Ex-vivo effect of intracanal medications based on ozone and calcium hydroxide in root canals contaminated with Enterococcus faecalis.

This ex vivo study evaluated the antibacterial effect of intracanal medications in root canals contaminated with Enterococcus faecalis. Fifty single-rooted human teeth were contaminated with E. faecalis (ATCC 29212) and incubated at 37°C for 21 days. The specimens were randomly divided into 5 groups according to the intracanal medication used: OZ-PG: ozonized propylene glycol; CH/CPMC: calcium hydroxide/camphorated paramonochlorophenol; OZ-PG/CH ozonized PG/CH; PC: positive control group (no medication); and NC: negative control group (no contamination). The samples were collected after 7 days (post-medication) and 14 days (final). Bacterial growth was checked by counting the colony-forming units (CFU). OZ-PG and CH/CPMC reduced significantly the CFU counts compared with PC in the post-medication and final samples, with no statistically significant differences among them. On the other hand, OZ-PG/CH did not reduce significantly the number of bacteria compared with PC. In conclusion, among the evaluated medications OZ-PG and CH/CPMC were the most effective against E. faecalis.

Ex-vivo Effect of Intracanal Medications Based on Ozone and Calcium Hydroxide in Root Canals Contaminated with Enterococcus faecalis

This ex vivo study evaluated the antibacterial effect of intracanal medications in root canals contaminated with Enterococcus faecalis. Fifty single-rooted human teeth were contaminated with E. faecalis (ATCC 29212) and incubated at 37°C for 21 days. The specimens were randomly divided into 5 groups according to the intracanal medication used: OZ-PG: ozonized propylene glycol; CH/CPMC: calcium hydroxide/camphorated paramonochlorophenol; OZ-PG/CH ozonized PG/CH; PC: positive control group (no medication); and NC: negative control group (no contamination). The samples were collected after 7 days (post-medication) and 14 days (final). Bacterial growth was checked by counting the colony-forming units (CFU). OZ-PG and CH/CPMC reduced significantly the CFU counts compared with PC in the post-medication and final samples, with no statistically significant differences among them. On the other hand, OZ-PG/CH did not reduce significantly the number of bacteria compared with PC. In conclusion, among the evaluated medications OZ-PG and CH/CPMC were the most effective against E. faecalis.

Resumo Este estudo ex vivo avaliou o efeito antibacteriano de medicações intracanal em canais radiculares contaminados com Enterococcus faecalis. Cinquenta dentes humanos unirradiculares foram contaminados com E. faecalis (ATCC 29212) e incubados a 37°C durante 21 dias. Os espécimes foram aleatoriamente divididos em diferentes grupos de acordo com a medicação intracanal utilizada: PG-OZ: propilenoglicol ozonizado; HC/PMCC: hidróxido de cálcio/paramonoclorofenol canforado; PG-OZ/CH; CP: controle positivo (sem medicação); e CN: controle negativo (sem contaminação). As amostras foram coletadas após 7 dias (pós-medição) e 14 dias (final). O crescimento bacteriano foi verificado através da contagem das unidades formadoras de colônias (UFC). PG-OZ e HC/PMCC reduziram estatisticamente o número de bactérias quando comparados com o CP nas amostras pós-medição e final, sem diferenças estatísticas entre si. Por outro lado, PG-OZ/HC não reduziu significativamente o número de bactérias em comparação com o CP. Em conclusão, entre as medicações avaliadas, PG-OZ e HC/PMCC foram as mais eficazes contra E. faecalis. .

Activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces

The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.

Antimicrobial properties and cytotoxicity of an antimicrobial monomer for application in prosthodontics.

PURPOSE: This study aimed to investigate the antimicrobial properties and cytotoxicity of the monomer methacryloyloxyundecylpyridinium bromide (MUPB), an antiseptic agent capable of copolymerizing with denture base acrylic resins. MATERIALS AND METHODS: The antimicrobial activity of MUPB was tested against the species Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus, and Streptococcus mutans. The minimum inhibitory and fungicidal/bactericidal concentrations (MIC, MFC/MBC) of MUPB were determined by serial dilutions in comparison with cetylpyridinium chloride (CPC). The cytotoxic effects of MUPB at concentrations ranging from 0.01 to 1 g/L were assessed by MTT test on L929 cells and compared with methyl methacrylate (MMA). The antimicrobial activity of copolymerized MUPB was tested by means of acrylic resin specimens containing three concentrations of the monomer (0, 0.3, 0.6% w/w). Activity was quantified by means of a disc diffusion test and a quantification of adhered planktonic cells. Statistical analysis employed the Mann-Whitney test for MIC and MFC/MBC, and ANOVA for the microbial adherence test (α = 0.05). RESULTS: MUBP presented lower MIC values when compared with CPC, although differences were significant for C. dubliniensis and S. mutans only (p= 0.046 and 0.043, respectively). MFC/MBC values were similar for all species except C. albicans; in that case, MUPB presented significantly higher values (p = 0.046). MUPB presented higher cytotoxicity than MMA for all tested concentrations (p < 0.001) except at 0.01 g/L. Irrespective of the concentration incorporated and species, there was no inhibition halo around the specimens. The incorporation of MUPB influenced the adhesion of C. albicans only (p = 0.003), with lower CFU counts for the 0.6% group. CONCLUSIONS: It was concluded that non-polymerized MUPB has an antimicrobial capacity close to that of CPC and high cytotoxicity when compared with MMA. The antimicrobial activity of MUPB after incorporation within a denture base acrylic resin did not depend on its elution, but was shown to be restricted to C. albicans.

Activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces.

The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.

A nonstaining and tasteless hydrophobic salt of chlorhexidine.

Chlorhexidine (CHX) remains one of the most effective and widely used antiplaque agents around the world, although its side effects still limit a long-term usage as the patient compliance for oral treatment with CHX. We hypothesize that a less water-soluble tetracation salt of CHX might be able to interact weakly with tooth enamel and oral taste cells, reducing those undesirable side effects of CHX. The chlorhexidine tetrapalmitate (CHXTP) was obtained and the antimicrobial activity was evaluated by hole-plate diffusion method and twofold tube dilution method; for measurement of its propensity to stain, we used the in vitro method of polymethylmethacrylate blocks in an infusion with black tea solution; the rate of its removal from oral cavity was studied by high-performance liquid chromatography measurement of CHX extracted from human saliva samples; and its effect on the human taste perception was evaluated by taste confusion matrix method. The results showed that CHXTP salt is very active against Streptococcus mutans, with no interference on taste perception and a low tendency to stain; however, chlorhexidine digluconate shows a better retention in saliva. The use of polyvinylpyrrolidone turned possible a nonstaining and tasteless CHXTP formulation to linger in mouth.

Formação de biofilme cristalinode Proteus mirabilis em cateterurológico / Formation of crystalline biofilm of Proteus mirabilis in urological catheter

O cateter uretral de longa permanência tem papel de destaque para pacientes com retenção urinária, com obstrução debexiga, com danos neurológicos e outras doenças. A urina contém sais minerais, que em pH alcalino se precipitam,cristalizam-se e bloqueiam o cateter urológico. A cristalização dos componentes iônicos da urina ocorre em presença de urease, enzima produzida por Proteus mirabilis. Esta bactéria tem a capacidade de aderir a superfícies inanimadas e formar biofilme. O objetivo deste estudo foi observar a formação de biofilme cristalino na superfície luminal de cateter urológicode látex siliconizado, por meio de microscópio eletrônico de varredura, após a canalização de urina artificial infectada com Proteus mirabilis. O experimento foi realizado in vitro,em sistema de fluxo dinâmico. A urina artificial, composta de sais de cálcio, magnésio, fosfatos, uréia e albumina deovo, foi infectada com Proteus mirabilis ATCC 25933. O fluxo da urina canalizada foi interrompido após a cristalização dos componentes iônicos. A cristalização foi observada após a alcalinização da urina. A microscopia eletrônica de varredura demonstrou a presença de cristais e morfologiastípicas de bacilos embutidos em massa amorfa. O presente estudo mostrou que a incrustação pode limitar o uso decateter urológico de longa permanência.

The indwelling urethral catheter has an important role for patients with urinary retention, bladder obstruction, neurological damage and other diseases. Urine contains minerals which precipitate in alkaline pH, crystallize and block the urological catheter. Thecrystallization of the ionic components of urine occurs in the presence of urease, an enzyme produced by Proteus mirabilis. This bacterium adheres to inanimate surfaces and forms biofilms. The aim of this study was to investigate the formation of crystalline biofilm on the luminal surface of siliconized latex catheters by means of scanning electron microscope, after channeling artificialurine infected with Proteus mirabilis. The experiment was performed in vitro using a dynamic flow system. The artificial urine compounds were salts of calcium, magnesium, phosphates, urea and egg albumin, and it was infected with Proteus mirabilis ATCC 25933. The urine flow was stopped after crystallization of the ionic components. Crystallization was observed afteralkalinization of urine. Scanning electron microscopy showed the presence of crystals and morphologies typical of bacilli embedded in an amorphous mass on the internal lumen of the catheter. Thepresent study showed that catheter encrustation may limit the use of long-term indwelling catheter.

Evaluation of the smear layer and hybrid layer in noncarious and carious dentin prepared by air abrasion system and diamond tips.

PURPOSE: To analyze the smear layer and the hybrid layer in noncarious and carious dentin prepared by different cutting instruments and restored with composite resin. STUDY DESIGN: Cavities were randomly prepared in 160 specimens (noncarious and artificial carious dentin) by high-speed diamond tips (KG Sorensen 1013), air abrasion system (Prepstart, Danville Engineering), ultrasonic tip (CVDentus 8.3231-1), and ultrasonic tip associated with ultrasonic cavitation by water for 10 s. Half of the cavities in each group were conditioned with 37% phosphoric acid for 15 s. The amount of smear layer and dentinal tubules present were analyzed using scanning electron microscopy and graded from 0 to 3. Cavities were prepared in another 20 noncarious specimens and 20 carious specimens and restored with adhesive composite resin system. The restorations were hemisected longitudinally and analyzed using scanning electron microscopy to evaluate the hybrid layer and resinous prolongation characteristics, using scores ranging from 1 to 6. RESULTS: The data were statistically analyzed using Kruskal-Wallis and Dunn tests at 5% of significance level. There was evidence that the most efficient smear layer removal was the acid etching in the noncarious dentin and the water ultrasonic cavitation in the carious dentin. The hybrid layer formed on the noncarious and carious dentin prepared by the ultrasonic tip was more regular than in the specimens prepared by high-speed diamond tip, with many resinous prolongations. CONCLUSION: The ultrasonic tip seems to be a promising tool for carious dentin cavity preparation.

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.

In vitro antimicrobial activity of Acroseal, Polifil and Epiphany against Enterococcus faecalis.

Using the agar diffusion method, this study evaluated the in vitro antimicrobial activity of the commercial endodontic sealers Acroseal and Epiphany, a castor-oil based experimental sealer, Polifil, and a primer agent (Epiphany self-etching primer), against Enterococcus faecalis. Zinc oxide and eugenol cement (ZOE) served as control. Five wells per dish were made at equidistant points and immediately filled with the test and control materials. After incubation of the dishes at 37 degrees C for 24 h and 48 h, the diameter of the zones of microbial growth inhibition produced around the wells was measured (in mm) with a millimeter rule. After 48 h, the diameters of the zones of microbial growth inhibition were the same as those observed at 24 h, only the substances continued to diffuse. Epiphany and Polifil did not show antibacterial activity (no formation of zones of microbial growth inhibition). The primer produced the largest zones of inhibition (17.62 mm) followed by Acroseal (7.25 mm) and ZOE (7.12 mm). E. faecalis was resistant to Epiphany and Polifil, while the primer and Acroseal sealer were effective against this microorganism under the tested conditions.

In vitro antimicrobial activity of acroseal, polifil and epiphany against Enterococcus faecalis

Using the agar diffusion method, this study evaluated the in vitro antimicrobial activity of the commercial endodontic sealers Acroseal and Epiphany, a castor-oil based experimental sealer, Polifil, and a primer agent (Epiphany self-etching primer), against Enterococcus faecalis. Zinc oxide and eugenol cement (ZOE) served as control. Five wells per dish were made at equidistant points and immediately filled with the test and control materials. After incubation of the dishes at 37ºC for 24 h and 48 h, the diameter of the zones of microbial growth inhibition produced around the wells was measured (in mm) with a millimeter rule. After 48 h, the diameters of the zones of microbial growth inhibition were the same as those observed at 24 h, only the substances continued to diffuse. Epiphany and Polifil did not show antibacterial activity (no formation of zones of microbial growth inhibition). The primer produced the largest zones of inhibition (17.62 mm) followed by Acroseal (7.25 mm) and ZOE (7.12 mm). E. faecalis was resistant to Epiphany and Polifil, while the primer and Acroseal sealer were effective against this microorganism under the tested conditions.

Utilizando o método de difusão em ágar, este estudo avaliou in vitro a atividade antimicrobiana dos cimentos endodônticos comerciais: Acroseal e Epiphany, um cimento experimental à base do polímero da mamona, Polifil, e um agente primer (primer auto-adesivo do sistema Epiphany), contra Enterococcus faecalis. O cimento de óxido de zinco e eugenol (OZE) serviu como controle. Cinco poços por placa foram feitos em pontos eqüidistantes e imediatamente preenchidos com os materiais testados e controle. Após a incubação das placas aos 37ºC por 24 e 48 h foram medidas as zonas de inibição do crescimento bacteriano ao redor dos poços (em mm) com uma régua milimetrada. Após 48 h, os diâmetros das zonas de inibição do crescimento bacteriano foram os mesmos observados às 24 h, apenas as substâncias continuaram a se difundir. Epiphany e Polifil não apresentaram atividade antibacteriana (não ocorreu a formação das zonas de inibição do crescimento bacteriano). Os maiores halos de inibição foram atribuídos ao primer (17,62 mm), seguido do Acroseal (7,25 mm) e OZE (7,12 mm). E. faecalis foi resistente ao Epiphany e Polifil, enquanto que o primer e o cimento Acroseal foram eficientes contra esse microrganismo nas condições testadas.

In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate.

Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.

In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate

Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12 percent chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.

Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme). A avaliação da atividade antimicrobiana foi realizada pela determinação da Concentração Inibitória Mínima (CIM). Os resultados mostraram que a solução teste inibiu o crescimento de microrganismos Gram-negativos e Gram-positivos da saliva dos voluntários, bem como das linhagens padrão na CIM de 1:20, enquanto que a CIM da diluição de clorexidina 0.12 por cento contra as mesmas bactérias foi de 1:80. Desta forma, apesar de o enxaguatório bucal testado apresentar atividade antimicrobiana in vitro superior à do placebo, esta foi inferior à da Clorexidina.

Análise farmacognóstica e atividade antibacteriana de extratos vegetais empregados em formulação para a higiene bucal / Herbal extracts in an experimental mouthwash: pharmacognostics analysis and antibacterial activity

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 æL/mL a 1250 æL/mL para os extratos vegetais e de 625 æL/mL a 2500 æL/mL para o enxaguatório bucal. São necessários estudos complementares para a confirmação da eficácia deste produto e sua utilização na prevenção de doenças periodontais.

In this study, herbs and hidroalcoholic extracts of Nasturtium officinale, Rosmarinus officinalis, Tabebuia impetiginosa, Plantago major and Achillea millefollium, were investigated for pharmacognostics analysis (flavonoids, alkaloids, tanins, saponins and antraquinones) and antibacterial activity (against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Enterococcus faecalis e Pseudomonas aeruginosa). In vitro antibacterial studies were carried by the disc diffusion method, hole plate and tamplate. The minimum inhibitory concentration (MIC) values were determinated by broth dilution method. The extracts were incorporated in mouthwash for periodontal diseases treatment. The pharmacognostics studies showed that herbs and extracts have substances groups described in literature. The antibacterial studies showed that extracts and mouthwash have some activity against all considered bacteria. S. aureus and B. subtilis showed, apparently, to be species more susceptible. Investigation of the MIC showed 312,5 æL/mL-1250 æL/mL for extracts and 625 æL/mL-2500 æL/mL for mouthwash. The studies served as initial quality control of the obtained cosmetic, enhancing anti-inflammatory (flavonoids) and/or antibacterial activities (tanins). However, new studies are necessary to confirm the cosmetic efficacy for treatment periodontal diseases.

Uso do teste com cloridato de trifenil tetrazólio (CTT) para detecção de bacteriúria sintomática e assintomática / Use of the triphenil tetrazolium chloride (TTC) test to detect symptomatic and asymptomatic bacteriuria

A infecção do trato urinário é geralmente definida como a presença de 10 5 ou mais UFC/mL de urina, obtida sem contaminação, na presença ou não de sintomatologia. É um grande problema clínico, especialmente entre as mulheres adultas. Usando métodos convencionais, o diagnóstico laboratorial dessas infecções é caro, consome muito tempo e é trabalhoso. Há necessidade de se obter um teste simples capaz de detectar números significantes de bactérias na urina. Com este objetivo, pretendeu-se reavaliar o teste com cloridrato de trifenil tetrazólio (CTT). Os resultados mostraram que o teste apresentou 84,3 de sensibilidade, 96,5...

Stpahylococcus aureus biofilms on central venous haemodialysis catheters

As infecções devido a biofilmes bacterianos são comuns em pacientes sob tratamento em hemodiálise. Neste estudo, 16 pacientes (7 homens, 9 mulheres, de 22 a 81 anos, média 50 anos de idade), com um total de 25 cateteres de hemodiálise (3 de triplo-lúmen e 22 de duplo-lúmen) de poliuretano inseridos em veia subclávia foram estudados. Os cateteres permaneceram no local de 3 a 91 dias (média de 47 dias). Os cateteres foram removidos devido ao: mau funcionamento (44%), suspeita de infecção relacionada ao cateter (20%), viabilidade de um acesso permanente (16%), remoção acidental (12%), sinais e sintomas de infecção no local da inserção do cateter (4%) e contaminação exógena (4%). Culturas positivas de ponta foram observadas em sete cateteres (28%), concomitantemente com três culturas positivas de sangue. Das culturas de sangue foram identificados Staphylococcus aureus (12%) e de uma das conexões foi isolado S. aureus. Biofilmes foram observados sobre todas as pontas de cateteres. Os S. aureus isolados do sangue e cateter (ponta e conexão) eram resistentes a pencilina e sensíveis a azitromicina, ciprofloxacina, clindamicina, cloranfenicol, gentamicina, oxacilina, rifampicina, sulfametoxazole, tetraciclina e vancomicina. As cepas de S. aureus isoladas de sangue, ponta de cateter e conexão foram consideradas idênticas devido à coincidência do perfil de sensibilidade. E similaridade genética, avaliada por meio de ribotipagem.

Detection of mixed microbial biofilms on central venous catheters removed from Intensive care Unit Patients

Cateteres venosos centrais inseridos em pacientes internados em unidade de terapia intensiva foram avaliados por métodos microbiológicos (cultura semi-quantitativa) e microscopia eletrônica de varredura a fim de detectar adesão microbiana e correlacionar com a cultura de sangue. Durante o período de estudo, foram avaliados 59 pacientes com cateter venoso central. A idade dos pacientes, sexo, sítio de insercão e tempo de permanência do cateter foram anotados. O cateter era de poliuretano não tunelizado e de único lúmen. O sangue para cultura foi coletado no momento da remocão do cateter. De 63 pontas de cateteres, 30 (47,6%) foram colonizadas e a infeccão encontrada em 5 (23,8%) cateteres. A infeccão foi mais prevalente em 26 pacientes (41,3%) com cateteres inseridos em veia subclávia do que nos 3 (3,2%) inseridos em veia jugular. A infeccão foi observada com mais freqüência em cateteres com tempo de permanência maior do que sete dias. Os microrganismos isolados incluíram 32 estafilococos coagulase-negativa (29,7%), 61 bactérias Gram-negativas (52,9%), 9 estafilcocos coagulase-positiva (8,3%) e 3 leveduras (2,7%). Como agentes causais de infeccões em unidade de terapia intensiva foram isolados E. aerogenes, P. aeruginosa, A. baumannii. Os antimicrobianos com maior atividade in vitro contra as bactérias Gram-negativas foram o imipenem e contra as Gram-positivas vancomicina, cefepime, penicilina, rifampicina e tetraciclina. As análises por microscopia eletrônica de varredura revelaram biofilmes sobre a superfície de todos os cateteres examinados.

Uso do método de cultura semi-quantitativa para estudo de bacteriemia relacionada ao cateter venoso central utilizado por pacientes em hemodiálise / Use of semiquantitative culture method to study bacteremia with central venous catheter related in hemodialysis patients

As infecções são as principais complicações resultantes do uso de cateter venoso central. Nesta pesquisa 25 pontas de cateter venoso central retiradas de veia subclávia de 16 pacientes ambulatoriais em tratamento de hemodiálise foram analisadas por cultura semi-quantitativa. Hemoculturas foram realizadas pelo sistema Bactec 9050. Os resultados obtidos por cultura semi-quantitativa mostraram que 10(40%) das pontas foram colonizadas (> 15 UFC) pelos seguintes microrganismos 3 (30%) Staphylococcus aureus, 2 (20%) Staphylococcus warneri, 1 (10%), Staphylococcus epidermidis, 1 (10%), Stenotrophomonas maltophilia e 3 (30%) bacilos difteróides. Das culturas de sangue foram isolados microrganismos identificados como Staphylococcus aureus.A bacteriemia foi observada em 12% dos pacientes e 40% das pontas dos cateteres estudados estavam colonizados.

Genetic polymorphism of Streptococcus mutans in Brazilian family members

O objetivo deste estudo foi determinar, através da técnica de reacão em cadeia da polimerase com primers arbitrários (AP-PCR) a capacidade de diferenciar clones geneticamente distintos de Streptococcus mutans e estabelecer o grau de similaridade intrafamilial para os isolados. Para o presente estudo, foram selecionadas 22 famílias brasileiras. Amostras de saliva foram coletadas de todos os membros das famílias. Das criancas com idade entre 5-18 meses obteve-se amostras de placa dental. Após o isolamento das colônias com características morfológicas, realizou-se a identificacão bioquímica com base na fermentacão de carboidratos. O polimorfismo genético de Streptococcus mutans foi pesquisado através da técnica de AP-PCR utilizando-se o primer OPA-13. Os fragmentos de DNA obtidos foram amplificados e comparados através de eletroforese em gel de agarose. Dentre as espécies identificadas nas 22 famílias analisadas, o pai apresentou cepas com similaridade genética aos dos bebês em três das famílias analisadas; em 12 famílias a mãe apresentou cepas com similaridade com as cepas de Streptococcus mutans do bebê e 7 bebês apresentaram cepas de S. mutans com similaridade genética das cepas do irmão mais velho. A técnica de AP-PCR foi eficaz em demonstrar a heterogeneidade genética de Streptococcus mutans entre os membros das famílias brasileiras analisadas.

Eficiência de uma solução para bochecho contendo triclosan/gantrez e bicarbonato de sódio associada à escovação na redução de placa e gengivite / Clinical effects of a mouthrinse solution containing triclosan/gantrez and baking soda used in association with regular toothbrushing on the reduction of plaque accumulation and marginal inflammation

Os enxaguatórios bucais são freqüentemente usados como adjuntos para a higiene oral, com o objetivo de melhorar a saúde gengival. O objetivo do presente estudo foi avaliar o efeito de uma solução para bochecho contendo triclosan/gantrez e bicarbonato de sódio utilizada em conjunto com a escovação, sobre o acúmulo de placa e inflamação marginal. Para efeito de comparação foram utilizadas soluções-controle positiva (clorexidina a 0,12 por cento) e negativa (placebo). Durante o período experimental de 21 dias, os 30 voluntários periodontalmente saudáveis selecionados não realizaram quaisquer procedimentos mecânicos de higiene interproximal, substituindo-os por dois bochechos diários de 1 minuto cada. Avaliações clínicas de placa visível e sangramento marginal foram realizadas aos 7, 14 e 21 dias. Os resultados indicaram que tanto a clorexidina (8,9 ± 8,9) quanto o triclosan (14,6 ± 8,1) reduziram significativamente o acúmulo de placa, em comparação ao placebo (24,0 ± 11,3). No entanto, apenas a clorexidina foi estatisticamente superior ao placebo na prevenção da inflamação marginal (9,8 ± 10,4 x 18,8 ± 12,4, respectivamente). Conclui-se que a solução testada, contendo triclosan/gantrez e bicarbonato de sódio, não proporcionou benefício significativo à saúde gengival em comparação à solução placebo