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1.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34544866

RESUMO

Genome evolution is an essential and stringently regulated aspect of biological fitness. For bacteria, natural competence is one of the principal mechanisms of genome evolution and is frequently subject to multiple layers of regulation derived from a plethora of environmental and physiological stimuli. Here, we present a regulatory mechanism that illustrates how such disparate stimuli can be integrated into the Streptococcus mutans natural competence phenotype. S. mutans possesses an intriguing, but poorly understood ability to coordinately control its independently regulated natural competence and bacteriocin genetic pathways as a means to acquire DNA released from closely related, bacteriocin-susceptible streptococci. Our results reveal how the bacteriocin-specific transcription activator BrsR directly mediates this coordination by serving as an anti-adaptor protein responsible for antagonizing the proteolysis of the inherently unstable, natural competence-specific alternative sigma factor ComX. This BrsR ability functions entirely independent of its transcription regulator function and directly modulates the timing and severity of the natural competence phenotype. Additionally, many of the DNA uptake proteins produced by the competence system were surprisingly found to possess adaptor abilities, which are employed to terminate the BrsR regulatory circuit via negative feedback. BrsR-competence protein heteromeric complexes directly inhibit nascent brsR transcription as well as stimulate the Clp-dependent proteolysis of extant BrsR proteins. This study illustrates how critical genetic regulatory abilities can evolve in a potentially limitless variety of proteins without disrupting their conserved ancestral functions. These unrecognized regulatory abilities are likely fundamental for transducing information through complex genetic networks.


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriocinas/metabolismo , Regulação Bacteriana da Expressão Gênica , Mapas de Interação de Proteínas , Streptococcus mutans/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Fatores de Transcrição/genética
2.
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
3.
Commun Biol ; 4(1): 846, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34267305

RESUMO

Dental plaques are biofilms that cause dental caries by demineralization with acidogenic bacteria. These bacteria reside inside a protective sheath which makes any curative treatment challenging. We propose an antibiotic-free strategy to disrupt the biofilm by engineered clustered carbon dot nanoparticles that function in the acidic environment of the biofilms. In vitro and ex vivo studies on the mature biofilms of Streptococcus mutans revealed >90% biofilm inhibition associated with the contact-mediated interaction of nanoparticles with the bacterial membrane, excessive reactive oxygen species generation, and DNA fragmentation. An in vivo examination showed that these nanoparticles could effectively suppress the growth of S. mutans. Importantly, 16S rRNA analysis of the dental microbiota showed that the diversity and richness of bacterial species did not substantially change with nanoparticle treatment. Overall, this study presents a safe and effective approach to decrease the dental biofilm formation without disrupting the ecological balance of the oral cavity.


Assuntos
Biofilmes/efeitos dos fármacos , Microbiota/fisiologia , Nanopartículas/toxicidade , Polímeros/toxicidade , Streptococcus mutans/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Feminino , Humanos , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Microbiota/genética , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Células NIH 3T3 , Nanopartículas/química , Nanopartículas/ultraestrutura , Polímeros/química , RNA Ribossômico 16S/genética , Ratos Sprague-Dawley , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/ultraestrutura
4.
PLoS One ; 16(5): e0251534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33970960

RESUMO

Melicope glabra (Blume) T. G. Hartley from the Rutaceae family is one of the richest sources of plant secondary metabolites, including coumarins and flavanoids. This study investigates the free radical scavenging and antibacterial activities of M. glabra and its isolated compounds. M. glabra ethyl acetate and methanol extracts were prepared using the cold maceration technique. The isolation of compounds was performed with column chromatography. The free radical scavenging activity of the extracts and isolated compounds were evaluated based on their oxygen radical absorbance capacity (ORAC) activities. The extracts and compounds were also subjected to antibacterial evaluation using bio-autographic and minimal inhibitory concentration (MIC) techniques against two oral pathogens, Enterococcus faecalis and Streptococcus mutans. Isolation of phytoconstituents from ethyl acetate extract successfully yielded quercetin 3, 5, 3'-trimethyl ether (1) and kumatakenin (2), while the isolation of the methanol extract resulted in scoparone (3), 6, 7, 8-trimethoxycoumarin (4), marmesin (5), glabranin (6), umbelliferone (7), scopoletin (8), and sesamin (9). The study is the first to isolate compound (1) from Rutaceae plants, and also the first to report the isolation of compounds (2-5) from M. glabra. The ORAC evaluation showed that the methanol extract is stronger than the ethyl acetate extract, while umbelliferone (7) exhibited the highest ORAC value of 24 965 µmolTE/g followed by glabranin (6), sesamin (9) and scopoletin (8). Ethyl acetate extract showed stronger antibacterial activity towards E. faecalis and S. mutans than the methanol extract with MIC values of 4166.7 ± 1443.4 µg/ml and 8303.3 ± 360.8 µg/ml respectively. Ethyl acetate extract inhibited E. faecalis growth, as shown by the lowest optical density value of 0.046 at a concentration of 5.0 mg/mL with a percentage inhibition of 95%. Among the isolated compounds tested, umbelliferone (7) and sesamin (9) exhibited promising antibacterial activity against S. mutans with both exhibiting MIC values of 208.3 ± 90.6 µg/ml. Findings from this study suggests M. glabra as a natural source of potent antioxidant and antibacterial agents.


Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis/crescimento & desenvolvimento , Sequestradores de Radicais Livres/farmacologia , Casca de Planta/química , Extratos Vegetais/química , Rutaceae/química , Streptococcus mutans/crescimento & desenvolvimento , Antibacterianos/química , Sequestradores de Radicais Livres/química
5.
Nat Chem Biol ; 17(5): 576-584, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33664521

RESUMO

Cariogenic Streptococcus mutans is known as a predominant etiological agent of dental caries due to its exceptional capacity to form biofilms. From strains of S. mutans isolated from dental plaque, we discovered, in the present study, a polyketide/nonribosomal peptide biosynthetic gene cluster, muf, which directly correlates with a strong biofilm-forming capability. We then identified the muf-associated bioactive product, mutanofactin-697, which contains a new molecular scaffold, along with its biosynthetic logic. Further mode-of-action studies revealed that mutanofactin-697 binds to S. mutans cells and also extracellular DNA, increases bacterial hydrophobicity, and promotes bacterial adhesion and subsequent biofilm formation. Our findings provided an example of a microbial secondary metabolite promoting biofilm formation via a physicochemical approach, highlighting the importance of secondary metabolism in mediating critical processes related to the development of dental caries.


Assuntos
Biofilmes/efeitos dos fármacos , Fatores Biológicos/biossíntese , Genes Bacterianos , Metabolismo Secundário/genética , Streptococcus mutans/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Fatores Biológicos/isolamento & purificação , Fatores Biológicos/farmacologia , Biologia Computacional/métodos , DNA/genética , DNA/metabolismo , Cárie Dentária/microbiologia , Cárie Dentária/patologia , Regulação Bacteriana da Expressão Gênica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Família Multigênica , Biossíntese de Peptídeos Independentes de Ácido Nucleico , Ligação Proteica , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/patogenicidade
6.
Molecules ; 26(4)2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33670043

RESUMO

The aim of this study was to investigate and understand bacterial adhesion to different dental material surfaces like amalgam, Chromasit, an Co-Cr alloy, an IPS InLine ceramic, yttrium stabilized tetragonal polycrystalline zirconia (TPZ), a resin-based composite, an Au-Pt alloy, and a tooth. For all materials, the surface roughness was assessed by profilometry, the surface hydrophobicity was determined by tensiometry, and the zeta potential was measured by electrokinetic phenomena. The arithmetic average roughness was the lowest for the TPZ ceramic (Ra = 0.23 µm ± 0.02 µm), while the highest value was observed for the Au-Pt alloy (Ra = 0.356 µm ± 0.075 µm). The hydrophobicity was the lowest on the TPZ ceramic and the highest on the Co-Cr alloy. All measured streaming potentials were negative. The most important cause of tooth caries is the bacterium Streptococcus mutans, which was chosen for this study. The bacterial adhesion to all material surfaces was determined by scanning electron microscopy. We showed that the lowest bacterial extent was on the amalgam, whereas the greatest extent was on tooth surfaces. In general, measurements showed that surface properties like roughness, hydrophobicity and charge have a significant influence on bacterial adhesion extent. Therefore, dental material development should focus on improving surface characteristics to reduce the risk of secondary caries.


Assuntos
Ligas/química , Cerâmica/química , Resinas Compostas/química , Amálgama Dentário/química , Metacrilatos/química , Streptococcus mutans/crescimento & desenvolvimento , Uretana/química , Aderência Bacteriana , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Propriedades de Superfície
7.
PLoS One ; 16(3): e0248308, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33667279

RESUMO

Periodontitis can result in tooth loss and the associated chronic inflammation can provoke several severe systemic health risks. Adjunctive to mechanical treatment of periodontitis and as alternatives to antibiotics, the use of probiotic bacteria was suggested. In this study, the inhibitory effect of the probiotic Streptococcus salivarius subsp. salivarius strains M18 and K12, Streptococcus oralis subsp. dentisani 7746, and Lactobacillus reuteri ATCC PTA 5289 on anaerobic periodontal bacteria and Aggregatibacter actinomycetemcomitans was tested. Rarely included in other studies, we also quantified the inverse effect of pathogens on probiotic growth. Probiotics and periodontal pathogens were co-incubated anaerobically in a mixture of autoclaved saliva and brain heart infusion broth. The resulting genome numbers of the pathogens and of the probiotics were measured by quantitative real-time PCR. Mixtures of the streptococcal probiotics were also used to determine their synergistic, additive, or antagonistic effects. The overall best inhibitor of the periodontal pathogens was L. reuteri ATCC PTA 5289, but the effect is coenzyme B12-, anaerobiosis-, as well as glycerol-dependent, and further modulated by L. reuteri strain DSM 17938. Notably, in absence of glycerol, the pathogen-inhibitory effect could even turn into a growth spurt. Among the streptococci tested, S. salivarius M18 had the most constant inhibitory potential against all pathogens, followed by K12 and S. dentisani 7746, with the latter still having significant inhibitory effects on P. intermedia and A. actinomycetemcomitans. Overall, mixtures of the streptococcal probiotics did inhibit the growth of the pathogens equally or-in the case of A. actinomycetemcomitans- better than the individual strains. P. gingivalis and F. nucleatum were best inhibited by pure cultures of S. salivarius K12 or S. salivarius M18, respectively. Testing inverse effects, the growth of S. salivarius M18 was enhanced when incubated with the periodontal pathogens minus/plus other probiotics. In contrast, S. oralis subsp. dentisani 7746 was not much influenced by the pathogens. Instead, it was significantly inhibited by the presence of other streptococcal probiotics. In conclusion, despite some natural limits such as persistence, the full potential for probiotic treatment is by far not utilized yet. Especially, further exploring concerted activity by combining synergistic strains, together with the application of oral prebiotics and essential supplements and conditions, is mandatory.


Assuntos
Anaerobiose/efeitos dos fármacos , Periodontite/tratamento farmacológico , Porphyromonas gingivalis/efeitos dos fármacos , Probióticos/farmacologia , Aggregatibacter actinomycetemcomitans/química , Aggregatibacter actinomycetemcomitans/crescimento & desenvolvimento , Antibiose/efeitos dos fármacos , Humanos , Lactobacillus reuteri/química , Lactobacillus reuteri/crescimento & desenvolvimento , Periodontite/microbiologia , Periodontite/patologia , Porphyromonas gingivalis/patogenicidade , Probióticos/química , Saliva/efeitos dos fármacos , Saliva/microbiologia , Streptococcus/química , Streptococcus/crescimento & desenvolvimento , Streptococcus mutans/química , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus salivarius/química , Streptococcus salivarius/crescimento & desenvolvimento
8.
mBio ; 12(2)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33688011

RESUMO

"METH mouth" is a common consequence of chronic methamphetamine (METH) use, resulting in tooth decay and painful oral tissue inflammation that can progress to complete tooth loss. METH reduces the amount of saliva in the mouth, promoting bacterial growth, tooth decay, and oral tissue damage. This oral condition is worsened by METH users' compulsive behavior, including high rates of consumption of sugary drinks, recurrent tooth grinding, and a lack of frequent oral hygiene. Streptococcus mutans is a Gram-positive bacterium found in the oral cavity and associated with caries in humans. Hence, we developed a murine model of METH administration, sugar intake, and S. mutans infection to mimic METH mouth in humans and to investigate the impact of this drug on tooth colonization. We demonstrated that the combination of METH and sucrose stimulates S. mutans tooth adhesion, growth, and biofilm formation in vivo METH and sucrose increased the expression of S. mutans glycosyltransferases and lactic acid production. Moreover, METH contributes to the low environmental pH and S. mutans sucrose metabolism, providing a plausible mechanism for bacterium-mediated tooth decay. Daily oral rinse treatment with chlorhexidine significantly reduces tooth colonization in METH- and sucrose-treated mice. Furthermore, human saliva inhibits S. mutans colonization and biofilm formation after exposure to either sucrose or the combination of METH and sucrose. These findings suggest that METH might increase the risk of microbial dental disease in users, information that may help in the development of effective public health strategies to deal with this scourge in our society.IMPORTANCE "METH mouth" is characterized by severe tooth decay and gum disease, which often causes teeth to break or fall out. METH users are also prone to colonization by cariogenic bacteria such as Streptococcus mutans In addition, this oral condition is aggravated by METH users' compulsive behavior, including the consumption of beverages with high sugar content, recurrent tooth grinding, and a lack of frequent oral hygiene. We investigated the effects of METH and sugar consumption on S. mutans biofilm formation and tooth colonization. Using a murine model of METH administration, sucrose ingestion, and oral infection, we found that the combination of METH and sucrose increases S. mutans adhesion and biofilm formation on the teeth of C57BL/6 mice. However, daily chlorhexidine-based oral rinse treatment reduces S. mutans tooth colonization. Similarly, METH has been associated with dry mouth or hyposalivation in users. Hence, we assessed the impact of human saliva on biofilm formation and demonstrated that surface preconditioning with saliva substantially reduces S. mutans biofilm formation. Our results are significant because to our knowledge, this is the first basic science study focused on elucidating the fundamentals of METH mouth using a rodent model of prolonged drug injection and S. mutans oral infection. Our findings may have important translational implications for the development of treatments for the management of METH mouth and more effective preventive public health strategies that can be applied to provide effective dental care for METH users in prisons, drug treatment centers, and health clinics.


Assuntos
Açúcares da Dieta/administração & dosagem , Metanfetamina/farmacologia , Boca/efeitos dos fármacos , Boca/patologia , Streptococcus mutans/metabolismo , Animais , Aderência Bacteriana/efeitos dos fármacos , Biofilmes , Cárie Dentária , Modelos Animais de Doenças , Feminino , Infecções por Bactérias Gram-Positivas/microbiologia , Masculino , Metanfetamina/administração & dosagem , Camundongos , Camundongos Endogâmicos C57BL , Boca/microbiologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Dente/efeitos dos fármacos , Dente/microbiologia
9.
PLoS Pathog ; 17(2): e1009289, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33577624

RESUMO

Bacterial extracellular DNA (eDNA) and activated platelets have been found to contribute to biofilm formation by Streptococcus mutans on injured heart valves to induce infective endocarditis (IE), yet the bacterial component directly responsible for biofilm formation or platelet adhesion remains unclear. Using in vivo survival assays coupled with microarray analysis, the present study identified a LiaR-regulated PspC domain-containing protein (PCP) in S. mutans that mediates bacterial biofilm formation in vivo. Reverse transcriptase- and chromatin immunoprecipitation-polymerase chain reaction assays confirmed the regulation of pcp by LiaR, while PCP is well-preserved among streptococcal pathogens. Deficiency of pcp reduced in vitro and in vivo biofilm formation and released the eDNA inside bacteria floe along with reduced bacterial platelet adhesion capacity in a fibrinogen-dependent manner. Therefore, LiaR-regulated PCP alone could determine release of bacterial eDNA and binding to platelets, thus contributing to biofilm formation in S. mutans-induced IE.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , DNA Bacteriano/metabolismo , Endocardite/microbiologia , Adesividade Plaquetária , Infecções Estreptocócicas/microbiologia , Streptococcus mutans/crescimento & desenvolvimento , Animais , Proteínas de Bactérias/genética , Endocardite/metabolismo , Endocardite/patologia , Espaço Extracelular/metabolismo , Voluntários Saudáveis , Interações Hospedeiro-Patógeno , Humanos , Ratos , Infecções Estreptocócicas/metabolismo , Infecções Estreptocócicas/patologia , Streptococcus mutans/genética
10.
PLoS One ; 16(2): e0247044, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33577600

RESUMO

OBJECTIVE: To evaluate the effect of medical cannabis consumption on oral flora and saliva. DESIGN: A clinical prospective study, at the rheumatology clinic of the Nazareth Hospital in Nazareth, recruiting consecutively patients approved for medical cannabis, evaluating their saliva flow, pH and microbial load of Streptococcus mutans and Lactobacillus, prior to and under medical cannabis treatment. METHODS: Patients recently licensed for medical cannabis treatment, were recruited just prior to starting medical cannabis consumption (week 0), 1 and 4 weeks later, patients provided 5-minute time saliva samples, which were measured for their volume and pH, and cultured on a special microbial kit, evaluating the growth of Streptococcus mutans and Lactobacillus. RESULTS: Out of 16 patients enrolled, 14 were female and had fibromyalgia. The mean age of the patients was 52.8±12.9 years. The mean saliva flow at week 0, week 1 and week 4 were 5.38±3.36 ml/5-minutes, 6 (p = 0.769) and 5.45 (p = 0.391), respectively, and for saliva pH were 6.28, 5.94 (p = 0.51) and 5.5 (p = 0.07) respectively also. The mean Streptococcus mutans growth score at weeks 0, 1 and 4 was1.8±0.75, 1.6±0.83 (p = 0.234), and 2.4±0.84 (p = 0.058), respectively. The mean Lactobacilli growth score at weeks 0, 1 and 4 was 2.59±0.88, 3.1±0.69 (p = 0.033) and 3.3±0.67 (p = 0.025), respectively. CONCLUSIONS: The results of this study show that medical cannabis consumption has no significant effect on saliva volume or pH, but it may be associated with changes in salivary levels of oral microbes such as Streptococcus mutans and Lactobacilli.


Assuntos
Lactobacillus/efeitos dos fármacos , Maconha Medicinal/farmacologia , Saliva/efeitos dos fármacos , Saliva/microbiologia , Streptococcus mutans/efeitos dos fármacos , Adulto , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Saliva/química , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/isolamento & purificação
11.
Med. oral patol. oral cir. bucal (Internet) ; 26(1): e1-e7, ene. 2021. tab, ilus, graf
Artigo em Inglês | IBECS | ID: ibc-200531

RESUMO

BACKGROUND: Oral microorganisms produce damage through the transfer to bloodstream, colonizing other tissues or direct damage in the oral cavity. Aim to study the quantitative interactions between C. albicans and the mutans streptococci and ms serotypes in the saliva of the oral cavity of patients with Down syndrome (DS). MATERIAL AND METHODS: Included 120 patients of both genders, 60 patients with Down syndrome (DS) and 60 patients as a control group (CG). Samples of saliva were taken, and bacteria and fungi were grown on TYCSB and Saboureaud agar. Microbiological, serological and quantitative analyses were performed to determine the kind of isolated of microorganisms corresponding to the ms c, e, f and k for species S. mutans and d and g for S. sobrinus and C. albicans. Electronic scanning microscopy was employed to visualize and confirm the colonies under study. Statistics analysis included t-test proofs for matched data test, Scheffé and ANOVA. RESULTS: Forming units (CFU) per mL of saliva of C. albicans a significant difference was observed among DS < CG groups. A correlation of the C. albicans quantity and the ms count was found by age intervals however, tendencies were different in SD and CG. Also, the CFU of C. albicans was different among the serotypes of ms (c, e, f, k < d, g, h, < notyped). CONCLUSIONS: These results show a significant non-random association between these two commensal microorganisms in different patient groups


No disponible


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Saliva/microbiologia , Boca/microbiologia , Candida albicans/crescimento & desenvolvimento , Streptococcus mutans/crescimento & desenvolvimento , Síndrome de Down/microbiologia , Streptococcus mutans/isolamento & purificação , Candida albicans/isolamento & purificação , Microscopia Eletrônica de Varredura , Contagem de Colônia Microbiana , Estudos de Casos e Controles , Sorogrupo
12.
J Enzyme Inhib Med Chem ; 36(1): 295-306, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33404277

RESUMO

Five series of novel carbazole derivatives containing an aminoguanidine, dihydrotriazine, thiosemicarbazide, semicarbazide or isonicotinic moiety were designed, synthesised and evaluated for their antimicrobial activities. Most of the compounds exhibited potent inhibitory activities towards different bacterial strains (including one multidrug-resistant clinical isolate) and one fungal strain with minimum inhibitory concentrations (MICs) between 0.5 and 16 µg/ml. Compounds 8f and 9d showed the most potent inhibitory activities (MICs of 0.5-2 µg/ml). Furthermore, compounds 8b, 8d, 8f, 8k, 9b and 9e with antimicrobial activities were not cytotoxic to human gastric cancer cell lines (SGC-7901 and AGS) or a normal human liver cell line (L-02). Structure-activity relationship analyses and docking studies implicated the dihydrotriazine group in increasing the antimicrobial potency and reducing the toxicity of the carbazole compounds. In vitro enzyme activity assays suggested that compound 8f binding to dihydrofolate reductase might account for the antimicrobial effect.


Assuntos
Anti-Infecciosos/síntese química , Proteínas de Bactérias/química , Carbazóis/síntese química , Inibidores Enzimáticos/síntese química , Escherichia coli/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/química , Anti-Infecciosos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Candida albicans/efeitos dos fármacos , Candida albicans/enzimologia , Candida albicans/crescimento & desenvolvimento , Carbazóis/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/crescimento & desenvolvimento , Guanidinas/química , Hepatócitos/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Ácidos Isonicotínicos/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/enzimologia , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Semicarbazidas/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologia , Staphylococcus aureus/crescimento & desenvolvimento , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/enzimologia , Streptococcus mutans/crescimento & desenvolvimento , Relação Estrutura-Atividade , Tetra-Hidrofolato Desidrogenase/metabolismo , Triazinas/química
13.
Int J Biol Macromol ; 173: 99-108, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33460660

RESUMO

The present investigation reports an in-vitro study using combination of laccase and an enhancer capable of inhibiting the growth of pathogenic microorganisms, preventing biofilm formation, and whitening teeth. Laccase-cinnamic acid system remarkably inhibited the growth of Aggregatibacter actinomycetemcomitans, Candida albicans, S. aureus, and Streptococcus mutans whilst showed no significant effects on Gram-negative bacteria. Data presented that cinnamic acid (10 mM) with laccase (0.125 U ml-1) led to a maximum decrease of about 90%, in S. mutans biofilm formation. The confocal laser scanning microscopy showed considerable detachment of S. mutans cells from glass substratum. The combined laccase-cinnamic acid system could remove teeth discoloration caused by coffee. SEM of the teeth surface exhibited no damages such as surface cracking or fracture. Liquid chromatography-tandem mass spectrometry (LC-MS) and cyclic voltammetry (CV) studies showed that laccase can catalyze the one-electron oxidation of cinnamic acid to the respective radical. This radical can then undergo several fates, including recombination with another radical to form a dimeric species, dismutation of the radical back to cinnamic acid or decarboxylation to give various reduced oxygen species. Therefore, the redox potential values of phenolic monomers/oligomers are related with their biological activities.


Assuntos
Aggregatibacter actinomycetemcomitans/efeitos dos fármacos , Antibacterianos/farmacologia , Cinamatos/farmacologia , Proteínas Fúngicas/farmacologia , Hericium/química , Lacase/farmacologia , Aggregatibacter actinomycetemcomitans/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Ácidos Cafeicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Catecóis/farmacologia , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Proteínas Fúngicas/isolamento & purificação , Ácido Gálico/farmacologia , Hericium/enzimologia , Hidroquinonas/farmacologia , Lacase/isolamento & purificação , Lactobacillus/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Oxirredução , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Clareadores Dentários/farmacologia
14.
FEMS Microbiol Lett ; 368(3)2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33452880

RESUMO

Streptococcus mutans, the etiologic agent of dental caries in humans, is considered a dominating force in the oral microbiome due to its highly-evolved propensity for survival. The oral pathogen encodes an elaborate array of regulatory elements, including the carbon catabolite-responsive regulator, CcpA, a global regulator key in the control of sugar metabolism and in stress tolerance response mechanisms. The recently characterized trehalose utilization operon, integral for the catabolism of the disaccharide trehalose, is controlled by a local regulator, TreR, which has been implicated in a number of cellular functions outside of trehalose catabolism. Electrophoretic mobility shift assays demonstrated that CcpA bound a putative cre site in the treR promoter. Loss of ccpA resulted in elevated expression of treR in cultures of the organism grown in glucose or trehalose, indicating that CcpA not only acts as a repressor of trehalose catabolism genes, but also the local regulator. The loss of both CcpA and TreR in S. mutans resulted in an impaired growth rate and fitness response, supporting the hypothesis that these regulators are involved in carbon catabolism control and in induction of components of the organism's stress response.


Assuntos
Proteínas de Bactérias/genética , Proteínas Repressoras/genética , Streptococcus mutans/genética , Streptococcus mutans/metabolismo , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Streptococcus mutans/crescimento & desenvolvimento
15.
J Gen Appl Microbiol ; 66(6): 330-338, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33012773

RESUMO

Aureobasidium pullulans YTP6-14 was demonstrated to be an excellent multiple biosurfactant producer utilizing cheap carbon sources available in Thailand, including glycerol and cassava flour hydrolysate. A. pullulans YTP6-14 maximally produced 1.81 g/l biosurfactant in an aqueous layer (BS-AQ) in a medium containing glycerol, and 7.37 or 6.37 g/l biosurfactant in a heavy oil layer (BS-HO) in cassava flour hydrolysate or a glucose containing medium, respectively. Each BS-AQ and BS-HO had critical micelle concentration values of 41.32 mg/l and 13.51 mg/l, and both biosurfactants formed a stable food oil emulsion and reduced the amount of biofilms formed by Streptococcus sobrinus and Streptococcus mutans. BS-AQ and BS-HO were mainly composed of liamocins or exophilins and massoia lactone, respectively.


Assuntos
Aureobasidium/metabolismo , Biofilmes/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus sobrinus/crescimento & desenvolvimento , Tensoativos/farmacologia , Antibacterianos/farmacologia , Aureobasidium/classificação , Biofilmes/crescimento & desenvolvimento , Óleos/química , Streptococcus mutans/efeitos dos fármacos , Streptococcus sobrinus/efeitos dos fármacos , Tensoativos/análise , Tensoativos/química
16.
J Appl Microbiol ; 130(2): 382-393, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32707601

RESUMO

AIMS: The aim of this study was to investigate the effects of trans-cinnamaldehyde (TC) and its synergistic activity with chlorhexidine (CHX) and fluoride against Streptococcus mutans. METHODS AND RESULTS: Streptococcus mutans UA159 was treated with TC alone and in combination with CHX or sodium fluoride. The synergy profile was analysed using the Zero Interaction Potency model. TC showed strong synergism (synergy score of 21·697) with CHX, but additive effect (synergy score of 5·298) with fluoride. TC and the combinations were tested for acid production (glycolytic pH drop) and biofilm formation by S. mutans, and nitric oxide production in macrophages. TC significantly inhibited sucrose-dependent biofilm formation and acid production by S. mutans. Mechanistic studies were carried out by qRT-PCR-based transcriptomic studies which showed that TC acts by impairing genes related to metabolism, quorum sensing, bacteriocin expression, stress tolerance and biofilm formation. CONCLUSIONS: trans-Cinnamaldehyde potentiates CHX and sodium fluoride in inhibiting S. mutans biofilms and virulence through multiple mechanisms. This study sheds significant new light on the potential to develop TC as an anti-caries treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: Oral diseases were classified as a 'silent epidemic' in the US Surgeon General's Report on Oral Health. Two decades later, >4 billion people are still affected worldwide by caries, having significant effects on the quality of life. There is an urgent need to develop novel compounds and strategies to combat dental caries. Here, we prove that TC downregulates multiple pathways and potentiates the CHX and fluoride to prevent S. mutans biofilms and virulence. This study sheds significant new light on the potential to develop TC in combination with CHX or fluoride as novel treatments to arrest dental caries.


Assuntos
Acroleína/análogos & derivados , Cariostáticos/farmacologia , Clorexidina/farmacologia , Fluoreto de Sódio/farmacologia , Streptococcus mutans/efeitos dos fármacos , Acroleína/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Sinergismo Farmacológico , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/metabolismo , Virulência/efeitos dos fármacos , Virulência/genética
17.
Int J Prosthodont ; 34(5): 626­634, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32588997

RESUMO

PURPOSE: To investigate and compare the degree of Streptococcus mutans (SM) colonization before and after in vitro wear simulation on monolithic zirconia (MZ), lithium disilicate (LD), ceramo-metal (CM), and composite resin (CR) specimens. MATERIALS AND METHODS: Sixteen circular discs (10 × 3 mm) were fabricated for each group (MZ, LD, CR, CM). Half of the samples from each group (n = 8) were subjected to a wear cycle (n = 32 in total). The wild-type SM bacteria was incubated, diluted, and cultured for growth on the specimens with polished (n = 32) and worn surfaces (n = 32). The number of bacteria was calculated from colony-forming units (CFU). ANOVA followed by Tukey honest significant difference test (α < .05) was used for statistics. RESULTS: SM adhesion on the polished surfaces of all the tested materials exhibited similar values (P = .215), with the number of SM being lowest for LD (21.87 ± 28.14) and highest for CM (90.62 ± 76.69). After the wear cycle, ANOVA indicated significant differences (P = .000) for the number of bacteria between pre- and postwear conditions of all groups. MZ (21,028 ± 1,507.98) and CM (13,025 ± 2,690.85) showed the highest and lowest numbers of SM colonies, respectively. According to t test, postwear SM adhesion to all materials (P = .000) was significantly higher. SM colonization on the worn surfaces of all the materials showed significant differences (P < .05), except for between LD and CR (P = .973). CONCLUSION: Polished surfaces of evaluated materials showed similar SM colonization, which emphasizes the importance of following the minimum requirements of the polishing/glazing procedures. SM colonization on the material surfaces significantly increased after wear. MZ and CM possessed the highest and lowest SM colonizations, respectively.


Assuntos
Streptococcus mutans , Aderência Bacteriana , Streptococcus mutans/crescimento & desenvolvimento , Propriedades de Superfície
18.
Rev. cuba. invest. bioméd ; 39(4): e687, oct.-dic. 2020. tab, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1156457

RESUMO

Objetivo: Determinar las propiedades antimicrobianas de la incorporación de nanopartículas de óxido de zinc y cobre en un adhesivo de grabado y lavado total sobre Streptococcus mutans en pacientes con restauraciones de resina compuesta confeccionadas con adhesivo cargado. Métodos: Este estudio clínico randomizado, participaron 25 pacientes, de ambos sexos, pertenecientes al posgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Chile, en los cuales se confirmó presencia de Streptococcus mutans en saliva. Se confeccionaron restauraciones de resina compuesta oclusales, en premolares superiores con indicación de exodoncia por el tratamiento de ortodoncia, con adhesivo cargado (cuya composición es 5 / 0.2 por ciento ZnO y Cu respectivamente) y control (sin presencia de nanopartículas en su composición), según el listado de aleatorización. Se tomaron muestras microbiológicas en tres tiempos con la Técnica de la cubeta (antes, 1 semana y 4 semanas posterior a la confección de las restauraciones). Se obtuvieron, aislaron e identificaron colonias de Streptococcus mutans a partir de las muestras obtenidas. Los datos fueron analizados por el test de Mann Whittney. Resultados: El promedio del recuento de UFC (unidades formadoras de colonias) de Streptococcus mutans en el grupo experimental fue mayor posterior a la confección de las restauraciones de resina compuesta.Los resultados de la identificación molecular por PCR demuestran la presencia de Streptococcus mutans en 20 de 25 muestras. Conclusiones: No existen diferencias en el recuento de Streptococcus mutans antes y después de la aplicación del adhesivo sobre las restauraciones de resina compuesta(AU)


Objective: Determine the antimicrobial properties of the incorporation of copper and zinc oxide nanoparticles into a total rinse and etch adhesive against Streptococcus mutans in patients with composite resin restorations made with loaded adhesive. Methods: A randomized clinical study was conducted of 25 patients of both sexes from the orthodontics graduate course taught at the Dental School of the University of Chile, in whom the presence of Streptococcus mutans was confirmed in saliva. Occlusal composite resin restorations were performed in upper premolars with exodontia indicated as part of the orthodontic treatment, using loaded adhesive (composition 5 / 0.2 percent ZnO and Cu, respectively) and control (without nanoparticles in its composition), according to the randomization list. Microbiological samples were taken at three moments applying the tray technique (before, 1 week after and 4 weeks after the restorations). Streptococcus mutans were obtained, isolated and identified from the samples taken. Data analysis was based on the Mann-Whitney test. Results: Mean Streptococcus mutans CFU count in the experimental group was higher after the composite resin restorations were made. Results of PCR molecular identification show the presence of Streptococcus mutans in 20 of 25 samples. Conclusions: No differences were found in the Streptococcus mutans count before and after application of the adhesive over the composite resin restorations(AU)


Assuntos
Humanos , Streptococcus mutans/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Cimentos Dentários/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Cirurgia Bucal/métodos , Epidemiologia Experimental
19.
Rev. cuba. invest. bioméd ; 39(4): e683, oct.-dic. 2020. tab, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1156456

RESUMO

Objetivo: Determinar las propiedades antimicrobianas de la incorporación de nanopartículas de óxido de zinc y cobre en un adhesivo de grabado y lavado total sobre Streptococcus mutans en pacientes con restauraciones de resina compuesta confeccionadas con adhesivo cargado. Métodos: Estudio experimental, randomizado, la muestra estuvo conformada por 25 pacientes, de ambos sexos, pertenecientes al posgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Chile, en los cuales se confirmó presencia de Streptococcus mutans en saliva. Se confeccionaron restauraciones de resina compuesta oclusales, en premolares superiores con indicación de exodoncia por el tratamiento de ortodoncia, con adhesivo cargado (cuya composición fue 5/0,2 por ciento ZnO y Cu, respectivamente) y control (sin presencia de nanopartículas en su composición), según el listado de aleatorización. Se tomaron muestras microbiológicas en tres tiempos con la técnica de la cubeta (antes, 1 semana y 4 semanas posterior a la confección de las restauraciones). Se obtuvieron, aislaron e identificaron colonias de Streptococcus mutans a partir de las muestras obtenidas. Se usó el test de Mann-Whitney mediante el paquete estadístico SPSS v.21 Resultados: El promedio del recuento de UFC de Streptococcus mutans en el grupo experimental fue mayor posterior a la confección de las restauraciones de resina compuesta. Los resultados de la identificación molecular por PCR demuestran la presencia de Streptococcus mutans en 20 de 25 muestras. Conclusiones: No existen diferencias en el recuento de Streptococcus mutans antes y después de la aplicación del adhesivo sobre las restauraciones de resina compuesta(AU)


Objective: To determine the antimicrobial properties of the incorporation of zinc and copper oxide nanoparticles in an etching and total wash adhesive on Streptococcus mutans in patients with composite resin restorations made with loaded adhesive. Methods: Experimental and randomized trial, the sample were 25 patients, of both sexes, belonging to the FOUCH Orthodontic postgraduate program, in whom the presence of Streptococcus mutans in saliva was confirmed. Occlusal composite resin restorations were made in upper premolars with indication of extraction by orthodontic treatment, with loaded adhesive (whose composition is 5 / 0.2% ZnO and Cu respectively) and control (without the presence of nanoparticles in their composition), according to the scrambling listing. Microbiological samples were taken in three stages with the cuvette technique (before, 1 week and 4 weeks after the restoration was made). Colonies of Streptococcus mutans were obtained, isolated and identified from the samples obtained. The statistical analysis used the SPSS v.21 software, the data was analyzed by Mann Whitney test Results: The average CFU count of Streptococcus mutans in the experimental group (adhesive modified with zinc oxide and copper nanoparticles) was higher after the fabrication of composite resin restorations. The results of molecular identification by PCR demonstrate the presence of Streptococcus mutans in 20 of 25 samples. Conclusions: There are no differences in the count of Streptococcus mutans before and after the application of the adhesive on the composite resin restorations(AU)


Assuntos
Humanos , Streptococcus mutans/crescimento & desenvolvimento , Contagem de Colônia Microbiana/métodos , Cimentos Dentários/uso terapêutico , Nanopartículas Metálicas/normas
20.
World J Microbiol Biotechnol ; 36(12): 189, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33242145

RESUMO

The purpose of this study was to develop a rapid and simple measurement method for biofilm formation inhibitory activity, and to screen food additives and foodstuffs that inhibit biofilm formation. The measurement method for biofilm formation inhibitory activity was developed by combining biofilm formation on pins of microtiter plate lids and staining using crystal violet. The optimum conditions for biofilm formation on the pins were established for seven Gram-positive and six Gram-negative bacteria by investigations of media, incubation time, and pin materials. Minimum concentrations of food additives required to inhibit biofilm formation were determined using the proposed method. The values obtained by the proposed and conventional methods agreed well. In addition, by sequential measurements of minimum inhibitory concentrations and minimum bactericidal concentrations using the proposed method, mechanisms of inhibition of biofilm formation were assessed. Furthermore, inhibitory activities of the water extracts of 498 different plant foodstuffs on biofilm formation by Streptococcus mutans were measured; five of the extracts showed potent inhibitory activities. The method proposed here circumvents the tedious and time-consuming conventional method in which biofilms are cultivated on the bottom of wells of microtiter plates.


Assuntos
Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Aditivos Alimentares/farmacologia , Testes de Sensibilidade Microbiana/métodos , Meios de Cultura , Coloração e Rotulagem/métodos , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento
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