Inhibition of Sodium Hypochlorite Antimicrobial Activity in the Presence of Bovine Serum Albumin

Introduction: This study investigated the inhibition of the antimicrobial activity of sodium hypochlorite (NaOCl) by bovine serum albumin (BSA). The killing of Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, and Escherichia coil by NaOCl in concentrations from 2% to 0.03% was measured in the presence of BSA in concentrations between 6.7% and 0.1%. Methods: NaOCl, BSA, and microorganism suspensions were mixed, and, after 30 seconds, 6 minutes, and 30 minutes, samples were taken and NaOCl was inactivated by 5% sodium thiosulphate. The microbes were incubated in tryptic soy broth broth for up to 7 days for the detection of growth. Results: All microorganisms were killed within 30 seconds by 0.03% NaOCl when BSA was not present. High concentrations of BSA significantly reduced the antimicrobial activity of NaOCl against the four species. Conclusions: The inhibition of sodium hypochlorite by BSA was directly dependent on their quantitative relationships. The result partly explains the poorer performance in vivo of NaOCl as compared to in vitro experiments. (J Endod 2010;36:268-271)

Effect of Three Methods for Cleaning Dentures on Biofilms Formed In Vitro on Acrylic Resin

Purpose: The aim of this study was to evaluate the effect of three denture hygiene methods against different microbial biofilms formed on acrylic resin specimens. Materials and methods: The set (sterile stainless steel basket and specimens) was contaminated (37 degrees C for 48 hours) by a microbial inoculum with 106 colony-forming units (CFU)/ml (standard strains: Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Enterococcus faecalis; field strains: S. mutans, C. albicans, C. glabrata, and C. tropicalis). After inoculation, specimens were cleansed by the following methods: (1) chemical: immersion in an alkaline peroxide solution (Bonyplus tablets) for 5 minutes; (2) mechanical: brushing with a dentifrice for removable prostheses (Dentu Creme) for 20 seconds; and (3) a combination of chemical and mechanical methods. Specimens were applied onto a Petri plate with appropriate culture medium for 10 minutes. Afterward, the specimens were removed and the plates incubated at 37 degrees C for 48 hours. Results: Chemical, mechanical, and combination methods showed no significant difference in the reduction of CFU for S. aureus, S. mutans (ATCC and field strain), and P. aeruginosa. Mechanical and combination methods were similar and more effective than the chemical method for E. faecalis, C. albicans (ATCC and field strain), and C. glabrata. The combination method was better than the chemical method for E. coli and C. tropicalis, and the mechanical method showed intermediate results. Conclusion: The three denture hygiene methods showed different effects depending on the type of microbial biofilms formed on acrylic base resin specimens.

Chronic Suppurative Otitis Media in Cleft Palate: Microorganism Etiology and Susceptibilities

Objective: To investigate the microbial etiology of suppurative chronic otitis media (SCOM) in patients with complete cleft lip and palate and isolated cleft palate and to determine the sensitivity of isolated microorganisms to antibiotics by drug diffusion from impregnated discs in agar and the minimum inhibitory concentration of each drug to these microorganisms by drug dilution in agar. Design/Patients: Effusion samples of SCOM obtained from 40 patients with cleft lip and palate registered at the Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo, at Bauru, Brazil, were bacteriologically analyzed by cultures. The isolated bacteria were submitted to an in vitro susceptibility test to clinically used drugs. Results: Positive cultures were obtained in 100% of studied cases. Among the 57 strains observed, the most frequent were Pseudomonas aeruginosa (35%), Staphylococcus aureus (15.5%), Enterococcus faecalis (14%), and Proteus mirabilis (12%). The frequency of Gram-negative bacilli (enterobacteriaceae and nonfermentative bacilli) was 67%. Pseudomonas aeruginosa presented the highest sensitivity to ciprofloxacin, and enterobacteriaceae exhibited the highest sensitivity to gentamicin. The strains of S. aureus and E. faecalis presented the highest sensitivity to imipenem and sulfamethoxazole/trimethoprim, respectively. Conclusion: Patients with cleft lip and palate presenting with SCOM exhibited 100% positive cultures, with the highest frequency of Pseudomonas and enterobacteriaceae. With regard to the action of antibiotics, imipenem was effective against the four species of isolated microorganisms, followed by ciprofloxacin, which was effective against 75% of isolated species.

High-power diode laser in the disinfection in depth of the root canal dentin

Objective. The objective of this study was to evaluate the disinfection degree of dentine caused by the use of diode laser after biomechanical procedures. Study design. Thirty teeth were sectioned and roots were autoclaved and incubated for 4 weeks with a suspension of Enterococcus faecalis. The specimens were randomly divided into 3 groups (n = 10): G1, instrumented with rotary files, irrigated with 0.5% sodium hypochlorite and 17% EDTA-T, and then irradiated by 830-nm diode laser at 3 W; G2, the same procedures as G1 but without laser irradiation; and G3, irrigation with saline solution (control). Dentin samples of each third were collected with carbide burs and aliquots were sowed to count viable cells. Results. The disinfection degree achieved was 100% in G1 and 98.39% in G2, when compared to the control group (G3). Conclusion. Diode laser irradiation provided increased disinfection of the deep radicular dentin in the parameters and samples tested.

Comparison of Two Rotary Systems in Root Canal Preparation Regarding Disinfection

Introduction: The aim of the present study was to determine the disinfection of preparations carried out by using the Protaper or MTwo system in canals infected with Enterococcus faecalis. Methods: Twenty-eight distobuccal canals of upper molars were used, in which the canals were sterilized after being enlarged to #20 file and then contaminated with an inoculation of a culture of E. faecalis. After the incubation period, bacterial samples were collected and were seeded on plates for analysis of colony-forming units (CFU)/mL. The teeth were divided into 2 groups according to the rotary system used for instrumentation; 2 noninstrumented teeth served as the control group. Then bacterial samples were collected and were seeded on plates for analysis of CFU/mL again. The data obtained were evaluated by the Wilcoxon and Mann-Whitney U tests. Results: Bacterial reduction was 81.94% and 84.29%, respectively, in Pro Taper and Mtwo systems, and there was no statistically significant difference (P > .05). Conclusions: Both systems, Pro Taper and Mtwo, reduced the amount of bacteria in the mechanical disinfection of the root canal system, demonstrating that they are suitable for this purpose. (J Endod 2010;36:1238-1240)

The Challenges of Antimicrobial Resistance in Brazil

Brazil is a country with continental proportions with high geographic and economic diversity. Despite its medical centers of excellence, antimicrobial resistance poses a major therapeutic challenge. Rates of methicillin-resistant Staphylococcus aureus are up to 60% and are related to an endemic Brazilian clone. Local resistance to vancomycin in Enterococci was first related to Enterococcus faecalis, which differs from European and American epidemiology. Also, local Klebsiella pneumoniae and Escherichia coli isolates producing extended-spectrum beta-lactamases have a much higher prevalence (40%-50% and 10%-18%, respectively). Carbapenem resistance among the enterobacteriaceae group is becoming a major problem, and K. pneumoniae carbapenemase isolates have been reported in different states. Among nonfermenters, carbapenem resistance is strongly related to SPM-1 (Pseudomonasaeruginosa) and OXA-23 (Acinetobacter baumannii complex) enzymes, and a colistin-only susceptible phenotype has also emerged in these isolates, which is worrisome. Local actions without loosing the global resistance perspective will demand multidisciplinary actions, new policies, and political engagement.

Pt(II) and Ag(I) complexes with acesulfame: Crystal structure and a study of their antitumoral, antimicrobial and antiviral activities

Two new complexes of platinum(II) and silver(I) with acesulfame were synthesized. Acesulfame is in the anionic form acesulfamate (ace). The structures of both complexes were determined by X-ray crystallography. For K(2)[PtCl(2)(ace)(2)] the platinum atom is coordinated to two Cl(-) and two N-acesulfamate atoms forming a trans-square planar geometry. Each K(+) ion interacts with two oxygen atoms of the S(=O)(2) group of each acesulfamate. For the polymeric complex [Ag(ace)](n) the water molecule bridges between two crystallographic equivalent Agl atoms which are related each other by a twofold symmetry axis. Two Agl atoms, related to each other by a symmetry centre, make bond contact with two equivalent oxygen atoms. These bonds give rise to infinite chains along the unit cell diagonal in the ac plane. The in vitro cytotoxic analyses for the platinum complex using HeLa (human cervix cancer) cells show its low activity when compared to the vehicle-treated cells. The Ag(I) complex submitted to in vitro antimycobacterial tests, using the Microplate Alamar Blue (MABA) method, showed a good activity against Mycobacterium tuberculosis, responsible for tuberculosis, with a minimal inhibitory concentration (MIC) value of 11.6 mu M. The Ag(I) complex also presented a promising activity against Gram negative (Escherichia colt and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis) microorganisms. The complex K(2)[PtCl(2)(ace)(2)] was also evaluated for antiviral properties against dengue virus type 2 (New Guinea C strain) in Vero cells and showed a good inhibition of dengue virus type 2 (New Guinea G strain) replication at 200 mu M, when compared to vehicle-treated cells. (C) 2010 Elsevier Inc. All rights reserved.

Aspectos microbiológicos da bile de pacientes com suspeita de coledocolilitíase e suas repercussões no tratamento das infecções biliares

A infecção das vias biliares é uma doença freqüente com alta morbidade e mortalidade, que pode variar de 10 a 60% dependendo de sua gravidade. A causa mais comum desta infecção é a presença de cálculos na via biliar principal que propicia o surgimento de bacteriobilia. O profundo conhecimento das características microbiológicas da bile nos casos de coledocolitíase e infecção das vias biliares são fundamentais para o melhor diagnóstico desta infecção e escolha da antibioticoterapia a ser instituída. Assim, o objetivo deste estudo foi de caracterizar os principais aspectos microbiológicos da bile dos pacientes com e sem coledocolitíase e avaliar sua importância na escolha dos antimicrobianos para o tratamento da infecção das vias biliares. Foram analisados 33 pacientes que foram divididos em um grupo de 10 pacientes sem coledocolitíase (grupo controle) no momento da Colangiografia Endoscópica (CPER) e em outro grupo de 23 pacientes com coledocolitíase. A bile de todos os pacientes foi coletada no início do procedimento endoscópico, através de catater introduzido na via biliar. O exame de microscopia direta com coloração de Gram e as culturas da bile foram negativas nos 10 pacientes que não apresentaram coledocolitíase durante a CPER. Dos 23 pacientes com cálculos na via biliar principal, 19 (83%) apresentaram culturas positivas. Desses 19 pacientes com culturas de bile positivas, 18 (94,7%) apresentaram microorganismos detectáveis à microscopia direta com coloração de Gram. Apenas um paciente apresentou crescimento de germe anaeróbio (Bacteroides fragilis). O cultivo de 28 bactérias teve predominância de microorganismos Gram negativos (18 bactérias- 64,3%). Os germes isolados foram E. coli (9, 32,1%), Klebsiella pneumoniae (5, 17,9%), Enterococcus faecalis (5, 17,9%), Streptococcus alfa-haemoliticus (3, 10,7%), Streptococcus viridans (2, 7,1%), Enterobacter cloacae (2, 7,1%), Panteona aglomerans (1, 3,6%) e Pseudomonas aeruginosa (1, 3,6%). Todos os pacientes com microorganismos detectados pela microscopia direta com coloração de Gram tiveram crescimento bacteriano em suas culturas, por outro lado nenhum paciente com cultura negativa apresentou microoorganismos à microsopia direta ( p= 0,0005). Nesses casos, a microsopia direta apresentou uma especificidade de 100% e sensibilidade de 80%. A análise quantitativa das culturas da bile mostrou que das 19 culturas positivas, 12 (63,2%) tiveram pelo menos um germe com contagem superior a 105 ufc/ml. Todas as bactérias Gram positivas isoladas foram sensíveis à ampicilina, da mesma forma que todas as Gram negativas foram sensíveis aos aminoglicosídeos. Os achados deste estudo demonstram uma boa correlação entre a microscopia direta da bile com coloração de Gram e os achados bacteriológicos das culturas da bile coletada por colangiografia endoscópica retrógrada. O esquema terapêutico antimicrobiano tradicionalmente empregado em nosso hospital, que inclui a combinação de ampicilina e gentamicina, parece ser adequado, pois apresenta eficácia terapêutica contra os principais microorganismos responsáveis pela infecção das vias biliares.

Avaliação da atividade antibacteriana de extratos de llex paraguariensis A.St. Hill. ("Erva mate") frente a bactérias zoonóticas em saúde e produção animal.

Motivado pelo cultivo de erva mate no Rio Grande do Sul, basicamente dentro de unidades de produção familiar, bem como pelo considerável volume de biomassa descartada, resultante do corte dos ervais, procurou-se identificar possível atividade antibacteriana em cambitos e folhas de Ilex paraguariensis St. Hill, com ênfase a zoonoses de interesse em saúde e produção animal, bem como em saúde coletiva. Definiu-se a verificação da Intensidade de Atividade de Inibição Bacteriana (IINIB) e Intensidade de Atividade de Inativação Bacteriana (IINAB) de extratos hídricos (decocto), alcoólicos (alcoolatura) e hidroalcoólicos (tintura) sobre inóculos padronizados de Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 19433), Samonella Enteritidis (ATCC 11076) e Escherichia coli (ATCC 11229). Os extratos vegetais alcoólicos foram preparados com folhas frescas, os hidroalcoólicos com os talos desidratados (cambitos) e os decoctos, tanto de folhas como de talos, com material desidratado. Todas as quatro formas de extração apresentaram capacidade de inativação e/ou inibição seletivas sobre os inóculos bacterianos, porém os extratos à base de álcool de cereais foram os que apresentaram os melhores resultados. Dentre as bactérias, a Salmonella Enteritidis demonstrou maior sensibilidade, seguida por Enterococcus faecalis. Posteriormente, estas duas amostras foram submetidas a testes sob tempo de exposição de 5, 15, 30 e 60 minutos, na ausência e na presença de matéria orgânica (soro bovino inativado), confrontando-as com alcoolatura de folhas e hidroalcoolatura de cambitos, por estes terem obtido maior ação antibacteriana sobre os agentes testados nos testes iniciais de IINIB e IINAB. Os decoctos de cambitos não corresponderam às expectativas iniciais, sendo que as alcoolaturas, tanto de folhas quanto de cambitos, apresentaram resultados eficazes. Tanto o tempo de exposição como a presença de matéria orgânica interferiram na sensibilidade apresentada por Salmonella Enteritidis e Enterococcus faecalis, positiva e negativamente, respectivamente.

Análise farmacognóstica e atividade antibacteriana de extratos vegetais empregados em formulação para a higiene bucal

A utilização de extratos vegetais vem se tornando uma alternativa importante para a prevenção de doenças periodontais. Este trabalho objetivou desenvolver uma formulação de enxagüatório bucal, contendo, em associação, extratos hidroalcoólicos de Rosmarinus officinalis, Plantago major, Tabebuia impetiginosa, Achillea millefollium e Nasturtium officinale; avaliar sua composição farmacognóstica e sua atividade antibacteriana, como também da fórmula proposta. Foram realizados estudos de pré-formulação e análises farmacognósticas para as espécies vegetais. A atividade antibacteriana in vitro foi observada por meio dos métodos de difusão em disco de papel, por hole- plate e por template, frente a Staphylococcus aureus, Bacillus subtilis, Escherichia colik, Enterococcus faecalis e Pseudomonas aeruginosa. A concentração inibitória mínima (CIM) foi determinada por meio do método de macrodiluições sucessivas em caldo. Os resultados obtidos apresentaram-se de acordo com o histórico farmacognóstico das drogas estudadas. Todas as bactérias foram inibidas pelos extratos, observando-se que as espécies S. aureus e B. subtilis mostraram, aparentemente, maior sensibilidade. A CIM variou, em relação a sensibilidade de cada espécie bacteriana estudada, de 312,5 µL/mL a 1250 µL/mL para os extratos vegetais e de 625 µL/mL a 2500 µL/mL para o enxaguatório bucal. São necessários estudos complementares para a confirmação da eficácia deste produto e sua utilização na prevenção de doenças periodontais.

Antibacterial effectiveness of peracetic acid and conventional endodontic irrigants

Este estudo avaliou, in vitro, a atividade antibacteriana de soluções irrigadoras convencionais e experimentais sobre Enterecoccus faecalis. As seguintes substâncias foram avaliadas por teste de contato direto: hipoclorito de sódio (NaOCl) a 2,5%, clorexidina (CHX) a 2%, ácido peracético a 1%. Após diferentes períodos de contato (30 s, 1, 3 e 10 min), um agente neutralizante foi empregado. Diluições decimais seriadas foram realizadas e semeadas em placas de tryptic soy agar (TSA). O número de unidades formadoras de colônia por mililitro (UFC/mL) foi determinado. Solução salina foi utilizada como controle negativo. Ambos, NaOCl a 2,5% e CHX a 2%, eliminaram E. faecalis após 30 s de contato. O ácido peracético reduziu a contagem bacteriana em 86% após 3 min e eliminou completamente E. faecalis após 10 min. Estes resultados permitem concluir que o ácido peracético a 1% é efetivo sobre E. faecalis, apesar de sua ação mais lenta quando comparado ao NaOCl a 2,5% e CHX a 2%.

Bacterial leakage evaluation of root canals filled with different endodontic sealers

Objective. The objective of this study was to evaluate the sealing ability of AH Plus, Epiphany, Acroseal, Endofill, and Polifil after active lateral condensation technique, by using a bacterial test, during 64 days.Study design. One hundred bovine incisors were cleaned and shaped; then they were filled with the endodontic sealers and adapted into a microcentrifuge tube. The setup root/microcentrifuge tube was added to glass flasks containing Brain Heart Infusion broth. A culture of Enterococcus faecalis was inserted into the upper chamber of each assembly. Daily leakage was evaluated through the broth turbidity.Results. The results were submitted to statistical analysis (Kaplan-Meier method, Kruskal-Wallis and Dunn tests).Conclusions. AH Plus and Endofill had the worst sealing ability when compared with Polifil, which showed the least leakage. Acroseal and Epiphany showed a tendency toward having an intermediate behavior; however, there was no significant difference among Acroseal, Epiphany, and the other sealers. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: e56-e60)

Antibacterial effectiveness of several irrigating solutions and the Endox Plus system - an ex vivo study

Aim To compare the ex vivo antibacterial effectiveness of the Endox Plus system and sodium hypochlorite (NaOCl) in combination with BioPure MTAD (Tulsa Dental, Tulsa, OK, USA) or with EDTA in Enterococcus faecalis-contaminated root canals.Methodology After initial preparation, the root canals of 70 single-rooted human teeth were inoculated with E. faecalis (ATCC 29212) and incubated for 21 days. Specimens were divided into five groups: Endox Plus/saline; 2.5% NaOCl/MTAD; 2.5% NaOCl/EDTA; saline (positive control); negative control (root canals not prepared, nor irrigated). Samples were collected using paper points. Microbiological analysis evaluated the number of CFUs. Data were analysed by anova and Tukey tests at 0.05 significance.Results All specimens had bacterial growth after the incubation period, with similar CFU per mL counts (P > 0.05). After chemo-mechanical preparation, the number of bacteria in all groups reduced, except for the negative control. No significant differences were observed between 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA, but these groups had lower CFU counts than the other groups (P < 0.05). In the final samples, an increase in the bacterial counts was observed for Endox Plus/saline, 2.5% NaOCl/MTAD, 2.5% NaOCl/EDTA and saline (P < 0.05) with no significant differences between these groups.Conclusions This ex vivo study revealed that the Endox Plus system was associated with a reduced antibacterial effectiveness compared with conventional irrigation using 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA. All irrigation procedures allowed recovery of bacteria 7 days after treatment, demonstrating persistence of contamination within the root canal system.

Inhibition of Sodium Hypochlorite Antimicrobial Activity in the Presence of Bovine Serum Albumin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bacterial leakage in root canals filled with conventional and MTA-based sealers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)