Biofilm formation by Staphylococcus aureus and Salmonella spp. under mono and dual-species conditions and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite

Abstract The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p < 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p < 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.

Aggregatibacter actinomycetemcomitans en periodontitis crónica en individuos de Corrientes, Argentina: estudio preliminar / Aggregatibacter actinomycetemcomitans in chronic periodontitis of individuals from Corrientes, Argentina: a preliminary study

Objetivo: establecer la prevalencia de Aggregatibacter actinomycetemcomitans en pacientes con periodontitis crónica en distintos estadios yla distribución de serotipos, utilizando la técnica de reacción en cadena de la polimerasa. Materiales y métodos: participaron 54 sujetos, entre 35 y 65 años de edad, con diagnóstico de periodontitis crónica. La periodontitis se clasificó en leve, moderada y severa. Como grupo control se incluyeron 24 sujetos sin periodontitis, con los mismos parámetros de inclusión. Para la detección de Aggregatibacter actinomycetemcomitans se procesaron muestras de placa subgingival obtenidas con cono de papel absorbente, conservadas a -20ºC hasta su procesamiento. El ácido dexorribonucleico se extrajo por el método de bromuro de cetiltrimetilamonio y se utilizó la técnica de reacción en cadena de polimerasa para su identificación y serotipado. Resultados: los resultados de las reacciones fueron leidos por electroforesis en geles de agarosa teñidos con bromuro de etidio y la visualización fue realizada por transiluminación ultravioleta. La prevalencia de A. actinomycetemcomitans en periodontitis crónica fue del 14,91 por ciento; el serotipo más frecuente fue el b. No se obtuvieron diferencias estadísticamente significativas entre los grupos con y sin periodontitis (p=0,064), ni entre los estadios de periodontitis y el serotipo presente (p=0,2139). Conclusión: aunque los resultados coinciden con la bibliografía, sería conveniente repetir el estudio sobre una muestra mayor.

Preparation and characterization of rifampin loaded mesoporous silica nanoparticles as a potential system for pulmonary drug delivery

The goal of this research is to determine the feasibility of loading rifampin into mesoporous silica nanoparticles. Rifampin was selected as a model lipophilic molecule since it is a well-documented and much used anti tuberculosis drug. The mesoporous silica nanoparticles were prepared by using tetraethyl ortho silicate and cetyltrimethyl ammonium bromide [as surfactant]. The prepared nanoparticles were characterized in terms of their particle size measurement and porosimetry. The results showed that the particle size is 218 +/- 46 nm [mean +/- SD] and surface area is 816 m[2]g[-1]. In order to load rifampin within the mesopores, adsorption experiments using three different solvents [methanol, water and dimethyl sulfoxide] were carried out. The loading procedure resulted in a significant improvement in the amount of rifampin loaded into mesoporous silica nanoparticles and methanol was found to be a suitable solvent, providing a drug entrapment efficiency of 52 %. Rifampin loaded nanoparticles underwent different in-vitro tests including, SEM and drug release. The in-vitro drug release was investigated using buffer phosphate [pH=7.4]. Regarding the drug release study, a biphasic pattern of release was observed. The drug-loaded mesoporous silica nanoparticles were capable of releasing 95% of their drug content after 24 h, following a faster release in the first four hours. The prepared rifampin loaded nanoparticles seem to have potential for use as a pulmonary drug delivery

Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals / 国际口腔科学杂志·英文版

Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. The roots were randomly divided into three experimental groups (n=26) according to the final irrigating solution: Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P<0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.

Pulp Tissue Dissolution Capacity of Sodium Hypochlorite Combined with Cetrimide and Polypropylene Glycol

This study evaluated the influence of the addition of cetrimide and polypropylene glycol to sodium hypochlorite (NaOCl) on its capacity to dissolve pulp tissue. Bovine pulp fragments with standardized weight and volume were immersed for 5, 15 and 30 min in 2 mL of NaOCl and Hypoclean (NaOCl added with cetrimide and polypropylene glycol) solutions at 5.25%, 2.5%, 1%, 0.5% and 0.25% and afterwards re-weighted. Distilled water was used as a control. The percentage of tissue loss was considered for statistical analysis (univariate ANOVA, SPSS, v. 17.0) at 5% significance level. There was no tissue dissolution in the control group. NaOCl added with surfactants (Hypoclean) dissolved more pulp tissue (p<0.05) than NaOCl alone. Tissue dissolution was directly dependent on the concentration of solutions (p<0.05), and also on the time range (p<0.05). The combination of NaOCl at high and low concentrations with the surfactants cetrimide and polypropylene glycol increased significantly its capacity to dissolve pulp tissue.

Este estudo avaliou a influência da adição de cetramida e polipropilenoglicol ao hipoclorito de sódio (Hypoclean) na capacidade de dissolução pulpar do hipoclorito de sódio (NaOCl). Fragmentos de tecido pulpar bovino, com peso e volume padronizados foram imersos por períodos de 5, 15 e 30 min em 2 mL de NaOCl ou Hypoclean nas concentrações 5,25%, 2,5%, 1%, 0,5% e 0,25%. Após a imersão nas soluções testadas, os fragmentos foram novamente pesados. Como controle, foi utilizada água destilada. O percentual de perda tecidual foi considerado para análise estatística (ANOVA univariada, SPSS, v. 17.0). Não houve dissolução tecidual no grupo controle. A solução de NaOCl combinada a surfactantes (Hypoclean) dissolveu um maior percentual de tecido pulpar (p<0,05) que o NaOCl sem associações. A dissolução tecidual foi diretamente dependente da concentração das soluções (p<0,05), assim como do tempo de exposição às soluções (p<0,05). A adição dos surfactantes cetramida e polipropilenoglicol ao NaOCl em concentrações altas e baixas aumentou significativamente sua capacidade de dissolução do tecido pulpar.

Antimicrobial solutions used for root canal disinfection

This article discusses the significance of root canal disinfectants and comments on how these can be used professionally. The complex root canal system is inhabited with different microbes in periapical periodontitis. There is no particular disinfectant that alone satisfactorily fulfills the entire functions essential for irrigation. Best possible irrigation is found on the combined use of two or more disinfectant, in a particular sequence. Sodium hypochlorite is the most commonly recommended endodontic irrigant, in spite of some adverse reactions. Chlorhexidine, Iodine and Chelators are successful against several bacteria and viruses, mainly in retreatment cases. Newer root canal irrigants like MTAD [Mixture of Tetracycline, Acid and Detergent], Tetraclean, Photo-activated disinfection, Electronically Activated Water, Ozonated water and lasers have potential to maximize root canal disinfection. Currently these newer irrigants could be used as an adjunct to NaOCl, while investigators are continuously looking for the subtle ideal root canal irrigant

Ex vivo microbial leakage after using different final irrigation regimens with chlorhexidine

Objective: To assess the influence of final irrigation protocols with chlorhexidine in the coronal leakage of Enterococcus faecalis in filled root canals. Material and Methods: Seventy single-root canals from extracted teeth were prepared using ProTaper instruments. The irrigation protocol accomplished an alternating irrigation with 5 mL of 2.5% sodium hypochlorite (NaOCI) and 17% EDTA between each file. The teeth were randomly divided into four experimental groups (n=15) according to the final irrigation regimen: group 1, without final irrigation; group 2, irrigation with 10 mL 2.0% chlorhexidine (CHX); group 3, with a final application of EC40™; and group 4, irrigation with the combination (1:1) of 0.2% CHX + 0.1% cetrimide (CTR). All the teeth were mounted in a two-chamber apparatus and the coronal access was exposed to E. faecalis. The presence of turbidity in the BHI broth over a period of 180 days was observed. The Friedman test was used for statistical analysis. Results: EC40™ varnish showed the least leakage at 180 days, and was statistically similar to 2% CHX. No significant differences were observed between the group without final irrigation and the 2% CHX group or 0.2% CHX + 0.1% CTR. Conclusions: In this ex vivo study, EC40™ showed the longest delayed coronal leakage of E. faecalis, although without significant differences from 2% CHX.

Effect of antibacterial agents on the surface hardness of a conventional glass-ionomer cement

In atraumatic restorative treatment (ART), caries removal with hand excavation instruments is not as efficient as that with rotary burs in eliminating bacteria under the glass ionomer cements (GICs). Thus, different antibacterial agents have been used in recent studies to enhance the antibacterial properties of the GICs, without jeopardizing their basic physical properties. OBJECTIVE: The objective of this study was to evaluate the effect of antibacterial agents on the surface hardness of a conventional GIC (Fuji IX) using Vickers microhardness [Vickers hardness number (VHN)] test. MATERIAL AND METHODS: Cetrimide (CT), cetylpyridinium chloride (CPC) and chlorhexidine (CHX) were added to the powder and benzalkonium chloride (BC) was added to the liquid of Fuji IX in concentrations of 1 percent and 2 percent, and served as the experimental groups. A control group containing no additive was also prepared. After the completion of setting reaction, VHN measurements were recorded at 1, 7, 15, 30, 60, and 90 days after storage in 37°C distilled water. A one-way ANOVA was performed followed by a Dunnett t test and Tamhane T2 tests and also repeated measurements ANOVA was used for multiple comparisons in 95 percent confidence interval. RESULTS: VHN results showed significant differences between the control and the experimental groups at all time periods (p<0.05 for all). Significant differences were observed between all study periods for individual groups (p<0.05). After 7 days, VHNs were decreased in all experimental groups while they continued to increase in the control group. BC and CHX groups demonstrated the least whereas CT and CPC groups exhibited most adverse effect on the hardness of set cements. CONCLUSIONS: Despite the decreased microhardness values in all experimental groups compared to the controls after 7 up to 90 days, incorporating certain antibacterial agents into Fuji IX GIC showed tolerable microhardness alterations within the limitations of this in vitro study.

Evaluation of the antibacterial and physical properties of glass ionomer cements containing chlorhexidine and cetrimide: An in-vitro study.

Background: Incorporation of antibacterial agents frequently results in changes in the physical properties of restorative materials. Materials and Methods: This in-vitro study investigated the antibacterial and physical properties of Glass ionomer cement (GIC) with chlorhexidine and cetrimide, to determine the optimal concentration, for incorporation of these agents to obtain antibacterial GICs for use with the Atraumatic restorative treatment approach. This was assessed using the agar diffusion test. Chlorhexidine diacetate and cetrimide were added to Glass ionomer cement type-IX (GIC-FUJI IX) at 1 and 2% W/W ratio. The experimental GIC specimens were placed on agar plates inoculated with Lactobacillus casei, and the area of inhibition was calculated after 48 hours. Results: All the experimental GICs exhibited inhibition of bacteria, but the sizes were dependent on the concentration of the antibacterial agent. Incorporation of chlorhexidine diacetate and cetrimide, at 2%, significantly decreased the compressive strength, and the setting time was extended a little by the addition of any concentration of chlorhexidine and cetrimide. Conclusions: The present study demonstrated that experimental GICs containing chlorhexidine diacetate and cetrimide were effective in inhibiting bacteria associated with caries, and incorporation of 1% cetrimide was optimal to give the appropriate antibacterial and physical properties.

Preparation of ATP-2Na loaded liposome and its effect on tissues energy state in myocardial ischemic mice / 药学学报

The aim of this study is to improve liposome encapsulation efficiency of water soluble drug ATP-2Na with hydrophobic ion pairing method, and evaluate its effect on tissues energy state in myocardial ischemia mice. Ion pair complex of ATP-2Na with HTAB was prepared first; then the liposomes were prepared by ethanol injection method. The size and zeta potential of ATP-2Na liposome were investigated. Its effect on tissues energy state in myocardium ischemia mice was evaluated by detecting ATP-2Na concentration in tissues and blood after injection in comparison to ATP-2Na solution. The diameters and zeta potential of ATP-2Na liposomes were (144.0 +/- 2.7) nm and (+16.2 +/- 1.6) mV, respectively. The encapsulation efficiency was (85.02 +/- 2.31) %. The in vitro drug release pattern from liposomes matches with Weibull equation. Compared with ATP-2Na solution, ATP-2Na liposome increased the ATP concentration of blood in myocardial ischemic mice very significantly; compared with blank, ATP-2Na liposome increased ATP content of myocardium and liver in myocaridal ischemic mice significantly, but ATP-2Na solution didn't show this effect. ATP-2Na liposome might have an advantage in improving tissue energy state on myocaridal ischemic animals.

Antimicrobial effect of MTAD, Tetraclean, Cloreximid, and sodium hypochlorite on three common endodontic pathogens.

Objectives: The aim of this in vitro study was to evaluate the antimicrobial action of BioPure MTAD (Dentsply Tulsa Dental, Johnson City, TN), Tetraclean, Cloreximid (a mixture of Chlorhexidine (CHX) digluconate and Cetrimide), and 5.25% NaOCl (Ogna Laboratori Farmaceutici, Milano, Italy) against selected endodontic pathogens (Enterococcus faecalis, Porphyromonas gingivalis, and Prevotella intermedia). Materials and Methods: The agar plate diffusion procedure was used to observe the antimibrobial activity of irrigants. Results: Statistical analysis revealed significant effects of the different irrigants on the bacteria colonies. Treatment with 5.25% NaOCl induced a larger zone of microbial inhibition in Prevotella intermedia and Porphyromonas gingivalis (Tukey HSD post-test, P = 0.0001) when compare to MTAD, Tetraclean and CHX. Anyway, MTAD and Tetraclean were more effective to inhibit bacterial growth compared to CHX (P < 0.0001, Tukey HSD post-test). Furthermore, post hoc analysis revealed that MTAD and Tetraclean induced the largest zone of microbial inhibition of Enterococcus faecalis cultured under both aerobic and anaerobic conditions, when compared with 2% CHX and NaOCl (P < 0.0001, Tukey HSD post-test). The control group showed no microbial inhibition. Conclusion: 5.25% NaOCl showed a high antimicrobial activity against anaerobic bacteria. MTAD and Tetraclean showed a high action against both, strictly anaerobic and facultative anaerobic bacteria. Chlorexidine + Cetrimide (Cloreximid) showed the lowest antibacterial activity against both, facultative and strictly anaerobic bacteria tested.

Removal of bisphenol A from aqueous solution by hydrophobic sorption of hemimicelles

In this work, the hydrophobic sorption of hemimicelles was proposed as an innovative method for removing bisphenol A from aqueous solution with esterified carboxyl cotton as sorbent and cetyl trimethyl ammonium bromide as cationic surfactant. In order to optimize the sorption process, the effect of sorbent dose, initial pH, surfactant dose, sorbate concentration, contact time and temperature was investigated in batch system. The maximum value of bisphenol A removal appeared in the pH range 4-10. The bisphenol A removal ratio came up to the maximum value beyond 12 time of surfactant/bisphenol A. The isothermal data of bisphenol A sorption conformed well to the Langmuir model and the maximum sorption capacity [Qm] of esterified carboxyl cotton for bisphenol A was 87.72 mg/g. The bisphenol A removal equilibrium was reached within about 4 h and the removal process could be described by the pseudo-second-order kinetic model. The thermodynamic study indicated that the bisphenol A sorption process was spontaneous and exothermic

Purification of large-scale plasmid DNAs by selective precipitation with cetyltrimethylammonium bromide / 生物工程学报

Following Escherichia coli lysis with alkali, cetyltrimethylammonium bromide (CTAB) was directly titrated into the supernatant. An easy and feasible technology for plasmid purification was established with the optimized proportion between the quantity of CTAB and plasmid, combined with the specific solution for DNA release and TritonX-114 for endotoxin removal. Quality detection showed that the purified plasmid was free of contamination of host RNA. The host bacterial genomic DNA, endotoxin and bacterial protein were less than 10 microg, 50 EU and 10 microg per mg plasmids, respectively. The ratio of OD260/OD280 was between 1.75-1.85. Eighty percent of the prepared plasmids were presented in the supercoiled form. The plasmid purified with this technology can satisfy all criteria stipulated by FDA. The main advantages of the technology include the avoidance of animal-derived enzymes such as ribonucleases A, Proteinase K and toxic reagents like chloroform and phenol. In addition, the technology has low cost and no pollution.

A micromethod for high throughput RNA extraction in forest trees

A large quantity of high quality RNA is often required in the analysis of gene expression. However, RNA extraction from samples taken from woody plants is generally complex, and represents the main limitation to study gene expression, particularly in refractory species like conifers. Standard RNA extraction protocols are available but they are highly time consuming, and not adapted to large scale extraction. Here we present a high-throughput RNA extraction protocol. This protocol was adapted to a micro-scale by modifying the classical cetyltrimethylammonium (CTAB) protocol developed for pine: (i) quantity of material used (100-200 mg of sample), (ii) disruption of samples in microtube using a mechanical tissue disrupter, and (iii) the use of SSTE buffer. One hundred samples of woody plant tissues/organs can be easily treated in two working days. An average of 15 /ig of high quality RNA per sample was obtained. The RNA extracted is suitable for applications such as real time reverse transcription polymerase chain reaction, cDNA library construction or synthesis of complex targets for microarray analysis.

Improvement on the activity of microbial transglutaminase with Streptomyces hygroscopicus by the addition of surfactant CTAB / 生物工程学报

Effect of CTAB addition on the accumulation of microbial transglutaminase (MTG) with Streptomyces hygroscopicus was investigated. The results showed that the addition of CTAB enhanced MTG accumulation, and the optimal addition time and concentration of CTAB were 32 h and 1%. The maximum MTG activity in the culture broth was 5.04 u/mL and increased by 21.8% compared with the control. With the addition of CTAB, pro-MTG was activated to become MTG. CTAB could enhance the production of pro-MTG by relieving the product inhibition, and the accumulation of MTG was improved.

Preoperative vaginal preparations for abdominal hysterectomy for the prevention of febrile morbidity: savlon douching vs povidone-iodine painting.

OBJECTIVE: To compare the effectiveness between savlon solution was douching and povidone-iodine solution painting for reducing febrile morbidity after total abdominal hysterectomy. Study design: Clinical trial. MATERIAL AND METHOD: One hundred and fifty patients at Srinagarind Hospital were scheduled for total abdominal hysterectomy (TAH). All subjects were non-randomly allocated to receive either savlon (1:1000 solutions) douching or povidone-iodine (1% solution) painting as pre-operative vaginal preparations. They also received Cefazolin 1 gm. intravenously before the operation. The principal outcome of the study was febrile morbidity. RESULTS: The overall rate of febrile morbidity was 21 percent. The incidence of febrile morbidity in the savlon vs. povidone-iodine groups was 16 (12/75) and 25 (19/75) percent, respectively. No statistically significant difference was found between the two groups (p-value = 0.16). The odds ratio was 1.78 (95%CI 0.79 to 3.99) and adjusted odds ratio was 2.09(95%CI 0.86 to 5.10) CONCLUSION: The effectiveness between savlon solution douching and povidone-iodine solution painting in conjunction with a prophylactic antibiotic before TAH for reducing febrile morbidity was not significant different.

A standardized protocol for genomic DNA isolation from Terminalia arjuna for genetic diversity analysis

For studying genetic diversity in natural populations of Terminalia, a medicinal plant, our attempts to isolate high quality DNA using several previously reported protocols and even modifications were unsuccessful. We therefore combined CTAB based isolation, and column based purification step, to isolate DNA from Terminalia arjuna. The DNA isolated using this standardized protocol was high in quality and suitable for restriction digestion and generation of random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP).

Sorption of wastewater containing reactive red X-3B on inorgano-organo pillared bentonite / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Bentonite is a kind of natural clay with good exchanging ability. By exchanging its interlamellar cations with various soluble cations, such as quaternary ammonium cations and inorganic metal ions, the properties of natural bentonite can be greatly improved. In this study, hexadecyltrimethylammonium bromide (HDTMA), CaCl(2), MgCl(2), FeCl(3), AlCl(3) were used as organic and inorganic pillared materials respectively to produce several kinds of Ca-, Mg-, Fe-, Al-organo pillared bentonites. Sorption of reactive red X-3B on them was studied to determine their potential application as sorbents in wastewater treatment. The results showed that these pillared bentonites had much improved sorption properties, and that the dye solutions' pH value had some effect on the performance of these inorgano-organo pillared bentonites. Isotherms of reactive X-3B on these pillared bentonites suggested a Langmuir-type sorption mechanism.

[Inhibitory Effects of Povidone-Iodine and Cetrimide-c Against Antibacterial Resistance Isolates of Escherichia coli and Enterococci]

Povidone Iodine and Cetrimide-c are important and valuable antiseptic compounds that have been used for many years, as disinfectant for wounds, burns, instruments and the environments such as surgical rooms in the hospitals. Recently, bacterial resistances to these antiseptics have been reported in multi-drugs resistance bacteria such as Enterococci, which are important causes of nosocomial infections. This study was done to confirm the antiseptic activity of these agents: In this study 5 isolates of Escherichia coli and 13 isolates of Enterococci being resistant or sensitive to at least 5 antibacterial agents, including vancomycin, isolated from urinary tract infections were used. The concentrations of 1:2, 1:5, 1:10, 1:20 and 1:100, of povidon Iodoine, and 1:200 and 1: 500 for cetrimide-c were used. Concentrations of 5x10[7] and 1x10[7] CFU/ml [Colony Forming Unit] of the bacteria were tested at room temperature in the presence of Povidone-Iodine and Cetrimide-c for 2, 10, 30 minutes. After treatment of the bacteria with antibacterial agents the bacteria were washed three times with phosphate buffer in order to remove the small amounts of antibacterial agents that were present in the inoculums used for bacterial growth. The results shows that in all cases the bacteria which were in contact with the antiseptic agents were unable to grow on solid media, whereas the control bacteria which were not in contact with the antibacterial agents had complete growth on the solid medium. Since resistance to the above mentioned antiseptics were not detected at different concentrations of antibacterial agents and the bacterial suspensions, these agents can still be used in the hospitals and other clinical centers for the disinfection of the skin and contaminated instruments. However continuous monitoring of the antiseptic activity of these compounds is recommended