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1.
J Appl Oral Sci ; 27: e20180262, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508789

RESUMO

The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. OBJECTIVE To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). METHODOLOGY TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). RESULTS Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.


Assuntos
Antibacterianos/química , Resinas Compostas/química , Metacrilatos/química , Triclosan/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Contagem de Colônia Microbiana , Resinas Compostas/farmacologia , Testes de Dureza , Teste de Materiais , Metacrilatos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Streptococcus mutans/efeitos dos fármacos , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Escovação Dentária , Triclosan/farmacologia
2.
J Appl Oral Sci ; 27: e20180593, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508792

RESUMO

There is growing evidence that C. albicans is associated with dental caries, but its role on caries development needs to be better clarified. Label="OBJECTIVE">To evaluate at the hard tissue level the effect of C. albicans on the cariogenic potential of S. mutans biofilms focusing on the mineral profile of induced carious lesions. This study also aimed to evaluate the effect of C. albicans on the acidogenic potential of S. mutans biofilms. METHODOLOGY Dual-species (CA+SM) and single-species biofilms (CA or SM) were grown on the surface of enamel slabs in the presence of glucose/sucrose supplemented culture medium for 24, 48 and 72 hours. Demineralization was evaluated through percentage of surface microhardness change (%SMC) and transversal microradiography analysis (ILM and LD) and pH of the spent medium was recorded daily. Data were analyzed by two-way ANOVA followed by Bonferroni correction. RESULTS%SMC was statistically different among the biofilms at each time point being the highest for SM biofilms and the lowest for CA biofilms which also differed from CA+SM biofilms [SM (24 h: 47.0±7.3; 48 h: 66.3±8.3; 72 h: 75.4±3.9); CA (24 h: 7.3±3.3; 48 h: 7.1±6.4; 72 h: 6.6±3.6); CA+SM (24 h: 35.9±7.39.1; 48 h: 47.2±9.5; 72 h: 47.6±9.5)]. pH of spent medium was statistically lower for SM biofilms compared to the other biofilms at each time point and remained constant over time while pH values increased from 24 to 72 h for both CA and CA+SM biofilms [SM (24 h: 4.4±0.1; 48 h: 4.4±0.1; 72 h: 4.5±0.1); CA (24 h: 6.9±0.3; 48 h: 7.2±0.2; 72 h: 7.5±0.2); CA+MS (24 h: 4.7±0.2; 48 h: 5.1±0.1; 72 h: 6.1±0.6)]. IML and LD for SM biofilms increased over time while no difference was observed from 24 to 72 h for the other biofilms. CONCLUSIONS The present data suggest that C. albicans has low enamel demineralization potential and the presence of C. albicans can reduce both the cariogenic and acidogenic potentials of S. mutans biofilms.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Esmalte Dentário/microbiologia , Streptococcus mutans/metabolismo , Desmineralização do Dente/microbiologia , Ácidos/metabolismo , Animais , Bovinos , Contagem de Colônia Microbiana , Esmalte Dentário/química , Testes de Dureza , Concentração de Íons de Hidrogênio , Microrradiografia/métodos , Valores de Referência , Propriedades de Superfície , Fatores de Tempo
3.
Shokuhin Eiseigaku Zasshi ; 60(4): 88-95, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31474656

RESUMO

Microbial colony counts of concern of food products are one of the most important items in microbiological examinations. The distributions of colony counts per agar plate of food samples are considered to be reflected with microbial cell distributions in food homogenates. However, (i) the probabilistic distributions of the colony counts per agar plate at the dilution of counting and (ii) the relationship between the colony counts per plate and the number of agar plates for food samples have not been intensively studied so far. In this study, therefore, these two points were studied with raw food samples of raw minced beef and chicken and raw milk and microbial culture samples of Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae. Among four major probabilistic distributions, it was found that aerobic plate counts per plate of the foods were well described with negative binomial, Poisson, and normal distributions and that the colony counts per plate of microbial cultures were described well with binomial, Poisson, and normal distributions. The effect of the number of agar plates on the estimation of the mean of colony counts per plate of a sample was then studied with the data randomly resampled from the experimental data. The resampled data showed that with more number of plates the mean of counts fluctuated less and the coefficients of variation of colony counts per plate decreased further, which were coincident to the estimated by the central limit theory. Our study would provide useful information on the characteristics of colony counts per plate of food samples which are routinely examined.


Assuntos
Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Ágar , Animais , Bovinos , Escherichia coli/isolamento & purificação , Carne/microbiologia , Leite/microbiologia , Saccharomyces cerevisiae/isolamento & purificação , Staphylococcus aureus/isolamento & purificação
4.
J Appl Oral Sci ; 27: e20180699, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411265

RESUMO

OBJECTIVE: This study investigated the role of extracellular deoxyribonucleic acid (eDNA) on Enterococcus faecalis ( E. faecalis ) biofilm and the susceptibility of E. faecalis to sodium hypochlorite (NaOCl). METHODOLOGY: E. faecalis biofilm was formed in bovine tooth specimens and the biofilm was cultured with or without deoxyribonuclease (DNase), an inhibitor of eDNA. Then, the role of eDNA in E. faecalis growth and biofilm formation was investigated using colony forming unit (CFUs) counting, eDNA level assay, crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy. The susceptibility of E. faecalis biofilm to low (0.5%) or high (5%) NaOCl concentrations was also analyzed by CFU counting. RESULTS: CFUs and biofilm formation decreased significantly with DNase treatment (p<0.05). The microstructure of DNase-treated biofilms exhibited less structured features when compared to the control. The volume of exopolysaccharides in the DNase-treated biofilm was significantly lower than that of control (p<0.05). Moreover, the CFUs, eDNA level, biofilm formation, and exopolysaccharides volume were lower when the biofilm was treated with DNase de novo when compared to when DNase was applied to matured biofilm (p<0.05). E. faecalis in the biofilm was more susceptible to NaOCl when it was cultured with DNase (p<0.05). Furthermore, 0.5% NaOCl combined with DNase treatment was as efficient as 5% NaOCl alone regarding susceptibility (p>0.05). CONCLUSIONS: Inhibition of eDNA leads to decrease of E. faecalis biofilm formation and increase of susceptibility of E. faecalis to NaOCl even at low concentrations. Therefore, our results suggest that inhibition of eDNA would be beneficial in facilitating the efficacy of NaOCl and reducing its concentration.


Assuntos
Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , DNA Bacteriano/farmacologia , Desoxirribonucleases/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Hipoclorito de Sódio/farmacologia , Animais , Bovinos , Contagem de Colônia Microbiana , Cavidade Pulpar/microbiologia , Testes de Sensibilidade Microbiana , Microscopia Confocal , Microscopia Eletrônica de Varredura , Polissacarídeos Bacterianos/isolamento & purificação , Reprodutibilidade dos Testes , Fatores de Tempo
5.
J Microbiol Biotechnol ; 29(8): 1240-1247, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31370118

RESUMO

This study was conducted to examine the inactivation effect of the combined treatment of high hydrostatic pressure (HHP; 400 MPa for 1, 3, and 5 min) and cationic surfactant washing (0.05% benzethonium chloride, BEC) against Listeria monocytogenes inoculated on fresh-cut broccoli (FCB). Washing with BEC at concentrations exceeding 0.05% resulted in 2.3 logreduction of L. monocytogenes counts on FCB, whereas HHP treatment had approximately 5.5- 5.6 log-reductions regardless of the treatment time. Scanning electron microscopy corroborated microbial enumeration, revealing that the combined treatment was more effective in removing L. monocytogenes from FCB than individual treatment with HHP or BEC. Color and total glucosinolate content were maintained after the combined treatment, although the hardness of the FCB slightly decreased. The results clearly suggest that the combined treatment of HHP and BEC washing has potential value as a new sanitization method to improve the microbial safety of FCB.


Assuntos
Brassica/microbiologia , Conservação de Alimentos/métodos , Listeria monocytogenes/efeitos dos fármacos , Tensoativos/farmacologia , Benzetônio/farmacologia , Contagem de Colônia Microbiana , Cor , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Qualidade dos Alimentos , Inocuidade dos Alimentos , Pressão Hidrostática , Listeria monocytogenes/crescimento & desenvolvimento
6.
Microbiol Res ; 228: 126305, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422234

RESUMO

Traditional culture-based enumeration methods were compared with the ethidium monoazide quantitative polymerase chain reaction (EMA-qPCR) technique to assess Bdellovibrio-and-like-organisms (BALOs) predator-prey interactions. Gram-negative [Pseudomonas spp. and Klebsiella pneumoniae (K. pneumoniae)] and Gram-positive [Staphylococcus aureus (S. aureus) and Enterococcus faecium (E. faecium)] organisms were employed as prey cells, while a Bdellovibrio bacteriovorus strain (PF13) was used as the predator. The co-culture experiments were also compared in diluted nutrient broth (DNB) and HEPES buffer. In both media, K. pneumoniae (maximum log reduction of 5.13) and Pseudomonas fluorescens (P. fluorescens) (maximum log reduction of 4.21) were sensitive to predation by B. bacteriovorus PF13 as their cell counts and gene copies were reduced during all the co-culture experiments, while the concentration of B. bacteriovorus PF13 increased. The concentration of B. bacteriovorus PF13 also increased in the presence of S. aureus (HEPES buffer) and E. faecium (DNB), indicating that the predator interacted with these Gram-positive prey in order to survive. Moreover, as no predator plaques were produced in the co-culture experiments with P. aeruginosa (DNB and HEPES buffer), S. aureus (DNB and HEPES buffer) and E. faecium (HEPES buffer), EMA-qPCR proved to be beneficial in monitoring the concentration of B. bacteriovorus. In conclusion, the cell counts and/or EMA-qPCR analysis for the HEPES buffer and DNB assays were successfully employed to monitor the predation of P. fluorescens and K. pneumoniae by B. bacteriovorus, while E. faecium was sensitive to predation in DNB and S. aureus was sensitive to predation in HEPES buffer.


Assuntos
Azidas , Fenômenos Fisiológicos Bacterianos , Interações Microbianas/fisiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Bactérias , Bdellovibrio bacteriovorus/fisiologia , Técnicas de Cocultura , Contagem de Colônia Microbiana , Enterococcus faecium/fisiologia , Klebsiella pneumoniae/fisiologia , Pseudomonas/fisiologia , Staphylococcus aureus/fisiologia , Águas Residuárias/microbiologia , Purificação da Água
7.
Am J Dent ; 32(4): 201-207, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31436941

RESUMO

PURPOSE: To evaluate in vitro the effectiveness of eight different cleansers containing alkaline peroxide against yeast [Candida albicans (Ca) and Candida glabrata (Cg) ], Gram-negative bacteria [Escherichia coli (Ec) and Pseudomonas aeruginosa (Pa) ], and Gram-positive bacteria [ Bacillus subtilis (Bs), Enterococcus faecalis (Ef), Staphylococcus aureus (Sa), and Streptococcus mutans (Sm) ]. METHODS: Denture base acrylic resin specimens (Lucitone 550; 1264 denture base acrylic resin specimens) were obtained from a circular metal matrix (15 x 3 mm) and sterilized with microwave irradiation (650 W, 6 minutes). The specimens were contaminated with 106 CFU/mL suspension of yeasts and 108 CFU/mL suspensions of Gram-positive and -negative bacteria. The contaminated specimens were incubated (37°C/48 hours) and immersed (short cycle) in a stainless steel basket placed in a beaker. The beaker contained one of the following cleanser solutions, which were prepared and used according to the manufacturers' instructions (n=10): PBS (positive control, C), Fixodent (FI), Medical Interporous (MI), Kukident (KU), Efferdent Plus (EF), Equate (EQ), Kroger (KR), Kirari (KI), and Corega Tabs (CT). Reduction in the viability of microorganisms was evaluated through counting of Colony Forming Units (CFU/mL), metabolic activity (XTT), and cell viability by epifluorescence microscopy (EM) analyses. For counting CFU, the specimens (n=10 of each group) were washed and immersed in Letheen medium, from which aliquots were obtained and seeded into selective solid culture media. After incubation (37°C, 24 hours), the colonies were counted (CFU/mL). The metabolic activity of microorganisms was measured using XTT reduction assay (n=5). For EM analysis, the specimens (n= 2 of each group) were stained (Live/Dead BacLight), and the images were analyzed in terms of biofilm areas (total and living cells). Data were processed and analyzed by Wilcoxon, Mann Whitney and Kruskal-Wallis tests followed by Dunn test (α= 0.05). RESULTS: Significant differences were found between the experimental groups and C for the evaluated microorganisms. MI was the most effective for yeasts; this cleanser reduced the metabolic activity, viability, and total counts of both yeasts evaluated. All cleansers reduced the total counts of Gram-negative microorganisms, except CT for Pa. For Gram-negative bacteria, KR, CT, EF, and EQ significantly reduced the metabolic activity of Ec but did not remove all dead cells. FI and MI significantly reduced the metabolic activity of Pa, and the latter also removed the dead cells of Pa. FI and MI showed improved results against all Gram-positive bacteria. Both cleansers significantly decreased the metabolic activity of all bacterial species and reduced the viability of Sa, Ef, and Bs. MI also reduced the biofilm aggregates of Sm. CLINICAL SIGNIFICANCE: This study concluded that under the experimental conditions tested, denture cleansers can be used as coadjutants in denture cleaning. The evaluated cleansers exhibited disinfectant action, thereby preventing the proliferation of microorganisms on the denture surface and reducing the risk of opportunistic infections.


Assuntos
Biofilmes , Bases de Dentadura , Higienizadores de Dentadura , Peróxidos , Biofilmes/efeitos dos fármacos , Contagem de Colônia Microbiana , Dentaduras , Peróxidos/farmacologia
8.
Rev Soc Bras Med Trop ; 52: e20190135, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390442

RESUMO

INTRODUCTION: Musca domestica is resistant to many insecticides; hence, biological control is a suitable alternative. METHODS: We evaluated the lethality of strain Btk176 towards the larval and adult M. domestica and the histopathological effects in the larvae midgut. RESULTS: We observed 99% larval and 78.9% adult mortality within 48 hours of spore ingestion (dosage, 2.4×108 CFU/ml). The histopathological effects were consistent with cytotoxicity. PCR analysis showed the presence of the cry1Ba gene. Transmission electron microscopy revealed a bipyramidal parasporal body. Thurigiensin activity was not detected. CONCLUSIONS: The serovar, Btk176 might be a potential biocontrol agent for houseflies.


Assuntos
Bacillus thuringiensis , Toxinas Bacterianas/farmacologia , Moscas Domésticas/efeitos dos fármacos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Análise de Variância , Animais , Contagem de Colônia Microbiana , Exotoxinas , Microscopia Eletrônica de Transmissão , Controle Biológico de Vetores/métodos , Reprodutibilidade dos Testes
9.
Int J Nanomedicine ; 14: 5943-5955, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31447553

RESUMO

Background and aim: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of surgical infection, and its resistance to numerous conventional antibiotics makes treatment difficult. Although vancomycin is often an effective agent for the initial therapy of MRSA, clinical failure sometimes occurs. Therefore, there is an urgent need to develop better therapies. Here, we prepared some vancomycin-loaded nanoliposomes coupled with anti-staphylococcal protein (lysostaphin) and evaluated their in vitro and in vivo efficacy as a topical MRSA therapy. Methods: Vancomycin was encapsulated in liposomes, and the coupling of lysostaphin with the surface of liposomes was carried out through cyanuric functional groups. The bactericidal efficacies and a full characterization were evaluated. To define different nanoliposomal-bacterium interactions and their bactericidal effect, flow cytometry was employed. Finally, in vivo, the topical antibacterial activity of each formulation was measured against surgical wound MRSA infection in a mouse model. Results: High encapsulation and conjugation efficiency were achieved for all formulations. All the formulations showed a significant reduction in bacterial counts (p<0.05). The targeted liposomes more effectively suppress bacterial infection in vitro and in vivo relative to equivalent doses of untargeted vancomycin liposome. The flow cytometry results confirmed liposome-bacterium interactions, which increased during the incubation time. The maximum binding rate and the bactericidal effect were significantly higher in targeted liposomes (p<0.05) compared with control liposomes. Conclusion: Our data suggest a novel nano-vehicle (lysostaphin-conjugated coupled liposomal vancomycin) which could be used as a great topical antimicrobial construct for treatment of MRSA skin infections.


Assuntos
Antibacterianos/uso terapêutico , Lisostafina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/microbiologia , Vancomicina/uso terapêutico , Idoso , Animais , Antibacterianos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Quimioterapia Combinada , Humanos , Lipossomos , Lisostafina/farmacologia , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Infecções Cutâneas Estafilocócicas/patologia , Vancomicina/farmacologia
10.
BMC Infect Dis ; 19(1): 575, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31269912

RESUMO

BACKGROUND: Hospital environment in patient care has been linked on healthcare-associated infections (HAI). No touch disinfection technologies that utilize pulsed xenon ultraviolet light has been recognized to prevent infection in contaminated environments. The purpose of this study was: 1) to evaluate the effectiveness of pulsed-xenon ultraviolet light (PX-UV) disinfection for the reduction of bacteria on environmental surfaces of Hospital General Enrique Garcés, and 2) to evaluate the in-vitro efficacy against multi-drug resistance microorganisms. METHODS: This was a quality-improvement study looking at cleaning and disinfection of patient areas. During the study, a total of 146 surfaces from 17 rooms were sampled in a secondary 329-bed public medical center. Microbiological samples of high-touch surfaces were taken after terminal manual cleaning and after pulsed xenon ultraviolet disinfection. Cleaning staff were blinded to the study purpose and told clean following their usual protocols. For positive cultures PCR identification for carbapenemase-resistance genes (blaKPC, blaIMP, blaVIM, and blaNDM) were analyzed and confirmed by sequencing. The total number of colony forming units (CFU) were obtained and statistical analyses were conducted using Wilcoxon Rank Sum tests to evaluate the difference in CFU between terminal manual cleaning and after pulsed xenon ultraviolet disinfection. RESULTS: After manual disinfection of 124 surfaces showed a total of 3569 CFU which dropped to 889 CFU in 80 surfaces after pulsed xenon disinfection (p < 0.001). Overall, the surface and environmental contamination was reduced by 75% after PX-UV compared to manual cleaning and disinfection. There were statistically significant decreases in CFU counts of high touch surfaces in OR 87% (p < 0.001) and patient rooms 76% (p < 0.001). Four rooms presented serine carbapenemases blaKPC, and metallo beta-lactamases blaNDM, blaVIM, blaIMP. confirmed by PCR and sequencing. The in-vitro testing with endemic strains found that after five minutes of pulsed xenon ultraviolet exposure an 8-log reduction was achieved in all cases. CONCLUSION: This study is one of the first of its kind in an Ecuador Hospital. We found that pulsed-xenon ultraviolet disinfection technology is an efficacious complement to the established manual cleaning protocols and guidelines in the significant reduction of MDRO.


Assuntos
Desinfecção/métodos , Hospitais , Bactérias/genética , Proteínas de Bactérias/genética , Contagem de Colônia Microbiana , Infecção Hospitalar/prevenção & controle , Desinfecção/instrumentação , Farmacorresistência Bacteriana/genética , Equador , Humanos , Quartos de Pacientes , Raios Ultravioleta , Xenônio , beta-Lactamases/genética
11.
Int J Nanomedicine ; 14: 4697-4708, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31303754

RESUMO

Introduction and aim: Chlorhexidine Hydrochloride [Chx.HCl] has a broad-spectrum antibacterial effect, sustained action and low toxicity so it has been recommended as a potential root canal irrigant. The aim of this study was to improve the penetration ability, cleansing and antibacterial effect of Chx.HCl using a newly formulated Chx.HCl nanoemulsion and use it as root canal irrigant. Methods: Chx.HCl nanoemulsions were prepared using two different oils; Oleic acid and Labrafil M1944CS, two surfactants; Tween 20 and Tween 80 and co-surfactant; Propylene Glycol. Pseudoternary phase diagrams were constructed to designate the optimum systems. The prepared nanoemulsion formulae were evaluated for their drug content, emulsification time, dispersibility, droplet size, in-vitro drug release, thermodynamic stability, In-vitro antibacterial activity and ex-vivo study for the selected formula. Comparisons were made of Chx.HCl nanoemulsion with two different concentrations 0.75% and 1.6% vs Chx.HCl normal particle size as root canal irrigant for their penetration ability, cleansing effect and antibacterial effect. Results: The selected formula was F6 with composition of 2% Labrafil, 12% Tween 80 and 6% Propylene glycol. It has small particle size (12.18 nm), short emulsification time (1.67 seconds), and fast dissolution rate after 2 minutes. It was found to be a thermodynamically/physically stable system. The higher concentration of Chx.HClnanoemulsion1.6% shows the best penetration ability compared to Chx.HCl normal particle size due to the smaller particle size. Chx.HCl nanoemulsion 1.6% has the lowest mean value of the remaining debris surface area (2001.47 µm2) when compared to normal particle size material (2609.56 µm2). Conclusion: Chx.HCl nanoemulsion preparation has better cleansing ability and antibacterial effect with high efficacy on Enterococcus faecalis, where high reduction rate or complete eradication of bacterial cells has been achieved.


Assuntos
Antibacterianos/farmacologia , Clorexidina/farmacologia , Emulsões/química , Nanopartículas/química , Irrigantes do Canal Radicular/farmacologia , Contagem de Colônia Microbiana , Composição de Medicamentos , Liberação Controlada de Fármacos , Enterococcus faecalis/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Transição de Fase , Termodinâmica
12.
Int J Nanomedicine ; 14: 4613-4624, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308651

RESUMO

Background: Bacterial infection is a common and serious complication in orthopedic implants following traumatic injury, which is often associated with extensive soft tissue damage and contaminated wounds. Multidrug-resistant bacteria have been found in these infected wounds, especially in patients who have multi trauma and prolonged stay in intensive care units.Purpose: The objective of this study was to develop a coating on orthopedic implants that is effective against drug-resistant bacteria. Methods and results: We applied nanoparticles (30-70nm) of the trace element selenium (Se) as a coating through surface-induced nucleation-deposition on titanium implants and investigated the antimicrobial activity against drug resistant bacteria including Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Staphylococcus epidermidis (MRSE) in vitro and in an infected femur model in rats.The nanoparticles were shown in vitro to have antimicrobial activity at concentrations as low as 0.5ppm. The nanoparticle coatings strongly inhibited biofilm formation on the implants and reduced the number of viable bacteria in the surrounding tissue following inoculation of implants with biofilm forming doses of bacteria. Conclusion: This study shows a proof of concept for a selenium nanoparticle coatings as a potential anti-infective barrier for orthopedic medical devices in the setting of contamination with multi-resistant bacteria. It also represents one of the few (if only) in vivo assessment of selenium nanoparticle coatings on reducing antibiotic-resistant orthopedic implant infections.


Assuntos
Anti-Infecciosos/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nanopartículas/química , Ortopedia , Próteses e Implantes , Selênio/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Animais , Biofilmes/efeitos dos fármacos , Placas Ósseas , Parafusos Ósseos , Células Cultivadas , Contagem de Colônia Microbiana , Humanos , Masculino , Nanopartículas/ultraestrutura , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Ratos Sprague-Dawley , Titânio/farmacologia
13.
Int J Food Microbiol ; 305: 108245, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31295678

RESUMO

This study aimed to evaluate the performance of Hicrome Bacillus™ agar for isolation and rapid identification of the aerobic spore-forming bacteria most frequently found in honey samples. A collection of 197 bacterial isolates of Bacillus, Brevibacillus, Lysinibacillus, Paenibacillus, and Rummeliibacillus belonging to different species that have been reported in honey were screened for their abilities to grow and for their colony colors and medium appearance in HiCrome Bacillus agar. Also, 21 strains from culture collections were used for comparison and quality controls. A flowchart utilizing a combination of colony and media characteristics in the chromogenic medium and a set of simple biochemical and morphological tests were elaborated for quick presumptive identification. A procedure for direct isolation from honey samples was developed. In conclusion, HiCrome Bacillus agar in combination with simple microbiological tests was highly useful for rapid and reliable identification of most Bacillus, Brevibacillus, Lysinibacillus and Paenibacillus species commonly found in honey samples facilitating isolation from polymicrobial honey.


Assuntos
Bacillaceae/isolamento & purificação , Bacillus/isolamento & purificação , Contagem de Colônia Microbiana/métodos , Mel/microbiologia , Bacillaceae/classificação , Bacillaceae/genética , Bacillaceae/crescimento & desenvolvimento , Bacillus/classificação , Bacillus/genética , Bacillus/crescimento & desenvolvimento , Contagem de Colônia Microbiana/instrumentação , Microbiologia de Alimentos
14.
J Med Microbiol ; 68(9): 1353-1358, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31271350

RESUMO

Introduction. Candida auris is a pathogenic yeast that mainly affects immunosuppressed patients and those with implanted medical devices. This pathogen also displays elevated resistance to common antifungals and high survival and spreading capacities. Since no antifungal breakpoints have yet been defined for this pathogen, the data obtained here can be useful for further research concerning treatment or implementation of a prevention and disinfection protocol. Our aim was to study the antifungal resistance of C. auris to current antifungals in planktonic and sessile states. Using confocal laser scanning microscopy and viable biomass production, we demonstrated the ability of C. auris to develop a mature biofilm. We compared the minimal inhibitory concentration (MIC) and the minimal biofilm eradication concentration (MBEC) for the C. auris DSM 21092 strain plus two clinical isolates, and the results were compared with those obtained for Candida albicans and Candida parapsilosis, two species strongly linked to bloodstream infections and infections associated with biomaterials. We found that the clinical isolates of C. auris were resistant to fluconazole and sensitive to echinocandins and polyenes. The C. auris biofilms did not show susceptibility to any antifungal agent, showing MBECs that were up to 512-fold higher than the MICs. These findings highlight the importance of biofilm formation as a key factor underlying the resistance of this species to antifungals and suggest that the presence of implantable medical devices is one of the major risk factors in immunocompromised patients.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida parapsilosis/efeitos dos fármacos , Candidíase/microbiologia , Contagem de Colônia Microbiana , Farmacorresistência Fúngica , Equinocandinas/farmacologia , Fluconazol/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Microscopia Confocal , Polienos/farmacologia
15.
BMC Infect Dis ; 19(1): 646, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324234

RESUMO

BACKGROUND: The aim of this study was to establish a set of assessment methods suitable for evaluating the complex indoor environment of hospital wards and to ascertain the composition of bacteria and microbial ecology of hospital wards. METHODS: Colony-forming units (CFUs), PM2.5 detection, real-time PCR, and adenosine triphosphate (ATP) bioluminescence assay were employed to evaluate the complexity of indoor air in 18 wards of nine departments in a hospital and two student dormitories in a university. Subsequently, the microbial samples were quantified and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: Although the studied indices were relatively independent, the PM2.5 content was correlated with bacterial CFUs determined by passive sedimentation method, bacterial and fungal counts measured by real-time PCR, and ATP bioluminescence assay. The composition of microorganisms in the air of hospital wards differed from that in the air of student dormitories. The dominant genera in hospital wards were Staphylococcus (39.4%), Micrococcus (21.9%), Corynebacterium (11.7%), Kocuria (4.4%), Bacillus (2.9%), Streptococcus (1.6%), Moraxella (1.6%), and Enterococcus (1.3%), and the microbial ecology differed between Respiration Dept. III and other hospital departments. Additionally, 11.1 and 27.3% of bacteria in hospital wards and student dormitories were not identified, respectively. CONCLUSIONS: Assessment of environmental quality of hospital wards should be based on comprehensive analysis with multiple indicators. There may be imbalances in the microbial diversity in the hospital wards, therefore, monitoring of the environmental quality of hospitals is important in the prevention of nosocomial infections.


Assuntos
Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Hospitais , Medições Luminescentes/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Trifosfato de Adenosina/análise , Carga Bacteriana/métodos , China , Contagem de Colônia Microbiana/métodos , Humanos , Material Particulado/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Staphylococcus
16.
Food Chem ; 295: 361-367, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174770

RESUMO

This study was conducted to investigate the effects of Lactobacillus plantarum NJAU-01 isolated from Chinese dry-cured ham (Jinhua ham) on the regulation of protein oxidation of fermented sausages. Fermented sausages were prepared with different concentrations of L. plantarum NJAU-01 (105 CFU/g, 107 CFU/g and 109 CFU/g), and the commercial strain was used as positive control. The results showed that L. plantarum NJAU-01 at 107 CFU/g and 109 CFU/g significantly lowered the protein carbonyl content and protein surface hydrophobicity compared with the control (P < 0.05). The total sulfhydryl contents in L. plantarum NJAU-01 groups were significantly higher than that of the group without starter culture (P < 0.05). Significant changes were found in sarcoplasmic protein bands within 130-250 kDa, 100-130 kDa and 25-35 kDa during sausage fermentation (P < 0.05). Our data suggest that L. plantarum NJAU-01 has the potential to be an antioxidant starter culture in fermented sausages.


Assuntos
Alimentos Fermentados/microbiologia , Lactobacillus plantarum/fisiologia , Produtos da Carne/microbiologia , Proteínas de Carne/metabolismo , Animais , Antioxidantes/metabolismo , Contagem de Colônia Microbiana , Fermentação , Microbiologia de Alimentos , Lactobacillus plantarum/isolamento & purificação , Oxirredução , Carbonilação Proteica , Carne Vermelha/microbiologia , Suínos
17.
Pol J Microbiol ; 68(2): 211-216, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250591

RESUMO

Rhizoctonia solani is a soil-borne fungus causing a wide range of plants diseases. Trichoderma gamsii strain T30 has previously been reported as antagonistic against R. solani. Although there are a few studies about the influence of Trichoderma strains on the R. solani density in a pathosystem in the presence of plant hosts, this report for the first time comprehensively describes in situ effects of a T. gamsii strain on the population density of R. solani in the soil microcosmic conditions. The population dynamics of R. solani were followed in the autoclaved and non-autoclaved soils in artificially prepared microcosms up to day 25 after co-inoculation with T. gamsii in the variable ratios (R1/T1; R1/T0.1; R1/T0.01 of R. solani/T. gamsii). The population density of R. solani was evaluated by qPCR. In the autoclaved soil, target DNA copies of R. solani increased in the control samples from 1 × 105 to 6.5 × 106. At R1/T0.01, the number of target DNA copies were not significantly changed until day 11; however, it decreased by around five times at day 25. At R1/T0.1 and R1/T1, the number of DNA copies was reduced to 2.1 × 106 and 7.6 × 105 at day 11, respectively and the reduction was as much as 17 times at day 25. In the non-autoclaved soil, the number of the fungal cells decreased at day 25 whether inoculated or not with Trichoderma indicating a general suppression by the soil microbiome. In brief, T. gamsii significantly inhibited the growth of R. solani in the soil in situ and there was a general suppressive effect of the natural microbiome.Rhizoctonia solani is a soil-borne fungus causing a wide range of plants diseases. Trichoderma gamsii strain T30 has previously been reported as antagonistic against R. solani. Although there are a few studies about the influence of Trichoderma strains on the R. solani density in a pathosystem in the presence of plant hosts, this report for the first time comprehensively describes in situ effects of a T. gamsii strain on the population density of R. solani in the soil microcosmic conditions. The population dynamics of R. solani were followed in the autoclaved and non-autoclaved soils in artificially prepared microcosms up to day 25 after co-inoculation with T. gamsii in the variable ratios (R1/T1; R1/T0.1; R1/T0.01 of R. solani/T. gamsii). The population density of R. solani was evaluated by qPCR. In the autoclaved soil, target DNA copies of R. solani increased in the control samples from 1 × 105 to 6.5 × 106. At R1/T0.01, the number of target DNA copies were not significantly changed until day 11; however, it decreased by around five times at day 25. At R1/T0.1 and R1/T1, the number of DNA copies was reduced to 2.1 × 106 and 7.6 × 105 at day 11, respectively and the reduction was as much as 17 times at day 25. In the non-autoclaved soil, the number of the fungal cells decreased at day 25 whether inoculated or not with Trichoderma indicating a general suppression by the soil microbiome. In brief, T. gamsii significantly inhibited the growth of R. solani in the soil in situ and there was a general suppressive effect of the natural microbiome.


Assuntos
Antibiose , Rhizoctonia/crescimento & desenvolvimento , Microbiologia do Solo , Trichoderma/fisiologia , Contagem de Colônia Microbiana , Densidade Demográfica , Dinâmica Populacional , Reação em Cadeia da Polimerase em Tempo Real
18.
J Appl Oral Sci ; 27: e20180514, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31166551

RESUMO

OBJECTIVES: The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention. METHODOLOGY: Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05). RESULTS: M. urundeuva All. at 100, 10 and 0.1 µg/mL and Q. grandiflora Mart. at 100 and 0.1 µg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 µg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 µg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions. CONCLUSIONS: The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.


Assuntos
Anacardiaceae/química , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Myrtales/química , Extratos Vegetais/farmacologia , Desmineralização do Dente/prevenção & controle , Animais , Cariostáticos/farmacologia , Bovinos , Contagem de Colônia Microbiana , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/microbiologia , Ácido Láctico/metabolismo , Lactobacillus/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microrradiografia/métodos , Folhas de Planta/química , Polissacarídeos Bacterianos/metabolismo , Reprodutibilidade dos Testes , Saliva/química , Streptococcus mutans/efeitos dos fármacos
19.
J Microbiol Immunol Infect ; 52(4): 638-647, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31239204

RESUMO

BACKGROUND: The emergence of multiple-antibiotic-resistant (MAR) Salmonella has been a serious threat worldwide. Salmonella can invade into host cells and evade the attacks of host humoral defenses and antibiotics. Thus, a new antibacterial agent capable of inhibiting intracellular Salmonella is highly needed. METHODS: The anti-intracellular activity and cytotoxicity of drugs on intracellular bacteria and macrophages were assayed using intracellular CFU assay and MTT cell viability assay, respectively. The uptake of gentamicin into macrophage and the effect of autophagy inhibitor on loxapine's anti-intracellular Salmonella activity were assessed by using image-based high-content system. The expression of bacterial genes was measured by real-time PCR. The efflux pump activity of bacteria was measured by Hoechst accumulation assays. RESULTS: With our efforts, an antipsychotic drug, loxapine, was identified to exhibit high potency in suppressing intracellular MAR S. Typhimurium, Staphylococcus aureus, Shigella flexneri or Yersinia enterocolitica. Subsequent investigations indicated that loxapine's anti-intracellular bacteria activity was not associated with increased penetration of gentamicin into bacteria and macrophages. Loxapine didn't inhibit bacterial growth in broth at concentration up to 500 µM and has no effect on Salmonella's type III secretion system genes' expression. Blockage of autophagy also didn't reverse loxapine's anti-intracellular activity. Lastly, loxapine suppressed bacterial efflux pump activity in all bacteria tested. CONCLUSION: Altogether, our data suggested that loxapine might suppress intracellular bacteria through inhibiting of bacterial efflux pumps. In light of its unique activity, loxapine represents a promising lead compound with translational potential for the development of a new antibacterial agent against intracellular bacteria.


Assuntos
Antibacterianos/farmacologia , Antipsicóticos/farmacologia , Loxapina/farmacologia , Macrófagos/microbiologia , Salmonella typhimurium/efeitos dos fármacos , Animais , Autofagia/efeitos dos fármacos , Proteínas de Bactérias/genética , Sobrevivência Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Gentamicinas/farmacologia , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Camundongos , Testes de Sensibilidade Microbiana , Fenotiazinas/farmacologia , Células RAW 264.7 , Salmonella typhimurium/genética , Salmonella typhimurium/crescimento & desenvolvimento , Sorogrupo , Shigella flexneri/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Sistemas de Secreção Tipo III/efeitos dos fármacos , Sistemas de Secreção Tipo III/genética , Yersinia enterocolitica/efeitos dos fármacos
20.
World J Microbiol Biotechnol ; 35(7): 100, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31222403

RESUMO

The spontaneously fermented curdled milk product from Burkina Faso, lait caillé is prepared by traditional processing from raw unpasteurised milk. The fermentation lasts 1-3 days. This study aims to identify the predominant microbiota involved in lait caillé fermentation from cow milk. A survey on lait caillé end-products from local markets showed pH ranges of 3.5 to 4.2. Counts of total lactic acid bacteria (LAB) were 7.8 ± 0.06 to 10.0 ± 0.03 log CFU/g and yeast counts were 5.3 ± 0.06 to 8.7 ± 0.01 log CFU/g, together with considerate amounts of Enterobacteriaceae < 3.00 to 8.4 ± 0.14 log CFU/g. Sampling throughout the entire fermentation of lait caillé was performed at a traditional house-hold production site. A drop in pH from 6.7 ± 0.01 at 0 h to 4.3 ± 0.08 in the end-product (59 h) was found. Total LAB counts increased to 8.6 ± 0.02 log CFU/g in the end-product, while yeast and Enterobacteriaceae counts reached 6.4 ± 0.11 and 6.7 ± 0.00 log CFU/g, respectively. LAB and yeasts isolated during the fermentation were clustered by (GTG)5 repetitive-PCR fingerprinting followed by 16S and 26S rRNA gene sequencing, respectively. Microbial successions were observed with Leuconostoc mesenteroides being the predominant LAB followed by Pediococcus pentosaceus and Weissella paramesenteroides at the onset, while Lactococcus lactis and Enterococcus spp. where the predominant LAB after 7 h of fermentation. During the first 18 h Candida parapsilosis was the dominant yeast species, while from 35 h to the end-product, Saccharomyces cerevisiae predominated. The microbial safety risk pointed out in this study, showed the need for implementation of good manufacturing practices including pasteurisation and use of well-defined starter cultures.


Assuntos
Produtos Fermentados do Leite/microbiologia , Microbiota/genética , Burkina Faso , Contagem de Colônia Microbiana , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Enterococcus/genética , Enterococcus/isolamento & purificação , Fermentação , Manipulação de Alimentos , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillales/genética , Lactobacillales/isolamento & purificação , Lactococcus lactis/genética , Lactococcus lactis/isolamento & purificação , RNA Ribossômico/genética , RNA Ribossômico/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , Análise de Sequência de RNA , Leveduras/genética , Leveduras/isolamento & purificação
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