCs foi realizada. Os dados foram comparados pelo método ANOVA complementado por teste de Tukey. Os resultados demonstraram que, para o S. sanguinis, a adesão sobre o MDPB foi significativamente maior (p<0.05) quando comparado ao controle em 16 horas, mas diminuiu significativamente em 40 horas, não apresentando diferenças quando comparado ao controle neste tempo (p<0.01). Para o S. sobrinus, o controle apresentou aumento significativo da adesão bacteriana em 64 horas quando comparado com 16 horas (p<0.01), sendo significativamente maior que para o MDPB em 64 horas (p<0.05). Assim, o estudo mostrou que o MDPB é capaz de inibir a adesão de S. sobrinus sem interferir na adesão do S. sanguinis. Portanto, nas condições deste estudo os resultados sugerem que a incorporação do MDPB a resinas compostas pode ser de importância na prevenção de cáries secundárias favorecendo a adesão de bactérias comensais em detrimento de bactérias com potencial cariogênico. / A new antibacterial monomer, Methacryloyloxydodecylpyridinium bromide (MDPB), with antibacterial property and ability to co-polymerize with other monomers, was introduced by Imazato, Torii and Tsuchitani (1993). This study aimed to analyze the effect of MDPB on bacterial adherence to resin composites containing or not MDPB. Streptococcus sanguinis and Streptococcus sobrinus were used. The biofilms were collected from the samples and the colony forming units (CFUs) were counted after 16, 40 e 64 h of incubation. The data were compared by ANOVA complemented by the Tukey’s test. The results showed that the adhesion of S. sanguinis to MDPB-containing resin composite was significantly higher (p<0.05) than to control samples at 16 h, but significantly diminished at 40 h, reaching values similar to those of control samples (p<0.01). The adherence of S. sobrinus to control samples significantly increased throughout the experimental time (p<0.01) and was considerably higher than to MDPB at 64 h (p<0.05). Thus, the study showed that MDPB is capable of inhibit adhesion of S. sobrinus with no interference on the adhesion of S. sanguinis. Thus, at the conditions of this study we suggest that MDPB incorporated to resin composites could be of importance to prevent secondary caries favoring adhesion of commensal bacteria and impairing adhesion of cariogenic bacteria.
9

Effect of Conventional Mouthrinses on Initial Bioadhesion to Enamel and Dentin in situ

Hannig, C., Gaeding, A., Basche, S., Richter, G., Helbig, R., Hannig, M. 04 August 2020 (has links)
Aim: The study aimed to investigate the effect of a customary fluoride solution, containing sodium fluoride and amine fluoride, on initial biofilm formation on enamel and dentin in situ compared directly to chlorhexidine. Methods: Bovine enamel and dentin specimens were mounted on maxillary splints carried by 9 subjects. After 1 min of pellicle formation, rinses with tap water (control), chlorhexidine (meridol med CHX 0.2%, GABA) and a fluoride mouthrinse (elmex, GABA) were performed for 1 min. Subsequently, the slabs were carried for another 8 h. The adherent bacteria were determined by DAPI staining, live-dead staining and determination of colony-forming units after desorption; glucan formation was visualized with concanavalin A. Additionally, energy-dispersive X-ray spectroscopy (EDX) analysis of the in situ biofilm layers was conducted, and contact angle measurements were performed. Statistical evaluation was performed by means of the Kruskal-Wallis test followed by the Mann-Whitney U test (p < 0.05). Results: In the control group, significantly higher amounts of adherent bacteria were detected on dentin (4.8 x 10⁶ ± 5.4 x 10⁶ bacteria/cm²) than on enamel (1.2 x 10⁶ ± 1.5 x 10⁶ bacteria/cm² , DAPI). Chlorhexidine significantly reduced the amount of adherent bacteria (dentin: 2.8 x 10⁵ ± 3.4 x 10⁵ bacteria/cm² ; enamel: 4.2 x 10⁵ ± 8.7 x 10⁵ bacteria/cm²). Rinses with the fluoride solution also significantly reduced bacterial adherence to dentin (8.1 x 10⁵ ± 1.5 x 10⁶ bacteria/cm²). Fluoride could not be detected by EDX analysis of the biofilms. Fluoride mouthrinsing did not influence the wettability of the pellicle-covered enamel surface. Conclusion: In addition to the reduction of demineralization and antibacterial effects, fluorides inhibit initial biofilm formation on dental hard tissues considerably, especially on dentin.
10

Aderência bacteriana: estudo in vitro de superfície de aço inoxidável e liga de titânio-alumínio-vanádio de uso ortopédico / Bacterial adherence: an in vitro study of stainless steel and titanium-aluminium-vanadium alloy surfaces of orthopedic use

Basso, Ana Cristina 24 June 2009 (has links)
O uso de metais na fabricação de implantes ortopédicos iniciou-se nas primeiras décadas do século XX. O aumento do uso de biomateriais implantáveis aumentam também os casos de infecção. A colonização da superfície do biomaterial pode ter início no momento da inserção do corpo estranho no organismo e geralmente é causada por microrganismos da microbiota da pele ou região adjacente ao implante. Este estudo teve por objetivo avaliar por métodos microbiológicos e microscópio eletrônico de varredura (MEV), a aderência bacteriana à superfície de aço inoxidável e liga de titânio de uso médico, bem como a molhabilidade da superfície destes metais. As bactérias usadas foram Staphylococcus epidermidis ATCC 12228 e Staphylococcus aureus ATCC 25923. Os discos de aço inoxidável (15,0 mm de diâmetro x 2,0 mm de espessura) e de liga de titânio (12,0 mm de diâmetro x 2,0 mm de espessura) foram inseridos, asséptica e separadamente, em tubos contendo 15,0 mL de caldo Mueller Hinton e 200,0 \'mü\'L de suspensão bacteriana da ordem de \'10 POT.8\' UFC/mL. Cada bactéria foi estudada individualmente. Os tubos foram incubados por 1, 6, 24, 48 e 72 horas sob agitação a 37 graus Celsius. Após os períodos de incubação, os discos foram retirados do caldo de cultura e submetidos ao banho de ultrassom em 5,0 mL de solução fisiológica 0,85% esterilizada. Deste líquido, foram realizadas diluições da ordem de \'10 POT.-1\' a \'10 POT.-4\' para a quantificação de células viáveis. Os valores foram expressos em UFC/mL. Para S. epidermidis sobre a liga de titânio, o número de células viáveis foi em 1 hora: 7,20 x \'10 POT.4\'; 6 horas: 3,90 x \'10 POT.6\'; 24 horas: 3,80 x \'10 POT.6\'; 48 horas: 9,70 x \'10 POT.6\' e 72 horas: 1,00 x \'10 POT.7\'. Sobre o aço inoxidável, o número de células viáveis foi em 1 hora: 3,00 x \'10 POT.3\'; 6 horas: 2,90 x \'10 POT.6\'; 24 horas: 3,20 x \'10 POT.6\'; 48 horas: 1,41 x \'10 POT.7\' e 72 horas: 1,88 x \'10 POT.7\'. Para S. aureus ) sobre a liga de titânio, o número de células viáveis foi em 1 hora: 2,00 x \'10 POT.3\'; 6 horas: 1,00 x \'10 POT.4\'; 24 horas: 3,10 x \'10 POT.4\'; 48 horas: 4,30 x \'10 POT.4\' e 72 horas: 5,80 x \'10 POT.3\'. Sobre o aço inoxidável, o número de células viáveis foi em 1 hora: 6,00 x \'10 POT.3\'; 6 horas: 2,00 x \'10 POT.3\'; 24 horas: 1,50 x \'10 POT.4\'; 48 horas: 3,20 x \'10 POT.5\' e 72 horas: 6,00 x \'10 POT.3\'. Ambas as superfícies metálicas foram caracterizadas como de média molhabilidade, onde a liga de titânio teve média \'+ OU -\' desvio padrão de 39,016 \'+ OU -\' 11,267 e o aço inoxidável 58,083 \'+ OU -\' 7,165. Tanto o S. aureus quanto o S. epidermidis aderiram às superfícies dos biomateriais estudados, como foi observado por meio de MEV. Com base nos resultados é possível concluir que os dois microrganismos são capazes de aderir a superfícies metálicas. Isto aumenta a preocupação quanto à patogênese das infecções relacionadas a implantes ortopédicos, uma vez que esses microrganismos estão presentes na pele humana e oferecem o risco de reações inflamatórias e infecção, promovendo a perda do implante para efetivar a cura. / The utilization of metals in the manufacture of orthopedic implants started in first decades of twentieth century. The increased use of implantable biomaterials increased also infection cases. Biomaterial surface colonization can start at the moment of foreign body insertion in the organism and is usually caused by microorganisms of skin microbiota or adjacent region to the implant. This study aimed to evaluate microbiological methods and scanning electron microscopy (SEM), the bacterial adhesion to surface of stainless steel and titanium alloy of medical use, as well as the surface wetability of these metals. The used bacteria were Staphylococcus epidermidis ATCC 12228 and Staphylococcus aureus ATCC 25923. The stainless steel (15,0 mm diameter x 2,0 mm thick) and titanium alloy (12,0 mm diameter x 2,0 mm thick) discs were inserted, aseptic and individually, into tubes containing 15,0 mL Mueller Hinton broth and 200,0 \'mü\'L of bacterial suspension with \'10 POT.8\' CFU/mL concentration. Each bacterium was individually studied. The tubes were incubated for 1, 6, 24, 48 and 72 hours under agitation at 37 Celsius degrees. After incubation periods, the discs were removed from culture broth and submitted to the ultrasound bath in 5,0 mL of sterile saline. From this liquid were realized dilutions of \'10 POT.-1\' to \'10 POT.-4\' to quantify the viable cells. Values were expressed in CFU/mL. S. epidermidis over titanium alloy viable cells number was in 1 hour: 7,20 x \'10POT.4\'; 6 hours: 3,90 x \'10 POT.6\'; 24 hours: 3,80 x \'10 POT.6\'; 48 hours: 9,70 x \'10 POT.6\' and 72 hours: 1,00 x \'10 POT.7\'. Over stainless steel viable cells number was in 1 hour: 3,00 x \'10 POT.3\'; 6 hours: 2,90 x \'10 POT.6\'; 24 hours: 3,20 x \'10 POT.6\'; 48 hours: 1,41 x \'10 POT.7\' and 72 hours: 1,88 x \'10 POT.7\'. To S. aureus over titanium alloy viable cells number was in 1 hour: 2,00 x \'10 POT.3\'; 6 hours: 1,00 x \'10 POT.4\'; 24 hours: 3,10 x \'10 POT.4\'; 48 hours: 4,30 x \'10 POT.4\' and 72 hours: 5,80 x \'10 POT.3\' and over stainless steel viable cells number was in 1 hour: 6,00 x \'10 POT.3\'; 6 hours: 2,00 x \'10 POT.3\'; 24 hours: 1,50 x \'10 POT.4\'; 48 hours: 3,20 x \'10 POT.5\' and 72 hours: 6,00 x \'10 POT.3\'. Both metal surfaces were characterized as medium wetability, where the contact angle of titanium alloy was mean \'+ OU -\' standard deviation 39,016 \'+ OU -\' 11,267 and stainless steel 58,083 \'+ OU -\' 7,165. Both S. aureus as S. epidermidis adhered to surfaces of biomaterials studied, as observed by SEM. Based on the results we concluded that two microorganisms are able to adhere to metal surfaces. This increases the concern about the pathogenesis of infections related to orthopedic implants, since these microorganisms are present in human skin and provide the risk of infection and inflammatory reactions, furthering implant loss to effective cure.

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