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1.
Braz. j. oral sci ; 20: e211060, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1254621

RESUMO

Aim: To evaluate the efficacy of ultrasonic bath and traditional brushing in the hygiene of complete dentures of dependent residents in long-term care institutions (LTCIs). Methods: A randomized cross-over clinical study was conducted in 17 maxillary complete denture wearers living in LTCIs. Cleaning protocols were brushing or ultrasonic bath, both applied with neutral liquid soap. Biofilm biomass were estimated by MTT reduction assay and specific microbial load (CFU) of Streptococcus spp., Staphylococcus spp. and Candida spp. were quantified by selective and differential culture media. Results: Ultrasound method showed higher percentage reduction of biofilm biomass and specific microbial loads of Streptococcus spp. compared to brushing (p<0.01). Reduction of microbial loads of the other microorganisms were not different between cleaning methods (p>0.05). Conclusions: The ultrasonic bath proved to be a feasible alternative method for the mechanical cleaning of complete dentures in LTCIs


Assuntos
Idoso , Higiene , Dentaduras , Biofilmes , Serviços de Saúde para Idosos
2.
Braz. j. oral sci ; 20: e212098, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1281101

RESUMO

Aim: This study aimed to evaluate the pH, Ca2+ release, solubility, and antimicrobial activity of calcium hydroxide (Ca(OH)2) pastes in association with different substances. Methods: Sixty acrylic teeth (n=10) were filled with pastes that associated Ca(OH)2 with the following substances: benzalkonium chloride 5% (G1) and 50% (G2) both in propylene glycol, arnica glycolic extract (G3), green tea glycolic extract (G4), Calen/PMCC™ (G5), and Calen™ (G6). In the group G1 to G4 were used 1g of Ca(OH)2 powder with 0,8g of vehicle. pH and Ca2+ release was measured after 7, 15, and 30 days. For solubility, micro-CT was used immediately and at the periods of 7, 15, and 30 days. For the antimicrobial analysis, a biofilm of E. faecalis was induced in vitro on bovine dentin discs. Live/dead viability dye and confocal scanning microscopy were used. Results: The highest pH values occurred on the first 7 days, and the G6, G1, G3, and G5 presented the highest pH values at this period (P <0.05). Ca2+ release was higher in all groups at 7 days, with the highest values observed in G1, G5, and G6. The volume of all pastes showed no significant difference in the intragroup analysis at 7 and 15 days (P <0.05). G1 and G2 showed the highest antimicrobial action (P <0.05). For the biovolume, there was difference between the G6 and the other groups (P >0.05) with G1 presenting the lowest values. Conclusion: Benzalkonium chloride 5% increases the antimicrobial action of the Ca(OH2), without impairs physicochemical properties


Assuntos
Materiais Restauradores do Canal Radicular , Hidróxido de Cálcio , Biofilmes , Fenômenos Químicos , Anti-Infecciosos
3.
Mater Sci Eng C Mater Biol Appl ; 127: 112225, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225870

RESUMO

Many medical and chemical applications require the precise supply of antimicrobial components in a controlled manner at the location of mature biofilm deposits. This work reports a facile strategy to fabricate nanoscale metal-organic frameworks (NMOFs) coencapsulating the antibacterial ligand (lysine carbon dots, Lys-CDs) and targeted drug (folic acid, FA) in one pot to improve antibiofilm efficiency against established biofilms. The resulting products are characterized by transmission electron microscopy, field-emission scanning electron microscopy, powder x-ray diffraction, and ultraviolet-visible spectroscopy. The results show that Lys-CDs could coordinate with Zn2+ and the adding of FA inhibits the coordination of Lys-CDs with central ions of Zn. The Lys-CDs and FA are successfully exposed with the NMOFs disintegrating in the acid environment of bacterial metabolites. We are surprised to find a sharp increase of reactive oxygen species (ROS) inside the bacterial cells by FA functionalizing NMOFs, which undoubtedly enhance the antibacterial and antibiofilm activity. The as-synthesized ZIF-8-based nanocomposites also show the peroxidase-like activity in an acid environment, and produce extremely active hydroxyl radicals resulting in the improved antibacterial and antibiofilm activity. The possible mechanisms of antibacterial activities indicate that the presence of FA is significant in the sense of targeting bacteria. This study shows a novel approach to construct acid stimulation supply system which may be helpful for the research of antibiofilms.


Assuntos
Ácido Fólico , Estruturas Metalorgânicas , Antibacterianos/farmacologia , Bactérias , Biofilmes , Espécies Reativas de Oxigênio
4.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34259620

RESUMO

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters.Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity.Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs.Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time-kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation.Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole.Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Contaminação de Equipamentos/prevenção & controle , Fluconazol/farmacologia , Sulfonamidas/farmacologia , Candida/classificação , Candida/fisiologia , Candidíase/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Oxiquinolina/farmacologia , Diálise Renal
5.
Front Cell Infect Microbiol ; 11: 686479, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34277471

RESUMO

Polymicrobial interactions with oral mucosal surfaces determine the health status of the host. While a homeostatic balance provides protection from oral disease, a dysbiotic polymicrobial community promotes tissue destruction and chronic oral diseases. How polymicrobial communities transition from a homeostatic to a dysbiotic state is an understudied process. Thus, we were interested to investigate this ecological transition by focusing on biofilm communities containing high abundance commensal species and low abundance pathobionts to characterize the host-microbiome interactions occurring during oral health. To this end, a multispecies biofilm model was examined using the commensal species Corynebacterium durum and Streptococcus sanguinis and the pathobiont Porphyromonas gingivalis. We compared how both single and multispecies biofilms interact with different oral mucosal and gingival cell types, including the well-studied oral keratinocyte cell lines OKF4/TERT-1and hTERT TIGKs as well as human primary periodontal ligament cells. While single species biofilms of C. durum, S. sanguinis, and P. gingivalis are all characterized by unique cytokine responses for each species, multispecies biofilms elicited a response resembling S. sanguinis single species biofilms. One notable exception is the influence of P. gingivalis upon TNF-α and Gro-α production in hTERT TIGKs cells, which was not affected by the presence of other species. This study is also the first to examine the host response to C. durum. Interestingly, C. durum yielded no notable inflammatory responses from any of the tested host cells, suggesting it functions as a true commensal species. Conversely, S. sanguinis was able to induce expression and secretion of the proinflammatory cytokines IL-6 and IL-8, demonstrating a much greater inflammatory potential, despite being health associated. Our study also demonstrates the variability of host cell responses between different cell lines, highlighting the importance of developing relevant in vitro models to study oral microbiome-host interactions.


Assuntos
Porphyromonas gingivalis , Streptococcus sanguis , Biofilmes , Corynebacterium , Humanos
6.
Rev Bras Enferm ; 74(3): e20200759, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-34287490

RESUMO

OBJECTIVES: to evaluate the microbial load and adherence of Escherichia coli in different areas of the surgical instrument surface exposed to experimental contamination over time. METHODS: experimental study in which fragments of crile forceps (serrated, rod and rack) were contaminated by immersion in Tryptic Soy Broth, containing 106 CFU/mL of E. coli, for 1, 2, 4, 6, 8, 12 and 24 hours. Microbial load and bacterial adherence were evaluated using microbiological culture and scanning electron microscopy, respectively. RESULTS: there was an increase in the microbial load on the surgical instrument, proportional to the contamination interval, ranging from 102 after 1 hour to 105 CFU/cm2 in 24 hours. The presence of exopolysaccharide was detected after two hours of contamination. CONCLUSIONS: microbial load and adhesion of E. coli increased over time, reaching 105 CFU/cm2 after 24 hours of contamination, starting biofilm formation after two hours.


Assuntos
Escherichia coli , Aço Inoxidável , Biofilmes , Contagem de Colônia Microbiana , Humanos , Instrumentos Cirúrgicos
7.
J Environ Manage ; 293: 112947, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34289594

RESUMO

Quorum sensing (QS), a microbial communication mechanism modulated by acyl homoserine lactone (AHL) molecules impacts biofilm formation in bioreactors. This study investigated the effects of temperature and immigration on AHL levels and biofouling in anaerobic membrane bioreactors. The hypothesis was that the immigrant microbial community would increase the AHL-mediated QS, thus stimulating biofouling and that low temperatures would exacerbate this. We observed that presence of immigrants, especially when exposed to low temperatures indeed increased AHL concentrations and fouling in the biofilms on the membranes. At low temperature, the concentrations of the main AHLs observed, N-dodecanoyl-L-homoserine lactone and N-decanoyl-L-homoserine lactone, were significantly higher in the biofilms than in the sludge and correlated significantly with the abundance of immigrant bacteria. Apparently low temperature, immigration and denser community structure in the biofilm stressed the communities, triggering AHL production and excretion. These insights into the social behaviour of reactor communities responding to low temperature and influx of immigrants have implications for biofouling control in bioreactors.


Assuntos
Emigração e Imigração , Percepção de Quorum , Anaerobiose , Biofilmes , Reatores Biológicos , Temperatura
8.
J Biol Regul Homeost Agents ; 35(3 Suppl. 1): 107-115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34289670

RESUMO

The aim of the present prospective study was to evaluate periodontal health and subgingival microbiological alterations in adolescents treated with fixed self ligating orthodontic brackets in comparison to subject without any orthodontic appliance. A total of 40 adolescents (23 females and 17 males; mean age: 13.2 ± 3.2 years) were included: 30 subjects with self ligating brackets (test group) and 10 patients without orthodontic appliances (control group). Follow-ups were as follows: T1 (1 month), T2 (3 months), T3 (6 months) from the beginning of the orthodontic therapy. Clinical parameters (plaque index, gingival index and clinical attachment level) were measured for every patient and a microbiological analysis was performed. Mann Whitney test was performed to evaluate clinical parameters between test and control group and Friedman test and Fisher test were adopted to evaluate intra group differences at different follow-ups. Student T-test was performed to compare clinical attachment level between the two groups. Significance level was set at p<0.05. No periodontal pathogens and no clinical attachment loss were found in the whole sample. A slightly higher plaque index and gingival inflammation were recorded in the test group in comparison to the controls.


Assuntos
Gengivite , Braquetes Ortodônticos , Adolescente , Biofilmes , Criança , Índice de Placa Dentária , Feminino , Humanos , Masculino , Índice Periodontal , Estudos Prospectivos
9.
Molecules ; 26(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198596

RESUMO

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Flavonoides/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Materiais Revestidos Biocompatíveis/química , Flavonoides/química , Lasers/normas , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Propriedades de Superfície
10.
Int J Mol Sci ; 22(13)2021 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-34199128

RESUMO

Flavobacterium johnsoniae forms a thin spreading colony on nutrient-poor agar using gliding motility. As reported in the first paper, WT cells in the colony were sparsely embedded in self-produced extracellular polymeric matrix (EPM), while sprB cells were densely packed in immature biofilm with less matrix. The colony surface is critical for antibiotic resistance and cell survival. We have now developed the Grid Stamp-Peel method whereby the colony surface is attached to a TEM grid for negative-staining microscopy. The images showed that the top of the spreading convex WT colonies was covered by EPM with few interspersed cells. Cells exposed near the colony edge made head-to-tail and/or side-to-side contact and sometimes connected via thin filaments. Nonspreading sprB and gldG and gldK colonies had a more uniform upper surface covered by different EPMs including vesicles and filaments. The EPM of sprB, gldG, and WT colonies contained filaments ~2 nm and ~5 nm in diameter; gldK colonies did not include the latter. Every cell near the edge of WT colonies had one or two dark spots, while cells inside WT colonies and cells in SprB-, GldG-, or GldK-deficient colonies did not. Together, our results suggest that the colony surface structure depends on the capability to expand biofilm.


Assuntos
Adesinas Bacterianas/genética , Biofilmes/crescimento & desenvolvimento , Matriz Extracelular/metabolismo , Flavobacterium/fisiologia , Adesinas Bacterianas/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Bacterianos/genética , Sistemas de Secreção Bacterianos/metabolismo , Flavobacterium/efeitos dos fármacos , Flavobacterium/ultraestrutura , Testes de Sensibilidade Microbiana , Mutação , Fenótipo
11.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201173

RESUMO

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.


Assuntos
Biofilmes/crescimento & desenvolvimento , Carbonatos/química , Ciprofloxacina/farmacologia , Escherichia coli/crescimento & desenvolvimento , Magnetismo , Nanocompostos/administração & dosagem , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacos
12.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201389

RESUMO

The objective of this study was to determine reactive oxygen species (ROS) produced by fagopyrin F-rich fraction (FFF) separated from Tartary buckwheat flower extract exposed to lights and to investigate its antibacterial photodynamic inactivation (PDI) against Streptococcus mutans and its biofilm. ROS producing mechanisms involving FFF with light exposure were determined using a spectrophotometer and a fluorometer. S. mutans and its biofilm inactivation after PDI treatment of FFF using blue light (BL; 450 nm) were determined by plate count method and crystal violet assay, respectively. The biofilm destruction by ROS produced from FFF after exposure to BL was visualized using confocal laser scanning microscopy (CLSM) and field emission scanning electron microscope (FE-SEM). BL among 3 light sources produced type 1 ROS the most when applying FFF as a photosensitizer. FFF exposed to BL (5 and 10 J/cm2) significantly more inhibited S. mutans viability and biofilm formation than FFF without the light exposure (p < 0.05). In the PDI of FFF exposed to BL (10 J/cm2), an apparent destruction of S. mutans and its biofilm were observed by the CLSM and FE-SEM. Antibacterial PDI effect of FFF was determined for the first time in this study.


Assuntos
Biofilmes/crescimento & desenvolvimento , Fagopyrum/química , Flores/química , Fármacos Fotossensibilizantes/farmacologia , Extratos Vegetais/farmacologia , Quinonas/farmacologia , Streptococcus mutans/crescimento & desenvolvimento , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Luz , Fotoquimioterapia , Streptococcus mutans/efeitos dos fármacos
13.
Int J Mol Sci ; 22(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202115

RESUMO

The literature indicates the existence of a relationship between rhamnolipids and bacterial biofilm, as well as the ability of selected bacteria to produce rhamnolipids and alginate. However, the influence of biosurfactant molecules on the mechanical properties of biofilms are still not fully understood. The aim of this research is to determine the effect of rhamnolipids concentration, CaCl2 concentration, and ionic cross-linking time on the mechanical properties of alginate hydrogels using a Box-Behnken design. The mechanical properties of cross-linked alginate hydrogels were characterized using a universal testing machine. It was assumed that the addition of rhamnolipids mainly affects the compression load, and the value of this parameter is lower for hydrogels produced with biosurfactant concentration below CMC than for hydrogels obtained in pure water. In contrast, the addition of rhamnolipids in an amount exceeding CMC causes an increase in compression load. In bacterial biofilms, the presence of rhamnolipid molecules does not exceed the CMC value, which may confirm the influence of this biosurfactant on the formation of the biofilm structure. Moreover, rhamnolipids interact with the hydrophobic part of the alginate copolymer chains, and then the hydrophilic groups of adsorbed biosurfactant molecules create additional calcium ion trapping sites.


Assuntos
Alginatos/química , Bactérias/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Glicolipídeos/química , Hidrogéis/química , Líquidos Iônicos/química , Algoritmos , Modelos Teóricos
14.
Int J Mol Sci ; 22(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202218

RESUMO

Periprosthetic joint infections (PJIs) caused by Staphylococcus aureus infection are difficult to treat due to antibiotic resistance. It is known that the biofilms from methicillin-resistant S. aureus (MRSA) promote expansion of myeloid-derived suppressor cells (MDSCs) to suppress T-cell proliferation and benefit bacterial infections. This study finds that GMI, a fungal immunomodulatory peptide isolated from Ganoderma microsporum, suppresses MDSC expansion to promote the proliferation of cytotoxic T cells. The enhancement is likely attributed to increased expression of IL-6 and TNF-α and reduction in ROS expression. Similar beneficial effects of GMI on the suppression of MDSC expansion and IL-6 expression are also observed in the whole blood and reduces the accumulation of MDSCs in the infected bone region in a mouse PJI infection model. This study shows that GMI is potentially useful for treating S. aureus-induced PJIs.


Assuntos
Ganoderma/química , Imunomodulação/efeitos dos fármacos , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Peptídeos/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Animais , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/etiologia , Artrite Infecciosa/metabolismo , Biofilmes/efeitos dos fármacos , Biomarcadores , Biópsia , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Masculino , Camundongos , Células Supressoras Mieloides/metabolismo , Peptídeos/química , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/tratamento farmacológico , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/metabolismo , Espécies Reativas de Oxigênio , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Linfócitos T/metabolismo
15.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202773

RESUMO

In recent years, antimicrobial photodynamic therapy (aPDT) has received increasing attention as a promising tool aimed at both treating microbial infections and sanitizing environments. Since biofilm formation on biological and inert surfaces makes difficult the eradication of bacterial communities, further studies are needed to investigate such tricky issue. In this work, a panel of 13 diaryl-porphyrins (neutral, mono- and di-cationic) was taken in consideration to photoinactivate Pseudomonas aeruginosa. Among cationic photosensitizers (PSs) able to efficiently bind cells, in this study two dicationic showed to be intrinsically toxic and were ruled out by further investigations. In particular, the dicationic porphyrin (P11) that was not toxic, showed a better photoinactivation rate than monocationic in suspended cells. Furthermore, it was very efficient in inhibiting the biofilms produced by the model microorganism Pseudomonas aeruginosa PAO1 and by clinical strains derived from urinary tract infection and cystic fibrosis patients. Since P. aeruginosa represents a target very difficult to inactivate, this study confirms the potential of dicationic diaryl-porphyrins as photo-activated antimicrobials in different applicative fields, from clinical to environmental ones.


Assuntos
Biofilmes/efeitos dos fármacos , Biofilmes/efeitos da radiação , Luz , Porfirinas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/efeitos da radiação , Antibacterianos/química , Antibacterianos/farmacologia , Cátions , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/química
16.
Molecules ; 26(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205355

RESUMO

Rottlerin is a natural product consisting of chalcone and flavonoid scaffolds, both of which have previously shown quorum sensing (QS) inhibition in various bacteria. Therefore, the unique rottlerin scaffold highlights great potential in inhibiting the QS system of Pseudomonas aeruginosa. Rottlerin analogues were synthesised by modifications at its chalcone- and methylene-bridged acetophenone moieties. The synthesis of analogues was achieved using an established five-step synthetic strategy for chalcone derivatives and utilising the Mannich reaction at C6 of the chromene to construct morpholine analogues. Several pyranochromene chalcone derivatives were also generated using aldol conditions. All the synthetic rottlerin derivatives were screened for QS inhibition and growth inhibition against the related LasR QS system. The pyranochromene chalcone structures displayed high QS inhibitory activity with the most potent compounds, 8b and 8d, achieving QS inhibition of 49.4% and 40.6% and no effect on bacterial growth inhibition at 31 µM, respectively. Both compounds also displayed moderate biofilm inhibitory activity and reduced the production of pyocyanin.


Assuntos
Acetofenonas/farmacologia , Benzopiranos/farmacologia , Produtos Biológicos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Flavonoides/farmacologia , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/efeitos dos fármacos , Piocianina/farmacologia
17.
J Contemp Dent Pract ; 22(2): 128-133, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34257170

RESUMO

AIM: To evaluate the antibacterial efficacy of calcium hydroxide (CH) with antibiotic combinations: daptomycin and gentamicin against Enterococcus faecalis (E. faecalis) dentinal biofilm. MATERIALS AND METHODS: Sixty freshly extracted single-rooted mandibular premolars were inoculated with E. faecalis(ATCC 29212) (n = 30) (group A) and clinical isolates (n = 30) (group B) for 3 weeks to form a biofilm. The tooth samples of groups A and B were randomly divided into three subgroups of 10 each, groups 1A and 1B (CH), groups 2A and 2B (CH+G), groups 3A and 3B (CH+D), depending on the medicaments to be placed for one week. The difference between initial and final CFU was calculated and statistically analyzed. RESULTS: Among the clinical isolates, CH-antibiotic combinations were more effective than CH alone, which was statistically significant (p = 0.006). CONCLUSION: The dentinal biofilm of clinical isolates of E. faecalis strains exhibited more reduction in bacterial colonies with CH in combination with antibiotics (D and G). CLINICAL SIGNIFICANCE: Daptomycin and gentamicin when used as an intra-canal medicament in combination with CH are effective in eliminating E. faecalis. Keywords: Calcium hydroxide, Daptomycin, Dentinal biofilm, E. faecalis, Gentamicin.


Assuntos
Hidróxido de Cálcio , Daptomicina , Antibacterianos/farmacologia , Biofilmes , Hidróxido de Cálcio/farmacologia , Daptomicina/farmacologia , Cavidade Pulpar , Dentina , Enterococcus faecalis , Gentamicinas/farmacologia , Irrigantes do Canal Radicular
18.
Molecules ; 26(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201401

RESUMO

The limited number of medicinal products available to treat of fungal infections makes control of fungal pathogens problematic, especially since the number of fungal resistance incidents increases. Given the high costs and slow development of new antifungal treatment options, repurposing of already known compounds is one of the proposed strategies. The objective of this study was to perform in vitro experimental tests of already identified lead compounds in our previous in silico drug repurposing study, which had been conducted on the known Drugbank database using a seven-step procedure which includes machine learning and molecular docking. This study identifies siramesine as a novel antifungal agent. This novel indication was confirmed through in vitro testing using several yeast species and one mold. The results showed susceptibility of Candida species to siramesine with MIC at concentration 12.5 µg/mL, whereas other candidates had no antifungal activity. Siramesine was also effective against in vitro biofilm formation and already formed biofilm was reduced following 24 h treatment with a MBEC range of 50-62.5 µg/mL. Siramesine is involved in modulation of ergosterol biosynthesis in vitro, which indicates it is a potential target for its antifungal activity. This implicates the possibility of siramesine repurposing, especially since there are already published data about nontoxicity. Following our in vitro results, we provide additional in depth in silico analysis of siramesine and compounds structurally similar to siramesine, providing an extended lead set for further preclinical and clinical investigation, which is needed to clearly define molecular targets and to elucidate its in vivo effectiveness as well.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Indóis/química , Indóis/farmacologia , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Simulação por Computador , Reposicionamento de Medicamentos/métodos , Ergosterol/metabolismo , Aprendizado de Máquina , Simulação de Acoplamento Molecular/métodos
19.
Front Cell Infect Microbiol ; 11: 670211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222041

RESUMO

The contamination of dental unit waterlines (DUWLs) is a serious problem and directly affects the dental care. This study aims to explore the microbial community of biofilm in DUWL from different specialties and investigate the associated factors. A total of 36 biofilm samples from 18 DUWL of six specialties (i.e., prosthodontics, orthodontics, pediatrics, endodontics, oral surgery, and periodontics) at two time points (i.e., before and after daily dental practice) were collected with a novel method. Genomic DNA of samples was extracted, and then 16S ribosomal DNA (rDNA) (V3-V4 regions) and ITS2 gene were amplified and sequenced. Kruskal-Wallis and Wilcoxon rank test were adopted for statistical analysis. Microbial community with high diversity of bacteria (631 genera), fungi (193 genera), and viridiplantae was detected in the biofilm samples. Proteobacteria was the dominant bacteria (representing over 65.74-95.98% of the total sequences), and the dominant fungi was Ascomycota (93.9-99.3%). Microorganisms belonging to multiple genera involved in human diseases were detected including 25 genera of bacteria and eight genera of fungi, with relative abundance of six genera over 1% (i.e., Acinetobacter, Pseudomonas, Enterobacter, Aspergillus, Candida, and Penicillium). The biofilm microbiome may be influenced by the characteristics of dental specialty and routine work to some extent. The age of dental chair unit and overall number of patients had the strongest impact on the overall bacteria composition, and the effect of daily dental practices (associated with number of patients and dental specialty) on the fungi composition was the greatest. For the first time, biofilm in DUWL related to dental specialty was comprehensively evaluated, with more abundance of bacterial and fungal communities than in water samples. Biofilm accumulation with daily work and multiple kinds of opportunistic pathogen emphasized the infectious risk with dental care and the importance of biofilm control.


Assuntos
Microbiota , Microbiologia da Água , Biofilmes , Criança , Contagem de Colônia Microbiana , Contaminação de Equipamentos , Humanos
20.
Front Cell Infect Microbiol ; 11: 694789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249781

RESUMO

Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of infecting distinct niches of the human body, including skin wounds and the lungs of cystic fibrosis patients. Eradication of P. aeruginosa infection is becoming increasingly difficult due to the numerous resistance mechanisms it employs. Adaptive resistance is characterized by a transient state of decreased susceptibility to antibiotic therapy that is distinct from acquired or intrinsic resistance, can be triggered by various environmental stimuli and reverted by removal of the stimulus. Further, adaptive resistance is intrinsically linked to lifestyles such as swarming motility and biofilm formation, both of which are important in infections and lead to multi-drug adaptive resistance. Here, we demonstrated that NtrBC, the master of nitrogen control, had a selective role in host colonization and a substantial role in determining intrinsic resistance to ciprofloxacin. P. aeruginosa mutant strains (ΔntrB, ΔntrC and ΔntrBC) colonized the skin but not the respiratory tract of mice as well as WT and, unlike WT, could be reduced or eradicated from the skin by ciprofloxacin. We hypothesized that nutrient availability contributed to these phenomena and found that susceptibility to ciprofloxacin was impacted by nitrogen source in laboratory media. P. aeruginosa ΔntrB, ΔntrC and ΔntrBC also exhibited distinct host interactions, including modestly increased cytotoxicity toward human bronchial epithelial cells, reduced virulence factor production and 10-fold increased uptake by macrophages. These data might explain why NtrBC mutants were less adept at colonizing the upper respiratory tract of mice. Thus, NtrBC represents a link between nitrogen metabolism, adaptation and virulence of the pathogen P. aeruginosa, and could represent a target for eradication of recalcitrant infections in situ.


Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Ciprofloxacina/farmacologia , Interações Hospedeiro-Patógeno , Humanos , Camundongos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética , Virulência
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